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N ω -nitro- l -arginine methyl ester (L-NAME) is a non-specific nitric oxide (NO) synthase inhibitor, commonly used for the induction of NO-deficient hypertension. The objective of the present study was to investigate the effects of chrysin with flavnoids, on L-NAME-induced hypertensive rats. Methods: An experimental hypertensive animal (180–220 g) model was induced by L-NAME intake on rats. In treatment chrysin was orally administered 25 mg/kg body weight (b.w.). Blood pressure was measured by tail cuff plethysmography system. Cardiac and vascular function was evaluated by Langendorff isolated heart system with Angiotensin II (Ang-II), Hexo oxygenase (HO-1), cyclic guanosine monophosphate (cGMP) concentration in tissues respectively. Rats with hypertension showed an elevated blood pressure (BP), left ventricular functions, ang II, and decreased cGMP concentration of tissues. Treatment of chrysin is reverse to near normal in left ventricular functions, Ang-II, Ho-1 and decreased cGMP concentration of tissues. The antihypertensive effect of chrysin appears to be mediated by a reduction in left ventricular functions, cardiac oxidative stress and Ang-II, an increase in cardiac HO-1, cGMP concentration and a prevention of plasma nitric oxide loss.

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Objectives:To evaluate the effect of chrysin, a natural biologically active compound extracted from many plants, mushrooms, honey, and propolis on the tissue and circulatory antioxidant status and lipid peroxidation in N ω -nitro-L-ariginine methyl ester (L-NAME)-induced hypertensive rats. Materials and Methods: Hypertension was induced in adult male albino rats of the Wistar strain, weighing 180-220 g, by oral administration of l-NAME (40 mg/kg BWT/day) in drinking water for 4 weeks. Rats were treated with chrysin (25 mg/kg BWT/day) for 4 weeks. Results:The results showed significantly elevated levels of tissue malondialdehyde, protein carbonyl, and xanthine oxidase, and significantly lowered nonenzymatic antioxidant activity of glutathione reductase and glutathione-S-transferase in l-NAME-induced hypertensive rats compared with those in the control group. Supplementation of chrysin at the dosage of 25 mg/kg considerably decreased the levels of malondialdehyde, protein carbonyl, and xanthine oxidase and significantly increased the activities of glutathione reductase and glutathione-S-transferase in the tissues and blood compared with those in the unsupplemented l-NAMEinduced hypertensive groups. Conclusions: Chrysin offers protection against free radical-mediated oxidative stress in rats with l-NAME-induced hypertension.

Objectives:The study seeks to evaluate the effect of chrysin; a natural, biologically active compound extracted from plants, honey or propolis, on the tissues and circulatory antioxidant status and lipid peroxidation in N ω -nitro-l-arginine methyl ester (L-NAME) induced hypertensive rats. Materials and Methods: Male albino rats were divided into four groups. Control (Group I) and chrysin supplementation of the control (Group II) received normal diet. Groups III and IV received L-NAME (40 mg/kg B.W). Groups II and IV received chrysin (25 mg/kg B.W) dissolved in 0.2% dimethylsulfoxide solution after the 4 th week. Results and Discussion: The results showed significantly elevated levels of tissue and circulatory thiobarbituric acid reactive substances, conjugated dienes and lipid hydroperoxides, and significantly lowered enzymic and non-enzymic antioxidant activity of superoxide dismutase, catalase, glutathione peroxidase, reduced glutathione, vitamin C and vitamin E in L-NAME-induced hypertensive rats compared with those in control group. From chrysin administration to rats with L-NAME-induced hypertension leads to tissue damage which significantly decreases the levels of thiobarbituric acid reactive substances, lipid hydroperoxides and conjugated dienes, and significantly elevates the activity of superoxide dismutase, catalase, glutathione peroxidase, reduced glutathione, vitamin C and vitamin E in the tissues and circulation compared with those on the unsupplemented L-NAME induced hypertensive group. Conclusions: Chrysin offers protection against free radical-mediated oxidative stress in rats with L-NAME-induced hypertension.