KINDAI UNIVERSITY


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IWAKI Masahiro

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FacultyDepartment of Pharmacy / Graduate School of Medicine / Pharmaceutical Research and Technology Institute
PositionProfessor
Degree
Commentator Guidehttps://www.kindai.ac.jp/meikan/792-iwaki-masahiro.html
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Last Updated :2020/08/10

Education and Career

Education

  •  - 1979 , Gifu Pharmaceutical University, Faculty of Pharmaceutical Science
  •  - 1979 , Gifu Pharmaceutical University, Faculty of Pharmaceutical Science

Academic & Professional Experience

  •   2018 04 ,  - 現在, Kindai University
  •   2018 04 ,  - 現在, Pharmaceutical Research and Technology Institute, Kindai University
  •   2016 10 ,  - 現在, Professor and Dean, Faculty of Pharmacy, Kindai University
  •   1996 ,  - 2000 , Kindai University
  •   2000 , Kindai University
  •   1990 ,  - 1996 , Kindai University
  •   1990 ,  - 1991 , University of California, San Francisco
  •   1979 ,  - 1990 , Research assistant, Faculty of Pharmacy, Kindai University
  •   1996 ,  - 2000 , Kinki University, Associated Professor
  •   2000 , - Kinki University, Professor
  •   1990 ,  - 1996 , Kinki University, Assistant Professor
  •   1990 ,  - 1991 , UCSF, Postdoctoral Fellow
  •   1979 ,  - 1990 , Kinki University, Research Assistant

Research Activities

Research Areas

  • Life sciences, Pharmacology
  • Life sciences, Clinical pharmacy, Pharmacokinetics

Research Interests

  • Stereoselective pharmacokinetics, Transporter, pharmacokinetics, Pharmacokinetics/Drug metabolism/Drug interactions

