Objective:To evaluate the effect of Euphorbia fischeriana extract (EFE) on metastatic ability of melanoma B16 cells in vivo. Method: The B16 mouse transplanted tumor model and B16 spontaneous motility melanoma metastatic model were established

and C57BL/6 mice were randomly divided intocontrol group

group EFE 15.0

20.0 g·kg-1 and cyclophosphamide (CTX) group to detect the inhibition effect of EFE for growth of transplanted tumors and metastatic incidence on lung. The expression of phosphatase and tensin homolog deleted on chromosome ten (PTEN) and protein kinase B(p-Akt) of transplanted tumors were observed by immunohistochemical method. Result: EFE could inhibit the growth of B16 cells and the lung metastasis significantly in vivo. The growth inhibition rate of EFE when injected intrapetitoneally to mice at concentration of 15.0

20.0 g·kg-1 were 52.9% and 63.6% respectively (cyclophosphamide was 59.5%); inhibition rate of lung metastasis were 37.4% and 63.5% (inhibiton rate of cyclophosphamide was 56.8%). Immunohistochemical results indicated that compared with control group

expression of p-Akt in EFE group was less apparent while PTEN expression was more visible than control group. Conclusion: EFE could inhibit the metastasis of B16 cells in vivo

probably through down-regulating of p-Akt and up-regulating of PTEN expression

and further study are warranted.