Talat Roome, Ahsana Dar and Muhammad Iqbal Choudhary
Molecular Pathology, Department of Pathology, Dow Diagnostic Reference and Research Laboratory, Dow International Medical College, Dow University of Health Sciences, Karachi, Pakistan
Hypertension is a pathological condition with a persistent elevated blood pressure is the leading cause of death worldwide. Hypertension causes endothelial dysfunction by impairing vascular relaxation eventually develops pressure on the heart. Endothelial disruption cause inhibition of the release of vasodilators (nitric oxide) leading to alteration in vascular cell functions. Cholinergic/noradrenergic receptors along with voltage-operated channels are involved in control in vascular targets.
A. corniculatum comprises various novel chemical constituents and used in folklore medicine against rheumatism and cardiovascular diseases however scientifically not proven yet. In the present investigation hypotensive effect of Aegiceras corniculatum, methanol and ethyl acetate extracts and their mechanism of actions were experimentally evaluated in in vivo and in vitro using normotensive rats and rabbit aortic rings.
Methanol extract has shown tremendous effect at 10 mg/kg i.v. in reducing mean arterial blood pressure (MABP) 79.2±1.8mmHg as compared to control group of 128.2 ± 0.8mmHg in rats, which was significantly suppressed (33%) in the presence of atropine. Furthermore, methanol extract failed to produce vasodilation in endothelium denuded rabbit aorta and in the presence of L-NAME a nitric oxide synthase inhibitor in phenyleprine contracted tissue. Whereas, ethyl acetate extract exhibited inhibition (35-67%) in % fall in mean arterial blood pressure (MABP) in the presence of nifidipine (0.3-0.9 mg/kg, i.v.). Anti-hypertensive effect of extracts were further supported by anti-platelet aggregation and eNOS activation.
Methanol and ethyl acetate extracts possess significant hypotensive and vasodilatory activity via muscarinic receptor dependent release of endothelium derived relaxing factor, nitric oxide and calcium channel blocking potential, thus the study validates traditional use of A. corniculatum against cardiovascular disorders.