Structural characterization and in vitro hepatoprotective activity of a novel antioxidant polysaccharide from fruiting bodies of the mushroom Pleurotus ferulae

In the present study, three novel antioxidant polysaccharides (G-1, AG-1, and AG-2) were isolated and purified from Pleurotus ferulae using mouse erythrocyte hemolysis inhibitory activity as an indicator. These components showed antioxidant activity at the chemical and cellular levels. Given that G-1 displayed superior performance in protecting the human hepatocyte L02 cells against oxidative damage caused by H2O2 compared to AG-1 and AG -2 and had a higher yield and purification rate, the detailed structure of G-1 was further characterized. G-1 mainly contains six kinds of linkage type units as A: & RARR;4,6)-& alpha;-D-Glcp-(1 & RARR;, B: & RARR;3)-& beta;-D-Glcp-(1 & RARR;, C: & RARR;2,6)-& beta;-D-Glcp-(1 & RARR;, D: & beta;-D-Manp(1 & RARR;, E: & RARR;6)-& beta;-D-Galp-(1 & RARR;, F: & RARR;4)-& beta;-D-Glcp-(1 & RARR;. Finally, the potential in vitro hepatoprotective mechanism of G-1 was discussed and elucidated. Results suggested that G-1 can protect L02 cells from H2O2- induced damage by reducing the leakage of AST and ALT from the cytoplasm, enhancing the activities of SOD and CAT, and suppressing lipid peroxidation and production of LDH. G-1 could further reduce the production of ROS, stabilize mitochondrial membrane potential and maintain cell morphology. Hence, G-1 could be a valuable functional food with antioxidant and hepatoprotective activities.