Fig. 7.

Long-term exposure to curcumin decreases cell viability and induces apoptosis in HEK293 Phoenix cells in a dose-dependent manner. The pro-apoptotic effect of long-term exposure (19 h in a complete medium) to 0.1–10 μM curcumin was investigated on HEK293 Phoenix cells by flow cytometry. Control cells were incubated with 0.05% DMSO. (a) Original dot plots of the 7-AAD versus the Annexin-V/FITC fluorescence intensities (logarithmic scales). 7-AAD negative/Annexin-V negative cells were considered as non-apoptotic, non-necrotic (lower left quadrant, viable cells), 7-AAD negative/Annexin-V positive cells as early apoptotic (lower right quadrant), 7-AAD positive/Annexin-V positive cells as late apoptotic (upper right quadrant), and 7-AAD positive/Annexin-V negative cells as post-late apoptotic/necrotic (upper left quadrant). Bar diagrams show the percentages of (b) necrotic, (c) late apoptotic, (d) non-apoptotic, non-necrotic (viable), and (e) early apoptotic cells. *p < 0.05, **p < 0.01, one way ANOVA with Dunnet's post-test. Data were collected from 6 independent experiments.