Protective Effect of Repeatedly Preadministered Brazilian Propolis Ethanol Extract against Stress-Induced Gastric Mucosal Lesions in Rats

The present study was conducted to clarify the protective effect of Brazilian propolis ethanol extract (BPEE) against stress-induced gastric mucosal lesions in rats. The protective effect of BPEE against gastric mucosal lesions in male Wistar rats exposed to water-immersion restraint stress (WIRS) for 6 h was compared between its repeated preadministration (50 mg/kg/day, 7 days) and its single preadministration (50 mg/kg). The repeated BPEE preadministration attenuated WIRS-induced gastric mucosal lesions and gastric mucosal oxidative stress more largely than the single BPEE preadministration. In addition, the repeated BPEE preadministration attenuated neutrophil infiltration in the gastric mucosa of rats exposed to WIRS. The protective effect of the repeated preadministration of BPEE against WIRS-induced gastric mucosal lesions was similar to that of a single preadministration of vitamin E (250 mg/kg) in terms of the extent and manner of protection. From these findings, it is concluded that BPEE preadministered in a repeated manner protects against gastric mucosal lesions in rats exposed to WIRS more effectively than BPEE preadministered in a single manner possibly through its antioxidant and anti-inflammatory actions.