Protective effect of melatonin in the diabetic rat retina

Abstract

Diabetic retinopathy (DR) is one of the most common and serious microvascular complications of diabetes. The aim of this study was to evaluate the effects of melatonin (MEL) on retinal injury in diabetic rats. In this study, 21 rats were randomly divided into three groups: control, diabetic, and diabetic + MEL. Streptozotocin was used to induce diabetes at a dose of 50 mg/kg, i.p., and blood glucose was measured to choose the diabetic rats for the study. MEL (20 mg/kg) was given orally for 7 weeks in diabetic rats starting 1 week after induction of diabetes. After 8 weeks, the groups were compared in terms of mean scores of fluorescein leakage, using fluorescein angiography. Reactive oxygen species (ROS) and malondialdehyde (MDA) levels were estimated in retina using commercially available assays. Structural changes in retinas were evaluated by light microscopy. Results showed that diabetes significantly increased the mean scores of fluorescein leakage, and MDA and ROS levels compared to control group. Treatment of the diabetic rats with MEL for 7 weeks prevented the alterations induced by diabetes in comparison with the diabetic control group.Based on these findings, it can be concluded that MEL might have beneficial effects in prevention of DR.

Ursodeoxycholic acid suppresses the formation of fructose/streptozotocin‐induced diabetic cataract in rats

“…These results substantiate the hypothesis that oxidative stress may be the predominant mechanism in FR‐/STZ‐induced diabetic cataract. Similar findings have been previously reported in diabetic cataract and retinopathy induced by high glucose‐feeding or STZ administration . In addition, a decrease in T‐AOC along with high levels of lipid peroxidation has also been demonstrated in vitreous, aqueous humor and blood samples from patients with diabetic retinopathy .…”

Melatonin: new insights on its therapeutic properties in diabetic complications

“…Melatonin treatment triggers Akt-Nrf2-induced antioxidant system and suppresses NF-κB pathway; it is suggested that regulating retinal melatonin and its receptors could be a beneficial method for treatment of diabetic retinopathy [106]. Melatonin reduces the mean scores of fluorescein leakage and the level of ROS and malondialdehyde (MDA) as well as suppresses the apoptosis and inflammation in rats with diabetic retinopathy through repressing the MAPK pathway [107,108].…”

Update on the Effects of Antioxidants on Diabetic Retinopathy: In Vitro Experiments, Animal Studies and Clinical Trials

“…There is an increasing body of evidence about the role of antioxidants in the control of diabetic retinopathy in animal models ( Table 2 ) [ 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 , 87 , 88 , 89 , 90 , 91 , 92 , 93 , 94 , 95 , 96 , 97 , 98 , 99 , 100 , 101 , …”