Protective effect of fermented papaya preparation on stress-induced acute gastric mucosal lesion

Stress ulceration is single or multiple mucosal defects with/without bleeding from the gastric mucosa during the physiologic stress. Oxidative stress (OS) is a key pathogenic factor in psychogenic stress-induced acute gastric mucosal lesion (AGML). Fermented papaya preparation (FPP) is reported to have oxygen radical scavenging activity and is effective in OS-related diseases. Here, we investigated the protective effects and the mechanism of action of FPP on stress-induced AGML in rats, induced by water immersion restraint stress (WIRS). Exposure of rats to 6-hour WIRS resulted in the appearance of splinter hemorrhages and mucosal lesions in the stomach. WIRS induced significant increase in lipid peroxidation and decrease in superoxide dismutase-like activity in both the plasma and gastric mucosa. WIRS also significantly increased myeloperoxidase activity together with Nuclear factor-kappaB (NF-kB) activation in gastric mucosa. FPP reduced all the above changes. The results suggest that oral administration of FPP provides protection against WIRS-induced acute gastric mucosal lesions through its anti-oxidative and anti-inflammatory properties.