Cholesterol Lowering and Antioxidative Effect of Pregerminated Brown Rice in Hypercholesterolemic Rats

Pregerminated brown rice (GBR) is assumed to be more beneficial than polished white rice (WR), with regard to nutrition and cardiovascular health. To support this with scientific evidence, cholesterol-lowering and antioxidative effects of GBR were studied in the present investigation. The most popular rice variety in Bangladesh BIRI-29 was used to prepare GBR and WR. Initially, we analyzed the proximate composition, antioxidative phytochemicals, in vitro 2, 2-diphenyl-1-picrylhydrazyl (DPPH)-free radical scavenging ability and anti-hemolytic effects of GBR. To examine the dietary impact and possible benefits of the GBR, experimentally-induced hypercholesterolemic (HC, 1% cholesterol) rats were fed with GBR against WR for 12 wk. At the end, plasma total cholesterol (TC), low- and high-density lipoprotein-cholesterol (LDL-C and HDL-C), triglyceride (TG), fecal TC, and hepatic TC, lipid peroxide (LPO) and proinflammatory TNFα levels were determined. Relative to WR, GBR contained higher amounts of total polyphenols, total flavonoids, β-carotene and lycopene, and exhibited a stronger in vitro DPPH-free radical scavenging ability and antihemolytic potentials. Levels of plasma TC, LDL-C, TG, and hepatic TC and TG significantly decreased, while plasma HDL-C and fecal TC levels significantly increased in the GBR-fed HC-rats, indicating dietary GBR demonstrates a stronger antilipidemic effect than WR. The hepatic levels of LPO and TNFα also decreased (p<0.05) to a greater extent in GBR-fed HC-rats than those in the WR-fed rats. It is thus concluded that dietary GBR could be a natural treatment of hypercholesterolemia and related cardiovascular risk factors, and a source of antioxidants to reduce hemolysis and related anemia.