Effect of pear (Pyrus communis L.) procyanidins on gastric lesions induced by HCl/ethanol in rats

Effect of pear procyanidins on ethanol-induced gastric ulcer in rats was investigated. In a preliminary experiment, the percentage of lesion area to total gastric surface area (ulcer index) increased with increases in ethanol concentration (40–80%) and the length of time after ethanol treatment (60–120 min). Migration of leukocytes, estimated by myeloperoxidase activity in mucosa, was involved in the occurrence of an ulcer, whereas expansion of the ulcer seemed to be due to leukocytes that had already migrated. Highly polymerized procyanidins extracted from ‘Winter Nélis’ pear fruit, orally administered (20 mg/rat) before 60% ethanol treatment, exhibited a high level of antiulcer capacity whereas chlorogenic acid alone seemed to have a negative effect. The trend of myeloperoxidase activity was similar to the trend of the ulcer index. A mixture of those polyphenols had a significant protective effect. The results suggest that the antiulcer effect of pear procyanidins may be due to their strong antioxidant activity.