Fig. 6

Activity of the combination of cisplatin and pirfenidone was determined using the CellTiter-Blue cell viability assay after a 72-h treatment in A549 cells (a) and H157 cells (b). Results were analyzed for synergism using the combination index (CI) method. A confidence interval of 0.1–0.3 indicated strong synergism, 0.3–0.7 indicated synergism, 0.7–0.85 indicated moderate synergism, 0.85–0.90 indicated slight synergism, and 0.90–1.10 indicated nearly additive