Isolation and structural characterization of a novel polysaccharide from Hericium erinaceus fruiting bodies and its arrest of cell cycle at S-phage in colon cancer cells.

The fruiting body of Hericium erinaceus has been used to treat digestive system disorder-related diseases for over 2000 years in China. A novel polysaccharide, HEFP-2b, was obtained from H. erinaceus fruiting bodies. Physical and chemical analysis showed that HEFP-2b consisted of fucose, galactose, glucose, and mannose in molar ratio of 11.81:22.82:44.28:21.09, and that its molecular weight was 3.252 × 104 Da. The backbone of HEFP-2b consisted of →6)-linked-α-D-Glcp-(1→ and →4)-β-D-Galp-(1→ and →3,6) -α-D-Manp linkage, with two side-branching units of (1→ and →6)-β-D-Galp and (1→ and →4)-α-D-Manp, terminated by Glc and Fuc. The results of the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and cell cycle arrest experiments revealed that HEFP-2b considerably inhibited the growth of colon cancer cells (HCT-116) in vitro. The growth inhibitory effects of HEFP-2b correlated with their ability to arrest the cell cycle at the S-phase. Our results will provide valuable information for future studies on HEFP-2b as a novel health-promoting functional food ingredient that can be used for treating colon cancer.