Protective effect of pharmacologic postconditioning with Natural Honey against left ventricular ischemia/reperfusion-induced arrhythmias in isolated heart of rat

This study was aimed to investigate the effects of postconditioning by natural honey on cardiac arrhythmias in the ischemic isolated rat heart. Male Wistar rats were divided into four groups then anesthetized by sodium pentobarbital. The animal hearts were removed and quickly mounted on a Langendorff apparatus and perfused under constant pressure by a modified Krebs-Henseleit (K/H) solution that was previously equilibrated with 95% O2–5% CO2. The hearts were subjected to 30 min regional ischemia followed by 30 min reperfusion. In the control group, the hearts perfused by normal K/H solution, however in the postconditioning groups, they were perfused with natural honey (0.25, 0.5 and 1%) enriched K/H solution from 10 min before to 10 min after reperfusion. The ECGs were analyzed to determine the total number of ventricular ectopic beats (VEBs), ventricular tachycardia (VT), the incidence and duration of VT and ventricular fibrillation (VF) during last 10 min of ischemia and the first 30 min of reperfusion. During ischemia, honey (0.25, 0.5 and 1%) produced significant reduction in the number of VEBs and number, duration and incidence of VT (P<0.01). The incidence and time spent in VF were lowered by honey compared to the control group (P<0.05). During reperfusion time, all used concentrations of honey significantly reduced the number of VEBs (P<0.05). In addition, honey (0.5 and 1%) decreased the number and duration of VT (P<0.01 and P<0.05, respectively). Moreover, VF duration was lowered by perfusion of honey (0.25 and 0.5 %) versus the control group (P<0.05). The results showed protective effects of postconditioning by honey against ischemia-reperfusion injuries as anti-arrhythmic activities. Probably, antioxidant activity of honey, by scavenging of free radicals, and the presence of important energy sources such as glucose and fructose by improvement of cardiac function may involve in these protective effects.