Phloroglucinol protects gastric mucosa against ethanol-induced injury through regulating myeloperoxidase and catalase activities

It has been shown that oxidative stress plays an important role in the pathogenesis of ethanol-induced acute gastric mucosal injury, and phloroglucinol, a smooth muscle relaxant, has been reported to possess anti-oxidative properties. In this study, we explored the effect of phloroglucinol on ethanol-induced gastric mucosal injury and the possible underlying mechanisms. The rat model of gastric mucosal injury was induced by oral administration of acidified ethanol, and the gastric tissues were collected for analysis of gastric ulcer index (UI), cellular apoptosis, anti-O(2) ˙ or OH˙ formation activity, malondialdehyde (MDA) content, and the activities of myeloperoxidase (MPO), catalase and glutathione peroxidase. The results showed that acute administration of ethanol significantly increased gastric UI concomitantly with the increased cellular apoptosis, MDA contents, MPO activity as well as the decreased activities of catalase and anti-O(2) ˙ or OH˙ formation, which was reversed by pretreatment with phloroglucinol. Although ethanol treatment significantly decreased the activity of glutathione peroxidase, pretreatment with phloroglucinol did not significantly affect the activity of the same. The results suggest that phloroglucinol could protect the gastric mucosa against ethanol-induced injury, which is related to inhibiting the MPO activity and increasing the catalase activity in the gastric tissues.