Fig. 1

Effect of tectochrysin on cell growth and apoptotic cell death in colon cancer cells. a Concentration-dependent effect of tectochrysin on the cell growth in SW480 and HCT116 cells. After treatment of tectochrysin (1, 5 and 10 μg/mL) for 72 h, the effect of tectochrysin on colon cancer cell growth was determined by MTT assay and morphologic observation. b Concentration-dependent cell growth inhibitory effect of tectochrysin in CCD-18co normal colon cell. After treatment of tectochrysin (1, 5 and 10 μg/mL) for 72 h, the cytotoxicity effect of tectochrysin on normal colon cell viability was determined by MTT assay. c The colon cancer cells were treated with tectochrysin (1, 5 and 10 μg/mL) for 24 h, and then labeled with TUNEL solution. The green color in the fixed cells marks TUNEL-labeled cells. Total number of cells in a given area was determined by using DAPI nuclear staining (fluorescent microscope). The apoptotic index was determined as the DAPI-stained TUNEL-positive cell number/total DAPI-stained cell number (magnification, 200x). These data are expressed as the mean ± SD of three experiments. *P < 0.05 indicates statistically significant differences from the control group