基于类法尼醇X受体调控的藏药裸茎金腰逆转肝内胆汁淤积的药效物质及其构效关系和作用机制研究

Cholestasis is a clinical syndrome of liver damage that is caused by accumulationof bile acids in the liver and systemic circulation. It would lead to hepatic failure due to long-term cholestasis. To date, drugs for the treatment of IC are very limited and have serious adverse effects. Thus, it is of great significance to find new drugs for the treatment of IC. Farnesoid X receptor (FXRα) can regulate synthesis, metabolism, and excretion of bile acids, which indicates that it is a new trend to screen selective agonists of FXRα for the therapy of IC. Our previous study found that the extract of specialist Tibetan medicine Chrysosplenium nudicaule (YAJIMA) displayed significant reversing effect against cholestasis induced by ANIT in rat through regulation of FXRα. Therefore, we are planning to carry out these studies as follows. The metabolic fingerprint of the migrating components of the extract in rats is to be established to guided-isolation of the active components with agonist activity for FXRα. A pharmacophore model of active components was established by the method of computational chemistry. Furthermore, based on the cell pharmacological model, the underlying mechanism by which active components to reverse the IC based on FXRα signaling pathway was investigated by a variety of modern molecular biology techniques. We hope to clarify the functional basis of C. nudicaule and guide its clinical use and new drug development. This study will elucidate the pharmacological substances responsible for the activity of reversing IC by the specialist Tibetan medicine C. nudicaule. The results will provide theoretical support for its clinical use and further development of new drugs based on C. nudicaule and its chemical components.

肝内胆汁淤积（IC）是一种由于胆汁酸在肝内蓄积从而引发肝脏病变的临床综合征，长期IC可致肝衰竭。目前治疗IC的药物十分有限，且存在严重不良反应。因此，寻找治疗IC的新型药物有重要意义。类法尼醇X受体（FXRα）可调控胆汁酸合成、代谢和转运，其选择性激动剂成为IC治疗药物研究的新趋势。特色藏药裸茎金腰(亚吉玛)是藏医临床治疗肝胆疾病的良药。前期研究发现，其提取物可通过调节FXRα，逆转ANIT诱导的大鼠IC。因此，本研究拟：建立该提取物在大鼠体内移行成分的代谢指纹图谱，指导其FXRα激动活性成分的定向分离；采用离体筛选模型评价活性成分的选择性FXRα激动活性；采用计算化学法建立活性成分的药效团模型；进而基于细胞药理模型，采用现代分子生物学技术，深入探讨活性成分基于FXRα信号通路逆转IC的作用机制。本研究将阐明特色藏药裸茎金腰逆转IC的药效物质基础，为其临床使用与进一步新药开发提供理论支撑。

肝内胆汁淤积（IC）是一种由于胆汁酸在肝内蓄积从而引发肝脏病变的临床综合征，长期IC可导致肝衰竭。目前治疗IC的药物十分有限，且存在严重不良反应。因此，寻找治疗IC的新型药物具有重要意义。藏药典籍记载，亚吉玛具有清热利胆，缓泻下的功效，临床用于胆热证，发烧，头痛，胆囊炎，胆结石等。亚吉玛为多基源藏药，文献和相关药材标准关于其基源的表述大多为“裸茎金腰及其同属数种”。这种笼统的表述给该药材的规范使用和质量监管造成了极大的不便。此外，亚吉玛对肝胆类疾病的现代药效学评价仍未见报道，其药效物质基础和作用机制仍不清楚。针对这些状况，课题组首先对亚吉玛进行了系统的品种整理，包括深入的文献考证和基源物种资源调查、药材市场流通情况调查、药材使用现状调查以及药材的化学和药理研究。在此基础上，明确了亚吉玛的主流基源为长梗金腰和肉质金腰，其中长梗金腰药用价值远强于肉质金腰。进而对长梗金腰开展了系列工作：1）长梗金腰抗IC性肝损伤药效部位筛选，获得其有效部位为乙酸乙酯部位和正丁醇部位；2）对长梗金腰有效部位抗IC型肝损伤的药效物质基础进行了研究，从中鉴定了22个入血移行成分，并采用细胞模型评价了抗肝损伤活性。结果表明，包括量丰成分CA1和CA2在内的11个化合物具有不同程度的保肝活性。3) 基于动物模型评价了CA1和CA2的抗IC型肝损伤药效并进行作用机制探讨。结果表明，CA1及CA2通过激活FXR受体信号通路和NF-κB炎症信号通路来发挥逆转ANIT致小鼠IC型肝损伤的作用；4）活性单体CA1的药代动力学、排泄规律及体内代谢产物研究；5）初步制定亚吉玛（长梗金腰）的药材质量标准。本研究成果为亚吉玛/长梗金腰药材的质量监管及临床使用提供了参考，同时也为以CA1/CA2为先导化合物的抗肝内胆汁淤积型新型药物开发提供理论支撑。