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Yamazoe Y, Yoshinari K. Construction of a fused grid-based CYP2C18-Template system and its application to drug metabolism. Drug Metab Pharmacokinet 2024; 54:100534. [PMID: 38070310 DOI: 10.1016/j.dmpk.2023.100534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 10/08/2023] [Accepted: 10/16/2023] [Indexed: 02/06/2024]
Abstract
Detailed estimation of cytochrome P450 (CYP)-mediated metabolisms of medicine and other chemicals is necessary for the efficacy and safety assessments. Data on the metabolisms mediated by minor CYP enzymes like CYP2C18 are often not available in metabolisms and safety assessments of chemicals except for medical drugs developed recently. A ligand-accessible space in the active site of human CYP2C18 was thus reconstituted as a fused grid-based Template with the use of structural data of its ligands. An evaluation system of CYP2C18-mediated metabolism was then developed on Template with the introduction of the idea of movement and fastening of ligands after Trigger-residue contact. Reciprocal comparison of the data of simulations on Template with experimental results suggested a unified way of the interaction of CYP2C18, in similar to the CYP2C8 interaction (Drug Metab Pharmacokinet 2023, in press). These experiments also displayed the roles of initial Trigger-residue-localizations on their distinct catalyses among human CYP2C enzymes. Simulation experiments for over 130 reactions of CYP2C18 ligands supported the system established.
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Affiliation(s)
- Yasushi Yamazoe
- Division of Drug Metabolism and Molecular Toxicology, Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aramaki-Aoba, Aoba-ku, Sendai, 980-8578, Japan; Division of Risk Assessment, National Institute of Health Sciences, Tonomachi 3-25-26, Kawasaki-ku, Kawasaki, 210-9501, Japan.
| | - Kouichi Yoshinari
- Laboratory of Molecular Toxicology, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka, 422-8526, Japan
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2
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Li G, Cheng Y, Han C, Song C, Huang N, Du Y. Pyrazole-containing pharmaceuticals: target, pharmacological activity, and their SAR studies. RSC Med Chem 2022; 13:1300-1321. [PMID: 36439976 PMCID: PMC9667768 DOI: 10.1039/d2md00206j] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Accepted: 08/25/2022] [Indexed: 11/21/2022] Open
Abstract
Pyrazole is a five-membered heterocycle bearing two adjacent nitrogen atoms. Both pharmaceutical agents and natural products with pyrazole as a nucleus have exhibited a broad spectrum of biological activities. In the last few decades, more than 40 pyrazole-containing drugs have been approved by the FDA for the treatment of a broad range of clinical conditions including celecoxib (anti-inflammatory), CDPPB (antipsychotic), difenamizole (analgesic), etc. Owing to the unique physicochemical properties of the pyrazole core, pyrazole-containing drugs may exert better pharmacokinetics and pharmacological effects compared with drugs containing similar heterocyclic rings. The purpose of this paper is to provide an overview of all the existing drugs bearing a pyrazole nucleus that have been approved or in clinical trials, involving their pharmacological activities and SAR studies.
