Melatonin reduces inflammatory injury through inhibiting NF-kappaB activation in rats with colitis.

Proinflammatory mediators are important in the pathogenesis of IBD, which are regulated by activation of NF-kappaB. The aim of this study was to investigate whether melatonin reduces inflammatory injury and inhibits proinflammatory molecule and NF-kappaB in rats with colitis. Rat colitis model was established by TNBS enema. NF-kappaB p65, TNF-alpha, ICAM-1, and IkappaBalpha in colon tissue were examined by immunohistochemistry, EMSA, RT-PCR, and Western blot analysis. Expression of proinflammatory molecule and activation of NF-kappaB were upregulated and IkappaB level decreased in rats with colitis. Melatonin reduces colonic inflammatory injury through downregulating proinflammatory molecule mediated by NF-kappaB inhibition and blockade of IkappaBalpha degradation.