Hepatoprotective effect of a polysaccharide from Crassostrea gigas on acute and chronic models of liver injury.

A water-soluble polysaccharide was isolated from Crassostrea gigas (CGPS-1) by hot-water extraction, isoelectric precipitation, hydrolysis and ultrafiltration without using ethanol. Based on the calibration with Dextran, CGPS-1 had a molecular weight of approximately 6.5×10(6) Da. CGPS-1 was analyzed using high-performance liquid chromatography, Fourier-transform infrared spectroscopy and (1)H and (13)C nuclear magnetic resonance spectroscopy. Based on the data, CGPS-1 was found to be a uniform glucose polymer. The protective effect of CGPS-1 on acute carbon tetrachloride- and chronic ethanol-induced liver injury was investigated in mice. Treatment with CGPS-1 decreased serum aspartate aminotransferase (AST), serum alanine aminotransferase (ALT), and malondialdehyde (MDA) levels; increased superoxide dismutase (SOD) activity; and improved hepatic injury in both the acute and chronic models of liver injury in mice. These results suggest that CGPS-1 possesses potent hepatoprotective activity.