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Background and Objective: Hypertension is the important risk factor for cardiovascular disease (CVD). Oxidative stress is associated with the development of hypertension. Consumption of dietary antioxidants appears to decrease blood pressure, improve endothelial function and reduce the risk of CVD. Whole grain essential oil (WEO) possesses strong antioxidant property and has been reported to reduce the CVD risk. This study aimed to evaluate the antihypertensive property of WEO using a rat model of nitric oxide (NO) deficiency hypertension.
Methods: Male Sprague-Dawley rats received a nitric oxide synthase (NOS) inhibitor, Nω-nitro-L-arginine methyl ester (L-NAME) at dose of 50 mg/kg/day in drinking water for 3 weeks. WEO (1 or 2 ml/kg/day) were intragastrically administered during L-NAME administration.
Results: A markedly increased arterial blood pressure, elevated hindlimb vascular resistance and decreased hindlimb blood flow were found in L-NAME-induced hypertensive rats (p < 0.05). Enhanced vascular superoxide production, increased oxidative stress and decreased NO metabolites (NOx) levels were also found in L-NAME-treated rats. Concurrent treatment with WEO resulted in a dose-dependent improved hemodynamic status and significantly reversed the L-NAME-induced oxidative stress and suppression of NO production (p < 0.05).
Conclusions: The data revealed that WEO is an effective antioxidant that helps to reduce high blood pressure. The antihypertensive effects of WEO are likely to be mediated by increasing antioxidant activities and restoring NO bioavailability.
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