Mechanism of Chaishao Liujunzi Tang in Treatment of Ulcerative Colitis Through TLR4/MyD88/NF-κB Signaling Pathway / 中国实验方剂学杂志

ABSTRACT

ObjectiveTo investigate the preventive and curative effect of Chaishao Liujunzi Tang （CSLJZT） on colonic mucosal injury induced by dextran sulfate sodium （DSS） in mice with ulcerative colitis （UC） and its mechanism. MethodFifty Balb/c male mice were randomly divided into normal group， model group， CSLJZT low-dose group， CSLJZT high-dose group， and sulfasalazine group. Except for the normal group， other groups were given 2.5% DSS freely for 7 d， and were given drug intervention after successful modeling for 7 d. Bodyweight， feces， and other general physiological statuses of mice were recorded every day， and disease activity index （DAI） scores were calculated.The colon length was measured， and stained by hematoxylin-eosin （HE） staining to observe the morphological changes of the colon.The enzyme-linked immunosorbent assay （ELISA） was used to determine the content of interleukin-1β （IL-1β）， myeloperoxidase （MPO）， and superoxide dismutase （SOD） in the serum. Western blot was used to determine the protein expression levels of Toll-like receptor 4 （TLR4）， myeloid differentiation factor 88 （MyD88）， nuclear factor kappa B （NF-κB）， inhibitor-kappa binding protein （IκB）， Caspase-1， and nucleotide-binding oligomerization domain-like receptor 3 （NLRP3） in the colon tissues. ResultAs compared with the normal group， mice in the model group had significantly decreased body weight （P<0.01）， severe diarrhea and hematochezia， and significantly increased DAI score （P<0.01）. As compared with the model group， the decreasing trend of body weight was significantly alleviated in the CSLJZT groups （P<0.01）， diarrhea and hematochezia were significantly improved， DAI score was significantly decreased （P<0.01）， and colon length increased （P<0.05）. HE staining showed that the pathological damage of colon tissue was significantly improved and the inflammatory cell infiltration was reduced in the CSLJZT groups as compared with the model group. As compared with the normal group， the serum levels of IL-1β and MPO were significantly higher （P<0.01） and SOD levels were significantly lower （P<0.01） of mice in the model group.Compared with the model group， the treated group reduced the serum IL-1β and MPO levels （P<0.01）， and raised the SOD level （P<0.01）. The results of Western blot showed that as compared with the normal group， the expression levels of TLR4， MyD88， NF-κB， Ccaspase-1， and NLRP3 proteins were significantly increased （P<0.01）， whereas the expression level of IκB protein was significantly decreased （P<0.01） in the colonic tissue of mice in the model group. As compared with the model group， the expression levels of TLR4， MyD88， NF-κB， Caspase-1， and NLRP3 proteins were decreased （P<0.01）， whereas the expression level of IκB protein was increased （P<0.01） in the colonic tissue of mice in the CSLJZT groups. ConclusionCSLJZT improves the inflammatory injury of the colon tissue in DSS-induced UC mice through TLR4/MyD88/NF-κB signaling pathway.