1
|
He L, Chen C, Duan S, Li Y, Li C, Yao X, Gonzalez FJ, Qin Z, Yao Z. Inhibition of estrogen sulfation by Xian-Ling-Gu-Bao capsule. J Steroid Biochem Mol Biol 2023; 225:106182. [PMID: 36152789 DOI: 10.1016/j.jsbmb.2022.106182] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 09/07/2022] [Accepted: 09/18/2022] [Indexed: 02/01/2023]
Abstract
Xian-Ling-Gu-Bao capsule (XLGB) is a widely prescribed traditional Chinese medicine used for the treatment of osteoporosis. However, it significantly elevates levels of serum estrogens. Here we aimed to assess the dominant contributors of sulfotransferase (SULT) enzymes to the sulfation of estrogens and identify the effective inhibitors of this pathway in XLGB. First, estrone, 17β-estradiol, and estriol underwent sulfation in human liver S9 extracts. Phenotyping reactions and enzyme kinetics assays revealed that SULT1A1, 1A2, 1A3, 1C4, 1E1, and 2A1 all participated in estrogen sulfation, with SULT1E1 and 1A1 as the most important contributors. The incubation system for these two active enzymes were optimized with Tris-HCl buffer, DL-Dithiothreitol (DTT), MgCl2, adenosine 3'-phosphate 5'-phosphosulfate (PAPS), protein concentration, and incubation time. Then, 29 compounds in XLGB were selected to investigate their inhibitory effects and mechanisms against SULT1E1 and 1A1 through kinetic modelling. Moreover, in silico molecular docking was used to validate the obtained results. And finally, the prenylated flavonoids (isobavachin, neobavaisoflavone, etc.) from Psoralea corylifolia L., prenylated flavanols (icariside II) from Epimedium brevicornu Maxim., tanshinones (dihydrotanshinone, tanshinone II-A,) from Salvia miltiorrhiza Bge., and others (corylifol A, corylin) were identified as the most potent inhibitors of estrogen sulfation. Taken together, these findings provide insights into the understanding regioselectivity of estrogen sulfation and identify the effective components of XLGB responsible for the promotion of estrogen levels.
Collapse
Affiliation(s)
- Liangliang He
- College of Pharmacy, Jinan University, Guangzhou 510632, China
| | - Chanjuan Chen
- College of Pharmacy, Jinan University, Guangzhou 510632, China
| | - Shuyi Duan
- Department of Pharmacology, the First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China
| | - Yang Li
- College of Pharmacy, Jinan University, Guangzhou 510632, China
| | - Chuan Li
- State key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Xinsheng Yao
- College of Pharmacy, Jinan University, Guangzhou 510632, China; International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development Ministry of PR China, Jinan University, Guangzhou 510632, China
| | - Frank J Gonzalez
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Zifei Qin
- College of Pharmacy, Jinan University, Guangzhou 510632, China; Department of Pharmacology, the First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China.
| | - Zhihong Yao
- College of Pharmacy, Jinan University, Guangzhou 510632, China; State key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China; International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development Ministry of PR China, Jinan University, Guangzhou 510632, China.
| |
Collapse
|
2
|
Cheng S, Flora DR, Rettie AE, Brundage RC, Tracy TS. Pharmacokinetic Modeling of Warfarin ІI - Model-based Analysis of Warfarin Metabolites following Warfarin Administered either Alone or Together with Fluconazole or Rifampin. Drug Metab Dispos 2022; 50:DMD-AR-2022-000877. [PMID: 35798368 PMCID: PMC9488977 DOI: 10.1124/dmd.122.000877] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 05/16/2022] [Accepted: 05/31/2022] [Indexed: 11/22/2022] Open
Abstract
The objective of this study is to conduct a population pharmacokinetic (PK) model-based analysis on 10 warfarin metabolites (4'-, 6-, 7-, 8- and 10-hydroxylated (OH)-S- and R- warfarin), when warfarin is administered alone or together with either fluconazole or rifampin. One or two compartment PK models expanded from target mediated drug disposition (TMDD) models developed previously for warfarin enantiomers were able to sufficiently characterize the PK profiles of 10 warfarin metabolites in plasma and urine under different conditions. Model-based analysis shows CYP2C9 mediated metabolic elimination pathways are more inhibitable by fluconazole (% formation CL (CLf) of 6- and 7-OH-S-warfarin decrease: 73.2% and 74.8%) but less inducible by rifampin (% CLf of 6- and 7-OH-S-warfarin increase: 85% and 75%), compared with non-CYP2C9 mediated elimination pathways (% CLf of 10-OH-S-warfarin and CLR of S-warfarin decrease in the presence of fluconazole: 65.0% and 15.3%; % CLf of 4'- 8- and 10-OH-S-warfarin increase in the presence of rifampin: 260%, 127% and 355%), which potentially explains the CYP2C9 genotype-dependent DDIs exhibited by S-warfarin, when warfarin is administrated together with fluconazole or rifampin. Additionally, for subjects with CYP2C9 *2 and *3 variants, a model-based analysis of warfarin metabolite profiles in subjects with various CYP2C9 genotypes demonstrates CYP2C9 mediated elimination is less important and non-CYP2C9 mediated elimination is more important, compared with subjects without these variants. To our knowledge, this is so far one of the most comprehensive population-based PK analyses of warfarin metabolites in subjects with various CYP2C9 genotypes under different co-medications. Significance Statement The studies we wish to publish are potentially impactful. The need for a TMDD pharmacokinetic model and the demonstration of genotyped-dependent drug interactions may explain the extensive variability in dose-response relationships that are seen in the clinical dose adjustments of warfarin.
Collapse
Affiliation(s)
| | - Darcy R Flora
- Present Affiliation: GRYT Health Inc., United States
| | - Allan E Rettie
- Dept. of Medicinal Chemistry, University of Washington, United States
| | - Richard C Brundage
- Experimental and Clinical Pharmacology, University of Minnesota, United States
| | | |
Collapse
|
3
|
Pouncey DL, Barnette DA, Sinnott RW, Phillips SJ, Flynn NR, Hendrickson HP, Swamidass SJ, Miller GP. Discovery of Novel Reductive Elimination Pathway for 10-Hydroxywarfarin. Front Pharmacol 2022; 12:805133. [PMID: 35095511 PMCID: PMC8793337 DOI: 10.3389/fphar.2021.805133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 12/20/2021] [Indexed: 11/20/2022] Open
Abstract
Coumadin (R/S-warfarin) anticoagulant therapy is highly efficacious in preventing the formation of blood clots; however, significant inter-individual variations in response risks over or under dosing resulting in adverse bleeding events or ineffective therapy, respectively. Levels of pharmacologically active forms of the drug and metabolites depend on a diversity of metabolic pathways. Cytochromes P450 play a major role in oxidizing R- and S-warfarin to 6-, 7-, 8-, 10-, and 4′-hydroxywarfarin, and warfarin alcohols form through a minor metabolic pathway involving reduction at the C11 position. We hypothesized that due to structural similarities with warfarin, hydroxywarfarins undergo reduction, possibly impacting their pharmacological activity and elimination. We modeled reduction reactions and carried out experimental steady-state reactions with human liver cytosol for conversion of rac-6-, 7-, 8-, 4′-hydroxywarfarin and 10-hydroxywarfarin isomers to the corresponding alcohols. The modeling correctly predicted the more efficient reduction of 10-hydroxywarfarin over warfarin but not the order of the remaining hydroxywarfarins. Experimental studies did not indicate any clear trends in the reduction for rac-hydroxywarfarins or 10-hydroxywarfarin into alcohol 1 and 2. The collective findings indicated the location of the hydroxyl group significantly impacted reduction selectivity among the hydroxywarfarins, as well as the specificity for the resulting metabolites. Based on studies with R- and S-7-hydroxywarfarin, we predicted that all hydroxywarfarin reductions are enantioselective toward R substrates and enantiospecific for S alcohol metabolites. CBR1 and to a lesser extent AKR1C3 reductases are responsible for those reactions. Due to the inefficiency of reactions, only reduction of 10-hydroxywarfarin is likely to be important in clearance of the metabolite. This pathway for 10-hydroxywarfarin may have clinical relevance as well given its anticoagulant activity and capacity to inhibit S-warfarin metabolism.
