The effect of indole-3-carbinol and sulforaphane on a prostate cancer cell line

Background: Cruciferous vegetable consumption is inversely related to the incidence of prostate cancer. We examined the effect of indole-3-carbinol (I3C) and of sulforaphane (constituents of cruciferous vegetables) on cell proliferation of a PC-3 prostate cancer cell line, in order to observe if an inhibitory effect might be detected in vitro . Methods: PC-3 prostate cancer cells were cultured in 96-well microtitre plates. Indole-3-carbinol concentrations ranging from 0.1 mmol/L to 0.8 mmol/L or sulforaphane concentrations ranging from 0.01 mmol/L to 0.06 mmol/L were added to the wells. Cell proliferation was measured by colorimetric assay and results were based on the mean value of triplicate experiments. Data are -presented as medians and interquartile ranges and were analysed using the Mann-Whitney U -test. Results: Cell proliferation in PC-3 prostate cancer cells was significantly inhibited by I3C and sulforaphane at media concentrations of 0.2 mmol/L and 0.02 mmol/L, respectively. Conclusion: Both compounds inhibited the proliferation of prostate cancer cells in a dose-dependant manner. These findings may help explain the observed protective effect of cruciferous vegetables in relation to prostate cancer.