No abstract

Pomegranate juice (Pg) has demonstrated cardiovascular beneficial effects. The current research intends to investigate the roles of nitric oxide (NO) and antioxidants in Pg-induced cardioprotection against ischemia and reperfusion (I/R). Isolated hearts from anesthetized rats were subjected to 30-min global ischemia followed by 120-min reperfusion. The hearts in the test groups were treated with Pg, N -nitro-L-arginine methyl ester (L-NAME) or both throughout the experiment. In Pg group, left ventricular developed pressure, rate of rise in left ventricular pressure (dp/dt max), and rate pressure product were 83%, 55%, and 127%, respectively, higher than those of the control group (p < 0.05). The infarct size declined to less than 40% (p < 0.0001), and biomarkers of myocardial damage including creatine kinase-MB, lactate dehydrogenase, and troponin-I, showed significant reductions (59%, 36%, and 94%, respectively) compared with the control. Furthermore, the indices of oxidative status including superoxide dismutase, glutathione peroxidase, catalase, and malondialdehyde showed significant improvement (2.4, 1.7, 1.9, and 2.4 fold, respectively). Most of these effects were mainly blocked by L-NAME. These results suggest potent cardioprotective effects for Pg against myocardial I/R injury. The current results suggest a key role for NO for this cardioprotection; however, other mechanisms seem to be also involved.

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.