Published Papers

  • Radixin knockdown improves the accumulation and efficiency of methotrexate in tumor cells., Kawase A, Inoue Y, Nakazaki S, Koizumi E, Iwaki M, Oncology reports, Oncology reports, 42(1), 283 - 290, Jul. 2019 , Refereed
  • Involvement of diclofenac acyl-β-d-glucuronide in diclofenac-induced cytotoxicity in glutathione-depleted isolated murine hepatocytes co-cultured with peritoneal macrophages., Kawase A, Kaneto A, Ishibashi M, Kobayashi A, Shimada H, Iwaki M, Toxicology mechanisms and methods, Toxicology mechanisms and methods, 29(3), 203 - 210, Mar. 2019 , Refereed
  • Prediction of Hepatic Clearance of Stereoselective Metabolism of Carvedilol in Liver Microsomes and Hepatocytes of Sprague-Dawley and Cytochrome P450 2D-Deficient Dark Agouti Rats., Iwaki M, Niwa T, Tanaka H, Kawase A, Komura H, Journal of pharmacy & pharmaceutical sciences : a publication of the Canadian Society for Pharmaceutical Sciences, Societe canadienne des sciences pharmaceutiques, Journal of pharmacy & pharmaceutical sciences : a publication of the Canadian Society for Pharmaceutical Sciences, Societe canadienne des sciences pharmaceutiques, 22(1), 72 - 84, 2019 , Refereed
  • Suppression of Release of Matrix Metalloprotease-1 from Human Gingival Fibroblasts by Cimicifuga Rhizome Extract and a Novel Cimigenol Xyloside as an Active Constituent, Mami Honda-Yokota, Kazuya Murata, Takuya Anraku, Masahiro Iwaki, Natural Product Communications, Natural Product Communications, 13(10), 1259 - 1262, Oct. 2018 , Refereed
  • Correlation between glucuronidation and covalent adducts formation with proteins of nonsteroidal anti-inflammatory drugs, Shimada Hiroaki, Kobayashi Yuri, Tanahashi Sakiko, Kawase Atsushi, Ogiso Taro, Iwaki Masahiro, EUROPEAN JOURNAL OF PHARMACEUTICAL SCIENCES, EUROPEAN JOURNAL OF PHARMACEUTICAL SCIENCES, 112, 132 - 138, Jan. 15 2018 , Refereed
  • Relative contribution of rat CYP isoforms responsible for stereoselective metabolism of carvedilol, Iwaki Masahiro, Niwa Toshiro, Nakamura Yukiko, Kawase Atsushi, Komura Hiroshi, JOURNAL OF TOXICOLOGICAL SCIENCES, JOURNAL OF TOXICOLOGICAL SCIENCES, 43(1-3), 59 - 63, 2018 , Refereed
  • Stability evaluations of montelukast tablets under conditions of single dose packaging, Matsuura M, Otori T, Kawase A, Shimada H, Nakanishi H, Iwaki M, Int J Pharm Tech, Int J Pharm Tech, 9(4), 31079 - 31087, 2017 , Refereed
  • Stereoselective hepatic disposition of ibuprofen in the perfused liver of rat with adjuvant-induced arthritis., Uraki M, Kawase A, Iwaki M, Xenobiotica; the fate of foreign compounds in biological systems, Xenobiotica; the fate of foreign compounds in biological systems, 1 - 8, Nov. 2016 , Refereed
  • Development of a hybrid physiologically based pharmacokinetic model with drug-specific scaling factors in rat to improve prediction of human pharmacokinetics., Sayama H, Komura H, Kogayu M, Iwaki M, Journal of pharmaceutical sciences, Journal of pharmaceutical sciences, 102(11), 4193 - 4204, Nov. 2013 , Refereed
  • Increased effects of ginsenosides on the expression of cholesterol 7α-hydroxylase but not the bile salt export pump are involved in cholesterol metabolism., Kawase A, Yamada A, Gamou Y, Tahara C, Takeshita F, Murata K, Matsuda H, Samukawa K, Iwaki M, Journal of natural medicines, Journal of natural medicines, 67(3), 545 - 553, Jul. 2013 , Refereed
  • Application of the reconstructed rabbit corneal epithelium model to assess the in-vitro eye irritant test of chemicals., Matsuda S, Hisama M, Shibayama H, Itou N, Iwaki M, Yakugaku zasshi : Journal of the Pharmaceutical Society of Japan, Yakugaku zasshi : Journal of the Pharmaceutical Society of Japan, 129(9), 1113 - 1120, Sep. 2009 , Refereed
  • In vitro eye irritancy test of polyoxyethylene alkyl derivatives using a reconstructed rabbit corneal epithelium model, Matsuda S, Hisama M, Shibayama H, Itou N, Iwaki M, Biol. Pharm. Bull., Biol. Pharm. Bull., 32(5), 807 - 812, May 2009 , Refereed
  • Antimutagenic activity of a novel ascorbic derivative, disodium isostearyl 2-O-L-ascorbyl phosphate, Hisama M, Matsuda S, Shibayama H, Iwaki M, Yakugaku Zasshi, Yakugaku Zasshi, 128(6), 933 - 940, Jun. 2008 , Refereed
  • Comparative evaluation of 12 immature citrus fruit extracts for the inhibition of cytochrome P450 isoform activities, Fujita T, Kawase A, Niwa T, Tomohiro N, Masuda M, Matsuda H, Iwaki M, Biol. Pharm. Bull., Biol. Pharm. Bull., 31(5), 925 - 930, May 2008 , Refereed
  • Effect of a novel ascorbic derivative, disodium isostearyl 2-O-L-ascorbyl phosphate on human dermal fibroblasts: increased collagen synthesis and inhibition of MMP-1, Shibayama H, Hisama M, Matsuda S, Ohtsuki M, Iwaki M, Biol. Pharm. Bull., Biol. Pharm. Bull., 31(4), 563 - 568, Apr. 2008 , Refereed
  • Paclitaxel-2 '-ethylcarbonate prodrug can circumvent P-glycoprotein-mediated cellular efflux to increase drug cytotoxicity, Tadatoshi Tanino, Akihiro Nawa, Eisaku Kondo, Fumitaka Kikkawa, Tohru Daikoku, Tatsuya Tsurumi, ChenHong Luo, Yukihiro Nishiyama, Yuki Takayanagi, Katuhiko Nishimori, Seiji Ichida, Tetsuyuki Wada, Yasuyoshi Miki, Masahiro Iwaki, PHARMACEUTICAL RESEARCH, PHARMACEUTICAL RESEARCH, 24(3), 555 - 565, Mar. 2007 , Refereed
    Summary:Purpose: The aim of the study was to investigate whether 2'-ethylcarbonate-linked paclitaxel (TAX-2'-Et) circumvents P-glycoprotein (P-gp)-mediated cellular efflux and cytotoxicity enhanced by TAX-2'-Et activation within human culture cells transfected with a rabbit liver carboxylesterase (Ra-CES) cDNA. Materials and Methods: TAX-2'-Et transport was characterized in a human colon carcinoma cell line (Caco-2) and paclitaxel (TAX)-resistant ovarian carcinoma cells (SKOV3/TAX60). Expression of P-gp, multidrug resistance protein (MRP) 2 and Ra-CES was detected by Western blotting. Cytotoxicity against Ra-CES-expressing cells and cellular amount of TAX produced were determined by MTT assay and using HPLC, respectively. Results: Unlike rhodamine123 and TAX, TAX-2'-Et did not exhibit polarized transport in the Caco-2 cells in the absence or presence of verapamil. P-gp levels were expressed much higher in the SKOV3/TAX60 cells than in the Caco-2 cells. MRP2 protein was not detectable in the SKOV3/TAX60 cells. Uptake by the SKOV3/TAX60 cells was similar in quantity to the amount internalized by P-gp-negative SKOV3 cells. In the SKOV3/TAX60 cells, cellular uptake of TAX-2'-Et was not altered regardless of the absence or presence of verapamil. The cytotoxicity to the untransfected SKOV3 cells induced by TAX-2'-Et was significantly lower than that induced by TAX. In the Ra-CES-expressing SKOV3 line, the EC50 value of TAX (10.6 nM) was approximately four-fold higher than that of TAX-2'-Et (2.5 nM). Transfection of Ra-CES into another TAX-resistant ovarian carcinoma cells (KOC-7c) conferred a high level of TAX-2'-Et cytotoxicity via prodrug activation. The intracellular levels of TAX produced from TAX-2'-Et in the Ra-CES-positive KOC-7c cells significantly increased compared with the levels seen in exposure of the untransfected KOC-7c cells to TAX. Conclusions: TAX-2'-Et can circumvent P-gp-associated cellular efflux of TAX. TAX-2'-Et is converted into TAX by the Ra-CES, supporting its potential use as a theoretical GDEPT strategy for cancer cells expressing high levels of P-gp. The TAX-2'-Et prodrug efficiently increased the amount of intracellular TAX, which mediates tumor cell death.
  • Pitfall in in vitro high throughput screening system for absorption in drug discovery, Current Analytical Chemistry, Current Analytical Chemistry, 3, 302 - 309, 2007
  • Adsorption of cationic methylene blue and anionic methyl orange by crude drug starches, J. Appl. Glycosci., J. Appl. Glycosci., 52(1), 101 - 106, Jul. 2005
  • Nitrogen-containing bisphosphonate, YM529/ONO-5920 (a novel minodronic acid), inhibits RANKL expression in a cultured bone marrow stromal cell line ST2., Nishida S, Tsubaki M, Hoshino M, Namimatsu A, Uji H, Yoshioka S, Tanimori Y, Yanae M, Iwaki M, Irimajiri K, Biochem Biophys Res Commun., Biochem Biophys Res Commun., 328(1), 91 - 97, Mar. 2005 , Refereed
  • Effect of positively and negatively charged liposomes on skin permeation of drugs, T. Ogiso, T. Yamaguchi, M. Iwaki, T. Tanino, Y. Miyake, Journal Drug Targeting, Journal Drug Targeting, 9, 49 - 59, 2001
  • Chromatographic and capillary electrophoretic methods for the analysis of nicotinic acid and its metabolites, J. Chromatogr. B, J. Chromatogr. B, 747, 229-240(1/2), 229 - 240, 2000
  • Major constituents of Cistanche tubulosa, echinacoside and acteoside, inhibit sodium-dependent glucose cotransporter 1-mediated glucose uptake by intestinal epithelial cells, Shimada, Hiroaki, Urabe, Yuichi, Okamoto, Yuhei, Li, Zheng, Kawase, Atsushi, Morikawa, Toshio, Tu, Pengfei, Muraoka, Osamu, Iwaki, Masahiro, JOURNAL OF FUNCTIONAL FOODS, JOURNAL OF FUNCTIONAL FOODS, 39, 91 - 95, Dec. 2017 , Refereed
    Summary:Echinacoside (ECH) and acteoside (ACT), the major constituents of Cistanche tubulosa, suppress the increase in postprandial blood glucose level. Although ECH and ACT have been reported to weakly inhibit alpha-glucosidases, the underlying mechanism remains unclear. Therefore, we focused on the regulatory mechanism of dietary glucose absorption: In this study, we aimed to clarify the inhibitory effects of ECH and ACT on sodium-dependent glucose cotransporter (SGLT) 1-mediated gastrointestinal glucose absorption. Uptake experiments were performed using human intestinal Caco-2 cells and the fluorescence glucose analogue, 2-deoxy-2-[(7-nitro-2,1,3benzoxadiazol-4-yDaminc]-n-glucose (2-NBDG). Sodium-dependent 2-NBDG uptake was successfully estimated and this uptake was completely inhibited by an SGLT inhibitor phlorizin. ECH and ACT inhibited sodium-dependent 2-NBDG uptake in a concentration-dependent manner. However, this inhibition was not observed under sodium-free condition. This study suggested that the inhibitory effects of ECH and ACT on SGLT1-mediated glucose uptake contribute to suppression of increased postprandial blood glucose level.
  • A cell-based assay using HepaRG cells for predicting drug-induced phospholipidosis, Takafumi Tomida, Masakazu Ishimura, Masahiro Iwaki, JOURNAL OF TOXICOLOGICAL SCIENCES, JOURNAL OF TOXICOLOGICAL SCIENCES, 42(5), 641 - 650, Oct. 2017 , Refereed
    Summary:The utility of HepaRG cells as an in vitro cell-based assay system for predicting drug induced phospholipidosis (PLD) was investigated. In experiment 1, 10 PLD-positive compounds and 11 PLD-negative compounds were selected. HepaRG cells were treated with each compound for 48 hr. In experiment 2, loratadine and desloratadine, a major metabolite of loratadine, were used to assess metabolic activation for PLD. HepaRG cells were treated with loratadine and desloratadine in the presence or absence of 500 mu M 1-aminobenzotriazole (ABT), a broad CYP inhibitor, for 48 hr. After treatment with compounds in experiments 1 and 2, the relative fluorescence intensity (RFI) was measured using LYSO-ID Red dye to assess the PLD induction. In experiment 1, our cell-based assay system using HepaRG cells exhibited 100% sensitivity and 100% specificity for predicting drug-induced PLD. In experiment 2, loratadine increased the RFI in the PLD assay. However, the increase in the RFI was not observed in co-treatment with loratadine and ABT. In addition, desloratadine increased the RFI in the presence and absence of ABT. These results suggested that metabolic activation of loratadine may contribute to PLD in HepaRG cells. We newly demonstrated that HepaRG cells have a high ability for predicting drug-induced PLD. In addition, we newly showed that HepaRG cells may predict drug-induced PLD mediated by metabolic activation of loratadine. Thus, a cell-based assay system using HepaRG cells is a useful model for predicting drug-induced PLD.
  • Effects of High-cholesterol Diet on Pravastatin Disposition in the Perfused Rat Liver, Atsushi Kawase, Ayumi Handa, Masahiro Iwaki, EUROPEAN JOURNAL OF DRUG METABOLISM AND PHARMACOKINETICS, EUROPEAN JOURNAL OF DRUG METABOLISM AND PHARMACOKINETICS, 42(3), 519 - 526, Jun. 2017 , Refereed
    Summary:Background and Objectives Various nutrients modulate the expression of transporters; however, the effect of a high-cholesterol (HC) diet on the expression and function of hepatic transporters remains unclear. Here, we examined the effects of an HC diet on drug disposition via hepatic transporters, including organic anion-transporting polypeptide (Oatp), multidrug resistance-associated protein (Mrp), and bile salt export pump (Bsep). Methods In situ perfused rat liver system was performed. The levels of pravastatin, which is taken up into hepatocytes by Oatp and excreted into bile by Mrp2, in the perfusate and in bile were measured using high-performance liquid chromatography. Results Pravastatin was rapidly eliminated in control and HC rats; however, the cumulative amounts of excreted in bile were significantly higher in HC rats than in controls possibly because of the enhanced bile flow in HC rats (0.93 +/- 0.05 mu L/min in control, and 1.22 +/- 0.18 mu L/min in HC). Real-time reverse-transcriptase polymerase chain reaction (PCR) and western blot assessment of the mRNA and protein levels of hepatic transporters showed a significant downregulation of the Oatp1a1 and Bsep proteins in HC rats, whereas no differences in Mrp2 and Mrp3 levels were observed between HC and control rats. The analysis of the localization of Mrp2 on the canalicular membrane by immunofluorescence showed no changes in HC rats, although Mrp2 was readily internalized from the canalicular membrane under specific conditions. Conclusions The findings of the present study indicate that the HC diet affected the biliary excretion of pravastatin concomitant with increased bile flow, despite minimal effects on the expression of hepatic transporters. The HC diet could promote the biliary excretion of other drugs and metabolites that are substrates of Mrp2 and Bsep.
  • Inhibition of Methotrexate Uptake via Organic Anion Transporters OAT1 and OAT3 by Glucuronides of Nonsteroidal Anti-inflammatory Drugs, Masahiro Iwaki, Hiroaki Shimada, Yuri Irino, Manami Take, Sachiko Egashira, BIOLOGICAL & PHARMACEUTICAL BULLETIN, BIOLOGICAL & PHARMACEUTICAL BULLETIN, 40(6), 926 - 931, Jun. 2017 , Refereed
    Summary:Combination therapy of non-steroidal anti-inflammatory drugs (NSAIDs) and methotrexate (MTX) sometimes triggers adverse effects, such as liver injury, renal failure, gastrointestinal disorders, and myelosuppression, owing to the reduction of MTX clearance. Previous reports have suggested that NSAIDs inhibit renal MTX uptake via organic anion transporters (OATs) and reduced folate transporter (RFC)-1 and efflux via multidrug resistance-associated proteins (MRPs). Recently, our laboratory found inhibitory effects of NSAIDs-glucuronide (NSAIDs-Glu), a major metabolite of NSAIDs, on MRP-mediated MTX transport as a new site of interaction between MTX and NSAIDs. However, it remains unclear that whether NSAIDs-Glu inhibit renal uptake of MTX. Therefore, the present study aimed to evaluate inhibitory effects of several NSAIDs-Glu (diclofenac, R- and S-ibuprofen, R- and S-flurbiprofen, and R- and S-naproxen) on human OAT1 and OAT3-mediated MTX transport. In this study, [H-3]MTX uptake was observed by using human OAT1 and OAT3-overexpressing HEK293 cells in the presence or absence of NSAIDs-Glu. All examined NSAIDs-Glu exhibited concentration-dependent inhibitory effects on MTX uptake via OAT1 and OAT3. Our results indicated that NSAIDs-Glu are more potent (5- to 15-fold) inhibitors of OAT3 than OAT1. Moreover, stereoselective inhibitory effects of NSAIDs-Glu on OATs-mediated MTX uptake were not observed, unlike on MRPs-mediated transport. These findings suggest that inhibition of OAT1 and OAT3-mediated renal uptake of MTX by plasma NSAIDs-Glu may be one of the competitive sites underlying complex drug interaction between MTX and NSAIDs.
  • Involvement of Reactive Metabolites of Diclofenac in Cytotoxicity in Sandwich-Cultured Rat Hepatocytes, Atsushi Kawase, Ryota Hashimoto, Mai Shibata, Hiroaki Shimada, Masahiro Iwaki, INTERNATIONAL JOURNAL OF TOXICOLOGY, INTERNATIONAL JOURNAL OF TOXICOLOGY, 36(3), 260 - 267, May 2017 , Refereed
    Summary:Background and Objectives: Diclofenac (DIC) is metabolized to reactive metabolites such as diclofenac acyl--d-glucuronide (DIC-AG). It is possible that such reactive metabolites could cause tissue damage by formation of covalent protein adducts and other modification of cellular proteins or by induction of immune responses against its covalent protein adducts. However, the detailed mechanisms of idiosyncratic drug-induced liver injury (DILI) have been unclear. The objective is to clarify the involvement of DIC-AG and 4hydroxydiclofenac (4OH-DIC) in acute DILI.Methods:We examined the effects of inhibiting DIC-AG and 4OH-DIC production on covalent protein adduct formation and lactate dehydrogenase leakage using sandwich-cultured rat hepatocytes (SCRHs).Results:After pretreatment of SCRH with (-)-borneol (BOR, a uridine diphosphate (UDP)-glucuronosyltransferase inhibitor) or sulfaphenazole (SUL, a cytochrome P450 2C9 inhibitor) for 30 minutes, intracellular concentrations of DIC, DIC-AG, and 4OH-DIC were determined after further treating cells with 300 M DIC for 3 hours. The decreased levels of reactive metabolites caused by BOR or SUL pretreatment resulted in decreased lactate dehydrogenase leakage from SCRH, although the formation of covalent protein adducts was not affected.Conclusion:These results suggested that both DIC-AG and 4OH-DIC may be involved in acute cytotoxicity by DIC.
  • Effects of Adjuvant-Induced Inflammation on Disposition of Diclofenac and Its Metabolites in Perfused Rat Liver, Misato Uraki, Atsushi Kawase, Hiroyuki Sayama, Yuka Matsushima, Masahiro Iwaki, JOURNAL OF PHARMACEUTICAL SCIENCES, JOURNAL OF PHARMACEUTICAL SCIENCES, 106(4), 1175 - 1182, Apr. 2017 , Refereed
    Summary:The reactive metabolites of diclofenac (DF) such as 1-O-acyl glucuronide (DF-Glu) are hypothesized to result in idiosyncratic hepatotoxicity. However, it is unclear whether inflammation affects the hepatic disposition of DF and its metabolites. To clarify the alterations in the disposition of DF and its metabolites in inflammatory conditions, we performed in situ perfused rat liver experiments. Using adjuvant arthritis rats as a model of inflammation, the elimination of DF, 4'-hydroxydiclofenac, and DF-Glu from the perfusate was observed to be delayed in comparison with the control. Parameter sensitivity analysis for hepatic DF disposition revealed that the area under the plasma concentration-time curve (AUC) and the maximum concentration (C-max) of DF-Glu in the liver markedly increased along with a decrease in intrinsic excretion clearance of DF-Glu (CLint,bile,Glu) and an increase in intrinsic glucuronidation clearance (CLint,Glu) of DF-Glu. It is possible that the elimination of DF-Glu from the perfusate in adjuvant arthritis rats was delayed via reduction of biliary excretion of DF-Glu. (C) 2017 American Pharmacists Association (R). Published by Elsevier Inc. All rights reserved.
  • Stereoselective Pharmacokinetics and Chiral Inversion of Ibuprofen in Adjuvant-induced Arthritic Rats, Hiroyuki Ikuta, Atsushi Kawase, Masahiro Iwaki, DRUG METABOLISM AND DISPOSITION, DRUG METABOLISM AND DISPOSITION, 45(3), 316 - 324, Mar. 2017 , Refereed
    Summary:2-Arylpropionic acid (2-APA) nonsteroidal anti-inflammatory drugs are commonly used in racemic mixtures (rac) for clinical use. 2-APA undergoes unidirectional chiral inversion of the in vivo inactive R-enantiomer to the active S-enantiomer. Inflammation causes the reduction of metabolic activities of drug-metabolizing enzymes such as cytochrome P450 (P450) and UDP-glucuronosyltransferase. However, it is unclear whether inflammation affects the stereoselective pharmacokinetics and chiral inversion of 2-APA such as ibuprofen (IB). We examined the effects of inflammation on the pharmacokinetics of R-IB and S-IB after intravenous administration of rac-IB, R-IB, and S-IB to adjuvant-induced arthritic (AA) rats, an animalmodel of inflammation. The plasma protein binding of rac-IB, glucuronidation activities for R-IB and S-IB, and P450 contents of liver microsomes in AA rats were determined. Total clearance (CLtot) of IB significantly increased in AA rats, although the glucuronidation activities for IB, and P450 contents of liver microsomes decreased in AA rats. We presumed that the increased CLtot of IB in AA rats was caused by the elevated plasma unbound fraction of IB due to decreased plasma albumin levels in AA rats. Notably, CLtot ofR-IB but not S-IB significantly increased in AA rats after intravenous administration of rac-IB. These results suggested that AA could affect drug efficacies after stereoselective changes in the pharmacokinetics of R-IB and S-IB.
  • INHIBITION OF METHOTREXATE UPTAKE BY GLUCURONIDES OF NONSTEROIDAL ANTI-INFLAMMATORY DRUGS VIA ORGANIC ANION TRANSPORTERS OAT1 AND OAT3, Masahiro Iwaki, Yuri Irino, Manami Take, Sachiko Egashira, DRUG METABOLISM AND PHARMACOKINETICS, DRUG METABOLISM AND PHARMACOKINETICS, 32(1), S51 - S51, Jan. 2017 , Refereed
  • POTENTIAL OF PROSTAGLANDIN TRANSPORTER OATP2A1/SLCO2A1 AS A TARGET OF NOVEL ANTI-INFLAMMATORY DRUG, Hiroaki Shimada, Takeo Nakanishi, Yoshinobu Nakamura, Masahiro Iwaki, Ikumi Tamai, DRUG METABOLISM AND PHARMACOKINETICS, DRUG METABOLISM AND PHARMACOKINETICS, 32(1), S102 - S103, Jan. 2017 , Refereed
  • Development of hemiacetal esterified levofloxacin to prevent chelation with metal-containing drugs, Toru Otori, Sumio Matzno, Atushi Kawase, Masahiro Iwaki, Tetsutaro Kimachi, Keiji Nishiwaki, William C. Figoni, Ryuta Tominaga, Mai Asahide, Mayumi Nishikata, Yoshikazu Ishii, Kenji Matsuyama, JOURNAL OF PHARMACY AND PHARMACOLOGY, JOURNAL OF PHARMACY AND PHARMACOLOGY, 68(12), 1527 - 1534, Dec. 2016 , Refereed
    Summary:ObjectivesTo avoid the chelate formation between levofloxacin (LVFX) and aluminium hydroxide in gastrointestinal tract, an ethoxycarbonyl 1-ethyl hemiacetal ester of levofloxacin (LVFX-EHE) was synthesised as a prodrug. MethodsThe effects of aluminium hydroxide on the bioavailability of LVFX following oral administration of LVFX-EHE were investigated in rats. Furthermore, the effects of aluminium hydroxide on small intestinal absorption of LVFX and LVFX-EHE when subjected to a hydrolysis experiment using in situ everted gut sac were investigated, and the minimal inhibitory concentrations (MICs) of LVFX and LVFX-EHE for various intestinal bacteria were measured. Key findingsWhen LVFX-EHE was co-administered with and without aluminium hydroxide, the AUC(0-4 h) values of LVFX hydrolysed from LVFX-EHE were similar to that of LVFX alone. In everted gut sac experiments, LVFX-EHE was efficiently absorbed even in the presence of aluminium ions after 1 h of incubation, whereas the absorption of LVFX decreased significantly in the presence of aluminium ions. MIC values of LVFX-EHE were far higher than LVFX. ConclusionsThis study suggests the benefit of ethoxycarbonyl 1-ethyl hemiacetal esterification of the carboxyl group of new quinolone as a prodrug which is able to avoid chelate formation.
  • Application of substrate depletion assay to evaluation of CYP isoforms responsible for stereoselective metabolism of carvedilol, Masahiro Iwaki, Toshiro Niwa, Saya Bandoh, Megumi Itoh, Hitomi Hirose, Atsushi Kawase, Hiroshi Komura, DRUG METABOLISM AND PHARMACOKINETICS, DRUG METABOLISM AND PHARMACOKINETICS, 31(6), 425 - 432, Dec. 2016 , Refereed
