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Drug Metabolism and Pharmacokinetics

Riya Shrestha, Ju-Hyun Kim, Wongshik Nam, Hye Suk Lee, Jae-Mok Lee, Sangkyu Lee
Fisetin is a flavonol compound commonly found in edible vegetables and fruits. It has anti-tumor, antioxidant, and anti-inflammatory effects. Geraldol, the O-methyl metabolite of fisetin in mice, is reported to suppress endothelial cell migration and proliferation. Although the in vivo and in vitro effects of fisetin and its metabolites are frequently reported, studies on herb-drug interactions have not yet been performed. This study was designed to investigate the inhibitory effect of fisetin and geraldol on eight isoforms of human cytochrome P450 (CYP) by using cocktail assay and LC-MS/MS analysis...
January 31, 2018: Drug Metabolism and Pharmacokinetics
Lei Li, Qing-Yu Zhang, Xinxin Ding
CYP2B6 is a human microsomal cytochrome P450 enzyme with broad substrate selectivity. CYP2B6 is the only functional member of the human CYP2B gene subfamily, which differs from the situation in rodents, such as mouse, where multiple functional Cyp2b genes are expressed. Recent studies with Cyp2b knockout or knockdown mouse models have yielded insights into the in vivo roles of mouse CYP2B enzymes in drug disposition and xenobiotic toxicity. A CYP2B6-humanized mouse model (CYP2A13/2B6/2F1-transgenic/Cyp2abfgs-null), which expresses human CYP2B6 in the liver, and human CYP2A13 and CYP2F1 in the respiratory tract, but not any of the mouse Cyp2b genes, has also been established...
January 11, 2018: Drug Metabolism and Pharmacokinetics
Seiichi Ishida
Assay systems using in vitro cultured cells are increasingly applied for evaluation of the efficacy, safety, and toxicity of drug candidates. In vitro cell-based assays have two main applications in the drug discovery process: searching for a compound that is effective against the target disease (seed investigation) and confirmation of safety during use of the identified compounds (safety assessment). Currently available in vitro cell-based assays have been designed to evaluate the efficacy and toxicity in single organs, but the in vivo pharmacokinetics and pharmacodynamics of the administered drug candidates have not been considered...
January 11, 2018: Drug Metabolism and Pharmacokinetics
Daisuke Satoh, Satoshi Abe, Kaoru Kobayashi, Yoshihiro Nakajima, Mitsuo Oshimura, Yasuhiro Kazuki
In the earliest stage of drug discovery/development, various cell-based models and animal models were used for the prediction of human pharmacokinetics and toxicokinetics. Unfortunately, drugs under development are often discontinued because their nonclinical results do not extrapolate to human clinical studies in relation to either safety or efficacy. Therefore, it is important to improve the time- and cost-effectiveness of drug development. This might be achieved by developing new technologies including pharmacokinetics and toxicokinetics models that use human and mouse artificial chromosome vectors (HACs/MACs)...
January 11, 2018: Drug Metabolism and Pharmacokinetics
(no author information available yet)
No abstract text is available yet for this article.
February 2018: Drug Metabolism and Pharmacokinetics
Verawan Uchaipichat
This study aimed to investigate the liver microsomal inhibitory effects of silybin, silychristin, andrographolide, and curcumin by using morphine as an in vitro UGT2B7 probe substrate, and predict the magnitude of the herb-drug interaction arising from these herbal constituents' inhibition in vivo. Studies were performed in the incubation with and without bovine serum albumin (BSA). Andrographolide and curcumin showed a marked inhibition on morphine 3- and 6-glucuronidation with IC50 of 50&87 and 96&111 μM, respectively...
February 2018: Drug Metabolism and Pharmacokinetics
Guangzhao Qi, Duolu Li, Xiaojian Zhang
Interindividual and interethnic variability of drug responses could be attributed to the differences of genetic polymorphisms in the drug metabolizing enzymes and transporters genes among the populations. Here we reviewed the studies of genetic variations in Uyghur Chinese of fifteen CYP450 genes including CYP1A1, CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2E1, CYP2J2, CYP2W1, CYP3A4, CYP3A5, CYP4A11, and CYP17A1, which totally covered 277 variants. We also collected the data of 277 variants covered in our study in two extensive population sequencing projects, the International HapMap Project (Hap-Map) and the 1000 Genomes Project and compared them with the data of Uyghur Chinese...