Collapse
Affiliation(s)
- Dakota L Pouncey
- Department of Biochemistry and Molecular Biology, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Dustyn A Barnette
- Department of Biochemistry and Molecular Biology, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Riley W Sinnott
- Department of Biochemistry and Molecular Biology, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Sarah J Phillips
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Noah R Flynn
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, United States
| | - Howard P Hendrickson
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR, United States.,Department of Pharmaceutical Social and Administrative Sciences, McWhorter School of Pharmacy, Samford University, Birmingham, AL, United States
| | - S Joshua Swamidass
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, United States
| | - Grover P Miller
- Department of Biochemistry and Molecular Biology, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| |
Collapse
|
4
|
Alshogran OY. Warfarin Dosing and Outcomes in Chronic Kidney Disease: A Closer Look at Warfarin Disposition. Curr Drug Metab 2019; 20:633-645. [PMID: 31267868 DOI: 10.2174/1389200220666190701095807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 04/02/2019] [Accepted: 06/12/2019] [Indexed: 11/22/2022]
Abstract
BACKGROUND Chronic Kidney Disease (CKD) is a prevalent worldwide health problem. Patients with CKD are more prone to developing cardiovascular complications such as atrial fibrillation and stroke. This warrants the use of oral anticoagulants, such as warfarin, in this population. While the efficacy and safety of warfarin in this setting remain controversial, a growing body of evidence emphasizes that warfarin use in CKD can be problematic. This review discusses 1) warfarin use, dosing and outcomes in CKD patients; and 2) possible pharmacokinetic mechanisms for altered warfarin dosing and response in CKD. METHODS Structured search and review of literature articles evaluating warfarin dosing and outcomes in CKD. Data and information about warfarin metabolism, transport, and pharmacokinetics in CKD were also analyzed and summarized. RESULTS The literature data suggest that changes in warfarin pharmacokinetics such as protein binding, nonrenal clearance, the disposition of warfarin metabolites may partially contribute to altered warfarin dosing and response in CKD. CONCLUSION Although the evidence to support warfarin use in advanced CKD is still unclear, this synthesis of previous findings may help in improving optimized warfarin therapy in CKD settings.
Collapse
Affiliation(s)
- Osama Y Alshogran
- Department of Clinical Pharmacy, Faculty of Pharmacy, Jordan University of Science and Technology, Irbid, Jordan
| |
Collapse
|
5
|
Meech R, Hu DG, McKinnon RA, Mubarokah SN, Haines AZ, Nair PC, Rowland A, Mackenzie PI. The UDP-Glycosyltransferase (UGT) Superfamily: New Members, New Functions, and Novel Paradigms. Physiol Rev 2019; 99:1153-1222. [DOI: 10.1152/physrev.00058.2017] [Citation(s) in RCA: 103] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
UDP-glycosyltransferases (UGTs) catalyze the covalent addition of sugars to a broad range of lipophilic molecules. This biotransformation plays a critical role in elimination of a broad range of exogenous chemicals and by-products of endogenous metabolism, and also controls the levels and distribution of many endogenous signaling molecules. In mammals, the superfamily comprises four families: UGT1, UGT2, UGT3, and UGT8. UGT1 and UGT2 enzymes have important roles in pharmacology and toxicology including contributing to interindividual differences in drug disposition as well as to cancer risk. These UGTs are highly expressed in organs of detoxification (e.g., liver, kidney, intestine) and can be induced by pathways that sense demand for detoxification and for modulation of endobiotic signaling molecules. The functions of the UGT3 and UGT8 family enzymes have only been characterized relatively recently; these enzymes show different UDP-sugar preferences to that of UGT1 and UGT2 enzymes, and to date, their contributions to drug metabolism appear to be relatively minor. This review summarizes and provides critical analysis of the current state of research into all four families of UGT enzymes. Key areas discussed include the roles of UGTs in drug metabolism, cancer risk, and regulation of signaling, as well as the transcriptional and posttranscriptional control of UGT expression and function. The latter part of this review provides an in-depth analysis of the known and predicted functions of UGT3 and UGT8 enzymes, focused on their likely roles in modulation of levels of endogenous signaling pathways.
Collapse
Affiliation(s)
- Robyn Meech
- Department of Clinical Pharmacology and Flinders Centre for Innovation in Cancer, Flinders University College of Medicine and Public Health, Flinders Medical Centre, Bedford Park, South Australia, Australia
| | - Dong Gui Hu
- Department of Clinical Pharmacology and Flinders Centre for Innovation in Cancer, Flinders University College of Medicine and Public Health, Flinders Medical Centre, Bedford Park, South Australia, Australia
| | - Ross A. McKinnon
- Department of Clinical Pharmacology and Flinders Centre for Innovation in Cancer, Flinders University College of Medicine and Public Health, Flinders Medical Centre, Bedford Park, South Australia, Australia
| | - Siti Nurul Mubarokah
- Department of Clinical Pharmacology and Flinders Centre for Innovation in Cancer, Flinders University College of Medicine and Public Health, Flinders Medical Centre, Bedford Park, South Australia, Australia
| | - Alex Z. Haines
- Department of Clinical Pharmacology and Flinders Centre for Innovation in Cancer, Flinders University College of Medicine and Public Health, Flinders Medical Centre, Bedford Park, South Australia, Australia
| | - Pramod C. Nair
- Department of Clinical Pharmacology and Flinders Centre for Innovation in Cancer, Flinders University College of Medicine and Public Health, Flinders Medical Centre, Bedford Park, South Australia, Australia
| | - Andrew Rowland
- Department of Clinical Pharmacology and Flinders Centre for Innovation in Cancer, Flinders University College of Medicine and Public Health, Flinders Medical Centre, Bedford Park, South Australia, Australia
| | - Peter I. Mackenzie
- Department of Clinical Pharmacology and Flinders Centre for Innovation in Cancer, Flinders University College of Medicine and Public Health, Flinders Medical Centre, Bedford Park, South Australia, Australia
| |
Collapse
|
6
|
Novel isomeric metabolite profiles correlate with warfarin metabolism phenotype during maintenance dosing in a pilot study of 29 patients. Blood Coagul Fibrinolysis 2018; 29:602-612. [PMID: 30334816 DOI: 10.1097/mbc.0000000000000752] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
: For this pilot study, we leveraged metabolite patterns for warfarin patients to more accurately assess clinically relevant differences in drug metabolism. We tested our hypothesis that plasma metabolite levels correlate with the influence of clinical factors on R-warfarin and S-warfarin metabolism (warfarin metabolic phenotype). We recruited 29 patients receiving a maintenance dose and testing within targeted therapeutic range. We determined their CYP2C9 and vitamin K epoxide reductase genotype and profiled 14 isomeric forms of warfarin and its metabolites. We employed three novel types of clearance ratios using analyte levels to perform multiple-linear regression analyses with clinical factors impacting drug metabolism and dose-responses. Competitive clearance ratios correlated with seven clinical factors including lifestyle choices (smoking), genetics (CYP2C9 and vitamin K epoxide reductase 1), and drug interactions (omeprazole) along with age, weight, and malignancy. Significant competitive clearance ratio correlations (P = 0.04 to < 0.001) explained 21-95% variability. Their performances surpassed that of oxidative and metabolic clearance ratios based on the number and significance of correlations. Competitive clearance ratios may accurately assess significance of factors on maintaining levels of pharmacologically active forms of the drug and metabolites related to dose-responses and thus provide a strategy to minimize adverse events and improve safety during anticoagulant therapy. This unique capacity could provide a strategy in a future, higher power study with a larger cohort of patients to more accurately assess the significance of clinical factors on active drug levels contributing to warfarin dose-responses.
