Acteoside, a phenylpropanoid glycoside with anti-oxidative activity, induced cell death in promyelocytic leukemia HL-60 cells with an IC50 value of 26.7/microM. Analysis of extracted DNA on agarose gel electrophoresis revealed that acteoside induced the internucleosomal breakdown of chromatin DNA characteristic of apoptosis. Apoptosis-specific DNA fragmentation was clearly detectable 4 h after treatment with acteoside and was independent of the cell cycle phase. These data indicate that acteoside induces apoptosis in HL-60 cells.