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 × 10⁵ 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)-α-l-Arap(1→, →4)-α-l-Arap3Me(1→, →3)-α-l-Rhap(1→ and →6)-β-d-Glcp(1→, and the side chain is β-d-Glcp-(1→ linked at C4-position of →3,4)-α-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.