紫球藻胞外多糖抗氧化和免疫调节活性的研究

Research on antioxidant function and immumodulatory function of Porphyridium creuntum extracellular polysaccharides

采用密闭微波法降解紫球藻胞外多糖。通过测定多糖对羟自由基OH·、超氧阴离子O2-·和二苯代苦味酰基自由基DPPH·的清除效果及对小鼠单核-巨噬细胞RAW264.7和淋巴细胞的增殖效果,考察低分子量紫球藻多糖的体外抗氧化活性和免疫调节活性。结果表明,在一定的浓度范围内,降解后的紫球藻多糖对OH·、O2-·和DPPH·的清除能力与浓度呈正相关性,它们的半抑制率IC50分别为0.619,0.114和0.015mg/mL,表明紫球藻胞外多糖具有体外抗氧化活性。溶液浓度在50～200μg/mL的多糖都表现出体外免疫促进作用,与对照组相比,100μg/mL的多糖对巨噬细胞RAW264.7的促进作用最大,其增值指数为1.72。200μg/mL的多糖对脾淋巴细胞的增值指数为2.11。

The extracelluar polysaccharides of Porphyridium creuntum were degraded to obtain low molecular weight oligosaccharide by closed-microwave method. In order to evaluate the antioxidant activity and immumodulatory function, we investigated the scavenging effects of degraded polysaccharide on hydroxyl radical （OH.）, superoxide anion （O2-·） and 2,2-Diphenyl-1-picrylhydrazyl radica （DPPH.）, as well as the proliferation effects on peritoneal macrophage RAW264.7 and splenic lymphocyte of mouse. The results showed that the scavenging activity of degraded polysaccharide on OH·O2-·and DPPH. presented plus-correlation with the polysacchafide concentration. The half inhibition concentration （IC50）were 0.619, 0.114 and 0.015 mg/mL, respectively. The polysaccharide exhibited obvious immunity stimulation at concentration of 50 - 200 μg/mL. In contrast to the control test, the peritoneal macrophage RAW264.7 were proliferated furthest at 100μg/mL polysaccharide, and the proliferation index was 1.72. The maximal proliferation index of splenic lymphocyte was 2.11 at sample concentration of 200 μg/mL.