Effect of pomegranate (Punica granatum) juice intake on hepatic oxidative stress.

Pomegranate juice (PJ) possesses a high antioxidant activity, which has been related to beneficial health properties. However, in vivo confirmation and characterization of these effects on biological systems are lacking and needed. This study was performed in order to investigate the effect of prolonged PJ ingestion on general oxidation status. For this purpose, mice ingested PJ (or water in control group) during four weeks, after which damage to lipids, proteins and DNA were evaluated as oxidative cell biomarkers. Levels of hepatic glutathione and the activities and expression of enzymes involved in its metabolism were determined. Catalase and SOD activities were quantified as these enzymes have a crucial role in antioxidant defence. Protection against protein and DNA oxidation was found in PJ group. There was also a significant decrease in GSH and GSSG, without change in the GSH/GSSG ratio. All studied enzymatic activities (GPx, GST, GR, SOD and catalase) were found to be decreased by PJ treatment. Additionally, RT-PCR results showed that GST and GS transcription were also decreased in this group. These results are compatible with a protective effect of PJ against systemic oxidative stress in mice.