Objective:To explore the effects of Zhiyan mixture on the activation of classically activated macrophages(M1)and T helper cells 2(Th2)immune responses in mice with mycoplasma pneumoniae(MP)infection.Methods:C57BL/6J mice were divided into control group,MP group,Zhiyan mixture group and azithromycin group.Except control group,models of MP infection were prepared by nasal drip of MP bacterial solution(1×107 CFUs/ml)in the other groups.Zhiyan mixture group was given intragastric administration of Zhiyan mixture,azithromycin group was given intragastric administration of azithromycin,control group and MP group were given the same volume of normal saline.The pathological damage of lung tissues were observed by HE staining,and patho-logical scoring was conducted.The changes of MP load in lung tissues were detected by solid culture method.M1 level was detected by flow cytometry.The mRNA levels of inducible nitric oxide synthase(iNOS),TNF-α and CXC chemokine 1(CXCL1)in lung tissues were detected by PCR.The levels of IL-4,IL-5,IL-10 and IL-13 in lung tissues were detected by ELISA.The expressions of NF-κB pathway-related proteins in lung tissues were detected by Western blot.Results:The pathological scores of lung tissues,MP load,F4/80+cell level,ratios of CD86+/F4/80+and MHC Ⅱ+/F4/80+,and mRNA levels of iNOS,TNF-α and CXCL1 in MP group,Zhiyan mix-ture group and azithromycin group were higher than those in control group(P<0.05),levels of IL-4,IL-5,IL-10 and IL-13,and ex-pressions of p-p65/p65 and p-IKK/IKK in lung tissues were all higher than those in control group(P<0.05).The pathological scores of lung tissues,MP load,F4/80+level,ratios of CD86+/F4/80+and MHC Ⅱ+/F4/80+,and mRNA levels of iNOS,TNF-α and CXCL1 in Zhiyan mixture group and azithromycin group were lower than those in MP group(P<0.05),levels of IL-4,IL-5,IL-10 and IL-13 were higher than those in MP group(P<0.05),and protein expressions of p-p65/p65 and p-IKK/IKK in lung tissues were lower than those in MP group(P<0.05).Conclusion:Zhiyan mixture can improve lung injury in mice with MP infection,which may be related to reducing M1 activity,increasing Th2 immune response and inhibiting NF-κB pathway.