AST downregulates pro-angiogenic factors in HCT 116 colon cancer cells. (A) HCT 116 cells were treated with AST (80 μg/ml) and Western blotting was performed to analyze the level of bFGF and VEGF in a 72-hour time course study. (B) Various concentrations of AST (0, 40, 60 or 80 μg/ml) were administered to HCT 116 cells for 24, 48 or 72 h to determine its concentration-dependent effect on bFGF and VEGF level. Representative immunoblots from at least three independent experiments are shown. Relative band densities were summerized in histograms after normalization by β-actin. Arbitrary data are expressed as mean ± S.E.M., with statistical significance * p < 0.05, ** p < 0.01 when compared with the untreated group at 0 h (A) or the respective control group (B).