Evaluation of hypolipidemic, antioxidant, atherogenic index and cardiac risk suppressing effects of unpolished maniki madhuri rice extract and HPLC analysis of phenolics compounds

Abstract

Intake of whole grain has received huge consideration in recent times. This study aimed to investigate the hypolipidemic, antioxidant, and cardiac risk suppressing effect of whole rice extract of maniki madhuri joha rice (GI tagged) of Assam, India. In vitro antioxidant, HMG-CoA reductase enzyme inhibition assay, cholesterol esterase (CEase) inhibitory assay and antilipase activities of extracts of maniki madhuri were performed. Hyperlipidemia in experimental rats was induced by administering a high fat-high sugar diet for 45 days. Ethanol extract of whole rice (EtOH-MM) and atorvastatin were given orally to the animals in designated groups, and biochemical parameters were evaluated. Further, the presence of phenolic compounds was also estimated using the HPLC method. Extracts displayed concentration-dependent in vitro antioxidant, HMG-CoA reductase inhibitory and pancreatic lipase inhibitory activity. EtOH-MM exhibited strong CEase inhibitory activity (IC50 = 91.60 μg/ml). EtOH-MM at the dose of 200 and 400 mg/kg significantly ameliorated lipid parameters and the level of liver function marker enzymes to near normal. The lactate dehydrogenase and creatine kinase-NAC levels in EtOH-MM (400 mg/kg) group were 680.1 and 360.3 U/L, significantly less than the disease control group. C-reactive protein and lipoprotein a were significantly reduced in EtOH-MM treated group Ratio of ApoB/ApoA1 increased in the disease control group, which was reduced significantly in the standard and EtOH-MM treated group. The atherogenic index, atherogenic coefficient and cardiac risk ratio were decreased, while the cardioprotective index was increased in EtOH-MM treated group. Ten phenolic compounds i.e., gallic acid, caffeic acid, ferulic acid, p-coumaric acid, sinapic acid, o-coumaric acid, t-coumaric acid, rosamarinic acid, chlorogenic acid, phytic acid is quantified in maniki madhuri rice. The present study provided important evidence that consuming unpolished whole-grain of MM might be beneficial in managing hyperlipidemia and preventing associated cardiac complications.