RESUMO
Objective To investigate the therapeutic effects and mechanisms of Maxing Shigan Decoction on cough variant asthma(CVA)rats.Methods Sixty rats were randomly divided into normal group,model group,low and high dose groups of Maxing Shigan Decoction,and high-dose of Maxing Shigan Decoction + signal transducer and activator of transcription 3(STAT3)activator Colivelin(Col)group,12 rats in each group.Except for the normal group,the CVA model was constructed by intraperitoneal injection of ovalbumin combined with moxa fumigation in all other groups of rats.After the corresponding treatment,the rats were observed for signs and cough counts,airway resistance(RE)was detected by pulmonary function meter,eosinophils(EOS)were counted by Diff-Quik staining,histopathological features of the lungs and bronchial tubes were observed by hematoxylin-eosin(HE)staining method,and the lung tissues were detected by enzyme-linked immunosorbent assay(ELISA)for monocyte chemotactic protein 1(MCP-1),and tumor necrosis factor α(TNF-α),and the protein expression levels of interleukin 6(IL-6),STAT3,and transient receptor potential vanilloid-1 channel(TRPV1)were detected by Western Blot.Results Compared with the normal group,rats in the model group showed obvious asthma symptoms,severe inflammatory cell infiltration was seen in the lung tissue,bronchial epithelial cell necrosis,ciliated adhesion,mucus,and RE,EOS number,MCP-1 and TNF-α contents,and protein expression levels of IL-6,STAT3,TRPV1 were elevated(P＜0.05);compared with the model group,rats in the low-and high-dose groups of Maxing Shigan Decoction showed significant improvement in asthma symptoms,reduction in lung and bronchial injury,and dose-dependent reduction in RE,EOS number,MCP-1 and TNF-α contents,and protein expression levels of IL-6,STAT3,and TRPV1(P＜0.05);compared with the high-dose group of Maxing Shigan Decoction,the rats in the high-dose Maxing Shigan Decoction+Col group showed increased asthma,increased lung and bronchial injury,and increased RE,EOS number,MCP-1 and TNF-α contents,and protein expression levels of IL-6,STAT3,and TRPV1(P＜0.05).Conclusion Maxing Shigan Decoction can effectively improve cough variant asthma in rats,and its mechanism is related to the inhibition of IL-6/STAT3 signaling pathway and the high expression of TRPV1.