Antianginal and antiarrhythmic effects of bergamottine, a furocoumarin isolated from bergamot oil

The antianginal and antiarrhythmic activities of bergamottine, a furocoumarin, were investigated in various in vivo and in vitro test models and have been compared with those of verapamil, a well-known Ca-antagonistic drug. Bergamottine significantly decreased the typical electrocardiographic signs of coronary arterial spasm and the incidence of cardiac arrhythmias induced by pitressin in anaesthetized guinea-pigs. Bergamottine also increased the dose of ouabain required to cause ventricular premature beats, ventricular tachyarrhythmias and lethality. Bergamottine further reversed ouabain-induced persistent ventricular tachycardia and restored sinus rhythm in the guinea-pig. On isolated rat heart, bergamottine exerted a coronary dilator action and was able to reduce the hyperkinetic ventricular arrhythmias caused by post-ischaemic reperfusion. These results demonstrate that bergamottine possesses significant antianginal and antiarrhythmic properties and suggest that this furocoumarin is one of the active components responsible for the cardiovascular activity previously exhibited by non-volatile bergamot oil.