Abstract: The anti-aging effect of polysaccharides from the fruiting body of Pleurotus geesteranus (PFP) on a D-galactoseinduced aging mouse model. The aged mouse model was established by the injection of D-galactose. These mice were simultaneously administrated by gavage with PFP at different dosages for 42 days. At 12 h after the last administration, the activities of catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), and the contents of malondialdehyde (MDA) in serum, liver and brain were measured by using commercial reagent kits. The activities of serum aspartate aminotransferase (AST), alkaline phosphatas (ALP) and alanine aminotransferase (ALT), and spleen and thymus indexes were also determined. The liver and brain were taken for histological analysis through HE staining. The results showed that PFP had antagonism effects on D-galactose-induced aging in mice, and could increase the activities of CAT, SOD and GSH-Px and reduce MDA levels in serum, and liver and brain tissues. Compared with the aging model group, the activities of serum AST, ALT, ALP in the medium- and high-dosage PFP group significantly decreased (P < 0.05, P < 0.01) in parallel with a highly significant increase in both spleen index and thymus index (P < 0.01). Histological sections showed that PFP displayed a significant protective effect on liver and brain injury induced by D-galactose. In conclusion, PFP has significant antioxidant and anti-aging effects. The underlying mechanism might be related to improving antioxidant function and enhancing immune function in the body.

Key words: Pleurotus geesteranus, polysaccharide, D-galactose, antioxidant, anti-aging