The biological activities of the antitumor drug Grifola frondosa polysaccharide

Grifola frondosa, a polypore fungus that grows at the base of trees, is an edible and medicinal mushroom with a large fruiting body characterized by overlapping caps. Japanese scholars found that Grifola frondosa polysaccharide or D-fraction is the major biologically active ingredient, which is a protein-bound glucan or proteoglucan, consisting of β-glucan (either β-1,6-linked glucan with β-1,3 branches or β-1,3-linked glucan branched with β-1,6 glucosides, but it also contains d-xylose, d-fucose, d-mannose, l-arabinose, uronic acid, and galactose with largely unknown linkages. The Grifola frondosa polysaccharides with different molecular weight and monosaccharide compositions can be obtained by using different extraction methods, such as hot water extraction, acid or alkaline extraction, or microwave extraction methods from the fruiting bodies, mycelia or the fermentation broth. Grifola frondosa polysaccharide-based drug was developed in China and approved as an adjunctive therapeutic drug for cancer treatment by the State Food and Drug Administration (SFDA) in 2010. There are eight fungal glycan-based drugs, some of them have to be injected in order to be effective in vivo but the Grifola frondosa polysaccharide-based drug can be taken either orally or by injection. In this article, based on the search results of Chinese VIP, CNKI, Wanfang database and PubMed database, 108 independent studies were summarized. The chemical structure, the antitumor, immunomodulatory, anti-diabetic, anti-hyperlipidemia, and antiviral activity and molecular mechanisms of GFP are reviewed and discussed. Our goal is to provide a molecular picture that would allow in-depth evaluation of Grifola frondosa polysaccharide as an adjunctive drug for cancer therapy.