基于雷公藤二萜内酯的代谢规律表征雷公藤毒代动力学生物标志性特征

Tripterygium wilfordii Hook.f.(TWHF) has shown the great treatment effects on various refractory diseases, including immune system disease and inflammatory reaction, etc. However, due to the seriously toxicity and side effects, the clinical applications are still strictly restrained. A research basis for reasonable control of toxicity caused by TWHF can be obtained via its toxicokinetics and biomarker identification that characterizes toxicity.The essential factor for changement of toxicokinetic parameters is drug metablizing enzymes, thus toxicokinetic characteristics of TWHF can be characterized by the specific metabolites produced by its principle toxic components and the metabolism that CYP enzymes involved. On the other hand, diterpene lactones contained in TWHF has the highest activity and strongest toxicity, and is generally accepted as the representative toxic component.Study shows that triptolide(TL), tripdiolide(TD) and triptonide(TN) are the main components of diterpene lactones.In this project, we employ the models of liver microsomal enzymes and recombinant human CYP450 isoforms, combined with evaluation of toxicokinetics in vivo, to perform an in-depth study on the main active and toxic components (TL,TN,TD) with the characteristic spectrum of metabolites and fingerprint spectrum of CYP isoforms involved in metabolism. We also intend to expose the metabolic characteristics and mechanisms of diterpene lactones in TWHF, and then establish a biomarker identification for toxicokinetics characteristic of TWHF, a reliable basis for early warning and monitoring the toxicity of TWHF can thus be provided.

对于免疫系统等难治性疾病，雷公藤显示了良好的治疗效果，由于显著的毒副作用，极大限制了其临床应用。雷公藤的毒代动力学特征以及表征其毒性的生物标志性特征可为临床合理监控雷公藤的毒性提供依据。药物代谢酶是毒代动力学参数改变的最主要原因，雷公藤毒代动力学特征能被其主要毒性成分所产生的特定代谢产物和所参与代谢的CYP代谢酶所表征，雷公藤中二萜内酯类的活性与毒性最强，为雷公藤中公认的代表性有毒成分。其中雷公藤内酯（TL）、雷公藤内酯二醇（TD）、雷公藤内酯酮（TN）为最主要的二萜内酯成分。因此，本课题采用肝微粒体代谢酶模型及重组人源化CYP450亚酶模型，结合体内毒代动力学评价，对雷公藤的关键活性与毒性成分（TL、TN、TD）的代谢物特征谱及参与代谢的CYP亚酶指纹谱进行深入研究，阐明雷公藤二萜内酯类的代谢规律及机理，从而建立表征雷公藤的毒代动力学生物标志性特征，为预警和监控雷公藤的毒性提供依据。

对于免疫系统等难治性疾病，雷公藤显示了良好的治疗效果，由于显著的毒副作用，极大限制了其临床应用。本课题采用肝微粒体代谢酶模型及重组人源化CYP450亚酶模型，结合体内毒代动力学评价，对雷公藤的关键活性与毒性成分（雷公藤内酯醇、雷公藤内酯二醇、雷公藤内酯酮、雷公藤红素）的代谢物特征谱及参与代谢的CYP亚酶指纹谱进行深入研究，阐明雷公藤二萜内酯类的代谢规律及机理，为临床合理监控雷公藤的毒性提供依据。. （1）毒代动力学研究表明：雷公藤的毒性主要来源于二萜内酯类成份，其中雷公藤内酯醇为关键毒性物质；临床上应重点关注。. （2）代谢研究表明雷公藤二萜内酯类成分I相代谢规律以羟化、氧化、开环、脱氢代谢为主，II相代谢途径包括葡萄糖醛酸结合以及硫酸结合；反应性代谢产物主要是谷胱甘肽的结合物；体外孵育体系中雷公藤内酯酮亦可代谢为雷公藤内酯醇和雷公藤内酯二醇。三种雷公藤二萜内酯类成分的体内外研究结果具有高度的相似性，进一步说明其在大鼠和人体中的代谢具有相似性，故在大鼠动物模型中进行雷公藤二萜内酯类成分的毒代动力学研究的结果推断于临床具有一定的可行性。. （3）雷公藤二萜内酯类成分的代谢主要经CYP3A4介导，CYP1A2、CYP2C9、CYP2C19、CYP2E1也有一定的作用。主要通过CYP酶羟化、氧化、开环、脱氢反应，使其极性增大有利于Ⅱ相代谢而被机体清除，完成体内的代谢解毒过程。.（4）阐明CYP酶和外排转运蛋白，尤其是CYP3A4和P-gp，为雷公藤二萜内酯类成分体内解毒关键蛋白。“CYP 酶-外排转运蛋白”清除程序是机体防御和抵抗雷公藤毒性发生的重要机制。二萜内酯类成分的谷胱甘肽反应性代谢产物与肝脏毒性密切相关，为雷公藤产生肝脏损伤的关键毒性物质。. 申请人深入阐述了雷公藤二萜内酯类成分解毒途径，诠释其毒性发生的重要新机制，为有毒中药的毒性研究扩展新思路，提供新的解决方案。