Curcumin, garcinol and LTK-14 impede MCF7 cell proliferation. (A) MCF7 cells were seeded at a density of approximately 5 × 103 cells per well in microtitre plates and allowed to adhere overnight. The initial cell density was determined in a control plate prior to addition of curcumin, garcinol or LTK-14 at the indicated concentrations, or vehicle. After 24 hours, the change in the number of viable cells was estimated using MTT assays (see Methods). The data shown are the means of 5 replicates ± standard deviations. (B) Cell cycle analyses of MCF7 cells after 24 hours in culture in the presence of garcinol or LTK14 (10 μM) or vehicle control. The bar charts show a representative experiment indicating the percentage of cells in G1, S or G2/M phases, and the subG1 population as determined by BrdU incorporation and propidium iodide staining. (C) Cell cycle analyses of MCF7 cells after 24 hours culture in the presence of curcumin (10 μM or 20 μM) or vehicle control, as described in (B).