Pharmacological Actions of Cuscuta reflexa

Abstract

An ethanol extract of Cuscuta Reflexa (CR) caused dose-dependent decreases in arterial blood pres sure and heart rate in pentothal anesthetized rats. These effects were not blocked by atropine (1 mg/ kg) and CR did not alter the pressor response of norepinephrine. These results indicate ihat the hypotensive and bradycardiac effects of CR are independent of cholinergic receptor stimulation or adrenergic receptor blockade. In spontaneously beating guinea-pig atria, CR caused decreases in the force and rate of atrial contractions. These effects remained unaltered in the presence of atropine (0.1 pM). In guinea-pig ileum, CR inhibited both acetylcholine- and histamine-induced contractions to a similar extent. CR also abolished spontaneous contractions of rat uterus. These data indicate that CR in a non-specific depressant on all the isolated tissues tested and this action is probably responsible for its hypotensive and bradycardiac effects observed in vivo.