Submitted to: Nutrition Research
Publication Type: Peer reviewed journal
Publication Acceptance Date: 8/13/2004
Publication Date: 9/24/2004
Citation: Seo, J.S., Lee, K.S., Jang, J.H., Zhejiu, Q., Yang, K.M., Burri, B.J. The effect of dietary supplementation of b-carotene on lipid metabolism in streptozotocin-induced diabetic rats. Nutrition Research 24 1011-1021, 2004. Interpretive Summary: Diabeties Mellitu is associated with increased risk for heart disease. We investigated the effectiveness of B-carotene in preventing the vacular complications of diabeties in rats. We found that B-carotene supplementation did not reduce blood glucose, but it did reduce total triglycerides. Additionally, B-carotene decrease the atherogenic index of these diabetic rats. Finally, B-carotene feeding tended to increase the excretion of cholesteroll and coprostanone, but not significantly. Our results suggest that B-carotene supplements may decrease the incidence of diabetic vascular complications, thus potentially decreasing the risk for heart disease.
Technical Abstract: Diabetic vascular complications such as atherosclerosis complicate the treatment of diabetes. We hypothesized that moderate supplementation with B-carotene might help prevent diabetic vascular complications through its impact on cholesterol metabolism. Forty Sprague-Dawley rats were fed AIN-76 control diet, or the same diet supplemented with 7.2 mg/kg diet B-carotene for three weeks, then diabetes was induced in half of the rats by streptozotocin. Diabetic and normal rats were fed the experimental diets for two more weeks. B-carotene did not reduce blood glucose in diabetic rats. Plasma triglycerides were increased by diabetes, but reduced by B-carotene. Total- and LDL-cholesterol were increased by diabetes. HDL-cholesterol did not differ between groups. B-carotene reduced cholesterol levels, but decreases were not significant. However, the atherogenic index of diabetic rats was higher than that of control rats, and B-carotene feeding decreased it. Fecal excretion of cholesterol and coprostanone were decreased by diabetes, and B-carotene tended to increase this excretion. Fecal excretion of bile acid showed similar tendencies, as did neutral steroids. These results suggest that dietary supplementation with B-carotene may reduce plasma triglycerides and other indices of diabetic risk, and thus may decrease the incidence of diabetic vascular complications through the normalization of lipid metabolism in diabetics.