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Kojima Y, Fujieda S, Zhou L, Takikawa M, Kuramochi K, Furuya T, Mizumoto A, Kagaya N, Kawahara T, Shin-Ya K, Dan S, Tomida A, Ishikawa F, Sadaie M. Cytochrome P450 2J2 is required for the natural compound austocystin D to elicit cancer cell toxicity. Cancer Sci 2024. [PMID: 39009033 DOI: 10.1111/cas.16289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Revised: 06/25/2024] [Accepted: 07/04/2024] [Indexed: 07/17/2024] Open
Abstract
Austocystin D is a natural compound that induces cytochrome P450 (CYP) monooxygenase-dependent DNA damage and growth inhibition in certain cancer cell lines. Cancer cells exhibiting higher sensitivity to austocystin D often display elevated CYP2J2 expression. However, the essentiality and the role of CYP2J2 for the cytotoxicity of this compound remain unclear. In this study, we demonstrate that CYP2J2 depletion alleviates austocystin D sensitivity and DNA damage induction, while CYP2J2 overexpression enhances them. Moreover, the investigation into genes involved in austocystin D cytotoxicity identified POR and PGRMC1, positive regulators for CYP activity, and KAT7, a histone acetyltransferase. Through genetic manipulation and analysis of multiomics data, we elucidated a role for KAT7 in CYP2J2 transcriptional regulation. These findings strongly suggest that CYP2J2 is crucial for austocystin D metabolism and its subsequent cytotoxic effects. The potential use of austocystin D as a therapeutic prodrug is underscored, particularly in cancers where elevated CYP2J2 expression serves as a biomarker.
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Affiliation(s)
- Yukiko Kojima
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda, Chiba, Japan
| | - Saki Fujieda
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda, Chiba, Japan
| | - Liya Zhou
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda, Chiba, Japan
| | - Masahiro Takikawa
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda, Chiba, Japan
| | - Kouji Kuramochi
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda, Chiba, Japan
| | - Toshiki Furuya
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda, Chiba, Japan
| | - Ayaka Mizumoto
- Department of Gene Mechanisms, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Noritaka Kagaya
- National Institute of Advanced Industrial Science and Technology (AIST), Tokyo, Japan
| | - Teppei Kawahara
- Japan Biological Informatics Consortium (JBIC), Tokyo, Japan
| | - Kazuo Shin-Ya
- National Institute of Advanced Industrial Science and Technology (AIST), Tokyo, Japan
| | - Shingo Dan
- Cancer Chemotherapy Center, Japanese Foundation for Cancer Research (JFCR), Tokyo, Japan
| | - Akihiro Tomida
- Cancer Chemotherapy Center, Japanese Foundation for Cancer Research (JFCR), Tokyo, Japan
| | - Fuyuki Ishikawa
- Department of Gene Mechanisms, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Mahito Sadaie
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda, Chiba, Japan
- Department of Gene Mechanisms, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
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Dai Z, Wu Y, Xiong Y, Wu J, Wang M, Sun X, Ding X, Yang L, Sun X, Ge G. CYP1A inhibitors: Recent progress, current challenges, and future perspectives. Med Res Rev 2024; 44:169-234. [PMID: 37337403 DOI: 10.1002/med.21982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 03/28/2023] [Accepted: 05/23/2023] [Indexed: 06/21/2023]
Abstract
Mammalian cytochrome P450 1A (CYP1A) are key phase I xenobiotic-metabolizing enzymes that play a distinctive role in metabolic activation or metabolic clearance of a variety of procarcinogens, drugs, and endogenous substances. Human CYP1A subfamily contains two members (hCYP1A1 and hCYP1A2), which are known to catalyze the oxidative activation of some environmental procarcinogens into carcinogenic species. Increasing evidence has demonstrated that CYP1A inhibitor therapies are promising strategies for cancer chemoprevention or overcoming CYP1A-associated drug toxicity and resistance. Herein, we reviewed recent advances in the discovery and characterization of hCYP1A inhibitors, from the discovery approaches to structural features and biomedical applications of hCYP1A inhibitors. The inhibition potentials, inhibition modes, and inhibition constants of all reported hCYP1A inhibitors are comprehensively summarized. Meanwhile, the structural features and structure-activity relationships of different classes of hCYP1A1 and hCYP1A2 inhibitors are analyzed and discussed in depth. Furthermore, the major challenges and future directions for this field are presented and highlighted. Collectively, the information and knowledge presented here will strongly facilitate the researchers to discover and develop more efficacious CYP1A inhibitors for specific purposes, such as chemo-preventive agents or as tool molecules in hCYP1A-related fundamental studies.
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Affiliation(s)
- Ziru Dai
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Yue Wu
- Shanghai Frontiers Science Center for TCM Chemical Biology, Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Yuan Xiong
- Shanghai Frontiers Science Center for TCM Chemical Biology, Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Jingjing Wu
- Department of Clinical Pharmacology, College of Pharmacy, Dalian Medical University, Dalian, China
| | - Min Wang
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Xiao Sun
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Xinxin Ding
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, Tucson, America
| | - Ling Yang
- Key Laboratory of Basic Pharmacology of Ministry of Education and Joint International Research Laboratory of Ethnomedicine of Ministry of Education, Zunyi Medical University, Zunyi, China
| | - Xiaobo Sun
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Guangbo Ge
- Shanghai Frontiers Science Center for TCM Chemical Biology, Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, Shanghai, China
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Lootens O, De Boevre M, Gasthuys E, Van Bocxlaer J, Vermeulen A, De Saeger S. Unravelling the pharmacokinetics of aflatoxin B1: In vitro determination of Michaelis–Menten constants, intrinsic clearance and the metabolic contribution of CYP1A2 and CYP3A4 in pooled human liver microsomes. Front Microbiol 2022; 13:988083. [PMID: 36110298 PMCID: PMC9469084 DOI: 10.3389/fmicb.2022.988083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 08/04/2022] [Indexed: 11/13/2022] Open
Abstract
Mycotoxins, fungal secondary metabolites, are ubiquitously present in food commodities. Acute exposure to high levels or chronic exposure to low levels has an impact on the human body. The phase I metabolism in the human liver, performed by cytochrome P450 (CYP450) enzymes, is accountable for more than 80% of the overall metabolism of exogenous and endogenous compounds. Mycotoxins are (partially) metabolized by CYP450 enzymes. In this study, in vitro research was performed on CYP450 probes and aflatoxin B1 (AFB1), a carcinogenic mycotoxin, to obtain pharmacokinetic data on AFB1, required for further experimental work. The CYP450 probes of choice were a CYP3A4 substrate, midazolam (MDZ) and a CYP1A2 substrate, phenacetin (PH) since these are the main metabolizing phase I enzymes of AFB1. Linearity experiments were performed on the three substrates indicating that linear conditions were achieved at a microsomal protein concentration and incubation time of 0.25 mg/ml and 5 min, 0.50 mg/ml and 20 min and 0.25 mg/ml and 5 min for MDZ, PH and AFB1, respectively. The Km was determined in human liver microsomes and was estimated at 2.15 μM for MDZ, 40.0 μM for PH and 40.9 μM for AFB1. The associated Vmax values were 956 pmol/(mg.min) (MDZ), 856 pmol/(mg.min) (PH) and 11,536 pmol/(mg.min) (AFB1). Recombinant CYP systems were used to determine CYP450-specific Michaelis–Menten values for AFB1, leading to a CYP3A4 Km of 49.6 μM and an intersystem extrapolation factor (ISEF) corrected Vmax of 43.6 pmol/min/pmol P450 and a CYP1A2 Km of 58.2 μM and an ISEF corrected Vmax of 283 pmol/min/pmol P450. An activity adjustment factor (AAF) was calculated to account for differences between microsome batches and was used as a correction factor in the determination of the human in vivo hepatic clearance for MDZ, PH and AFB1. The hepatic blood clearance corrected for the AAF CLH,B,MDZ,AAF, CLH,B,PH,AAF CLH,B,AFB1,AAF(CYP3A4) and CLH,B,AFB1,AAF(CYP1A2) were determined in HLM at 44.1 L/h, 21.7 L/h, 40.0 L/h and 38.5 L/h. Finally, inhibition assays in HLM showed that 45% of the AFB1 metabolism was performed by CYP3A4/3A5 enzymes and 49% by CYP1A2 enzymes.
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Affiliation(s)
- Orphélie Lootens
- Department of Bioanalysis, Centre of Excellence in Mycotoxicology and Public Health, Ghent University, Ghent, Belgium
- Department of Bioanalysis, Laboratory of Medical Biochemistry and Clinical Analysis, Ghent University, Ghent, Belgium
- MYTOX-SOUTH, International Thematic Network, Ghent, Belgium
- *Correspondence: Orphélie Lootens,
| | - Marthe De Boevre
- Department of Bioanalysis, Centre of Excellence in Mycotoxicology and Public Health, Ghent University, Ghent, Belgium
- MYTOX-SOUTH, International Thematic Network, Ghent, Belgium
- Marthe De Boevre,
| | - Elke Gasthuys
- Department of Bioanalysis, Laboratory of Medical Biochemistry and Clinical Analysis, Ghent University, Ghent, Belgium
| | - Jan Van Bocxlaer
- Department of Bioanalysis, Laboratory of Medical Biochemistry and Clinical Analysis, Ghent University, Ghent, Belgium
| | - An Vermeulen
- Department of Bioanalysis, Laboratory of Medical Biochemistry and Clinical Analysis, Ghent University, Ghent, Belgium
| | - Sarah De Saeger
- Department of Bioanalysis, Centre of Excellence in Mycotoxicology and Public Health, Ghent University, Ghent, Belgium
- MYTOX-SOUTH, International Thematic Network, Ghent, Belgium
- Department of Biotechnology and Food Technology, University of Johannesburg, Johannesburg, Gauteng, South Africa
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Kumar AR, Patilea-Vrana GI, Anoshchenko O, Unadkat JD. Characterizing and Quantifying Extrahepatic Metabolism of (-)-Δ 9-Tetrahydrocannabinol (THC) and Its Psychoactive Metabolite, (±)-11-Hydroxy-Δ 9-THC (11-OH-THC). Drug Metab Dispos 2022; 50:734-740. [PMID: 35370140 PMCID: PMC9199115 DOI: 10.1124/dmd.122.000868] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 03/31/2022] [Indexed: 11/12/2023] Open
Abstract
(-)-Δ9-Tetrahydrocannabinol (THC) is the psychoactive constituent of cannabis, a drug recreationally consumed orally or by inhalation. Physiologically based pharmacokinetic (PBPK) modeling can be used to predict systemic and tissue exposure to THC and its psychoactive metabolite, (±)-11-hydroxy-Δ9-THC (11-OH-THC). To populate a THC/11-OH-THC PBPK model, we previously characterized the depletion clearance of THC (by CYP2C9) and 11-OH-THC (by UDP-glucuronosyltransferase (UGT), CYP3A, and CYP2C9) in adult human liver microsomes. Here we focused on quantifying extrahepatic depletion clearance of THC/11-OH-THC, important after oral (intestine) and inhalational (lung) consumption of THC as well as prenatal THC use (placenta and fetal liver). THC (500 nM) was metabolized in adult human intestinal microsomes (n = 3-5) by CYP2C9 [Vmax: 1.1 ± 0.38 nmol/min/mg; Michaelis-Menten constant (Km): 70 nM; intrinsic clearance (CLint): 15 ± 5.4 ml/min/mg; fraction metabolized (fm): 0.89 ± 0.31 at concentration ≪ 70 nM] and CYP3A (CLint: 2.0 ± 0.86 ml/min/mg; fm: 0.11 ± 0.050). 11-OH-THC (50 nM) was metabolized by CYP3A (CLint: 0.26 ± 0.058 ml/min/mg; fm: 0.51 ± 0.11) and UGT2B7 (CLint: 0.13 ± 0.027 ml/min/mg; fm: 0.25 ± 0.053). THC at 500 nM (CLint: 4.7 ± 0.22 ml/min/mg) and 11-OH-THC at 50 nM (CLint: 2.4 ± 0.13 ml/min/mg) were predominately (fm: 0.99 and 0.80, respectively) metabolized by CYP3A in human fetal liver microsomes (n = 3). However, we did not observe significant depletion of THC/11-OH-THC in adult lung, first trimester, second trimester, or term placentae microsomes. Using PBPK modeling and simulation, these data could be used in the future to predict systemic and tissue THC/11-OH-THC exposure in healthy and special populations. SIGNIFICANCE STATEMENT: This is the first characterization and quantification of (-)-Δ9-tetrahydrocannabinol (THC) and (±)-11-hydroxy-Δ9-THC (11-OH-THC) depletion clearance by cytochrome P450 and UDP-glucuronosyltransferase enzymes in extrahepatic human tissues: intestine, fetal liver, lung, and placenta. These data can be used to predict, through physiologically based pharmacokinetic modeling and simulation, systemic and tissue THC/11-OH-THC exposure after inhalational and oral THC use in both healthy and special populations (e.g., pregnant women).