February 2018: Drug Metabolism and Pharmacokinetics
Dabin Jeong, Hyoung-Goo Park, Young-Ran Lim, Yejin Lee, Vitchan Kim, Myung-A Cho, Donghak Kim
The human cytochrome P450 2J2 is involved in several metabolic reactions, including the oxidation of important therapeutics and epoxidation of endogenous arachidonic acid. At least ten genetic variations of P450 2J2 have been identified, but their effects on enzymatic activity have not been clearly characterized. Here, we evaluated the functional effects of three genetic variations of P450 2J2 (G312R, P351L, and P115L). Recombinant enzymes of wild-type and three variant P450 2J2 were heterologously expressed in Escherichia coli and purified...
February 2018: Drug Metabolism and Pharmacokinetics
Toshiyuki Kanamori, Shinji Sugiura, Yasuyuki Sakai
Microphysiological systems (MPS) are currently attracting a lot of interest from pharmaceutical companies worldwide. In the United States and European Union, several large government projects related to MPS have been initiated, and, in Japan, pharmaceutical companies interested in MPS are watching the recent trends and developments in the field. In July 2017, the Japan Agency for Medical Research and Development initiated a research program to develop chip-based MPS. In this review, we examine the technical aspects of commercializing chip-based MPS...
February 2018: Drug Metabolism and Pharmacokinetics
Yoichi Naritomi, Seigo Sanoh, Shigeru Ohta
Predicting human drug metabolism and pharmacokinetics (PK) is key to drug discovery. In particular, it is important to predict human PK, metabolite profiles and drug-drug interactions (DDIs). Various methods have been used for such predictions, including in vitro metabolic studies using human biological samples, such as hepatic microsomes and hepatocytes, and in vivo studies using experimental animals. However, prediction studies using these methods are often inconclusive due to discrepancies between in vitro and in vivo results, and interspecies differences in drug metabolism...
February 2018: Drug Metabolism and Pharmacokinetics
Hiroshi Kimura, Yasuyuki Sakai, Teruo Fujii
Although animal experiments are indispensable for preclinical screening in the drug discovery process, various issues such as ethical considerations and species differences remain. To solve these issues, cell-based assays using human-derived cells have been actively pursued. However, it remains difficult to accurately predict drug efficacy, toxicity, and organs interactions, because cultivated cells often do not retain their original organ functions and morphologies in conventional in vitro cell culture systems...
February 2018: Drug Metabolism and Pharmacokinetics
Kenji Tabata, Hideki Hirabayashi
No abstract text is available yet for this article.
December 21, 2017: Drug Metabolism and Pharmacokinetics
Tomohisa Nakada, Toshiyuki Kudo, Toshiyuki Kume, Hiroyuki Kusuhara, Kiyomi Ito
Serum creatinine (SCr) levels rise during trimethoprim therapy for infectious diseases. This study aimed to investigate whether the elevation of SCr can be quantitatively explained using a physiologically-based pharmacokinetic (PBPK) model incorporating inhibition by trimethoprim on tubular secretion of creatinine via renal transporters such as organic cation transporter 2 (OCT2), OCT3, multidrug and toxin extrusion protein 1 (MATE1), and MATE2-K. Firstly, pharmacokinetic parameters in the PBPK model of trimethoprim were determined to reproduce the blood concentration profile after a single intravenous and oral administration of trimethoprim in healthy subjects...
December 5, 2017: Drug Metabolism and Pharmacokinetics
Ryutaro Matsui, Ryutaro Hattori, Youhei Usami, Masumi Koyama, Yuki Hirayama, Emi Matsuba, Yukiya Hashimoto
We have recently found an H+/quinidine (a lipophilic cation, QND) antiport system in Madin-Darby canine kidney (MDCK) cells. The primary aim of the present study was to evaluate whether the H+/lipophilic cation antiport system is expressed in porcine LLC-PK1 cells. That is, we investigated uptake and/or efflux of QND and another cation, bisoprolol, in LLC-PK1 cells. In addition, we studied the renal clearance of bisoprolol in rats. Uptake of QND into LLC-PK1 cells was decreased by acidification of the extracellular pH or alkalization of the intracellular pH...
December 5, 2017: Drug Metabolism and Pharmacokinetics
Kumiko Ueda, Ayasa Masuda, Misaki Fukuda, Shota Tanaka, Mika Hosokawa, Seigo Iwakawa
Decitabine (DAC), a nucleoside-related DNA methylation inhibitor, is taken up into cancer cells via equilibrative nucleoside transporter 1 (ENT1), and is then monophosphorylated by deoxycytidine kinase (dCK). In the present study, we examined the contribution of dCK to the uptake of DAC in HCT116 colon cancer cells. Irinotecan and etoposide inhibited the uptake of [3 H]-uridine and [3 H]-DAC at 10 s and 5 min, while cytarabine and gemcitabine only inhibited that of [3 H]-DAC at 5 min. Irinotecan and etoposide inhibited [3 H]-DAC uptake in negative control small interfering RNA (siRNA)- or dCK siRNA-transfected cells at 10 s, whereas cytarabine and gemcitabine did not...