Collapse
|
7
|
Takeda K, Ikenaka Y, Tanaka KD, Nakayama SMM, Tanikawa T, Mizukawa H, Ishizuka M. Investigation of hepatic warfarin metabolism activity in rodenticide-resistant black rats (Rattus rattus) in Tokyo by in situ liver perfusion. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2018; 148:42-49. [PMID: 29891376 DOI: 10.1016/j.pestbp.2018.03.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2017] [Revised: 02/26/2018] [Accepted: 03/25/2018] [Indexed: 06/08/2023]
Abstract
Anti-blood coagulation rodenticides, such as warfarin, have been used all over the world. They inhibit vitamin K epoxide reductase (VKOR), which is necessary for producing several blood clotting factors. This inhibition by rodenticides results in lethal hemorrhage in rodents. However, heavy usage of these agents has led to the appearance of rodenticide-resistant rats. There are two major mechanisms underlying this resistance, i.e., mutation of the target enzyme of warfarin, VKOR, and enhanced metabolism of warfarin. However, there have been few studies regarding the hepatic metabolism of warfarin, which should be related to resistance. To investigate warfarin metabolism in resistant rats, in situ liver perfusion of warfarin was performed with resistant black rats (Rattus rattus) from Tokyo, Japan. Liver perfusion is an in situ methodology that can reveal hepatic function specifically with natural composition of the liver. The results indicated enhanced hepatic warfarin hydroxylation activity compared with sensitive black rats. On the other hand, in an in vitro microsomal warfarin metabolism assay to investigate kinetic parameters of cytochrome P450, which plays a major role in warfarin hydroxylation, the Vmax of resistant rats was slightly but significantly higher compared to the results obtained in the in situ study. These results indicated that another factor like electron donators may also contribute to the enhanced metabolism in addition to high expression of cytochrome P450.
Collapse
Affiliation(s)
- Kazuki Takeda
- Laboratory of Toxicology, Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Kita-18 Nishi-9, Kita-ku, Sapporo 060-0818, Japan
| | - Yoshinori Ikenaka
- Laboratory of Toxicology, Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Kita-18 Nishi-9, Kita-ku, Sapporo 060-0818, Japan; Water Research Group, Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa
| | - Kazuyuki D Tanaka
- Technical Research Laboratory, IKARI SHODOKU CO. LTD., 1-12-3 Akanehama, Narashino, Chiba 275-0024, Japan
| | - Shouta M M Nakayama
- Laboratory of Toxicology, Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Kita-18 Nishi-9, Kita-ku, Sapporo 060-0818, Japan
| | - Tsutomu Tanikawa
- Technical Research Laboratory, IKARI SHODOKU CO. LTD., 1-12-3 Akanehama, Narashino, Chiba 275-0024, Japan
| | - Hazuki Mizukawa
- Laboratory of Toxicology, Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Kita-18 Nishi-9, Kita-ku, Sapporo 060-0818, Japan
| | - Mayumi Ishizuka
- Laboratory of Toxicology, Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Kita-18 Nishi-9, Kita-ku, Sapporo 060-0818, Japan.
| |
Collapse
|
8
|
Kim SY, Jones DR, Kang JY, Yun CH, Miller GP. Regioselectivity significantly impacts microsomal glucuronidation efficiency of R/S-6, 7-, and 8-hydroxywarfarin. Xenobiotica 2018. [PMID: 29543105 DOI: 10.1080/00498254.2018.1451668] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Coumadin (R/S-warfarin) metabolism plays a critical role in patient response to anticoagulant therapy. Several cytochrome P450s oxidize warfarin into R/S-6-, 7-, 8-, 10, and 4'-hydroxywarfarin that can undergo subsequent glucuronidation by UDP-glucuronosyltransferases (UGTs); however, current studies on recombinant UGTs cannot be adequately extrapolated to microsomal glucuronidation capacities for the liver. Herein, we estimated the capacity of the average human liver to glucuronidate hydroxywarfarin and identified UGTs responsible for those metabolic reactions through inhibitor phenotyping. There was no observable activity toward R/S-warfarin, R/S-10-hydroxywarfarin or R/S-4'-hydroxywarfarin. The observed metabolic efficiencies (Vmax/Km) toward R/S-6-, 7-, and especially 8-hydroxywarfarin indicated a high glucuronidation capacity to metabolize these compounds. UGTs demonstrated strong regioselectivity toward the hydroxywarfarins. UGT1A6 and UGT1A1 played a major role in R/S-6- and 7-hydroxywarfarin glucuronidation, respectively, whereas UGT1A9 accounted for almost all of the generation of the R/S-8-hydroxywarfarin glucuronide. In summary, these studies expanded insights to glucuronidation of hydroxywarfarins by pooled human liver microsomes, novel roles for UGT1A6 and 1A9, and the overall degree of regioselectivity for the UGT reactions.
Collapse
Affiliation(s)
- So-Young Kim
- a School of Biological Sciences and Technology , Chonnam National University , Gwangju , Republic of Korea
| | - Drew R Jones
- b Department of Biochemistry and Molecular Biology , University of Arkansas for Medical Sciences , Little Rock , AR , USA
| | - Ji-Yeon Kang
- a School of Biological Sciences and Technology , Chonnam National University , Gwangju , Republic of Korea
| | - Chul-Ho Yun
- a School of Biological Sciences and Technology , Chonnam National University , Gwangju , Republic of Korea
| | - Grover P Miller
- a School of Biological Sciences and Technology , Chonnam National University , Gwangju , Republic of Korea
| |
Collapse
|
9
|
Wang X, Jiang C, Wu X, Zou P, Wu Z. Substrate Selectivity for UDP-glucuronosyltransferase1A8 using the Pharmacophore Approach. INT J PHARMACOL 2018. [DOI: 10.3923/ijp.2018.320.328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
10
|
An SH, Chang BC, Lee KE, Gwak HS. Influence of UDP-Glucuronosyltransferase Polymorphisms on Stable Warfarin Doses in Patients with Mechanical Cardiac Valves. Cardiovasc Ther 2016. [PMID: 26223945 DOI: 10.1111/1755-5922.12147] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
AIM This study aimed to evaluate the effect of uridine diphosphate (UDP)-glucuronosyltransferase (UGT) polymorphisms on warfarin dosing requirements in patients with mechanical cardiac valves. METHODS A total of 191 patients with stable warfarin doses from the EAST Group of Warfarin were included in this study. The influence of genetic polymorphisms on stable warfarin doses was investigated by genotyping 6 single nucleotide polymorphisms (SNPs): vitamin K epoxide reductase complex 1 (VKORC1) rs9934438, cytochrome P450 (CYP) 2C9 rs1057910, CYP4F2 rs2108622, and UGT1A1 (rs887829, rs4148323, and rs4124874). An additional subgroup analysis was carried out using patients with wild-type homozygote carriers of CYP2C9. RESULTS One UGT1A1 SNP of rs887829 (C>T) exhibited significant association with stable warfarin doses in the study population and subgroup. Patients with the T allele in UGT1A1 rs887829 (CT or TT) required higher doses than those with the CC genotype in the study population (6.3 ± 2.4 mg vs. 5.2 ± 1.6 mg, P = 0.003). Similarly, in the subpopulation of AA carriers in the CYP2C9 gene, patients with the T allele required significantly higher doses of warfarin than those with other genotypes of rs887829 (6.5 ± 2.4 vs. 5.3 ± 1.5 mg, P = 0.002). Approximately 45.1% of overall interindividual variability in warfarin dose requirement was explained by the multivariate regression model. VKORC1, CYP2C9, UGT1A1 rs887829, age, and CYP4F2 accounted for 28.2%, 6.6%, 5.5%, 3.0%, and 1.8% of the variability, respectively. CONCLUSION Our results suggest that UGT1A1 could be a determinant of stable warfarin doses.
