Figure 2.

Effects of curcumin on G₂/M cell cycle arrest and apoptosis in U87 cells. (A) U87 cells were left untreated (control) or were treated with 20 or 40 µM curcumin for 24 h. Subsequently, the cells were harvested and stained with propidium iodide (PI), in order to determine cell cycle distribution by flow cytometry. (B) Effects of curcumin on apoptosis were analyzed by flow cytometry using Annexin-V-fluorescein isothiocyanate (FITC) and PI. (C) After U87 cells treated with 20 or 40 µM curcumin for 24 h, total proteins were collected. Cell cycle-related proteins cyclin-dependent kinase 1 (CDK1) and cyclin G2 were determined by western blotting. (D) Western blotting was conducted to detect the expression levels of apoptotic proteins cleaved caspase-3 and Fas ligand (Fas)L. GAPDH, glyceraldehyde 3-phosphate dehydrogenase.