Kaempferol induced apoptosis was associated with the cleavage of caspase-7 and PARP (poly ADP-ribose polymerase). Inhibition of MEK1/2 but not PI-3 kinase blocked kaempferol-induced cleavage of caspase - proteins are not sufficient for kaempferol to induce apoptosis and activation of MEK-MAPK is a requirement for kaempferol-induced cell death machinery in A549 cells.