Figure 3.
(a) Antiproliferation effects of 4β‐(benzoyl‐thioureido)‐4‐deoxypodophyllotoxin (HY‐1) and etoposide (VP‐16) on different human cancer cells by MTT assay. Cells were treated with different concentrations of compounds for 72 h. The IC 50 values were calculated using the mean results of three separate experiments, expressed as the mean ± SD (μM). (b) Antiproliferation effects of HY‐1 and VP‐16 on human colon carcinoma HCT116 cells by BrdU ELISA. All data represent the mean ± SD from three independent experiments. *P < 0.05 versus blank control; **P < 0.01 versus blank control; #P < 0.05 versus positive control; ##P < 0.01 versus positive control (n = 5).