硒化党参多糖对巨噬细胞的抗氧化作用及其机制的研究

Studies have demonstrated that selenium modified polysaccharide of Chinese herbal medicines have much more and stronger biological activity, such as enhanced immune activity, improved antioxidant properties, etc. Macrophages are the body's first line of defense against infection and are vulnerable to be affected by the oxidative stress caused by free radicals. However, the research on oxidation protective effects on macrophages are still lacking. Therefore, on the basis of preliminary work, the project intends to use purification and separation technology to obtain Codonopsis pilosula polysaccharide and then it was selenizingly modified. The structure of selenizing Codonopsis pilosula polysaccharide will be analyzed by means of chemical analysis and instruments. The oxidative damage model of macrophages will be established. The antioxidant effects of selenizing Codonopsis pilosula polysaccharide will be researched by application of cell biology methods. Meanwhile, the mechanism for the protective effects on macrophages’ oxidative damage will be also researched. The findings will first clarify the selenizing Codonopsis pilosula polysaccharide’s oxidation protective effects on macrophages and reveal the antioxidant mechanism as well. It will further elucidate the relationship between the selenizing polysaccharide’s structure and its antioxidant activity. And it will provide scientific basis for polysaccharide medicines’ design, research and development in the future.

研究已经证实，中药多糖硒化修饰后，具有更多、更强的生物活性，如增强免疫活性、提高抗氧化性能等。鉴于巨噬细胞（Macrophages）是机体抵抗感染的第一道防线，且易受到自由基等氧化应激的影响，而对于其氧化保护的研究极为欠缺。因此在前期工作基础上，本项目拟采用纯化分离技术获得党参多糖，并对其进行硒化修饰；通过仪器和化学分析手段对硒化党参多糖结构进行分析；建立巨噬细胞氧化损伤模型，应用细胞生物学手段研究硒化党参多糖的抗氧化作用，并进行巨噬细胞氧化损伤的保护作用机制研究。研究结果将首次明确硒化党参多糖对巨噬细胞氧化保护作用，同时揭示其抗氧化机制，进一步阐明硒化多糖的结构与其抗氧化活性的关系，可以为今后多糖类药物的设计、研究和开发提供科学依据。

本项目采用纯化分离技术制得党参多糖，运用正交试验的方法，对其进行硒化修饰，并通过紫外、红外、质谱、核磁共振等波谱学方法对硒化党参多糖结构进行了结构分析。本课题成功建立了小鼠巨噬细胞系RAW264.7细胞氧化损伤模型，应用多种细胞生物学手段研究硒化党参多糖的抗氧化损伤作用，筛选出硒化党参多糖sCPPS5具有显著的抗氧化损伤作用，并对其进行巨噬细胞氧化损伤的保护作用机制研究。研究发现，硒化党参多糖sCPPS5的抗氧化作用一方面是与其合适的硒含量和糖含量有关，另一方面可能与其分子量、糖苷键的构型、单糖组成等有关。研究还发现，硒化党参多糖sCPPS5的抗氧化作用与Keap1/Nrf2/ARE 信号通路密切相关，在以后的研究中应该运用其他研究手段，进一步研究其确切机制。