Retinoprotective Effects of Moringa oleifera via Antioxidant, Anti-Inflammatory, and Anti-Angiogenic Mechanisms in Streptozotocin-Induced Diabetic Rats

Purpose: The present study was aimed to evaluate the retinoprotective effects of Moringa oleifera (MO) in Streptozotocin-induced diabetic rats. Methods: The study was continued for 24 weeks and evaluated for inflammatory (tumor necrosis factor [TNF]-alpha and interleukin [IL]-1 beta, angiogenic (vascular endothelial growth factor [VEGF] and protein kinase C [PKC]-beta) and antioxidant (Glutathione, Superoxide dismutase, and Catalase) parameters. Retinal leakage was checked by Fluorescein angiography (FA) and fundus photographs were evaluated for retinal vessel caliber (arteriolar and venular). Transmission electron microscopy was done to determine basement membrane (BM) thickness. Results: The results of the present study showed potential hypoglycemic and retinal antioxidant effects of MO. In the present study, a significant rise in the expression of retinal inflammatory (TNF-alpha and IL-1 beta) and angiogenic (VEGF and PKC-beta) parameters was observed in diabetic retinae as compared to normal retinae. However, MO-treated retinae showed marked inhibition in the expression of inflammatory and angiogenic parameters. Further, in the present study, diabetic retinae showed dilated retinal vessels as compared to normal. However, MO-treated retinae showed marked prevention in the dilatation of retinal vessels. Fluorescein angiograms obtained from diabetic retinae showed leaky and diffused retinal vasculature. On the other hand, MO-treated retinae showed intact retinal vasculature. Further, results of the transmission electron microscopy study showed thickened capillary BM in the diabetic retina as compared to normal retinae. However, treatment with MO prevented thickening of capillary BM. Conclusion: Our result suggests that MO may be useful in preventing diabetes induced retinal dysfunction.