Induction of apoptosis in RS cells ex vivo treated for 24 hours with Duv, Ven, and their combination. (A) Percentage of viable RS cells after 24 hours’ treatment with vehicle (blue), Duv (red), Ven (green), and their combination (gray). Data are reported as mean ± SEM. (B) Expression levels of cleaved (Cl.) and total Caspase-3 and PARP1 in RS cells after 24 hours’ treatment with Duv, Ven, and their combination. Bar plots represent intensity of proteins bands in 5 independent experiments. Band intensities were measured using Image Lab, normalized on β-actin, and plotted as fold change (FC) over the band of vehicle treated cells. Data are reported as mean ± SEM. (C) CI analysis. CI was calculated using the Bliss Independence model to compute the effect of Duv and Ven combination. Synergistic effect is defined as CI < 1 (green), while additive effect is CI around 1 (black) and antagonist effect is CI > 1 (red). Statistical analysis was performed using 1-way ANOVA; *P < .05, **P < .01, ***P < .001, ****P < .0001.