ABSTRACT
The aim of this study was to investigate the effect of antioxidant vitamin C and E either alone or in combination and also the effect of melatonin on the blood glucose, insulin, C peptide and lipids in streptozotocin diabetic rats. Sixty male albino rats were divided into six equal groups; one served as a control, rats in the other groups were rendered diabetic by a single intraperitoneal injection of 30 mg/kg body weight streptozotocin [STZ] and were divided into five equal groups, one remained diabetic without antioxidants, while the other four groups were given daily an oral supplementation of vitamin C, vitamin E, combined treatment of vitamin C and E and melatonin, respectively. The current study implied that melatonin and a combination therapy of vitamin C and E induced the most beneficial effect in STZ diabetic rats, especially in a pattern of changes in the total cholesterol and lipoprotein metabolism that are related to the increased risk of atherosclerosis