Send to

Choose Destination
Pharm Biol. 2012 Nov;50(11):1436-41. doi: 10.3109/13880209.2012.684690. Epub 2012 Sep 11.

Possible mechanisms of action of the hypotensive effect of Annona muricata (soursop) in normotensive Sprague-Dawley rats.

Author information

Department of Basic Medical Sciences (Physiology Section), The University of the West Indies, Mona, Kingston 7, Jamaica.



Annona muricata Linn (Annonaceae) (soursop) is a food plant reported to have antihypertensive properties.


We investigated the blood pressure reducing effect of its aqueous leaf extract and the possible mechanisms that may be responsible.


Intravenous administration of an aqueous leaf extract (9.17-48.5 mg/kg) of A. muricata on the mean arterial pressure and heart rate were recorded invasively on anaesthetized, normotensive Sprague-Dawley rats. Contractile responses of rat aortic rings to the extract (0.5-4.0 mg/mL) were studied using standard organ bath techniques.


A. muricata (9.17-48.5 mg/kg) caused significant (p < 0.05) dose-dependent reduction in blood pressure without affecting the heart rates. The hypotensive effects were unaffected by atropine (2 mg/kg), mepyramine (5 mg/kg), propranolol (1 mg/kg) and L-NAME (5 mg/kg). A. muricata leaf aqueous extract significantly (p < 0.05) relaxed phenylephrine (10(-9)-10(-4) M) and 80 mM KCl induced contractions in endothelium intact and denuded aortic rings; and caused a significant (p < 0.05) rightward shift of the Ca(2+) dose response curves in Ca(2+)-free Kreb's solution containing 0.1 mM EGTA.


The hypotensive effects of A. muricata are not mediated through muscarinic, histaminergic, adrenergic and nitric oxide pathways, but through peripheral mechanisms involving antagonism of Ca(2+).

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Taylor & Francis
Loading ...
Support Center