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Affiliation(s)
- Guangchen Li
- School of Pharmaceutical Science and Technology, Tianjin University Tianjin 300072 China
| | - Yifu Cheng
- School of Pharmaceutical Science and Technology, Tianjin University Tianjin 300072 China
| | - Chi Han
- School of Pharmaceutical Science and Technology, Tianjin University Tianjin 300072 China
| | - Chun Song
- State Key Laboratory of Microbial Technology, Shandong University Qing Dao City Shandong Province 266237 China
| | - Niu Huang
- National Institution of Biological Sciences Beijing, No. 7 Science Park Road, Zhongguancun Life Science Park Beijing 102206 China
- Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University Beijing 102206 China
| | - Yunfei Du
- School of Pharmaceutical Science and Technology, Tianjin University Tianjin 300072 China
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3
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Chen H, Wang B, Li P, Yan H, Li G, Huang H, Lu Y. The optimization and characterization of functionalized sulfonamides derived from sulfaphenazole against Mycobacterium tuberculosis with reduced CYP 2C9 inhibition. Bioorg Med Chem Lett 2021; 40:127924. [PMID: 33705901 DOI: 10.1016/j.bmcl.2021.127924] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 02/08/2021] [Accepted: 02/25/2021] [Indexed: 01/02/2023]
Abstract
In this study, a series of sulfonamide compounds was designed and synthesized through the systematic optimization of the antibacterial agent sulfaphenazole for the treatment of Mycobacterium tuberculosis (M. tuberculosis). Preliminary results indicate that the 4-aminobenzenesulfonamide moiety plays a key role in maintaining antimycobacterial activity. Compounds 10c, 10d, 10f and 10i through the optimization on phenyl ring at the R2 site on the pyrazole displayed promising antimycobacterial activity paired with low cytotoxicity. In particular, compound 10d displayed good activity (MIC = 5.69 μg/mL) with low inhibition of CYP 2C9 (IC50 > 10 μM), consequently low potential risk of drug-drug interaction. These promising results provide new insight into the combination regimen using sulfonamide as one component for the treatment of M. tuberculosis.
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Affiliation(s)
- Hui Chen
- Beijing Key Laboratory of Environmental and Viral Oncology, College of Life Science and Bio-engineering, Beijing University of Technology, Beijing 100124, PR China
| | - Bin Wang
- Beijing Key Laboratory of Drug Resistance Tuberculosis Research, Department of Pharmacology, Beijing Tuberculosis and Thoracic Tumor Research Institute, Beijing Chest Hospital, Capital Medical University, Beijing 101149, PR China
| | - Peng Li
- Beijing Key Laboratory of Active Substance Discovery and Druggability Evaluation & Chinese Academy of Medical Sciences Key Laboratory of Anti-DR TB Innovative Drug Research, Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100050, PR China
| | - Hong Yan
- Beijing Key Laboratory of Environmental and Viral Oncology, College of Life Science and Bio-engineering, Beijing University of Technology, Beijing 100124, PR China
| | - Gang Li
- Beijing Key Laboratory of Active Substance Discovery and Druggability Evaluation & Chinese Academy of Medical Sciences Key Laboratory of Anti-DR TB Innovative Drug Research, Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100050, PR China.
| | - Haihong Huang
- Beijing Key Laboratory of Active Substance Discovery and Druggability Evaluation & Chinese Academy of Medical Sciences Key Laboratory of Anti-DR TB Innovative Drug Research, Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100050, PR China.
| | - Yu Lu
- Beijing Key Laboratory of Drug Resistance Tuberculosis Research, Department of Pharmacology, Beijing Tuberculosis and Thoracic Tumor Research Institute, Beijing Chest Hospital, Capital Medical University, Beijing 101149, PR China.
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Tan BH, Ahemad N, Pan Y, Palanisamy UD, Othman I, Yiap BC, Ong CE. Cytochrome P450 2C9-natural antiarthritic interactions: Evaluation of inhibition magnitude and prediction from in vitro data. Biopharm Drug Dispos 2018; 39:205-217. [PMID: 29488228 DOI: 10.1002/bdd.2127] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 02/10/2018] [Accepted: 02/18/2018] [Indexed: 11/08/2022]
Abstract
Many dietary supplements are promoted to patients with osteoarthritis (OA) including the three naturally derived compounds, glucosamine, chondroitin and diacerein. Despite their wide spread use, research on interaction of these antiarthritic compounds with human hepatic cytochrome P450 (CYP) enzymes is limited. This study aimed to examine the modulatory effects of these compounds on CYP2C9, a major CYP isoform, using in vitro biochemical assay and in silico models. Utilizing valsartan hydroxylase assay as probe, all forms of glucosamine and chondroitin exhibited IC50 values beyond 1000 μM, indicating very weak potential in inhibiting CYP2C9. In silico docking postulated no interaction with CYP2C9 for chondroitin and weak bonding for glucosamine. On the other hand, diacerein exhibited mixed-type inhibition with IC50 value of 32.23 μM and Ki value of 30.80 μM, indicating moderately weak inhibition. Diacerein's main metabolite, rhein, demonstrated the same mode of inhibition as diacerein but stronger potency, with IC50 of 6.08 μM and Ki of 1.16 μM. The docking of both compounds acquired lower CDOCKER interaction energy values, with interactions dominated by hydrogen and hydrophobic bondings. The ranking with respect to inhibition potency for the investigated compounds was generally the same in both in vitro enzyme assay and in silico modeling with order of potency being diacerein/rhein > various glucosamine/chondroitin forms. In vitro-in vivo extrapolation of inhibition kinetics (using 1 + [I]/Ki ratio) demonstrated negligible potential of diacerein to cause interaction in vivo, whereas rhein was predicted to cause in vivo interaction, suggesting potential interaction risk with the CYP2C9 drug substrates.
