Characterization and Antitumor Effect of a Novel Polysaccharide from Grifola frondosa

摘要

A novel polysaccharide, MZF, with a molecular mass of 23 kDa was isolated from Grifola frondosa. Results from methylation and ~1H NMR led to the conclusion that MZF is a heteropolysaccharide consisting of -> 6)-α-D-Galp-(1-> (36.2%), ->3)-α-L-Fucp-(1-> (14.5%), ->6)-α-D-Manp-(1-> (9.4%), ->3)-β-D-Glcp-(1-> (10.1%), α-D-Manp-(1-> (23.2%), and ->3,6)-β-D-Glcp-(1 -> (6.5%). Although MZF did not affect the proliferation of colon-26 cells in vitro, it significantly inhibited tumor growth in BALB/ cA mice inoculated with colon-26 cancer cells. Moreover, MZF significantly induced the proliferation of splenocytes and peritoneal macrophages. The mRNA expression of IL-12p40, IL-2 and IFN-γ were increased significantly in MZF-treated spleen. Furthermore, MZF augmented the percentage of IFN-γ-produoing cells in both splenic CD4~+ and CD8~+ T cells and tumor infiltrating CD4~+ and CD8~+ T cells and enhanced the cytotoxic activity of NK cells and CTLs. These results indicate that MZF is a novel affective immunomodulator that has antitumor activity associated with induced cell-mediated immunity.