    Summary:To evaluate the relative contribution of cytochrome P450 (CYP) isoforms responsible for carvedilol (CAR) oxidation, enantioselective metabolism of CAR was investigated in human liver microsomes (HLMs) and recombinant human CYPs by using the substrate depletion assay. CYP2D6 exhibited the highest contribution to the metabolism of R-CAR, followed by CYP3A4, CYP1A2, and CYP2C9, whereas the metabolism of the S-enantiomer was mainly mediated by CYP1A2, followed by CYP2D6 and CYP3A4. In HLMs, metabolism of R-and S-CAR was markedly inhibited by quinidine; R-CAR metabolism (57-61% decrease) was more inhibited than S-CAR metabolism (37-43% decrease), and furafylline and ketoconazole almost equally inhibited metabolism of both enantiomers by 25-32% and 30-50%, respectively. The absence of CYP2D6 in a mixture of five major recombinant CYP isoforms at the approximate ratio as in HLMs resulted in a 42% and 25% decrease in the metabolic activities for R-and S-CAR, respectively. Moreover, the absence of CYP1A2 in the mixture resulted in a 16% and 39% decrease in the metabolic activities for R-and S-CAR, respectively. Our results suggest the stereoselective metabolism of CAR is determined by not only the activity of CYP2D6 but also of CYP1A2 and CYP3A4. (C) 2016 The Japanese Society for the Study of Xenobiotics. Published by Elsevier Ltd. All rights reserved.
  • Inhibitory Activities of Sesame Seed Extract and its Constituents against beta-Secretase, Shinichi Matsumura, Kazuya Murata, Nobuhiro Zaima, Yuri Yoshioka, Masanori Morimoto, Hideaki Matsuda, Masahiro Iwaki, NATURAL PRODUCT COMMUNICATIONS, NATURAL PRODUCT COMMUNICATIONS, 11(11), 1671 - 1674, Nov. 2016 , Refereed
    Summary:The need for a preventive agent against dementia led us to screen natural plant resources. Among the herbs and spices tested, sesame seed prepared from Sesamum indicum seeds showed potent beta-secretase inhibitory activity. The active principles were determined to be sesamin and sesamolin, typical lignans in S. indicum. The IC50 values of sesamin and sesamolin were 257 and 140 mu M, respectively. These compounds were investigated in a preliminary absorption experiment. After oral administration, these compounds were detected in an intact form in the brain and serum. These results suggest that consumption of sesame seeds may prevent dementia by sesamin and sesamolin, the constituents in sesame seeds.
  • Effects of duration of phenytoin administration on mRNA expression of cytochrome P450 and P-glycoprotein in the liver and small intestine of rats, Atsushi Kawase, Hiroyuki Tanaka, Toru Otori, Kenji Matsuyama, Masahiro Iwaki, ASIAN JOURNAL OF PHARMACEUTICAL SCIENCES, ASIAN JOURNAL OF PHARMACEUTICAL SCIENCES, 11(5), 662 - 667, Oct. 2016 , Refereed
    Summary:Phenytoin (5,5-diphenylhydantoin; DPH) induces expression of cytochromes P450 (CYPs). Interactions between DPH and tacrolimus suggested that the persistence of CYP induction after discontinuation of DPH is dependent on the history of administration and dosing period of DPH. However, the relationship between the duration of DPH administration and expression of CYPs in the liver and small intestine of rats is not known. Alterations in levels of P-glycoprotein (P-gp; MDR1; ABCB1) as well as CYPs cause drug interactions in the small intestine. We examined the effects of the duration of DPH administration on expression of CYPs and P-gp in the liver and small intestine of rats. Rats were treated with DPH (100 mg/kg, peroral (p.o.) twice a day (b.d.)) for 2, 4, 8, and 16 d. mRNA levels of CYPs and P-gp were examined using the total RNA extracted from the liver and duodenum 2 h and 24 h after the final administration of DPH. CYP3A activities were determined using microsomes. DPH administration for 2 d and 4 d markedly increased mRNA levels of CYPs such as CYP3A1, CYP3A2, CYP2B1, and CYP2B2 in the liver. A relatively long duration of DPH administration (8 d and 16 d) resulted in abolition of the induction of hepatic CYP but increased CYP3A activities were maintained. These results suggest that the duration of DPH administration could be an important determinant of hepatic CYP induction. (C) 2016 Shenyang Pharmaceutical University. Production and hosting by Elsevier B.V.
  • Impact of a high-cholesterol diet on expression levels of Niemann-Pick C1-like 1 and intestinal transporters in rats and mice, Atsushi Kawase, Yasuha Araki, Yukiko Ueda, Sayaka Nakazaki, Masahiro Iwaki, EUROPEAN JOURNAL OF DRUG METABOLISM AND PHARMACOKINETICS, EUROPEAN JOURNAL OF DRUG METABOLISM AND PHARMACOKINETICS, 41(4), 457 - 463, Aug. 2016 , Refereed
    Summary:Niemann-Pick C1-like 1 (NPC1L1), ATP-binding cassette (ABC)G5, and ABCG8 are all involved in intestinal cholesterol absorption. It is unclear whether a high-cholesterol (HC) diet affects the expression of these transporters in rats and mice as well as humans. We examined the effects of an HC diet on their expression in small intestine and the differences between rats and mice in the responsive of this expression to an HC diet. In addition to these transporters, alterations in six representative drug and nutrient transporters (multidrug resistance-associated protein, breast cancer resistance protein, peptide transporter, sodium-glucose linked transporter, glucose transporter, and l-type amino acid transporter) and transcriptional factors such as hepatocyte nuclear factor (HNF)4 alpha, sterol regulatory element-binding protein (SREBP)2, and liver X receptor (LXR)alpha were determined. In rats and mice fed an HC diet for 7 days, the mRNA and protein levels of NPC1L1 in the small intestine were determined by real-time reverse transcription polymerase chain reaction and western blotting, respectively. The mRNA levels of ABCG5 and ABCG8, six representative transporters, and transcriptional factors such as HNF4 alpha, SREBP2, and LXR were examined. Significant decreases in the expression levels of NPC1L1 were observed in mice, but not rats, fed the HC diet. The mRNA levels of ABCG5 and ABCG8 were significantly increased in HC rats but not in mice. Only minor changes in the mRNA levels of the other transporters were seen in HC rats and mice. Decreased mRNA levels of HNF4 alpha and SREBP2 in mice could be involved in the reduction in NPC1L1 expression observed upon the introduction of an HC diet. These results indicate that the effects of an HC diet on the expression levels of NPC1L1, ABCG5, and ABCG8 differ between mice and rats.
  • Effects of dose, flow rate, and bile acid on diclofenac disposition in the perfused rat liver, Misato Uraki, Atsushi Kawase, Yuka Matsushima, Masahiro Iwaki, EUROPEAN JOURNAL OF DRUG METABOLISM AND PHARMACOKINETICS, EUROPEAN JOURNAL OF DRUG METABOLISM AND PHARMACOKINETICS, 41(3), 301 - 307, Jun. 2016 , Refereed
    Summary:An in situ perfused rat liver system is useful for studying the hepatic disposition of drugs and their metabolites. However, the effects of the perfusion conditions on drug disposition are unclear. We examined the effects of conditions such as flow rate (13 or 26 mL/min) and bile acid on disposition of diclofenac (DF) as a model drug and DF metabolites [diclofenac-1-O-acyl glucuronide (DF-Glu) or 4'-hydroxydiclofenac (DF-4'OH)] in the absence of albumin. DF, DF-Glu, and DF-4'OH concentrations in the perfusate and cumulative amounts of DF-Glu excreted in bile were measured using high-performance liquid chromatography methods. DF in the perfusate was rapidly eliminated as the perfusate flow rate increased. The area under the plasma concentration-time curve from 0 to 60 min (AUC(0-60)) for DF-Glu and DF-4'OH in a perfusate containing bile acid was lower at a flow rate of 26 and 13 mL/min, respectively. The bile flow rate at 26 mL/min with 24 mu M of bile acid in the perfusate was significantly higher (ca. 3.5 times) compared with that at 13 mL/min without bile acid. Cumulative biliary DF-Glu excretion was also dramatically affected by the flow rate and addition of bile acid. This study indicated that the flow rate and bile acid in the perfused rat liver were key factors for bile flow rate and DF, DF-Glu, and DF-4'OH disposition in the absence of albumin.
  • Stereoselective Inhibition of Methotrexate Excretion by Glucuronides of Nonsteroidal Anti-inflammatory Drugs via Multidrug Resistance Proteins 2 and 4, Atsushi Kawase, Taiki Yamamoto, Sachiko Egashira, Masahiro Iwaki, JOURNAL OF PHARMACOLOGY AND EXPERIMENTAL THERAPEUTICS, JOURNAL OF PHARMACOLOGY AND EXPERIMENTAL THERAPEUTICS, 356(2), 366 - 374, Feb. 2016 , Refereed
    Summary:Combined administration of methotrexate (MTX) and nonsteroidal anti-inflammatory drugs (NSAIDs) can result in a decreased systemic clearance of MTX. To date, inhibition of renal uptake via organic anion transporters and efflux via multidrug resistance-associated protein (MRPs) by NSAIDs has been recognized as possible sites of drug interaction between MTX and NSAIDs. Although most NSAIDs are glucuronidated in kidney tissue and excreted mainly as glucuronide conjugates, it is not fully known whether the glucuronides of NSAIDs (NSAIDs-Glu) inhibit MTX excretion via MRP2 and MRP4. The purpose of this study was to investigate the inhibitory effects of the glucuronides of several NSAIDs (diclofenac, R-and S-ibuprofen, R- and S-flurbiprofen, and R- and S-naproxen), as well as the parent NSAIDs on MTX uptake using human MRP2- and MRP4-expressing inside-out vesicles. Results confirm that all NSAIDs and NSAIDs-Glu examined exhibited stereoselective and concentration dependent inhibitory effects on MTX uptake via MRP2 and MRP4. Notably, NSAIDs-Glu potently inhibited MTX uptake via MRP2 and MRP4 compared with the corresponding parent NSAIDs except for naproxen in MRP2 and S-flurbiprofen in MRP4. The present results support that the glucuronides of NSAIDs, as well as the parent NSAIDs, are involved
  • DEVELOPMENT OF HEMIACETAL ESTERFIED NEW QUINOLONE TO PREVENT CHELATION WITH METAL CONTAINING DRUGS AND TO PREVENT PSEUDOMEMBRANOUS COLITIS, Kenji Matsuyama, Toru Otori, Atsusi Kawase, Masahiro Iwaki, Tetsutaro Kimachi, Yoshikazu Ishii, DRUG METABOLISM REVIEWS, DRUG METABOLISM REVIEWS, 47, 104 - 104, Nov. 2015 , Refereed
  • ALTERATIONS IN EXPRESSION AND FUNCTION OF EZIRIN/RADIXIN/MOESIN PROTEINS FOR TRANSPORTERS IN ADJUVANT-INDUCED ARTHRITIS RATS, Masahiro Iwaki, Atsushi Kawase, Misato Sakata, Misaki Nakasaka, Yukio Kato, DRUG METABOLISM REVIEWS, DRUG METABOLISM REVIEWS, 47, 275 - 275, Nov. 2015 , Refereed
  • Age-related changes in mRNA levels of hepatic transporters, cytochrome P450 and UDP-glucuronosyltransferase in female rats, Atsushi Kawase, Ayami Ito, Ayano Yamada, Masahiro Iwaki, EUROPEAN JOURNAL OF DRUG METABOLISM AND PHARMACOKINETICS, EUROPEAN JOURNAL OF DRUG METABOLISM AND PHARMACOKINETICS, 40(2), 239 - 244, Jun. 2015 , Refereed
    Summary:Hepatic transporters and metabolic enzymes affect drug pharmacokinetics. Limited information exists on the alteration in mRNA levels of hepatic transporters and metabolic enzymes with aging. We examined the effects of aging on the mRNA levels of representative hepatic drug transporters and metabolic enzymes by analyzing their levels in 10-, 30- and 50-week-old male and female rats. Levels of mRNA of drug transporters including multidrug resistance protein (Mdr)1a, multidrug resistance-associated protein (Mrp)2, breast cancer resistance protein (Bcrp) and organic anion-transporting polypeptide (Oatp)1a1, and the metabolic enzymes cytochrome P450 (CYP)3A1, CYP3A2 and UDP-glucuronosyltransferase (UGT)1A1 were analyzed using real-time reverse transcriptase polymerase chain reaction. The mRNA levels of transporters in male rats did not decrease with age, while the mRNA levels of Bcrp and Oatp1a1 in female rats decreased with age. The mRNA levels of CYP3A1 and CYP3A2 in male rats were higher than those in female rats. The mRNA levels of metabolic enzymes decreased with age in female but not male rats. In particular, the mRNA levels of UGT1A1 in 10-week-old female rats were higher than those in male rats. mRNA expression of hepatic transporters and metabolic enzymes are more susceptible to aging in female than male rats. The age-related decreases in the mRNA levels of Bcrp, Oatp1a1, CYP3A1 and CYP3A2 in female rats may affect the metabolism and transport of substrates. This study showed that aging affected the mRNA expression of hepatic transporters and metabolic enzymes in rats.
  • Pravastatin Modulate Niemann-Pick C1-Like 1 and ATP-Binding Cassette G5 and G8 to Influence Intestinal Cholesterol Absorption, Atsushi Kawase, Seiji Hata, Mai Takagi, Masahiro Iwaki, JOURNAL OF PHARMACY AND PHARMACEUTICAL SCIENCES, JOURNAL OF PHARMACY AND PHARMACEUTICAL SCIENCES, 18(5), 765 - 772, 2015 , Refereed
    Summary:Purpose. Niemann-Pick C1-like 1 (NPC1L1), ATP-binding cassette (ABC)G5, and ABCG8 mediate intestinal cholesterol absorption. It is unclear whether pravastatin (PR) or ezetimibe (EZ) affect expression of these transporters. We examined the effects of PR and EZ on NPC1L1, ABCG5, and ABCG8 expression in human hepatoma HepG2 cells and the murine small intestine. We also assessed expression of the transcription factors liver X receptor (LXR)alpha, LXR beta and sterol regulatory element-binding protein. Methods. Transporter mRNA levels were determined in murine small intestines 6 and 24 h after oral PR and EZ administration by real-time reverse-transcriptase polymerase chain reaction (RT-PCR). In PR-and EZ-treated HepG2 cells, transporter and transcription factor mRNA and protein levels were examined by RT-PCR and western blot, respectively. Results. Significant decreases in NPC1L1, ABCG5, and ABCG8 mRNA expression were observed in the duodenum, but not jejunum and ileum, of mice 24 h after treatment with PR, but not EZ. In HepG2 cells, PR but not EZ treatment for 24 h also significantly decreased NPC1L1 protein and ABCG5, and ABCG8 mRNA expression, while increasing LXR alpha mRNA levels. Conclusion. PR but not EZ treatment reduced duodenal cholesterol transporter expression in mice. PR-induced increases in LXR alpha mRNA levels may be involved in attenuation of NPC1L1 expression, subsequently decreasing intestinal cholesterol absorption.
  • Decreased Radixin Function for ATP-Binding Cassette Transporters in Liver in Adjuvant-Induced Arthritis Rats, Atsushi Kawase, Misato Sakata, Nagisa Yada, Misaki Nakasaka, Takuya Shimizu, Yukio Kato, Masahiro Iwaki, JOURNAL OF PHARMACEUTICAL SCIENCES, JOURNAL OF PHARMACEUTICAL SCIENCES, 103(12), 4058 - 4065, Dec. 2014 , Refereed
    Summary:Pathophysiological changes are associated with alterations in the expression and function of numerous ADME-related proteins. We have previously demonstrated that the membrane localization of ATP-binding cassette (ABC) transporters in liver was decreased without change of total expression levels in adjuvant-induced arthritis (AA) in rats. Ezrin/radixin/moesin (ERM) proteins are involved in localization of some ABC transporters in canalicular membrane. The mRNA levels of radixin decreased significantly in liver but not kidney, small intestine, and brain. The mRNA levels of ezrin and moesin did not change in AA. The membrane localization of radixin was reduced in liver of AA and the ratios of activated radixin (p-radixin) to total radixin were decreased in AA, although the protein levels of radixin did not change in homogenate and membrane protein. To clarify whether AA affects the linker functions of ERM proteins, we examined the interactions between ERM proteins and ABC transporters. The interactions between radixin and ABC transporters were decreased in AA. In vitro studies using human hepatoma HepG2 cells showed that interleukin-1 decreased the mRNA levels of radixin and colocalization of radixin and Mrp2. Our results show that the decreased radixin functions affect the interaction between radixin and ABC transporters in inflammation. (c) 2014 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 103:4058-4065, 2014
  • Application of a Physiologically Based Pharmacokinetic Model Informed by a Top-Down Approach for the Prediction of Pharmacokinetics in Chronic Kidney Disease Patients, Hiroyuki Sayama, Hiroaki Takubo, Hiroshi Komura, Motohiro Kogayu, Masahiro Iwaki, AAPS JOURNAL, AAPS JOURNAL, 16(5), 1018 - 1028, Sep. 2014 , Refereed
    Summary:Quantitative prediction of the impact of chronic kidney disease (CKD) on drug disposition has become important for the optimal design of clinical studies in patients. In this study, clinical data of 151 compounds under CKD conditions were extensively surveyed, and alterations in pharmacokinetic parameters were evaluated. In CKD patients, the unbound hepatic intrinsic clearance decreased to a similar extent for drugs eliminated via hepatic metabolism by cytochrome P450, UDP-glucuronosyltransferase, and other mechanisms. Renal clearance showed a similar decrease to glomerular filtration rate, irrespective of the contribution of tubular secretion. The scaling factor (SF) obtained from the interquartile range of the relative change in each parameter was applied to the well-stirred model to predict clearance in patients. Hepatic and renal clearance could be successfully predicted for approximately half and two-thirds, respectively, of the applied compounds, showing the high utility of SFs. SFs were also introduced to a physiologically based pharmacokinetic (PBPK) model, and the plasma concentration profiles of 12 model compounds with different elimination pathways were predicted for CKD patients. The PBPK model combined with SFs provided good predictability for plasma concentration. The developed PBPK model with information on SFs would accelerate translational research in drug development by predicting pharmacokinetics in CKD patients.
  • Distinct Alterations in ATP-Binding Cassette Transporter Expression in Liver, Kidney, Small Intestine, and Brain in Adjuvant-Induced Arthritic Rats, Atsushi Kawase, Sari Norikane, Ayaka Okada, Mamiko Adachi, Yukio Kato, Masahiro Iwaki, JOURNAL OF PHARMACEUTICAL SCIENCES, JOURNAL OF PHARMACEUTICAL SCIENCES, 103(8), 2556 - 2564, Aug. 2014 , Refereed
    Summary:Pathophysiological changes of infection or inflammation are associated with alterations in the production of numerous absorption, distribution, metabolism and excretion-related proteins. However, little information is available on the effects of inflammation on the expression levels and activities of ATP-binding cassette (ABC) transporters. We examined the effect of acute (on day 7) and chronic (on day 21) inflammation on the expression of ABC transporters in some major tissues in rat. Adjuvant-induced arthritis (AA) in rats was used as an animal model for inflammation. The mRNA levels of mdr1a and mdr1b encoding P-glycoprotein (P-gp) decreased significantly in livers of AA rats on day 21. Hepatic protein levels of P-gp, Mrp2, and Bcrp decreased significantly in membranes but not homogenates of AA rats after 7 days and after 21 days of treatment with adjuvant. Contrary to liver, protein levels of P-gp and Mrp2, but not Bcrp in kidney, increased significantly in membranes. The biliary excretion of rhodamine 123 was decreased in rats with chronic inflammation owing to decreases in efflux activities of P-gp. Our results showed that the expression of transporters in response to inflammation was organ dependent. In particular, hepatic and renal P-gp and Mrp2 exhibited opposite changes in membrane protein levels. (c) 2014 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 103:2556-2564, 2014
  • Effects of ginsenosides on the expression of cytochrome P450s and transporters involved in cholesterol metabolism, Atsushi Kawase, Ayano Yamada, Yuko Gamou, Chika Tahara, Fumiaki Takeshita, Kazuya Murata, Hideaki Matsuda, Keiichi Samukawa, Masahiro Iwaki, JOURNAL OF NATURAL MEDICINES, JOURNAL OF NATURAL MEDICINES, 68(2), 395 - 401, Apr. 2014 , Refereed
    Summary:An extract from red ginseng (steamed and dried roots of Panax ginseng C.A. Meyer; RGE) has been shown to promote cholesterol metabolism in the liver. We have reported that RGE induced the hepatic expression of cytochrome P450 (CYP)7A1, involved in cholesterol metabolism. Other cholesterol metabolism-related proteins, such as CYP8B1, CYP27A1, multidrug resistance-associated protein (MRP)2, MRP3, and Na+ taurocholate cotransporting polypeptide (NTCP), are involved in cholesterol metabolism. The purpose of this study was to clarify whether RGE affected mRNA expression of cholesterol metabolism-related CYPs and transporters in the liver of hypercholesterolemic rats and rat primary hepatocytes. In-vivo studies showed little differences in CYP8B1, CYP27A1, MRP2, MRP3, and NTCP mRNA expression levels between hypercholesterolemic rats with or without RGE treatments. However, the disruption of the membrane localization of MRP2 was suppressed by RGE treatments in hypercholesterolemic rats. In-vitro studies using rat primary hepatocytes showed upregulation of CYP8B1 and MRP2 mRNA by the addition of RGE (100 and 500 mu g/mL). We further examined which ginsenosides contributed to the upregulation of CYP8B1 and MRP2 mRNA levels. Ginsenoside Re enhanced the mRNA level of CYP8B1, whereas ginsenosides Rb-2 and Rg(2) enhanced MRP2 mRNA levels. These results suggest that the in-vitro exposure of hepatocytes to RGE or some ginsenosides could lead to upregulation of CYP8B1 and MRP2, resulting in the alteration of biosynthesis and disposition of bile acids.
  • Team-based Learning (TBL) in the Interdisciplinary Lecture, Keiji Nishiwaki, Atsushi Kawase, Tetsuyuki Wada, Hideki Yagi, Naohito Kawasaki, Eiji Ito, Masahiro Iwaki, YAKUGAKU ZASSHI-JOURNAL OF THE PHARMACEUTICAL SOCIETY OF JAPAN, YAKUGAKU ZASSHI-JOURNAL OF THE PHARMACEUTICAL SOCIETY OF JAPAN, 134(2), 171 - 177, Feb. 2014 , Refereed
    Summary:We conducted team-based learning (TBL) with interdisciplinary lectures as a part of "Introduction to Pharmacy", divided among the pharmacy department's six pharmacist education curricula in the first semester. The interdisciplinary lecture is led by seven lecturers, each specializing in one area: cell biology, biochemistry, chemistry, public health pharmacology, pharmacokinetics, and clinical science. This lecture's purpose is to demonstrate to the students that all field subjects relate to each other and they must learn the basic science subjects to understand pharmaceutical sciences. The TBL contents have two themes, "cancer" and "aspirin", each of which had two lectures, each 90 minutes long and were conducted using TBL as expansive learning. On receiving knowledge of a wide range of fields in one lecture, a small number of students indicated that they were unable to understand the contents very well. However, in the questionnaire about TBL, many students reported "I have understood" and "I have enjoyed studying" using TBL, especially group readiness assessment test (GRAT). By incorporating TBL, they reported "increasing eagerness to learn pharmacy". Overall, students seem to have accepted TBL favorably, but they still find peer review difficult. We believe that their discomfort with peer review results from their unfamiliarity in evaluating others, and the time before the evaluation is short because TBL is conducted only twice.
  • Alteration in plasma protein binding properties of propranolol and flurbiprofen during development of adjuvant-induced arthritis in rats, Atsushi Kawase, Hiroyuki Ikuta, Satoshi Uno, Kana Yamamoto, Naomi Akitsu, Tomoaki Nagao, Masahiro Iwaki, XENOBIOTICA, XENOBIOTICA, 43(3), 246 - 252, Mar. 2013 , Refereed
    Summary:Adjuvant-induced arthritis (AA) in the rat is used as a model for rheumatoid arthritis. In AA rats, the pharmacokinetics of various drugs is affected due to the alterations of plasma protein binding of drugs. We choose propranolol (PL) and flurbiprofen (FP) as model basic and acidic drugs, respectively, and investigated the effect of AA induction on their plasma protein binding at each developing stage of inflammation. The plasma protein binding of PL and FP was dramatically changed due to reduced albumin and increased alpha(1)-acid glycoprotein levels for at least 21 days after adjuvant treatment. Moreover, we illustrated the differences in protein binding in AA between both the drugs in each developing stage of inflammation. These results suggest that the changed plasma protein levels in AA rats accompanying the altered protein binding of drugs affect the pharmacokinetics of drugs which extensively bind to plasma protein under inflammatory condition.
  • In vitro and in vivo small intestinal metabolism of CYP3A and UGT substrates in preclinical animals species and humans: species differences, Hiroshi Komura, Masahiro Iwaki, DRUG METABOLISM REVIEWS, DRUG METABOLISM REVIEWS, 43(4), 476 - 498, Nov. 2011 , Refereed
