Dauricine(Menispermun dauricum DC.) is a calcium channel blocker. It is the main toxin that makes the North American vine Menispermum canadense (moonseed) poisonous (often fatally so). Dauricine is the major bioactive component isolated from the roots of Menispermum dauricum D.C. and has shown promising pharmacological activities with a great potential for clinic use. However, the adverse effects and toxicity of the alkaloid are unfortunately ignored. The objective of the current study was to evaluate the toxicity of dauricine in vitro and in vivo. Antagonistic effect of dauricine of experimental arrhythmias; Protective and anti-arrhythmic effects of dauricine and verapamil on acute myocardial infarction in anesthetized dogs. Dauricine and anisodamine inhibited the DNA synthesis of the cells induced by LT and PAF (0.1-100 mumol.L-1). These results indicate the bright future of the 2 drugs in the prevention and treatment of cerebral vascular diseases.