Abstract:To improve the yield of crude polysaccharides from Pleurotus citrinopileatus and study its antioxidant and anti-aging activities， the response surface method was applied to optimize the extraction process of crude polysaccharides from P. citrinopileatus. A multi-index evaluation system was constructed. The in vitro antioxidant activity of polysaccharides from P. citrinopileatus was systematically evaluated by detecting DPPH radical scavenging rate， hydroxyl radical scavenging rate， and superoxide anion scavenging rate. With Caenorhabditis elegans as the model organism， the anti-aging activity of polysaccharides from P. citrinopileatus was explored through stress experiments， reproductive experiments， and exercise experiments. The results showed that the extraction parameters for crude polysaccharides from P. citrinopileatus were optimal at an extraction temperature of 53 ℃， extraction time of 2.4 h， and liquid-to-material ratio of 30∶1（mL/g）. Under these conditions， the yield of predicted crude polysaccharide was（18.76±0.16）%. Crude polysaccharides from P. citrinopileatus had a high clearance rate of DPPH free radicals and hydroxyl radicals， respectively， and the maximum scavenging rate for superoxide anion radicals was 11.92%. The crude polysaccharides from P. citrinopileatus can enhance the heat resistance of nematodes and alleviate oxidative stress damage caused by H2O2 and juglone. It can also promote the nematodes to lay eggs， enhance the motility， and increase the body bending frequency and head swing frequency， presenting good anti-aging activity.