Effect of melatonin on the gastric antioxidant defence in experimental burn trauma

Abstract

Severe burn trauma triggers oxidative gastric mucosal injury. The purpose of this study was to investigate the antioxidant defence mechanisms and protective effect of melatonin in the gastric mucosa after burn injury. In order to investigate the mechanisms involved in the gastric antioxidant defence in a rat burn model, quantitative real-time PCR and immunohistochemistry techniques were applied. An analysis of glutathione peroxidase 4 (GPx4), glutathione reductase (GR), and catalase (Cat) gene expression was performed along with the evaluation of the gastric Cu/Zn superoxide dismutase (Cu/Zn SOD) activity. Melatonin was applied immediately and 12 h after 30% of total body surface area burns. The burn injury significantly increased the Gpx4 mRNA (P < 0.000 1) and Gsr mRNA (P < 0.000 1) expression. It also had a slight positive effect on the Cat mRNA expression and Cu/Zn SOD activity. Melatonin, in turn, markedly augmented the burn-induced Cu/Zn SOD (P < 0.000 1) activity, reversed the Gpx4 mRNA (P < 0.000 1) and Gsr mRNA (P < 0.000 1) expression, and inhibited the Cat mRNA level. In conclusion, the present study suggests that a burn injury adaptively increases the Cu/Zn SOD activity and enhances the Gpx4 and Gsr gene expression in the gastric mucosa. Melatonin effectively modulates the expression of the cellular antioxidant enzymes, and improves the antioxidant defence by augmenting the Cu/Zn SOD activity.

Keywords

• gastric mucosa
• oxidative stress
• thermal injury