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Affiliation(s)
- Boon Hooi Tan
- Division of Applied Biomedical Sciences and Biotechnology, International Medical University, Bukit Jalil, Kuala Lumpur, Malaysia
| | - Nafees Ahemad
- School of Pharmacy, Monash University Malaysia, Bandar Sunway, Selangor, Malaysia
| | - Yan Pan
- Department of Biomedical Science, University of Nottingham Malaysia Campus, Semenyih, Selangor, Malaysia
| | - Uma Devi Palanisamy
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway, Selangor, Malaysia
| | - Iekhsan Othman
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway, Selangor, Malaysia
| | - Beow Chin Yiap
- School of Pharmacy, International Medical University, Bukit Jalil, Kuala Lumpur, Malaysia
| | - Chin Eng Ong
- School of Pharmacy, International Medical University, Bukit Jalil, Kuala Lumpur, Malaysia
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5
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Ziniel PD, Karumudi B, Barnard AH, Fisher EMS, Thatcher GRJ, Podust LM, Williams DL. The Schistosoma mansoni Cytochrome P450 (CYP3050A1) Is Essential for Worm Survival and Egg Development. PLoS Negl Trop Dis 2015; 9:e0004279. [PMID: 26713732 PMCID: PMC4694641 DOI: 10.1371/journal.pntd.0004279] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Accepted: 11/13/2015] [Indexed: 12/29/2022] Open
Abstract
Schistosomiasis affects millions of people in developing countries and is responsible for more than 200,000 deaths annually. Because of toxicity and limited spectrum of activity of alternatives, there is effectively only one drug, praziquantel, available for its treatment. Recent data suggest that drug resistance could soon be a problem. There is therefore the need to identify new drug targets and develop drugs for the treatment of schistosomiasis. Analysis of the Schistosoma mansoni genome sequence for proteins involved in detoxification processes found that it encodes a single cytochrome P450 (CYP450) gene. Here we report that the 1452 bp open reading frame has a characteristic heme-binding region in its catalytic domain with a conserved heme ligating cysteine, a hydrophobic leader sequence present as the membrane interacting region, and overall structural conservation. The highest sequence identity to human CYP450s is 22%. Double stranded RNA (dsRNA) silencing of S. mansoni (Sm)CYP450 in schistosomula results in worm death. Treating larval or adult worms with antifungal azole CYP450 inhibitors results in worm death at low micromolar concentrations. In addition, combinations of SmCYP450-specific dsRNA and miconazole show additive schistosomicidal effects supporting the hypothesis that SmCYP450 is the target of miconazole. Treatment of developing S. mansoni eggs with miconazole results in a dose dependent arrest in embryonic development. Our results indicate that SmCYP450 is essential for worm survival and egg development and validates it as a novel drug target. Preliminary structure-activity relationship suggests that the 1-(2,4-dichlorophenyl)-2-(1H-imidazol-1-yl)ethan-1-ol moiety of miconazole is necessary for activity and that miconazole activity and selectivity could be improved by rational drug design. Over 600 million people in endemic countries are at risk of contracting schistosomiasis, which results in over 200,000 deaths each year and significant illness to most people that are infected. There are concerns that the drug widely used for the treatment of schistosomiasis, praziquantel, may be losing efficacy due to evolution of drug resistant worms. Since the disease mainly affects the poor in developing countries, pharmaceutical companies have little interest in developing new drugs and none are currently being tested. In this paper we focus on a novel parasite protein, cytochrome P450, which we propose to be a new drug target. Worms are unusual in having only one cytochrome P450 gene; humans have 57 cytochrome P450 genes. By using reverse genetic and chemical approaches we found that the schistosome cytochrome P450 is essential for worm survival and egg development and, therefore, is an essential and druggable target. Drugs that target fungal cytochrome P450s and are already in use for treating several human diseases were identified as potential hits for further development for schistosomiasis treatment.
