基于核受体FXR相关胆汁酸代谢及炎症通路的藏药“松蒂”类药材抗胆汁淤积活性物质及作用机制研究

Cholestasis is one of the common symptoms of various liver diseases, and its clinical drugs are scarce and lack efficacy. "Songdi" is a kind of common medicine treating liver and gallbladder diseases in Tibetan medicine, but its active substances and mechanisms are not well known. In the previous research，48 components including 15 new ingredients were obtained from Saxifraga umbellulata var. pectinata(SU), one major variety of "Songdi". And the preliminary activity studies showed that its extract could significantly alleviate acute intrahepatic cholestasis liver injury induced by ANIT and acute liver injury induced by CCl4 in mice. It was also found that its total extract, effective fractions and several monomers could not only significantly protect L-02 cells from CCl4 damage, but also could upregulate BSEP and MRP3, two export transporters in HepG2 cells. The composition comparison analysis showed that there were "similar components" between the other several mixed varieties and SU. We speculated that the mechanisms of "Songdi" against cholestasis and related inflammation may be relevant to the pathways of bile acid metabolism and inflammation associated with farnesoid X receptor, and the similar components mentioned above may be active ingredients. The project proposed here intends to continually explore the active substances of anti-cholestasis from "Songdi" resouces and to deeply analyze the regulation mechanisms, so as to lay a foundation for the development of new resources for "Sondi" medicinal materials and the new anti-cholestasis drugs with special characteristics of Tibetan medicine.

胆汁淤积是多种肝病的共同症状之一，其临床治疗药物匮乏且疗效有限。“松蒂”是藏医优势病种-肝胆类疾病的常用药物，但其活性物质及作用机制不明。申请人前期从“松蒂”主流品种篦齿虎耳草中分离出48个成分（15个新成分）；初步活性研究表明其提取物对ANIT致小鼠急性肝内胆汁淤积性肝损伤和CCl4致小鼠急性肝损伤均具有显著保护作用；并发现总提物、有效部位及数个有效成分能显著抵抗CCl4致L-02细胞损伤，且能显著提高HepG2细胞中胆汁酸转运体BSEP和MRP3的表达；成分比较结果表明“松蒂”其他数个混用品种与篦齿虎耳草存在“共性成分”。我们推测“松蒂”抗胆汁淤积及相关炎症的机制与核受体FXR介导的胆汁酸代谢通路与炎症通路有关，且前述“共性成分”也很可能就是有效成分。故本项目拟继续从“松蒂”类药材中发掘抗胆汁淤积活性物资，深入解析其作用机制，为开发“松蒂”类药材新资源及抗胆汁淤积特色藏药新药奠定基础。

“松蒂”是一种通常用于治疗肝胆疾病的传统藏药，来源于当地多种虎耳草属植物，前期研究表明这些虎耳草属植物品种间在化学成分组成上既有相似性，也极具差异性。小伞虎耳草（SU）是“松蒂”类药材的的主流品种，前期研究主要集中在其化学基础研究上，初步研究表明其具有抗胆汁淤积性肝炎的活性。我们在前期研究基础上，结合现代化学、分析、药理学、代谢组学和其他多学科方法和技术，基本完成了本项目计划中的主要研究任务和目标。由于藏医就地用药的传统，唐古特虎耳草（ST）在青海藏区被当作SU的替代品作为“松蒂”使用。为调查这种替代背后的合理性，我们采用HPLC指纹图谱对这两种物种之间的化学相似性和差异性进行了系统分析，并分离鉴定了它们中可作为质量标志物的化学成分用以区分这两个物种，提升了“松蒂”类相关药材的质量控制标准。我们采用动物实验揭示了SU提取物抗胆汁淤积的作用机制-涉及到激活FXR相关信号通路和调节体内胆汁酸代谢。此外，我们通过体外细胞实验发现SU中的数种活性成分可以激活细胞中FXR相关信号通路中的不同蛋白受体，这些活性成分正是“松蒂”类药材中的标志性成分，即具有葫芦烷型三萜类、齐墩果烷型三萜类、或二苯壬烷类结构的成分。综上，我们解析出了一个多成分-多靶点作用于FXR相关信号通路的协作网络来解释“松蒂”类药材抗胆汁淤积的活性物质及其作用机制。