Bacterial β-glucan exhibits potent hypoglycemic activity via decrease of serum lipids and adiposity, and increase of UCP mRNA expression

초록

This study was undertaken to evaluate the effect of bacteria-derived beta-glucan fiber on serum lipids, adiposity and uncoupling protein (UCP) expression in rats. In order to induce obesity, Sprague-Dawley weanling male rats were allowed free access to AIN-76A diet until 4 weeks of age, and fed high-fat diet (beef tallow, 40 % of calories as fat) for 6 weeks until 10 weeks of age. Rats were then fed with 0% (high-fat control group), 1%, or 5% bacterial beta-glucan supplemented high-fat diets (w/w) for another 6 weeks. For comparison, normal control group was fed with AIN-76 diet (11.7% fat). Supplementation with bacterial beta-glucan resulted in a significant reduction of high-fat-induced white fat (i.e., visceral and peritoneal fat) development, adipocyte hypertrophy, and development of hyperinsulinemia and hyperleptinemia. Serum triglyceride, total cholesterol, and free fatty acid levels were greatly reduced, but, HDL-cholesterol concentrations were increased by bacterial beta-glucan supplementation. Serum leptin level was lower in the beta-glucan groups than in the high-fat group. The expression of UCPs (UCP1, UCP2, and UCP3) in brown adipose tissue (BAT) were significantly increased by 5% bacterial beta-glucan-containing diet. This study suggests that the anti-obesity effect of 5% bacterial beta-glucan is attributed to upregulation of UCPs and inefficient energy utilization.

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