Anti-hypertensive effect of Moringa oleifera Lam

Bioassay-guided fractionation of the crude extracts of Moringa oleifera Lam. using in-vitro angiotensin-converting enzyme inhibition assay was employed to purify the two compounds, namely: quercetin-3-O-glucoside (1) and kaempferol-3-O-glucoside (2). Compound 1 has a significant % of inhibition at varying concentrations: 7 ug/ml (56.37 +/- 0.0059%), 15 ug/ml (59.16 +/- 0.0137%) and 28 ug/ml (75.74 +/- 0.0161%). The methanol extract was found to contain 180.15 ug/ml of compound 1 for every 2 mg/ml of methanol extract after standardization. Furthermore, oral administration of M. oleifera crude extracts did not present acute toxicity in mice. Methanolic and ethyl acetate extracts have significantly reduced systolic blood pressure in N-omega-nitro-L-arginine methyl ester or L-NAME induced hypertensive mice (90.97 +/- 0.7975 mm Hg in methanolic extract treated mice; 87.71 +/- 0.9623 mm Hg in ethyl acetate-treated mice versus 89.21 +/- 0.8025 mm Hg in control group).