Cell viability (Trypan blue dye exclusion assay)
For cell viability assays, the trypan blue dye exclusion method was used to evaluate the potential of direct cytotoxic effect of inhibitors on cells. After incubation for 24 hours, the cells were harvested and the percentage cell viability was calculated with the formula 100 × (number of viable cells/number of both viable and dead cells) [21].