The effects of liquid extract of Allium sativum on the basic and speed-dependent electrophysiological properties of islolated atrioventicular nodal of rabbit

Herbal treatments are suitable replacement for synthetic drugs due to their availability, minimal side effects and low price. Previous studies about pharmacologic and biochemical effects of Allium sativum (garlic) have shown antihypertensive, anti arrhythmic, negative inotropic and chronotropic activities. The aim of this study was to assess the effects of liquid extract of Allium sativum on the basic and rate-dependent electrophysiological properties of isolated atrioventricular (AV) nodal of rabbit. In the present study we used isolated perfused AV-Nodal rabbit (1.5-2 kg) preparation including right atrium, intra-atrial septum and His bundle of rabbit as an experimental model to determine the effects of various concentration of aqueous extract of Allium Sativum. Selective stimulation protocols (recovery, facilitation and fatigue) were used to independently assess AV nodal properties in 14 rabbits (two groups). In the first group of experiment (n=8 rabbits), different concentrations (20, 30, 100, 850 mg/lit) of Allium Sativum and in the second group verapamil (0.1 m) (n=6 rabbits) was applied. Data were analyzed using ANOVA and Wilcaxon tests. The results of this research indicate a significant effect of various concentrations of Allium sativum on basic electrophysiological parameters of atrioventricular node (WBCL, recovery, facilitation, fatigue) and fatigue (P<0.05). In the presence of garlic (20 mg/lit), AVCT (atrioventricular conduction time) increased from 41.3±5.3 to 45.6±5.1msec and FRP (functional refractory period) increased from 108.6±14.4 to 167±1.1msec (P<0.05). The Allium sativum extract has less inhibitory effect in comparison with verapamil on the basic parameters (P<0.05) of Node. The above results showed potential antiarrhythmic properties of Allium sativum by increasing fatigue and refractory period. Therefore, it may be considered for treatment of supraventricular arrhythmias.