British journal of pharmacology
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The effects of the inhibitors of glycogen synthase kinase-3beta (GSK-3beta), TDZD-8 and SB 415286, which can substantially reduce the systemic inflammation associated with endotoxic shock in vivo, have now been investigated on the acute colitis provoked by trinitrobenzene sulphonic acid (TNBS) in the rat. Administration of the GSK-3beta inhibitor TDZD-8 (0.1, 0.33 or 1.0 mg kg-1, s.c., b.i.d., for 3 days) caused a dose-dependent reduction in the colonic inflammation induced by intracolonic TNBS assessed after 3 days, both as the area of macroscopic involvement and as a score using 0-10 scale. Likewise, following administration of the GSK-3beta inhibitor SB 415286 (0.1, 0.33 or 1.0 mg kg-1, s.c., b.i.d., for 3 days), the extent and degree of the TNBS-provoked colonic inflammation was reduced. ⋯ The elevated levels of the transcription factor NF-kappaB subunit p65, as determined by Western blot in the nuclear extracts from the TNBS-provoked inflamed colonic tissue, were dose-dependently reduced by TDZD-8 or SB 415286 treatment. These findings demonstrate that two chemically distinct selective inhibitors of the activity of GSK-3beta reduce the inflammation and tissue injury in a rat model of acute colitis. The mechanisms underlying this anti-inflammatory action may be related to downregulation of NF-kappaB activity, involved in the generation of proinflammatory mediators.