Effect of curcumin, DBA, DBM, and DBP on cell proliferation. (A) Five thousand KBM-5, Jurkat, MDA-MB-231 and DU145 cells per well were seeded in triplicate onto 96-well plates and treated with each compound at 1, 5, 10, 25, 50, 100, or 200 μM for 72 h. Cell viability was then measured by the MTT method and presented as percent cell viability. (B) The percent change in cell viability at 25 and 50 μM for each compound is shown. The results are expressed as the mean ± standard error of 3 independent experiments.