Hepatoprotective effects of apple polyphenol extract on aluminum-induced liver oxidative stress in the rat.

This study was undertaken to determine the effectiveness of apple (Ralls) polyphenol extract (APE) in modulating aluminum chloride (AlCl3) induced hepatotoxicity in rats. The rats were distributed among 4 groups and fed different diets with or without AlCl3 (171.8 mg Al·kg(-1)·day(-1)) and APE (200 mg·kg(-1)·day(-1)) for 10 weeks. The activities of superoxide dismutase and catalase as well as the levels of glutathione and ATP synthesis were decreased by comparison with the control, while the activities of transaminases in serum, the levels of Al, and ATP hydrolysis were increased significantly in the liver of the Al-treated group. Furthermore, abnormal changes in the histological structure of the liver were observed in the Al-treated group. However, these toxic effects of Al were significantly reduced when the rats were fed diets supplemented with APE. This suggests that APE plays a role in the reduction of the toxic effects from Al in rats.

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 Ca(2+)-ATPase and Mg(2+)-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.

Antioxidant properties of the mung bean flavonoids on alleviating heat stress.

BACKGROUND: It is a widespread belief in Asian countries that mung bean soup (MBS) may afford a protective effect against heat stress. Lack of evidence supports MBS conferring a benefit in addition to water. RESULTS: Here we show that vitexin and isovitexin are the major antioxidant components in mungbean (more than 96% of them existing in the bean seed coat), and both of them could be absorbed via gavage into rat plasma. In the plasma of rats fed with mungbean coat extract before or after exposure to heat stress, the levels of malonaldehyde and activities of lactate dehydrogenase and nitric oxide synthase were remarkably reduced; the levels of total antioxidant capacity and glutathione (a quantitative assessment of oxidative stress) were significantly enhanced. CONCLUSIONS: Our results demonstrate that MBS can play additional roles to prevent heat stress injury. Characterization of the mechanisms underlying mungbean beneficial effects should help in the design of diet therapy strategies to alleviate heat stress, as well as provide reference for searching natural medicines against oxidative stress induced diseases.