Collapse
Affiliation(s)
- Sook Hee An
- College of Pharmacy, Wonkwang University, Iksan, Jeonbuk, Korea
| | - Byung Chul Chang
- Department of Thoracic & Cardiovascular Surgery, Yonsei University Medical Center, Seodaemun-gu, Seoul, Korea
| | - Kyung Eun Lee
- College of Pharmacy & Division of Life and Pharmaceutical Sciences, Ewha Womans University, Seodaemun-gu, Seoul, Korea.,College of Pharmacy, Chungbuk National University, Cheongju, Chungbuk, Korea
| | - Hye Sun Gwak
- College of Pharmacy & Division of Life and Pharmaceutical Sciences, Ewha Womans University, Seodaemun-gu, Seoul, Korea
| |
Collapse
|
11
|
Takeda K, Ikenaka Y, Tanikawa T, Tanaka KD, Nakayama SMM, Mizukawa H, Ishizuka M. Novel revelation of warfarin resistant mechanism in roof rats (Rattus rattus) using pharmacokinetic/pharmacodynamic analysis. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2016; 134:1-7. [PMID: 27914534 DOI: 10.1016/j.pestbp.2016.04.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Revised: 04/08/2016] [Accepted: 04/08/2016] [Indexed: 06/06/2023]
Abstract
Roof rats (Rattus rattus) live mainly in human habitats. Heavy use of rodenticides, such as warfarin, has led to the development of drug resistance, making pest control difficult. There have been many reports regarding mutations of vitamin K epoxide reductase (VKOR), the target enzyme of warfarin, in resistant rats. However, it has been suggested there are other mechanisms of warfarin resistance. To confirm these possibilities, closed colonies of warfarin-susceptible roof rats (S) and resistant rats from Tokyo (R) were established, and the pharmacokinetics/pharmacodynamics of warfarin in rats from both colonies was investigated. R rats had low levels of warfarin in serum and high clearance activity. These rats can rapidly metabolize warfarin by hydroxylation. The levels of accumulation in the organs were lower than those of S rats. R rats administered warfarin showed high expression levels of CYP2B, 2C, and 3A, which play roles in warfarin hydroxylation, and may explain the high clearance ability of R rats. The mechanism of warfarin resistance in roof rats from Tokyo involved not only mutation of VKOR but also high clearance ability due to high levels of CYP2B, 2C and 3A expression possibly induced by warfarin.
Collapse
Affiliation(s)
- Kazuki Takeda
- Laboratory of Toxicology, Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Kita-18 Nishi-9, Kita-ku, Sapporo 060-0818, Japan
| | - Yoshinori Ikenaka
- Laboratory of Toxicology, Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Kita-18 Nishi-9, Kita-ku, Sapporo 060-0818, Japan; Water Research Group, Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa
| | - Tsutomu Tanikawa
- Technical Research Laboratory, Ikari Corporation, Chiba 260-0844, Japan
| | - Kazuyuki D Tanaka
- Technical Research Laboratory, Ikari Corporation, Chiba 260-0844, Japan
| | - Shouta M M Nakayama
- Laboratory of Toxicology, Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Kita-18 Nishi-9, Kita-ku, Sapporo 060-0818, Japan
| | - Hazuki Mizukawa
- Laboratory of Toxicology, Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Kita-18 Nishi-9, Kita-ku, Sapporo 060-0818, Japan
| | - Mayumi Ishizuka
- Laboratory of Toxicology, Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Kita-18 Nishi-9, Kita-ku, Sapporo 060-0818, Japan.
| |
Collapse
|
12
|
Liu AC, Zhao LX, Yu SW, Lou HX. Pre-treatment with puerarin affects pharmacokinetics of warfarin, but not clopidogrel, in experimental rats. Chin J Nat Med 2016; 13:257-63. [PMID: 25908622 DOI: 10.1016/s1875-5364(15)30012-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2014] [Indexed: 12/26/2022]
Abstract
The present study was designed to determine the effects of puerarin pre-treatment on the pharmacokinetics of the oral anticoagulant agent warfarin and the antiplatelet agent clopidogrel in rats. In the treatment group, rats was gavaged with warfarin or clopidogrel after repeated treatment with puerarin at intraperitoneal doses of 20, 60, or 200 mg·kg(-1) for 7 days, while rats in the control group were administrated only with the same dose warfarin or clopidogrel. Plasma samples were obtained at the prescribed times and analyzed by liquid chromatography tandem mass spectrometry (LC-MS/MS). The results showed that rats treated with puerarin at all the test doses of 20, 60 and 200 mg·kg(-1) were found to affect the pharmacokinetics of warfarin, but not clopidogrel, suggesting a potential herb-drug interaction between puerarin and warfarin.
Collapse
Affiliation(s)
- An-Chang Liu
- Qilu hospital of Shandong University, Jinan 250012, China
| | - Li-Xia Zhao
- Qilu hospital of Shandong University, Jinan 250012, China
| | - Shu-Wen Yu
- Jinan Central Hospital Affiliated to Shandong University, Jinan 250011, China
| | - Hong-Xiang Lou
- School of Pharmaceutical Sciences, Shandong University, Jinan 250012, China.
| |
Collapse
|
13
|
Lu J, Zhang Y, Li H, Yu J, Liu S. Electrochemically driven drug metabolism via a CYP1A2-UGT1A10 bienzyme confined in a graphene nano-cage. Chem Commun (Camb) 2015; 50:13896-9. [PMID: 25264962 DOI: 10.1039/c4cc06200k] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A graphene nano-cage with regulatable space for the assembly of a cytochrome P450 1A2-UDP-glucuronosyltransferase 1A10 bienzyme complex has been constructed via a click reaction, and successfully used to study drug sequential metabolism using an electrochemically-driven method.
Collapse
Affiliation(s)
- Jusheng Lu
- Jiangsu Province Hi-Tech Key Laboratory for Bio-medical Research, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China.
| | | | | | | | | |
Collapse
|
14
|
Sun H, Zhang T, Wu Z, Wu B. Warfarin is an effective modifier of multiple UDP-glucuronosyltransferase enzymes: evaluation of its potential to alter the pharmacokinetics of zidovudine. J Pharm Sci 2014; 104:244-56. [PMID: 25393417 DOI: 10.1002/jps.24250] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Revised: 10/01/2014] [Accepted: 10/17/2014] [Indexed: 12/23/2022]
Abstract
In this study, we aimed to determine the modulatory effects of warfarin (an extensively used anticoagulant drug) and its metabolites on UDP-glucuronosyltransferase (UGT) activity and to assess the potential of warfarin to alter the pharmacokinetics of zidovudine (AZT). The effects of warfarin and its metabolites on glucuronidation were determined using human and rat liver microsomes (HLM and RLM) as well as expressed UGTs. The mechanisms of warfarin-UGT interactions were explored through kinetic characterization and modeling. Pharmacokinetic studies with rats were performed to evaluate the potential of warfarin to alter the pharmacokinetics of AZT. We found that warfarin was an effective modifier of a panel of UGT enzymes. The effects of warfarin on glucuronidation were inhibitory for UGT1A1, 2B7, and 2B17, but activating for UGT1A3. Mixed effects were observed for UGT1A7 and 1A9. Consistent with its inhibitory effects on UGT2B7 activity, warfarin inhibited AZT glucuronidation in HLM (Ki = 74.9-96.3 μM) and RLM (Ki = 190-230 μM). Inhibition of AZT glucuronidation by UGT2B7, HLM, and RLM was also observed with several hydroxylated metabolites of warfarin. Moreover, the systemic exposure (AUC) of AZT in rats was increased by a 1.5- to 2.1-fold upon warfarin coadministration. The elevated AUC was associated with suppressed glucuronidation that was probably attained through a combined action of warfarin and its hydroxylated metabolites. In conclusion, the activities of multiple UGT enzymes can be modulated by warfarin and the nature of modulation was isoform dependent. Also, pharmacokinetic interactions of zidovudine with warfarin were highly possible through inhibition of UGT metabolism.
Collapse
Affiliation(s)
- Hua Sun
- Division of Pharmaceutics, College of Pharmacy, Jinan University, Guangzhou, 510632, China
| | | | | | | |
Collapse
|
15
|
Hu DG, Meech R, McKinnon RA, Mackenzie PI. Transcriptional regulation of human UDP-glucuronosyltransferase genes. Drug Metab Rev 2014; 46:421-58. [PMID: 25336387 DOI: 10.3109/03602532.2014.973037] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Glucuronidation is an important metabolic pathway for many small endogenous and exogenous lipophilic compounds, including bilirubin, steroid hormones, bile acids, carcinogens and therapeutic drugs. Glucuronidation is primarily catalyzed by the UDP-glucuronosyltransferase (UGT) 1A and two subfamilies, including nine functional UGT1A enzymes (1A1, 1A3-1A10) and 10 functional UGT2 enzymes (2A1, 2A2, 2A3, 2B4, 2B7, 2B10, 2B11, 2B15, 2B17 and 2B28). Most UGTs are expressed in the liver and this expression relates to the major role of hepatic glucuronidation in systemic clearance of toxic lipophilic compounds. Hepatic glucuronidation activity protects the body from chemical insults and governs the therapeutic efficacy of drugs that are inactivated by UGTs. UGT mRNAs have also been detected in over 20 extrahepatic tissues with a unique complement of UGT mRNAs seen in almost every tissue. This extrahepatic glucuronidation activity helps to maintain homeostasis and hence regulates biological activity of endogenous molecules that are primarily inactivated by UGTs. Deciphering the molecular mechanisms underlying tissue-specific UGT expression has been the subject of a large number of studies over the last two decades. These studies have shown that the constitutive and inducible expression of UGTs is primarily regulated by tissue-specific and ligand-activated transcription factors (TFs) via their binding to cis-regulatory elements (CREs) in UGT promoters and enhancers. This review first briefly summarizes published UGT gene transcriptional studies and the experimental models and tools utilized in these studies, and then describes in detail the TFs and their respective CREs that have been identified in the promoters and/or enhancers of individual UGT genes.
