The protective effects of polyphenols from jujube peel (Ziziphus Jujube Mill) on isoproterenol-induced myocardial ischemia and aluminum-induced oxidative damage in rats

This study was aimed to evaluate the preventive effect of the polyphenols from Chinese jujube peel (Ziziphus jujube Mill. cv. Dongzao) against myocardial injury (MI) induced by isoproterenol (ISO) and biotoxicity of aluminum in rats. The free phenols from jujube peel (JPFP) and the bond phenols from jujube peel (JPBP) were administered to rats by gastric gavage. The results showed that prior administration of JPFP or JPBP remarkably inhibited increases in levels of malondialdehyde (MDA) and activities of Ca²⁺-ATPase and Mg²⁺-ATPase, reductions in activities of superoxide dismutase (SOD), glutathione peroxidase, creatine kinase, lactate dehydrogenase and Na⁺/K⁺-ATPase in the rats induced by ISO. The abnormal changes in morphology of heart muscle and in electrocardiograph induced by ISO treatment were also significantly prevented by the JPFP or JPBP. Treatment with aluminum chloride could cause a significant oxidative damage, including a significant increase in MDA level and decreases in glutathione-S- transferase and SOD activities in brain of the rats, the study showed that gavage with JPFP or JPBP could remarkably alleviate the toxic responses of the rats to aluminum chloride. In summary, our study showed that jujube phenolics can prevent ISO-induced myocardial injury and reduce aluminum toxicity in rats.