    Summary:Intestinal first-pass metabolism has a great impact on the bioavailability of cytochrome P450 3A4 (CYP3A) and/or uridine 5'-diphosphate (UDP)-glucoronosyltranferase (UGT) substrates in humans. In vitro and in vivo intestinal metabolism studies are essential for clarifying pharmacokinetics in animal species and for predicting the effects of human intestinal metabolism. We review species differences in intestinal metabolism both in vitro and in vivo. Based on mRNA expression levels, the major intestinal CYP3A isoform is CYP3A4 for humans, CYP3A4 (3A8) for monkeys, CYP3A9 for rats, cyp3a13 for mice, and CYP3A12 for dogs. Additionally, the intestinal-specific UGT would be UGT1A10 for humans, UGT1A8 for monkeys, and UGT1A7 for rats. In vitro and in vivo intestinal metabolism of CYP3A substrates were larger in monkeys than in humans, although a correlation in intestinal availability between monkeys and humans has been reported. Little information is available regarding species differences in in vitro and in vivo UGT activities; however, UGT-mediated in vivo intestinal metabolism has been demonstrated for raloxifene in humans and for baicalein in rats. Further assessment of intestinal metabolism, particularly for UGT substrates, is required to clarify the entire picture of species differences.
  • Strain Differences in the Induction of Cytochrome P450 3A1/3A2 and Nuclear Receptors in the Liver by Phenobarbital and Dexamethasone in Sprague-Dawley Rats and Dark Agouti Rats, Atsushi Kawase, Toru Otori, Akiyuki Fujii, Ayano Yamada, Hiroshi Komura, Masahiro Iwaki, JOURNAL OF HEALTH SCIENCE, JOURNAL OF HEALTH SCIENCE, 57(5), 414 - 419, Oct. 2011 , Refereed
    Summary:Strain differences in the induction of cytochrome P450 (CYP) affect drug actions and side effects. Strain differences in the induction of CYP are important to evaluate drug-drug interactions in CYPs. We clarified strain differences in the induction of CYP3A1/3A2 and nuclear receptors by evaluating mRNA levels and metabolic activities in Sprague-Dawley (SD) rats and Dark Agouti (DA) rats (models for extensive and poor metabolism of CYP2D6, respectively). To clarify strain differences in CYP levels, we examined nuclear receptors such as the constitutive androstane receptor (CAR) and pregnane X receptor, which regulate the transcription of CYPs and transporters. We investigated CYP3A inductions in the liver after repeated intraperitoneal injections of phenobarbital (PB) or dexamethasone (DEX) into SD rats and DA rats for 3d. mRNA levels of CYP and nuclear receptors were determined by real-time reverse transcriptase-polymerase chain reaction. Metabolic activities of CYP3A were also determined. Increased CYP3A mRNA levels were observed in both rat strains after treatment with PB or DEX compared with the respective rat strains treated with vehicle alone. Induction of CYP3A mRNAs by DEX was higher in SD rats than in DA rats, suggesting that SD rats could be more susceptible to DEX than DA rats. Inductions of CAR by PB differed between strains. The increase in mRNA levels and activity of CYP3A by PB in SD rats and DA rats were similar. However, there were strain differences in CYP3A1/3A2 inductions after DEX treatment.
  • Enhanced Safety Profiles of the Telomerase-Specific Replication-Competent Adenovirus by Incorporation of Normal Cell-Specific microRNA-Targeted Sequences, Kumiko Sugio, Fuminori Sakurai, Kazufumi Katayama, Katsuhisa Tashiro, Hayato Matsui, Kenji Kawabata, Atsushi Kawase, Masahiro Iwaki, Takao Hayakawa, Toshiyoshi Fujiwara, Hiroyuki Mizuguchi, CLINICAL CANCER RESEARCH, CLINICAL CANCER RESEARCH, 17(9), 2807 - 2818, May 2011 , Refereed
    Summary:Purpose: Oncolytic adenoviruses (Ad) have been actively pursued as potential agents for cancer treatment. Among the various types of oncolytic Ads, the telomerase-specific replication-competent Ad (TRAD), which possesses an E1 gene expression cassette driven by the human telomerase reverse transcriptase promoter, has shown promising results in human clinical trials; however, the E1 gene is also slightly expressed in normal cells, leading to replication of TRAD and cellular toxicity in normal cells. Experimental Design: To overcome this problem, we utilized a microRNA (miRNA)-regulated gene expression system. Four copies of complementary sequences for miR-143, -145, -199a, or let-7a, which have been reported to be exclusively downregulated in tumor cells, were incorporated into the 3'-untranslated region of the E1 gene expression cassette. Results: Among the TRAD variants (herein called TRADs) constructed, TRADs containing the sequences complementary to miR-143, -145, or -199a showed efficient oncolytic activity comparable to the parental TRAD in the tumor cells. On the other hand, replication of the TRADs containing the miRNA complementary sequences was at most 1,000-fold suppressed in the normal cells, including primary normal cells. In addition, to suppress the replication of the TRADs in hepatocytes as well as other normal cells, we constructed a TRAD containing 2 distinct complementary sequences for miR-199a and liver-specific miR-122a (TRAD-122a/199aT). TRAD-122a/199aT exhibited more than 10-fold reduction in viral replication in all the normal cells examined, including primary hepatocytes. Conclusions: This study showed that oncolytic Ads containing the sequences complementary to normal cell-specific miRNAs showed significantly improved safety profiles without altering tumor cell lysis activity. Clin Cancer Res; 17(9); 2807-18. (C)2011 AACR.
  • A Trial of the Integrated Cross-field Pharmaceutical Education in the First Year of Faculty of Pharmacy, Tomohisa Yasuhara, Naohito Kawasaki, Hideki Yagi, Eiji Itoh, Atsushi Kawase, Toru Otori, Tetsuyuki Wada, Kenji Matsuyama, Masahiro Iwaki, YAKUGAKU ZASSHI-JOURNAL OF THE PHARMACEUTICAL SOCIETY OF JAPAN, YAKUGAKU ZASSHI-JOURNAL OF THE PHARMACEUTICAL SOCIETY OF JAPAN, 130(12), 1647 - 1653, Dec. 2010 , Refereed
    Summary:The six-year pharmacist education course has begun, and now first-year students receive clinical training. Interdisciplinary problem-solving capabilities covering chemistry, biology, molecular biology, pharmacology, pathology, and pharmacokinetics are necessary for new pharmacists. However, the conventional pharmaceutical science education was so separate from other fields that education for interdisciplinary cooperative capability was insufficient. This was especially true of elemental science courses, because they are not directly connected with clinical knowledge, and there is a problem of low student interest in those courses. As a result, students acquired only recall-level knowledge in clinical courses and their problem-solving capabilities in clinical treatment and drug development deteriorated. Therefore we offered a trial lecture aimed to help students recognize the important relationship between elemental science courses and clinical courses and increase their motivation to enroll in these courses. Specifically, the trial lecture covered cancer therapy, in reference to mechanisms of carcinogenesis, epidemiology, physiology of cancer, anticancer drugs with explanations of the mechanism of action of carcinogens, anticancer drugs, and molecular-targeted drugs from the viewpoints of organic chemistry and biochemistry by a specialized teacher. This paper reports on this experimental lecture with evaluations from students.
  • Inhibitory Effects of Phytoncide Solution on Melanin Biosynthesis, Hiroaki Fujimori, Masayoshi Hisama, Hiroharu Shibayama, Atsushi Kawase, Masahiro Iwaki, BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY, BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY, 74(5), 918 - 922, May 2010 , Refereed
    Summary:To determine the component-activity relationships of phytoncide solutions on inhibitory activity in melanin biosynthesis, four types of phytoncide solution (A-type, AB-type, D-type, and G-type) were evaluated for inhibition of mushroom tyrosinase activity and melanin synthesis on murine B-16 melanoma cells and a human reconstituted skin model. The A-type, AB-type, D-type, and G-type of phytoncide solution treatment resulted in significant inhibition of tyrosinase activity. The amount of melanin was increased by treatment with phytoncide solutions in a concentration-dependent manner on murine B-16 melanoma cells without affecting cell growth. Furthermore, phytoncide solutions also suppressed melanin synthesis in a concentration-dependent manner on a human reconstituted skin model. These effects of A-type solution were superior to those of other solutions.
  • Enhanced cytotoxicity with a novel system combining the paclitaxel-2 '-ethylcarbonate prodrug and an HSV amplicon with an attenuated replication-competent virus, HF10 as a helper virus, Daisuke Ishida, Akihiro Nawa, Tadatoshi Tanino, Fumi Goshima, Chen Hong Luo, Masahiro Iwaki, Hiroaki Kajiyama, Kiyosumi Shibata, Eiko Yamamoto, Kazuhiko Ino, Tatsuya Tsurumi, Yukihiro Nishiyama, Fumitaka Kikkawa, CANCER LETTERS, CANCER LETTERS, 288(1), 17 - 27, Feb. 2010 , Refereed
    Summary:We previously demonstrated that HF10, which is a natural, non-engineered HSV-1. has potent oncolytic activity in the treatment of solid malignant tumors in vitro and in vivo [H. Takakuwa, F. Goshima, N. Nozawa, T. Yoshikawa, H. Kimata, A. Nakao, et al., Oncolytic viral therapy using a spontaneously generated herpes simplex virus type 1 variant for disseminated peritoneal tumor in immunocompetent mice, Arch. Virol. 148 (2003) 813-825: S. Kohno, C. Lou, F. Goshima, Y. Nishiyama, T. Sata, Y. Ono, Herpes simplex virus type I mutant HF10 oncolytic viral therapy for bladder cancer, Urology 66 (2005) 1116-1121; D. Watanabe, F. Goshima, I. Mori, Y. Tamada, Y. Matsumoto, Y. Nishiyama, Oncolytic virotherapy for malignant melanoma with herpes simplex virus type 1 mutant HF10,J. Dermatol. Sci. 50 (2008) 185-196; A. Nawa, C. Luo, L. Zhang, Y. Ushijima, D. Ishida, M. Kamakura, et al., Non-engineered, naturally oncolytic herpes simplex virus HSV1 HF10: applications for cancer gene therapy, Curr. Gene. Ther. 8 (2008) 208-221]. Previous reports have also shown that a combination of HF10 and paclitaxel (TAX) was more efficacious than either regimen alone for some types of malignant tumors [S. Shimoyama, F. Goshima, O. Teshigahara, H. Kasuya, Y. Kodera, A Nakao, et al., Enhanced efficacy of herpes simplex virus mutant HF10 combined with paclitaxel in peritoneal cancer dissemination models, Hepatogastroenterology 54 (2007) 1038-1042]. In this study, we investigated the efficacy of gene-directed enzyme prodrug therapy (GDEPT) using a novel system that combines the paclitaxel-2'-ethylcarbonate prodrug (TAX-2'-Et) and an HSV amplicon expressing rabbit-carboxylesterase (CES) with HF10 as a helper virus. This GDEPT system aims to produce high level of CES at the tumor site, resulting in efficient local conversion of the TAX-2'-Et prodrug into the active drug TAX [A. Nawa, T. Tanino, C. Lou, M. Iwaki, H. Kajiyama, K. Shibata, et al., Gene directed enzyme prodrug therapy for ovarian cancer: could GDEPT become a promising treatment against ovarian cancer?, Anti-Cancer Agents Med Chem 8 (2008)232-239]. We demonstrated that the green fluorescent protein (GFP) gene, as a trace maker, was more efficiently introduced by the HSV amplicon compared to the expression vector, pHGCX, and that the HSV amplicon system expressed an active CES enzyme that could convert TAX-2'-Et to TAX in Cos7 cells. Furthermore, although the cytotoxicity of this amplicon system was not enhanced in virus-sensitive tumor cells, it was significantly enhanced in low virus-sensitive tumor cells in the presence of the prodrug in a concentration-dependent manner, compared to the control virus alone (p < 0.05). These results indicate that the addition of a prodrug converting enzyme may be a feasible approach to further enhance the efficacy of HF10 as a cancer therapeutics in low HF10-sensitive malignancies. (C) 2009 Elsevier Ireland Ltd. All rights reserved.
  • Ginseng Extracts Facilitate Cytochrome P450 Xenobiotic Metabolism in Primary Cultures of Rat Hepatocytes, Atsushi Kawase, Fumiaki Takeshita, Ayano Yamada, Kazuya Murata, Hideaki Matsuda, Keiichi Samukawa, Masahiro Iwaki, JOURNAL OF HEALTH SCIENCE, JOURNAL OF HEALTH SCIENCE, 55(5), 809 - 813, Oct. 2009
    Summary:A 70% methanol extract from red ginseng (steamed and dried roots of Panax ginseng C. A. Meyer, a kind of Ginseng Radix) has been shown to have various actions on physiological functions. We investigated whether the ginseng extract (Ext.) affected the mRNA expression of cytochrome P450 (CYP) CYP1A1, 2B1, 2C11, 2D1, 3A1, and 3A2 in rat primary hepatocytes. After treatment with ginseng extract, the levels of CYP3A1 and 1A1 mRNA were significantly increased compared with those of the control. The increased protein levels of CYP3A1 were also observed after treatment with Ext. The mRNA levels of other examined CYPs exhibited little change. The mRNA levels of the pregnane X receptor, but not the constitutive androstane receptor, both transcription factors for CYPs, also significantly increased after treatment with ginseng extract. These results raise the possibility that ginseng Ext. promotes xenobiotic metabolism via an increase in CYP3A1. and 1A1 expression.
  • Protecting Effect of Phytoncide Solution, on Normal Human Dermal Fibroblasts against Reactive Oxygen Species, Hiroaki Fujimori, Masayoshi Hisama, Hiroharu Shibayama, Masahiro Iwaki, JOURNAL OF OLEO SCIENCE, JOURNAL OF OLEO SCIENCE, 58(8), 429 - 436, Aug. 2009 , Refereed
    Summary:Four types of phytoncide solutions (A-Type, AB-Type, D-Type and G-Type) was evaluated for reduction of cell damage induced by oxidative stress, ultraviolet A (UVA), ultraviolet B (UVB), hydroxyperoxide (H2O2) and t-butyl-hydroperoxide (t-BHP); stimulation of collagen synthesis against UVA irradiation; and inhibition of matrix metalloproteinase-1 (MMP-1) activity induced by UVA in human normal dermal fibroblasts and human reconstituted skin model. The A-Type, AB-Type, D-Type and G-Type of phytoncide solutions pretreatment resulted in significant protection against cell damage induced by UVB, UVA, H2O2 and t-BHP. The amount of type I collagen following UVA irradiation was increased by treatment with phytoncide solutions in a concentration-dependent manner. On the other hand, phytoncide solutions also suppressed the excess MMP-1 irradiated UVA in a concentration-dependent manner. These effects of G-type solution were superior to those of other types solutions.
  • Organic anion transporting polypeptide 2-mediated uptake of paclitaxel and 2 '-ethylcarbonate-linked paclitaxel in freshly isolated rat hepatocytes, Tadatoshi Tanino, Akihiro Nawa, Mao Nakao, Manabu Noda, Sawako Fujiwara, Masahiro Iwaki, JOURNAL OF PHARMACY AND PHARMACOLOGY, JOURNAL OF PHARMACY AND PHARMACOLOGY, 61(8), 1029 - 1035, Aug. 2009 , Refereed
    Summary:Objectives The P-glycoprotein (P-gp) efflux pump plays an important role in paclitaxel detoxification. However, hepatic uptake of paclitaxel mediated by a solute-linked carrier transporter family is still poorly understood in animals and humans. Freshly isolated hepatocyte suspensions are a well established in-vitro model for studying drug transport and xenobiotic metabolism. Therefore, the hepatic uptake of paclitaxel and its P-gp-insensitive prodrug, 2'-ethylcarbonate-linked paclitaxel (TAX-2'-Et), has been characterized using freshly isolated and pregnenolone-16-alpha-carbonitrile (PCN)-treated hepatocytes in rats. Methods Paclitaxel and TAX-2'-Et were incubated with rat hepatocyte suspensions in the presence or absence of inhibitors. Key findings Paclitaxel and TAX-2'-Et showed concentration-dependent uptake in rat hepatocytes. The intrinsic transport capacity was two-fold higher for paclitaxel uptake than for TAX-2'-Et uptake. Rifampicin (a potent inhibitor of organic anion transporting polypeptide (Oatp) 2), but not indometacin (a representative inhibitor of organic anion transporter (Oat) 2 and Oatp1) treatment, significantly inhibited the uptake of paclitaxel and TAX-2'-Et. We characterized the rifampicin-sensitive uptake of paclitaxel and TAX-2'-Et using rat hepatocytes treated with PCN, which dramatically enhances hepatic Oatp2 protein levels. PCN-treated hepatocytes displayed a 1.6-fold greater uptake of paclitaxel and TAX-2'-Et than the vehicle-treated hepatocytes. The uptake of the two compounds was significantly reduced by rifampicin but not by indometacin treatment. These findings demonstrated that the rat Oatp2, but not Oatp1 or Oat2, was a candidate transporter for the hepatic uptake of paclitaxel and TAX-2'-Et. Conclusions The findings have provided an important step towards identifying a key transporter in hepatic detoxification of paclitaxel and TAX-2'-Et in small animals.
  • In vitro Eye Irritancy Test of Lauryl Derivatives and Polyoxyethylene Alkyl Derivatives with the Reconstructed Rabbit Corneal Epithelium Model, Sanae Matsuda, Masayoshi Hisama, Hiroharu Shibayama, Norihiko Itou, Masahiro Iwaki, JOURNAL OF OLEO SCIENCE, JOURNAL OF OLEO SCIENCE, 58(8), 437 - 442, Aug. 2009 , Refereed
    Summary:The rabbit corneal epithelium model (RCE model) was developed as a three-dimensional in vitro model to replace animal testing for the assessment of eye tolerance. In the model, a stratified culture of rabbit corneal epithelial cells is grown at the air-liquid interface on a collagen gel acting as a parabasal membrane. Histological cross-sections show that the structure of RCE model closely parallels that of the rabbit corneal epithelium. The lauryl derivatives, such as sodium lauryl sulfate (SLS), polyoxyethylene (9) lauryl ether (PLE), sodium polyoxyethylene (2) lauryl ether sulfate (SPLE), mono glyceryl laurate (MGL), and sodium N-lauroyl-L-glutaminate (SLG), and polyoxyethylene alkyl derivatives, polyoxyethylene (9) lauryl ether (PLE), polyoxyethylene (10) cetyl ether (PCE), polyoxyethylene (10) stearyl ether (PSE), polyoxyethylene (10) oleyl ether (POE), and polyoxyethylene (10) behenyl ether (PBE), were evaluated for in vitro eye irritation potential using the RCE model by the measurement of viability with MTT assay. SLS, PLE, SPLE, MGL, and SLG inhibited 90.3%, 69.8%, 79.7%, 45.8%, and 32.7% of the viability at a concentration of 0.5%. The IC50 (50% inhibitory concentration) values of SLS, PLE, SPLE, MGL, and SLG were 0.086%, 0.205%, 0.133%, 0.627%, and 0.934%, respectively. These results indicated that a functional group at the end of lauryl chain is an important factor for inhibiting the viability using the RCE model. The polyoxyethylene alkyl derivatives had distinctly different the viability potencies according to their alkyl patterns. PLE inhibited the viability greater than other polyoxyethylene alkyl derivatives. Therefore, the lauryl chain of PLE is an important factor for inhibiting the viability on the RCE model.
  • In vitro eye irritancy test of lauryl derivatives using the reconstructed rabbit corneal epithelium model, Sanae Matsuda, Masayoshi Hisama, Hiroharu Shibayama, Norihiko Itou, Masahiro Iwaki, TOXICOLOGY IN VITRO, TOXICOLOGY IN VITRO, 23(4), 555 - 560, Jun. 2009 , Refereed
    Summary:The rabbit corneal epithelium model (RCE model) was developed as a three-dimensional in vitro model to replace animal testing for the assessment of eye tolerance. In the model, a stratified culture of rabbit corneal epithelial cells is grown at the air-liquid interface on an amniotic membrane acting as a para-basal membrane, The alkaline exposure was restored each day in the presence of no irritants, although with the addition of SLS, which is a major irritant, the restoration of deficit was inhibited on the RCE model in a dose-dependent manner. The results of this test were comparable with those of the Draize test, and thus, this method using the RCE model may prove to be a useful and sensitive in vitro eye irritation test. The lauryl fatty chain derivatives, such as polyoxyethylene (9) lauryl ether (PLE), sodium polyoxyethylene (2) lauryl ether sulfate (SPLE), mono glyceryl laurate (MGL), and sodium N-lauroyl-L-glutaminate (SLG), which are widely used as surfactants for toiletry products and cosmetics. were evaluated for in vitro eye irritation potential using the RCE model. SLS, PLE, SPLE, MGL, and SLG inhibited 88.7%, 59.2%. 69.0%, 47.5%, and 15.7% of the restoration of deletion 24 h after treatment at a concentration of 0.05%. The IC(50) (50% inhibitory concentration) values of SLS, PLE, SPLE, MGL and SLG were 0.002%, 0.021%, 0.005%, 0.056%, and 0.448%, respectively. These results indicated that a functional group at the end of lauryl chain is an important factor for inhibiting the restoration of deletion using the RCE model. (C) 2009 Elsevier Ltd. All rights reserved
  • Differential Effects of Chrysin on Nitrofurantoin Pharmacokinetics Mediated by Intestinal Breast Cancer Resistance Protein in Rats and Mice, Atsushi Kawase, Yukako Matsumoto, Motoshi Hadano, Yui Ishii, Masahiro Iwaki, JOURNAL OF PHARMACY AND PHARMACEUTICAL SCIENCES, JOURNAL OF PHARMACY AND PHARMACEUTICAL SCIENCES, 12(2), 150 - 163, 2009 , Refereed
    Summary:Purpose. The activities of breast cancer resistance protein (Bcrp/ABCG2) as well as P-glycoprotein (P-gp) and drug-metabolizing enzymes can be inhibited by several flavonoids or drugs in rats. However, the species, sex and regional differences of effects of flavonoids on Bcrp/ABCG2 in rats and mice remain unclear, although Bcrp, like P-gp, is also important in controlling drug absorption and disposition. Methods. We used chrysin as a model flavonoid because it possesses anti-inflammatory and antioxidative properties and is used as a dietary supplement. We examined the pharmacokinetics of nitrofurantoin, a specific Bcrp substrate, after oral or intravenous administration in rats and mice treated with chrysin. Bcrp mRNA levels were measured in liver, kidney, duodenum, jejunum and ileum in rats and mice. Results. Oral chrysin increased plasma concentrations of nitrofurantoin in rats but not mice. Intraperitoneal injection of chrysin into rats or mice had little effect on the elimination of nitrofurantoin. The AUC(0-t) in female mice was 1.5-2.0 folds higher than in male mice after oral and intravenous administration of nitrofurantoin. Absorption of nitrofurantoin from apical to basal sides was significantly increased by chrysin in both duodenum and jejunum as well as in ileum in rat small intestine. Conclusions. Chrysin-nitrofurantoin interactions it takes place in the small intestine and occur in rats, but not in mice, possibly due to the higher levels of Bcrp in the small intestine in rats as compared with mice.
  • Changes in mRNA Expression of ABC and SLC Transporters in Liver and Intestines of the Adjuvant-induced Arthritis Rat, Satoshi Uno, Misato Uraki, Ayami Ito, Yuki Shinozaki, Ayano Yamada, Atsushi Kawase, Masahiro Iwaki, BIOPHARMACEUTICS & DRUG DISPOSITION, BIOPHARMACEUTICS & DRUG DISPOSITION, 30(1), 49 - 54, Jan. 2009 , Refereed
    Summary:In this study, a real-time reverse transcription-polymerase chain reaction was used to determine the effects of adjuvant-induced arthritis (AA) on the amounts of mRNA of 12 types of rat ATP-binding cassette (ABC) and solute carrier (SLC) transporters in the liver and small intestine, 7 (D7) and 21 days (D21) after the injection of adjuvant. There were no significant differences in mRNA levels of ABC and SLC transporters between the livers of AA and control rats on D7, except in the case of Mdr1a. However, levels of Mdr1a, Mrp2 and Cap SLC transporters were significantly lower in AA than in the control livers on D21. In contrast, the mRNA levels of several ABC and SLC transporters, especially Mrp2, Bcrp, LAT2 and Oatp1a5, were significantly lower in the small intestines of AA rats compared with the controls on D7, though there were no significant differences by D21. The time-dependent alterations in mRNA levels of the pregnane X receptor, but not the constitutive androstane receptor, in the liver and intestine were similar to the changes in mRNA levels of most transporters examined. The present study showed that AA was associated with reduced mRNA expression of several ABC and SLC transporters in the liver and small intestine, but that the time courses of the effects of AA on mRNA expression differed between the liver and small intestine. These results raise the possibility of a functional change of the transporters of liver and intestine in AA rats. Copyright (C) 2009 John Wiley & Sons, Ltd.
