Fig. 3

The effect of fisetin (FIS) and/or paclitaxel (PTX) on apoptosis of A549 cells. a, b Annexin V/PI assay by image-based cytometry. The sum of the early and late apoptotic cells represented the total apoptosis. a, c, d, e The A549 cells were treated with 10 µM FIS and/or 0.1 µM PTX for 24 h. b In another set of experiment, the cells were treated with the combination of 10 µM fisetin and 0.1 µM paclitaxel for 30 h, followed by post-treatment incubation in a drug-free medium for the next 24 or 48 h. Real-time PCR measurement of c caspase-3, d Bax, e Bcl-2 mRNA expression in A549 cells. The expression was normalized to GAPDH and presented as a fold difference relative to a calibrator sample (untreated A549 cells; designated as 1). f Bcl-2/Bax ratio. Control cells (CTRL) were cultured under identical conditions, but without the addition of the tested agents. Asterisks represent statistically significant differences from control cells (p < 0.05; Mann–Whitney U test). Symbols ^$ and ^# indicate statistically significant differences compared with FIS or PTX treatment alone, respectively (p < 0.05; Mann–Whitney U test). The data are representative of five (a, b) or three (c–e) independent experiments and presented as mean and standard deviation