Apoptosis induced by tea polyphenols in HL-60 cells

In order to search for tumor cells apoptosis inducer, the apoptosis effects and mechanism of tea polyphenols were studied. Tea polyphenols are active compounds purified from tea. The apoptosis effects of tea polyphenols were observed on the human promyelocytic leukemic cells (HL-60) by an MTT reduction test, DNA agarose gel electrophoresis and a transmission electronic microscopy technique. After HL-60 cells were treated by tea polyphenols in 250 microg/ml for 5 h, DNA extracted from HL-60 cells showed a typical internucleosomal DNA degradation, i.e. DNA ladder and apoptotic vehicles were observed. The effects of tea polyphenols were shown to be similar to their cytotoxic activity in HL-60 cells. These results suggest that the mechanism of antitumor action of tea polyphenols is related to its apoptosis-inducing activity.