Arginase Enzyme Inhibition and with Subsequent Atheroprotection of Butanol Fraction of Rivea ornata in Lipid Emulsion Induced Atherosclerosis in Rats
Objectives: 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 current study was wanted to explore the atheroprotective effect of polyphenolic fraction of Rivea ornata by using lipid emulsion induced atherosclerosis in rat model. Materials and Methods: 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. Results: 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 HDL, paraoxonase, nitric oxide, tissue thiol levels, endogenous antioxidants and decreases TG, TC, VLDL, LDL myeloperoxidase, arginase, hydroxyproline, lipid peroxidation. And atheroprotection reflected in histopathology studies also. Lipid emulsion associated foam cells formation is inhibited by butanol fraction. Conclusion: This is all due to presence of gallic acid in polyphenol rich butanol fraction is responsible for the underlying mechanism of atheroprotection.