Anthocyanins belong to phenolic pigments and are known to have various pharmacological activities. This study aimed to investigate whether anthocyanins could inhibit hydrogen peroxide (H2O2)-induced oxidative damage in human retinal pigment epithelial ARPE-19 cells. Our results indicated that anthocyanins suppressed H2O2-induced genotoxicity, while inhibiting reactive oxygen species (ROS) production and preserving diminished glutathione. Anthocyanins also suppressed H2O2-induced apoptosis by reversing the Bcl-2/Bax ratio and inhibiting caspase-3 activation. Additionally, anthocyanins attenuated the release of cytochrome c into the cytosol, which was achieved by interfering with mitochondrial membrane disruption. Moreover, anthocyanins increased the expression of heme oxygenase-1 (HO-1) as well as its activity, which was correlated with the phosphorylation and nuclear translocation of nuclear factor-erythroid-2 related factor 2 (Nrf2). However, the cytoprotective and anti-apoptotic effects of anthocyanins were significantly attenuated by the HO-1 inhibitor, demonstrating that anthocyanins promoted Nrf2-induced HO-1 activity to prevent ARPE-19 cells from oxidative stress. Therefore, our findings suggest that anthocyanins, as Nrf2 activators, have potent ROS scavenging activity and may have the potential to protect ocular injury caused by oxidative stress.
Keywords: Anthocyanins; Nrf2/HO-1; ROS; apoptosis; genotoxicity.