Abstract: The present work was undertaken to investigate the antioxidant activity of crude polysaccharides extracted from Fomitopsis pinicola fruiting bodies from different geographical origins: Jilin, Heilongjiang and Yunnan provinces (designated as JFPF, HFPF and YFPF, respectively), Fomitopsis pinicola mycelium (FPM) and its fermentation broth (FPFB). The antioxidant activity was evaluated by determining the scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and hydroxyl radicals and K3Fe(CN)6 reducing power, followed by the evaluation of the protective effects against ultraviolet (UV) radiation and H2O2-induced?oxidative damage in yeast cells. The results showed that the five crude polysaccharides had different antioxidant activities and significantly increased the survival rate of yeast cells under oxidative damage in a dose-dependent manner. The scavenging capacity against DPPH, ABTS and hydroxyl radicals, and the reducing power of YFPF polysaccharides were relatively stronger among these polysaccharides. At 5 mg/mL, the scavenging rates of DPPH, ABTS and hydroxyl radicals were 78.78%, 99.24% and 64.38%, respectively, and the reducing power was 0.84. In addition, the protective effect of FPM polysaccharides against oxidative damage was the strongest, as evidenced by significantly improved survival rate of yeast cells. At 20 mg/mL, the survival rates of yeast cells under UV and H2O2-induced oxidative damage were 75.48% and 48.38%, respectively. This study demonstrated that the antioxidant activity of crude polysaccharides from F. pinicola varied with geographical origin, which will provide a theoretical basis for the exploitation and utilization of F. pinicola.

Key words: Fomitopsis pinicola, crude polysaccharides, oxidative damage, antioxidant activity