Effect of a polysaccharide fraction from Grifola frondosa on immune response in mice

The biological and immunomodulating activities of polysaccharide fraction (GF-1), an antitumor poysaccharide fraction from cultured fruiting bodies of Grifola frondosa, was examined in mice. GF-1 showed no cytocidal effect on culturing tumor cells. However, GF-1 induced resistance against Sarcoma 180 in ICR mice which had completely regressed from the tumor by the effect of GF-1. The administration of GF-1 into mice increased the weights or cell numbers of spleen, and peritoneal cavity. GF-1 enhanced the antigen specific antibody response and carbon clearance activity, whereas GF-1 did not show polyclonal B cell activation and mitogenic activities, and the effect on delayed type hypersensitivity.