To perform these assays, we purchased Pierce LDH Cytotoxicity Assay Kit from Thermo Scientific for 1000 reactions. We had grown the human alveolar epithelial cells (A549 cells) in Ham's F12 medium complemented with 10% FCS (fetal calf serum). We used 12-well plates and cultivated with 1 × 10 5 cells per well. Next, PLY (15 nM) + increasing concentrations of inhibitors were incubated for 4 h and 24 h (h = hours) at 37° C. Cells with media and 5 % triton X-100 samples were kept as negative and positive controls, whereas PLY alone and inhibitor (highest concentration) alone samples were regarded as PLY and inhibitor controls respectively. After incubation time, cellular supernatants of each sample were removed, centrifuged at 2000 RPM for 10 min at 4° C.