Comparison of Hypotensive Effect of Azadirachta Indica Extract withAntihypertensive Drugs in Spontaneously Hypertensive Rat

摘要

Studies on Azadirachta indica (Neem) leaf extracts in animal models shown to reduce the blood pressure. Therefore in thisstudy, the hypotensive effect of Neem extract was compared with three classes of antihypertensive drugs : Clonidine , Enalapriland Amlodipine on systolic blood pressure (SBP) in Spontaneously Hypertensive Rat (SHR). SHR were divided into fivegroups [SHR, SHR+Clonidine, SHR+Enalapril, SHR+Amlodipine and SHR+Neem) and n=6/group. Rats were administeredwith Clonidine (0.5 mg kg-1 day-1), Enalapril (30 mg kg-1 day-1), Amlodipine (10 mg kg-1 day-1) in drinking water and Neem[2.5% (w/v) aqueous extract daily] from 4 weeks until 28 weeks. Normotensive Wistar Kyoto (WKY) rats were served ascontrol . SBP was measured in all groups during the experimental period at 4, 10 , 16, 22 and 28 weeks. Hypertension wasindicated to be present in SHR at 10th weeks onwards as the SBP of SHR was significantly higher when compared to WKY.Neem extract had the similar hypotensive effect as antihypertensive drugs at 10 weeks, with significant reduction in SBP ofdrug treated SHR when compared to untreated SHR (p<0.001). At 16 weeks and 22 weeks, the hypotensive effect neem extractwas still present (p<0.001) but was reduced. However, the hypotensive effect was diminished at 28 weeks whereasantihypertensive drugs treatment showed significant reduction in SBP when compared to untreated SHR. The results of thisstudy showed that Neem extract has hypotensive effect on SHR only at an early stage of hypertension unlike theantihypertensive drugs.