3.9. Cell Viability Assay

Human lung adenocarcinoma cells (NSCLC, A549) were obtained from the National Center for Cell Science, Pune, India and maintained as per the method described by Goel et al., 2009 [34,35].

The cell viability was determined using the 3-(4,5-dimethyl thiazol-2yl)-2,5-diphenyltetrazolium bromide (MTT) assay. For this purpose, cells were grown in 96-well microtiter plates and treated with EA and EAPA separately at different concentrations (50–300 μM) in triplicates, for 24 h. Ethyl alcohol plus DMSO (100 μL) treated cells were taken as vehicle controls. In assay system, 100 μL MTT (5 mg/mL) was added to each well and incubated for 4 h at 37 °C in dark. Formazan crystals formed were dissolved in 100 μL ethyl alcohol plus DMSO and the absorbance was measured at 570 nm in an ELISA reader. Cell viability was calculated using the relationship: