Isolation, purification and physicochemical properties of polysaccharide from fruiting body of Hericium erinaceus and its effect on colonic health of mice

Hericium erinaceus was extracted with boiling water to obtain the crude polysaccharide (HECP) and refined polysaccharide (HERP). HERP was further purified using gradual ethanol precipitation to obtain five sub-fractions. Their physicochemical properties were evaluated, including chemical components, monosaccharide composition and molecular weight. Meanwhile, the effect of HERP on colonic health of mice was investigated by oral administration at dosages of 100, 200 and 400mg/kg of body weight (mg/kgbw), comparing with that of HECP. Results showed that the gradual ethanol precipitation could remarkably increase polysaccharide purity. HERP, HECP and the five purified fractions had different monosaccharide compositions, while the main monosaccharides were Glc and Gal. They all showed similar structure with amorphous appearance. Short-chain fatty acids productions in colonic and cecum contents, and feces of mice were increased in polysaccharide treated groups. Mice administrated with HERP at 400mg/kgbw showed significant reductions in pH values while obvious increases in moisture amounts. This study suggests that gradual ethanol precipitation is available for purification of polysaccharide from Hericium erinaceus and the extracted polysaccharide could improve colonic health.