Colon-targeted celecoxib ameliorates TNBS-induced rat colitis: A potential pharmacologic mechanism and therapeutic advantages

The clinical usefulness of celecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor, for treatment of inflammatory bowel disease (IBD) is controversial in terms of efficacy and toxicity. To overcome these problems, colon-specific drug delivery was adopted, which generally confers therapeutic and toxicological advantages of drugs for treatment of colonic diseases. N-succinylaspart-1-yl celecoxib (SA1C), a colon-specific prodrug of celecoxib, was administered orally to rats with experimental colitis, and the anti-colitic effects and a molecular mechanism were investigated and compared to those of conventional celecoxib. SA1C, which delivered a much greater amount of celecoxib to the inflamed colon, alleviated the colonic injury, lowered myeloperoxidase activity in the inflamed colonic tissues and was much more effective than conventional celecoxib. SA1C but not conventional celecoxib significantly attenuated expression of NFκB target gene products in the inflamed tissues. Consistent with this, SA1C effectively prevented nuclear accumulation of p65 in the inflamed tissues. Moreover, while conventional celecoxib lowered the serum level of 6-keto-PGF_1α, an inverse indicator of cardiovascular toxicity, SA1C did not change its serum level. Our data suggest that colonic delivery of celecoxib is a feasible strategy for treatment of IBD with improved therapeutic and toxicological properties.