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Affiliation(s)
- Aditya R Kumar
- Department of Pharmaceutics, University of Washington, Seattle, Washington
| | | | - Olena Anoshchenko
- Department of Pharmaceutics, University of Washington, Seattle, Washington
| | - Jashvant D Unadkat
- Department of Pharmaceutics, University of Washington, Seattle, Washington
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Identifying the Dominant Contribution of Human Cytochrome P450 2J2 to the Metabolism of Rivaroxaban, an Oral Anticoagulant. Cardiovasc Drugs Ther 2021; 36:121-129. [PMID: 33411110 DOI: 10.1007/s10557-020-07129-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/10/2020] [Indexed: 11/25/2022]
Abstract
PURPOSE Rivaroxaban, an oral anticoagulant, undergoes the metabolism mediated by human cytochrome P450 (CYP). The present study is to quantitatively analyze and compare the contributions of multiple CYPs in the metabolism of rivaroxaban to provide new information for medication safety. METHODS The metabolic stability of rivaroxaban in the presence of human liver microsomes (HLMs) and recombinant CYPs was systematically evaluated to estimate the participation of various CYP isoforms. Furthermore, the catalytic efficiency of CYP isoforms was compared via metabolic kinetic studies of rivaroxaban with recombinant CYP isoenzymes, as well as via CYP-specific inhibitory studies. Additionally, docking simulations were used to illustrate molecular interactions. RESULTS Multiple CYP isoforms were involved in the hydroxylation of rivaroxaban, with decreasing catalytic rates as follows: CYP2J2 > 3A4 > 2D6 > 4F3 > 1A1 > 3A5 > 3A7 > 2A6 > 2E1 > 2C9 > 2C19. Among the CYPs, 2J2, 3A4, 2D6, and 4F3 were the four major isoforms responsible for rivaroxaban metabolism. Notably, the intrinsic clearance of rivaroxaban catalyzed by CYP2J2 was nearly 39-, 64-, and 100-fold that catalyzed by CYP3A4, 2D6, and 4F3, respectively. In addition, rivaroxaban hydroxylation was inhibited by 41.1% in the presence of the CYP2J2-specific inhibitor danazol, which was comparable to the inhibition rate of 43.3% by the CYP3A-specific inhibitor ketoconazole in mixed HLMs. Furthermore, molecular simulations showed that rivaroxaban is principally bound to CYP2J2 by π-alkyl bonds, carbon-hydrogen bonds, and alkyl interactions. CONCLUSION CYP2J2 dominated the hydroxylation of rivaroxaban, which may provide new insight into clinical drug interactions involving rivaroxaban.
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Drug-Drug Interactions Involving Intestinal and Hepatic CYP1A Enzymes. Pharmaceutics 2020; 12:pharmaceutics12121201. [PMID: 33322313 PMCID: PMC7764576 DOI: 10.3390/pharmaceutics12121201] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 12/02/2020] [Accepted: 12/08/2020] [Indexed: 12/29/2022] Open
Abstract
Cytochrome P450 (CYP) 1A enzymes are considerably expressed in the human intestine and liver and involved in the biotransformation of about 10% of marketed drugs. Despite this doubtless clinical relevance, CYP1A1 and CYP1A2 are still somewhat underestimated in terms of unwanted side effects and drug–drug interactions of their respective substrates. In contrast to this, many frequently prescribed drugs that are subjected to extensive CYP1A-mediated metabolism show a narrow therapeutic index and serious adverse drug reactions. Consequently, those drugs are vulnerable to any kind of inhibition or induction in the expression and function of CYP1A. However, available in vitro data are not necessarily predictive for the occurrence of clinically relevant drug–drug interactions. Thus, this review aims to provide an up-to-date summary on the expression, regulation, function, and drug–drug interactions of CYP1A enzymes in humans.
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Juvonen RO, Ahinko M, Huuskonen J, Raunio H, Pentikäinen OT. Development of new Coumarin-based profluorescent substrates for human cytochrome P450 enzymes. Xenobiotica 2018; 49:1015-1024. [DOI: 10.1080/00498254.2018.1530399] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Risto O. Juvonen
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, Kuopio, Finland
| | - Mira Ahinko
- Department of Biological and Environmental Science and Nanoscience Center, University of Jyvaskyla, Jyvaskyla, Finland
| | - Juhani Huuskonen
- Department of Chemistry, University of Jyvaskyla, Jyvaskyla, Finland
| | - Hannu Raunio
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, Kuopio, Finland
| | - Olli T. Pentikäinen
- Department of Biological and Environmental Science and Nanoscience Center, University of Jyvaskyla, Jyvaskyla, Finland
- Institute of Biomedicine, Faculty of Medicine Integrative Physiology and Pharmacology, University of Turku, Turku, Finland
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Parmentier Y, Pothier C, Hewitt N, Vincent L, Caradec F, Liu J, Lin F, Trancart MM, Guillet F, Bouaita B, Chesne C, Walther B. Direct and quantitative evaluation of the major human CYP contribution (fmCYP) to drug clearance using the in vitro Silensomes™ model. Xenobiotica 2018; 49:22-35. [PMID: 29297729 DOI: 10.1080/00498254.2017.1422156] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
1. We have applied the concept of using MBIs to produce CYP-Silensomes to quantify the contribution of the major CYPs to drug metabolism (fmCYP). 2. The target CYPs were extensively and selectivity inhibited by the selected MBIs, while non-target CYPs were inhibited by less than 20% of the homologous control activities. Only CYP2D6-Silensomes exhibited a CYP2B6 inhibition that could be easily and efficiently encountered by subtracting the fmCYP2B6 measured using CYP2B6-Silensomes to adjust the fmCYP2D6. 3. To validate the use of a panel of 6 CYP-Silensomes, we showed that the fmCYP values of mono- and multi-CYP metabolised drugs were well predicted, with 70% within ± 15% accuracy. Moreover, the correlation with observed fmCYP values was higher than that for rhCYPs, which were run in parallel using the same drugs (<45% within ±15% accuracy). Moreover, the choice of the RAF substrate in rhCYP predictions was shown to affect the accuracy of the fmCYP measurement. 4. These results support the use of CYP1A2-, CYP2B6-, CYP2C8-, CYP2C9-, CYP2D6 and CYP3A4-Silensomes to accurately predict fmCYP values during the in vitro enzyme phenotyping assays in early, as well as in development, phases of drug development.
