Zinc l-carnosine protects colonic mucosal injury through induction of heat shock protein 72 and suppression of NF-κB activation

In this study, we investigated the effects of zinc l-carnosine, an anti-ulcer drug, on acetic acid-induced colonic mucosal injury and the correlation of these effects with expression of 72-kDa heat shock proteins (HSP72) and nuclear factor kappa B (NF-κB) activation in rat colonic mucosa in vivo. After intrarectal administration of zinc l-carnosine, the rats received intrarectal infusion of 5% acetic acid (1 ml). The colonic mucosal damage was evaluated by macroscopic assessments 24 h after the intrarectal infusion of acetic acid. Expression of HSP72 in rat colonic mucosa was evaluated by Western blot analysis before and after zinc l-carnosine administration. NF-κB activation was evaluated by electrophoretic mobility shift assays (EMSA). Zinc l-carnosine inhibited visible damage in rat colonic mucosa by acetic acid. Expression of HSP72 was significantly increased at 6 h after zinc l-carnosine administration. Furthermore, NF-κB activation in colonic mucosa was suppressed 6 h after zinc l-carnosine treatment. These results suggested that zinc l-carnosine protects the colonic mucosa against acetic acid by induction of HSP72 and suppression of NF-κB activation and zinc l-carnosine may be a novel therapeutic agent for the therapy of inflammatory bowel disease.