Curcumin induced cell cycle arrest in medulloblastoma cells. A, DAOY cells were arrested in G1/S and the block was released in the presence of 0, 10 or 20 μM curcumin. At indicated time points cell cycle progression was analyzed by flow cytometry. B, Mitotically arrested DAOY cells were released from their block in the presence of 0, 10 or 20 μM curcumin. Cell cycle profiles were determined at the indicated time points. C, Unsynchronized cells were treated with indicated concentrations of curcumin for 12 h. G1/S-arrested DAOY cells were released from their block for 12 h in the presence of curcumin. To obtain G2/M arrested cells, DAOY cells were synchronized first at G1/S. The block was released for 8 h in the absence of any drugs. Cells were then treated with the indicated concentration of curcumin for an additional 12 h. The cell-cycle dependent cytotoxicity of curcumin was measured by an LDH assay. A-C, The data are the mean ± SEM of three independent experiments.