Butanol Fraction of <i>Rivea ornata</i> Attenuate Endothelial Dysfunction in Rats via Modulation of Cardiovascular Risk Factors

Abstract

Atherosclerosis is caused by vascular inflammation and oxidative stress. Pro-atherogenic effect of hypercholesterolemia caused by impairment of nitric oxide generation due to activated arginase. The study takes up to find the atheroprotective role of polyphenolic fraction of <em>Rivea ornata</em> leaves by using lipid emulsion induced atherosclerosis in rat model. The study carried out by studying atherogenic markers in the serum (lipid profiles, C-reactive protein), vascular tissue (myeloperoxidase, arginase, hydroxyproline, lipid peroxidation) and atheroprotective factors in the serum (paraoxonase, nitric oxide), and in the vascular tissue (thiol levels, endogenous antioxidants) after feeding the rats with lipid emulsion for 12 weeks. Treatment of polyphenolic rich butanol fraction is able to correct the imbalance of atherogenic and antiatherogenic factors induced by lipid emulsion feeding. Butanol fraction at the dose of 400 mg/kg significantly increases high density lipoprotein, paraoxonase, nitric oxide, tissue thiol levels, endogenous antioxidants and decreases total triglycerides, total cholesterol, very low-density lipoprotein, low density lipoprotein, myeloperoxidase, arginase, hydroxyproline, lipid peroxidation. The atheroprotection reflected in histopathology studies also. Lipid emulsion associated foam cells formation is inhibited by butanol fraction. These all are due to the presence of gallic acid in polyphenol rich butanol fraction is responsible for the underlying mechanism of atheroprotection.