The anti-arrhythmic effects of pomegranate (Punica granatum) are mainly mediated by nitric oxide

BACKGROUND: Pomegranate juice (PJ) contains strong antioxidant polyphenols, and cardiovascular beneficial effects have been reported for the fruit. OBJECTIVE: Using a Langendorff's model, we hypothesized that PJ has antiarrhythmic effects on isolated rat hearts. METHODS: The hearts in the control group (n = 10) were perfused with Krebs solution. The test groups (n = 10, each) were further perfused with PJ, L-NAME (L), or both (PJL). Following 30 min stabilization, all hearts experienced 30 min global ischemia and 120 min reperfusion. The hearts were monitored for the occurrence of single and salvo arrhythmias, ventricular tachycardia (VT), and ventricular fibrillation (VF). The cardiac release of creatine kinase-MB (CK-MB), lactate dehydrogenase (LDH), and nitrite were measured. In addition, the markers of oxidative stress including superoxide dismutase (SOD), glutathione peroxidase (GPX), catalase (CAT), and malondialdehyde (MDA) were assayed in the homogenates of the hearts. RESULTS: The PJ group showed a significant reduction in the occurrence of arrhythmias, an improvement in redox markers, and a rise in nitrite release, compared to the control. Simultaneous treatment with L-NAME significantly reduced, but not fully abolished, these effects. CONCLUSIONS: The current study suggests strong anti-arrhythmic effects for PJ, which are mainly mediated by nitric oxide.