Antitumor Effect of Liu-Shen-Wan on Transplanted Tumors of Mice with Colon Cancer from Perspective of Tumor Microenvironment

Objective To investigate the effect of Liu-Shen-Wan on transplanted tumors in mice with colon cancer based on the polarization of M2 macrophages in the tumor microenvironment. Methods We established a subcutaneous transplantation tumor model of mice with CT26 colon cancer. Mice were randomly divided into vehicle, oxaliplatin, and oxaliplatin combined with Liu-Shen-Wan groups. Treatment was administered for three weeks, and tumor volume was measured. All mice were weighed during the administration. After the end of the treatment, the mice were dissected and tumors were photographed and weighed. Spleen index was calculated. The expression levels of IFN-γ and IL-12P40 in serum and related blood biochemical indices were measured. The expression levels of M2 macrophage polarization indices, namely, IL-10 and TGF-β, in serum and tumor tissues were detected. The infiltration degree of M2 macrophages in each group was observed by immunohistochemical experiments. Results The tumor volume and mouse weight in the oxaliplatin combined with Liu-Shen-Wan group significantly decreased compared with those in the vehicle group. The spleen index increased, and the expression levels of IFN-γ and IL-12P40 in serum also significantly increased. The mice had no obvious side effects after the drug treatment. In addition, the expression levels of IL-10 and TGF-β in the serum and tissues of mice in the oxaliplatin combined with Liu-Shen-Wan group significantly decreased. The expression levels of CD68 and CD206 in tumor tissues also decreased. Conclusion The anti-tumor effect of Liu-Shen-Wan on the transplanted tumors of mice with colon cancer is related to the inhibition of M2 macrophage polarization in the tumor microenvironment.