Pathological pathway and protective mechanisms of phytobioactives used in diabetic retinopathy: A review

Diabetes mellitus (DM) is caused by either inadequate or dysfunctional insulin. It is one leading causes of Diabetic retinopathy (DR). Many synthetic medications have serious adverse effects that exacerbate the diabetic patient’s condition. The discovery of phytochemicals from medicinal plants offers a promising possibility for the creation of novel therapies for diabetes and its complications including DR. This review highlighted pathological mechanism of DR and also describe numerous plant-derived small compounds (phytochemicals) that have been studied in pre-clinical and clinical settings for their potential to have retinal cytoprotective effects. This also emphasise the mechanism retinal cryoprotection of phytochemicals. The sources were retrieved from various database such as Science Direct, Google Scholar, PubMed, Medline etc. In various studies, phytochemicals reduced inflammation, apoptosis pathways and oxidative stress, which inhibited the development of DR. Numerous phytochemicals, including flavonoids, lignan, glycosides, phytoestrogen etc., inhibited the production of Reactive Oxygen Species (ROS) and downregulation the inflammatory markers such as Interleukin-6(IL-6), Interleukin-1β(IL-1β), and Tumor necrosis factor-α (TNF-α). Overall most of the phytochemicals shows retinal cryoprotection by reducing generation of free radicals and inflammatory mediators.