Effect of the aqueous seed extract of Persea americana mill (Lauraceae) on the blood pressure of sprague-dawley rats

The aqueous seed extract (AE) of Persea americana Mill (Lauraceae) is used by some herbal medicine practitioners in Nigeria for the treatment of hypertension. We investigated its effects on the mean arterial pressure (MAP) and Heart Rate (HR) of naive and 260 mg/kg/day x 10 days pretreated rats. Naive rats were given bolus injections of (a) - AE (240, 260, 280 mg/kg); (b) - 2 mu g/kg of acetylcholine (ACh) + 240, 260, 280 mg/kg of AE; or bolus doses of ACh (1, 2, 4 mu g/kg). Results show that 10-day pretreatment significantly reduced MAP (125.7 +/- 11.2 vs 92.1 +/- 8.5 mm Hg) and HR (274.6 +/- 39.3 vs 161.6 +/- 11.6 beats/min). Also, acute AE injections significantly decreased MAP from baseline values in naive rats. The effects of AE on MAP were comparable with those of ACh. Combination of AE with 2 mu g/kg of ACh only significantly potentiated the MAP reducing effect of 240 mg/kg of AE. It is concluded that the aqueous seed extract of P. americana reduces BP and HR in normotensive rats. This observation lends credence to its use by herbalists for the management of hypertension.