Comparison of the effects of carvacrol and lidocaine on aconitine-induced arrhythmias in rats

Previous studies have shown that carvacrol has hypotensive, bradycardic and calcium inhibitory effects. Since the opening of calcium channels have an important role in the incidence of arrhythmias, this study aimed to investigate whether carvacrol has anti-arrhythmic effects against aconitine-induced arrhythmia or not. In this experimental study, seventy male Wistar rats were divided into seven groups of ten: Group 1 as the control Group; Group 2 as the pretreatment with lidocaine (10 mg/kg); Group 3 and 4 as the pretreatment with carvacrol 10 and 50 µg/kg; Group 5 as the treatment with lidocaine (10 mg/kg); and Group 6 and 7 as the treatment with carvacrol 50 µg/kg. Lidocaine and carvacrol were infused intravenously as pretreatment and treatment respectively before and after the infusion of aconitine (as an arrhythmic substance). Ventricular arrhythmia including the onset of arrhythmia, incidence percentage of ventricular tachycardia and fibrillation, and irreversible ventricular fibrillation and atrial fibrillation were monitored following the infusion of aconitine for 30 minutes. Data were analyzed in GraphPad Prism statistical software by one-way ANOVA, Tukey’s post hoc test, and Fisher’s exact test. Data showed that the magnitude of ventricular arrhythmia including the onset of arrhythmia, incidence percentage of ventricular tachycardia and fibrillation, and irreversible ventricular fibrillation significantly reduced in pretreatment and treatment groups with lidocaine. It also reduced markedly in pretreatment and treatment groups with carvacrol 50 µg/kg, although not as much as in the lidocaine group. There was not any significant difference between carvacrol 10 µg/kg groups and control group both in pretreatment and treatment protocol. The findings of this study indicate that the maximum dose of carvacrol which did not have any significant effect on blood pressure reduced the magnitude of aconitine-induced arrhythmia. This may use prevention and alternative of cardiac arrhythmias