Preventive and curative effects of curcumin on the development of gastric inflammatory diseases in rats

Preventive and curative effects of curcumin on experimental acute and chronic gastric ulcers were investigated to validate its clinical application on a remedy for peptic ulcer. Intraduodenal administration of curcumin, 5-20 mg/kg, inhibited gastric acid secretion in pylorus-ligated rats, and oral administration prevented ethanol-induced acute gastric mucosal lesions. Curcumin (20-80 mg/kg, p.o.) dose-dependently prevented both serotonin-induced gastric mucosal lesions and compound 48/80-induced gastric mucosal lesions in rats. Furthermore, oral administration of curcumin, 10-80 mg/kg, twice daily for 10 days, significantly accelerated the healing of acetic acid-induced chronic gastric ulcer and promoted mucosal regeneration in the ulcerated portion in a dose-related manner. Cimetidine prevented the formation of ethanol-induced gastric mucosal lesions, but not of serotonin-induced and compound 48/80-induced gastric mucosal lesions. Consecutive administration of cimetidine showed a marked acceleration in the healing of acetic acid-induced ulcer. Aminoguanidine, an inducible nitric oxide synthase (iNOS) inhibitor, showed anti-ulcerogenic effects similar to those oberved for curcumin. The present results indicate that curcumin exhibits gastric cytoprotection in the acute lesion models and ulcer healing promotion in the chronic ulcer model. The preventive and curative effects of curcumin might be due to an increase in the mucosal defensive mechanism through its antioxidant property and inhibition of NO or cytokine-mediated inflammation.