Excess proinflammatory
cytokines owing to the activation of NF-κB and NLRP3
inflammasome play the key role in
inflammatory bowel disease (IBD). Previously, we reported the anti-inflammatory activity of
carboxyamidotriazole (CAI) resulting from decreasing
cytokines. Therefore, we investigated the
therapeutic effects of CAI in
2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced rat
colitis and the involvement of CAI action with NLRP3
inflammasome and NF-κB pathway. CAI was orally administered to TNBS-induced
colitis rat. The severity of
colitis was assessed, and NLRP3
inflammasome, NF-κB pathway and
cytokines were determined. Our results showed that CAI significantly reduced
weight loss and disease activity index (DAI) scores in
colitis rats and alleviated the colonic macroscopic signs and pathological damage. In addition, the intestinal inflammatory markers and permeability index were markedly ameliorated by CAI treatment. The decreased levels of
tumor necrosis factor-α (TNF-α),
interleukin (IL)-1β,
IL-6,
IL-18 were also detected in the colon tissues of CAI-treated
colitis rats. Moreover, the activation of NLRP3
inflammasome in inflamed colon was significantly suppressed by showing an obvious reduction in the NLRP3 and activated caspase-1 levels. Furthermore, CAI reduced NF-κB p65 expression and IκBα phosphorylation and degradation in
colitis rats. Therefore, CAI attenuates TNBS-induced
colitis, which may be attributed to its inhibition of NLRP3
inflammasome and NF-κB activation, and down-regulation of proinflammatory
cytokines. These results provide further understanding of the intestinal anti-inflammatory effect of CAI and highlight it as a potential
drug for the treatment of IBD.