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Affiliation(s)
- Yannick Parmentier
- a Department of Biopharmaceutical Research , Technologie Servier , Orléans Cedex , France
| | - Corinne Pothier
- a Department of Biopharmaceutical Research , Technologie Servier , Orléans Cedex , France
| | | | - Ludwig Vincent
- a Department of Biopharmaceutical Research , Technologie Servier , Orléans Cedex , France
| | - Fabrice Caradec
- a Department of Biopharmaceutical Research , Technologie Servier , Orléans Cedex , France
| | - Jia Liu
- c SIMM-SERVIER Joint Biopharmacy Laboratory, Shanghai Institute of Materia Medica , Shanghai , China
| | - Feifei Lin
- c SIMM-SERVIER Joint Biopharmacy Laboratory, Shanghai Institute of Materia Medica , Shanghai , China
| | | | | | | | | | - Bernard Walther
- a Department of Biopharmaceutical Research , Technologie Servier , Orléans Cedex , France
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Li K, Guo X, Qin F, Xiong Z, Zhao L, Yu J. Identification of the cytochrome P450 enzymes involved in the oxidative metabolism of trantinterol using ultra high-performance liquid chromatography coupled with tandem mass spectrometry. RSC Adv 2018; 8:34764-34772. [PMID: 35548639 PMCID: PMC9086916 DOI: 10.1039/c8ra06219f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 10/04/2018] [Indexed: 11/24/2022] Open
Abstract
Trantinterol is a novel β2-adrenoceptor agonist used for the treatment of asthma. This study aimed to identify the cytochrome P450 enzymes responsible for the metabolism of trantinterol to form 4-hydroxylamine trantinterol (M1) and tert-butyl hydroxylated trantinterol (M2), which was achieved using the chemical inhibition study, followed by the metabolism study of trantinterol in a panel of recombinant CYPs, as well as the kinetic study with the appropriate cDNA-expressed P450 enzymes. A highly selective and sensitive ultra high-performance liquid chromatography tandem mass spectrometry method was developed and validated for the simultaneous determination of M1 and M2. The inhibition study suggested that CYP2C19 and CYP3A4/5 were involved in the formation of M1 and M2, and CYP2D6 only contributed to the formation of M1. Assays with cDNA-expressed CYP enzymes further showed that the relative contributions of P450 isoforms were 2C19 > 3A4 > 2D6 > 2E1 for the formation of M1, and 3A4 > 2C19 > 2D6 for the formation of M2. The enzyme kinetic analysis was then performed in CYP2C19, CYP2D6 and CYP3A4. The kinetic parameters were determined and normalized with respect to the human hepatic microsomal P450 isoform concentrations. All the results support the conclusion that CYP3A4 and CYP2C19 are the major enzymes responsible for formation of M1 and M2, while CYP2D6 and CYP2E1 also engaged to a lesser degree. The results imply that potential drug–drug interactions may be noticed when trantinterol is used with CYP2C19 and CYP3A4 inducers or inhibitors, and we should pay attention to this phenomenon in clinical study. The first report on the characterization of the main CYP450 enzymes and the kinetic study involved in trantinterol metabolism.![]()
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Affiliation(s)
- Kunjie Li
- Department of Analytical Chemistry
- School of Pharmacy
- Shenyang Pharmaceutical University
- Shenyang 110016
- China
| | - Xingjie Guo
- Department of Analytical Chemistry
- School of Pharmacy
- Shenyang Pharmaceutical University
- Shenyang 110016
- China
| | - Feng Qin
- Department of Analytical Chemistry
- School of Pharmacy
- Shenyang Pharmaceutical University
- Shenyang 110016
- China
| | - Zhili Xiong
- Department of Analytical Chemistry
- School of Pharmacy
- Shenyang Pharmaceutical University
- Shenyang 110016
- China
| | - Longshan Zhao
- Department of Analytical Chemistry
- School of Pharmacy
- Shenyang Pharmaceutical University
- Shenyang 110016
- China
| | - Jia Yu
- Department of Analytical Chemistry
- School of Pharmacy
- Shenyang Pharmaceutical University
- Shenyang 110016
- China
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Effect of ketoconazole on the transport and metabolism of drugs in the human liver cell model. Russ Chem Bull 2017. [DOI: 10.1007/s11172-017-1713-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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Backman JT, Filppula AM, Niemi M, Neuvonen PJ. Role of Cytochrome P450 2C8 in Drug Metabolism and Interactions. Pharmacol Rev 2016; 68:168-241. [PMID: 26721703 DOI: 10.1124/pr.115.011411] [Citation(s) in RCA: 142] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
During the last 10-15 years, cytochrome P450 (CYP) 2C8 has emerged as an important drug-metabolizing enzyme. CYP2C8 is highly expressed in human liver and is known to metabolize more than 100 drugs. CYP2C8 substrate drugs include amodiaquine, cerivastatin, dasabuvir, enzalutamide, imatinib, loperamide, montelukast, paclitaxel, pioglitazone, repaglinide, and rosiglitazone, and the number is increasing. Similarly, many drugs have been identified as CYP2C8 inhibitors or inducers. In vivo, already a small dose of gemfibrozil, i.e., 10% of its therapeutic dose, is a strong, irreversible inhibitor of CYP2C8. Interestingly, recent findings indicate that the acyl-β-glucuronides of gemfibrozil and clopidogrel cause metabolism-dependent inactivation of CYP2C8, leading to a strong potential for drug interactions. Also several other glucuronide metabolites interact with CYP2C8 as substrates or inhibitors, suggesting that an interplay between CYP2C8 and glucuronides is common. Lack of fully selective and safe probe substrates, inhibitors, and inducers challenges execution and interpretation of drug-drug interaction studies in humans. Apart from drug-drug interactions, some CYP2C8 genetic variants are associated with altered CYP2C8 activity and exhibit significant interethnic frequency differences. Herein, we review the current knowledge on substrates, inhibitors, inducers, and pharmacogenetics of CYP2C8, as well as its role in clinically relevant drug interactions. In addition, implications for selection of CYP2C8 marker and perpetrator drugs to investigate CYP2C8-mediated drug metabolism and interactions in preclinical and clinical studies are discussed.
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Affiliation(s)
- Janne T Backman
- Department of Clinical Pharmacology, University of Helsinki (J.T.B., A.M.F., M.N., P.J.N.), and Helsinki University Hospital, Helsinki, Finland (J.T.B., M.N., P.J.N.)
| | - Anne M Filppula
- Department of Clinical Pharmacology, University of Helsinki (J.T.B., A.M.F., M.N., P.J.N.), and Helsinki University Hospital, Helsinki, Finland (J.T.B., M.N., P.J.N.)
| | - Mikko Niemi
- Department of Clinical Pharmacology, University of Helsinki (J.T.B., A.M.F., M.N., P.J.N.), and Helsinki University Hospital, Helsinki, Finland (J.T.B., M.N., P.J.N.)
| | - Pertti J Neuvonen
- Department of Clinical Pharmacology, University of Helsinki (J.T.B., A.M.F., M.N., P.J.N.), and Helsinki University Hospital, Helsinki, Finland (J.T.B., M.N., P.J.N.)
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The spleen as an extramedullary source of inflammatory cells responding to acetaminophen-induced liver injury. Toxicol Appl Pharmacol 2016; 304:110-20. [PMID: 27163765 DOI: 10.1016/j.taap.2016.04.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 04/25/2016] [Accepted: 04/27/2016] [Indexed: 12/18/2022]
Abstract
Macrophages have been shown to play a role in acetaminophen (APAP)-induced hepatotoxicity, contributing to both pro- and anti-inflammatory processes. In these studies, we analyzed the role of the spleen as an extramedullary source of hepatic macrophages. APAP administration (300mg/kg, i.p.) to control mice resulted in an increase in CD11b(+) infiltrating Ly6G(+) granulocytic and Ly6G(-) monocytic cells in the spleen and the liver. The majority of the Ly6G(+) cells were also positive for the monocyte/macrophage activation marker, Ly6C, suggesting a myeloid derived suppressor cell (MDSC) phenotype. By comparison, Ly6G(-) cells consisted of 3 subpopulations expressing high, intermediate, and low levels of Ly6C. Splenectomy was associated with increases in mature (F4/80(+)) and immature (F4/80(-)) pro-inflammatory Ly6C(hi) macrophages and mature anti-inflammatory (Ly6C(lo)) macrophages in the liver after APAP; increases in MDSCs were also noted in the livers of splenectomized (SPX) mice after APAP. This was associated with increases in APAP-induced expression of chemokine receptors regulating pro-inflammatory (CCR2) and anti-inflammatory (CX3CR1) macrophage trafficking. In contrast, APAP-induced increases in pro-inflammatory galectin-3(+) macrophages were blunted in livers of SPX mice relative to control mice, along with hepatic expression of TNF-α, as well as the anti-inflammatory macrophage markers, FIZZ-1 and YM-1. These data demonstrate that multiple subpopulations of pro- and anti-inflammatory cells respond to APAP-induced injury, and that these cells originate from distinct hematopoietic reservoirs.
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Shen G, Wang C, Zhou L, Li L, Chen H, Yu W, Li H. CYP450 Enzyme-Mediated Metabolism of TCAS and Its Inhibitory and Induced Effects on Metabolized Enzymes in Vitro. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2015; 12:10783-93. [PMID: 26404338 PMCID: PMC4586642 DOI: 10.3390/ijerph120910783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Revised: 08/17/2015] [Accepted: 08/18/2015] [Indexed: 11/18/2022]
Abstract
In this study, we investigated the enzymes catalyzing the phaseⅠmetabolism of thiacalixarene (TCAS) based on in vitro system including cDNA-expressed P450 enzymes, human liver microsomes plus inhibitors and monoclonal antibodies. In addition, the inhibitory potential of TCAS on major CYP450 drug metabolizing enzymes (CYP1A2, CYP2C9, CYP2B6, CYP2D6 and CYP3A4) was assessed. The results showed that CYP1A2 and CYP2C9 mediated TCAS hydroxylation. IC50 values for TCAS in rat and human liver microsomes were greater than 50 µM, and it demonstrated a weak inhibition of rat and human CYP450 enzymes. Finally, sandwiched hepatocytes were used to evaluate the induction of CYP1A and CYP3A to define the function of TCAS in vivo. The results showed that incubation of TCAS at different concentrations for 72 h failed to induce CYP1A and CYP3A. However, incubation of the cells with 50 and 100 µM TCAS caused a profound decrease in the activities of CYP1A and CYP3A, which was probably due to cytotoxic effects, suggesting that exposure to TCAS might be a health concern.
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Affiliation(s)
- Guolin Shen
- Chinese Academy of Inspection and Quarantine, Beijing 100123, China.
| | - Cheng Wang
- Chinese Academy of Inspection and Quarantine, Beijing 100123, China.
| | - Lili Zhou
- Chinese Academy of Inspection and Quarantine, Beijing 100123, China.
| | - Lei Li
- Chinese Academy of Inspection and Quarantine, Beijing 100123, China.
| | - Huiming Chen
- Chinese Academy of Inspection and Quarantine, Beijing 100123, China.
| | - Wenlian Yu
- Chinese Academy of Inspection and Quarantine, Beijing 100123, China.
| | - Haishan Li
- Chinese Academy of Inspection and Quarantine, Beijing 100123, China.
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Greenblatt DJ, Harmatz JS. Ritonavir is the best alternative to ketoconazole as an index inhibitor of cytochrome P450-3A in drug-drug interaction studies. Br J Clin Pharmacol 2015; 80:342-50. [PMID: 25923589 DOI: 10.1111/bcp.12668] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Revised: 04/23/2015] [Accepted: 04/24/2015] [Indexed: 12/16/2022] Open
Abstract
AIMS The regulatory prohibition of ketoconazole as a CYP3A index inhibitor in drug-drug interaction (DDI) studies has compelled consideration of alternative inhibitors. METHODS The biomedical literature was searched to identify DDI studies in which oral midazolam (MDZ) was the victim, and the inhibitory perpetrator was either ketoconazole, itraconazole, clarithromycin, or ritonavir. The ratios (RAUC ) of total area under the curve (AUC) for MDZ with inhibitor divided by MDZ AUC in the control condition were aggregated across individual studies for each inhibitor. RESULTS Mean (± SE) RAUC values were: ketoconazole (15 studies, 131 subjects), 11.5 (±1.2); itraconazole (five studies, 48 subjects), 7.3 (±1.0); clarithromycin (five studies, 73 subjects), 6.5 (±10.9); and ritonavir (13 studies, 159 subjects), 14.5 (±2.0). Differences among inhibitors were significant (F = 5.31, P < 0.005). RAUC values were not significantly related to inhibitor dosage or to duration of inhibitor pre-exposure prior to administration of MDZ. CONCLUSIONS Ritonavir produces CYP3A inhibition equivalent to or greater than ketoconazole, and is the best index CYP3A inhibitor alternative to ketoconazole. Cobicistat closely resembles ritonavir in structure and function, and can also be considered. Itraconazole and clarithromycin are not suitable alternatives since they do not produce inhibition comparable with ketoconazole or ritonavir, and have other significant disadvantages as well.
