蛹、米虫草多糖含量及抗氧化活性比较研究

Comparative Study on Polysaccharide Content and Antioxidant Activity of Cordyceps militaris and Cordyceps oryzae

旨在研究不同来源北虫草子实体多糖的含量差异以及分级醇沉各组分的抗氧化活性差异。通过热水浸提、分级醇沉法分别获得蛹虫草多糖(Cordyceps militaris polysaccharide,CMP)、米虫草多糖(Cordyceps oryzae polysaccharide,COP);以DPPH自由基清除率、羟基自由基(·OH)清除率和铁离子还原能力法(ferric reducing antioxidant power,FRAP)评价两种多糖的体外抗氧化活性;构建H2O2致PC12细胞氧化损伤模型,比较两种虫草多糖对氧化损伤的PC12细胞的保护作用。不同乙醇浓度沉淀获得的虫草多糖中,米虫草多糖提取率及含量高于蛹虫草多糖;米虫草多糖对DPPH自由基、·OH清除率分别可达66.43%、69.22%,蛹虫草多糖可达73.69%、73.50%;FRAP法测得蛹虫草多糖抗氧化能力较强。细胞试验结果表明,氧化损伤的PC12细胞经两种多糖处理后细胞存活率皆有不同程度的提升,呈浓度依赖性,蛹虫草多糖组细胞存活率最高可达90.45%,米虫草多糖组细胞存活率最高可达82.62%。以蚕蛹为培养基的蛹虫草在多糖提取率及含量方面低于以大米为培养基的米虫草,但其多糖对自由基清除能力及PC12细胞保护作用优于米虫草多糖,具有较好的抗氧化能力。

The aim of this study was to study the difference of polysaccharide content in fruiting body of Cordyceps militaris from different sources and the difference of antioxidant activity of each component of graded alcohol precipitation.Cordyceps militaris polysaccharides(CMP)and Cordyceps oryzae polysaccharide(COP)were obtained by hot water extraction and fractionated alcohol precipitation.1,1-diphenyl-2-picrylhydrazyl(DPPH)radical scavenging rate,·OH scavenging rate and ferric reducing antioxidant power(FRAP)were used to evaluate the antioxidant activity of the two polysaccharides in vitro.The oxidative damage model of PC12 cells induced by H2O2 was established,and the protective effects of two kinds of Cordyceps polysaccharides on oxidative damaged PC12 cells were compared.In the Cordyceps polysaccharide precipitated by different ethanol concentration,the extraction rate and content of COP were higher than those of CMP.The scavenging rates of DPPH free radicals and·OH of COP were 66.43%and 69.22%,respectively,and the reduction rates of CMP were 73.69%and 73.50%.FRAP showed that CMP had strong antioxidant capacity.The results of cell experiments showed that the cell survival rate of oxidative damaged PC12 cells increased in varying degrees after treatment with two kinds of polysaccharides in a concentration-dependent manner.The highest cell survival rate was 90.45%in CMP group and 82.62%in COP group.The extraction rate and content of polysaccharides of Cordyceps militaris with silkworm pupa as medium were lower than those of Cordyceps oryzae with rice as medium,but its polysaccharides were better than COP in scavenging free radicals and protecting PC12 cells.