Effect of vitamin e and selenium supplement on paraoxonase-1 activity, oxidized low density lipoprotein and antioxidant defense in diabetic rats

Introduction: The aim of the present study was to assess the effects of vitamin E and selenium supplementation on serum paraoxonase (PON1) activity, lipid peroxidation and antioxidant defense in streptozotocin-induced diabetic rats.

Methods: Thirty two female Sprague Dawley rats were divided into 3 groups: the control group (n=8) received a standard diet; streptozotocin (STZ)-induced diabetic rats (n=12), received corn oil and physiological solution; and vitamin E and selenium supplemented diabetic rats (n=12) were treated with oral administration of vitamin E (300 mg/kg) and sodium selenite (0.5 mg/kg) once a day for 4 weeks.

Results: Significantly lower total antioxidant status (TAS), PON1and erythrocyte SOD activities and a higher fasting plasma glucose level were observed in the diabetic rats compared to the control. A significant increase in SOD and GPX activities in vitamin E and selenium supplemented diabetic group was observed after 5 weeks of the experiment. Compared to the normal rats, malondialdehyde (MDA) and oxidized LDL (Ox-LDL) levels were higher in the diabetic animals; however, these values reduced significantly following vitamin E and selenium supplementation.

Conclusion: Vitamin E and selenium supplementation in diabetic rats has hypolipidemic, hypoglycemic and antioxidative effects and may slow down the progression of diabetic complications through its protective effect on PON1 activity and lipoproteins oxidation.