Cyanidin-3-glucoside prevents hydrogen peroxide (HO)-induced oxidative damage in HepG2 cells

Objective: The aim of this study is to evaluate the cytoprotection and potential molecular mechanisms of cyanidin-3-glucoside (C3G) on hydrogen peroxide (HO)-induced oxidative damage in HepG2 cells. Methods: The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was carried out to examine the viability of HepG2 cells exposure to HO or C3G. Meanwhile, the antioxidant properties of C3G were measured by determining the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT) and the malondialdehyde (MDA) levels. Flow cytometry was employed to determine HepG2 cells apoptosis, and HepG2 cells were stained with Hoechst 33342 to observe cell morphology. 2′,7′-dichlorofluorescin diacetate (DCFH-DA) was used to evaluate the production of intracellular reactive oxygen species (ROS). Finally, the expression of apoptosis-related protein was monitored through western blot analysis. Results: HepG2 cells induced with HO presented a remarkable decrease in cell viability that was suppressed when HepG2 cells were interfered with C3G (2.5–10 μM). C3G interference memorably and dose-dependently inhibited HO-induced intracellular ROS and MDA overproduction, while C3G treatment markedly increased HO-induced the activities of intracellular SOD, GSH-Px and CAT. Eventually, the relative proteins expression levels of p53, cleaved caspase-9/3, cytochrome c, Fas-L, Fas, FADD and caspase-8 were substantially up-regulated in HO-triggered HepG2 cells, and Bax/Bcl-2 ratio and the relative protein expression levels of PARP were dramatically down-regulated. However, the expression levels of these relative proteins were reversed in C3G-interfered HepG2 cells. Conclusions: C3G could protect HepG2 cells from oxidative damage, and the effects that were mediated by the mitochondrial apoptotic pathways and the external pathways.