Cyanidin-3-glucoside prevents hydrogen peroxide (H₂O₂)-induced oxidative damage in HepG2 cells

The aim of this study is to evaluate the cytoprotection and potential molecular mechanisms of cyanidin-3-glucoside (C3G) on hydrogen peroxide (H₂O₂)-induced oxidative damage in HepG2 cells.

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 H₂O₂ 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.

HepG2 cells induced with H₂O₂ 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 H₂O₂-induced intracellular ROS and MDA overproduction, while C3G treatment markedly increased H₂O₂-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 H₂O₂-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.

C3G could protect HepG2 cells from oxidative damage, and the effects that were mediated by the mitochondrial apoptotic pathways and the external pathways.