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Affiliation(s)
- Peter D. Ziniel
- Department of Immunology & Microbiology, Rush University Medical Center, Chicago, Illinois, United States of America
| | - Bhargava Karumudi
- Department of Medicinal Chemistry and Pharmacognosy, University of Illinois College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Andrew H. Barnard
- Department of Immunology & Microbiology, Rush University Medical Center, Chicago, Illinois, United States of America
| | - Ethan M. S. Fisher
- Department of Immunology & Microbiology, Rush University Medical Center, Chicago, Illinois, United States of America
| | - Gregory R. J. Thatcher
- Department of Medicinal Chemistry and Pharmacognosy, University of Illinois College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Larissa M. Podust
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California, United States of America
| | - David L. Williams
- Department of Immunology & Microbiology, Rush University Medical Center, Chicago, Illinois, United States of America
- * E-mail:
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6
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Schranck J, Tlili A, Alsabeh PG, Neumann H, Stradiotto M, Beller M. Palladium-Catalysed Carbonylative α-Arylation of Acetone and Acetophenones to 1,3-Diketones. Chemistry 2013; 19:12624-8. [DOI: 10.1002/chem.201302590] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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7
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Synthesis and evaluation of antibacterial and antifungal activities of new (Z)-3-bromo-4-(1,3-diaryl-1H-pyrazol-4-yl)but-3-en-2-ones and 4-(3-methyl-1-phenyl-1H-pyrazol-5-yl)-1,3-diaryl-1H-pyrazoles. Med Chem Res 2013. [DOI: 10.1007/s00044-013-0480-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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8
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9
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Schranck J, Wu XF, Neumann H, Beller M. Palladium-catalyzed carbonylative Heck reaction of aryl bromides with vinyl ethers to 3-alkoxy alkenones and pyrazoles. Chemistry 2012; 18:4827-31. [PMID: 22422673 DOI: 10.1002/chem.201103643] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2011] [Revised: 01/18/2012] [Indexed: 11/07/2022]
Abstract
Three COming together: The first carbonylative Heck coupling reaction of aryl bromides and vinyl ethers leading to 1-aryl-3-alkoxy-2-propen-1-ones has been established (see scheme). Based on this coupling methodology, a novel one-pot synthesis of aryl-substituted pyrazoles was also realized.
