人尿苷二磷酸葡糖醛酸转移酶参与马钱子碱和士的宁体外代谢研究

Identification of UDP-glucuronosyltransferase Isoforms Responsible for Strychnine and Brucine Metabolism in Vitro

目的考察参与士的宁和马钱子碱Ⅱ相代谢的主要人尿苷二磷酸葡糖醛酸转移酶(UGTs)亚型,为预测其与其他药物代谢性相互作用提供理论借鉴。方法士的宁和马钱子碱分别与大鼠肝微粒体(RLMs)、人肝微粒体(HLMs)和12种主要人重组UGTs亚酶进行孵育,采用高效液相色谱-串联质谱(HPLC-MS/MS)法检测士的宁和马钱子碱葡糖醛酸代谢产物,考察参与其体外Ⅱ相代谢UGTs亚酶类型。结果马钱子碱和士的宁均在HLMs里生成1个单葡糖醛酸代谢产物,而在RLMs中未产生,单酶试验中二者均只在UGT1A4重组酶中发生代谢。结论马钱子碱和士的宁在人鼠代谢中存在种属差异,UGT1A4为其主要代谢亚酶。该研究结果可为临床预防马钱子因药物代谢性相互作用引发的不良反应提供理论和实验依据。

Objective To investigate the role of phase Ⅱ enzyme UDP-glucuronosyl transferases(UGTs)in strychnine and brucine metabolism,and to predit the mechanism of metabolic drug-drug interactions of strychnine and brucine with other drugs. Methods Strychnine and brucine were incubated with rat liver microsomes(RLMs),human liver microsomes (HLMs) and 12 human recombinant UGTs subtype supersome,respectively. The glucuronide metabolites of strychnine and brucine were detected by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Results Single metabolite glucuronidation of strychnine and brucine was occurred in HLMs,but not in RLMs. The human recombinant UGTs supersomes results showed that UGT1A4 was the dominant subtype mediating the glucuronidation of strychnine and brucine. Conclusion There is species difference between human being and rats. UGT1A4 was a major subtype mediating strychnine and brucine glucuronidation. This research sets a basis for the prevention of ADRs caused by drugdrug interactions between Semen Strychni and other drugs.