Effect Of Cold Stimulation On Asthmatic Mice Induced By House Dust Mite And Intervention Mechanism Of Qufeng Xuanfei Decoction

OBJECTIVETo investigate the effect of cold stimulation on the expression of inflammatory cytokines and TRPM8 in asthmatic mice induced by house dust mites and the intervention effect of Qufeng-Xuanfei decoction.METHODS40 male BALB/c mice were randomly divided into 5 groups,namely control group,cold stimulation group,HDM group,model group and Qufeng-Xuanfei decoction group,with 8 in each group.BALB/c mice were sensitized thrice with house dust mite intraperitoneally(ip),one week apart,and challenged with HDM intranasally(in)on three consecutive days in the third week.Cold stimulation was operated after the HDM challenge using a homemade device.Mice were treated with QXD intragastrically(ig)daily from the beginning to the end of the experiment.Interleukin(IL)-4,IL-5,IL-13,interferon(IFN)-y in bronchoalveolar lavage fluid(BALF),immunoglobulin E(Ig E)titers in serum,eosinophils(EOS)count in blood,lung and airway inflammation and the expression of transient receptor potential melastatin 8(TPRPM8)in lung tissues were finally assessed.RESULTS(1)Compared with the control group,the mean level of IL-4,IL-5,IL-13 and IFN-γ in BALF,eosinophil counts in blood and Ig E titers were increased in the cold stimulation group,but there was no statistical difference.Results of pathological HE staining and TRPM8 expression in Western blotting and immunohistochemistry in the cold stimulation group show no significant difference.(2)Compared with the control group,the mean level of IL-4,IL-5,IL-13,IFN-γ in BALF was significantly higher(P<0.0001,P<0.0001,P<0.05,P<0.0001),and eosinophil counts in blood,Ig E titers were increased(P<0.01,P<0.001),in model group.The pathological results showed that the epithelium of mucociliary epithelium was incomplete,the alveolar space was thickened and widened,and there were a large number of inflammatory cells infiltrated.WB and immunohistochemical results showed that the expression of TRPM8 in lung tissue increased(P<0.05).(3)Compared with the HDM group,mean level of IL-4,IL-5,IFN-γ in the BALF,eosinophil counts,and Ig E concentrations of the model group increased,but the results showed no statistical difference;IL-13 concentrations were increased,and the results showed no statistical difference,either;Results of HE staining,Western Blotting and immunohistochemistry showed no significant difference.(4)Compared with the model group,the level of IL-4,IL-5,IFN-γ in BALF,eosinophil counts and Ig E concentrations of the Qufeng-Xuanfei decoction group decreased significantly(P<0.05,P<0.05,P<0.01,P<0.01,P<0.01),but for IL-13 the decoction showed no obvious inhibition advantage;HE staining showed that the infiltration of inflammatory cells in lung tissue decreased,and the degree of pathological changes decreased significantly;Results of Western Blotting and immunohistochemistry showed that the expression of TRPM8 in lung tissue decreased significantly(P<0.05).CONCLUSION(1)Cold stimulation won’t cause asthma along,but exposure to a cold stimulus may aggravate symptoms of asthma.(2)Qufeng-Xuanfei decoction can down-regulate the expression of TRPM8 in the lung tissues of mice,regulate the type 2 immune response,improve the inflammatory infiltration of lung tissues,and relieve allergic asthma.