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Affiliation(s)
- Johannes Schranck
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein-Straße 29a, 18059 Rostock, Germany
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10
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Khera RA, Ali A, Rafique H, Hussain M, Tatar J, Saeed A, Villinger A, Langer P. Suzuki–Miyaura reactions of N-protected tribromopyrazoles. Efficient and site-selective synthesis of 3,4,5-triaryl-pyrazoles, 3,5-diaryl-4-bromopyrazoles and 5-aryl-3,4-dibromopyrazoles. Tetrahedron 2011. [DOI: 10.1016/j.tet.2011.05.036] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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11
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Arbačiauskienė E, Vilkauskaitė G, Eller GA, Holzer W, Šačkus A. Pd-catalyzed cross-coupling reactions of halogenated 1-phenylpyrazol-3-ols and related triflates. Tetrahedron 2009. [DOI: 10.1016/j.tet.2009.07.017] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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12
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In vitro cytochrome p450 formation of a mono-hydroxylated metabolite of zearalenone exhibiting estrogenic activities: possible occurrence of this metabolite in vivo. Int J Mol Sci 2009; 10:1824-37. [PMID: 19468341 PMCID: PMC2680649 DOI: 10.3390/ijms10041824] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2009] [Accepted: 04/16/2009] [Indexed: 11/19/2022] Open
Abstract
The mycoestrogen zearalenone (ZEN), as well as its reduced metabolites, which belong to the endocrine disruptor bio-molecule family, are substrates for various enzymes involved in steroid metabolism. In addition to its reduction by the steroid dehydrogenase pathway, ZEN also interacts with hepatic detoxification enzymes, which convert it into hydroxylated metabolites (OH-ZEN). Due to their structures to that of estradiol, ZEN and its derived metabolites bind to the estrogen receptors and are involved in endocrinal perturbations and are possibly associated with estrogen-dependent cancers. The primary aim of this present study was to identify the enzymatic cytochrome P450 isoforms responsible for the formation of the most abundant OH-ZEN. We thus studied its in vitro formation using hepatic microsomes in a range of animal model systems including man. OH-ZEN was also recovered in liver and urine of rats treated orally with ZEN. Finally we compared the activity of ZEN and its active metabolites (α-ZAL and OH-ZEN) on estrogen receptors using HeLa ER-α and ER-β reporter cell lines as reporters. OH-ZEN estrogenic activities were revealed to be limited and not as significant as those of ZEN or α-ZAL.
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13
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Foti RS, Dickmann LJ, Davis JA, Greene RJ, Hill JJ, Howard ML, Pearson JT, Rock DA, Tay JC, Wahlstrom JL, Slatter JG. Metabolism and related human risk factors for hepatic damage by usnic acid containing nutritional supplements. Xenobiotica 2008; 38:264-80. [PMID: 18274956 DOI: 10.1080/00498250701802514] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Usnic acid is a component of nutritional supplements promoted for weight loss that have been associated with liver-related adverse events including mild hepatic toxicity, chemical hepatitis, and liver failure requiring transplant. To determine if metabolism factors might have had a role in defining individual susceptibility to hepatotoxicity, in vitro metabolism studies were undertaken using human plasma, hepatocytes, and liver subcellular fractions. Usnic acid was metabolized to form three monohydroxylated metabolites and two regio-isomeric glucuronide conjugates of the parent drug. Oxidative metabolism was mainly by cytochrome P450 (CYP) 1A2 and glucuronidation was carried out by uridine diphosphate-glucuronosyltransferase (UGT) 1A1 and UGT1A3. In human hepatocytes, usnic acid at 20 microM was not an inducer of CYP1A2, CYP2B6, or CYP3A4 relative to positive controls omeprazole, phenobarbital, and rifampicin, respectively. Usnic acid was a relatively weak inhibitor of CYP2D6 and a potent inhibitor of CYP2C19 (the concentration eliciting 50% inhibition (IC(50)) = 9 nM) and CYP2C9 (IC(50) = 94 nM), with less potent inhibition of CYP2C8 (IC(50) = 1.9 microM) and CYP2C18 (IC(50) = 6.3 microM). Pre-incubation of microsomes with usnic acid did not afford any evidence of time-dependent inhibition of CYP2C19, although evidence of slight time-dependent inhibition of CYP2C9 (K(I) = 2.79 microM and K(inact) = 0.022 min(-1)) was obtained. In vitro data were used with SimCYP(R)to model potential drug interactions. Based on usnic acid doses in case reports of 450 mg to >1 g day(-1), these in vitro data indicate that usnic acid has significant potential to interact with other medications. Individual characteristics such as CYP1A induction status, co-administration of CYP1A2 inhibitors, UGT1A1 polymorphisms, and related hyperbilirubinaemias, or co-administration of low therapeutic index CYP2C substrates could work alone or in consort with other idiosyncrasy risk factors to increase the risk of adverse events and/or hepatotoxicity. Thus, usnic acid in nutritional supplements might be involved as both victim and/or perpetrator in clinically significant drug-drug interactions.
