Optimization of enzyme-assisted extraction process, antioxidant activity and protective effect on pancreatic β cells of Sanghuangporus vaninii polysaccharides

Using wild type Sanghuangporus vaninii from Changbai Mountain as the raw material, this study investigated the extraction process, antioxidant activity, and protective effect against cell damage on pancreatic β cells of polysaccharide extract from S. vaninii (YSP). The extraction process of YSP was optimized through single-factor experiments and response surface methodology. The monosaccharide composition and structural characteristics were analyzed using HPLC and FT-IR, respectively. The in vitro antioxidant activity of YSP was assessed, and its protective effect on H₂O₂-induced pancreatic β cells was examined. The findings revealed that the optimal extraction conditions for polysaccharides from S. vaninii were: cellulase enzyme amount of 1.5%, enzymolysis duration of 2.0 h, and enzymolysis temperature of 45 ℃. Under these conditions, the polysaccharide extraction rate reached 3.31%. YSP was predominantly composed of mannose, ribose, and rhamnose at a molar ratio of 16.45∶1.18∶1.00 featuring both α- and β-pyranose configurations. The results of antioxidant activity indicated that YSP could significantly scavenge DPPH, ABTS^+·, and O₂^-·. The protective activity of YSP on pancreatic β cells demonstrated that treatment with varying concentrations of YSP significantly inhibited H₂O₂-induced cell damage in INS-1 cells. It was observed that YSP increased cell viability, reduced ROS production and LDH levels, and enhanced the activitives of SOD, CAT, and GSH. These findings provide a basis for further research and development of polysaccharides from S. vaninii as functional foods.