基于NF-κB/IL-6信号通路阐释芍药汤治疗大肠湿热证溃疡性结肠炎大鼠的作用机制OA

Objective To investigate the intervention effect and underlying mechanism of Shaoyao Decoction on ulcerative colitis(UC)rats with large intestine dampness-heat pattern based on NF-κB/IL-6 signaling path-way.Methods A total of 54 SPF-grade male SD rats were selected,among which 9 rats were randomly assigned to a blank group,and the remaining 45 rats were used to establish UC models with large intestine dampness-heat pattern via a combined method consisting of damp-heat environment,high-fat and high-sugar diet,and dextran sulfate sodium(DSS).After model establishment,6 rats(1 from the blank group and 5 from the model rats)were selected proportionally to verify the success of modeling.The remaining 40 model rats were randomly divided into a model group,a positive drug group(mesalazine group),and low-,medium-and high-dose groups of Shaoyao Decoction,with 8 rats in each group.Each group was intragastrically administered the corresponding liq-uid medicine or an equal volume of distilled water for 14 consecutive days.The general conditions of rats in each group were observed during intervention.After intervention,body weight,disease activity index(DAI)and colon length of rats in each group were recorded.Hematoxylin-eosin(HE)staining was applied to observe colonic patho-logical lesions and evaluate tissue damage index(TDI).Enzyme-linked immunosorbent assay(ELISA)was used to detect serum levels of inflammatory factors including tumor necrosis factor-α(TNF-α),interleukin-9(IL-9)and interleukin-10(IL-10).Reverse transcription quantitative polymerase chain reaction(RT-qPCR)and Western blot were adopted to detect the relative mRNA and protein expression of nuclear factor-κB(NF-κB)and interleukin-6(IL-6)in colonic tissues for comparative analysis.Results Rat models of UC with large intestine dampness-heat pattern were successfully established in this experiment.Compared with the blank group,rats in the model group exhibited decreased body weight,elevated DAI scores,significantly shortened colons,damaged colonic mucosa with massive inflammatory infiltration and increased TDI scores.Serum levels of pro-inflammatory factors TNF-α and IL-9 were upregulated while anti-inflammatory factor IL-10 was downregulated,and mRNA and pro-tein expression of NF-κB and IL-6 in colonic tissues were markedly increased,with statistically significant differ-ences(P<0.05).After intervention,general conditions,intestinal symptoms and colonic pathological lesions of rats in all medication groups were improved to varying degrees,accompanied by decreased DAI and TDI scores,recovered colon length,reduced serum TNF-α and IL-9 levels,elevated IL-10 levels,and suppressed mRNA and protein expression of colonic NF-κB and IL-6(P<0.05).Therapeutic effect of Shaoyao Decoction is dose-dependent.The overall improvement efficacy of the high-dose group showed no significant difference compared with the mesalazine positive drug group(P>0.05)and was superior to that of the low-and medium-dose groups.Conclusion Shaoyao Decoction can effectively treat UC with large intestine dampness-heat pattern by inhibiting excessive activation of NF-κB/IL-6 signaling pathway,downregulating expression of pro-inflammatory-related genes and proteins,regulating balance between pro-inflammatory and anti-inflammatory factors,and alleviating inflammatory infiltration and tissue injury of colonic mucosa,with better intervention efficacy at high doses.