Plant compounds in diabetic retinopathy therapy

Diabetic retinopathy (DR) is one of the most serious microvascular complications of diabetes and a leading cause of vision loss among adults worldwide. Current treatment methods, including anti-vascular endothelial growth factor (VEGF) injections and laser photocoagulation, though effective, are associated with high costs, limited availability, the need for frequent interventions, and potential side effects. These limitations underscore the need for alternative or adjunctive therapeutic strategies. In this context, plant-derived substances — such as curcumin, anthocyanins, resveratrol, carotenoids, and unsaturated fatty acids — have shown promising antioxidant, anti-inflammatory, antiangiogenic, and neuroprotective effects in preclinical studies. These compounds can modulate key pathological processes of DR, including oxidative stress, inflammation, and abnormal neovascularization. However, several challenges hinder their clinical implementation. Low bioavailability, poor water solubility, and rapid metabolism reduce their effectiveness, while the lack of standardization in plant extracts complicates the evaluation of safety and efficacy.