Fig. 1
The combined effect of fisetin (FIS) and paclitaxel (PTX) on the A549 cells. a The cells were treated with various concentrations of PTX (0.1, 0.2, 0.3, 0.4, 0.5 μM) and FIS (10, 20, 30, 40, 50 µM), either alone or in a fixed ratio of 1:100, for 24 h. Cell viability was determined by MTT colorimetric assay. Data are expressed as a percentage of the control. Symbols $ and # indicate statistically significant differences compared with FIS or PTX treatment alone, respectively (p < 0.05; Mann–Whitney U test). All values represent the mean ± standard deviation of six independent experiments. b Combination index plot (Fa–CI plot) for FIS and PTX co-treatment in A549 cells. CI values are plotted as a function of the fractional inhibition (fa) of cell viability/growth by computer simulation (CompuSyn software) from 0.1 to 0.95. Triangles represent CI values derived from the actual experimental points. CI < 1 designates synergism, CI = 1 indicates additivity (denoted by a dashed line), and CI > 1 represents antagonism