Blood Pressure Lowering Effect of Adenanthera pavonina Seed Extract on Normotensive Rats

The effect of Adenanthera pavonina (AP) seed extract on the blood pressure of normotensive rats was evaluated. Twelve adult male Wistar rats divided into 3 groups of 4 animals each were used and were treated orally with normal saline (control group), propanolol (positive control, and was given at 1mg/kg) and 200mg/kg of AP seed extract over a 4- week period. Condon manometer was used to measure the mean arterial blood pressure. The mean arterial blood pressure of the normal saline treated animal was 60mmHg, those of propanolol treated animals was 23mmHg while the 200mg/kg extract treated group was 30mmHg. Phytochemical screening showed that the extract contained cardiac glycosides, tannins, saponins, alkaloids and flavonoids. Cyanogenetic glycosides and anthraquinones were absent. The sodium level for the 200mg/kg group was significantly lower than that of control group. The total bilirubin, total protein and the globulin fraction were significantly higher in the extract treated groups compared to the control group. Histopathological examination showed that the extract did not cause any significant lesion changes in the liver, kidney and even the testes. The study showed that Adenantherapavonina seed extract have the potential to cause a blood pressure lowering effect. The serum biochemistry changes may suggest that the extract has a tonic effect on the kidneys and the liver and these organs play central role in drug metabolism. Absence of significant lesion in the kidney, liver and testes may indicate that the plant is safe for medicinal use.