Anti-Obesity Effect of Rice Bran Extract on High-Fat Diet-Induced Obese Mice

Obesity involving adipose tissue growth and development are associated with angiogenesis and extracellular matrix remodeling. Rice bran has antioxidant and cardioprotective properties, and can act as a food supplement with potential health benefits, such as lowering blood pressure, hepatic steatosis, and inflammation. Therefore, we hypothesized that rice bran extract (RBE) can regulate adipose tissue growth and obesity. Male Institute of Cancer Research mice were fed with a high-fat diet (HFD) for 8 weeks and then supplemented with 220 and 1,100 mg/kg/d RBE while the low-fat diet group (control) were not. In addition to body weight, adipose tissue mass, and vessel density, we evaluated the mRNA expression of angiogenic factors such as matrix metalloproteinases, Mmp-2, Mmp-9, and the vascular endothelial growth factor (Vegf) in visceral and subcutaneous adipose tissues using real-time polymerase chain reaction. Administration of RBE to HFD-induced obese mice reduced the body weight and adipose tissue mass compared with untreated mice. It also decreased blood vessel density in the adipose tissue. Furthermore, RBE downregulated Vegf and Mmp-2 mRNA levels in visceral fat tissue. These results demonstrate that RBE, at high concentrations, significantly reduces adipose tissue mass and prevents obesity development in HFD-induced obese mice, which might be partly mediated via an anti-angiogenic mechanism.