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Affiliation(s)
- R S Foti
- Biochemistry and Biophysics Group, Pharmacokinetics and Drug Metabolism, Amgen, Inc., Seattle, WA, USA
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Larsen BT, Gutterman DD, Sato A, Toyama K, Campbell WB, Zeldin DC, Manthati VL, Falck JR, Miura H. Hydrogen peroxide inhibits cytochrome p450 epoxygenases: interaction between two endothelium-derived hyperpolarizing factors. Circ Res 2007; 102:59-67. [PMID: 17975109 DOI: 10.1161/circresaha.107.159129] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The cytochrome P450 epoxygenase (CYP)-derived metabolites of arachidonic acid the epoxyeicosatrienoic acids (EETs) and hydrogen peroxide (H2O2) both function as endothelium-derived hyperpolarizing factors (EDHFs) in the human coronary microcirculation. However, the relative importance of and potential interactions between these 2 vasodilators remain unexplored. We identified a novel inhibitory interaction between CYPs and H2O2 in human coronary arterioles, where EDHF-mediated vasodilatory mechanisms are prominent. Bradykinin induced vascular superoxide and H2O2 production in an endothelium-dependent manner and elicited a concentration-dependent dilation that was reduced by catalase but not by 14,15-epoxyeicosa-5(Z)-enoic acid (EEZE), 6-(2-propargyloxyphenyl)hexanoic acid, sulfaphenazole, or iberiotoxin. However, in the presence of catalase, an inhibitory effect of these compounds was unmasked. In a tandem-bioassay preparation, application of bradykinin to endothelium-intact donor vessels elicited dilation of downstream endothelium-denuded detectors that was partially inhibited by donor-applied catalase but not by detector-applied EEZE; however, EEZE significantly inhibited dilation in the presence of catalase. EET production by human recombinant CYP 2C9 and 2J2, 2 major epoxygenase isozymes expressed in human coronary arterioles, was directly inhibited in a concentration-dependent fashion by H2O2 in vitro, as observed by high-performance liquid chromatography (HPLC); however, EETs were not directly sensitive to oxidative modification. H2O2 inhibited dilation to arachidonic acid but not to 11,12-EET. These findings suggest that an inhibitory interaction exists between 2 EDHFs in the human coronary microcirculation. CYP epoxygenases are directly inhibited by H2O2, and this interaction may modulate vascular EET bioavailability.
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Affiliation(s)
- Brandon T Larsen
- Department of Pharmacology & Toxicology, Medical College of Wisconsin, 8701 Watertown Plank Rd, Milwaukee, WI 53226, USA
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15
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Polgár T, Menyhárd DK, Keserű GM. Effective virtual screening protocol for CYP2C9 ligands using a screening site constructed from flurbiprofen and S-warfarin pockets. J Comput Aided Mol Des 2007; 21:539-48. [DOI: 10.1007/s10822-007-9137-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2007] [Accepted: 09/26/2007] [Indexed: 11/28/2022]
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16
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Usmani KA, Karoly ED, Hodgson E, Rose RL. In vitro sulfoxidation of thioether compounds by human cytochrome P450 and flavin-containing monooxygenase isoforms with particular reference to the CYP2C subfamily. Drug Metab Dispos 2004; 32:333-9. [PMID: 14977868 DOI: 10.1124/dmd.32.3.333] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Cytochrome P450 (P450) and flavin-containing monooxygenase (FMO) enzymes are major catalysts involved in the metabolism of xenobiotics. The sulfoxidation of the thioether pesticides, phorate, disulfoton, sulprofos, and methiocarb, was investigated. Using pooled human liver microsomes (HLMs), thioether compounds displayed similar affinities; however, phorate and disulfoton displayed higher intrinsic clearance rates than either sulprofos or methiocarb. The sulfoxidation of thioethers by HLMs was found to be predominantly P450-driven (85-90%) compared with FMO (10-15%). Among 16 cDNA-expressed human P450 isoforms and 3 human FMO isoforms examined, the following isoforms and their polymorphisms had the highest rates for sulfoxidation, as