Protective Effect of Melatonin in the Diabetic Elderly Female Rats Retinal

This study was designed to evaluate the efficacy of melatonin against streptozotocin (STZ)‐induced changes in rat retina following the development of diabetes. The study was performed on elderly female rats (16 months) obtained from Selçuk University Experimental Medicine Research and Application Center. The ethics committee of the same center approved the study. A total of 24 elderly female rats were divided into 4 groups. Group 1. Control, Group 2. Control + Melatonin Group 3. Diabetes, Group 4. Diabetes + Melatonin. Experimental diabetes was induced to Group 3 and group 4 by a single intraperitoneal injection of Streptozotocin (STZ) “Sigma, S-0130" (50 mg/kg). 6 days after the STZ injection, blood was collected from the tip of the tail vein of the animals and blood glucose were measured by a diagnostic glucose kit. The rats having hyperglycemia (≥300 mg/ dl) were assigned as diabetic. After 4-weeks melatonin treatment period, MDA ve GSH levels were determined by ELISA, on retinal tissue samples obtained from the animals sacrificed under general anesthesia. In our study, the highest retinal MDA values were obtained in the diabetes group (G3) (P <0.05). The highest retinal GSH values were obtained in the Diabetes + Melatonin group (G4) (P <0.05). The results of the present study revealed that retinal oxidative stress can be prevented by melatonin supplementation in diabetic elderly female rats. It can be concluded that melatonin might has beneficial effects in prevention of diabetic retinopathy