Effect of aqueous extract of Commiphora opobalsamum on blood pressure and heart rate in rats

The cardiovascular effects of aqueous extracts from the branches of Commiphora opobalsamum tree were investigated. The intravenous administration of 4 mg/kg of the aqueous extract depressed systemic arterial blood pressure by 20% (P < 0.01) and reduced heart rate of anaesthetised rats by 14% (P < 0.05). The hypotensive and the bradycardiac effects were immediate and in a dose related manner. The hypotensive effect of C. opobalsamum was inhibited by the pretreatment with atropine sulfate (1-4 mg/kg). These results suggest that the hypotensive effect of C. opobalsamum is due to the activation of muscarinic cholinergic receptors. (C) 1997 Elsevier Science Ireland Ltd.