Black rice (Oryza sativa L.) reduces obesity and improves lipid metabolism in C57BL/6J mice fed a high-fat diet

Abstract To investigate the effects of dietary supplementation of WGBR on lipid metabolism, C57BL/6J mice were fed a normal chow diet, a high-fat diet based on corn starch, a high-fat diet based on white rice, and low or high dosage of black rice for 12 weeks. WGBR alleviated high-fat diet-induced increase in body weight and visceral weight; reduced serum TC, TG, and non-HDL-C/HDL-C levels; and increased fecal sterols and fat excretion. Furthermore, WGBR decreased hepatic TG and TC contents through the pathway of AMPK. This, in turn, decreased PPARγ, SREBP-1c, FASN, ACC, and HMGCOR-A and increased LXRα, PPARα, and CPT1α at the gene level. Further, it lowered PPARγ and elevated PPARα, p-ACC/ACC, and p-AMPKα/AMPKα at the protein level. Additionally, WGBR treatment decreased gene expression of NPC1L1, ACAT2, MTTP, which regulated lipid absorption in the intestine and preserved CYP7A1, ABCG5/8 that transported cholesterol from the liver and enterocytes to the intestinal lumen.