Electron microscopic evaluation of mitochondrial and apoptotic changes after treatment with curcumin or/and 5-FU in HCT116 and HCT116R cells in alginate beads. A: Alginate (*) cultures of HCT116 cells were either left untreated (Co.) or were treated with different concentrations of curcumin (5, 10 and 20 μM) or 5-FU (0, 0.01, 0.1 and 1nM) or a combination of curcumin (5 μM) and 5-FU (0.01, 0.1 and 1nM) in serum-starved medium for 14 days. Magnification: x5000, bar = 1 μM. B-C: Mitochondrial changes (MC) and apoptosis were quantified by counting 100 in HCT116 (B) and HCT116R cells (C) with morphological features of apoptotic cell death from 25 different microscopic fields and results presented are mean values with standard deviations from three independent experiments. Significant values were compared with the control and statistically significant values with p < 0.05 were designated by an asterisk (*) and p < 0.01 were designated by two asterisks (**).