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Affiliation(s)
- David J Greenblatt
- From the Program in Pharmacology and Experimental Therapeutics, Tufts University School of Medicine and Sackler School of Graduate Biomedical Sciences, Boston, MA, USA
| | - Jerold S Harmatz
- From the Program in Pharmacology and Experimental Therapeutics, Tufts University School of Medicine and Sackler School of Graduate Biomedical Sciences, Boston, MA, USA
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Awortwe C, Bouic PJ, Masimirembwa CM, Rosenkranz B. Inhibition of major drug metabolizing CYPs by common herbal medicines used by HIV/AIDS patients in Africa-- implications for herb-drug interactions. Drug Metab Lett 2014; 7:83-95. [PMID: 24475926 PMCID: PMC4354708 DOI: 10.2174/1872312808666140129123210] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Revised: 12/03/2013] [Accepted: 01/25/2014] [Indexed: 11/22/2022]
Abstract
The purpose of this study was to evaluate the potential risk of common herbal medicines used by HIV-infected patients in Africa for herb-drug interactions (HDI). High throughput screening assays consisting of recombinant Cytochrome P450 enzymes (CYPs) and fluorescent probes, and parallel artificial membrane permeability assays (PAMPA) were used. The potential of herbal medicines to cause HDI was ranked according to FDA guidelines for reversible inhibition and categorization of time dependent inhibition was based on the normalized ratio. CYPs 1A2 and 3A4 were most inhibited by the herbal extracts. H. hemerocallidea (IC50 = 0.63 µg/mL and 58 µg/mL) and E. purpurea (IC50 = 20 µg/mL and 12 µg/mL) were the potent inhibitors of CYPs 1A2 and 3A4 respectively. L. frutescens and H. hemerocallidea showed clear time dependent inhibition on CYP3A4. Furthermore, the inhibitory effect of both H. hemerocallidea and L. frutescens before and after PAMPA were identical. The results indicate potential HDI of H. hemerocallidea, L. frutescens and E. purpurea with substrates of the affected enzymes if maximum in vivo concentration is achieved.
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Affiliation(s)
| | | | | | - Bernd Rosenkranz
- Division of Clinical Pharmacology, Department of Medicine, University of Stellenbosch, PO Box 19063, Tygerberg, Cape Town, 7505, South Africa.
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Ramasamy S, Kiew LV, Chung LY. Inhibition of human cytochrome P450 enzymes by Bacopa monnieri standardized extract and constituents. Molecules 2014; 19:2588-601. [PMID: 24566323 PMCID: PMC6271976 DOI: 10.3390/molecules19022588] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Revised: 02/19/2014] [Accepted: 02/19/2014] [Indexed: 11/16/2022] Open
Abstract
Bacopa monnieri and the constituents of this plant, especially bacosides, possess various neuropharmacological properties. Like drugs, some herbal extracts and the constituents of their extracts alter cytochrome P450 (CYP) enzymes, causing potential herb-drug interactions. The effects of Bacopa monnieri standardized extract and the bacosides from the extract on five major CYP isoforms in vitro were analyzed using a luminescent CYP recombinant human enzyme assay. B. monnieri extract exhibited non-competitive inhibition of CYP2C19 (IC50/Ki = 23.67/9.5 µg/mL), CYP2C9 (36.49/12.5 µg/mL), CYP1A2 (52.20/25.1 µg/mL); competitive inhibition of CYP3A4 (83.95/14.5 µg/mL) and weak inhibition of CYP2D6 (IC50 = 2061.50 µg/mL). However, the bacosides showed negligible inhibition of the same isoforms. B. monnieri, which is orally administered, has a higher concentration in the gut than the liver; therefore, this herb could exhibit stronger inhibition of intestinal CYPs than hepatic CYPs. At an estimated gut concentration of 600 µg/mL (based on a daily dosage of 300 mg/day), B. monnieri reduced the catalytic activities of CYP3A4, CYP2C9 and CYP2C19 to less than 10% compared to the total activity (without inhibitor = 100%). These findings suggest that B. monnieri extract could contribute to herb-drug interactions when orally co-administered with drugs metabolized by CYP1A2, CYP3A4, CYP2C9 and CYP2C19.
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Affiliation(s)
- Seetha Ramasamy
- Department of Pharmacy, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia.
| | - Lik Voon Kiew
- Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia.
| | - Lip Yong Chung
- Department of Pharmacy, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia.
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Björklund E, Larsson TNL, Jacobsson SOP, Fowler CJ. Ketoconazole inhibits the cellular uptake of anandamide via inhibition of FAAH at pharmacologically relevant concentrations. PLoS One 2014; 9:e87542. [PMID: 24466356 PMCID: PMC3900727 DOI: 10.1371/journal.pone.0087542] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Accepted: 12/21/2013] [Indexed: 12/20/2022] Open
Abstract
Background The antifungal compound ketoconazole has, in addition to its ability to interfere with fungal ergosterol synthesis, effects upon other enzymes including human CYP3A4, CYP17, lipoxygenase and thromboxane synthetase. In the present study, we have investigated whether ketoconazole affects the cellular uptake and hydrolysis of the endogenous cannabinoid receptor ligand anandamide (AEA). Methodology/Principal Findings The effects of ketoconazole upon endocannabinoid uptake were investigated using HepG2, CaCo2, PC-3 and C6 cell lines. Fatty acid amide hydrolase (FAAH) activity was measured in HepG2 cell lysates and in intact C6 cells. Ketoconazole inhibited the uptake of AEA by HepG2 cells and CaCo2 cells with IC50 values of 17 and 18 µM, respectively. In contrast, it had modest effects upon AEA uptake in PC-3 cells, which have a low expression of FAAH. In cell-free HepG2 lysates, ketoconazole inhibited FAAH activity with an IC50 value (for the inhibitable component) of 34 µM. Conclusions/Significance The present study indicates that ketoconazole can inhibit the cellular uptake of AEA at pharmacologically relevant concentrations, primarily due to its effects upon FAAH. Ketoconazole may be useful as a template for the design of dual-action FAAH/CYP17 inhibitors as a novel strategy for the treatment of prostate cancer.
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Affiliation(s)
- Emmelie Björklund
- Department of Pharmacology and Clinical Neuroscience, Umeå University, Umeå, Sweden
| | | | - Stig O. P. Jacobsson
- Department of Pharmacology and Clinical Neuroscience, Umeå University, Umeå, Sweden
| | - Christopher J. Fowler
- Department of Pharmacology and Clinical Neuroscience, Umeå University, Umeå, Sweden
- * E-mail:
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Chiu NTC, Guns EST, Adomat H, Jia W, Deb S. Identification of human cytochrome P450 enzymes involved in the hepatic and intestinal biotransformation of 20(S)-protopanaxadiol. Biopharm Drug Dispos 2013; 35:104-18. [DOI: 10.1002/bdd.1873] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Revised: 09/10/2013] [Accepted: 10/09/2013] [Indexed: 11/11/2022]
Affiliation(s)
- Nga Ting Colette Chiu
- Department of Pathology and Laboratory Science; University of British Columbia; Vancouver BC Canada
| | - Emma S. Tomlinson Guns
- The Vancouver Prostate Centre at Vancouver General Hospital; 2660 Oak Street Vancouver BC Canada V6H 3Z6
| | - Hans Adomat
- The Vancouver Prostate Centre at Vancouver General Hospital; 2660 Oak Street Vancouver BC Canada V6H 3Z6
| | - William Jia
- Department of Surgery; University of British Columbia; Vancouver BC Canada
| | - Subrata Deb
- The Vancouver Prostate Centre at Vancouver General Hospital; 2660 Oak Street Vancouver BC Canada V6H 3Z6
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Pivotal role of P450-P450 interactions in CYP3A4 allostery: the case of α-naphthoflavone. Biochem J 2013; 453:219-30. [PMID: 23651100 DOI: 10.1042/bj20130398] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
We investigated the relationship between oligomerization of CYP3A4 (cytochrome P450 3A4) and its response to ANF (α-naphthoflavone), a prototypical heterotropic activator. The addition of ANF resulted in over a 2-fold increase in the rate of CYP3A4-dependent debenzylation of 7-BFC [7-benzyloxy-4-(trifluoromethyl)coumarin] in HLM (human liver microsomes), but failed to produce activation in BD Supersomes or Baculosomes containing recombinant CYP3A4 and NADPH-CPR (cytochrome P450 reductase). However, incorporation of purified CYP3A4 into Supersomes containing only recombinant CPR reproduced the behaviour observed with HLM. The activation in this system was dependent on the surface density of the enzyme. Although no activation was detectable at an L/P (lipid/P450) ratio ≥750, it reached 225% at an L/P ratio of 140. To explore the relationship between this effect and CYP3A4 oligomerization, we probed P450-P450 interactions with a new technique that employs LRET (luminescence resonance energy transfer). The amplitude of LRET in mixed oligomers of the haem protein labelled with donor and acceptor fluorophores exhibited a sigmoidal dependence on the surface density of CYP3A4 in Supersomes™. The addition of ANF eliminated this sigmoidal character and increased the degree of oligomerization at low enzyme concentrations. Therefore the mechanisms of CYP3A4 allostery with ANF involve effector-dependent modulation of P450-P450 interactions.
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20
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Nesnow S. Integration of toxicological approaches with “omic” and related technologies to elucidate mechanisms of carcinogenic action: Propiconazole, an example. Cancer Lett 2013. [DOI: 10.1016/j.canlet.2012.11.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Ong CE, Pan Y, Mak JW, Ismail R. In vitro approaches to investigate cytochrome P450 activities: update on current status and their applicability. Expert Opin Drug Metab Toxicol 2013; 9:1097-113. [PMID: 23682848 DOI: 10.1517/17425255.2013.800482] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION Cytochromes P450 (CYPs) play a central role in the Phase I metabolism of drugs and other xenobiotics. It is estimated that CYPs can metabolize up to two-thirds of drugs present in humans. Over the past two decades, there have been numerous advances in in vitro methodologies to characterize drug metabolism and interaction involving CYPs. AREAS COVERED This review focuses on the use of in vitro methodologies to examine CYPs' role in drug metabolism and interaction. There is an emphasis on their current development, applicability, advantages and limitations as well as the use of in silico approaches in complementing and supporting in vitro data. The article also highlights the challenges in extrapolating in vitro data to in vivo situations. EXPERT OPINION Advances in in vitro methodologies have been made such that data can be used for in vivo prediction with comfortable degree of confidence. Improved assay designs and analytical techniques have permitted development of miniaturized assay format and automated system with improved sensitivity and throughput capacity. High-quality experimental designs and scientifically rigorous assessment/validation protocols remain crucial in developing reliable and robust in vitro models. With continued progress made in the field, in vitro methodologies will continually be employed in evaluating CYP activities in pharmaceutical industries and laboratories.
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Affiliation(s)
- Chin Eng Ong
- Monash University Sunway Campus, Jeffrey Cheah School of Medicine and Health Sciences, Jalan Lagoon Selatan, 46150 Bandar Sunway, Selangor, Malaysia.
