Effects of Barakol on aconitine-induced cardiac arrhythmias

Barakol, isolated from leaves of Cassia siamea Lam., was investigated on aconitine-induced cardiac arrhyihmias in anesthetized rats. The bolus intravenous injection of aconitine induced ventricular fibrillation (VF) and ventricular tachycardia (VT). Pretreatment with barakol (10 mg/kg i.v.) reduced the incidence of aconitine-induced VF and VT, as well as mortality. However, pretreatment with verapamil (1 mg/kg) was ineffective on aconitine-induced ventricular arrhythmias and mortality. Tetrodotoxin (5 µg/kg i.v.) also significantly reduced the incidence of VF, VT and mortality induced by aconitine. Our results suggest that intracellular Na + loading plays an important role in aconitine-induced ventricular arrhyihmias. We concluded that the mechanisms of the protective effects of barakol on aconitine-induced cardiac toxicity may relate to the prevention of intracellular Na + accumulation.