Figure 3: Dose responsive curve of the cytotoxic activity of serial double dilution of leech saliva extract, Irinotecan and Carboplatin on small cell lung cancer cell line SW127. *%concentration = (concentration / initial concentration) ×100. Cell viability after 5 days of incubation was determined using CellTiter-Glo® luminescent cell viability assay. Inhibition of proliferation is expressed as the mean of three separate riplicates ± SEM (n=3). IC50 was estimated by Four Parametric Logistic Equation using Sigma Plot 11.0 software.