Figure 1.

Effect of betulin on the viability of colon cancer cells. (A) HCT116, (B) HT29 and (C) CCD 841 CoN cells were incubated with betulin (range, 0–100 µg/ml) for 72 h. Subsequently, an MTT assay was performed to determine cell viability. (D) A cell colony formation assay was performed by plating betulin-treated (10 µg/ml, 48 h) 5000 HCT116 and HT29 cells onto 12-well plates. Cells were stained with crystal violet for 14 days. Quantification of colony numbers in (E) HCT116 and (F) HT29 cells. Data are presented as the mean ± standard deviation from three independent experimental repeats. *P<0.01, **P<0.001 vs. untreated cells.