follows: phorate, CYP1A2, 3A4, 2B6, 2C9*1, 2C18, 2C19, 2D6*1, and FMO1; disulfoton, CYP1A2, 3A4, 2B6, 2C9*1, 2C9*2, 2C18, 2C19, 2D6*1, and FMO1; sulprofos, CYP1A1, 1A2, 3A4, 2C9*1, 2C9*2, 2C9*3, 2C18, 2C19, 2D6*1, and FMO1; methiocarb, CYP1A1, 1A2, 3A4, 2B6, 2C9*1, 2C19, 2D6*1, and FMO1. Among these isoforms, members of the CYP2C subfamily often had the highest affinities and clearance rates. Moreover, sulfaphenazole, a CYP2C9 competitive inhibitor, inhibited disulfoton sulfoxidation by CYP2C9 (IC50 0.84 microM) as well as in HLMs. Ticlopidine, a CYP2C19 mechanism-based inhibitor, inhibited disulfoton sulfoxidation by CYP2C19 (IC50 after coincubation, 43.5 microM; IC50 after preincubation, 4.3 microM) and also in HLMs. Our results indicate that current models of the substrate binding site of the CYP2C subfamily would not effectively predict thioether pesticide metabolism. Thus, the substrate specificity of CYP2Cs is more extensive than is currently believed, and some reevaluation of structure-activity relationships may be required.
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Affiliation(s)
- Khawja A Usmani
- Department of Environmental and Molecular Toxicology, North Carolina State University, Raleigh, North Carolina 27695, USA
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17
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Meunier B, de Visser SP, Shaik S. Mechanism of Oxidation Reactions Catalyzed by Cytochrome P450 Enzymes. Chem Rev 2004; 104:3947-80. [PMID: 15352783 DOI: 10.1021/cr020443g] [Citation(s) in RCA: 1717] [Impact Index Per Article: 85.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Bernard Meunier
- Laboratoire de Chimie de Coordination du CNRS, 205 route de Narbonne, 31077 Toulouse Cedex 4, France.
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18
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Affiliation(s)
- Corwin Hansch
- Department of Chemistry, Pomona College, Claremont, California 91711, USA.
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19
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Pfister SL, Spitzbarth N, Zeldin DC, Lafite P, Mansuy D, Campbell WB. Rabbit aorta converts 15-HPETE to trihydroxyeicosatrienoic acids: potential role of cytochrome P450. Arch Biochem Biophys 2004; 420:142-52. [PMID: 14622984 DOI: 10.1016/j.abb.2003.09.026] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Previous work showed that rabbit aorta metabolizes arachidonic acid via 15-lipoxygenase to 15-hydroperoxyeicosatetraenoic acid (15-HPETE), which undergoes an enzymatic rearrangement to 11-hydroxy-14,15-epoxyeicosatrienoic acid (11-H-14,15-EETA) and 15-hydroxy-11,12-epoxyeicosatrienoic acid (15-H-11,12-EETA). Hydrolysis of the epoxy group results in the formation of 11,14,15- and 11,12,15-trihydroxyeicosatrienoic acids (THETAs). Endothelial cells have several heme-containing enzymes including cytochromes P450 (CYP), nitric oxide synthase (eNOS), and prostacyclin (PGI(2)) synthase that catalyze the rearrangement of 15-HPETE to HEETAs. Incubation of arachidonic acid and 15-lipoxygenase, or 15-HPETE with rabbit aortic microsomes or rat liver microsomes, a rich source of CYP, resulted in the formation of a product that comigrated with THETAs and HEETAs on HPLC. Immunoblot analysis showed the presence of CYP2C8 and CYP2J2 in aortic tissue and when CYP2J2 or CYP2C8 was incubated with arachidonic acid and 15-lipoxygenase, the major products were 11,12,15- and 11,14,15-THETAs. Incubation of purified hematin, CYP2C11, eNOS or PGI(2) synthase enzymes with arachidonic acid and 15-lipoxygenase produced a different pattern of metabolites from rabbit aortic microsomes. Clotrimazole, a non-specific CYP inhibitor, and ebastine and terfenadone, specific CYP2J2 inhibitors, blocked the ability of aortic microsomes to produce THETAs while specific inhibitors of PGI(2) synthase, eNOS or CYP2C8/2C9 had no effect on THETA production. We suggest that a CYP, possibly CYP2J2, may function as the hydroperoxide isomerase converting 15-HPETE to HEETAs in rabbit vascular tissue. Further hydrolysis of the epoxy group of the HEETAs results in the formation of 11,12,15- and 11,14,15-THETAs. The HEETAs and THETAs are both vasodilators and may function as important regulators of vascular tone.