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22
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Gelboin HV, Krausz K. Monoclonal Antibodies and Multifunctional Cytochrome P450: Drug Metabolism as Paradigm. J Clin Pharmacol 2013; 46:353-72. [PMID: 16490812 DOI: 10.1177/0091270005285200] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Monoclonal antibodies are reagents par excellence for analyzing the role of individual cytochrome P450 isoforms in multifunctional biological activities catalyzed by cytochrome P450 enzymes. The precision and utility of the monoclonal antibodies have heretofore been applied primarily to studies of human drug metabolism. The unique and precise specificity and high inhibitory activity toward individual cytochrome P450s make the monoclonal antibodies extraordinary tools for identifying and quantifying the role of each P450 isoform in the metabolism of a drug or nondrug xenobiotic. The monoclonal antibodies identify drugs metabolized by individual, several, or polymorphic P450s. A comprehensive collection of monoclonal antibodies has been isolated to human P450s: 1A1, 1A2, 2A6, 2B6, 2C8, 2C9, 2C family, 2C19, 2D6, 2E1, 3A4/5, and 2J2. The monoclonal antibodies can also be used for identifying drugs and/or metabolites useful as markers for in vivo phenotyping. Clinical identification of a patient's phenotype, coupled with precise knowledge of a drug's metabolism, should lead to a reduction of adverse drug reactions and improved drug therapeutics, thereby promoting advances in drug discovery.
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Affiliation(s)
- Harry V Gelboin
- Laboratory of Metabolism, National Institutes of Health, Building 37, Room 3106, Bethesda, MD 20892-0001, USA
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Gardner CR, Hankey P, Mishin V, Francis M, Yu S, Laskin JD, Laskin DL. Regulation of alternative macrophage activation in the liver following acetaminophen intoxication by stem cell-derived tyrosine kinase. Toxicol Appl Pharmacol 2012; 262:139-48. [PMID: 22575169 DOI: 10.1016/j.taap.2012.04.027] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Revised: 04/12/2012] [Accepted: 04/23/2012] [Indexed: 01/20/2023]
Abstract
Stem cell-derived tyrosine kinase (STK) is a transmembrane receptor reported to play a role in macrophage switching from a classically activated/proinflammatory phenotype to an alternatively activated/wound repair phenotype. In the present studies, STK⁻/⁻ mice were used to assess the role of STK in acetaminophen-induced hepatotoxicity as evidence suggests that the pathogenic process involves both of these macrophage subpopulations. In wild type mice, centrilobular hepatic necrosis and increases in serum transaminase levels were observed within 6h of acetaminophen administration (300 mg/kg, i.p.). Loss of STK resulted in a significant increase in sensitivity of mice to the hepatotoxic effects of acetaminophen and increased mortality, effects independent of its metabolism. This was associated with reduced levels of hepatic glutathione, rapid upregulation of inducible nitric oxide synthase, and prolonged induction of heme oxygenase-1, suggesting excessive oxidative stress in STK⁻/⁻ mice. F4/80, a marker of mature macrophages, was highly expressed on subpopulations of Kupffer cells in livers of wild type, but not STK⁻/⁻ mice. Whereas F4/80⁺ macrophages rapidly declined in the livers of wild type mice following acetaminophen intoxication, they increased in STK⁻/⁻ mice. In wild type mice hepatic expression of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-12, products of classically activated macrophages, increased after acetaminophen administration. Monocyte chemotactic protein-1 (MCP-1) and its receptor, CCR2, as well as IL-10, mediators involved in recruiting and activating anti-inflammatory/wound repair macrophages, also increased in wild type mice after acetaminophen. Loss of STK blunted the effects of acetaminophen on expression of TNFα, IL-1β, IL-12, MCP-1 and CCR2, while expression of IL-10 increased. Hepatic expression of CX3CL1, and its receptor, CX3CR1 also increased in STK⁻/⁻ mice treated with acetaminophen. These data demonstrate that STK plays a role in regulating macrophage recruitment and activation in the liver following acetaminophen administration, and in hepatotoxicity.
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Affiliation(s)
- Carol R Gardner
- Department of Pharmacology and Toxicology, Rutgers University, Ernest Mario School of Pharmacy, Piscataway, NJ 08854, USA.
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Huang L, Chen A, Roberts J, Janosky B, Be X, Berry L, Lin MHJ. Use of uptake intrinsic clearance from attached rat hepatocytes to predict hepatic clearance for poorly permeable compounds. Xenobiotica 2012; 42:830-40. [DOI: 10.3109/00498254.2012.667847] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Nesnow S, Grindstaff RD, Lambert G, Padgett WT, Bruno M, Ge Y, Chen PJ, Wood CE, Murphy L. Propiconazole increases reactive oxygen species levels in mouse hepatic cells in culture and in mouse liver by a cytochrome P450 enzyme mediated process. Chem Biol Interact 2011; 194:79-89. [DOI: 10.1016/j.cbi.2011.08.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Revised: 08/04/2011] [Accepted: 08/05/2011] [Indexed: 01/14/2023]
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Ozkor MA, Quyyumi AA. Endothelium-derived hyperpolarizing factor and vascular function. Cardiol Res Pract 2011; 2011:156146. [PMID: 21876822 PMCID: PMC3157651 DOI: 10.4061/2011/156146] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Revised: 05/27/2011] [Accepted: 05/27/2011] [Indexed: 01/20/2023] Open
Abstract
Endothelial function refers to a multitude of physiological processes that maintain healthy homeostasis of the vascular wall. Exposure of the endothelium to cardiac risk factors results in endothelial dysfunction and is associated with an alteration in the balance of vasoactive substances produced by endothelial cells. These include a reduction in nitric oxide (NO), an increase in generation of potential vasoconstrictor substances and a potential compensatory increase in other mediators of vasodilation. The latter has been surmised from data demonstrating persistent endothelium-dependent vasodilatation despite complete inhibition of NO and prostaglandins. This remaining non-NO, non-prostaglandin mediated endothelium-dependent vasodilator response has been attributed to endothelium-derived hyperpolarizing factor/s (EDHF). Endothelial hyperpolarization is likely due to several factors that appear to be site and species specific. Experimental studies suggest that the contribution of the EDHFs increase as the vessel size decreases, with a predominance of EDHF activity in the resistance vessels, and a compensatory up-regulation of hyperpolarization in states characterized by reduced NO availability. Since endothelial dysfunction is a precursor for atherosclerosis development and its magnitude is a reflection of future risk, then the mechanisms underlying endothelial dysfunction need to be fully understood, so that adequate therapeutic interventions can be designed.
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Affiliation(s)
- Muhiddin A Ozkor
- The Heart Hospital, University College London, London WIG 8PH, UK
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Hong H, Su H, Ma L, Yao M, Iyer RA, Humphreys WG, Christopher LJ. In vitro characterization of the metabolic pathways and cytochrome P450 inhibition and induction potential of BMS-690514, an ErbB/vascular endothelial growth factor receptor inhibitor. Drug Metab Dispos 2011; 39:1658-67. [PMID: 21673131 DOI: 10.1124/dmd.111.039776] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
(3R,4R)-4-Amino-1-((4-((3-methoxyphenyl)amino)pyrrolo[2,1-f][1,2,4]triazin-5-yl)methyl)-3-piperidinol (BMS-690514) is a potent inhibitor of ErbB human epidermal growth factor receptors (HER1, 2, and 4) and vascular endothelial growth factor receptors 1 to 3 that has been under clinical development for solid tumor malignancies. BMS-690514 is primarily cleared by metabolism with the primary metabolic pathways being direct glucuronidation (M6), hydroxylation (M1, M2, and M37), and O-demethylation (M3). In the current investigation, the metabolic drug-drug interaction potential of BMS-690514 was evaluated in a series of in vitro studies. Reaction phenotyping experiments with cDNA-expressed human cytochrome P450 (P450) and UDP-glucuronosyltransferase (UGT) enzymes and human liver microsomes (HLM) in the presence of P450 or UGT inhibitors suggested that CYP3A4, CYP2D6, and CYP2C9 were the major enzymes responsible for the oxidative metabolism of BMS-690514, whereas both UGT2B4 and UGT2B7 were responsible for the formation of M6. BMS-690514 did not cause direct or time-dependent inhibition of P450 enzymes (IC(50) values ≥40 μM) in incubations with HLM and probe substrates of CYP1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, or 3A4. The compound also did not substantially induce CYP1A1, CYP1A2, CYP2B6, CYP3A4, or UGT1A1 at concentrations up to 10 μM in cultured human hepatocytes. Considering the submicromolar plasma C(max) concentration at the anticipated clinical dose of 200 mg, BMS-690514 is unlikely to cause clinically relevant drug-drug interactions when coadministered with other medications. In addition, because multiple enzymatic clearance pathways are available for the compound, inhibition of an individual metabolic pathway either via coadministered drugs or gene polymorphisms is not expected to cause pronounced (>2-fold) increases in BMS-690514 exposure.
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Affiliation(s)
- Haizheng Hong
- Department of Biotransformation, Pharmaceutical Candidate Optimization, Bristol-Myers Squibb Research, Route 206 and Province Line Rd., Princeton, NJ 08543, USA
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Marks KM, Park ES, Arefolov A, Russo K, Ishihara K, Ring JE, Clardy J, Clarke AS, Pelish HE. The selectivity of austocystin D arises from cell-line-specific drug activation by cytochrome P450 enzymes. JOURNAL OF NATURAL PRODUCTS 2011; 74:567-573. [PMID: 21348461 PMCID: PMC3081663 DOI: 10.1021/np100429s] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2010] [Indexed: 05/30/2023]
Abstract
The natural product austocystin D was identified as a potent cytotoxic agent with in vivo antitumor activity and selectivity for cells expressing the multidrug resistance transporter MDR1. We sought to elucidate the mechanism of austocystin D's selective cytotoxic activity. Here we show that the selective cytotoxic action of austocystin D arises from its selective activation by cytochrome P450 (CYP) enzymes in specific cancer cell lines, leading to induction of DNA damage in cells and in vitro. The potency and selectivity of austocystin D is lost upon inhibition of CYP activation and does not require MDR1 expression or activity. Furthermore, the pattern of cytotoxicity of austocystin D was distinct from doxorubicin and etoposide and unlike aflatoxin B(1), a compound that resembles austocystin D and is also activated by CYP enzymes to induce DNA damage. Theses results suggest that austocystin D may be of clinical benefit for targeting or overcoming chemoresistance.
