Fig. 1

Evaluation of the biologic role of apigenin (API) in prostate cancer cell lines. a Four prostate cancer cell lines (LNCap, DU145, PC-3, and PC-3 M) were treated with various doses of apigenin or vehicle (DMSO) for 24, 48, and 72 h. Cell viability was determined by a CellTiter 96® cell proliferation assay. b A colony formation assay was performed with the four prostate cancer cell lines in the presence or absence of API. Colonies formed during 14 days of culture were visualized by crystal violet staining (left), and colony numbers were quantified by manual counting (right). c Representative images of wounded PC-3 M cells treated with or without 20 or 40 μM API for 48 h. Following incubation, migrated cells were stained with crystal violet (upper panel), and results of the quantitative analysis are expressed as the average number of migrated cells compared to controls (lower panel). d Cell migration and invasion determined by a transwell assay. Representative images of cell migration and invasion of PC-3 M cells with or without 20 or 40 μM of API treatment. All values are expressed as the multiple of change relative to the untreated control. Data are presented as the mean ± SD of at three independent experiments. * p < 0.05; ** p < 0.01; *** p < 0.001 compared to the vehicle group