BackgroundKejinyan decoction, as an experienced formula of Zhou Zhongying (the Master of Traditional Chinese Medicine) has been widely used in clinic for lung cancer treatment in China, while the anti-lung cancer mechanism of it is still remained to be elucidated. Herein, our basic study found that the survival of lung cancer xenograft mice was significantly prolonged after intragastrically administered high dose of Kejinyan decoction (3.8 g per kg BW) for 15 days. More importantly, we found that Kejinyan decoction inhibited the metastasis of lung cancer cells in vivo. Thus in this study, we aim to elucidate the anti-metastasis effects of Kejinyan decoction.MethodsRNA-Seq was used to find out the gene regulation of Kejinyan decoction on the mice, flow cytometry assay was used to detect the immunocytes in the spleen, ELISA assay was used to detect the inflammatory factors in the serum and spleen, and immunofluorescence assay was used to detect the level of immune cells and the expression of glycol-metabolism related enzymes in situ. Also, we established a lung cancer orthotopic xenograft tumor model to assess the influence of Kejinyan decoction on the metastatic ability of lung cancer cells in vivo.ResultsGO analysis of gene sequencing of tumor tissue samples showed that Kejinyan decoction regulated immune response. Further flow cytometry analysis of splenic lymphocyte showed that Kejinyan decoction upregulated M1 macrophages and downregulated M2 macrophages, while the total level of macrophages changed little, which was verified by detection of CD68, F4/80, CD206, and CD86 in tumor tissue section. Moreover, detection of inflammatory cytokines showed that Kejinyan decoction downregulated TNF-α, IFN-γ, IL-6, as well as IL-4, IL-13 in tumor microenvironment. Further studies also showed that Kejinyan decoction had little effect on tumor hypoxia, but downregulated glycolysis in tumor tissues. More importantly, we found that Kejinyan decoction inhibited the metastasis of lung cancer cells in vivo.ConclusionOur findings conclude that Kejinyan decoction inhibited lung cancer cell metastasis through affecting macrophage polarization and energy reprogramming.