Cytoprotective effect of selenium polysaccharide from Pleurotus ostreatus against H2O2-induced oxidative stress and apoptosis in PC12 cells

One main fraction of Selenium-enriched Pleurotus ostreatus (P. ostreatus) polysaccharide (Se-POP-1) was extracted and purified by DEAE-52 and sephadex G-100. Se-POP-1 was an approximate homogenous polysaccharide with an average molecular weight of 1.62 × 104 Da, and mainly composed of glucose, mannose and galactose, with molar ratio of 5.30:1.55:2.14. The absorption peaks at 941 cm−1 and 1048 cm−1 in FT-IR analysis were ascribed as C-O-Se and Se=O bonds. Pr-treatment of Se-POP-1 (400 μg/mL) increased the cell survival of H2O2-stimulated PC12 cells and inhibited intrinsic apoptosis and oxidative stress in H2O2-stimulated PC12 cells via limiting DNA degradation and decreasing the reactive oxygen species (ROS) generation. In addition, up-regulation of anti-apoptotic protein Bcl-2, down- regulation of pro-apoptotic protein Bax, cleaved caspase 3, and cytochrome c were also observed. Se-POP-1 presented an obvious effect to alleviate oxidative damage and apoptosis in PC12 cells induced by H2O2. Therefore, Se-POP-1 possessed potent antioxidant and biological activities with the ability to prevent oxidation via scavenging ROS and free radicals in cells. It could be developed as organic selenium dietary supplement and functional food.