Moringa oleifera leaf extract lowers high blood pressure by alleviating vascular dysfunction and decreasing oxidative stress in L-NAME hypertensive rats

Phytomedicine. 2019 Feb 15;54:9-16. doi: 10.1016/j.phymed.2018.10.023. Epub 2018 Oct 19.


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.

Keywords: Antihypertensive effect; L-NAME; Mesenteric artery; Moringa oleifera; Oxidative stress; Vascular dysfunction.

MeSH terms

  • Acetylcholine / pharmacology
  • Animals
  • Antihypertensive Agents / chemistry
  • Antihypertensive Agents / pharmacology*
  • Catalase / metabolism
  • Dose-Response Relationship, Drug
  • Heart Rate / drug effects
  • Hypertension / chemically induced
  • Hypertension / drug therapy
  • Male
  • Malondialdehyde / metabolism
  • Mesenteric Arteries / drug effects
  • Mesenteric Arteries / physiology
  • Moringa oleifera / chemistry*
  • NG-Nitroarginine Methyl Ester / adverse effects
  • Oxidative Stress / drug effects*
  • Plant Extracts / administration & dosage
  • Plant Extracts / chemistry
  • Plant Extracts / pharmacology*
  • Rats, Wistar
  • Superoxide Dismutase / metabolism
  • Vasodilation / drug effects


  • Antihypertensive Agents
  • Plant Extracts
  • Malondialdehyde
  • Catalase
  • Superoxide Dismutase
  • Acetylcholine
  • NG-Nitroarginine Methyl Ester