太白银莲花皂苷的分离鉴定和基于原位给药途径的抗胶质瘤活性研究

The unclear mechanisms and structure-activity relationships (SAR), and the haemolytic side effects are three puzzles in the development of antitumor saponins as new drugs. Many saponins for the treatment of glioblastoma were not capable of crossing the blood-brain barrier. However, the approach of interstitial chemotherapy of glioblastoma, an in situ administration route, can overcome this obstacle. The applicant assumed applying this administration route to saponins which showed potent anti-tumor activities in vitro to treat neuroglioma. The administration route may happen to avoid the common haemolytic effects and the side effects of saponins by iv administration. Based on this applying outlook of antitumor saponins, the studies of SAR will be more targeted. The feasibility of the hypothesis was verified by our previous work, however, further studies are needed to confirm them..We have found 10 new triterpeniod saponins from the rhizomes of Anemone taipaiensis, which showed anti-glioblastoma activities by inducing apoptosis of tumor cells. However, their structural diversity has not been elucidated completely, and this led to the incompleteness in the studies on the activities in vivo and in vitro and the mechanisms of them. This hindered us to obtain their definite structure-function relationship..Based on the above studies, we will carry out further isolation and structure elucidation of the saponins from A. taipaiensis to obtain sufficient samples, evaluate their anti-glioblastoma activities and mechanisms of inducing apoptosis systematically, study their activities, toxicities and mechanisms in vivo through interstitial chemotherapy of glioblastoma by in situ, and finally obtain the definite structure-activity relationship of these triterpenoid saponins..The results of this study will offer valuable data and give an example for the resolve of the three problems in the development of saponins, and establish a homebase in the search of novel, safe and efficient lead compounds for the treatment of glioblastoma.

作用机制不清、构效关系不明、溶血副作用是限制抗肿瘤皂苷成药性与其新药研发的三大难题。皂苷的胶质瘤化疗常存在血脑屏障，间质化疗的原位给药途径可克服此障碍。申请者设想将有抗肿瘤活性的皂苷采用间质化疗途径用于抗胶质瘤治疗，又恰可规避因其溶血性和注射副反应而无法注射给药的难题。在此基础上研究皂苷构效关系更具针对性。前期研究初步证实该设想的可行性，但尚需深入验证。.申请者从太白银莲花中发现了10个可能主要基于诱导凋亡机制抗胶质瘤的、结构新颖的三萜皂苷，但其结构多样性尚未完全阐明，使得体内外活性和作用机制研究不完善，无法得到明确的构效关系结论。.本项目拟进一步分离鉴定其皂苷成分，得到更多及足量样品；系统评价皂苷抑瘤活性和诱导凋亡机制；并通过间质化疗途径研究其体内活性、毒性和作用机制；获得确切的构效关系结论。.该研究将可为解决皂苷开发的三大难题提供资料和借鉴，为发掘新型胶质瘤化疗先导化合物提供依据。

作用机制不清、构效关系不明、溶血副作用是限制抗肿瘤皂苷成药性与其新药研发的三大难题。皂苷的胶质瘤化疗常存在血脑屏障，间质化疗的原位给药途径可克服此障碍。项目组设想将有抗肿瘤活性的皂苷采用间质化疗途径用于抗胶质瘤治疗，又恰可规避因其溶血性和注射副反应而无法注射给药的难题，故选取太白银莲花为研究对象，以其所含齐墩果烷型皂苷的抗胶质瘤作用机制和构效关系研究为突破口，开展了系统研究。. 在前期工作的基础上，从太白银莲花的根茎和地上部分新分离鉴定皂苷54个，其中新化合物16个，并通过化学方法得到5个次级苷和3个苷元；完成了药理活性测试，获得10余种具有抑制胶质瘤增殖活性的成分；完成了6种具有结构代表性的活性皂苷诱导胶质瘤细胞凋亡的作用机制研究，初步明确了它们抗胶质瘤的分子机制；分析了这些皂苷抗胶质瘤活性的构效关系；研究了2种皂苷在荷瘤裸鼠模型和原位接种模型（间质化疗途径）对胶质瘤生长的影响和毒副作用，特别是制备了1种皂苷的缓释制剂，验证了皂苷采用间质化疗途径用于抗胶质瘤治疗以规避溶血性的可行性。. 对同属植物大火草、小花草玉梅、打破碗花花、反萼银莲花以及粗齿铁线莲、毛蕊铁线莲、大叶铁线莲和宽叶重楼、金线重楼的皂苷成分进行了系统研究，鉴定了158个皂苷，其中新化合物43个，发现了20余种具有抑制胶质瘤增殖活性的成分，并对活性最强的皂苷开展了初步的抗胶质瘤作用机制研究。. 本项目已发表期刊论文14篇，其中SCI收录论文12篇；在学术会议交流24篇，其中6篇论文获奖；获国家发明专利授权4项、申请1项；部分成果作为支撑内容之一获省科技一等奖1项；培养研究生11人。研究成果为解决限制抗肿瘤皂苷成药性与其新药研发的三大难题提供了有价值的资料和借鉴，通过对间质化疗途径的探讨和验证，为具有溶血作用或注射毒副反应的皂苷类成分的开发提供一种新的选择，对于皂苷类新药的开发具有重要的理论指导意义和实践价值。