Antihypertensive Effect of Moringa oleifera (Moringaceae) Methanolic Leaf Extract (MoMLE) on Cricetomys gambianus (Muridae)

Abstract

Cardiovascular diseases are on the rise around the world and have become some of the leading causes of death. To enhance their chances of survival and effectively manage costs, indigenous communities in developing countries have sought natural remedies from plants and food materials within their reach. This established preference has seen Moringa oleifera garner special attention due to the praised effects of its leaves and other parts. The focus of this study was to investigate the antihypertensive activity of crude MoMLE (CME) and five solvent fractions of the same using C. gambianus and elucidate the effect of their separate interactions with atropine. Moringa oleifera (MO) leaf was collected from the University of Nigeria, Nsukka; C. gambianus was obtained from Okposi-Okwu, Ebonyi State; and antihypertensive activity was assessed using a blood pressure transducer following established methods. The result showed that CME and other fractions had a dose-dependent negative inotropic and chronotropic effect on C. gambianus as follows: N-Hexane fraction (NHF)-19.0 8.1 mmHg, chloroform fraction (CLF)-15.0 3.0 mmHg, ethyl acetate fraction (EAF)-22.3 10.7 mmHg, acetone fraction (ACF)-19.7 7.2 mmHg, and methanol fraction (MEF)-25.7 1.2 mmHg. Similar activity was observed for acetylcholine (-42 ± 4.4 mmHg) which was used as a reference drug (positive control). The study revealed that MoMLE has a hypotensive effect with methanol fraction (MEF) having the second highest hypotensive (-25.7 ± 1.2 mmHg) activity after CME with a 28.7 ± 4.2 mmHg lowering effect. Atropine interaction blocked the extracts as well as acetylcholine, suggesting a muscarinic-receptor mediated action.