Dose effects on cell proliferation in studies of TQ and DG combinations.

<p>(A) MTT assay of proliferation of cells treated with different concentrations of TQ and DG for 48 hours. Points represent means ± SEM of three different experiments. (B) Combination index (CI) was calculated; CI<1 suggests synergism between TQ and DG in A431 and Hep2 cells. Red crosses (1–4) represent the concentrations of TQ and DG in various combinations: 1 = 10 µM∶10 µM (TQ∶DG); 2 = 10 µM∶20 µM (TQ∶DG); 3 = 20 µM∶10 µM (TQ∶DG); and 4 = 20 µM∶20 µM (TQ∶DG).