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Affiliation(s)
- Kevin M. Marks
- Makoto Life Sciences, Inc., 15 DeAngelo Drive, Bedford, Massachusetts 01730, United States
| | - Eun Sun Park
- Makoto Life Sciences, Inc., 15 DeAngelo Drive, Bedford, Massachusetts 01730, United States
| | - Alexander Arefolov
- Makoto Life Sciences, Inc., 15 DeAngelo Drive, Bedford, Massachusetts 01730, United States
| | - Katie Russo
- Makoto Life Sciences, Inc., 15 DeAngelo Drive, Bedford, Massachusetts 01730, United States
| | - Keiko Ishihara
- Makoto Life Sciences, Inc., 15 DeAngelo Drive, Bedford, Massachusetts 01730, United States
- Taiho Pharmaceutical Co., LTD., 3 Okubo, Tsukuba, Ibaraki 300-2611, Japan
| | - Jennifer E. Ring
- Makoto Life Sciences, Inc., 15 DeAngelo Drive, Bedford, Massachusetts 01730, United States
| | - Jon Clardy
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Avenue, Boston, Massachusetts 02115, United States
| | - Astrid S. Clarke
- Makoto Life Sciences, Inc., 15 DeAngelo Drive, Bedford, Massachusetts 01730, United States
| | - Henry E. Pelish
- Makoto Life Sciences, Inc., 15 DeAngelo Drive, Bedford, Massachusetts 01730, United States
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Peng CC, Templeton I, Thummel KE, Davis C, Kunze KL, Isoherranen N. Evaluation of 6β-hydroxycortisol, 6β-hydroxycortisone, and a combination of the two as endogenous probes for inhibition of CYP3A4 in vivo. Clin Pharmacol Ther 2011; 89:888-95. [PMID: 21490593 DOI: 10.1038/clpt.2011.53] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
An endogenous probe for CYP3A activity would be useful for early identification of in vivo cytochrome P450 (CYP) 3A4 inhibitors. The aim of this study was to determine whether formation clearance (CL(f)) of the sum of 6β-hydroxycortisol and 6β-hydroxycortisone is a useful probe of CYP3A4 inhibition in vivo. In human liver microsomes (HLMs), the formation of 6β-hydroxycortisol and 6β-hydroxycortisone was catalyzed by CYP3A4, and itraconazole inhibited these reactions with half maximal inhibitory concentration (IC(50))(,u) values of 3.1 nmol/l and 3.4 nmol/l, respectively. The in vivo IC(50,u) value of itraconazole for the combined CL(f) of 6β-hydroxycortisone and 6β-hydroxycortisol was 1.6 nmol/l. The greater inhibitory potency in vivo is probably due to circulating inhibitory itraconazole metabolites. The maximum in vivo inhibition was 59%, suggesting that f(m,CYP3A4) for cortisol and cortisone 6β-hydroxylation is ~60%. Given the significant decrease in CL(f) of 6β-hydroxycortisone and 6β-hydroxycortisol after 200-mg and 400-mg single doses of itraconazole, this endogenous probe can be used to detect moderate and potent CYP3A4 inhibition in vivo.
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Affiliation(s)
- C-C Peng
- Department of Pharmaceutics, University of Washington School of Pharmacy, Seattle, Washington, USA
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Chemical inhibitors of cytochrome P450 isoforms in human liver microsomes: a re-evaluation of P450 isoform selectivity. Eur J Drug Metab Pharmacokinet 2011; 36:1-16. [PMID: 21336516 DOI: 10.1007/s13318-011-0024-2] [Citation(s) in RCA: 111] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2010] [Accepted: 02/01/2011] [Indexed: 01/24/2023]
Abstract
The majority of marketed small-molecule drugs undergo metabolism by hepatic Cytochrome P450 (CYP) enzymes (Rendic 2002). Since these enzymes metabolize a structurally diverse number of drugs, metabolism-based drug-drug interactions (DDIs) can potentially occur when multiple drugs are coadministered to patients. Thus, a careful in vitro assessment of the contribution of various CYP isoforms to the total metabolism is important for predicting whether such DDIs might take place. One method of CYP phenotyping involves the use of potent and selective chemical inhibitors in human liver microsomal incubations in the presence of a test compound. The selectivity of such inhibitors plays a critical role in deciphering the involvement of specific CYP isoforms. Here, we review published data on the potency and selectivity of chemical inhibitors of the major human hepatic CYP isoforms. The most selective inhibitors available are furafylline (in co-incubation and pre-incubation conditions) for CYP1A2, 2-phenyl-2-(1-piperidinyl)propane (PPP) for CYP2B6, montelukast for CYP2C8, sulfaphenazole for CYP2C9, (-)-N-3-benzyl-phenobarbital for CYP2C19 and quinidine for CYP2D6. As for CYP2A6, tranylcypromine is the most widely used inhibitor, but on the basis of initial studies, either 3-(pyridin-3-yl)-1H-pyrazol-5-yl)methanamine (PPM) and 3-(2-methyl-1H-imidazol-1-yl)pyridine (MIP) can replace tranylcypromine as the most selective CYP2A6 inhibitor. For CYP3A4, ketoconazole is widely used in phenotyping studies, although azamulin is a far more selective CYP3A inhibitor. Most of the phenotyping studies do not include CYP2E1, mostly because of the limited number of new drug candidates that are metabolized by this enzyme. Among the inhibitors for this enzyme, 4-methylpyrazole appears to be selective.
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Nishimuta H, Sato K, Mizuki Y, Yabuki M, Komuro S. Prediction of the Intestinal First-Pass Metabolism of CYP3A Substrates in Humans Using Cynomolgus Monkeys. Drug Metab Dispos 2010; 38:1967-75. [DOI: 10.1124/dmd.110.034561] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Zhou L, Naraharisetti SB, Liu L, Wang H, Lin YS, Isoherranen N, Unadkat JD, Hebert MF, Mao Q. Contributions of human cytochrome P450 enzymes to glyburide metabolism. Biopharm Drug Dispos 2010; 31:228-42. [PMID: 20437462 DOI: 10.1002/bdd.706] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Glyburide (GLB) is a widely used oral sulfonylurea for the treatment of gestational diabetes. The therapeutic use of GLB is often complicated by a substantial inter-individual variability in the pharmacokinetics and pharmacodynamics of the drug in human populations, which might be caused by inter-individual variations in factors such as GLB metabolism. Therefore, there has been a continued interest in identifying human cytochrome P450 (CYP) isoforms that play a major role in the metabolism of GLB. However, contrasting data are available in the present literature in this regard. The present study systematically investigated the contributions of various human CYP isoforms (CYP3A4, CYP3A5, CYP2C8, CYP2C9 and CYP2C19) to in vitro metabolism of GLB. GLB depletion and metabolite formation in human liver microsomes were most significantly inhibited by the CYP3A inhibitor ketoconazole compared with the inhibitors of other CYP isoforms. Furthermore, multiple correlation analysis between GLB depletion and individual CYP activities was performed, demonstrating a significant correlation between GLB depletion and the CYP3A probe activity in 16 individual human liver microsomal preparations, but not between GLB depletion and the CYP2C19, CYP2C8 or CYP2C9 probe activity. By using recombinant supersomes overexpressing individual human CYP isoforms, it was found that GLB could be depleted by all the enzymes tested; however, the intrinsic clearance (V(max)/K(m)) of CYP3A4 for GLB depletion was 4-17 times greater than that of other CYP isoforms. These results confirm that human CYP3A4 is the major enzyme involved in the in vitro metabolism of GLB.
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Affiliation(s)
- Lin Zhou
- Department of Pharmaceutics, School of Pharmacy, University of Washington, Seattle, WA 98195, USA
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Seneca N, Zoghbi SS, Shetty HU, Tuan E, Kannan P, Taku A, Innis RB, Pike VW. Effects of ketoconazole on the biodistribution and metabolism of [11C]loperamide and [11C]N-desmethyl-loperamide in wild-type and P-gp knockout mice. Nucl Med Biol 2010; 37:335-45. [PMID: 20346873 PMCID: PMC2847595 DOI: 10.1016/j.nucmedbio.2009.12.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2009] [Revised: 12/01/2009] [Accepted: 12/28/2009] [Indexed: 12/27/2022]
Abstract
INTRODUCTION [(11)C]Loperamide and [(11)C]N-desmethyl-loperamide ([(11)C]dLop) have been proposed as radiotracers for imaging brain P-glycoprotein (P-gp) function. A major route of [(11)C]loperamide metabolism is N-demethylation to [(11)C]dLop. We aimed to test whether inhibition of CYP3A4 with ketoconazole might reduce the metabolism of [(11)C]loperamide and [(11)C]dLop in mice, and thereby improve the quality of these radiotracers. METHODS Studies were performed in wild-type and P-gp knockout (mdr-1a/b -/-) mice. During each of seven study sessions, one pair of mice, comprising one wild-type and one knockout mouse, was pretreated with ketoconazole (50 mg/kg, ip), while another such pair was left untreated. Mice were sacrificed at 30 min after injection of [(11)C]loperamide or [(11)C]dLop. Whole brain and plasma samples were measured for radioactivity and analyzed with radio-high-performance liquid chromatography. RESULTS Ketoconazole increased the plasma concentrations of [(11)C]loperamide and its main radiometabolite, [(11)C]dLop, by about twofold in both wild-type and knockout mice, whereas the most polar radiometabolite was decreased threefold. Furthermore, ketoconazole increased the brain concentrations of [(11)C]loperamide and the radiometabolite [(11)C]dLop by about twofold in knockout mice, and decreased the brain concentrations of the major and most polar radiometabolite in wild-type and knockout mice by 82% and 49%, respectively. In contrast, ketoconazole had no effect on plasma and brain distribution of administered [(11)C]dLop and its radiometabolites in either wild-type or knockout mice, except to increase the low plasma [(11)C]dLop concentration. The least polar radiometabolite of [(11)C]dLop was identified with LC-MS(n) as the N-hydroxymethyl analog of [(11)C]dLop and this also behaved as a P-gp substrate. CONCLUSION In this study, ketoconazole (50 mg/kg, ip) proved partially effective for inhibiting the N-demethylation of [(11)C]loperamide in mouse in vivo but had relatively smaller or no effect on [(11)C]dLop.
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Affiliation(s)
- Nicholas Seneca
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA
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Hagemeyer CE, Bürck C, Schwab R, Knoth R, Meyer RP. 7-Benzyloxyresorufin-O-dealkylase activity as a marker for measuring cytochrome P450 CYP3A induction in mouse liver. Anal Biochem 2010; 398:104-11. [DOI: 10.1016/j.ab.2009.11.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2009] [Revised: 11/02/2009] [Accepted: 11/04/2009] [Indexed: 01/10/2023]
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Dagliyan O, Kavakli IH, Turkay M. Classification of cytochrome P450 inhibitors with respect to binding free energy and pIC50 using common molecular descriptors. J Chem Inf Model 2009; 49:2403-11. [PMID: 19777996 DOI: 10.1021/ci900247t] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Virtual screening of chemical libraries following experimental assays of drug candidates is a common procedure in structure based drug discovery. However, the relationship between binding free energies and biological activities (pIC50) of drug candidates is still an unsolved issue that limits the efficiency and speed of drug development processes. In this study, the relationship between them is investigated based on a common molecular descriptor set for human cytochrome P450 enzymes (CYPs). CYPs play an important role in drug-drug interactions, drug metabolism, and toxicity. Therefore, in silico prediction of CYP inhibition by drug candidates is one of the major considerations in drug discovery. The combination of partial least-squares regression (PLSR) and a variety of classification algorithms were employed by considering this relationship as a classification problem. Our results indicate that PLSR with classification is a powerful tool to predict more than one output such as binding free energy and pIC50 simultaneously. PLSR with mixed-integer linear programming based hyperboxes predicts the binding free energy and pIC50 with a mean accuracy of 87.18% (min: 81.67% max: 97.05%) and 88.09% (min: 79.83% max: 92.90%), respectively, for the cytochrome p450 superfamily using the common 6 molecular descriptors with a 10-fold cross-validation.
