Objective:To investigate the effect of verbascoside (VB) on epithelial-mesenchymal transformation and its potential molecular mechanism in glioblastoma cells.Methods:(1) Glioblastoma cell lines T98 and U251 were routinely cultured in vitro. Cells were divided into 4 groups and treated with 0 μmol/L (controls), 20 μmol/L, 40 μmol/L, and 80 μmol/L VB for 24 h, respectively; CCK-8 was used to detect the cell viability; Transwell assay was used to evaluate the migration and invasion abilities; reverse transcription (RT)-PCR and Western blotting were conducted to examine the mRNA and protein expressions of transforming growth factor (TGF)-β, vimentin and Snail, respectively. (2) T98 and U251 cells were divided into 4 groups: control group (cells being transfected with empty plasmid), VB group (cells being transfected with empty plasmid and treated by 40 μmol/L VB), TGF-β group (cells being transfected with TGF-β overexpression plasmid), TGF-β+VB group (cells being transfected with TGF-β overexpression plasmid and treated by 40 μmol/L VB); CCK-8 was used to detect the cell viability; Transwell assay was used to evaluate the migration and invasion abilities; RT-PCR and Western blotting were conducted to examine the mRNA and protein expressions of TGF-β, vimentin and Snail, respectively. (3) U251 cells were implanted subcutaneously into the nude mice; the mice were divided into VB group and control group ( n=8). The mice in the VB group were intraperitoneally injected with 100 mg/kg/d VB, and mice in the control group were injected with the same volume of PBS. Tumor size and mice body mass were recorded. At the end of the experiment, mice were sacrificed; tumors were removed and weighed. The protein expressions of TGF-β, vimentin and Snail in tumor tissues were detected by Western blotting. Results:(1) As compared with that in the 0 μmol/L VB group, the cell survival rate in the 20 μmol/L and 40 μmol/L VB group showed no significant difference ( P>0.05), while that in the 80 μmol/L VB group showed significant difference ( P<0.05). As compared with that in the 0 μmol/L VB group, the cell number migrating and invading into the lower chamber in the 20 and 40 μmol/L VB groups was significantly smaller as concentration increased, and the mRNA and protein expressions of TGF-β, Snail and vimentin were also downregulated successively, with signficant differences ( P<0.05). (2) As compared with the control group, the cell number that migrating and invading into the lower chamber, and protein expressions of TGF-β, vimentin, and Snail in the VB group were significantly decreased ( P<0.05); while as compared with the control group, the cell number that migrating and invading into the lower chamber, and protein expressions of TGF-β, vimentin, and Snail in the TGF-β group were significantly increased ( P<0.05); as compared with those in the VB group, the cell number that migrating and invading into the lower chamber, and protein expressions of TGF-β, vimentin, and Snail in the TGF-β and TGF-β+VB groups were significantly increased ( P<0.05). (3) As compared with the control group, the tumor volume and tumor weight in the VB group were statistically decreased, and the TGF-β, vimentin and Snail protein expressions in the VB group were significantly downregulated ( P<0.05); however, there was no significant difference in mice body weight between the two groups ( P>0.05). Conclusion:VB inhibits epithelial-mesenchymal transformation in glioblastoma by suppressing the TGF-β expression.