Sorghum extract exerts an anti-diabetic effect by improving insulin sensitivity via PPAR-gamma in mice fed a high-fat diet

ABSTRACT

This study investigated the hypothesis that a sorghum extract exerts anti-diabetic effects through a mechanism that improves insulin sensitivity via peroxisome proliferator-activated receptor gamma (PPAR-gamma) from adipose tissue. Seven C57BL/6 mice were fed an AIN-93M diet with fat consisting of 10% of total energy intake (LF) for 14 weeks, and 21 mice were fed a high-fat AIN diet with 60% of calories derived from fat (HF). From week 8, the HF diet-fed mice were orally administered either saline (HF group), 0.5% (0.5% SE group), or 1% sorghum extract (1% SE group) for 6 weeks (n = 7/group). Perirenal fat content was significantly lower in the 0.5% SE and 1% SE groups than that in the HF mice. Levels of total and low-density lipoprotein cholesterol, triglycerides, glucose, and the area under the curve for glucose were significantly lower in mice administered 0.5% SE and 1% SE than those in HF mice. Serum insulin level was significantly lower in mice administered 1% SE than that in HF mice or those given 0.5% SE. PPAR-gamma expression was significantly higher, whereas the expression of tumor necrosis factor-alpha was significantly lower in mice given 1% SE compared to those in the HF mice. Adiponectin expression was also significantly higher in mice given 0.5% SE and 1% SE than that in the HF mice. These results suggest that the hypoglycemic effect of SE may be related with the regulation of PPAR-gamma-mediated metabolism in this mouse model.