Dose-effect response curves for Dox, rhoifolin, and their combination (Comb). A 1:2 Dox-to-Rhoifolin ratio B 1:4 Dox-to-rhoifolin ratio C 1:8 Dox-to-rhoifolin ratio. Combination index plots for 1:2 Dox-to-rhoifolin ratio (D), 1:4 Dox-to-rhoifolin ratio (E), and 1:8 Dox-to-rhoifolin ratio (F). The dose-effect curves and combination index plots were generated using CompuSyn software, with values representing the mean of three independent experiments. Color code: Green: combination of Dox and rhoifolin; Blue: Dox alone; Red: rhoifolin alone.