Effect of Vitamin E Supplementation on Oxidative Stress in a Rat Model of Diet-induced Obesity

Abstract

To evaluate the effect of vitamin E on the level of oxidative stress in diet-induced obese Sprague-Dawley rats. Thirty weaning male rats were placed into three groups with 10 animals each: a control group with normal chow, a diet-induced obesity group (DIO) with high-fat diet, and an intervention group with high-fat diet supplemented with vitamin E (VE, 350 mg/kg). Blood and adipose tissue were collected from rats after 10 weeks. Biomarkers of oxidative stress were detected for plasma 8-epi-prostaglandin- F(2)alpha (8-epi-PGF(2)alpha), thiobarbituric acid-reactive substances (TBARS), total anti-oxidative capacity (TAOC), alpha-tocopherol, superoxide dismutase (SOD) activity, and glutathione peroxidase activity (GPx). Lipid and glucose metabolism parameters such as plasma glucose, insulin, and triacylglycerol (TG) were also analyzed. After 10 weeks, all obese rats (both the DIO and VE groups) had higher plasma 8-epi-PGF(2alpha) and TBARS levels than the controls. Their plasma-adjusted alpha-tocopherol, SOD, and GPx activities were lower than the control levels but insulin was higher (p<0.01). The VE intervention increased plasma SOD, GPx, and T-AOC, and decreased 8-epi-PGF(2alpha) (p<0.05). VE intervention also decreased plasma glucose, insulin, and TG levels (p<0.05). Increased oxidative stress could be an important target for the prevention of obesity-related diseases. Vitamin E has moderate effects for improvement of oxidative stress status and glucose metabolism in the animal model of diet-induced obesity.