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Affiliation(s)
- Onur Dagliyan
- Department of Chemical and Biological Engineering, College of Engineering and Center for Computational Biology and Bioinformatics, Koç University, Rumelifeneri yolu, Sariyer, Istanbul, 34450 Turkey
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Kot M, A. Daniel W. Effect of diethyldithiocarbamate (DDC) and ticlopidine on CYP1A2 activity and caffeine metabolism: an in vitro comparative study with human cDNA-expressed CYP1A2 and liver microsomes. Pharmacol Rep 2009; 61:1216-20. [DOI: 10.1016/s1734-1140(09)70187-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2009] [Revised: 11/05/2009] [Indexed: 10/25/2022]
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Zharikova OL, Fokina VM, Nanovskaya TN, Hill RA, Mattison DR, Hankins GDV, Ahmed MS. Identification of the major human hepatic and placental enzymes responsible for the biotransformation of glyburide. Biochem Pharmacol 2009; 78:1483-90. [PMID: 19679108 DOI: 10.1016/j.bcp.2009.08.003] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2009] [Revised: 07/31/2009] [Accepted: 08/04/2009] [Indexed: 02/01/2023]
Abstract
One of the factors affecting the pharmacokinetics (PK) of a drug during pregnancy is the activity of hepatic and placental metabolizing enzymes. Recently, we reported on the biotransformation of glyburide by human hepatic and placental microsomes to six metabolites that are structurally identical between the two tissues. Two of the metabolites, 4-trans-(M1) and 3-cis-hydroxycyclohexyl glyburide (M2b), were previously identified in plasma and urine of patients treated with glyburide and are pharmacologically active. The aim of this investigation was to identify the major human hepatic and placental CYP450 isozymes responsible for the formation of each metabolite of glyburide. This was achieved by the use of chemical inhibitors selective for individual CYP isozymes and antibodies raised against them. The identification was confirmed by the kinetic constants for the biotransformation of glyburide by cDNA-expressed enzymes. The data revealed that the major hepatic isozymes responsible for the formation of each metabolite are as follows: CYP3A4 (ethylene-hydroxylated glyburide (M5), 3-trans-(M3) and 2-trans-(M4) cyclohexyl glyburide); CYP2C9 (M1, M2a (4-cis-) and M2b); CYP2C8 (M1 and M2b); and CYP2C19 (M2a). Human placental microsomal CYP19/aromatase was the major isozyme responsible for the biotransformation of glyburide to predominantly M5. The formation of significant amounts of M5 by CYP19 in the placenta could render this metabolite more accessible to the fetal circulation. The multiplicity of enzymes biotransforming glyburide and the metabolites formed underscores the potential for its drug interactions in vivo.
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Affiliation(s)
- Olga L Zharikova
- Department of Obstetrics & Gynecology, University of Texas Medical Branch, Galveston, TX, 77555-0587, USA
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Toda T, Eliasson E, Ask B, Inotsume N, Rane A. Roles of different CYP enzymes in the formation of specific fluvastatin metabolites by human liver microsomes. Basic Clin Pharmacol Toxicol 2009; 105:327-32. [PMID: 19663817 DOI: 10.1111/j.1742-7843.2009.00453.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Fluvastatin has been considered to be metabolised to 5-hydroxy fluvastatin (M-2), 6-hydroxy fluvastatin (M-3) and N-desisopropyl fluvastatin (M-5) in human liver microsomes by primarily CYP2C9. To elucidate the contribution of different CYP enzymes on fluvastatin metabolism, we examined the effect of CYP inhibitors and CYP2C-specific monoclonal antibodies on the formation of fluvastatin metabolites in human liver microsomes. Human liver microsomes were incubated with fluvastatin with or without pre-treatment with CYP inhibitors or monoclonal antibodies. Selective inhibitors of CYP2C9 (sulfaphenazole), CYP3A (ketoconazole) and CYP2C8 (quercetin) were employed and monoclonal antibodies were against CYP2C8, CYP2C9, CYP2C19 and CYP2C8/9/18/19. According to the amount of fluvastatin metabolites produced, the formation of M-3 was found to be major pathway of fluvastatin metabolism (the relative contribution was calculated to be more than 80%). Sulfaphenazole inhibited the formation of M-2 largely, but had little effect on the formation of M-3. It also inhibited the formation of M-5. Ketoconazole markedly inhibited the formation of M-3, but did not inhibit the formation of M-2 and M-5. Quercetin had a moderate inhibitory effect on the formation of all three fluvastatin metabolites. Monoclonal antibodies against CYP2C9 and CYP2C8/9/18/19 markedly inhibited the formation of M-2 and M-5. None of monoclonal antibodies showed clear inhibition on the formation of M-3. In contrast to previous published work, our results suggest that M-2 and M-5 are formed preferentially by CYP2C9, and that M-3 is mainly formed by CYP3A. In summary, the results contribute to a better understanding of the drug-drug interaction potential for fluvastatin in vivo.
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Affiliation(s)
- Takaki Toda
- Division of Clinical Pharmacology, Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
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Meyer RP, Gehlhaus M, Schwab R, Bürck C, Knoth R, Hagemeyer CE. Concordant up-regulation of cytochrome P450 Cyp3a11, testosterone oxidation and androgen receptor expression in mouse brain after xenobiotic treatment. J Neurochem 2009; 109:670-81. [DOI: 10.1111/j.1471-4159.2009.05994.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Giannarelli C, Virdis A, De Negri F, Magagna A, Duranti E, Salvetti A, Taddei S. Effect of sulfaphenazole on tissue plasminogen activator release in normotensive subjects and hypertensive patients. Circulation 2009; 119:1625-33. [PMID: 19289643 DOI: 10.1161/circulationaha.108.782482] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND A nitric oxide-independent response, possibly mediated by hyperpolarization, regulates vascular tone, acting as a compensatory mechanism in the presence of impaired nitric oxide availability. Cytochrome P450 2C9 (CYP 2C9) is a source of endothelium-derived hyperpolarizing factors and modulates tissue-type plasminogen activator (tPA) release from endothelial cells; however, no effect of hyperpolarization on fibrinolysis has been documented in humans. We aimed to assess the effect of sulfaphenazole, a specific CYP 2C9 inhibitor, on tPA release in normotensive subjects and patients with essential hypertension. METHODS AND RESULTS tPA release was measured in the forearm microcirculation of 56 normotensivesubjects and 57 patients with essential hypertension after bradykinin (0.015 microg x 100 mL(-1) x min(-1)) and acetylcholine (1.5 microg x 100 mL(-1) x min(-1)) infusions, with or without sulfaphenazole (0.03 microg x 100 mL(-1) x min(-1)). Bradykinin and acetylcholine infusions were repeated with N(G)-monomethyl-l-arginine (L-NMMA; 100 microg x 100 mL(-1) x min(-1)) and/or sulfaphenazole. tPA release by bradykinin and acetylcholine was higher in normotensive subjects than in patients with essential hypertension (P<0.01). Sulfaphenazole (P<0.01) blunted bradykinin-induced but not acetylcholine-induced tPA release in both groups. In normotensive subjects, L-NMMA infusion reduced tPA release (P<0.01). When L-NMMA was coinfused with sulfaphenazole, tPA release induced by bradykinin, but not by acetylcholine, was further reduced (P<0.01). In patients with essential hypertension, tPA release by both agonists was unaffected by L-NMMA, but only bradykinin-induced tPA release was blunted by sulfaphenazole, alone or with L-NMMA (P<001). CONCLUSIONS Sulfaphenazole inhibits bradykinin-induced tPA release, which suggests a modulatory role of CYP 2C9-derived endothelium-derived hyperpolarizing factors in tPA release in humans. In patients with essential hypertension, tPA release depends exclusively on endothelium-derived hyperpolarizing factor, which is an ineffective compensatory mechanism in the presence of impaired nitric oxide availability.
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Affiliation(s)
- Chiara Giannarelli
- Department of Internal Medicine, University of Pisa, Via Roma 67, 56100 Pisa, Italy.
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Chen PJ, Padgett WT, Moore T, Winnik W, Lambert GR, Thai SF, Hester SD, Nesnow S. Three conazoles increase hepatic microsomal retinoic acid metabolism and decrease mouse hepatic retinoic acid levels in vivo. Toxicol Appl Pharmacol 2009; 234:143-55. [DOI: 10.1016/j.taap.2008.10.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2008] [Revised: 10/02/2008] [Accepted: 10/15/2008] [Indexed: 12/31/2022]
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Aoyama K, Yoshinari K, Kim HJ, Nagata K, Yamazoe Y. Simultaneous Expression of Plural Forms of Human Cytochrome P450 at Desired Ratios in HepG2 Cells: Adenovirus-mediated Tool for Cytochrome P450 Reconstitution. Drug Metab Pharmacokinet 2009; 24:209-17. [DOI: 10.2133/dmpk.24.209] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Shiizaki K, Ohsako S, Kawanishi M, Yagi T. Omeprazole Alleviates Benzo[a]pyrene Cytotoxicity by Inhibition of CYP1A1 Activity in Human and Mouse Hepatoma Cells. Basic Clin Pharmacol Toxicol 2008; 103:468-75. [DOI: 10.1111/j.1742-7843.2008.00309.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Masubuchi Y, Horie T. Toxicological Significance of Mechanism-Based Inactivation of Cytochrome P450 Enzymes by Drugs. Crit Rev Toxicol 2008; 37:389-412. [PMID: 17612953 DOI: 10.1080/10408440701215233] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cytochrome P450 (P450) enzymes oxidize xenobiotics into chemically reactive metabolites or intermediates as well as into stable metabolites. If the reactivity of the product is very high, it binds to a catalytic site or sites of the enzyme itself and inactivates it. This phenomenon is referred to as mechanism-based inactivation. Many clinically important drugs are mechanism-based inactivators that include macrolide antibiotics, calcium channel blockers, and selective serotonin uptake inhibitors, but are not always structurally and pharmacologically related. The inactivation of P450s during drug therapy results in serious drug interactions, since irreversibility of the binding allows enzyme inhibition to be prolonged after elimination of the causal drug. The inhibition of the metabolism of drugs with narrow therapeutic indexes, such as terfenadine and astemizole, leads to toxicities. On the other hand, the fate of P450s after the inactivation and the toxicological consequences remains to be elucidated, while it has been suggested that P450s modified and degraded are involved in some forms of tissue toxicity. Porphyrinogenic drugs, such as griseofulvin, cause mechanism-based heme inactivation, leading to formation of ferrochelatase-inhibitory N-alkylated protoporphyrins and resulting in porphyria. Involvement of P450-derived free heme in halothane-induced hepatotoxicity and catalytic iron in cisplatin-induced nephrotoxicity has also been suggested. Autoantibodies against P450s have been found in hepatitis following administration of tienilic acid and dihydralazine. Tienilic acid is activated by and covalently bound to CYP2C9, and the neoantigens thus formed activate immune systems, resulting in the formation of an autoantibodydirected against CYP2C9, named anti-liver/kidney microsomal autoantibody type 2, whereas the pathological role of the autoantibodies in drug-induced hepatitis remains largely unknown.
