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

Abstract

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 200μg/mL) for 24h before exposure to 0.5mM H₂O₂ for 12h. 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.

Keywords: Antioxidant; H(2)O(2); Neuroprotective; Oxidative stress; PC12 cells; Platycodon grandiflorum; Polysaccharide.