(A) GBC-SD and SGC996 cells were treated with varying concentrations of baicalein, and the cell proliferation were determined by MTT assay on days 1, 2, and 3. Each value represents the mean ± SD (n = 3). (B and C) Baicalein suppressed colony formation of GBC-SD and SGC996 cells. Cells were treated with baicalein (6, 12, and 24 μmol/L) and were allowed to form colonies in fresh medium for 14 days. The influence of colonies (mean ± SD, n = 3) in colony formation are shown. (D) Baicalein-treated xenograft tumors were much smaller than control tumors. (E) The weight of tumors revealed that xenograft tumor growth in nude mice was significantly slower in baicalein-treated nude tumors than control tumors. The results shown are representative of at least three independent experiments. *P < 0.05, **P < 0.01, ***P < 0.001.