Effect of Rice Bran Unsaponifiables on High-Fat Diet-Induced Obesity in Mice

Rice bran unsaponifiable matter (USM) was prepared by the saponification method and contained 1,635 mg of tocopherols and tocotrienols, 5,514 mg of policosanols, 36,425 mg of phytosterols, and 2,968 mg of oryzanols per 100 g of USM. Mice were divided into five groups: a normal diet (ND), high-fat diet (HFD), HFD with 10, 20 and 50 mg USM/kg body weight/day group. After 6 weeks, the administration of USM at doses of 10, 20 and 50 mg/kg reduced the body weight gain, food efficiency ratio and size of the epididymal fat tissue compared with those in the HFD group. In addition, the serum triglyceride, total cholesterol and low-density lipoprotein-cholesterol level as well as the atherogenic index and cardiac risk factor were also reduced in the USM fed groups compared with those in the HFD group. These findings suggest that USM from rice bran may have excellent hypolipidemic potential to prevent obesity. Practical Applications Rice bran unsaponifiable matter (USM) contains a variety of functional compounds. This study investigated the hypolipidemic effects of USM from rice bran in high-fat diet-fed mice. The result of this study suggested that rice bran USM was beneficial in preventing the development of hyperlipidemia. The use of rice bran USM may have implications for reducing the risk of cardiovascular disease.