Antitumor and immunomodulatory activity of polysaccharide isolated from Trametes orientalis

A water-soluble polysaccharide (TOP-2) was isolated from Trametes orientalis, consisting of galactose, glucose, mannose, and arabinose with the molar ratios of 5.79:5.77:3.45:1, having an average molecular weight of 63 kDa. The antitumor and immunomodulatory activity of TOP-2 were determined in Lewis lung carcinoma (LLC) tumor-bearing mice. The results revealed that TOP-2 not only could efficaciously restrain the growth of LLC in mice, but also effectively increase the body weight and relative spleen/thymus weight. In addition, TOP-2 remarkably enhanced splenocyte proliferation, notably stimulated phagocytotic function of macrophages, and strikingly promoted the expression of serum cytokines. These findings indicate that TOP-2 exert antitumor activity in vivo potentially by improving immune function. TOP-2 could be empoldered as a potential supplementary agent for cancer treatment.