The relationship between melatonin level and antioxidant enzymes in diabetic patients with and without nephropathy

Abstract

Background and objective: Diabetes is the most common cause of chronic renal disease globally. Diabetic nephropathy (DN) is one of the most serious consequences of type 2 diabetes. Melatonin, a powerful antioxidant that has been shown to alleviate DN, deficiency and a functional relationship between melatonin and insulin have been linked to the etiology of type 2 diabetes mellitus. The purpose of this research is to assess the relationship between melatonin level and antioxidant enzyme activity (catalase, glutathione peroxidase, superoxide dismutase, paraoxonase 1, and glutathione-s-transferase) in diabetic patients with and without nephropathy. Methods: This case-control study was conducted on 45 healthy control subjects, 45 diabetic patients without nephropathy, and 45 diabetic patients with nephropathy. Serum samples of participants were used to evaluate antioxidant enzyme activities, melatonin levels, and MDA using specific assays. Results: The results showed that the concentration of melatonin is not affected in diabetic patients without nephropathy, but decreased significantly in diabetic patients with nephropathy when compared with healthy subjects. Antioxidant enzymes activity in sera of diabetic patients with and without nephropathy were significantly lower than that of healthy subject group. The superoxide dismutase enzyme has a specific exception because its activity is elevated, unlike other antioxidant enzymes. Conclusions: Melatonin decreased significantly in sera of diabetic patients with nephropathy. Diabetic nephropathy affects antioxidant enzymes activity and lipid peroxidation significantly compared with healthy controls.