通过间质化疗途径抗胶质瘤的海星甾体皂苷类成分的制备、体内外活性和作用机制研究

The antitumor activities of saponins have attractted extensive attention. However, the unclear mechanisms and structure-activity relationships, and the haemolytic side effects are three puzzles in the development of saponins as new drugs. The applicant assumed applying the approach of interstitial chemotherapy, an in situ administration route, to saponins which showed potent anti-tumor activities in vitro to treat neuroglioma. The administration route can overcome the obstacle of saponins not capable of crossing the blood-brain barrier, and happen to avoid the common haemolytic effects and the side effects of saponins by iv administration. The feasibility of the hypothesis was verified by our previous work, however, further studies are needed to confirm them. The research and development of steroidal saponins from starfishes face the same puzzles, and this make their application future in doubt. We have found 12 new steroidal saponins from three species of starfishes, which showed anti-glioblastoma activities by inducing apoptosis of tumor cells. However, their structural diversity and the definite signal pathway of their effects have not been elucidated completely, and this hindered us to obtain their clear structure-function relationship. And the studies on the anti-glioblastoma activities in vivo were also imperfect. Based on the above studies, we will carry out further isolation, structural elucidation and modification of the steroidal saponins from the starfishes Culcita novaeguineae and Anthenea chinensis to obtain sufficient samples, analyze their definite structure-activity relationship, clarify their mechanisms of inducing apoptosis systematically. The substained release preparation of the steroidal saponins will be prepared and their activities, toxicities and mechanisms in vivo through interstitial chemotherapy of glioblastoma by in situ will be studied. The results of this study will offer valuable data and give an example for the solution of the three problems in the development of saponins, and provide a basis for the application future of steroidal saponins from starfishes.

皂苷的抗肿瘤作用备受关注，作用机制不清、构效关系不明、溶血副作用是限制其成药性的三大难题。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，以克服其难突破血脑屏障的障碍，又规避因其溶血性和注射副反应而无法注射给药的难题。前期研究初步证实了可行性，但尚需深入验证。 海星中的甾体皂苷类成分研究面临同样难题而使其应用前途存疑。申请者从3种海星中发现了12个可能主要基于诱导凋亡作用抗胶质瘤的、结构新颖的甾体皂苷，但结构多样性和信号通路尚未完全阐明，无法得到明确的构效关系结论，动物体内试验亦不完善。 本项目拟进一步分离鉴定面包海星和中华五角海星中的皂苷成分，结合结构修饰获得更多及足量样品，明确构效关系；阐明确切抗胶质瘤分子机制；制备皂苷缓释制剂，通过间质化疗途径研究其体内活性、毒性和作用机制。 该研究将可为解决皂苷成药性的三大难题提供资料和借鉴，为海星甾体皂苷的应用前途提供依据。

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的三大难题。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，以克服其难突破血脑屏障的障碍，又规避因其溶血性和注射副反应而无法注射给药的难题。故在前期通过对太白银莲花三萜皂苷研究初步证实可行性的基础上，选取面包海星和中华疣海星为研究对象，以其所含海星甾体苷的体内外抗胶质瘤活性、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，从两种海星中分离鉴定各类成分127种（新鉴定112种），其中新化合物47个，包括海星甾体苷98种（新鉴定82种）；完成了药理活性测试，获得14种具有显著抑制胶质瘤增殖活性的成分；完成了活性显著、具有结构代表性的1个海星皂苷和1个多羟基甾体苷抗胶质瘤的作用机制研究，初步明确了其分子机制；发现了1种海星皂苷的功能基因SCUBE3，这是首次在胶质瘤上发现药物通过下调SCUBE3阻滞细胞周期、抑制细胞增殖；初步分析了这些海星甾体苷抗胶质瘤活性的构效关系；研究了1种海星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，特别是制备了其缓释制剂，验证了海星皂苷采用间质化疗途径用于抗胶质瘤治疗以规避溶血性和注射毒副反应的可行性。. 本项目已发表期刊论文6篇，其中SCI收录论文5篇；在学术会议交流11篇，其中2篇论文获奖；获国家发明专利授权1项；部分成果作为支撑内容之一获省科技一等奖2项；培养研究生3人。研究成果从海星甾体苷的角度，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，为发掘新型胶质瘤化疗药物提供了1个先导化合物；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。