Abstract: Objective The effect of Asperosaponin Ⅵ（ASAⅥ）on adipocyte differentiation and the involvement of Wnt signal pathway was investigated. Methods The murine bone marrow stromal cell line ST- 2 were divided into 6 groups: control group, adipocyte differentiation group, and 4 different doses of ASAⅥ groups. Control group was exposed to the vehicle, adipocyte differentiation group was exposed to adipogenic reagent, and those 4 ASAⅥ groups were treated with different concentration（10-7, 10-6, 10-5, 10-4 mol/L）of ASAⅥ after adipocyte differentiation induction. 5 days later, oil red O staining was performed to calculate adipocyte rate. Then mRNA transcription levels of PPARγ, FABP4 genes and β-catenin that were Wnt/β-catenin signaling pathway proteins were examined by FQ-PCR. Then Wnt pathway inhibitor DKK1 was supplemented into ST-2 cells treated with 10-4 mol/L ASAⅥ for 5 days. After that FQ-PCR was used to detect whether tran⁃ scription levels of PPARγ, FABP4 and β-catenin in ST-2 cells were changed. Results Compared with adipocyte differenti⁃ ation group 10-5 mol/L and 10-4 mol/L ASAⅥ treatments greatly down-regulated the number of lipid droplets and markedly inhibited transcription levels of adipocyte characterization transcription factors included PPARγ, FABP4 while up-regulat⁃ ed transcription level of β-catenin in ST-2 cells. DKK1 can reverse the inhibitory effect of ASAⅥ on adipocyte differentia⁃ tion in ST-2 adipocyte. The transcription levels of PPARγ and FABP4 were up-regulated significantly while transcription level of β-catenin was inhibited. Conclusion ASAⅥ blocks adipocyte differentiation in ST-2 cells which might be medi⁃ ated through activating Wnt/β -catenin signaling pathway.

Key words: adipocyte differentitation, beta catenin, Asperosaponin Ⅵ, bone marrow stromal cells, Wnt signal pathway