Effect of Jianpi Yichang Powder on NLRP3/ASC/Caspase-l Signaling Pathway in Rats with Ulcerative Colitis / 中国实验方剂学杂志

ABSTRACT

ObjectiveTo explore the effect of Jianpi Yichang power on the nucleotide-binding oligomerization domain-like receptor protein 3 （NLRP3） inflammasome signaling pathway in a rat model of ulcerative colitis （UC）. MethodSixty Sprague-Dawley rats were randomly divided into a normal group （n=10） and an experimental group （n=50）. The experimental group received 5% dextran sulfate sodium （DSS） solution freely for 7 days to induce UC， and then they were further randomly divided into model group， sulfasalazine （0.3 g·kg-1） group， and high-， medium-， and low-dose Jianpi Yichang power groups （54.4， 27.2， 13.6 g·kg-1） for continuous treatment of 14 days. The general condition of the rats was observed and recorded daily， and the disease activity index （DAI） was scored before and after treatment. Enzyme-linked immunosorbent assay （ELISA） was used to detect the levels of interleukin-1β （IL-1β） and interleukin-18 （IL-18） in the serum of rats in each group. Hematoxylin-eosin （HE） staining was performed to observe the histopathological changes in the colon tissue. Immunohistochemistry， Western blot， and Real-time polymerase chain reaction （Real-time PCR） were used to detect the positive protein expression， protein expression， and mRNA expression of NLRP3， apoptosis-associated speck-like protein containing a CARD （ASC）， and cysteine aspartate-special proteases-1（Caspase-1） in the colon tissue. ResultCompared with the condition in the normal group， the general condition of rats in the model group was relatively poor， with increased DAI scores （P<0.01）， pathological changes in the colon， increased levels of IL-1β and IL-18 in the serum （P<0.01）， and enhanced positive protein expression， protein expression， and mRNA expression of NLRP3， ASC， and Caspase-1 in the colon tissue （P<0.01）. Compared with the condition in the model group， the general condition of rats in the Jianpi Yichang power groups at various doses improved significantly， with reduced DAI scores （P<0.05， P<0.01）， alleviated pathological changes in the colon as revealed by HE staining， and reduced protein expression levels of NLRP3 and Caspase-1 in the colon tissue （P<0.05， P<0.01）. The serum levels of IL-1β and IL-18， and ASC protein expression in the colon， as well as the mRNA expression levels of NLRP3， ASC， and Caspase-1， decreased in the high- and medium-dose Jianpi Yichang power groups （P<0.05， P<0.01）. The positive protein expression levels of NLRP3， ASC， and Caspase-1 were reduced in the high-dose Jianpi Yichang power group （P<0.01）. The positive protein expression levels of ASC and Caspase-1 were reduced in the medium-dose Jianpi Yichang power group （P<0.05）. The mRNA expression level of ASC was reduced in the low-dose Jianpi Yichang power group （P<0.05）. ConclusionJianpi Yichang power can reduce colon immune inflammatory damage by regulating the NLRP3 inflammasome signaling pathway， thereby exerting a role in treating UC.