Cycloartane型三萜抗肝损伤构效关系和作用机制的研究

Liver injury is a common pathological basis of many hepatopathy.It is induced mainly by oxidative stress and cytokines mediated apoptosis dysfunction. Based on our previous findings and literature investigations, we found cycloartane triterpenoids are the effective components of many hepatoprotectivemedicinal plants. The current project including the preparation of effective fractions and isolation of no less than 150 (including 15 sub-class) cycloartane triterpenoids, determine their structures and analysis their content. Subsequently,we will evaluate their hepatoprotection activities on cell level and animal level chemical and immunological liver injury models. The Structure-Activity Relationship of cycloartane tritepenoids will be studied by CoMFA method. The manchanism of the cycloartane triterpenoids regulating the key cytokines and proteins of liver injury signal pathway will be investigated by state of the art molecular biology techniques(ELISA/RTPCR/Western blot, etc.). A Liver Injury Associated Protein-Protein Interaction Network (LIAPPIN) will be built to analysis the mechanism from microcosmic machanisms to macroscopic manifestations. Finally, virtual screening and docking will be carried out to investigate the interaction between 3D structures of cycloartane triterpenoids and key proteins. The project will lay a solid foundation for novel drug leads and action mechanism in liver injury.

肝损伤是多种肝脏疾病共有的一种病理基础。我们前期研究发现cycloartane 型三萜通过激活caspase-3、阻断TGFbeta/smad等多种通路发挥良好的保肝作用。本项目拟建立快速分析方法从7 种传统保肝天然药物中分离鉴定不少于150 种该类化合物并完成简单化学修饰转化；然后通过多种细胞、动物水平的肝损伤模型分别评价所有单体、总三萜的药效；进一步通过ELISA、RTPCR 等流行技术揭示其对肝损伤网络中各细胞因子和蛋白表达的调节从而阐明作用机制；在实验基础上利用计算化学、网络生物学理论方法构建可视化肝损伤相关蛋白相互作用网络，cycloartane 类化合物、关键蛋白3D 结构数据库及化合物CoMFA 模型，进而通过生物网络分析、小分子-大分子相互虚拟筛选及对接、3D-QSAR等研究阐明cycloartane 三萜作用靶点、构效关系及其调解肝损伤生物网络的关键节点和整体药效的实现。

损伤是多种肝脏疾病共有的一种病理基础。我们前期研究发现cycloartane 型三萜具有保肝作用。本项目对富含cycloartane三萜的黄芪Astragalus membranaceus；升麻 Cimicifuga foetida；铁破锣Beesia calthaefolia；黄三七 Souliea vaginata；栀子Gardenia jasminoides；米仔兰Aglaia odorata；鹧鸪麻Kleinhovia hospita等植物进行了详细研究。从这些植物中，分离得到化合物100个以上，其中cycloartane型三萜类化合物70种左右，发现结构新颖的cycloartane型三萜类化合物27个，并发现其他新骨架化合物3个。建立了关键化合物在药材中的含量测定方法，完成了总三萜含量测定和同时测定多种三萜单体化合物的含量。发现并初步阐明了十余个结构子类型与保肝活性、肝毒性之间的构效关系。通过本项目的实施，基本上明确了cycloartane型三萜结构子类型在分类学、构效关系、构毒关系中的重要价值；极大地丰富了cycloartane型三萜的结构多样性；明确了具有开发为抗肝损伤药物前景的先导化合物。