Collapse
Affiliation(s)
- Dong Gui Hu
- Department of Clinical Pharmacology and Flinders Centre for Innovation in Cancer, Flinders University School of Medicine, Flinders Medical Centre , Bedford Park, SA , Australia
| | | | | | | |
Collapse
|
16
|
Pugh CP, Pouncey DL, Hartman JH, Nshimiyimana R, Desrochers LP, Goodwin TE, Boysen G, Miller GP. Multiple UDP-glucuronosyltransferases in human liver microsomes glucuronidate both R- and S-7-hydroxywarfarin into two metabolites. Arch Biochem Biophys 2014; 564:244-53. [PMID: 25447818 DOI: 10.1016/j.abb.2014.10.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 10/08/2014] [Accepted: 10/15/2014] [Indexed: 01/20/2023]
Abstract
The widely used anticoagulant Coumadin (R/S-warfarin) undergoes oxidation by cytochromes P450 into hydroxywarfarins that subsequently become conjugated for excretion in urine. Hydroxywarfarins may modulate warfarin metabolism transcriptionally or through direct inhibition of cytochromes P450 and thus, UGT action toward hydroxywarfarin elimination may impact levels of the parent drugs and patient responses. Nevertheless, relatively little is known about conjugation by UDP-glucuronosyltransferases in warfarin metabolism. Herein, we identified probable conjugation sites, kinetic mechanisms and hepatic UGT isoforms involved in microsomal glucuronidation of R- and S-7-hydroxywarfarin. Both compounds underwent glucuronidation at C4 and C7 hydroxyl groups based on elution properties and spectral characteristics. Their formation demonstrated regio- and enantioselectivity by UGTs and resulted in either Michaelis-Menten or substrate inhibition kinetics. Glucuronidation at the C7 hydroxyl group occurred more readily than at the C4 group, and the reaction was overall more efficient for R-7-hydroxywarfarin due to higher affinity and rates of turnover. The use of these mechanisms and parameters to model in vivo clearance demonstrated that contributions of substrate inhibition would lead to underestimation of metabolic clearance than that predicted by Michaelis-Menten kinetics. Lastly, these processes were driven by multiple UGTs indicating redundancy in glucuronidation pathways and ultimately metabolic clearance of R- and S-7-hydroxywarfarin.
Collapse
Affiliation(s)
- C Preston Pugh
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Dakota L Pouncey
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR, USA; Department of Chemistry, Hendrix College, Conway, AR, USA
| | - Jessica H Hartman
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | | | | | | | - Gunnar Boysen
- Department of Environmental and Occupational Health, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Grover P Miller
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
| |
Collapse
|
17
|
Fang ZZ, Cao YF, Hu CM, Hong M, Sun XY, Ge GB, Liu Y, Zhang YY, Yang L, Sun HZ. Structure–inhibition relationship of ginsenosides towards UDP-glucuronosyltransferases (UGTs). Toxicol Appl Pharmacol 2013; 267:149-54. [DOI: 10.1016/j.taap.2012.12.019] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Revised: 12/16/2012] [Accepted: 12/24/2012] [Indexed: 10/27/2022]
|
18
|
Fedejko-Kap B, Bratton SM, Finel M, Radominska-Pandya A, Mazerska Z. Role of human UDP-glucuronosyltransferases in the biotransformation of the triazoloacridinone and imidazoacridinone antitumor agents C-1305 and C-1311: highly selective substrates for UGT1A10. Drug Metab Dispos 2012; 40:1736-43. [PMID: 22659092 DOI: 10.1124/dmd.112.045401] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
5-Diethylaminoethylamino-8-hydroxyimidazoacridinone, C-1311 (NSC-645809), is an antitumor agent shown to be effective against breast cancer in phase II clinical trials. A similar compound, 5-dimethylaminopropylamino-8-hydroxytriazoloacridinone, C-1305, shows high activity against experimental tumors and is expected to have even more beneficial pharmacological properties than C-1311. Previously published studies showed that these compounds are not substrates for cytochrome P450s; however, they do contain functional groups that are common targets for glucuronidation. Therefore, the aim of this work was to identify the human UDP-glucuronosyltransferases (UGTs) able to glucuronidate these two compounds. High-performance liquid chromatography analysis was used to examine the activities of human recombinant UGT1A and UGT2B isoforms and microsomes from human liver [human liver microsomes (HLM)], whole human intestinal mucosa [human intestinal microsomes (HIM)], and seven isolated segments of human gastrointestinal tract. Recombinant extrahepatic UGT1A10 glucuronidated 8-hydroxyl groups with the highest catalytic efficiency compared with other recombinant UGTs, V(max)/K(m) = 27.2 and 8.8 μl · min⁻¹ · mg protein⁻¹, for C-1305 and C-1311, respectively. In human hepatic and intestinal microsomes (HLM and HIM, respectively), high variability in UGT activities was observed among donors and for different regions of intestinal tract. However, both compounds underwent UGT-mediated metabolism to 8-O-glucuronides by microsomes from both sources with comparable efficiency; V(max)/K(m) values were from 4.0 to 5.5 μl · min⁻¹ · mg protein⁻¹. In summary, these studies suggest that imid azoacridinone and triazoloacridinone drugs are glucuronidated in human liver and intestine in vivo and may form the basis for future translational studies of the potential role of UGTs in resistance to these drugs.
Collapse
Affiliation(s)
- Barbara Fedejko-Kap
- Department of Pharmaceutical Technology and Biochemistry, Chemical Faculty, Gdansk University of Technology, Gdansk, Poland
| | | | | | | | | |
Collapse
|
19
|
Sawamura J, Kozaki K, Mochizuki S, Ishigooka J. Possible Interaction Between Milnacipran and Warfarin Potassium. J Clin Pharmacol 2012; 52:780-1. [DOI: 10.1177/0091270011398244] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
20
|
Höglund C, Sneitz N, Radominska-Pandya A, Laakonen L, Finel M. Phenylalanine 93 of the human UGT1A10 plays a major role in the interactions of the enzyme with estrogens. Steroids 2011; 76:1465-73. [PMID: 21846474 PMCID: PMC3188330 DOI: 10.1016/j.steroids.2011.07.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2011] [Revised: 07/28/2011] [Accepted: 07/29/2011] [Indexed: 10/17/2022]
Abstract
Little is currently known about the substrate binding site of the human UDP-glucuronosyltransferases (UGTs) and the structural elements that affect their complex substrate selectivity. In order to further understand and extend our earlier findings with phenylalanines 90 and 93 of UGT1A10, we have replaced each of them with Gly, Ala, Val, Leu, Ile or Tyr, and tested the activity of the resulting 12 mutants toward eight different substrates. Apart from scopoletin glucuronidation, the F90 mutants other than F90L were nearly inactive, while the F93 mutants' activity was strongly substrate dependent. Hence, F93L displayed high entacapone and 1-naphthol glucuronidation rates, whereas F93G, which was nearly inactive in entacapone glucuronidation, was highly active toward estradiol, estriol and even ethinylestradiol, a synthetic estrogen that is a poor substrate for the wild-type UGT1A10. Kinetic analyses of 4-nitrophenol, estradiol and ethinylestradiol glucuronidation by the mutants that catalyzed the respective reactions at considerable rates, revealed increased K(m) values for 4-nitrophenol and estradiol in all the mutants, whilst the K(m) values of F93G and F93A for ethinylestradiol were lower than in control UGT1A10. Based on the activity results and a new molecular model of UGT1A10, it is suggested that both F90 and F93 are located in a surface helix at the far end of the substrate binding site. Nevertheless, only F93 directly affects the selectivity of UGT1A10 toward large and rigid estrogens, particularly those with substitutions at the D ring. The effects of F93 mutations on the glucuronidation of smaller or less rigid substrates are indirect, however.