December 2017: Drug Metabolism and Pharmacokinetics
Kenta Haraya, Motohiro Kato, Koji Chiba, Yuichi Sugiyama
Inter-individual variability in pharmacokinetics can lead to unexpected side effects and treatment failure, and is therefore an important factor in drug development. CYP2C8 is a major drug-metabolizing enzyme known to be involved in the metabolism of over 100 drugs. In this study, we predicted the inter-individual variability in AUC/Dose of CYP2C8 substrates in healthy volunteers using the Monte Carlo simulation. Inter-individual variability in the hepatic intrinsic clearance of CYP2C8 substrates (CLint,h,2C8 ) was estimated from the inter-individual variability in pharmacokinetics of pioglitazone, which is a major CYP2C8 substrate...
December 2017: Drug Metabolism and Pharmacokinetics
Takahiro Yamashiro, Tomoya Yasujima, Kinya Ohta, Katsuhisa Inoue, Hiroaki Yuasa
Myricetin is a flavonoid that inhibits human proton-coupled folate transporter (hPCFT) in a transient manner, in which inhibition is manifested in its presence, and also in a sustained manner, in which inhibition induced in its presence persists after its removal. In an effort to elucidate the mechanisms involved in those, we examined if myricetin might or might not act similarly on some other transporters. Transporters examined for that, in comparison with hPCFT, were its rat ortholog (rPCFT) and human riboflavin transporter 3 (hRFVT3)...
December 2017: Drug Metabolism and Pharmacokinetics
Yuki Asai, Yukiko Sakakibara, Masayuki Nadai, Miki Katoh
Because UDP-glucuronosyltransferase (Ugt) 1a6 and Ugt1a7 are highly expressed in the rat brain, changes in Ugt1a6 and Ugt1a7 expression may affect the pharmacokinetics of drugs and endogenous compounds in the brain. The present study aimed to elucidate the effect of carbamazepine (CBZ), a typical UGT inducer, on Ugt1a6 and Ugt1a7 expression in the rat brain. Sprague-Dawley rats were treated intraperitoneally for 7 d with CBZ (100 mg/kg/d). Ugt1a6 and Ugt1a7 mRNAs were induced by CBZ in the cerebellum, piriform cortex, and hippocampus (Ugt1a6: 3...
December 2017: Drug Metabolism and Pharmacokinetics
Hiroyuki Kusuhara, Tadayuki Takashima, Hisako Fujii, Tsutomu Takashima, Masaaki Tanaka, Akira Ishii, Shusaku Tazawa, Kazuhiro Takahashi, Kayo Takahashi, Hidekichi Tokai, Tsuneo Yano, Makoto Kataoka, Akihiro Inano, Suguru Yoshida, Takamitsu Hosoya, Yuichi Sugiyama, Shinji Yamashita, Taisuke Hojo, Yasuyoshi Watanabe
The aim of the present study is to investigate the pharmacokinetics of our newly developed aromatase inhibitors (cetrozole and TMD-322) in healthy subjects by a cassette microdose strategy. A cocktail of cetrozole and TMD-322 was administered intravenously or orally (1.98 μg for each drug) to six healthy volunteers in a crossover fashion. Anastrozole (1.98 μg) was also included in the oral cocktail. Total body clearance and bioavailability were 12.1 ± 7.1 mL/min/kg and 34.9 ± 32.3% for cetrozole, and 16...
December 2017: Drug Metabolism and Pharmacokinetics
Makiko Nakamura, Kyoko Fujita, Yu Toyoda, Tappei Takada, Hiroshi Hasegawa, Kimiyoshi Ichida
Hyperuricemia induces gout and kidney stones and accelerates the progression of renal and cardiovascular diseases. Adenosine 5'-triphosphate-binding cassette subfamily G member 2 (ABCG2) is a urate transporter, and common dysfunctional variants of ABCG2, non-functional Q126X (rs72552713) and semi-functional Q141K (rs2231142), are risk factors for hyperuricemia and gout. A recent genome wide association study suggested that allopurinol, a serum uric acid-lowering drug that inhibits xanthine dehydrogenase, is a potent substrate of ABCG2...
November 22, 2017: Drug Metabolism and Pharmacokinetics
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