Structural characterization and in vitro hepatoprotective activity of polysaccharide from pine nut (Pinus koraiensis Sieb. et Zucc.)

A new purified polysaccharide (PNP40c-1) with a molecular weight of 2.06 x 10(5) Da was obtained from pine nuts (Pinus koraiensis Sieb. et Zucc.). Structural analysis indicated that PNP40c-1 is a homogeneous heteropolysaccharide composed of arabinose, rhamnose and glucose in a molar ratio of 2.98: 1.00: 0.52. The major backbone consisted of -> 3,4)-alpha-L-Arap(1 ->, -> 4)-alpha-L-Arap3Me(1 ->, -> 3)-alpha-L-Rhap(1 -> and -> 6)-beta-D-Glcp(1 ->, and the side chain is beta-D-Glcp-(1 -> linked at C4-position of. 3,4)-alpha-L-Arap(1 ->. In addition, the hepatoprotective effect of PNP40c-1 was investigated by human hepatocyte cell line L02 treated with carbon tetrachloride (CCl4). Results suggested that PNP40c-1 could protect L02 cells from CCl4-induced damage by enhancing the activities of antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), increasing the level of non-enzymatic antioxidant glutathione (GSH), suppressing lipid perioxidation and further reducing the leakage of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Hence, PNP40c-1 could be a promising functional food to serve as hepatoprotective agent.