Oxidative stress in retinal pigment epithelial cells: protective effect of wood‐derived phenolic compounds

Abstract

AbstractPurpose Oxidative stress is related to chronic diseases including age‐related macular degeneration (AMD), which is the leading cause of blindness in the elderly worldwide. Functional roles of wood‐derived phenolic compounds such as flavonoids, phenolic acids, tannins and stilbenes are not well known, but some of them are effective antioxidants capable of providing defence against oxidative stress. Besides reducing ROS production by their antioxidant activity, phenolics can also activate the expression of phase II genes via the activation of transcription factors, such as Nfr2.Methods In this work, the protective effect of wood phenolics against oxidative stress were determined by pre‐incubating ARPE‐19 cells in medium containing wood compounds (pinosylvin, piceatannol, trans‐resveratrol or pinosylvin monomethyl ether) at different concentrations. After pre‐incubation with phenolics, cells were treated with oxidative stress causing agent, hydroquinone, for 24 hours. The viability of cells was determined by using MTT assay. To elucidate the mechanisms behind the phenolics‐mediated protection against oxidative stress and inflammation, the activity of genes such as Nrf2, IL‐6 and p62 was determined.Results Wood‐derived phenols were well tolerated by the cells and some of the compounds such as pinosylvin were able to increase the viability of cells in response to induced oxidative stress.Conclusion These results suggest that wood‐derived phenolic compounds can provide additional protection against oxidative stress in retinal cells.