Abstract:
Acacia jacquemontii Benth. is used traditionally to treat hypertension but no scientific literature supports this claim. So, this study was aimed at validating this claim. This was done by injecting various doses of crude extract of Acacia jacquemontii, AJC (5, 10, 20, 30mg/kg) and all fractions (hexane, ethyl acetate, n-butanol and aqueous) (3, 5, 10, 20mg/kg) intravenously in anaesthetized rat. Based on the results, butanol fraction (AJB) at 20mg/kg was found to be the most potent, so it was selected for exploring mechanisms of action. For this purpose, different groups were injected with various pharmacological inhibitors (L-NAME, atropine, captopril, propranolol and hexamethonium) prior to AJB administration. Also, AJB at 20mg/kg was evaluated for prolonged hypotensive effect for the period of 40 min. Results showed a significant dose dependent reduction in BP in normotensive and in hypertensive rats. AJC and AJB produced a decline in SBP, DBP and MAP with p<0.05 - p<0.001 and p<0.001 respectively in normotensive animals. Whereas in hypertensive animals, AJC showed significant reduction at 5mg/kg with p<0.01 and at 10, 20 and 30 mg/kg with p<0.001. AJB produced a decline in hypertensive animals at all tested doses with p<0.001. AJB resulted in hypotensive effect mediated by β receptors, ganglionic block operating central sympathetic neural responses and renin angiotensin aldosterone system (RAAS). This study supports the ethnomedicinal claim of Acacia jacquemontii Benth. in treating hypertension.
