Cardiac toxicity of resibufogenin: electrophysiological evidence

Resibufogenin (RBG) is a single compound isolated from Chansu, a traditiona l Chinese medicine obtained from the skin venom gland of the toad. Formulat ions of Chansu have been widely applied in China, Japan, and other Asian co untries for a long time and are currently used as alternative medicines. Ho wever, there have been several reports about the toxicity of Chansu and its medical formulations in the United States recently. As digitalis, RBG poss esses both pharmacologic and toxicologic effects. According to our study re sults, RBG, one of major ingredient of Chansu, induced delayed afterdepolar ization and triggered arrhythmias both in cardiac fiber in vitro and in bea ting heart in ville at the high concentrations. The electrophysiologic toxi c effects of RBG, the possible mechanism of toxicity, and treatment possibi lities are discussed in the present review.