Collapse
Affiliation(s)
- Camilla Höglund
- Centre for Drug Research, Faculty of Pharmacy, P.O. Box 56 (Viikinkaari 5), FI-00014 University of Helsinki, Finland
- Division of Pharmaceutical Chemistry, Faculty of Pharmacy, P.O. Box 56 (Viikinkaari 5), FI-00014 University of Helsinki, Finland
| | - Nina Sneitz
- Centre for Drug Research, Faculty of Pharmacy, P.O. Box 56 (Viikinkaari 5), FI-00014 University of Helsinki, Finland
- Division of Pharmaceutical Chemistry, Faculty of Pharmacy, P.O. Box 56 (Viikinkaari 5), FI-00014 University of Helsinki, Finland
| | - Anna Radominska-Pandya
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA (A.R.-P.)
| | - Liisa Laakonen
- Centre for Drug Research, Faculty of Pharmacy, P.O. Box 56 (Viikinkaari 5), FI-00014 University of Helsinki, Finland
| | - Moshe Finel
- Centre for Drug Research, Faculty of Pharmacy, P.O. Box 56 (Viikinkaari 5), FI-00014 University of Helsinki, Finland
| |
Collapse
|
21
|
Saengtienchai A, Ikenaka Y, Watanabe K, Ishida T, Ishizuka M. Comparative metabolism of warfarin in rats and chickens. Poult Sci 2011; 90:2775-81. [PMID: 22080016 DOI: 10.3382/ps.2010-01257] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Warfarin, a coumarin rodenticide, is commonly used worldwide for rodent control, and is often reported as the cause for poisoning accidents in nontarget animals, in particular bird species. However, the metabolism of warfarin in birds is still unclear. In a previous study, we found an unknown warfarin metabolite in chicken cytosolic fractions. In the present study, we aimed to clarify the cytosolic warfarin metabolites in chickens compared with those in rats. The cytosol fractions of both chicken and rat livers showed the metabolic activity of 2 diastereomers and 2 enantiomers of warfarin alcohol. In chicken cytosol, we found that the production level of (S)-warfarin-(S)-alcohol was markedly higher (32-fold) than that in rat cytosol. From the results of the inhibition assay, we finally suggest that aldehyde oxidase may mainly contribute to the warfarin alcohol products in chicken cytosol.
Collapse
Affiliation(s)
- A Saengtienchai
- Department of Environmental Veterinary Sciences, Hokkaido University, Sapporo, Japan
| | | | | | | | | |
Collapse
|
22
|
Bratton SM, Mosher CM, Khallouki F, Finel M, Court MH, Moran JH, Radominska-Pandya A. Analysis of R- and S-hydroxywarfarin glucuronidation catalyzed by human liver microsomes and recombinant UDP-glucuronosyltransferases. J Pharmacol Exp Ther 2011; 340:46-55. [PMID: 21972237 DOI: 10.1124/jpet.111.184721] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Coumadin (R-, S-warfarin) is a challenging drug to accurately dose, both initially and for maintenance, because of its narrow therapeutic range and wide interpatient variability and is typically administered as a racemic (Rac) mixture, which complicates the biotransformation pathways. The goal of the current work was to identify the human UDP-glucuronosyltransferases (UGTs) involved in the glucuronidation of the separated R- and S-enantiomers of 6-, 7-, and 8-hydroxywarfarin and the possible interactions between these enantiomers. The kinetic and inhibition constants for human recombinant 1A family UGTs toward these separated enantiomers have been assessed using high-performance liquid chromatography (HPLC)-UV-visible analysis, and product confirmations have been made using HPLC-mass spectrometry/mass spectrometry. We found that separated R- and S-enantiomers of 6-, 7-, and 8-hydroxywarfarin demonstrate significantly different glucuronidation kinetics and can be mutually inhibitory. In some cases significant substrate inhibition was observed, as shown by K(m), V(max), and K(i), comparisons. In particular, UGT1A1 and extrahepatic UGT1A10 have significantly higher capacities than other isoforms for S-7-hydroxywarfarin and R-7-hydroxywarfarin glucuronidation, respectively. Activity data generated using a set of well characterized human liver microsomes supported the recombinant enzyme data, suggesting an important (although not exclusive) role for UGT1A1 in glucuronidation of the main warfarin metabolites, including Rac-6- and 7-hydroxywarfarin and their R- and S-enantiomers in the liver. This is the first demonstration that the R- and S-enantiomers of hydroxywarfarins are glucuronidated, with significantly different enzymatic affinity and capacity, and supports the importance of UGT1A1 as the major hepatic isoform involved.
Collapse
Affiliation(s)
- Stacie M Bratton
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | | | | | | | | | | | | |
Collapse
|
23
|
Abstract
Inhibition of enzyme activity at high substrate concentrations, so-called "substrate inhibition," is commonly observed and has been recognized in drug metabolism reactions since the last decade. Although the importance of such "atypical" kinetics in vivo remains poorly understood, a substrate with substrate inhibition kinetics has been shown to unconventionally alter the metabolism of other substrates. In recent years, it is becoming increasingly evident that the mechanisms for substrate inhibition are highly complex, which are possibly contributed by multiple (at least two) binding sites within the enzyme protein, the formation of a ternary dead-end enzyme complex, and/or the ligand-induced changes in enzyme conformation. This review primarily discusses the mechanisms for substrate inhibition displayed by the important drug-metabolizing enzymes, such as cytochrome p450s, UDP-glucuronyltransferases, and sulfotransferases. Kinetic modeling of substrate inhibition in the absence or presence of a modifier is another central issue in this review because of its importance in the determination of kinetic parameters and in vitro/in vivo predictions.
Collapse
Affiliation(s)
- Baojian Wu
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Texas, USA.
| |
Collapse
|
24
|
Peltier-Pain P, Timmons SC, Grandemange A, Benoit E, Thorson JS. Warfarin glycosylation invokes a switch from anticoagulant to anticancer activity. ChemMedChem 2011; 6:1347-50. [PMID: 21714096 PMCID: PMC3217245 DOI: 10.1002/cmdc.201100178] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Indexed: 11/07/2022]
Affiliation(s)
- Pauline Peltier-Pain
- Laboratory for Biosynthetic Chemistry, University of Wisconsin National Cooperative Drug Discovery Group Program, Pharmaceutical Sciences Division, School of Pharmacy, 777 Highland Avenue, Madison, WI 53705, (USA)
| | - Shannon C. Timmons
- Laboratory for Biosynthetic Chemistry, University of Wisconsin National Cooperative Drug Discovery Group Program, Pharmaceutical Sciences Division, School of Pharmacy, 777 Highland Avenue, Madison, WI 53705, (USA)
| | - Agnès Grandemange
- Université de Lyon, VetAgro Sup, USC 1233, INRA, 69280 Marcy l’Etoile, (France)
| | - Etienne Benoit
- Université de Lyon, VetAgro Sup, USC 1233, INRA, 69280 Marcy l’Etoile, (France)
| | - Jon S. Thorson
- Laboratory for Biosynthetic Chemistry, University of Wisconsin National Cooperative Drug Discovery Group Program, Pharmaceutical Sciences Division, School of Pharmacy, 777 Highland Avenue, Madison, WI 53705, (USA)
| |
Collapse
|
25
|
Weigt S, Huebler N, Strecker R, Braunbeck T, Broschard TH. Developmental effects of coumarin and the anticoagulant coumarin derivative warfarin on zebrafish (Danio rerio) embryos. Reprod Toxicol 2011; 33:133-41. [PMID: 21798343 DOI: 10.1016/j.reprotox.2011.07.001] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2011] [Revised: 06/17/2011] [Accepted: 07/02/2011] [Indexed: 11/28/2022]
Abstract
Coumarin and warfarin, two substances which are intensively metabolized in animals and humans, were tested for teratogenicity and embryo lethality in a 3-day in vitro assay using zebrafish embryos. Warfarin is a coumarin derivative, but in contrast to the mother substance warfarin has anticoagulant properties. Both substances produced teratogenic and lethal effects in zebrafish embryos. The LC(50) and EC(50) values for coumarin are 855 μM and 314 μM, respectively; the corresponding values for warfarin are 988 μM and 194 μM. For coumarin, three main or fingerprint endpoints (malformation of head, tail and growth retardation) were identified, whereas malformation of tail was the only fingerprint endpoint of warfarin. The analysis of the ratios between the zebrafish embryo effect concentrations of both substances and human therapeutic plasma concentrations confirmed the teratogenic potential of warfarin, as well as the equivocal status of coumarin.
