Objective To investigate the effect of saikosaponin-d(SSd)on the expressions of STAT3 and COX-2 in hepatocellular carcinoma cells,and explore the underlying signal pathway mechanism of its anti-tumor effect.Methods MTT assay was used to detect the effect of SSd on the proliferation of cultured human hepatocellular carcinoma SMMC-7721 cells.Then the cells were divided into control,IL-6 group,AG490 group and SSd group,which were treated respectively with IL-6 25 ng/ml,IL-6 25 ng/ml+AG490 50 μmol/L,and IL-6 25...