The effect of polaprezinc on gastric mucosal protection in rats with ethanol-induced gastric mucosal damage: comparison study with rebamipide.

Polaprezinc (PZ), which consists of l-carnosine and zinc, is widely used to treat gastric ulcers. We compared the effects of PZ with those of rebamipide (RM) on the expression of inflammatory cytokines, antioxidants, growth factors, and heat shock proteins (HSP) in a rat model. Seventy Sprague-Dawley rats were randomly assigned to test groups according to the dose of PZ at 5, 10, or 30 mg/kg or RM at 10, 30, or 100 mg/kg. Next, we obtained ulcer indices from rats with ethanol-induced gastric mucosal damage. Western blot analysis was used to evaluate the expression of various target proteins. Pathological ulcer indices in the PZ and RM groups were significantly lower than those in the control group. The levels of inflammatory cytokines (interleukin 1β [IL-1β], IL-6, IL-8, and tumor necrosis factor α) decreased, whereas the levels of platelet-derived growth factor-B, vascular endothelial growth factor, and nerve growth factor significantly increased after PZ administration. Furthermore, the expression of antioxidants (superoxide dismutase 1 [SOD-1], SOD-2, heme oxygenase-1, glutathione S-transferase, peroxidredoxin-1, and peroxidredoxin-5) was significantly higher in the PZ group, and the levels of HSP 90, 70, 60, 47, 27, and 10 significantly increased with an increase in PZ dose. In a rat model of ethanol-induced gastric mucosal damage, PZ administration ameliorated ethanol-induced mucosal injury and showed protective effects on the mucosa by reducing the levels of inflammatory cytokines and increasing the expression of antioxidant enzymes and growth factors. Furthermore, PZ showed cytoprotective effects by increasing the HSP levels.