Collapse
Affiliation(s)
- Stefan Weigt
- Institute of Toxicology, Merck KGaA, 64293 Darmstadt, Germany.
| | | | | | | | | |
Collapse
|
26
|
Li T, Zheng Y, Fu F, Ji H, Chen X, Zhao Y, Zhao D, Li N, Zhang L. Assessment of UDP-glucuronosyltransferase catalyzed formation of Picroside II glucuronide in microsomes of different species and recombinant UGTs. Xenobiotica 2011; 41:530-7. [PMID: 21524190 DOI: 10.3109/00498254.2011.573018] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
This study compared the hepatic glucuronidation of Picroside II in different species and characterized the glucuronidation activities of human intestinal microsomes (HIMs) and recombinant human UDP-glucuronosyltransferases (UGTs) for Picroside II. The rank order of hepatic microsomal glucuronidation activity of Picroside II was rat > mouse > human > dog. The intrinsic clearance of Picroside II hepatic glucuronidation in rat, mouse and dog was about 10.6-, 6.0- and 2.3-fold of that in human, respectively. Among the 12 recombinant human UGTs, UGT1A7, UGT1A8, UGT1A9 and UGT1A10 catalyzed the glucuronidation. UGT1A10, which are expressed in extrahepatic tissues, showed the highest activity of Picroside II glucuronidation (K(m) = 45.1 μM, V(max) = 831.9 pmol/min/mg protein). UGT1A9 played a primary role in glucuronidation in human liver microsomes (HLM; K(m) = 81.3 μM, V(max) = 242.2 pmol/min/mg protein). In addition, both mycophenolic acid (substrate of UGT1A9) and emodin (substrate of UGT1A8 and UGT1A10) could inhibit the glucuronidation of Picroside II with the half maximal inhibitory concentration (IC(50)) values of 173.6 and 76.2 μM, respectively. Enzyme kinetics was also performed in HIMs. The K(m) value of Picroside II glucuronidation was close to that in recombinant human UGT1A10 (K(m) = 58.6 μM, V(max) = 721.4 pmol/min/mg protein). The intrinsic clearance was 5.4-fold of HLMs. Intestinal UGT enzymes play an important role in Picroside II glucuronidation in human.
Collapse
Affiliation(s)
- Tingting Li
- School of Pharmacy, China Pharmaceutical University, Nanjing, P R China
| | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Jones DR, Miller GP. Assays and applications in warfarin metabolism: what we know, how we know it and what we need to know. Expert Opin Drug Metab Toxicol 2011; 7:857-74. [PMID: 21480820 DOI: 10.1517/17425255.2011.576247] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION Coumadin (R/S-warfarin) is the most widely prescribed oral anticoagulant in the world; nevertheless, its clinical use is complicated by unpredictability in dose requirements to achieve and maintain optimal anticoagulation. Variations in warfarin metabolism among patients contribute to unpredictability in therapeutic responses. Studying the clinical relevance of warfarin metabolism poses a significant analytical challenge. Warfarin is given to patients as an equal mixture of R and S enantiomers. Both drugs undergo extensive metabolism through different pathways to generate > 20 structurally similar isomeric metabolites. AREAS COVERED The article discusses how analytical methods have evolved to effectively resolve and quantify individual metabolites. The authors also discuss how the application of these methods has identified clinically relevant metabolic pathways for warfarin and fostered the investigation of clinical biomarkers for patient responses to therapy. The article additionally presents the power of these methods and how aspects of warfarin metabolism have led to the use of warfarin as a phenotyping probe for multiple drug metabolizing enzymes. EXPERT OPINION Progress in these areas has been hampered by shortcomings in analytical methods and a narrow focus on one metabolic pathway. Recent advances in liquid chromatographic-mass spectral methods can rapidly analyze most warfarin metabolites. It is now possible to effectively assess alternate metabolic pathways and expand biomarker analyses for clinical and phenotyping applications.
Collapse
Affiliation(s)
- Drew R Jones
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, 4301 W. Markham, Slot 516, Little Rock, AR 72205, USA
| | | |
Collapse
|
28
|
Lehtonen P, Sten T, Aitio O, Kurkela M, Vuorensola K, Finel M, Kostiainen R. Glucuronidation of racemic O-desmethyltramadol, the active metabolite of tramadol. Eur J Pharm Sci 2010; 41:523-30. [DOI: 10.1016/j.ejps.2010.08.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2010] [Revised: 08/17/2010] [Accepted: 08/18/2010] [Indexed: 01/27/2023]
|
29
|
Jones DR, Kim SY, Guderyon M, Yun CH, Moran JH, Miller GP. Hydroxywarfarin metabolites potently inhibit CYP2C9 metabolism of S-warfarin. Chem Res Toxicol 2010; 23:939-45. [PMID: 20429590 DOI: 10.1021/tx1000283] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Coumadin (R/S-warfarin) anticoagulant therapy poses a risk to over 50 million Americans, in part due to interpersonal variation in drug metabolism. Consequently, it is important to understand how metabolic capacity is influenced among patients. Cytochrome P450s (P450 or CYP for a specific isoform) catalyze the first major step in warfarin metabolism to generate five hydroxywarfarins for each drug enantiomer. These primary metabolites are thought to reach at least 5-fold higher levels in plasma than warfarin. We hypothesized that hydroxywarfarins inhibit the hydroxylation of warfarin by CYP2C9, thereby limiting enzymatic capacity toward S-warfarin. To test this hypothesis, we investigated the ability of all five racemic hydroxywarfarins to block CYP2C9 activity toward S-warfarin using recombinant enzyme and human liver microsomes. We initially screened for the inhibition of CYP2C9 by hydroxywarfarins using a P450-Glo assay to determine IC(50) values for each hydroxywarfarin. Compared to the substrate, CYP2C9 bound its hydroxywarfarin products with less affinity but retained high affinity for 10- and 4'-hydroxywarfarins, products from CYP3A4 reactions. S-Warfarin steady-state inhibition studies with recombinant CYP2C9 and pooled human liver microsomes confirmed that hydroxywarfarin products from CYP reactions possess the capacity to competitively inhibit CYP2C9 with biologically relevant inhibition constants. Inhibition of CYP2C9 by 7-hydroxywarfarin may be significant given its abundance in human plasma, despite its weak affinity for the enzyme. 10-Hydroxywarfarin, which has been reported as the second most abundant plasma metabolite, was the most potent inhibitor of CYP2C9, displaying approximately 3-fold higher affinity than S-warfarin. These results indicate that hydroxywarfarin metabolites produced by CYP2C9 and other CYPs may limit metabolic capacity toward S-warfarin through competitive inhibition. Subsequent processing of hydroxywarfarins to secondary metabolites, such as hydroxywarfarin glucuronides, could suppress product feedback inhibition, and therefore could play an important role in the modulation of metabolic pathways governing warfarin inactivation and elimination.
