Alchornea Cordifolia (Euphorbiaceae), the Major Constituent of Antiasthmatic Herbal Formulations in Ghana, Stimulates β- adrenoceptors.

Abstract

We have investigated the scientific basis for the traditional use of Alchornea cordifolia (Euphorbiaceae), by using isolated tissue models of smooth muscles in the laboratory. The aqueous extract of the leaves of Alchornea cordifolia produced a dose-related relaxation of the isolated rabbit duodenum in a manner similar to noradrenaline, adrenaline and isoprenaline, which were antagonised by propranolol (10μg/ml) by 63% but not phentolamine, suggesting a non-specific β- receptor-mediated activity. Additionally, the extract (12mg) evoked increased rate and force of contraction similar to isoprenaline on the Langendorff's isolated perfused rabbit heart preparation by 87% by an action on β1- receptors. These effects were blocked by propranolol (0.1mg), a nonspecific β-blocker. Carbachol-induced contractions on the guinea-pig tracheal smooth muscle were reversed by the extract in a cumulative dose manner, akin to the bronchodilator actions of isoprenaline.
Similarly, 4μg/ml carbachol-elicited contractions on both pregnant and non-pregnant rat
uterus were antagonised by the extract (50mg/ml) by 72% and 64% respectively. All together, our data suggest that the extract stimulates smooth muscles through activation of β-adrenoceptors in a manner similar to isoprenaline, which supports its traditional use as a constituent of anti-asthmatic and cough formulations, and in the control of spontaneous abortion.

Journal of the Ghana Science Association Vol. 10 (2) 2008: pp. 1-11