  • Suppression of Mutagens-induced SOS Response by Phytoncide Solution Using Salmonella typhimurium TA1535/pSK1002 umu Test, Masayoshi Hisama, Sanae Matsuda, Tomomi Tanaka, Hiroharu Shibayama, Masato Nomura, Masahiro Iwaki, JOURNAL OF OLEO SCIENCE, JOURNAL OF OLEO SCIENCE, 57(7), 381 - 390, Jul. 2008 , Refereed
    Summary:Four types of phytoncide solution (A-Type, AB-Type, D-Type and G-Type) were evaluated as antimutagenic agents with suppressive effects on the SOS-inducing activity of the mutagen 2-(2-furyl)-3-(5-nitro-2-furyl) acrylamide (furylfuramide) using Salmonella typhimurium TA 1535/pSK 1002 umu test. The A-Type, AB-Type, D-Type and G-Type of phytoncide solution suppressed the SOS-inducing activity on furylfuramide at a concentration of 100 mu g/mL by 86.1%, 74.7%, 69.5% and 55.4%, respectively, and the ID50 (50% inhibitory dose) values were 9.0 mu g/mL, 22.5 mu g/mL, 36.0 mu g/mL and 72.8 mu g/ml.. They also showed the suppression of SOS-inducing activity against other chemical mutagens, such as 4-nitroquinolin I-oxide (4NQO). and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), which do not require liver metabolizing enzymes, and against 2-aminoanthracene (2AA) and 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]-indole (Trp-P-1), which require these enzymes, and against UV irradiation, which is a well known physical mutagen. In the search for the component-activity relationship, the A-Type of phutoncide solution suppressed the SOS-inducing activity greater than the other types of phutoncide solution for furylfuramide, 4NQO and MNNG. However, in case of 2AA and Trp-P-1, the D-Type of phytoncide solution was most effective in suppressing the SOS-inducing activity in the umu test. From these results, the four types of phytoncide solutions showed the suppressive effect of SOS-inducing activity against chemical and physical mutagens.
  • Enzymatic stability of 2'-ethylcarbonate-linked paclitaxel in serum and conversion to paclitaxel by rabbit liver carboxylesterase for use in prodrug/enzyme therapy, Tadatoshi Tanino, Akihiro Nawa, Yasuyoshi Miki, Masahiro Iwaki, BIOPHARMACEUTICS & DRUG DISPOSITION, BIOPHARMACEUTICS & DRUG DISPOSITION, 29(5), 259 - 269, Jul. 2008 , Refereed
    Summary:In prodrug/enzyme therapy for cancer, information on the sensitivity of hydrolytic enzymes to prodrug is required to reduce adverse effects of the parental drug and to find the activating enzyme. The aim of this study was to characterize the enzymatic stability of 2'-ethylcarbonate-linked paclitaxel (TAX-2'-Et) in the sera of several different species including humans. TAX-2-Et disposition in serum was kinetically analysed using models with hydrolytic and/or degradation processes. To further evaluate the capability of liver carboxylesterases (CESs) in TAX-2-Et hydrolysis, a CES isolated from rabbit liver (Ra-CES) was utilized as a model enzyme. Rat serum provided rapid enzymatic hydrolysis of TAX-2'-Et with a half-life of 4min. The degradation of paclitaxel (TAX) (degradation rate constant, 0.16h-1) was accompanied by the formation of an unknown compound. The conversion to TAX was almost completely inhibited by phenylmethyl sulfonylfluoride (PMSF) and bis(p-nitrophenyl) phosphate (BNPP). In human and rabbit sera, the degradation rate constant of TAX-2'-Et was 5.1 X 10-2 and 0.15h-', respectively, when excepting hydrolysis. The degradation products had the same molecular weight as TAX-2-Et. The amount of TAX produced accounted for only 8-11% of the decrease in TAX-2'-Et after a 9 h exposure to rabbit or human serum. PMSF, but not BNPP, inhibited more than 90% of the TAX production in a 1.5 h incubation with human or rabbit serum. Ra-CES enzyme converted TAX-2'-Et to TAX with V,, x and K. of 74.7 + 13.8 nmol/min/mg protein and 8.8 + 2.8 pm, respectively. These results indicate that TAX-2'-Et is sensitive to serum CESs, but not cholinesterases. However, serum CESs show species-dependent hydrolysis of TAX-2'-Et. Although human serum allows the slow release of TAX, TAX-2'-Et is expected to reduce the side-effects of TAX. The Ra-CES enzyme is capable of hydrolysing TAX-2'-Et, which may be beneficial for the development of a TAX-2'-Et/ enzyme therapy strategy for ovarian cancer. Copyright (c) 2008 John Wiley & Sons, Ltd.
  • Species differences in in vitro and in vivo small intestinal metabolism of CYP3A substrates, Hiroshi Komura, Masahiro Iwaki, JOURNAL OF PHARMACEUTICAL SCIENCES, JOURNAL OF PHARMACEUTICAL SCIENCES, 97(5), 1775 - 1800, May 2008 , Refereed
    Summary:Intestinal first-pass metabolism has a great impact on the bioavailability of CYP3A substrates in humans, and the in vivo impact has quantitatively been evaluated using CYP3A inhibitors or inducers. In vitro and in vivo preclinical investigations for intestinal metabolism are essential in clarifying pharmacokinetic behavior in animal species and predicting the effect of intestinal metabolism in the human. In this review, we will discuss species differences in intestinal CYP3A enzymes, and CYP3A-mediated intestinal elimination. Identical CYNA4 enzyme is expressed in human intestine and liver, but different CYP3A enzymes in both tissues of the mouse and rat are found, that is, respective intestinal enzyme is considered as cyp3a13 and Cyp3A62. There is little information on CYP3A enzymes in the monkey and dog intestine, unlike the liver. In vitro metabolic activities of midazolam and nisoldipine are higher in the human and monkey than in the rat. In vivo assessment of cyclosporine, midazolam, nifedipine, tacrolimus, and verapamil has been reported in various species (monkey, rat, mouse, and/or dog) including the human. For midazolam, the monkey shows significant in vivo intestinal metabolism, as evidenced in the human. The monkey might be an appropriate animal model for evaluating small intestinal first-pass metabolism of CYP3A substrates. (c) 2007 Wiley-Liss, Inc. and the American Pharmacists Association.
  • Species differences in in vitro and in vivo small intestinal metabolism of CYP3A substrates, Hiroshi Komura, Masahiro Iwaki, JOURNAL OF PHARMACEUTICAL SCIENCES, JOURNAL OF PHARMACEUTICAL SCIENCES, 97(5), 1775 - 1800, May 2008
    Summary:Intestinal first-pass metabolism has a great impact on the bioavailability of CYP3A substrates in humans, and the in vivo impact has quantitatively been evaluated using CYP3A inhibitors or inducers. In vitro and in vivo preclinical investigations for intestinal metabolism are essential in clarifying pharmacokinetic behavior in animal species and predicting the effect of intestinal metabolism in the human. In this review, we will discuss species differences in intestinal CYP3A enzymes, and CYP3A-mediated intestinal elimination. Identical CYNA4 enzyme is expressed in human intestine and liver, but different CYP3A enzymes in both tissues of the mouse and rat are found, that is, respective intestinal enzyme is considered as cyp3a13 and Cyp3A62. There is little information on CYP3A enzymes in the monkey and dog intestine, unlike the liver. In vitro metabolic activities of midazolam and nisoldipine are higher in the human and monkey than in the rat. In vivo assessment of cyclosporine, midazolam, nifedipine, tacrolimus, and verapamil has been reported in various species (monkey, rat, mouse, and/or dog) including the human. For midazolam, the monkey shows significant in vivo intestinal metabolism, as evidenced in the human. The monkey might be an appropriate animal model for evaluating small intestinal first-pass metabolism of CYP3A substrates. (c) 2007 Wiley-Liss, Inc. and the American Pharmacists Association.
  • Paclitaxel-2 '-ethylcarbonate prodrug can circumvent P-glycoprotein-mediated cellular efflux to increase drug cytotoxicity, Akihiro Nawa, Tadatoshi Tanino, Hiroaki Kajiyama, Kiyosumi Shibata, Masahiro Iwaki, Fumitaka Kikkawa, JOURNAL OF GENE MEDICINE, JOURNAL OF GENE MEDICINE, 10(4), 475 - 476, Apr. 2008 , Refereed
  • Effect of a novel ascorbic derivative, disodium isostearyl 2-O-L-ascorbyl phosphate, on normal human dermal fibroblasts against reactive oxygen species, Hiroharu Shibayama, Masayoshi Hisama, Sanae Matsuda, Atsushi Kawase, Mamitaro Ohtsuki, Katsumi Hanada, Masahiro Twaki, BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY, BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY, 72(4), 1015 - 1022, Apr. 2008 , Refereed
    Summary:The novel amphiphilic vitamin C derivative disodium isostearyl 2-O-L-ascorbyl phosphate (VCP-IS-2Na), which has a C-18 alkyl chain attached to the stable ascorbate derivative sodium L-ascorbic acid 2-phosphate (VCP-Na), was evaluated for reduction of cell damage induced by oxidative stress, ultraviolet A (UVA), ultraviolet B (UVB), and H2O2; stimulation of collagen synthesis against UVA irradiation; and inhibition of matrix metalloproteinase-1 (MMP-1) activity induced by UVA in human normal dermal fibroblasts. VCP-IS-2Na pretreatment resulted in significant protection against cell damage induced by UVB, UVA, and H2O2. The amount of type I collagen following UVA irradiation was increased by treatment with VCP-IS-2Na in a concentration-dependent manner. These effects of VCP-IS-2Na were superior to those Of L-ascorbic acid (vitamin C, VC) and VCP-Na. On the other hand, VCP-IS-2Na suppressed 65% of the excess MMP-1 irradiated UVA, and VC and VCP-Na slightly suppressed it.
  • Anti-allergic effect of a combination of Citrus unshiu unripe fruits extract and prednisolone on picryl chloride-induced contact dermatitis in mice, Tadashi Fujita, Takehumi Shiura, Megumi Masuda, Masashi Tokunaga, Atsushi Kawase, Masahiro Iwaki, Takeshi Gato, Masahiko Fumuro, Katsuaki Sasaki, Naoki Utsunomiya, Hideaki Matsuda, JOURNAL OF NATURAL MEDICINES, JOURNAL OF NATURAL MEDICINES, 62(2), 202 - 206, Apr. 2008 , Refereed
    Summary:Effect of 50% ethanolic extract of unripe fruits of Citrus unshiu (CU-ext) on type IV allergic reaction was examined by inhibitory activity of ear swelling of picryl chloride-induced contact dermatitis (PC-CD) in mice. Oral administration of CU-ext and subcutaneous administration of prednisolone showed inhibition of ear swelling during both induction and effector phases of PC-CD. The inhibitory activities of combinations of CU-ext (p.o.) and prednisolone (s.c.) during induction phase of PC-CD were more potent than those of CU-ext alone and prednisolone alone. Successive oral administration of hesperidin, a major flavanone glycoside of CU-ext, inhibited ear swelling during induction phase of PC-CD. The inhibitory activities of combinations of hesperidin (p.o.) and prednisolone (s.c.) were more potent than those of hesperidin alone and prednisolone alone. These results indicated that the combinations of prednisolone and CU-ext or hesperidin exerted a synergistic effect.
  • Inhibitory effects of a novel ascorbic derivative, disodium isostearyl 2-O-L-ascorbyl phosphate on melanogenesis, Sanae Matsuda, Hiroharu Shibayama, Masayoshi Hisama, Mamitaro Ohtsuki, Masahiro Iwaki, CHEMICAL & PHARMACEUTICAL BULLETIN, CHEMICAL & PHARMACEUTICAL BULLETIN, 56(3), 292 - 297, Mar. 2008 , Refereed
    Summary:We investigated the inhibitory effects of a novel amphiphilic ascorbic derivative, disodium isostearyl 2-O-L-ascorbyl phosphate (VCP-IS-2Na), synthesized from a hydrophilic ascorbic derivative, sodium-2-O-L-ageorbyl phosphate (VCP-Na), on melanogenesis in cultured human melanoma cells, normal human melanocytes, and three-dimensional cultured human skin models. Melanin synthesis in melanoma cells treated with VCP-TS-2Na at 300 mu M and melanocytes treated with VCP-IS-2Na at 100 mu m decreased to 23% and 52% of that in non-treated cells, respectively, and the cell viability was not affected. VCP-IS-2Na also significantly suppressed the cellular tyrosinase activity of melanoma cells and melanocytes. Melanin synthesis in human skin models was evaluated by macro- and microscopic observations of its pigmentation and quantitative measurements of melanin. Treatment of the human skin models with 1.0% VCP-IS-2Na did not inhibit cell viability, while melanin synthesis was decreased to 21% of that in the control. In contrast, L-ascorbic acid (VC) and VCP-Na did not seem to inhibit melanin synthesis and cellular tyrosinase activity. These results indicate that VCP-IS-2Na may be an effective whitening agent for the skin, and we expect the application of VCP-IS-2Na in the cosmetic industry.
  • Gene directed enzyme prodrug therapy for ovarian cancer: Could GDEPT become a promising treatment against ovarian cancer?, Akihiro Nawa, Tadatoshi Tanino, ChenHong Luo, Masahiro Iwaki, Hiroaki Kajiyama, Kiyosumi Shibata, Eiko Yamamoto, Kazuhiko Ino, Yukihiro Nishiyama, Fumitaka Kikkawa, ANTI-CANCER AGENTS IN MEDICINAL CHEMISTRY, ANTI-CANCER AGENTS IN MEDICINAL CHEMISTRY, 8(2), 232 - 239, Feb. 2008 , Refereed
    Summary:Gene-directed enzyme prodrug therapy (GDEPT) involves the treatment concept of having maximal efficacy and minimal adverse effects. Several GDEPT strategies have been developed combining cytosine deaminase and 5-fluorocytosine, cytochrome P450 2B1 and cyclophosphamide, and carboxylesterase (CES) and irinotecan in experimental models. The active forms of these prodrugs, however, are not a frontline therapy for the treatment of ovarian cancer. It would be beneficial to develop a more effective prodrugenzyme combination for the treatment of this disease. Paclitaxel (Taxol(R); TAX) is currently one of the most important anti-cancer drugs in chemotherapy of ovarian cancer. One of TAX prodrugs, 2'-ethylcarbonate-linked paclitaxel (TAX-2'-Et), was generated and examined regarding its pharmacological aspects. The prodrug of TAX-2'-Et converts into active form TAX by carboxylesterase (CES). TAX-2'-Et did not exhibit polarized transport in the Caco-2 cells expressing P-glycoprotein (P-gp) in the absence or presence of verapamil which is a inhibitor of P-gp, suggesting that TAX-2'-Et is not a target of P-gp like TAX and rhodamine 123. Moreover, SKOV3/ TAX60 cells which are overexpressing P-gp did not also exhibit any change in cellular uptake of TAX-2'-Et regardless of the absence or presence of verapamil. Consequently, the uptake of TAX-2'-Et into the TAX-resistant cells was quantitatively similar to that internalized in the parental SKOV3 cells which are P-gp-negative. In the CES-transfected SKOV3 cells, the EC50 value of TAX (10.6 nM) was approximately 4-fold higher than that of TAX-2'-Et (2.5 nM). We herein provide evidence that TAX-2'-Et could circumvent P-gp-associated cellular efflux of TAX, suggesting that this combination therapy is a potential GDEPT strategy for ovarian cancer in the future. Finally, this review focuses on the development, application and potential of various GDEPTs for treating ovarian cancer, and the scope and progress of new GDEPTs are discussed.
  • Gene directed enzyme prodrug therapy for ovarian cancer: Could GDEPT become a promising treatment against ovarian cancer?, Akihiro Nawa, Tadatoshi Tanino, ChenHong Luo, Masahiro Iwaki, Hiroaki Kajiyama, Kiyosumi Shibata, Eiko Yamamoto, Kazuhiko Ino, Yukihiro Nishiyama, Fumitaka Kikkawa, ANTI-CANCER AGENTS IN MEDICINAL CHEMISTRY, ANTI-CANCER AGENTS IN MEDICINAL CHEMISTRY, 8(2), 232 - 239, Feb. 2008
    Summary:Gene-directed enzyme prodrug therapy (GDEPT) involves the treatment concept of having maximal efficacy and minimal adverse effects. Several GDEPT strategies have been developed combining cytosine deaminase and 5-fluorocytosine, cytochrome P450 2B1 and cyclophosphamide, and carboxylesterase (CES) and irinotecan in experimental models. The active forms of these prodrugs, however, are not a frontline therapy for the treatment of ovarian cancer. It would be beneficial to develop a more effective prodrugenzyme combination for the treatment of this disease. Paclitaxel (Taxol(R); TAX) is currently one of the most important anti-cancer drugs in chemotherapy of ovarian cancer. One of TAX prodrugs, 2'-ethylcarbonate-linked paclitaxel (TAX-2'-Et), was generated and examined regarding its pharmacological aspects. The prodrug of TAX-2'-Et converts into active form TAX by carboxylesterase (CES). TAX-2'-Et did not exhibit polarized transport in the Caco-2 cells expressing P-glycoprotein (P-gp) in the absence or presence of verapamil which is a inhibitor of P-gp, suggesting that TAX-2'-Et is not a target of P-gp like TAX and rhodamine 123. Moreover, SKOV3/ TAX60 cells which are overexpressing P-gp did not also exhibit any change in cellular uptake of TAX-2'-Et regardless of the absence or presence of verapamil. Consequently, the uptake of TAX-2'-Et into the TAX-resistant cells was quantitatively similar to that internalized in the parental SKOV3 cells which are P-gp-negative. In the CES-transfected SKOV3 cells, the EC50 value of TAX (10.6 nM) was approximately 4-fold higher than that of TAX-2'-Et (2.5 nM). We herein provide evidence that TAX-2'-Et could circumvent P-gp-associated cellular efflux of TAX, suggesting that this combination therapy is a potential GDEPT strategy for ovarian cancer in the future. Finally, this review focuses on the development, application and potential of various GDEPTs for treating ovarian cancer, and the scope and progress of new GDEPTs are discussed.
  • ALTERATION ON THE MRNA EXPRESSION OF ABC AND SLC TRANSPORTERS IN LIVER AND INTESTINE OF ADJUVANT-INDUCED ARTHRITIS RAT, Masahiro Iwaki, Satoshi Uno, Atsushi Kawase, DRUG METABOLISM REVIEWS, DRUG METABOLISM REVIEWS, 40, 213 - 214, 2008 , Refereed
  • Prediction of metabolic clearance of diclofenac in adjuvant-induced arthritis rats using a substrate depletion assay, S. Uno, A. Fujii, H. Komura, A. Kawase, M. Iwaki, XENOBIOTICA, XENOBIOTICA, 38(5), 482 - 495, 2008
    Summary:1.The purpose of this study was to evaluate drug clearance measured by the metabolic intrinsic clearance (CLint) in a substrate depletion assay in comparison with the in vivo clearance (CLtot) observed in adjuvant-induced arthritis (AA) rats. 2. After intravenous administration of diclofenac as a model drug, CLtot was 2.8-fold higher in AA rats than in control rats. In two different substrate depletion assays with liver microsomes for glucuronidation and hydroxylation, the CLint values for glucuronidation was significantly decreased in AA rats to 60% of the value in control rats, whereas the CLint values for hydroxylation were similar. The unbound fraction of diclofenac in plasma (fu, plasma) was significantly higher (2.8-fold) in AA rats than in control rats. 3. Hepatic clearance predicted from the CLint values for both biotransformation pathways and fu, plasma was higher in AA rats than in control rats, with good consistency between predicted and observed values. The same results were obtained for experiments using hepatocytes. 4. The plasma protein-binding activities, rather than metabolic clearance, in both types of rats would be a determining factor in the pharmacokinetic behaviour differences between control and AA rats. 5. In summary, substrate depletion assays with liver microsomes and hepatocytes in combination with protein binding assessment can help to predict changes in pharmacokinetics under AA conditions.
  • Impaired intrinsic chiral inversion activity of ibuprofen in rats with adjuvant-induced arthritis, S. Uno, M. Uraki, H. Komura, H. Ikuta, A. Kawase, M. Iwaki, XENOBIOTICA, XENOBIOTICA, 38(11), 1410 - 1421, 2008
    Summary:1. The effects of adjuvant-induced arthritis on the chiral inversion of 'profens', a type of non-steroidal anti-inflammatory drug, have hardly been investigated. The authors investigated the effects of adjuvant-induced arthritis on the chiral inversion of ibuprofen using freshly isolated rat hepatocytes. 2. S- or R-ibuprofen was incubated with hepatocytes isolated from control and adjuvant-induced arthritis rats in the absence of the serum. In the hepatocyte system the chiral inversion rate constant of R- to S-ibuprofen and the metabolic rate constants of both enantiomers in adjuvant-induced arthritis rats were significantly decreased to about 64-80% of the corresponding values in control rats. In contrast, the addition of serum from each group to the corresponding hepatocyte medium resulted in no significant differences in these rate constants between control and adjuvant-induced arthritis rats. 3. With regard to chiral inversion enzymes, adjuvant-induced arthritis decreased the messenger RNA levels of acyl-coenzyme A synthetase (ACS) isoforms, but not 2-arylpropionyl-CoA epimerase, compared with control rats. 4. Chiral inversion of R- to S-ibuprofen was inhibited by triacsin C, a specific inhibitor of ACS1. 5. The results suggest that adjuvant-induced arthritis induces down-regulation of ACS enzymes involved in chiral inversion of R- to S-ibuprofen in rats.
  • Differences in Cytochrome P450 and Nuclear Receptor mRNA Levels in Liver and Small Intestines between SD and DA Rats, Atsushi Kawase, Akiyuki Fujii, Makiko Negoro, Ryosuke Akai, Miki Ishikubo, Hiroshi Komura, Masahiro Iwaki, DRUG METABOLISM AND PHARMACOKINETICS, DRUG METABOLISM AND PHARMACOKINETICS, 23(3), 196 - 206, 2008 , Refereed
    Summary:This study aimed to clarify the differences in mRNA levels of cytochrome P450 (CYP) isoforms and nuclear receptors between Dark Agouti (DA) and Sprague-Dawley (SD) rats which are animal models for poor metabolizers and extensive metabolizers for CYP2D6, respectively. Using liver and small intestine tissues of both rat strains, we investigated the mRNA levels of CYP1A, 2A, 2B, 2C, 2D, 2E, and 3A subfamilies and nuclear receptors which regulate the transcription of CYP isoforms. In the liver, male DA rats showed a low CYP2D2 mRNA level but high mRNA levels of CYP3A1, 3A2, and 1A1 compared to SD rats. No significant difference was noted in other CYP isoforms. The mRNA levels of CAR were higher in DA rats than those in SD rats. In small intestine, the mRNA levels of CYP isoforms and nuclear receptors exhibited no significant strain differences. In addition, the activity of CYP3A in small intestinal microsome did not differ between SD and DA rats. Female DA rats exhibited higher mRNA levels of CYP3A1, 3A2, and 2B1 in the liver than female SD rats. In conclusion, the mRNA levels of CYP3A1 and 3A2 isoforms and CAR in the liver but not in the small intestines were different between DA and SD rats in both sexes.
  • Gum arabic enhances intestinal calcium absorption in rats, Atsushi Kawase, Noriko Hirata, Masashi Tokunaga, Hideaki Matsuda, Masahiro Iwaki, JOURNAL OF HEALTH SCIENCE, JOURNAL OF HEALTH SCIENCE, 53(5), 622 - 624, Oct. 2007
    Summary:We investigated whether the efficiency of intestinal calcium (Ca) absorption was improved by concomitant ingestion of gum arabic (GA) in rats. We used the Ussing chamber method to clarify the effect of GA on upper and lower small intestinal absorption of Ca. Increased in vitro Ca permeation was observed in rats who ingested water with 7.5% GA for 10 days. These results suggested that administration of GA with Ca could increase the efficiency of oral Ca absorption.
  • Species difference in the inhibitory effect of nonsteroidal anti-inflammatory drugs on the uptake of methotrexate by human kidney slices, Yoshitane Nozaki, Hiroyuki Kusuhara, Tsunenori Kondo, Masahiro Iwaki, Yoshiyuki Shiroyanagi, Hideki Nakayama, Shigeru Horita, Hayakazu Nakazawa, Teruo Okano, Yuichi Sugiyama, JOURNAL OF PHARMACOLOGY AND EXPERIMENTAL THERAPEUTICS, JOURNAL OF PHARMACOLOGY AND EXPERIMENTAL THERAPEUTICS, 322(3), 1162 - 1170, Sep. 2007 , Refereed
