Untreated cells served as control. Cells from test and controls were harvested using trypsin phosphate versene glucose (TPVG) (HiMedia, Mumbai, India) at each mentioned time points. Resultant cell suspension was then admixed with 0.4% Trypan blue dye (HiMedia, Mumbai, India) and counted in Neubauer chamber and viable cells were estimated by the following formula [19