黄皮中咔唑生物碱的抗肿瘤作用机制与构效关系研究

Clausena lansium is a plant belongs to family Rutaceae and mainly distributed in southern provinces, such as Yunnan, Guizhou and Guangxi provinces. Its roots, leaves and fruit cores could be used for improving digestion, promoting metabolism, relieving pain and expectorant. Its chemical components mainly include coumarins, carbazole alkaloids and amide alkaloids, and their biological activities involve into antimicrobial, antitumor, antimalarial, liver protection, antiplatelet aggregation, reducing blood lipid and so on. In the previous studies, 30 carbazole alkaloids were isolated from stems and roots of C. lansium and most of them showed strong cytotoxic activities. Especially, the IC50 values of Clausine D on HeLa and BGC-823 tumor cell lines were 0.37 μM and 0.99 μM, equivalent to Taxol. Here, in the current project we aim to: 1) isolate and identify carbazole alkaloids from the branches and leaves of C. lansium, which will provide material base for the next study of structure-activity relationships; 2) study the mechanism of action of Clausine D with tumor cell line, which will discover the mainly target protein and provide pharmacological information for research and development of anticancer drug of carbazole alkaloids; 3) study the structure-activity relationships of these carbazole alkaloids with anti-tumor activities, which will provide theoretical basis for design and development lead compound of carbazole alkaloids with stronger anti-tumor activities.

黄皮为芸香科黄皮属植物，国内主要分布于云南、贵州和广西等南方省份。其根、叶和果核具有行气、消滞、解表、止痛和化痰等功效；所含化学成分类型主要包括香豆素、咔唑生物碱和酰胺，其活性包括抗菌、抗肿瘤、抗疟、保肝、抗血小板凝聚及降血脂等。项目申请者前期从黄皮的根和茎中分离得到30个咔唑生物碱，并发现该类分子普遍具有较强的细胞毒活性，其中Clausine D对Hela和BGC-823两个肿瘤细胞株的IC50值分别为0.37 μM和0.99 μM，活性同紫杉醇相当。在此基础上，本项目拟：1）对黄皮枝叶部分的咔唑生物碱进行系统的分离和鉴定，为后续的构效分析提供更丰富的物质基础；2）对Clausine D的抗肿瘤作用机制进行研究，明确其主要作用靶蛋白，为该类分子的抗肿瘤药物研发提供药理学信息；3）对所得咔唑生物碱的构效关系进行研究，为设计和开发活性更强的咔唑生物碱类抗肿瘤先导化合物提供依据。

芸香科黄皮属植物富含咔唑生物碱、香豆素和酰胺类生物碱，其中咔唑生物碱类化合物具有良好的细胞毒活性。为明确该类分子的抗肿瘤作用机制及抗肿瘤活性的关键靶蛋白，本项目在前期研究的基础之上，对具有较强细胞毒活性的化合物Clausine D开展9种肿瘤细胞株的细胞毒活性评价。研究发现该化合物对人胃癌细胞株SGC-7901不但活性好，而且呈现出线性的量效关系。随后开展该化合物对SGC-7901细胞株的细胞周期和细胞凋亡、以及细胞凋亡和周期阻滞相关蛋白表达的影响的研究，结果表明该化合物能够诱导胃癌SGC-7901细胞发生细胞凋亡，并引起G2/M期细胞周期阻滞，其作用与抑制ERK1/2和JNK信号通路的激活有关，进一步的研究发现该分子能够抑制微管蛋白聚合。同时，本项目对黄皮中分离到的咔唑生物碱的细胞毒活性进行构效关系分析，明确了该类分子各官能团电性因素及立体空间因素对细胞毒活性的影响，为咔唑生物碱类分子结构修饰和抗肿瘤药物开发提供理论依据。