Collapse
Affiliation(s)
- Drew R Jones
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA
| | | | | | | | | | | |
Collapse
|
30
|
Jones DR, Moran JH, Miller GP. Warfarin and UDP-glucuronosyltransferases: writing a new chapter of metabolism. Drug Metab Rev 2010; 42:55-61. [PMID: 19788348 DOI: 10.3109/03602530903209395] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The widely prescribed anticoagulant, Coumadin (racemic R/S-warfarin), Bristol-Myers Squibb Company, Clinton, NY has a narrow therapeutic range and wide interindividual response due, in part, to drug metabolism. Early identification of hydroxywarfarins (OHWARs), especially S-7-OHWAR, as major metabolites fostered studies characterizing cytochrome P450s responsible for those reactions. Nevertheless, phase II metabolism by sulfotransferases and, especially uridine diphosphate (UDP)-glucuronosyltransferases (UGTs), marks the next chapter in warfarin inactivation and clearance. Rodents converted OHWARs to glucuronides (O-GLUC), including high levels of 4'-, 7-, and 8-O-GLUC. Similarly, humans generated significant levels of glucuronides following treatment with warfarin. 7-O-GLUC was a major metabolite, while 6- and 8-O-GLUC were minor ones. Surprisingly, warfarin glucuronidation accounted for up to 13% of metabolites. This capacity in humans derives from several UGTs, as shown by studies with recombinant enzymes and racemic warfarin and OHWARs. 7-OHWAR was a high-affinity substrate for UGT1A1, compared to other UGTs. UGT1A1 and UGT1A10 also glucuronidated 6-OHWAR. Of five UGT1A enzymes, UGT1A10 was approximately 7-fold more efficient than the rest. Broad substrate specificity for UGT1A10 derives, in part, from an active site-binding motif, specifically F90-M91-V92-F93. Unlike glucuronidation, less is known about sulfonation of warfarin and its metabolites, except that low capacities are shown by rats and, possibly, humans. Collectively, phase I and II metabolic steps create pathways for inactivating and eliminating warfarin that require elucidation. These findings will ultimately enrich our understanding of warfarin metabolism and facilitate the interpreting of metabolic profiles of patients. This knowledge will possibly avoid complications during warfarin therapy related to metabolism by personalizing therapy for the patient.
Collapse
Affiliation(s)
- Drew R Jones
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA
| | | | | |
Collapse
|
31
|
Miller GP, Jones DR, Sullivan SZ, Mazur A, Owen SN, Mitchell NC, Radominska-Pandya A, Moran JH. Assessing cytochrome P450 and UDP-glucuronosyltransferase contributions to warfarin metabolism in humans. Chem Res Toxicol 2009; 22:1239-45. [PMID: 19408964 DOI: 10.1021/tx900031z] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
As a step toward exploring a targeted metabolomics approach to personalized warfarin (Coumadin) therapy, we developed a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method capable of quantifying specific enantiomeric (R and S) contributions of warfarin (WAR) and the corresponding hydroxywarfarins (OH-WAR) and glucuronides (-GLUC) generated by cytochrome P450s (CYP) and UDP-glucuronosyltransferases (UGTs), respectively. Evaluation of quality control samples and three commercially available human samples showed that our analytical approach has the ability to measure 24 unique WAR metabolites in human urine. Evaluation of the human data also provides new insights for evaluating WAR toxicity and begins characterizing important UGT metabolic pathways responsible for WAR detoxification. Data revealed the significance of specific metabolites among patients and the corresponding enzymatic capacity to generate these compounds, including the first report of direct WAR glucuronidation. On the basis of total OH-WAR levels, (S)-7-OH-WAR was the predominant metabolite indicating the significance of CYP2C9 in WAR metabolism, although other CYP2C enzymes also contributed to clearance of this isomer. (R)-WAR hydroxylation to OH-WARs was more diverse among the patients as reflected in varying contributions of CYP1A2 and multiple CYP2C enzymes. There was wide variation in the glucuronidation of WAR and the OH-WARs with respect to the compounds and patients. 6- and 7-OH-WAR were primarily (>70%) excreted as glucuronides unlike 4'-OH-WAR and 8-OH-WAR. For all patients, UGT1A1 is likely responsible for 6-O-GLUC production, although UGT1A10 may also contribute in one patient. 7-O-GLUC levels reflected contributions from potentially five different UGT1A enzymes. In all cases, WAR, 4'-OH-WAR, 8-OH-WAR, and the corresponding glucuronides were minor metabolites with respect to the others. Taken together, these data suggest that both P450 and UGT reactions contribute to the generation of excretable products in human urine, thereby generating complex metabolic networks.
Collapse
Affiliation(s)
- Grover P Miller
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, 4301 West Markham Street, Little Rock, Arkansas 72205, USA
| | | | | | | | | | | | | | | |
Collapse
|
32
|
Tvrdonova M, Dedik L, Mircioiu C, Miklovicova D, Durisova M. Physiologically motivated time-delay model to account for mechanisms underlying enterohepatic circulation of piroxicam in human beings. Basic Clin Pharmacol Toxicol 2009; 104:35-42. [PMID: 18713233 DOI: 10.1111/j.1742-7843.2008.00304.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The study was conducted to formulate a physiologically motivated time-delay (PM TD) mathematical model for human beings, which incorporates disintegration of a drug formulation, dissolution, discontinuous gastric emptying and enterohepatic circulation (EHC) of a drug. Piroxicam, administered to 24 European, healthy individuals in 20 mg capsules Feldene Pfizer, was used as a model drug. Plasma was analysed for piroxicam by a validated high-performance liquid chromatography method. The PM TD mathematical model was developed using measured plasma piroxicam concentration-time profiles of the individuals and tools of a computationally efficient mathematical analysis and modeling, based on the theory of linear dynamic systems. The constructed model was capable of (i) quantifying different fractions of the piroxicam dose sequentially disposable for absorption and (ii) estimating time delays between time when the piroxicam dose reaches stomach and time when individual of fractions of the piroxicam dose is disposable for absorption. The model verification was performed through a formal proof, based on comparisons of observed and model-predicted plasma piroxicam concentration-time profiles. The model verification showed an adequate model performance and agreement between the compared profiles. Accordingly, it confirmed that the developed model was an appropriate representative of the piroxicam fate in the individuals enrolled. The presented model provides valuable information on factors that control dynamic mechanisms of EHC, that is, information unobtainable with the models proposed for the EHC analysis previously.
Collapse
Affiliation(s)
- Martina Tvrdonova
- Institute of Automation, Measurement and Applied Informatics, Faculty of Mechanical Engineering, Slovak University of Technology, Bratislava, Slovakia
| | | | | | | | | |
Collapse
|
33
|
Ah YM, Kim YM, Kim MJ, Choi YH, Park KH, Son IJ, Kim SG. Drug-induced Hyperbilirubinemia and the Clinical Influencing Factors. Drug Metab Rev 2008; 40:511-37. [DOI: 10.1080/03602530802341133] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|
34
|
Miller GP, Lichti CF, Zielinska AK, Mazur A, Bratton SM, Gallus-Zawada A, Finel M, Moran JH, Radominska-Pandya A. Identification of hydroxywarfarin binding site in human UDP glucuronosyltransferase 1a10: phenylalanine90 is crucial for the glucuronidation of 6- and 7-hydroxywarfarin but not 8-hydroxywarfarin. Drug Metab Dispos 2008; 36:2211-8. [PMID: 18725508 DOI: 10.1124/dmd.108.022863] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Recent studies show that the extrahepatic human UDP-glucuronosyltransferase (UGT)1A10 is capable of phase II glucuronidation of several major cytochrome P450 metabolites of warfarin (i.e., 6-, 7-, and 8-hydroxywarfarin). This study expands on this finding by testing the hypothesis that the UGT1A10 F(90)-M(91)-V(92)-F(93) amino acid motif is important for proper recognition and conjugation of hydroxywarfarin derivatives. Site-directed mutagenesis studies demonstrate that F(90) is critical for 6- and 7-hydroxywarfarin glucuronidation based on the complete loss of enzymatic activity toward these substrates. In contrast, V92A and F93A mutants lead to higher rates of substrate turnover, have minimum changes in K(m) values, and demonstrate substrate inhibition kinetics. A completely different activity profile is observed in the presence of 8-hydroxywarfarin. No change in either activity or affinity is observed with F90A when compared with wild type, whereas F93A and V92A mutants show increases in V(max) (3- and 10-fold, respectively) and minimum changes in K(m). Liquid chromatographytandem mass spectrometry studies show that enzymatic products produced by mutants are identical to wild-type products produced in the presence of 6-, 7-, and 8-hydroxywarfarin. Because F(90) is not critical for the glucuronidation of 8-hydroxywarfarin, there is likely another, different amino acid responsible for binding this compound. In addition, an inhibitory binding site may be formed in the presence of 6- and 7-hydroxywarfarin. This new knowledge and continued characterization of the hydroxywarfarin binding site(s) for UGT1A10 will help elucidate the molecular mechanism of hydroxywarfarin glucuronidation and potentially result in more effective anticoagulant therapies.
Collapse
Affiliation(s)
- Grover P Miller
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | | | | | | | | | | | | | | | | |
Collapse
|