The Effect of the Cholinergic Anti‐Inflammatory Pathway on Experimental Colitis

Abstract Inflammatory bowel diseases (IBD) are characterized by proinflammatory cytokines, tissue damage and loss of neuron in inflamed mucosa, which implies the cholinergic anti‐inflammatory pathway may be destroyed during the process of inflammatory response. In the study, we identified the effect of cholinergic agonist as anabaseine (AN) and nicotinic receptor antagonist as chlorisondamine diiodide (CHD) on trinitrobenzene sulfonic acid (TNBS)‐induced colitis, to investigate the potential therapeutic effect of the cholinergic anti‐inflammatory pathway on IBD. Experimental colitis was induced by TNBS at day 1, 10 μg AN or 1.5 μg CHD was injected i.p. to mouse right after the induction of colitis, and repeated on interval day till the mice were sacrificed at day 8. Colonic inflammation was examined by histological analysis, myeloperoxidase (MPO) activity, and the production of tumour necrosis factor (TNF)‐α in tissue. Lamina propria mononuclear cells (LPMC) were isolated, and NF‐κB activation was detected by western blot. The mice with colitis treated by AN showed less tissue damage, less MPO activity, less TNF‐α production in colon, and inhibited NF‐κB activation in LPMC, compared with those mice with colitis untreated, whereas the mice with colitis treated by CHD showed the worst tissue damage, the highest MPO activity, the highest TNF‐α level, and enlarged NF‐κB activation in LPMC. Agonist of the cholinergic anti‐inflammatory pathway inhibits colonic inflammatory response by downregulating the production of TNF‐α, and inhibiting NF‐κB activation, which suggests that modulating the cholinergic anti‐inflammatory pathway may be a new potential management for IBD.