Bergenin is the antiarrhythmic principle of Fluggea virosa.

Bergenin was isolated from the aerial parts of Fluggea virosa (Euphorbiaceae). Its structure was elucidated on the basis of chemical and spectral data. Anti-arrhythmic effects of bergenin were investigated. At concentrations of 0.2 mg/kg, 0.4 mg/kg, and 0.8 mg/kg, bergenin showed distinct therapeutic effects on BaCl2-induced arrhythmias in rats. At concentrations of 0.4 mg/kg and 0.8 mg/kg bergenin significantly countered arrhythmias induced by ligation and reperfusion of the coronary artery. At 0.8 mg/kg, bergenin elevated the atria fibrillation threshold in rabbits from 1.34 mV to 1.92 mV. Our results suggest that bergenin has good potential to treat cardiac arrhythmias.