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Affiliation(s)
- Sandra L Pfister
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
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Melet A, Assrir N, Jean P, Pilar Lopez-Garcia M, Marques-Soares C, Jaouen M, Dansette PM, Sari MA, Mansuy D. Substrate selectivity of human cytochrome P450 2C9: importance of residues 476, 365, and 114 in recognition of diclofenac and sulfaphenazole and in mechanism-based inactivation by tienilic acid. Arch Biochem Biophys 2003; 409:80-91. [PMID: 12464247 DOI: 10.1016/s0003-9861(02)00548-9] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A series of six site-directed mutants of CYP 2C9 were constructed with the aim to better define the amino acid residues that play a critical role in substrate selectivity of CYP 2C9, particularly in three distinctive properties of this enzyme: (i) its selective mechanism-based inactivation by tienilic acid (TA), (ii) its high affinity and hydroxylation regioselectivity toward diclofenac, and (iii) its high affinity for the competitive inhibitor sulfaphenazole (SPA). The S365A mutant exhibited kinetic characteristics for the 5-hydroxylation of TA very similar to those of CYP 2C9; however, this mutant did not undergo any detectable mechanism-based inactivation by TA, which indicates that the OH group of Ser 365 could be the nucleophile forming a covalent bond with an electrophilic metabolite of TA in TA-dependent inactivation of CYP 2C9. The F114I mutant was inactive toward the hydroxylation of diclofenac; moreover, detailed analyses of its interaction with a series of SPA derivatives by difference visible spectroscopy showed that the high affinity of SPA to CYP 2C9 (K(s)=0.4 microM) was completely lost when the phenyl substituent of Phe 114 was replaced with the alkyl group of Ile (K(s)=190+/-20 microM), or when the phenyl substituent of SPA was replaced with a cyclohexyl group (K(s)=120+/-30 microM). However, this cyclohexyl derivative of SPA interacted well with the F114I mutant (K(s)=1.6+/-0.5 microM). At the opposite end, the F94L and F110I mutants showed properties very similar to those of CYP 2C9 toward TA and diclofenac. Finally, the F476I mutant exhibited at least three main differences compared to CYP 2C9: (i) big changes in the k(cat) and K(m) values for TA and diclofenac hydroxylation, (ii) a 37-fold increase of the K(i) value found for the inhibition of CYP 2C9 by SPA, and (iii) a great change in the regioselectivity of diclofenac hydroxylation, the 5-hydroxylation of this substrate by CYP 2C9 F476I exhibiting a k(cat) of 28min(-1). These data indicate that Phe 114 plays an important role in recognition of aromatic substrates of CYP 2C9, presumably via Pi-stacking interactions. They also provide the first experimental evidence showing that Phe 476 plays a crucial role in substrate recognition and hydroxylation by CYP 2C9.
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Affiliation(s)
- Armelle Melet
- Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques, UMR 8601 CNRS, Université Paris V, 45 Rue des Saints-Pères, 75270 06 Paris Cedex, France
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