| Abstract: | An ethanolic extract of Capparis cartilaginea (CC) at a dose of 1–10 mg/kg caused a dose-dependent fall in blood pressure and heart rate in anaesthetized rats. These effects were not blocked by atropine (1 mg/kg) and pretreatment with CC did not alter the pressor response to norepinephrine, indicating that the cardiovascular effects of CC are independent of cholinergic or adrenergic receptor involvement. In spontaneously beating guinea-pig atria, CC induced a concentration-dependent (0.1–1 mg/mL) decrease in force and rate of atrial contractions. In rabbit thoracic aorta, CC caused inhibition of norepinephrine or K+-induced contractions. In guinea-pig ileum, CC (1 mg/mL) inhibited submaximal contractions induced by acetylcholine, histamine or 5-HT. Spontaneous contractions of rat uterus were also abolished when CC was added to the tissue bath at similar concentrations. These results suggest that the direct relaxant action of CC on myocardium and blood vessels may be responsible for its hypotensive and bradycardiac effects observed in the in vivo studies. Moreover, CC exhibits general spasmolytic activity in different smooth muscle preparations. |
