Antitumor and Immunomodulating Activities of Exopolysaccharide Produced by Big Cup Culinary- Medicinal Mushroom Clitocybe maxima (Higher Basidiomycetes) in Liquid Submerged Culture.

Water-soluble polysaccharides extracted from mushrooms have been found to have some physiological effects. In this study, exopolysaccharides (EPSs) were extracted by alcohol precipitation from cultivated broth of the mushroom Clitocybe maxima. EPSs with molecular weights of 10(4) and 10(5) Da were obtained by ultrafiltration; they are referred to as EPA and EPB, respectively. The major components of these EPSs were glucose, galactose, mannose, rhamnose, and arabinose. ICR mice with artificially induced metastatic pulmonary tumors were fed a daily diet containing EPA or EPB at doses of 8, 20, or 50 mg/kg. Results showed that the proliferation of pulmonary sarcoma lesions was lower in the groups fed EPS. In addition, the numbers of total T cells, CD4+ cells, CD8+ cells, and macrophages significantly increased in EPS-fed mice compared with the negative control group. The antitumor and immunomodulating effects observed in the EPB-fed groups were higher than those of EPA-fed groups. These results demonstrate the ability of EPSs of C. maxima to inhibit tumor cells while enhancing immune response.