Redox signaling in diabetic retinopathy and opportunity for therapeutic intervention through natural products

Diabetic retinopathy (DR) is a common serious complication of diabetes that accounts for the leading cause of blindness among the working-age population in developed countries. Despite substantial progress in therapeutic approaches, DR remains highly prevalent, indicating deeper pathomechanism studies are urgently needed. Nowadays, natural products with outstanding safety and efficacy play an increasingly vital role in drug discovery research, and some of them have the potential to facilitate the treatment of DR. In this review, we primarily revisit the contribution of redox signaling and its mediators that might be amenable to targeting DR, including Nuclear factor-kappa B (NF-κB), transforming growth factor-β (TGF-β), matrix metalloproteinases (MMPs), nuclear factor erythroid 2 related factor 2 (Nrf2), advanced glycation endproducts (AGEs), mammalian target of rapamycin (mTOR) as well as microRNAs. Ultimately, we summarize and evaluate the use of natural products to regulate these signaling pathways, which may increase our understanding and ability to target these important molecules and may help to achieve further clinical benefits.