The effect of Plant by-products on liver functions and plasma glucose in rats fed a high fat diet induced obesity.

Abstract We have examined the metabolic effects of daily administration of carbenoxolone (CBX), a naturally occurring 11β-hydroxysteroid dehydrogenase (11β-HSD1) inhibitor, in mice with high fat diet-induced insulin resistance and obesity. Eight-week-old male Swiss TO mice placed on a synthetic high fat diet received daily intraperitoneal injections of either saline vehicle or CBX over a 16-day period. Daily administration of CBX had no effect on food intake, but significantly lowered body weight (1.1- to 1.2-fold) compared to saline-treated controls. Non-fasting plasma glucose levels were significantly decreased (1.6-fold) by CBX treatment on day 4 and remained lower throughout the treatment period. Circulating plasma corticosterone levels were not significantly altered by CBX treatment. Plasma glucose concentrations of CBX-treated mice were significantly reduced (1.4-fold) following an intraperitoneal glucose load compared with saline controls. Similarly, after 16-day treatment with CBX, exogenous insulin evoked a significantly greater reduction in glucose concentrations (1.4- to 1.8-fold). 11β-HSD1 gene expression was significantly down-regulated in liver, whereas glucocorticoid receptor gene expression was increased in both liver and adipose tissue following CBX treatment. The reduced body weight and improved metabolic control in mice with high fat diet-induced obesity upon daily CBX administration highlights the potential value of selective 11β-HSD1 inhibition as a new route for the treatment of type 2 diabetes and obesity.

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

International Journal for Vitamin and Nutrition Research ◽

10.1024/0300-9831.79.4.255 ◽

2009 ◽

Vol 79 (4) ◽

pp. 255-263 ◽

Cited By ~ 15

Author(s):

XiuHua Shen ◽

QingYa Tang ◽

Jiang Wu ◽

Yi Feng ◽

Juan Huang ◽

...

Keyword(s):

Oxidative Stress ◽

Vitamin E ◽

Glucose Metabolism ◽

Plasma Glucose ◽

High Fat Diet ◽

Intervention Group ◽

Male Rats ◽

Control Group ◽

High Fat ◽

Diet Induced Obesity

Objective: To evaluate the effect of vitamin E on the level of oxidative stress in diet-induced obese Sprague-Dawley rats. Methods: 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- F2α (8-epi-PGF2α), thiobarbituric acid-reactive substances (TBARS), total anti-oxidative capacity (TAOC), α-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. Results: After 10 weeks, all obese rats (both the DIO and VE groups) had higher plasma 8-epi-PGF2α and TBARS levels than the controls. Their plasma-adjusted α-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-PGF2α (p<0.05). VE intervention also decreased plasma glucose, insulin, and TG levels (p<0.05). Conclusions: 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.

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