Abstract
Diabetic retinopathy (DR), one of the most common complications of diabetes, is the leading cause of legal blindness among adults of working age in developed countries. After 20 years of diabetes, almost all patients suffering from type I diabetes mellitus and about 60% of type II diabetics have DR. Several studies have tried to identify drugs and therapies to treat DR though little attention has been given to flavonoids, one type of polyphenols, which can be found in high levels mainly in fruits and vegetables, but also in other foods such as grains, cocoa, green tea or even in red wine. Flavonoids have anti-inflammatory, antioxidant and antiviral effects. Since it is known that diabetes induces oxidative stress and inflammation in the retina leading to neuronal death in the early stages of the disease, the use of these compounds can prove to be beneficial in the prevention or treatment of DR. In this review, we summarize the molecular and cellular effects of flavonoids in the diabetic retina.
Highlights
Diabetes and Diabetic RetinopathyDiabetes mellitus is a group of metabolic diseases characterized by chronic hyperglycemia resulting from defects in insulin secretion, insulin action or both, leading to various serious damaging consequences such as heart attacks, blindness, kidney failure, leg amputation and stroke
It was observed that a reduction of the inflammatory and oxidative environment, caused by a decrease in pro-oxidant enzymes endothelial nitric oxide synthase and NADPH oxidase 4 (Nox4), increased antioxidant enzymes catalase (CAT) and superoxide dismutase (SOD), and inhibition of the intercellular adhesion molecule-1 (ICAM-1) and nuclear factor-κB (NF-κB) pathway
As shown by several studies performed in vivo, using animal models of diabetes, and in vitro, using different cell cultures, flavonoids can prevent the disruption of the blood–retinal barrier (BRB), decrease the release of proinflammatory mediators, improve the oxidative state and prevent the reduction in retina thickness by attenuating apoptosis and neurodegeneration
Summary
Diabetes mellitus is a group of metabolic diseases characterized by chronic hyperglycemia resulting from defects in insulin secretion, insulin action or both, leading to various serious damaging consequences such as heart attacks, blindness, kidney failure, leg amputation and stroke. There are significant differences between various regions of the globe, a recent study calculates the global prevalence of DR at 27% [2]. This means that of the 463 million diabetic adults as of 2019, 125 million have DR. Modifiable risk factors associated with DR include obesity, smoking, hyperglycemia, hypertension and dyslipidemia [7,9]. All these factors contribute to the development of diabetes and increase the risk of DR. Cataract surgery in diabetic patients who do not have DR increases the risk of developing non-proliferative DR (NPDR) when receiving the surgery [10]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
