Effect of quinacrine, a phospholipase A2 inhibitor on stress and chemically induced gastroduodenal ulcers.

Quinacrine, a phospholipase A2 inhibitor, has been studied for its ability to inhibit gastric secretion and to protect the gastric and duodenal mucosa against chemically and stress-induced ulcers. Acid secretion studies were undertaken in pylorus-ligated rats with and without quinacrine treatment. Experimental gastric lesions were induced by water-immersion restraint stress, indomethacin and 80% ethanol in rats; whereas duodenal ulcers were produced by treatment of rats with cysteamine. The level of nonprotein sulfhydryl compounds and gastric wall mucus were also measured in the glandular stomach of the rats following ethanol-induced gastric lesions. The results of this study demonstrate that quinacrine produces a dose-dependent inhibition of gastric acid secretion in rats. Pretreatment with quinacrine significantly attenuated the formation of stress-, indomethacin- and ethanol-induced gastric lesions. Quinacrine also protected intestinal mucosa against cysteamine-induced duodenal ulcers. The antiulcer activity of quinacrine was associated with appreciable inhibition of ethanol-induced depletion of nonprotein sulfhydryls and gastric wall mucus. These findings point towards the mediation of sulfhydryls in quinacrine-induced gastrointestinal cytoprotection. In conclusion, this study demonstrates that quinacrine possesses significant antiulcer and cytoprotective activity against various experimentally induced gastroduodenal lesions. Although the mechanism of action of quinacrine requires further evaluation, the experimental observations derived from this study may have future clinical relevance and therefore deserve to be investigated thoroughly.