Figure 2.

Combination Indices (CI) were calculated from data of MTT assays (Figure 1) and plotted against the fraction affected (Fa) of A-427, BHY, KYSE-70, RT-4 and SISO cells after combination of different concentrations of mTHPC with either CDDP, CBDCA, or 1-OHP for the determination of synergism. CI values below the plotted line at 1.0 indicate synergistic effects by the combined compounds, whereas values > 1.1 indicate antagonistic effects according to the Chou-Talalay method [23].