Plant flavonol quercetin and isoflavone biochanin A differentially induce protection against oxidative stress and inflammation in ARPE-19 cells

In this work, differential ability of plant flavonol quercetin and plant isoflavone biochanin A to modulate oxidative stress and inhibit inflammation-related responses was investigated using human retinal pigment epithelial cells (RPE) at gene expression level. Quercetin protected cells from oxidative stress-induced cell death, whereas biochanin A had no statistically significant protective effects. Quercetin reduced the expression of cytokines IL-6 and IL-1?? in cells treated with H₂O₂, and expression levels of Nrf2 and HO-1 were increased by quercetin treatment suggesting protective function against oxidative stress. Our data indicate that quercetin may protect cells by inhibiting the production of pro-inflammatory factors such as IL-6, and by inducing the expression of ROS-catalyzing phase II proteins such as HO-1. Therefore, plant extracts rich in flavonol quercetin may be an interesting resource for functional food products and other foods targeted for reduced risks of age-related macular degeneration.