Anti-hyperlipidemic activity of oryzanol, isolated from crude rice bran oil, on Triton WR-1339-induced acute hyperlipidemia in rats

Abstract

Experimental studies carried out for evaluating the anti-hyperlipidemic properties of rice bran components have given interesting but often contrasting results. Therefore, the current study was initiated to investigate the anti-hyperlipidemic activity of oryzanol (OZ), a commercially-important bioactive phytochemical, isolated from crude rice bran oil (cRBO). OZ was isolated by a two-step solvent crystallization process from cRBO, which was extracted from fresh rice bran by hexane mediated soxhlet extraction. Subsequently, OZ (50 and 100 mg/kg, p.o.) was evaluated for anti-hyperlipidemic activity in Triton WR-1339-induced acute hyperlipidemic albino rats by estimating serum triacylglyceride (TG), total cholesterol (TC), very low density lipoproteincholesterol (VLDL-C), low-density lipoprotein-cholesterol (LDL-C) and high-density lipoprotein-cholesterol (HDL-C) levels with atorvastatin as the reference standard. The degree of protection was also assessed by measuring the levels of various hepatic antioxidant enzymes. OZ evoked a signifi cant decrease in the levels of serum cholesterol, triacylglycerides, LDL, VLDL and a signifi cant increase in the level of serum HDL and hepatic anti-oxidant enzymes. It also showed a signifi cant ameliorative action on elevated atherogenic index (AI) and LDL/HDL-C ratios. These fi ndings indicate that OZ possesses the potential to lower plasma lipid concentrations and might be of therapeutic benefi t in hyperlipidemia and atherosclerosis.

By-products of Rice Processing: An Overview of Health Benefits and Applications

“…In addition to those preliminary studies, other research has shown that there is a significant effect of these rice branderived products on improving the lipid profile (Table 6). However, black rice bran extracts reduce the progression of dietary cholesterolinduced atherosclerotic plaque development and cholesterol plasma levels in rabbits [125,126] while decreasing the levels of serum triglycerides and total cholesterol in mice [127].…”

Rice Bran Oil

“…In addition, a significant increase in the level of hepatic antioxidant enzymes showed a high degree of hepatic protection against free radicals. 38 γ-Oryzanol exerts a hypolipidemic effect even when blended with other vegetable oils. Rats fed a diet containing blends of refined groundnut oil having 3%, 5%, or 10% of γ-oryzanol showed a decrease in total cholesterol in serum (7-16%) and in liver (15%), depending on the γ-oryzanol concentration used, when compared to cholesterol levels of the rats fed on pure groundnut oil.…”

Protective effect of oryzanol isolated from crude rice bran oil in experimental model of diabetic neuropathy

“…The isolation of OZ from cRBO using a modified two-step crystallization process previously described by Zullaikah et al (2009) has been discussed previously (Ghatak & Panchal, 2012a). The isolated OZ was identified with respect to the standard by melting point determination, thin-layer chromatography (TLC), UV-visible spectrophotometry and high-performance liquid chromatography (HPLC), the results of which have been published recently (Ghatak & Panchal, 2012b).…”