    Summary:Simultaneous use of nonsteroidal anti-inflammatory drugs ( NSAIDs), probenecid, and other drugs has been reported to delay the plasma elimination of methotrexate in patients. Previously, we have reported that inhibition of the uptake process cannot explain such drug-drug interactions using rats. The present study quantitatively evaluated the possible role of the transporters in such drug-drug interactions using human kidney slices and membrane vesicles expressing human ATP-binding cassette (ABC) transporters. The uptake of methotrexate by human kidney slices was saturable with a K m of 45 to 49 mu M. Saturable uptake of methotrexate by human kidney slices was markedly inhibited by p-aminohippurate and benzylpenicillin, but only weakly by 5-methyltetrahydrofolate. These transport characteristics are similar to those of a basolateral organic anion transporter (OAT) 3/SLC22A8. NSAIDs and probenecid inhibited the uptake of methotrexate by human kidney and, in particular, salicylate, indomethacin, phenylbutazone, and probenecid were predicted to exhibit significant inhibition at clinically observed plasma concentrations. Among ABC transporters, such as BCRP/ABCG2, multidrug resistance-associated protein (MRP) 2/ABCC2, and MRP4/ABCC4, which are candidates for the luminal efflux of methotrexate, ATP-dependent uptake of methotrexate by MRP4-expressing membrane vesicles was most potently inhibited by NSAIDs. Salicylate and indomethacin were predicted to inhibit MRP4 at clinical plasma concentrations. Diclofenac-glucuronide significantly inhibited MRP2-mediated transport of methotrexate in a concentration-dependent manner, whereas naproxen-glucuronide had no effect. Inhibition of renal uptake (via OAT3) and efflux processes (via MRP2 and MRP4) explains the possible sites of drug-drug interaction for methotrexate with probenecid and some NSAIDs, including their glucuronides.
  • Species difference in the inhibitory effect of nonsteroidal anti-inflammatory drugs on the uptake of methotrexate by human kidney slices, Yoshitane Nozaki, Hiroyuki Kusuhara, Tsunenori Kondo, Masahiro Iwaki, Yoshiyuki Shiroyanagi, Hideki Nakayama, Shigeru Horita, Hayakazu Nakazawa, Teruo Okano, Yuichi Sugiyama, JOURNAL OF PHARMACOLOGY AND EXPERIMENTAL THERAPEUTICS, JOURNAL OF PHARMACOLOGY AND EXPERIMENTAL THERAPEUTICS, 322(3), 1162 - 1170, Sep. 2007
    Summary:Simultaneous use of nonsteroidal anti-inflammatory drugs ( NSAIDs), probenecid, and other drugs has been reported to delay the plasma elimination of methotrexate in patients. Previously, we have reported that inhibition of the uptake process cannot explain such drug-drug interactions using rats. The present study quantitatively evaluated the possible role of the transporters in such drug-drug interactions using human kidney slices and membrane vesicles expressing human ATP-binding cassette (ABC) transporters. The uptake of methotrexate by human kidney slices was saturable with a K m of 45 to 49 mu M. Saturable uptake of methotrexate by human kidney slices was markedly inhibited by p-aminohippurate and benzylpenicillin, but only weakly by 5-methyltetrahydrofolate. These transport characteristics are similar to those of a basolateral organic anion transporter (OAT) 3/SLC22A8. NSAIDs and probenecid inhibited the uptake of methotrexate by human kidney and, in particular, salicylate, indomethacin, phenylbutazone, and probenecid were predicted to exhibit significant inhibition at clinically observed plasma concentrations. Among ABC transporters, such as BCRP/ABCG2, multidrug resistance-associated protein (MRP) 2/ABCC2, and MRP4/ABCC4, which are candidates for the luminal efflux of methotrexate, ATP-dependent uptake of methotrexate by MRP4-expressing membrane vesicles was most potently inhibited by NSAIDs. Salicylate and indomethacin were predicted to inhibit MRP4 at clinical plasma concentrations. Diclofenac-glucuronide significantly inhibited MRP2-mediated transport of methotrexate in a concentration-dependent manner, whereas naproxen-glucuronide had no effect. Inhibition of renal uptake (via OAT3) and efflux processes (via MRP2 and MRP4) explains the possible sites of drug-drug interaction for methotrexate with probenecid and some NSAIDs, including their glucuronides.
  • Effects of alterations in CAR on bilirubin detoxification in mouse collagen-induced arthritis, Atsushi Kawase, You Tsunokuni, Masahiro Iwaki, DRUG METABOLISM AND DISPOSITION, DRUG METABOLISM AND DISPOSITION, 35(2), 256 - 261, Feb. 2007 , Refereed
    Summary:Nuclear receptors such as constitutive androstane receptor (CAR) and pregnane X receptor (PXR) regulate the transcription of cytochromes P450 and transporters. We investigated whether quantitative and functional changes in CAR and PXR could affect bilirubin detoxification in chronic arthritis. The CAR mRNA level was significantly decreased in the liver of mice with collagen-induced arthritis (CIA) compared with control mice. In normal mice treated with CAR agonists, relatively rapid elimination of bilirubin was observed after its intravenous injection. Next, we investigated the effects of CAR on bilirubin-detoxifying enzymes and transporters in arthritis. The mRNA levels of organic anion transporter peptide (OATP) 2, glutathione S-transferase (GST) A1, and GSTA2 were decreased in CIA mice, whereas the mRNA levels of OATP4, UDP-glucuronosyltransferase 1A1, and multidrug resistance-associated protein 2 remained unchanged. The protein levels and transport activities of OATP2 were also decreased in CIA mice. Furthermore, the CIA mice actually exhibited retarded elimination of bilirubin after its intravenous injection. These results indicate that alterations to CAR during arthritis affect the elimination of bilirubin because of changes in multiple bilirubin-detoxifying enzymes and transporters.
  • SPECIES DIFFERENCES IN SMALL INTESTINAL METABOLISM OF CYP3A4 SUBSTRATES, Hiroshi Komura, Hiroaki Takubo, Motohiro Kogayu, Masahiro Iwaki, DRUG METABOLISM REVIEWS, DRUG METABOLISM REVIEWS, 39, 108 - 108, 2007 , Refereed
  • Decreased intestinal CYP3A and p-glycoprotein activities in rats with adjuvant arthritis, Satoshi Uno, Atsushi Kawase, Akiko Tsuji, Tadatoshi Tanino, Masahiro Iwaki, DRUG METABOLISM AND PHARMACOKINETICS, DRUG METABOLISM AND PHARMACOKINETICS, 22(4), 313 - 321, 2007 , Refereed
    Summary:Adjuvant- induced arthritis (AA) rats have been used as an animal model for rheumatoid arthritis. Several studies have shown that the pharmacokinetics of a number of drugs are altered in AA rats. We investigated the effects of AA on the barrier functions of the intestine using a rat model. Intestinal CYP3A activities (midazolam 1'-hydroxylation and 7-benzyloxy-4-(trifluoromethyl)-coumarin 7-hydroxylation) in AA rats were significantly decreased compared with those in normal rats, with marked decrease observed in the upper segment of intestine. Intestinal P-glycoprotein (P-gp) activitiy at upper segment was also significantly decreased in AA rats to 60% of that in normal rats, and the other segments (middle and lower) of intestine also exhibited tendencies toward decrease in P-gp activity. This decrease was supported by the finding that levels of mdr1a mRNA and P-gp protein were decreased in AA rats. No significant diSerences were observed in intestinal paracellular and transcellular permeability between AA and normal rats. These results suggest that intestinal CYP3A and P-gp activities are decreased in AA rats, and that the pharmacokinetics and bioavailabilities of drugs whose membrane permeation is limited by intestinal CYP3A and/or P-gp may be altered in rheumatic diseases.
  • Decreased PXR and CAR inhibit transporter and CYP mRNA Levels in the liver and intestine of mice with collagen-induced arthritis, A. Kawase, I. Yoshida, Y. Tsunokuni, M. Iwaki, XENOBIOTICA, XENOBIOTICA, 37(4), 366 - 374, 2007
    Summary:Nuclear receptors, such as pregnane X receptor (PXR) and constitutive androstane receptor (CAR), regulate the transcription of transporters and cytochrome P450s (CYPs). We investigated whether quantitative and functional changes in PXR and CAR affected the transporters and CYPs in a mouse model of chronic arthritis. The mRNA levels of PXR were significantly decreased in the intestine of mice with collagen-induced arthritis (CIA) compared with control mice. The mRNA levels of CAR were significantly decreased in both the liver and intestine of CIA mice. The mRNA levels of Mdr1a/1b, Mrp3, BCRP and Cyp2b10 were decreased in the liver of CIA mice, while little change in the mRNA levels was observed for Cyp3a11 in the liver and the transporters in the intestine. Taken together, the present results reveal that the effects of CAR mRNA suppression on the regulation of transporters and CYPs differ between the liver and intestine in chronic arthritis.
  • Application of substrate depletion assay for early prediction of nonlinear pharmacokinetics in drug discovery: Assessment of nonlinearity of metoprolol, timolol, and propranolol, H Komura, A Kawase, M Iwaki, JOURNAL OF PHARMACEUTICAL SCIENCES, JOURNAL OF PHARMACEUTICAL SCIENCES, 94(12), 2656 - 2666, Dec. 2005 , Refereed
    Summary:The purpose of this study was to investigate the advantages of the substrate depletion assay for evaluating linearity of pharmacokinetics compared with the metabolite formation assay. For propranolol, metoprolol, and nisoldipine with multiple and/or sequential metabolisms, the Michaelis constant (K-m) and maximum metabolic intrinsic clearance obtained from the depletion assay using rat and human liver microsomes showed a good correlation with relevant parameters with the formation assay. In vitro kinetics and in vivo pharmacokinetic profiles after oral administration of timolol, metoprolol, and propranolol, were investigated in rats using the depletion assay. The same rank order was found between nonlinearities based on dose-normalized areas under the plasma concentration curve (AUC/Dose) and K-m values. Using the kinetic parameters of these compounds, AUC was predicted based on a physiological based pharmacokinetic model incorporated saturable metabolism. The AUCs predicted for propranolol and metoprolol had a good relationship with those observed in the in vivo studies, implying that the depletion assay could be useful for assessing linearity of pharmacokinetics. (c) 2005 Wiley-Liss, Inc. and the American Pharmacists Association.
  • Usefulness of hepatocytes for evaluating the genetic polymorphism of CYP2D6 substrates, H Komura, M Iwaki, XENOBIOTICA, XENOBIOTICA, 35(6), 575 - 587, Jun. 2005
    Summary:The usefulness of human hepatocytes for assessing CYP2D6-related genetic polymorphisms was investigated. Propranolol and propafenone, which undergo phase I and II biotransformations, were used as model substrates alongside metoprolol, which is only metabolized via oxidative pathways. The contributions of CYP2D6 to the primary metabolisms of the substrates were estimated from the quinidine-mediated inhibition of their depletion rate constants in human hepatocytes and liver microsomes. The contributions in hepatocytes were 19.2% for propranolol at 0.05 mu M and 36.7 - 76.3% for propafenone at 0.05 - 1.0 mu M, and smaller than the contribution in microsomes, unlike the case for metoprolol. The differences between microsomes and hepatocytes were attributable to conjugate formation. The CYP2D6 contributions in hepatocytes reflected the in vivo data. The relevance of the concentration-dependent involvement of CYP2D6 in propafenone metabolism in hepatocytes to the in vivo polymorphic profile and the applicability of hepatocytes for evaluating these polymorphisms are discussed.
  • Nonlinear pharmacokinetics of propafenone in rats and humans: Application of a substrate depletion assay using hepatocytes for assessment of nonlinearity, H Komura, M Iwaki, DRUG METABOLISM AND DISPOSITION, DRUG METABOLISM AND DISPOSITION, 33(6), 726 - 732, Jun. 2005 , Refereed
    Summary:Linear pharmacokinetic profiles of propafenone in female Wistar rats were found after oral administration of up to 20 mg/kg. These profiles differed from nonlinear pharmacokinetics in a dose-dependent manner with increasing plasma concentrations in humans ( Hollmann M, Brode E, Hotz D, Kaumeier S, and Kehrhahn OH ( 1983) Arzneim-Forsch 33: 763 - 770). We investigated the species differences in pharmacokinetics of propafenone between rats and humans. In rats, after intravenous administration, clearance was constant at all doses examined (0.2 - 10 mg/kg), whereas the distribution volume at a steady state increased and the resultant elimination half-life was prolonged with increasing doses. In a substrate depletion assay without plasma, rat and human hepatocytes showed a concentration-dependent elimination of propafenone with low K-m values (< 0.4 μ M). However, in the depletion assay with plasma incubation, the profiles were altered to a concentration-independent profile in rat but not human hepatocytes. The differing effect of adding plasma in rat and human hepatocytes can be explained by species differences in plasma binding (unbound fraction, 0.0071 versus 0.0754 for rats and humans, respectively, at 0.1 μ g/ml). In rat plasma, the unbound fraction increased with concentrations of 0.1 to 1.0 μ g/ml, whereas it was constant in human plasma. Accordingly, the in vivo nonlinear disposition in humans can be ascribed to the saturation of hepatic metabolism due to the low Km values. In contrast, the influence of saturable metabolism is canceled out with nonlinear plasma binding in rats leading to the apparent linear pharmacokinetic behavior. The newly developed depletion assay with plasma incubation gave insights into the nonlinear pharmacokinetics of propafenone.
  • Pharmacokinetics and metabolism of metoprolol and propranolol in the female DA and female Wistar rat: The female DA rat is not always an animal model for poor metabolizers of CYP2D6, H Komura, M Iwaki, JOURNAL OF PHARMACEUTICAL SCIENCES, JOURNAL OF PHARMACEUTICAL SCIENCES, 94(2), 397 - 408, Feb. 2005
    Summary:The purpose of this study was to clarify the pharmacokinetics of GYP2D6 substrates in female DA and Wistar rats, which are regarded as animal models of poor metabolizers and extensive metabolizers, respectively. In vivo pharmacokinetic and in vitro metabolic studies were conducted using metoprolol and propranolol,which show substantial and marginal polymorphisms in humans, respectively. After oral administration, the areas under the plasma concentration curves (AUC) for metoprolol and propranolol in DA rats were ca. 5- and 35-fold higher, respectively, than those in Wistar rats. There were no strain differences for serum protein binding or metabolism inhibition by quinine between the two compounds. Using a substrate depletion assay, the intrinsic clearances estimated for the two strains differed by 7.2-fold for metoprolol and 4.5-fold for propranolol. The discrepancy between the in, vitro and in. vivo profiles observed for propranolol, but not metoprolol, would be due to nonlinearity between the normalized AUC and the oral doses in DA rats, being associated with lower K, values. The larger strain difference in the AUCs of propranolol was proved by the in vitro kinetic parameters, implying that DA rats do not always reflect the polymorphic profiles in humans. (C) 2004 Wiley-Liss, Inc. and the American Pharmacists Association.
  • Mevastatin induces apoptosis in HL60 cells dependently on decrease in phosphorylated ERK, S Nishida, H Matsuoka, M Tsubaki, Y Tanimori, M Yanae, Y Fujii, M Iwaki, MOLECULAR AND CELLULAR BIOCHEMISTRY, MOLECULAR AND CELLULAR BIOCHEMISTRY, 269(1-2), 109 - 114, Jan. 2005 , Refereed
    Summary:Mevastatin which is an inhibitor of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, the rate-limiting enzyme in cholesterol synthesis, suppress cell proliferation and induce apoptosis. However, the molecular mechanism of apoptosis induction is not well understood. So, in the present study, we attempted to clarify the mechanism by which mevastatin induces apoptosis in HL60 cells. It was found that mevastatin induced apoptosis. At that time, we observed an increase in caspase-3 activity and morphological fragmentation of the nuclei. The apoptosis induced by mevastatin was not inhibited by the addition of farnesyl pyrophosphate (FPP), squalene, ubiquinone, and isopentenyladenine, but was inhibited by the addition of geranylgeranyl pyrophosphate (GGPP). When we examined the survival signals at the time of apoptotic induction, we also observed that the administration of mevastatin had caused a remarkable decrease in the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2). However, other survival signals, such as nuclear factor kappa B (NF-kappaB), protein kinase B (Akt), and p38 mitogen-activated protein kinase (p38), exhibited no change. In addition, no quantitative change was observed in Bcl-2, which was an anti-apoptosis protein. It was also observed that apoptosis was induced when U0126, an MEK inhibitor, was added to the cells to inhibit ERK. These results suggested that mevastatin induced apoptosis when it inhibited GGPP biosynthesis and consequently decreased the level of phosphorylated ERK, which was a survival signal; moreover, at that time, there was no influence on NF-kappaB, Akt, p38, and Bcl-2. The results of this study also suggested that mevastatin could be used as an anticancer agent.
  • Potent and metabolically stable agonists for protease-activated receptor-2: Evaluation of activity in multiple assay systems in vitro and in vivo, A Kawabata, T Kanke, D Yonezawa, T Ishiki, M Saka, M Kabeya, F Sekiguchi, S Kubo, R Kuroda, M Iwaki, K Katsura, R Plevin, JOURNAL OF PHARMACOLOGY AND EXPERIMENTAL THERAPEUTICS, JOURNAL OF PHARMACOLOGY AND EXPERIMENTAL THERAPEUTICS, 309(3), 1098 - 1107, Jun. 2004
    Summary:To develop potent and metabolically stable agonists for protease-activated receptor-2 (PAR-2), we prepared 2-furoylated (2f) derivatives of native PAR-2-activating peptides, 2f-LIGKV-OH, 2f-LIGRL-OH, 2f-LIGKV-NH2, and 2f-LIGRL-NH2, and systematically evaluated their activity in PAR-2-responsive cell lines and tissues. In both HCT-15 cells and NCTC2544 cells overexpressing PAR-2, all furoylated peptides increased cytosolic Ca2+ levels with a greater potency than the corresponding native peptides, although a similar maximum response was recorded. The absolute potency of each peptide was greater in NCTC2544, possibly due to a higher level of receptor expression. Furthermore, the difference in potency between the 2-furoylated peptides and the native peptides was enhanced when evaluated in the rat superior mesenteric artery and further increased when measuring PAR-2-mediated salivation in ddY mice in vivo. The potency of 2f-LIGRL-NH2, the most powerful peptide, relative to SLIGKV-OH, was about 100 in the cultured cell Ca2+ signaling assays, 517 in the vasorelaxation assay, and 1100 in the salivation assay. Amastatin, an aminopeptidase inhibitor, augmented salivation caused by native peptides, but not furoylated peptides. The PAR-2-activating peptides, including the furoylated derivatives, also produced salivation in the wild-type C57BL/6 mice, but not the PAR-2-deficient mice. Our data thus demonstrate that substitution of the N-terminal serine with a furoyl group in native PAR-2-activating peptides dramatically enhances the agonistic activity and decreases degradation by aminopeptidase, leading to development of 2f-LIGRL-NH2, the most potent peptide. Furthermore, the data from PAR-2-deficient mice provide ultimate evidence for involvement of PAR-2 in salivation and the selective nature of the 2-furoylated peptides.
  • Stereoselective pharmacokinetics of flurbiprofen and formation of covalent adducts with plasma protein in adjuvant-induced arthritic rats, T Nagao, T Tanino, M Iwaki, CHIRALITY, CHIRALITY, 15(5), 423 - 428, May 2003 , Refereed
    Summary:To determine the effect of arthritis on the disposition of flurbiprofen (FP) and its acyl glucuronide (FPG) as well as formation of covalent adducts with plasma protein, a pharmacokinetic study was carried out in adjuvant-induced arthritic (AA) rats. In control animals the pharmacokinetics of FP were stereoselective following intravenous bolus injection of rae-FP: (-)-(R)-FP showed higher plasma clearance (CLtot) and shorter mean residence time (MRT) compared to (+)-(S)-FP. The CLtot and clearance for the glucuronide formation (CLglu) of both enantiomers in AA rats were extremely increased compared to those in control rats. Increased total clearance in AA rats was due, at least in part, to a remarkable increase in the plasma unbound fraction of FP, consistent with a decrease in the plasma albumin level. The yield of covalent binding of FP to plasma protein in AA rats was less than that in controls, being consistent with the decrease in the plasma acyl glucuronide level.
  • Transfollicular drug delivery: Penetration of drugs through human scalp skin and comparison of penetration between scalp and abdominal skins in vitro, T Ogiso, T Shiraki, K Okajima, T Tanino, M Iwaki, T Wada, JOURNAL OF DRUG TARGETING, JOURNAL OF DRUG TARGETING, 10(5), 369 - 378, Aug. 2002 , Refereed
    Summary:In order to quantitatively investigate the importance of transfollicular pathway for drug delivery, drug penetration through human scalp skin was investigated using liquid formulations containing lipophilic and hydrophilic drugs in vitro. The penetration pathway for drugs through the scalp skin was examined using fluorescent probes, Additionally, the drug penetration through the scalp skin was compared with that via human abdominal skin to clarify the usefulness of intrafollicular delivery. Lipophilic melatonin (MT) and ketoprofen (KP) showed high permeabilities through the scalp skin, although the flux of KP was much higher. Absorption enhancers, N-methyl-2-pyrrolidone and isopropylmyristate, only slightly increased the fluxes. Hydrophilic fluorouracil (5FU) and acyclovir (ACV) penetrated through the scalp skin with relatively large fluxes. However, there was large variability in the fluxes of these drugs across scalp skin from different sources. When the relationship between the flux and hair follicle density was estimated, there was good correlation between the two (r = 0.651 for MT and r = 0.666 for ACV, P < 0.05). The histologic examination of the scalp skin, following application of the formulation with nile red or sodium fluorescein, indicated that the probes permeated into the junction of the internal and external root sheath of follicles and diffused into the dermis via the outer root sheath at the initial times. The penetration of nile red, a lipophilic probe, via the stratum corneum of scalp skin was later than that via the follicles. The permeation of MT and 5FU through the scalp skin was much higher than that via the abdominal skin, being 27 and 48 times as high as the abdominal skin, respectively. These results indicate that the drug delivery through the scalp skin will offer an available delivery means for drugs, particularly for hydrophilic drugs.
  • Pharmacokinetics of epinastine and a possible mechanism for double peaks in oral plasma concentration profiles, T Ogiso, M Kasutani, H Tanaka, M Iwaki, T Tanino, BIOLOGICAL & PHARMACEUTICAL BULLETIN, BIOLOGICAL & PHARMACEUTICAL BULLETIN, 24(7), 790 - 794, Jul. 2001
    Summary:The pharmacokinetics of epinastine (EPN), an anti-allergic agent, was investigated in rats. The plasma concentration-time profile of EPN after intravenous (i.v.) administration was triexponential. After oral administration of EPN (7.5 and 20 mg/kg), the drug was rapidly absorbed, and C-max was reached 2 h after dosing. A minor secondary peak was observed in EPN plasma concentration-time profiles at both doses. The bioavailability of EPN after oral dosing was 41 and 40%, The kinetic parameters (T-1/2, AUC and MRT) for unlabeled EPN were much smaller than those for C-14-EPN, which has already been reported. The total biliary excretion of EPN at a 7.5 mg/kg dose was 15.5% of the dose, but the percentage of conjugates in bile was extremely low and about 11% of the total biliary excretion. The increase in the plasma concentration in bile duct-linked rats after oral administration of EPN (20 mg/kg) was not observed, indicating that a secondary increase in drug concentration based on enterohepatic circulation was ruled out. When the gastrointestinal (GI)-transit of phenol red (PR) after oral administration of EPN (20 mg/kg) was estimated, the GI-transit of PR was significantly delayed, and at 3-4 h after dosing half of the PR dose reached the jejunum, The remaining EPN in the small intestine after oral administration (7.5 mg/kg) reached peak levels 2 h after dosing, but then partly increased again at 4 h, As a result, it was clarified that the double peaks observed after oral doses are mainly due to the delayed absorption of a part of EPN. based on the reduction in gastric motility caused by the drug.
