The effect of zinc on ethanol-induced oxidative stress in rat liver

Aim Zinc is known as an essential trace element and has antioxidant functions. This study was planned to investigate the effects of zinc on oxidative stress induced by ethanol in the rat liver tissue. Methods: Thirty-nine male rats were divided into four groups as control, ethanol (EtOH), zinc (Zn), ethanol plus zinc (EtOH+Zn). The control group (n=10) were injected intraperitoneally (i.p.) with 0.9% saline, EtOH group (n=10) with 2g kg/day ethanol, Zn group (n=10) received orally, ZnSO4.7H(2)O at a dose of 7 mg kg/day and EtOH+Zn group (n=9) received zinc (orally) and ethanol (i.p.). On the 13th day, rats were euthanized. Liver tissues were removed and malondialdehyde (MDA), advanced oxidation protein products (AOPP), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR), and glutathione-S-transferase (GST) activities were measured. Tissue zinc levels were determined. Histological analyses of liver tissue specimens were also performed. Results: In EtOH group MDA levels, GPx, SOD activities increased compared with control group. In accordance with histological findings, ethanol induced oxidative stress. But AOPP levels decreased in EtOH group due to supressive effect of ethanol on neutrophil activation and reactive oxygen species (ROS) production. In EtOH+Zn group, MDA, AOPP levels and GPx, SOD activities significantly changed. Besides, histological findings showed that zinc supplementation reduced oxidative stress. But in healthy rats MDA levels increased due to ROS mediated zinc damage. Conclusion: Zinc supplementation was found to offer protection against ethanol-induced liver damage and oxidative stress in rats. However, zinc might increase oxidative stress in healthy rats.