A selenium polysaccharide from Platycodon grandiflorum rescues PC12 cell death caused by H2O2 via inhibiting oxidative stress

In this paper, a selenium polysaccharide (PGP1) was isolated from the radix of Platycodon grandiflorum. We investigated the protective capacity of PGP1 against the hydrogen peroxide (H2O2)-induced oxidative damage in cultured rat pheochromocytoma (PC12) cells. Cells were pretreated with various doses of PGP1 (50, 100 and 200 μg/mL) for 24 h before exposure to 0.5 mM H2O2 for 12 h. Cell viability, LDH release, apoptotic rates, malondialdehyde (MDA) content, antioxidant enzyme superoxide dismutase (SOD) activity and intracellular accumulation of reactive oxygen species (ROS) were determined. The results showed pretreatment of PC12 cells with PGP1 prior to H2O2 exposure inhibited the decrease of cell viability, decreased the apoptotic rates, prevented membrane damage (LDH release) and attenuated intracellular ROS formation in PC12 cells injured by H2O2. Meanwhile, PGP1 increased SOD activity, while it decreased the level of MDA and the production of lipid peroxidation, in PC12 cells after H2O2 exposure. These findings suggested that PGP1 may be considered as a potential useful antioxidant agent in reducing neuronal oxidative damage via inhibiting oxidative stress.