  • Oral delivery of synthetic eel calcitonin, elcatonin, in rats, T Ogiso, N Funahashi, Y Tsukioka, M Iwaki, T Tanino, T Wada, BIOLOGICAL & PHARMACEUTICAL BULLETIN, BIOLOGICAL & PHARMACEUTICAL BULLETIN, 24(6), 656 - 661, Jun. 2001
    Summary:This study was designed to develop an oral dosage form of elcatonin (EC), a hypocalcemic peptide. The EC absorption was estimated by the reduction in plasma calcium concentrations. When EC was orally coadministered with nitroso-N-acetyl-D,L-penicillamine (SNAP, 4.0 mg) and 0.02% Carbopol solution or with taurocholate (20 mM) and 0.02% Carbopol solution, the lowering effect was increased compared with that after EC alone, but the F values (0.32 and 0.30%) were extremely small. The oral administration of the mucoadhesive emulsion, which was prepared by coating the W/O/W emulsion with 0.1% Carbopol, enhanced the calcium lowering effect, with the F value of 0.43%, The strong mucoadhesion of the mucoadhesive emulsion to the gastrointestinal mucosa was observed. A capsule containing EC (500 mug), taurocholate (6 mg) and lyophilized Carbopol (3.5 mg) administered orally gave a sustained but comparatively small calcium lowering effect, In the in vitro enzymatic hydrolysis experiment, EC was more rapidly hydrolyzed in the intestinal fluid than in the mucosal extract, The combination of 20 mM taurocholate with 0.02% Carbopol showed the greatest inhibitory effect in both fluid and extract. These data indicated that EC was effectively absorbed through the intestinal wall, but the peptide was dominantly degraded by proteolytic: enzymes in the GI tract. These results will offer a potential approach to the oral delivery of EC.
  • Capillary electrophoresis of sialic acid-containing glycoprotein. Effect of the heterogeneity of carbohydrate chains on glycoform separation using an alpha(1)-acid glycoprotein as a model, K Kakehi, M Kinoshita, D Kawakami, J Tanaka, K Sei, K Endo, Y Oda, M Iwaki, T Masuko, ANALYTICAL CHEMISTRY, ANALYTICAL CHEMISTRY, 73(11), 2640 - 2647, Jun. 2001
    Summary:alpha (1)-Acid glycoprotein (AGP) showed multiple peaks on separation using capillary electrophoresis in a chemically modified capillary dth dimethylpolysiloxane at slightly acidic conditions. We analyzed glycoforms of AGP species after separation by ion-exchange chromatography Con A affinity chromatography, and Cu(II)-chelating affinity chromatography. The AGP species thus obtained were digested with N-glycosidase F, and the released carbohydrate chains were analyzed by high-performance liquid chromatography after labeling with 3-aminobenzoic acid. The results afforded basic information on the contribution of carbohydrate chains to the separation mechanism of glycoforms of AGP by capillary electrophoresis, In addition, we describe an easy method for AGP analysis in serum samples using the electrokinetic injection.
  • Transdermal absorption of bupranolol in rabbit skin in vitro and in vivo, T Ogiso, T Hata, M Iwaki, T Tanino, BIOLOGICAL & PHARMACEUTICAL BULLETIN, BIOLOGICAL & PHARMACEUTICAL BULLETIN, 24(5), 588 - 591, May 2001
    Summary:This study was designed to clarify the percutaneous penetration of bupranolol (BP), a beta -adrenoceptor antagonist, through rabbit skin and to compare the in vitro penetration with the in vivo absorption. BP penetrated across the skin slowly in the absence of enhancers in vitro. Isopropyl myristate and N-methyl-2-pyrrolidone enhanced the in vitro penetration, with a 3.6 times higher flux compared with that without enhancers. However, in the in vivo percutaneous absorption, the maximal penetration was obtained with the formulation added d-limonene, with a 3.0 times higher area under the concentration-time curve (AUC) than that for the formulation without enhancers. The plasma levels of BP determined, however, were extremely lower than the theoretical plasma steady-state concentrations predicted. The plasma levels of BF after application of these formulations were maintained in the range of 7-22 ng/ml for 30 h, of a which concentrations were above the therapeutically effective concentration (1.5-4 ng/ml). Therefore, the transdermal systems will offer an efficient drug delivery system for the treatment of angina pectoris and tachycardia.
  • Pharmacokinetics of Aniracetam and Its Metabolites in Rat Brain, Taro OGISO, Kaori UCHIYAMA, Hiroko SUZUKI, Mika YOSHIMOTO, Tadatoshi TANINO, Masahiro IWAKI, Satoshi UNO, Biol. Pharm. Bull., Biol. Pharm. Bull., 23(4), 482 - 486, 2000
  • Pharmacokinetics Drug Interactions between Ampiroxicam and Sulfaphenazole in Rats, Taro OGISO, Masahiro IWAKI, Hiroaki TANAKA, Eri KOBAYASHI, Tadatoshi TANINO, Arisa SAWADA, Satoshi UNO, Biol. Pharm. Bull., Biol. Pharm. Bull., 22(2), 191 - 196, 1999
  • In vitro regioselective stability of β-1-O-and 2-O-acyl glucuronides of naproxen and their covalent binding to human serum albumin, J. Pharm. Sci., J. Pharm. Sci., 88(1), 52 - 57, 1999
  • Pharmacokinetics of aniracetam and its metabolites in rats, J. Pharm. Sci., J. Pharm. Sci., 87(5), 594 - 598, 1998
  • Simultaneous determination of nicotinic acid and its metabolites in rat urine by micellar electrokinetic chromatography with photodiode aray detection, J. Chromatogr-B, J. Chromatogr-B, 716(1/2), 335 - 342, 1998
  • Mechanism for enbancement effect of lipid disperse system on percutaneous absorption Part II, Int. J. Pharm., Int. J. Pharm., 152(2), 135 - 144, 1997
  • In vitro skin penetration and degradation of enkephalin, elcatonin and insulin, Biol. Pharm. Bull., Biol. Pharm. Bull., 20(1), 54 - 60, 1997
  • Pharmacokinetic Analysis of Enterohepatic Circulation of Etodolac and Effect of Hepatic and Renal Injury on the Pharmacokintics, Biol. Pharm. Bull., Biol. Pharm. Bull., 20(4), 405 - 410, 1997
  • Acute dose-dependent Disposition of Nicotinic Acid in Rats, Drug metabolism and disposition, Drug metabolism and disposition, 24(4), 779 - 1103, 1996
  • Stereoselective binding properties of naproxen glucuronide diastereomers to proteins, A Bischer, P ZiaAmirhosseini, M Iwaki, AF McDonagh, LZ Benet, JOURNAL OF PHARMACOKINETICS AND BIOPHARMACEUTICS, JOURNAL OF PHARMACOKINETICS AND BIOPHARMACEUTICS, 23(4), 379 - 395, Aug. 1995
    Summary:The stability of naproxen glucuronide (NAP-G) diastereomers was investigated in buffer, 0.3% and 3% human serum albumin (HSA) solutions, and human plasma. R-NAP-G was found to be les stable in phosphate buffer than its S-diastereomer, whereas incubation media containing protein in general increased the degradation rate of NAP-G but also caused a change of the stereoselective stability where the R-NAP-G was more stable than S-NAP-G. Reversible binding of NAP-Gs to HSA (0.3%) was investigated and compared with the corresponding properties of naproxen (NAP) enantiomers. NAP-G diastereomers exibited a considerable and stereoselective affinity to HSA, although less than that observed for the NAP enantiomers. In vitro irreversible binding of NAP-Gs to HSA, human and rat plasma proteins was also investigated. Irreversible binding was higher for R-NAP-G (50 mu M) than for S-NAP-G (50 mu M) in all incubation media. This stereoselective difference was observed with HSA containing medium as well as in rat and human plasma. Incubation with unconjugated NAP did not lead to irreversible binding. Preincubation of HSA with acetylsalicylic acid (similar to 11 mM) and glucuronic acid (50 mM) decreased the extent of irreversible binding suggesting involvement of lysine residues for covalent binding. Preincubation with S-NAP also decreased the irreversible binding yield. (C) 1995 Plenum Publishing Corporation
  • Stereoselective Reversible Binding Properties of the Glucuronide Conjugates of Fenoprofen Enantiomers to Human Serum Albumin, Drug Metabolism and Disposition, Drug Metabolism and Disposition, 23, 1995
  • Percutaneous Absorption of Betahistine through Rat Skin and Pharmacokinetic Analysis of the Plasma Concentration, Int. J. Pharm., Int. J. Pharm., 102(1/3), 141 - 149, 1994
  • PHARMACOKINETICS OF INDOMETHACIN OCTYL ESTER (PRODRUG) AND INDOMETHACIN PRODUCED FROM THE PRODRUG, T OGISO, M IWAKI, T KINOSHITA, T TANINO, T PAKU, JOURNAL OF PHARMACEUTICAL SCIENCES, JOURNAL OF PHARMACEUTICAL SCIENCES, 83(1), 34 - 37, Jan. 1994
    Summary:A prodrug of indomethacin, indomethacin octyl ester (IM-OE), was synthesized and its pharmacokinetics was investigated in rat. To describe the time course of the plasma indomethacin and IM-OE after intravenous (iv) and oral administrations, a pharmacokinetic model with four compartments was developed. Indomethacin rapidly appeared in plasma after iv administration of IM-OE and declined in a monoexponential manner, with a rapid decline and low plasma levels of IM-OE. The plasma concentrations of indomethacin after oral administration of IM-OE were much lower than those after oral administration of indomethacin. The high concentrations of IM-OE compared with indomethacin were detected in liver 3 h after oral dosing of the prodrug, although IM-OE was not detected in plasma. A good fit was obtained between the observed and calculated curves based on the model, which includes a conversion rate constant of IM-OE to indomethacin for both iv and oral dosings of IM-OE. Additionally, the model could successfully describe the plasma concentration versus time profiles after indomethacin dosings.
  • Simultaneous Measurement of Nicotinic Acid and Its Major Metabolite, Nicotinuric Acid in Urine Using High-performance Liquid Chromatography : Application of Solid-Liquid Extraction, Journal of Chromatography, Journal of Chromatography, 661(1), 154 - 158, 1994
  • PHARMACOKINETICS OF CYPROHEPTADINE AND ITS METABOLITES IN RATS, M IWAKI, T OGISO, Y FUJII, T TANINO, Y ITO, Y MIKI, BIOLOGICAL & PHARMACEUTICAL BULLETIN, BIOLOGICAL & PHARMACEUTICAL BULLETIN, 16(12), 1276 - 1281, Dec. 1993
    Summary:To investigate the pharmacokinetics of cyproheptadine (CPH) and its metabolites, the plasma concentration and urinary excretion of CPH and its detectable metabolites were determined after intravenous (i.v.) administration of parent or synthesized metabolites to rats. The plasma CPH concentration-time course was subjected to biexponential calculation following the i.v. administration of CPH, producing the temporal and low plasma concentrations of desmethylcyproheptadine (DMCPH) and the sustained plasma concentrations of desmethylcyproheptadine-epoxide (DMCPHepo). DMCPH was also eliminated, according to the biexponenital equation, after i.v. administration of preformed DMCPH, forming DMCPHepo in plasma. On the other hand, no detectable DMCPHepo was found in plasma after the i.v. administration of cyproheptadine epoxide (CPHepo). All compounds administered had large distribution volumes and were almost entirely excreted as DMCPHepo in urine; this excretion continued for a long time. However, the urinary excretion pattern of DMCPHepo after CPHepo was different from those after CPH and DMCPH. The mean residence times of the epoxidized metabolites estimated from the urinary data were much longer than those from the plasma concentration data, suggesting either a gradual reflux of the metabolites from a tissue depot into systemic circulation under those plasma concentrations close of detection limit, or some interaction which delays excretion into the urine. This study suggests that both metabolic pathways of CPH, through DMCPH and CPHepo, to DMCPHepo are possible, but that the demethylation of CPH largely occurs prior to epoxidation; also that the extensive and persistent distribution of DMCPHepo to tissues may relate to the toxicity of CPH reported in rats.
  • PHARMACOKINETIC ANALYSIS OF PHENYTOIN AND ITS DERIVATIVES IN PLASMA AND BRAIN IN RATS, T OGISO, M IWAKI, T TANINO, O MURAOKA, G TANABE, BIOLOGICAL & PHARMACEUTICAL BULLETIN, BIOLOGICAL & PHARMACEUTICAL BULLETIN, 16(10), 1025 - 1030, Oct. 1993
    Summary:The derivatives of phenytoin (DPH) were synthesized by the reaction at 3 position of hydantoin ring with valproic acid and valeric acid, producing valproyl DPH (VPDPH) and valeroyl DPH (VADPH), respectively. These derivatives showed much higher lipid solubilities than that of DPH. Their distribution and elimination were compared to those of DPH. Additionally, the concentration profiles of the drugs in brain and plasma were analyzed with a modified 2-compartment model. DPH and its derivatives, without hydrolysis to DPH in blood, were found rapidly distributed into brain, although the distribution of derivatives was much less, probably due to the high protein binding capacities. The distribution of DPH and its derivatives into brain regions was similar to that into the cortex cerebri. VPDPH and VADPH were more rapidly eliminated from plasma and brain than DPH, giving smaller mean residence time (MRT) values (0.92 and 0.85 h) and much smaller cortex/plasma concentration ratio than those of DPH. The VPDPH and VADPH concentrations in the cerebrospinal fluid (CSF) were also much lower than that of DPH. The time course of plasma and brain concentrations of DPH and its derivatives after i.v. administration was successfully described by the modified 2-compartment models presented.
  • EFFECTIVENESS OF THE ELCATONIN TRANSDERMAL SYSTEM FOR THE TREATMENT OF OSTEOPOROSIS AND THE EFFECT OF THE COMBINATION OF ELCATONIN AND ACTIVE VITAMIN-D(3) IN RAT, T OGISO, M IWAKI, T TANINO, T PAKU, BIOLOGICAL & PHARMACEUTICAL BULLETIN, BIOLOGICAL & PHARMACEUTICAL BULLETIN, 16(9), 895 - 898, Sep. 1993
    Summary:The efficacy of percutaneous elcatonin (EC), a hypocalcemic peptide, in the treatment of experimental osteoporosis in rats was evaluated in vivo. Additionally, the effect of the combined use of EC and active vitamin D3 (1,25(OH)2D3) for the treatment was compared with those of three other groups: 1,25(OH)2D3 alone, estradiol plus 1,25(OH)2D3, and a placebo, and low calcium diet (low Ca). The EC transdermal system and the EC plus 1,25(OH)2D3 system, applied to the rat abdominal skin 6 times for 48 h, significantly increased the ash weight and calcium content of the tibia in the rats, compared with those of placebo group (p<0.05). The EC systems also slightly lowered the alkaline phosphatase activity in plasma of the morbid rats, without a difference in the plasma calcium content. These EC systems were superior to the 1,25(OH)2D3 system and the estradiol plus 1,25(OH)2D3 system in improving osteoporotic parameters. Thus, the EC systems were concluded to be an efficient drug delivery system for Paget's disease and osteoporosis.
  • PERCUTANEOUS-ABSORPTION OF TERODILINE AND THE MEMBRANE-CONTROLLED TRANSDERMAL THERAPEUTIC SYSTEM, T OGISO, M IWAKI, T TANINO, M YATOMI, C TSUJIMOTO, INTERNATIONAL JOURNAL OF PHARMACEUTICS, INTERNATIONAL JOURNAL OF PHARMACEUTICS, 98(1-3), 113 - 120, Aug. 1993
    Summary:In an attempt to prepare a transdermal dosage form of terodiline which is extensively metabolized in man, the absorption of terodiline, an anticholinergic and calcium antagonist, through rat skin was estimated in vitro and in vivo. Terodiline penetrated rapidly through the skin from the gel formulation without enhancers (penetration rate, 167.6 mug/h per cm2). Laurocapram, a potent enhancer, did not enhance the absorption in vitro. When the gel formulation (0.9 g) was applied to rat abdominal skin (6 cm2), high plasma concentrations (C(max), 8.8 +/- 3.4 mug/ml) of terodiline were observed for 24 h, thereby resulting in a high bioavailability equivalent to that after intravenous injection. The application of a transdermal therapeutic system, prepared using the gel formulation and a microporous membrane, gave a constant plasma level of terodiline, 250-820 ng/ml, for about 48 h, indicating that the membrane-controlled systems may be an efficient drug delivery system for treatment of urinary urge incontinence.
  • PERCUTANEOUS-ABSORPTION OF ACEMETACIN FROM A MEMBRANE CONTROLLED TRANSDERMAL SYSTEM AND PREDICTION OF THE DISPOSITION OF THE DRUG IN RATS, Y ITO, T OGISO, M IWAKI, T TANINO, M TERAO, BIOLOGICAL & PHARMACEUTICAL BULLETIN, BIOLOGICAL & PHARMACEUTICAL BULLETIN, 16(6), 583 - 588, Jun. 1993
    Summary:To avoid development of a lesion on the small intestine by acemetacin (ACM) following oral administration of the drug, we developed a new device for its percutaneous application. The device for transdermal application of ACM consisted of a silicon 0-ring, a backing of aluminum foil and adhesive tape, and rate-controlling membranes with three different pore sizes (HP-1100, 2100 and 4050). Two percent ACM gel ointment was contained in the device. In the in vitro release experiment, the ACM release from the device was limited by these membranes with release rate constants of 0.630+/-0.052, 0.289+/-0.012, 0.098+/-0.11 and 0.083+/-0.011 h-1 for no membrane, HP-4050, HP-2100 and HP-1100 membranes, respectively. In the in vitro penetration experiment, the ACM penetrating through the skin appeared in the reservoir cell without the metabolic conversion to indomethacin (IM). After the application of the ACM device with the HP-2100 rate-controlling membrane on the rat abdominal skin, ACM was not detected in the plasma but the therapeutic plasma concentration of IM could be maintained over a 54h period. These results indicate that the device with a rate-controlling membrane may be useful for the percutaneous application of ACM as an anti-inflammatory drug and its clinical application. For the percutaneous absorption of ACM after application of the ACM devices, the values estimated by the proposed model which consisted of 6 compartments well fit to the data obtained from this in vivo experiment. It has therefore been proved that the model described in this paper can significantly predict plasma IM profiles after application of the ACM device.
  • RECTAL ABSORPTION OF ACYCLOVIR IN RATS AND IMPROVEMENT OF ABSORPTION BY TRIGLYCERIDE BASE, T OGISO, M IWAKI, T TANINO, J FUJII, T PAKU, BIOLOGICAL & PHARMACEUTICAL BULLETIN, BIOLOGICAL & PHARMACEUTICAL BULLETIN, 16(3), 315 - 318, Mar. 1993
    Summary:The rectal absorption of acyclovir has been evaluated after administration of suppositories without absorption enhancers in rats. The disappearance of plasma acyclovir followed biexponential kinetics after i.v. dosing. Rectal administration of a triglyceride (Vosco S-55 and Vosco S-55+methylcellulose) suppository gave relatively high plasma concentrations and bioavailabilities (95.3 and 83.4%, respectively) compared with Witepsol and macrogol suppositories. However, the in vitro release profiles from suppositories did not accurately reflect plasma concentrations after rectal dosing. Our results suggest that the rectal administration of acyclovir suppositories may be a promising substitute for intravenous infusion, which is at present used for the treatment.
  • EFFECT OF MEXILETINE ON ELIMINATION AND METABOLIC CONVERSION OF THEOPHYLLINE AND ITS MAJOR METABOLITES IN RATS, T OGISO, M IWAKI, T TANINO, K OKUYAMA, S UNO, BIOLOGICAL & PHARMACEUTICAL BULLETIN, BIOLOGICAL & PHARMACEUTICAL BULLETIN, 16(2), 163 - 167, Feb. 1993
    Summary:In an attempt to clarify the possible mechanism of the interaction between theophylline (TP) and mexiletine (ME), the elimination kinetics and in vitro metabolism of TP and its metabolites were investigated in rats. The plasma elimination of TP, 1,3-dimethyluric acid (1,3-DMU) and 1-methyluric acid (1-MU) was significantly delayed by the intravenous (i.v.) administration of ME. The oral administration of ME also decreased the elimination rate of TP to the same extent as the i.v. dosing. The in vitro metabolic experiment showed that ME significantly inhibited the metabolic conversion of TP to 1,3-DMU and, 1,3-DMU to 1-MU, and slightly inhibited the conversion of TP to 3-methylxanthine, these processes being mediated by microsomal enzymes, with no inhibition of xanthine oxidase. Our results indicated that ME could inhibit the metabolic conversion of TP and its metabolite in rat, as reported in man.
  • PERCUTANEOUS-ABSORPTION OF BROMHEXINE IN RATS, T OGISO, M IWAKI, S TSUJI, CHEMICAL & PHARMACEUTICAL BULLETIN, CHEMICAL & PHARMACEUTICAL BULLETIN, 39(6), 1609 - 1611, Jun. 1991
    Summary:The percutaneous absorption of bromhexine (BH), an expectorant drug, through rat skin was examined in vitro and in vivo. BH in free base form penetrated better than the hydrochloride through the skin. When the in vitro penetration of BH was compared using Plastibase, macrogol and sucrose ester of fatty acid F-160 (DK-ester) formulations, the DK-ester formulation showed the best penetration of BH of the three. The addition of Azone (3%) or lauric acid (BH: lauric acid molar ratio, 1:1) considerably increased BH penetration to a relatively large penetration rate. The plasma levels of BH after in vivo application of the DK-ester formulation with Azone or lauric acid (0.6 g/3.8 cm2) were also higher than those after the formulation without an enhancer, and a constant plasma level (20-50 ng/ml) was obtained during the application for 48h. However, the bioavailability was low, 2.5 and 2.7% respectively. When the amount of BH remaining in DK-ester ointment and the skin after an 18-h application was measured, the BH content in the ointment was 88.6 +/- 8.0% for the formulation without Azone and 93.7 +/- 6.9% for that with Azone. The low penetration and low bioavailability observed will thus be due to the high drug retention of the base.
  • Drug Interaction between Cyproheptadine and Tipepidine. Effect of Single and Repeated Administration, Journal of Pharmacobio-Dynamics, Journal of Pharmacobio-Dynamics, 14, 1991
  • INHIBITORY EFFECT OF VALPROIC ACID ON METABOLIC-CLEARANCE OF CARBAMAZEPINE EPOXIDE, T OGISO, Y ITO, M IWAKI, Y HORIBE, JOURNAL OF PHARMACOBIO-DYNAMICS, JOURNAL OF PHARMACOBIO-DYNAMICS, 13(4), 238 - 245, Apr. 1990
  • DRUG-INTERACTION BETWEEN PHENYTOIN AND ALLOPURINOL, T OGISO, Y ITO, M IWAKI, K TSUNEKAWA, JOURNAL OF PHARMACOBIO-DYNAMICS, JOURNAL OF PHARMACOBIO-DYNAMICS, 13(1), 36 - 43, Jan. 1990
  • Pharmacokinetics and First-Pass Effect of Bromhexine in Rats, Journal of Pharmacobio-Dynamics, Journal of Pharmacobio-Dynamics, 13, 1990
  • PHARMACOKINETICS AND BIOTRANSFORMATION OF HYDRALAZINE ACETONE HYDRAZONE, A METABOLITE OF HYDRALAZINE, IN THE RAT, M IWAKI, T OGISO, Y ITO, JOURNAL OF PHARMACEUTICAL SCIENCES, JOURNAL OF PHARMACEUTICAL SCIENCES, 78(10), 867 - 873, Oct. 1989
  • A PHARMACOKINETIC MODEL FOR THE PERCUTANEOUS-ABSORPTION OF INDOMETHACIN AND THE PREDICTION OF DRUG DISPOSITION KINETICS, T OGISO, Y ITO, M IWAKI, H ATAGO, JOURNAL OF PHARMACEUTICAL SCIENCES, JOURNAL OF PHARMACEUTICAL SCIENCES, 78(4), 319 - 323, Apr. 1989
  • INVITRO KINETIC-STUDIES OF THE REACTION OF HYDRALAZINE AND ITS ACETONE HYDRAZONE WITH PYRUVIC-ACID, M IWAKI, T OGISO, Y ITO, JOURNAL OF PHARMACEUTICAL SCIENCES, JOURNAL OF PHARMACEUTICAL SCIENCES, 77(3), 280 - 283, Mar. 1988
  • Effect of Furosemide and Trimethazidine on Kinetic Behavior and Hypotensive Effect of Hydralazine in Rats, Journal of Pharmacobio-Dynamics, Journal of Pharmacobio-Dynamics, 9, 1986
  • Pharmacokinetics of Formation and Excretion of Some Metabolites of Hydralazine and Their Hypotensive Effect in Rats, Journal of Pharmacology and Experimental Therapy, Journal of Pharmacology and Experimental Therapy, 233(2), 1985
  • BINDING OF HYDRALAZINE AND A MAJOR METABOLITE, PYRUVATE HYDRAZONE, TO RAT PLASMA-PROTEIN AND HUMAN-SERUM ALBUMIN, T OGISO, M IWAKI, CHEMICAL & PHARMACEUTICAL BULLETIN, CHEMICAL & PHARMACEUTICAL BULLETIN, 32(8), 3155 - 3163, 1984
  • Hydralazine-Phenobarbital Interactions in Rats. II. Disposition of Hydralazine and Its Acid-labile Conjugates, and Liver Drug-metabolizing Enzyme Activities in Normotensive and spontaneoisly Hypertensive Rats, TARO OGISO, MASAHIRO IWAKI, NOBUMICHI OHTSUKI, Chemical Pharmaceutical Bulletin, Chemical Pharmaceutical Bulletin, 31(1), 247 - 255, 1983
  • PHARMACODYNAMIC INTERACTION BETWEEN HYDRALAZINE AND PHENOBARBITAL IN NORMOTENSIVE AND SPONTANEOUSLY HYPERTENSIVE RATS, T OGISO, M IWAKI, H MATSUOKA, CHEMICAL & PHARMACEUTICAL BULLETIN, CHEMICAL & PHARMACEUTICAL BULLETIN, 30(10), 3711 - 3718, 1982

