Effect of Mamao Pomace on the Reduction of Blood Pressure in L-NAME- Induced Hypertensive Rats

Abstract

Background and Objective: Mamao juice and wine are the commercial products produced from mamao fruits.  It has been demonstrated that mamao pomace (MP), a by-product generated from mamao fruits, contains a large amount of antioxidant polyphenolic compounds. Hypertension is one of the major risk factors of cardiovascular disease (CVD) and its development has a close link with oxidative stress. The aim of this study was to evaluate whether MP could protect against N(G)-Nitro-L-arginine-methyl ester (L-NAME)-induced hypertension and oxidative stress in rats.

Methods: Male Sprague–Dawley rats were administered with L-NAME (a nitric oxide synthase inhibitor) at a dose of 50 mg/kg/day in drinking water for three weeks. MP (100 mg/kg) was administered once daily to animals simultaneously with L-NAME. Rats in normal control group served as normotensive animals.

Results: Marked increases in blood pressure, peripheral vascular resistance, and oxidative stress were found in rats after L-NAME administration. MP significantly reduced these deleterious effects, by reducing blood pressure and improving hemodynamic status concomitant with reduction in vascular superoxide (O₂^·-) production when compared with L-NAME control group (p<0.05).

Conclusion: The present study suggests that MP might be used as a dietary supplement to protect against hypertension and oxidative stress in NO (nitric oxide) deficient condition.

Key words: Mamao pomace, hypertension, oxidative stress