Cyclooxygenase inhibitors counteract pro-fibrotic signalling in experimental colitis through modulation of TGF-beta/SMAD network

Aims. Cyclooxygenase isoforms (COX-1, COX-2) have been implicated in the development of fibrosis at gastrointestinal sites. Under bowel inflammation, transforming growth factor beta (TGF-beta) has been identified as the main regulator of fibrotic remodelling. The present study investigated the effects of cyclooxygenase inhibitors on pro-fibrotic signalling mediated by the TGF-beta/SMAD pathway in experimental colitis. Methods. Colitis was induced in rats by intrarectal 2,4-dinitrobenzenesulfonic acid (DNBS, 30 mg/rat in 0.25 ml ethanol 50%). After 6 days, systemic [body and spleen weight] and tissue inflammatory parameters [macroscopic and microscopic damage] were assessed. Three days befor…