富硒螺旋藻清除氧自由基的初步研究

目的与方法:采用化学发光法研究富硒螺旋藻提取液、硒藻蓝蛋白、硒藻多糖、亚硒酸钠对超氧阴离子(_O2?)和羟自由基(·OH)的清除作用。结果:当体系中提取液浓度达400μg/ml时,富硒比未富硒螺旋藻提取液对_O2?的清除率提高30%,对·OH的清除率提高20%;硒藻蓝蛋白_比藻蓝蛋白对_O2?和·OH的清除作用有所提高,并呈现明显的剂量相关性,O2?50%清除率蛋白浓度为500μg/ml,·OH50%清除率蛋白浓度为125μg/ml;硒藻多糖对氧自由基具有极强的清除效率,_O2?和·OH50%清除率时的浓度分别为12μg/ml和60μg/ml;另外,在实验浓度范围,未检测到亚硒酸钠对超_O2?和·OH具有清除作用。结论:富硒螺旋藻可能因硒的代谢而产生活性有机硒态如硒藻蓝蛋白、硒多糖等,从而提高其清除自由基活性。

THE SCAVENGING EFFECTS OF SE ENRICHED SPIRULINA PLATENSIS ON OXYGEN FREE RADICALS

Objective and Methods:The scavenging effects of the extracts, phycocyanin and polysaccharose from Spirulina platensis (S.P) or from selenium enriched S.P (Se-S.P), and sodium _ selenite on superoxide anions( O2? )and hydroxyl radicals (·OH) were investigated respectively with chemoluminescence technique. Results:The extract, Se-phycocyanin and Se-polysaccharose from Se-S.P had higher scavenging effect on both kinds of active oxygen radicals than those from S.P and the scavenging _ rates of extract on O2 ? and ·OH were enhanced about 30%and 20% at a concentration of 400μg/ml.Those effects of Se-phycocyanin were characterized dose-dependently and the concentration of 50% scavenging rate on superoxide anions was above 500 μg/ml. With increase of the concentration of Se-phycocyanin, the scavenging rate on ·OH was elevated steadily and 50% scavenging rate was found at protein concentration above 125μg/ml. The scavenging effect of the Se-polysaccharides on oxygen free radicals was more _ noticeable and the concentration for 50% scavenging rate on ·OH and O2 ? were 60 μg/ml and 12 μg/ml _ respectively. However, there was no evidenced scavenging effect of sodium selenite on both ·OH and O2 ? . Conclusion : The active organic Se-containing molecules such as Se-containing proteins and Se polysaccharides, which were produced by selenium metabolism in microalgae, might contribute to the scavenging effects of Se enriched S.P. on oxygen free radicals.