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Affiliation(s)
- Yasuhiro Masubuchi
- Laboratory of Clinical Pharmacy, Faculty of Pharmaceutical Sciences, Chiba Institute of Science, Chosi, Japan
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Sams C, Cocker J, Lennard MS. Biotransformation of chlorpyrifos and diazinon by human liver microsomes and recombinant human cytochrome P450s (CYP). Xenobiotica 2008; 34:861-73. [PMID: 15764407 DOI: 10.1080/00498250400017273] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The cytochrome P450 (CYP)-mediated biotransformation of the organophosphorothioate insecticides chlorpyrifos and diazinon was investigated. Rates of desulphuration to the active oxon metabolite (chlorpyrifos-oxon and diazinon-oxon) and dearylation to non-toxic hydrolysis products were determined in human liver microsome preparations from five individual donors and in recombinant CYP enzymes. Chlorpyrifos and diazinon underwent desulphuration in human liver microsome with mean Km = 30 and 45 microM and V(max) = 353 and 766 pmol min(-1) mg(-1), respectively. Dearylation of these compounds by human liver microsome proceeded with Km = 12 and 28 microM and V(max) = 653 and 1186 pmol min(-1) mg(-1), respectively. The apparent intrinsic clearance (V(max)/Km) of dearylation was 4.5- and 2.5-fold greater than desulphuration for chlorpyrifos and diazinon, respectively. Recombinant human CYP2B6 possessed the highest desulphuration activity for chlorpyrifos, whereas CYP2C19 had the highest dearylation activity. In contrast, both desulphuration and dearylation of diazinon were catalysed at similar rates, in the rank order CYP2C19 > CYP1A2 > CYP2B6 > CYP3A4. Both organophosphorothioates were more readily detoxified (dearylation) than bioactivated (desulphuration) in all human liver microsome preparations. However, the role of individual CYP enzymes in these two biotransformation pathways varied according to the structure of the organophosphorothioate, which was reflected in different activation/detoxification ratios for chlorpyrifos and diazinon. Variability in activity of individual CYP enzymes may influence interindividual sensitivity to the toxic effects of chlorpyrifos and diazinon.
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Affiliation(s)
- C Sams
- Health and Safety Laboratory, Broad Lane, Sheffield S3 7HQ, UK.
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Somers GI, Harris AJ, Bayliss MK, Houston JB. The metabolism of the 5HT3antagonists ondansetron, alosetron and GR87442 I: A comparison ofin vitroandin vivometabolism andin vitroenzyme kinetics in rat, dog and human hepatocytes, microsomes and recombinant human enzymes. Xenobiotica 2008; 37:832-54. [PMID: 17701832 DOI: 10.1080/00498250701485575] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
The metabolism of the structurally related 5HT3 antagonists ondansetron, alosetron and GR87442 in the rat, dog and human was determined in hepatocytes, liver microsomes and human recombinant microsomes. The profiles of phase I metabolites were similar in human hepatocytes and microsomes. The metabolites of all three compounds produced in rat, dog and human microsomes and hepatocytes were similar to those seen in vivo, with the major routes of metabolism being N-dealkylation and/or hydroxylation. There was more extensive metabolic processing in hepatocytes than in microsomes; however, sequential metabolism was less extensive in vitro compared with in vivo. The pharmacokinetics of the three 5HT3 antagonists investigated were dominated by CYP3A4 (and/or 2C9) compared with CYP1A2 in man, possibly determined by enzyme capacity rather than relative enzyme affinity. These data support the use of rat, dog and human hepatocytes for the prediction of in vivo metabolites of ondansetron, alosetron and GR87442.
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Pekthong D, Martin H, Abadie C, Bonet A, Heyd B, Mantion G, Richert L. Differential inhibition of rat and human hepatic cytochrome P450 by Andrographis paniculata extract and andrographolide. JOURNAL OF ETHNOPHARMACOLOGY 2008; 115:432-440. [PMID: 18053665 DOI: 10.1016/j.jep.2007.10.013] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2007] [Revised: 10/10/2007] [Accepted: 10/12/2007] [Indexed: 05/25/2023]
Abstract
The inhibitory effect of Andrographis paniculata extract (APE) and andrographolide (AND), the most medicinally active phytochemical in the extract, on hepatic cytochrome P450s (CYPs) activities was examined using rat and human liver microsomes. For this purpose, CYP1A2-dependent ethoxyresorufin-O-deethylation, CYP2B1-dependent benzyloxyresorufin-O-dealkylation, CYP2B6-dependent bupropion hydroxylation, CYP2C-dependent tolbutamide hydroxylation, CYP2E1-dependent p-nitrophenol hydroxylation and CYP3A-dependent testosterone 6 beta-hydroxylation activities, were determined in the presence and absence of APE or AND (0-200 microM). APE inhibited ethoxyresorufin-O-deethylation activity in rat and human liver microsomes, with apparent Ki values of 8.85 and 24.46 microM, respectively. In each case, the mode of inhibition was noncompetitive. APE also inhibited tolbutamide hydroxylation both in rat and human microsomes with apparent Ki values of 8.21 and 7.51 microM, respectively and the mode of inhibition was mixed type. In addition, APE showed a competitive inhibition only on CYP3A4 in human microsomes with Ki of 25.43 microM. AND was found to be a weak inhibitor of rat CYP2E1 with a Ki of 61.1 microM but did not affect human CYP2E1. In conclusion, it cannot be excluded from the present study that APE could cause drug-drug interactions in humans through CYP3A and 2C9 inhibition.
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Affiliation(s)
- D Pekthong
- Laboratoire de Toxicologie Cellulaire, EA 3921 Optimisation Métabolique et Cellulaire, UFR des Sciences Médicales et Pharmaceutiques, Besançon, France
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Purnapatre K, Khattar SK, Saini KS. Cytochrome P450s in the development of target-based anticancer drugs. Cancer Lett 2008; 259:1-15. [DOI: 10.1016/j.canlet.2007.10.024] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2007] [Revised: 10/16/2007] [Accepted: 10/17/2007] [Indexed: 11/16/2022]
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Kousba A, Soll R, Yee S, Martin M. Cyclic Conversion of the Novel Src Kinase Inhibitor [7-(2,6-Dichloro-phenyl)-5-methyl-benzo[1,2,4]triazin-3-yl]-[4-(2-pyrrolidin-1-yl-ethoxy)-phenyl]-amine (TG100435) and Its N-Oxide Metabolite by Flavin-Containing Monoxygenases and Cytochrome P450 Reductase. Drug Metab Dispos 2007; 35:2242-51. [PMID: 17881660 DOI: 10.1124/dmd.107.017384] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
[7-(2,6-Dichloro-phenyl)-5-methyl-benzo[1,2,4]triazin-3-yl]-[4-(2-pyrrolidin-1-yl-ethoxy)-phenyl]-amine (TG100435) is a novel multi-targeted Src family kinase inhibitor with demonstrated anticancer activity in preclinical species. Potent kinase inhibition is associated with TG100435 and its major N-oxide metabolite [7-(2,6-dichlorophenyl)-5-methyl-benzo[1,2,4]triazin-3-yl]-{4-[2-(1-oxy-pyrrolidin-1-yl)-ethoxy]-phenyl}-amine (TG100855). The objectives of the current study were to identify the hepatic enzyme(s) responsible for 1) the total metabolic flux of TG100435, 2) the formation of TG100855, and 3) the subsequent metabolism of TG100855. Flavin-containing monooxygenases (FMO) and cytochrome P450 monooxygenases (P450s) contribute to TG100435 total metabolic flux. TG100435 metabolic flux was completely inhibited by methimazole and ketoconazole, suggesting only FMO- and CYP3A4-mediated metabolism. TG100855 formation was markedly inhibited (~90%) by methimazole or heat inactivation (>99%). FMO3 was the primary enzyme responsible for TG100855 formation. In addition, an enzyme mediated retroreduction of TG100855 back to TG100435 was observed. The N-oxidation reaction was approximately 15 times faster than the retroreduction reaction. Interestingly, the retroreduction of TG100855 to TG100435 in recombinant P450 or liver microsomes lacked inhibition by the P450 inhibitors. TG100435 formation in the human liver microsomes or recombinant P450 increased as a function of cytochrome P450 reductase activity, suggesting potential involvement of cytochrome P450 reductase. The results of this in vitro study demonstrate the potential of TG100435 and TG100855 to be interconverted metabolically. FMO seem to be the major N-oxidizing enzymes, whereas cytochrome P450 reductase seems to be responsible for the retroreduction reaction.
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Affiliation(s)
- Ahmed Kousba
- Department of Pharmaceutical Property Assessment, TargeGen Inc, San Diego, CA 92121, USA.
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Somers GI, Bayliss MK, Houston JB. The metabolism of the 5HT3 antagonists, ondansetron, alosetron and GR87442 II: investigation into the in vitro methods used to predict the in vivo hepatic clearance of ondansetron, alosetron and GR87442 in the rat, dog and human. Xenobiotica 2007; 37:855-69. [PMID: 17701833 DOI: 10.1080/00498250701474058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
The in vitro clearances of the 5HT3 antagonists, ondansetron, alosetron and GR87442 were investigated. Intrinsic clearances using either metabolite formation or substrate depletion methods were equivalent (R2 = 0.95). Hepatocytes from preclinical species were superior to microsomes for the prediction of hepatic clearance (CL(H)), whereas the predictions from human microsomes and hepatocytes were similar. Using a non-restrictive model, seven of the nine CL(H) predictions using hepatocytes were within 2-fold of the in vivo CL(H) values. If the unbound fraction was included, the clearance of the compounds was generally under-predicted by both in vitro models. However, for the most metabolically stable compound, GR87442, the non-restrictive model over-predicted CLp. This and the possibility of extrahepatic metabolism indicate that the restrictive model is more appropriate for prediction of CL(H). The rank order of metabolic stability correlated with that in vivo. All three compounds were more metabolically stable in human than in the preclinical animal species examined.
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