Abstract: The aim of this study is to evaluate the cytoprotection and potential molecular mechanisms of cyanidin-3-O-glucoside (C3G) on hydrogen peroxide (H2O2)-induced oxidative damage in RAW264.7 cells. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was conducted to determine the viability of RAW264.7 cells exposure to H2O2 or C3G. Meanwhile, we measured the antioxidant properties of C3G by determining the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), nitric oxide (NO) release and malondialdehyde (MDA) levels by enzyme-linked immunosorbent assay (ELISA). 2’,7’-dichlorofluorescin diacetate (DCFH-DA) was employed to evaluate the production of intracellular reactive oxygen species (ROS). Finally, the expression levels of related mRNA/protein were evaluated by reverse transcription polymerase chain reaction (RT-PCR) and Western blot analysis, respectively. The results showed that the H2O2-induced decrease in the cell viability of RAW264.7 cells was remarkably suppressed C3G (6.25–25.00 μmol/L). C3G significantly inhibited the H2O2-induced of overproduction of intracellular ROS, NO release and MDA levels, but increased the activities of intracellular SOD and GSH-Px (P < 0.05). In addition, the relative mRNA and protein expression levels of Mst1, Mst2 and Keap1 were up-regulated, while the mRNA and protein relative expression levels of Nrf2 and HO-1 were down-regulated in the 400 μmol/L H2O2-treated group when compared to the vehicle-treated group. However, the above changes were reversed by intervention with C3G. C3G could exert a cytoprotective effect possibly by activating the Mst/Nrf2 signaling pathway and improving the activities of antioxidant enzymes.

Key words: cyanidin-3-O-glucoside; RAW264.7 cells; oxidative damage; Mst/Nrf2 signaling pathway