The effect of an Aqueous Extract of Bark of Anarcadium occidentale L. (Anacardiaceae) on Arterial Blood Pressure and Respiratory Movements in the Rabbit

An aqueous extract of Anacardium occidentale (AEAo) with a concentration from 1 mg / kg b.w. to 50 mg / kg b.w. induces dose-dependent hypotension on rabbit arterial blood pressure (p <0.01). The respiratory movements of the animal grow in amplitude and frequencies. High doses of 40 and 50 mg / kg b.w. lead to severe hypotension followed by respiratory gasps. AEAo reduces hypertension induced by adrenaline to 5x10-3 mg / kg p.c. Injected to the animal before or after the injection of adrenaline, AEAo reduces hypertension. The greatest reduction occurs when AEAo is injected before the adrenaline injection (p <0.01). Hypertension induced by adrenaline results in a decrease in the amplitude of respiratory movements (p <0.05). Injection of AEAo rapidly restores these depressed respiratory movements (p <0.01). Atropine significantly reduces hypotension induced by AEAo. This suggests that this hypotension is due to muscarinic cholinergic substances contained in the plant. The presence of atropine abolishes the observed gasp respiratory effect. Respiratory movements under these conditions are not significantly modified (p <0.05).