Conference Activities & Talks

  • Effects of Mrp2- and Mrp3-knockdown in mice on covalent adduct formation of acyl glucuronide using shRNA-expressing adenovirus vector, Pharmaceutical Sciences World Congress 2010,   2010 , Pharmaceutical Sciences World Congress 2010
  • The effect of fasting and hyperlipidemia on the disposition of pravastatin in the in situ perfused rat liver model, Pharmaceutical Sciences World Congress 2010,   2010 , Pharmaceutical Sciences World Congress 2010
  • Differences in Cytochrome P450 and Nuclear Receptor mRNA Levels in Liver and Small Intestines between SD and DA Rats, 69th International Congress of FIP,   2009 , 69th International Congress of FIP
  • Changes in mRNA Expression of ABC and SLC Transporters in Liver and Intestines of the Adjuvant-induced Arthritis Rat, 69th International Congress of FIP,   2009 , 69th International Congress of FIP
  • Differences in cytochrome P450 and nuclear receptor mRNA levels in liver and small intestine between SD and DA rats, 2nd Asian Pacific Regional ISSX Meeting,   2008 , 2nd Asian Pacific Regional ISSX Meeting
  • Alteration on the mRNA expression of ABC and SLC transporters in liver and intestine of adjuvant-induced arthritis rat, 2nd Asian Pacific Regional ISSX Meeting,   2008 , 2nd Asian Pacific Regional ISSX Meeting
  • Effects of CAR on bilirubin metabolism in mouse collagen-induced arthritis, Pharmaceutical Sciences World Congress 2007,   2007 , Pharmaceutical Sciences World Congress 2007
  • Inflammation impairs intrinsic chiral inversion activity of "Profen", nonsteroidal antiinflammatory drug, Pharmaceutical Sciences World Congress 2007,   2007 , Pharmaceutical Sciences World Congress 2007
  • Decreased Intestinal Detoxification Functions in an Absorption Process in Adjuvant-Induced Arthritis Rats,   2005
  • Alteration in Factors Affecting Drug Disposition during Development of Adjuvant-Induced Arthritis in Rats,   2005
  • Usefulness of hepatocytes for evaluating the genetic polymorphism of CYP2D6 substrates,   2005

Patents

  • Evodia extracts as dermal absorption accelerators, JP 2003226651 A2 20030812

Awards & Honors

  •   2018 11 , Pharmacy Society of Japan, Distinguished Service Award by Pharmacy Society of Japan

Research Grants & Projects

  • Drug Metabolism and Disposition in Disease
  • Studies on Pharmacokinetics
  • Toxicokinetics
  • Study on mechanism of adverse side-effect
  • Study on Drug Interactions