Icariin inhibits tumor lung metastasis in vivo.
Because of the anti-metastasis effect of icariin in vitro , we subsequently established a pulmonary metastasis model of 4T1-Luciferase cells in Balb/c mice to evaluate the anti-metastatic efficacy of icariin in vivo . As shown in Fig. 7A and B, the bioluminescence representing metastatic tumor cells was obviously enhanced over time in comparison with the icariin treatment group. At 15 day after tumor inoculation, the bioluminescence signals of the mice in the 20 mg/kg treatment group (3369±223 p/sec/cm2/sr, P <0.005) and 40 mg/kg treatment group (5489±358 p/sec/cm2/sr,P <0.001) were significantly lower than that of the control group (8374±469 p/sec/cm2/sr). In addition, the number of metastatic nodules at lung sites of the 20 mg/kg treatment group (34.2±4.1,P <0.005) and 40 mg/kg treatment group (57.5±5.2, P <0.001) were significantly reduced in comparison with the control group (81.6±6.4) (Fig. 7C and D). Moreover, collected lung tissues were sectioned and analyzed by H&E staining to determine the anti-metastatic efficiency of icariin (Fig. 7E). H&E staining of these tissue sections indicated that fewer tumor nodules were present in the icariin treatment group compared with the control group. These results implied that icariin could effectively inhibit 4T1 tumor pulmonary metastasis.