Roles of Reactive Oxygen Species in Vascular Complications of Diabetes: Therapeutic Properties of Medicinal Plants and Food

The rising prevalence of chronic metabolic disorders, such as obesity and type 2 diabetes, most notably associated with cardiovascular diseases, has emerged as a major global health concern. Reactive oxygen species (ROS) play physiological functions by maintaining normal cellular redox signaling. By contrast, a disturbed balance occurring between ROS production and detoxification of reactive intermediates results in excessive oxidative stress. Oxidative stress is a critical mediator of endothelial dysfunction in obesity and diabetes. Under a hyperglycemic condition, the antioxidant enzymes are downregulated, resulting in an increased generation of ROS. Increases in ROS lead to impairment of endothelium-dependent vasodilatations by reducing NO bioavailability. Chronic treatments with antioxidants were reported to prevent the development of endothelial dysfunction in diabetic patients and animals; however, the beneficial effects of antioxidant treatment in combating vascular complications in diabetes remain controversial as antioxidants do not always reverse endothelial dysfunction in clinical settings. In this review, we summarize the latest progress in research focused on the role of ROS in vascular complications of diabetes and the antioxidant properties of bioactive compounds from medicinal plants and food in animal experiments and clinical studies to provide insights for the development of therapeutic strategies.