Gypenosides (Gyp) are extracted from Gynostemma pentaphyllum Makino that had been used as folk medicine in Chinese population. Gyp have been shown to induce cell death and apoptosis in many human cancer cell lines, such as colon, cervical and liver cancers. However, there is no available information to address Gyp induced apoptosis in HL-60 and WEHI-3 cells. We examined the effects of Gyp on human leukemia HL-60 and mouse WEHI-3 cells. Therefore, the results from flow cytomertic analysis indicated that Gyp arrest cell cycle in G0/G1 and induced apoptosis in both examined cell lines. We also used DAPI stain and DNA gel electrophoresis to confirm Gyp induced apoptosis in both cell lines. Flow cytometric also used for analysis the levels of reactive oxygen species, Ca2+ and mitochondrial membrane potential (MMP) in both cell lines. The results showed Gyp promoted ROS and Ca2+ production and decreased the MMP level. Western blotting show that Gyp treatment gradually decreased the levels of anti-apoptotic protein (Bcl-2), but increased the levels of the pro-apoptotic protein (Bax). Gyp promoted the release of cytochrome c from mitochondia based on the changes of MMP and the activation of caspase-3 before leading to apoptosis. We also used confocal laser microscope to show AIF and Endo-G are released from mitochondrial then move to nuclei
