硒多糖的抗氧化活性及与过氧化氢酶协同作用的研究

Research on Antioxidative Activity of Se-polysaccharide and Synergistic Action of Se-polysaccharide and Catalase

对自行培养的富硒蛹虫草中提取的有机硒多糖进行抗氧化活性研究。采用循环伏安法(CV),在铂电极表面构筑支撑磷脂双层膜(Supported bilayer lipid membrane,s-BLM),以0.1mol/LKCl-1.0mmol/LK3Fe(CN)6-1.0mmol/LK4Fe(CN)6为探针溶液,利用Fenton体系中Fe2+和H2O2反应产生的羟自由基对模拟生物膜的损伤程度考察有机硒多糖的生物活性。结果表明:羟自由基使s-BLM的通透性增强,造成膜体损伤;而在硒多糖存在下,可使羟自由基对膜的这种损伤受到抑制,硒多糖能够清除自由基保护生物膜;采用紫外-可见(UV-Vis)吸收光谱法比较研究不同浓度的过氧化氢酶与硒多糖对羟自由基的清除率。结果表明:硒多糖对羟自由基的清除效果好于过氧化氢酶,且当体系中硒多糖和过氧化氢酶共存时,二者对羟自由基的清除效果具有协同作用。进一步讨论了硒多糖抗氧化活性的可能机理,为有机硒多糖在保护生物膜、抗氧化活性方面的开发与利用提供科学的理论依据。

The antioxidative activity of organic Se-polysaccharide drew from the selenium enriched cordyceps militaris cultured by ourselves was investigated.To study the biological activity of organic Se-polysaccharide,the degree of injury to the simulating biomembranes caused by hydroxyl free radicals which were produced from the reaction of Fe2 ＋ and H2O2 in the Fenton system was examined,by means of voltammetry（CV）,constructing Supported Bilayer Lipid Membrane（s-BLM）,as well as using 0.1 mol/L KCl,1.0 mmol/L K3Fe（CN） 6 and 1.0 mmol/L K4Fe（CN） 6 as probe solutions.The results showed that hydroxyl free radicals enhanced the permeability of s-BLM,and damnified the membrane bodies as well.On the other hand,the injury to biomembranes caused by hydroxyl free radicals was restrained in the presence of Se-polysaccharide,as Se-polysaccharide could eliminate free radicals and,therefore,protect biomembranes.In addition,the clearance rates of hydroxyl free radicals by various concentrations of catalase and Se-polysaccharide were investigated using Ultraviolet-visible（UV-Vis） absorption spectra.The results showed that Se-polysaccharide had a better clearance effect on hydroxyl free radicals than catalase.And when Se-polysaccharide and catalase coexisted in systems,there was a synergistic clearance effect on hydroxyl free radicals.The possible mechanism of the antioxidative activity of Se-polysaccharide was further discussed.It would provide a scientific and theoretical basis for the exploitation and application of organic Se-polysaccharide on protecting biomembranes and the antioxidative activity.