A water-soluble hyperbranchend β-glucan

extracted from sclerotia of Pleurotus tuber-regium was fractionated to obtain the fractions with different molecular weight.The polysaccharide fractions were treated with chlorosulfonic acid to synthesize sulfated derivatives.The antitumor activities of the water-soluble hyperbranched polysaccharide fractions and their sulfated derivatives were evaluated by in vivo test using SARCOMA 180 xenografted BALB/C mice

and in vitro measurement against HepG2 cell

respectively.The effect of introduction of sulfate groups in the polysaccharide on antitumor activities was compared with that of the native polysaccharides by morphological

histological and ELISA methods.The results indicated that the native polysaccharides

in the radius of gyration(〈S2〉z1/2) range from 42.5 nm to 113 nm

exhibited significantly inhibition impact on the xenografted tumor cell growth and antiproliferative activities against HepG2 cell in vitro. The antitumor activities of the sulfated derivatives increased progressively with the 〈S2〉z1/2 change from 17.8 nm to 34.9 nm.Mechanism study indicated that the native and sulfated glucans inhibited the proliferation of HepG2 cell through inducing the tumor cells apoptosis in a time dependent way.Immunological test demonstrated that both the native polysasaccharide and its sulfated derivatives using low dose (20 mg/kg) increased production of tumor necrosis factor alpha (TNF-α) in mouse plasma while the native one decreased amount of TNF-α using high does (60 mg/kg) with or without liopolysaccharide (LPS) stimulation.