Veratric acid, a phenolic acid attenuates blood pressure and oxidative stress in l-NAME induced hypertensive rats

The present study was undertaken to assess the antihypertensive and antioxidant effects of veratric acid on Nω-nitro-L arginine methyl ester (l-NAME) induced hypertensive rats. Hypertension was induced in adult male albino rats of the Wistar strain, weighing 180-220 g, by oral administration of the l-NAME (40 mg/kg body weight/day) in drinking water for 4 weeks. Rats were treated with various doses of veratric acid (20, 40, 80 mg/kg/day) for four weeks. Hypertension was manifested by considerably increased systolic and diastolic blood pressure and the toxic effect of l-NAME was determined using lipid peroxidative markers (thiobarbituric acid reactive substances and lipid hydroperoxides). We also assessed the activities of enzymatic antioxidants (superoxide dismutase, catalase, and glutathione peroxidase) and measured the levels of non-enzymatic antioxidants (vitamin-C, vitamin-E and reduced glutathione) levels in erythrocytes, plasma and tissues and plasma nitric oxide metabolites (nitrite/nitrate). Oral administration of veratric acid at the dosage of 40 mg/kg considerably decreased systolic and diastolic blood pressure, lipid peroxidation products; increased plasma nitric oxide levels and showed no toxicity which was measured using hepatic and renal function markers when compared to other doses of veratric acid (20, 80 mg/kg). In addition, histopathological findings of veratric acid treated hypertensive rat heart confirmed the biochemical findings of this study. These results suggest that veratric acid decreased the blood pressure, significantly restored nitric oxide, enzymatic and non-enzymatic antioxidants and reduced lipid peroxidation products and thus exhibits antihypertensive and antioxidant effects against l-NAME induced hypertension.