Antioxidant and immunological activity in vitro of polysaccharides from Gomphidius rutilus mycelium

Two novel polysaccharide fractions, GRMP1 and GRMP2, were isolated from the mycelium of Gomphidius rutilus through submerged fermentation. GRMP1 and GRMP2 had similar average molecular weights (35 and 31 kDa, respectively), and were composed of glucose and xylose at molar ratios of 0.46:1 and 0.63:1, respectively. In vitro antioxidant tests showed that GRMP1 and GRMP2 partly scavenged superoxide radical but almost had no scavenging effect on 1,1-diphenyl-2-picrylhydrazyl free radical. The effect of GRMP1 on hydroxyl radicals was stronger than that of GRMP2. Both GRMP1 and GRMP2 had relatively low reducing power and significant lymphocyte proliferation activity. In the presence of concanavalin A or lipopolysaccharide as mitogens for lymphocytes, the lymphocyte proliferation activity increased for GRMP1 but not for GRMP2 within the test dosage range.