Cell Apoptosis Assay
Cells were seeded in the 6-well plates at a density of 1x106cells/well and after 24 hrs, treated with increasing concentrationsof PP (based on IC50values)for 24 hrs. Cells were then harvested and stained using the PE Annexin V apoptosis detection kit to identify apoptotic cells according to the manufacturer’s instruc-tions followed by flow cytometry. This assay was used to quantify viable cells, early apoptotic cells and late apoptotic cells.Percentage of cell population in apoptosis was calculated using Mod Fit LT software (Verity Software House, Topsham, ME).