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Published on: April 22, 2022
N-glucuronidation catalyzed by UGT1A4 and UGT2B10 in human liver microsomes: Assay optimization and substrate
Danyi Lu1, Qian Xie2, Baojian Wu2
1Research Center for Biopharmaceutics and Pharmacokinetics, College of Pharmacy, Jinan University, Guangzhou, China; Shenzhen Key Laboratory for Molecular Biology of Neural Development, Guangdong Key Laboratory of Nanomedicine, Institute of Biomedicine and Biotechnology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China; Guangdong Province Key Laboratory of Pharmacodynamic Constituents of TCM and New Drugs Research, Jinan University, Guangzhou, China.
Abstract:
N-glucuronidation is an important pathway for metabolism and disposition of tertiary amines in humans. This reaction is mainly catalyzed by the enzymes UGT1A4 and UGT2B10. However, the metabolic patterns of UGT1A4- and UGT2B10-mediated N-glucuronidation are not fully clear. In this study, we first optimized in vitro reaction conditions for N-glucuronidation by using specific substrates (i.e., trifluoperazine for UGT1A4, cotinine and amitriptyline for UGT2B10). Furthermore, we found that hepatic N-glucuronidation showed significant species differences. In addition, UGT1A4 and UGT2B10 were primarily responsible for N-glucuronidation of many tertiary amines, including asenapine, loxapine, clozapine, chlorpromazine, dothiepin, doxepin, mirtazapine, mianserin, chlorcyclizine, cyclizine, promethazine, cyclobenzaprine, imatinib, retrorsine, strychnine and brucine. In conclusion, this study provides an in vitro assay system for evaluating N-glucuronidation of amines. Also, UGT1A4- and UGT2B10-mediated N-glucuronidation might play significant roles in metabolism and detoxification of tertiary amines in humans.
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