Preparation and structural characterization of acid-extracted polysaccharide from Grifola frondosa and antitumor activity on S180 tumor-bearing mice

In this study, an acid-extracted polysaccharide (GFP-A) was extracted from the fruiting bodies of G. frondosa with 1 % hydrochloric acid solution. Our study aimed to imitate the processes of digestion, absorption and antitumor activities of polysaccharides from G. frondosa under the acid environment of stomach in the body. The preliminary structural analysis resulted that GFP-A (about 1.10 × 106 Da) was a neutral polysaccharide composed of xylose, mannose, glucose (molar ratio: 0.12:1.00:6.98) with α-type glycosidic linkages. Additionally, antitumor activities on S180 tumor-bearing mice showed that GFP-A could effectively inhibit the growth of S180 tumor cells by protecting immune organs (thymus and spleen), activating immune cells (NK cells, lymphocytes and macrophages), upregulating the secretion of serum cytokines (TNF-α, IL-2 and IFN-γ) in vivo. H & E staining and cell cycle determination further demonstrated that GFP-A could induce S180 tumor cells apoptosis via arresting them in G1 phase. These results demonstrated that GFP-A could provide a theoretical basis for treatment of cancer.