Direk Aekthammarat1, Patchareewan Pannangpetch1, Panot Tangsucharit2. 1. Department of Pharmacology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand; Cardiovascular Research Group, Khon Kaen University, Khon Kaen 40002, Thailand. 2. Department of Pharmacology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand; Cardiovascular Research Group, Khon Kaen University, Khon Kaen 40002, Thailand. Electronic address: pantan@kku.ac.th.
Abstract
BACKGROUND: Enhancing relaxation of resistance arteries and decreasing oxidative stress by using natural products are potential strategies for prevention and treatment of hypertension. PURPOSE: This study investigated whether aqueous extract of Moringa oleifera leaves (MOE) could alleviate Nω-nitro-L-arginine-methyl ester (L-NAME)-induced high blood pressure via modulation of vascular function and antioxidant properties. METHODS: An experimental hypertensive model was established by administration of L-NAME (50 mg/kg/day) in drinking water to male Wistar rats for 3 weeks. Arterial pressure was measured indirectly by tail-cuff plethysmography and directly via femoral artery catheterization. Vasoreactivity of isolated rat mesenteric arterial bed was determined by the changes in perfusion pressure detected by a pressure transducer. Vascular superoxide anion (O2•-) production was determined by lucigenin-enhanced chemiluminescence. Other biochemical measurements including malondialdehyde (MDA) level, superoxide dismutase (SOD), and catalase (CAT) activities were measured by colorimetric assay. RESULTS: L-NAME-treated rats developed significantly increased blood pressure and heart rate. Concurrent oral treatment with MOE (30 and 60 mg/kg/day) could decrease the high blood pressure and tachycardia in a dose-dependent manner. MOE reduced the impairment of acetylcholine-induced relaxation and decreased the hyperreactivity of adrenergic-mediated contraction in response to periarterial nerve stimulation and phenylephrine in isolated mesenteric arterial beds. In addition, MOE exhibited antioxidant effects in the hypertensive rats, as indicated by suppression of vascular O2•- production, decrease of plasma and thoracic aorta MDA levels, and increase of antioxidant activities of SOD and CAT. Moreover, MOE (0.001-0.3 mg) produced a dose-dependent relaxation in methoxamine pre-contracted arterial beds isolated from L-NAME hypertensive rats, which was abolished by endothelium denudation. CONCLUSION: These findings suggest that the antihypertensive effect of MOE in L-NAME-hypertensive rats may be mediated by alleviating vascular dysfunction and oxidative stress and promoting endothelium-dependent vasorelaxation. MOE may be potentially useful as a natural product against hypertension.
BACKGROUND: Enhancing relaxation of resistance arteries and decreasing oxidative stress by using natural products are potential strategies for prevention and treatment of hypertension. PURPOSE: This study investigated whether aqueous extract of Moringa oleifera leaves (MOE) could alleviate Nω-nitro-L-arginine-methyl ester (L-NAME)-induced high blood pressure via modulation of vascular function and antioxidant properties. METHODS: An experimental hypertensive model was established by administration of L-NAME (50 mg/kg/day) in drinking water to male Wistar rats for 3 weeks. Arterial pressure was measured indirectly by tail-cuff plethysmography and directly via femoral artery catheterization. Vasoreactivity of isolated rat mesenteric arterial bed was determined by the changes in perfusion pressure detected by a pressure transducer. Vascular superoxide anion (O2•-) production was determined by lucigenin-enhanced chemiluminescence. Other biochemical measurements including malondialdehyde (MDA) level, superoxide dismutase (SOD), and catalase (CAT) activities were measured by colorimetric assay. RESULTS:L-NAME-treated rats developed significantly increased blood pressure and heart rate. Concurrent oral treatment with MOE (30 and 60 mg/kg/day) could decrease the high blood pressure and tachycardia in a dose-dependent manner. MOE reduced the impairment of acetylcholine-induced relaxation and decreased the hyperreactivity of adrenergic-mediated contraction in response to periarterial nerve stimulation and phenylephrine in isolated mesenteric arterial beds. In addition, MOE exhibited antioxidant effects in the hypertensiverats, as indicated by suppression of vascular O2•- production, decrease of plasma and thoracic aorta MDA levels, and increase of antioxidant activities of SOD and CAT. Moreover, MOE (0.001-0.3 mg) produced a dose-dependent relaxation in methoxamine pre-contracted arterial beds isolated from L-NAMEhypertensiverats, which was abolished by endothelium denudation. CONCLUSION: These findings suggest that the antihypertensive effect of MOE in L-NAME-hypertensiverats may be mediated by alleviating vascular dysfunction and oxidative stress and promoting endothelium-dependent vasorelaxation. MOE may be potentially useful as a natural product against hypertension.
Authors: Maisa Gomes da Silva; Sara Léa Fortes Barbosa; Diego Santos Silva; Isadora Basílio Meneses Bezerra; Érika Alves Bezerra; Angélica Gomes Coelho; Ilmara Cecília Pinheiro da Silva Morais; Luis Mário Rezende-Júnior; Iolanda Souza do Carmo; José de Sousa Lima-Neto; Simón Gabriel Comerma-Steffensen; Antônia Maria das Graças Lopes Citó; Daniel Dias Rufino Arcanjo Journal: Evid Based Complement Alternat Med Date: 2022-06-20 Impact factor: 2.650