Effect of curcumin on cells at G₁/S phase of the cell cycle.

Curcumin arrests the cells at G₁/S phase of the cell cycle. U266 cells (2 × 10⁶/mL) were incubated in the absence or presence of curcumin (10 μM) for the indicated times. Thereafter, the cells were washed, fixed, stained with propidium iodide, and analyzed for DNA content by flow cytometry as described in “Materials and methods.”