雷公藤甲素在人和大鼠肝微粒体代谢消除和酶动力学的比较研究  

Comparative study of metabolic clearance and enzymatic kinetics of triptolide in human and rat liver microsomes

作　　者：吴桐 阳海鹰 原梅 车津晶 李桦 WU Tong;YANG Hai-ying;YUAN Mei;CHE Jin-jing;LI Hua(Institute of Pharmacology and Toxicology,Academy of Military Medical Sciences,Beijing 100850,China)

机构地区：[1]军事医学研究院毒物药物研究所,抗毒药物和毒理学国家重点实验室,北京100850

出　　处：《中国药理学通报》2018年第10期1414-1419,共6页Chinese Pharmacological Bulletin

基　　金：国家科技部“重大新药创制”科技重大专项(No2008ZXJ09006001,2015ZX09J15104)

摘　　要：目的研究中药活性成分雷公藤甲素(triptolide,TP)在人和大鼠肝微粒体的代谢消除性质和酶促动力学特征,比较种属间差异,为深入研究代谢与肝毒性的关系提供科学依据。方法应用前期验证的LC-MS/MS方法,定量检测孵育体系中的雷公藤甲素,考察其在人和大鼠肝微粒体的代谢稳定性和酶促动力学;研究雷公藤甲素在人源重组CYP3A4、大鼠源重组CYP3A1和3A2同工酶孵育体系中的酶促动力学,计算并比较酶动力学参数。结果雷公藤甲素在人肝微粒体的代谢消除明显慢于大鼠,消除半衰期T^(1/2)分别为(154±9.4)、(19.9±0.09)min(P<0.01)。雷公藤甲素在人和大鼠肝微粒体的表观酶动力学参数K_m分别为(11.2±3.45)、(18.4±3.29)μmol·L^(-1),V_(max)分别为(139±12.6)、(2194±176.7)pmol·min^(-1)·mg^(-1);在CYP3A4、3A1、3A2的K_m分别为(15.5±1.80)、(5.89±0.96)、(9.55±3.13)μmol·L^(-1),V_(max)分别为(11.1±0.91)、(62.8±16.17)、(51.6±10.19)pmol·min^(-1)·pmol^(-1),差异具有显著性。结论雷公藤甲素的肝微粒体代谢消除和酶促动力学存在明显的种属差异,其与人和大鼠CYP3A亚型的亲和力和反应速率差异是代谢消除种属差异的原因之一。To investigate the species differences of triptolide(TP)metabolism in human and rat liver microsomes,by comparing the metabolic clearance and enzymatic kinetics,and to provide scientific bases for further study of the association between TP metabolism and hepatotoxicity.Methods The concentrations of triptolide were measured using a previously validated LC-MS/MS method.The metabolic stability and enzymatic kinetics of TP were determined in liver microsomes incubates with NADPH.The enzymatic kinetics in human recombinant CYP3A4 and rat recombinant 3A1,3A2 incubates were also determined to explore the possible causes for observation of species differences in liver microsomes.Results The metabolic elimination of TP in human liver microsomes was significantly lower than that in rat liver microsomes,with the T 1[]2 values of(154.4±9.35)and(19.93±0.09)min in human and ratrespectively(P<0.01).The K m and V max of TP in human and rat liver microsomes were(11.23±3.45)and(18.38±3.29)μmol·L-1,(138.8±12.62)and(2194±176.7)pmol·min-1·mg-1,respectively.The K m and V max of triptolide in Supersomes CYP3A4,3A1 and 3A2 were(15.46±1.8),(5.89±0.96)and(9.55±3.13)μmol·L-1,(11.05±0.91),(62.77±16.17)and(51.58±10.19)pmol·min-1·pmol-1,respectively.The kinetic parameters were significantly different between the two species.Conclusion The significant species differences are observed in metabolic clearance and enzymatic kinetics of TP,which is partially attributable to the differences in affinity and reaction rate between human and rat CYP3A isoforms.

关 键 词：雷公藤甲素 肝微粒体 细胞色素P4503A酶 代谢消除 酶动力学 种属差异 

分 类 号：R-332[医药卫生] R284.1