Subsequently, PLY solution was added to a final concentration of 15 nM or 0.8 µg/ml and the mixture was incubated for 10 min at 37° C. PBS alone, PLY alone and 10 % Triton X-100 samples were used as controls. In the next step, the blood cells (2.5 % of total assay volume) added to each sample and incubated for 15 to 20 min at 37° C. Followed by incubation, all samples were centrifuged at 9000 g for 2 min. Supernatants of every sample were isolated in a 96-well plate and absorption was measured at 543 nm in a spectrometer. The data were normalized and IC50 values were calculated by "log (inhibitor) vs. normalized responsevariable slope" curve fitting using Graphpad Prism 6 (software).