title: Glucuronidation of edaravone by human liver and kidney microsomes: biphasic kinetics and identification of UGT1A9 as the major UDP-glucuronosyltransferase isoform.
abstract: Edaravone was launched in Japan in 2001 and was the first neuroprotectant developed for the treatment of acute cerebral infarction. Edaravone is mainly eliminated as glucuronide conjugate in human urine (approximately 70%), but the mechanism involved in the elimination pathway remains unidentified. We investigated the glucuronidation of edaravone in human liver microsomes (HLM) and human kidney microsomes (HKM) and identified the major hepatic and renal UDP-glucuronosyltransferases (UGTs) involved. As we observed, edaravone glucuronidation in HLM and HKM exhibited biphasic kinetics. The intrinsic clearance of glucuronidation at high-affinity phase (CL(int1)) and low-affinity phase (CL(int2)) were 8.4 ± 3.3 and 1.3 ± 0.2 μl · min(-1) · mg(-1), respectively, for HLM and were 45.3 ± 8.2 and 1.8 ± 0.1 μl · min(-1) · mg(-1), respectively, for HKM. However, in microsomal incubations contained with 2% bovine serum albumin, CL(int1) and CL(int2) were 16.4 ± 1.2 and 3.7 ± 0.3 μl · min(-1) · mg(-1), respectively, for HLM and were 78.5 ± 3.9 and 3.6 ± 0.5 μl · min(-1) · mg(-1), respectively, for HKM. Screening with 12 recombinant UGTs indicated that eight UGTs (UGT1A1, UGT1A6, UGT1A7, UGT1A8, UGT1A9, UGT1A10, UGT2B7, and UGT2B17) produced a significant amount of glucuronide metabolite. Thus, six UGTs (UGT1A1, UGT1A6, UGT1A7, UGT1A9, UGT2B7, and UGT2B17) expressed in human liver or kidney were selected for kinetic studies. Among them, UGT1A9 exhibited the highest activity (CL(int1) = 42.4 ± 9.5 μl · min(-1) · mg(-1)), followed by UGT2B17 (CL(int) = 3.3 ± 0.4 μl · min(-1) · mg(-1)) and UGT1A7 (CL(int) = 1.7 ± 0.2 μl · min(-1) · mg(-1)). Inhibition study found that inhibitor of UGT1A9 (propofol) attenuated edaravone glucuronidation in HLM and HKM. In addition, edaravone glucuronidation in a panel of seven HLM was significantly correlated (r = 0.9340, p = 0.0021) with propofol glucuronidation. Results indicated that UGT1A9 was the main UGT isoform involved in edaravone glucuronidation in HLM and HKM.
authors.affiliation: Key Laboratory of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University, 24 Tong Jia Xiang, Nanjing, Jiangsu, 210009, China.
authors.forename: Liping
authors.initials: L
authors.lastname: Ma
authors.forename: Jianguo
authors.initials: J
authors.lastname: Sun
authors.forename: Ying
authors.initials: Y
authors.lastname: Peng
authors.forename: Rong
authors.initials: R
authors.lastname: Zhang
authors.forename: Feng
authors.initials: F
authors.lastname: Shao
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Hu
authors.forename: Jianping
authors.initials: J
authors.lastname: Zhu
authors.forename: Xiaojin
authors.initials: X
authors.lastname: Wang
authors.forename: Xuefang
authors.initials: X
authors.lastname: Cheng
authors.forename: Yinci
authors.initials: Y
authors.lastname: Zhu
authors.forename: Ping
authors.initials: P
authors.lastname: Wan
authors.forename: Dong
authors.initials: D
authors.lastname: Feng
authors.forename: Hui
authors.initials: H
authors.lastname: Wu
authors.forename: Guangji
authors.initials: G
authors.lastname: Wang
mesh_terms: D000738:Androsterone / Q000494:pharmacology; D000983:Antipyrine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism / Q000493:pharmacokinetics; D002851:Chromatography, High Pressure Liquid; D004305:Dose-Response Relationship, Drug; D000077553:Edaravone; D004958:Estradiol / Q000494:pharmacology; D020719:Glucuronides / Q000378:metabolism*; D014453:Glucuronosyltransferase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007527:Isoenzymes; D007668:Kidney / Q000201:enzymology / Q000378:metabolism*; D007700:Kinetics; D008657:Metabolic Clearance Rate; D008861:Microsomes / Q000201:enzymology / Q000378:metabolism; D008862:Microsomes, Liver / Q000201:enzymology / Q000378:metabolism*; D015394:Molecular Structure; D009270:Naloxone / Q000494:pharmacology; D015742:Propofol / Q000494:pharmacology; D053719:Tandem Mass Spectrometry; D000090264:UDP-Glucuronosyltransferase 1A9
chemical_list: D020719:Glucuronides; D007527:Isoenzymes; C000715591:UGT1A9 protein, human; D009270:Naloxone; D004958:Estradiol; D000738:Androsterone; D014453:Glucuronosyltransferase; D000090264:UDP-Glucuronosyltransferase 1A9; D000077553:Edaravone; D000983:Antipyrine; D015742:Propofol