College of Pharmacy, Jinan University, Guangzhou 510632, China.
Guangdong Provincial Key Laboratory of Pharmacodynamic Constituents of TCM and New Drugs Research, College of Pharmacy, Jinan University, Guangzhou 510632, China.
Int J Mol Sci. 2017 Sep 19;18(9):1983. doi: 10.3390/ijms18091983.
Wushanicaritin, a natural polyphenol compound, exerts many biological activities. This study aimed to characterize wushanicaritin glucuronidation by pooled human liver microsomes (HLM), human intestine microsomes and individual uridine diphosphate-glucuronosyltransferase (UGT) enzyme. Glucuronidation rates were determined by incubating wushanicaritin with uridine diphosphoglucuronic acid-supplemented microsomes. Kinetic parameters were derived by appropriate model fitting. Reaction phenotyping, the relative activity factor (RAF) and activity correlation analysis were performed to identify the main UGT isoforms. Wushanicaritin glucuronidation in HLM was efficient with a high (intrinsic clearance) value of 1.25 and 0.69 mL/min/mg for G1 and G2, respectively. UGT1A1 and 1A7 showed the highest activities with the intrinsic clearance () values of 1.16 and 0.38 mL/min/mg for G1 and G2, respectively. In addition, G1 was significantly correlated with β-estradiol glucuronidation ( = 0.847; = 0.0005), while G2 was also correlated with chenodeoxycholic acid glucuronidation ( = 0.638, = 0.026) in a bank of individual HLMs ( = 12). Based on the RAF approach, UGT1A1 contributed 51.2% for G1, and UGT1A3 contributed 26.0% for G2 in HLM. Moreover, glucuronidation of wushanicaritin by liver microsomes showed marked species difference. Taken together, UGT1A1, 1A3, 1A7, 1A8, 1A9 and 2B7 were identified as the main UGT contributors responsible for wushanicaritin glucuronidation.
巫山淫羊藿素是一种天然多酚化合物，具有多种生物学活性。本研究旨在利用人肝微粒体（HLM）、人肠微粒体和个体尿苷二磷酸葡萄糖醛酸转移酶（UGT）酶对巫山淫羊藿素的葡萄糖醛酸化作用进行特征描述。通过用尿苷二磷酸葡萄糖醛酸补充的微粒体孵育巫山淫羊藿素来测定葡萄糖醛酸化速率。通过适当的模型拟合得出动力学参数。进行反应表型鉴定、相对活性因子（RAF）和活性相关分析，以确定主要的 UGT 同工酶。巫山淫羊藿素在 HLM 中的葡萄糖醛酸化效率很高，G1 和 G2 的内在清除率（）值分别为 1.25 和 0.69 mL/min/mg。UGT1A1 和 1A7 表现出最高的活性，G1 和 G2 的内在清除率（）值分别为 1.16 和 0.38 mL/min/mg。此外，G1 与 β-雌二醇葡萄糖醛酸化显著相关（ = 0.847； = 0.0005），而 G2 与鹅去氧胆酸葡萄糖醛酸化也相关（ = 0.638， = 0.026），在一个个体 HLM 库中（ = 12）。基于 RAF 方法，UGT1A1 对 G1 的贡献为 51.2%，UGT1A3 对 G2 的贡献为 26.0%。此外，肝微粒体对巫山淫羊藿素的葡萄糖醛酸化作用表现出明显的种属差异。综上所述，UGT1A1、1A3、1A7、1A8、1A9 和 2B7 被鉴定为负责巫山淫羊藿素葡萄糖醛酸化的主要 UGT 贡献者。
