Abstract: AIM: To study the apoptosis-inducing effect of podophyllotoxin nanoliposome on human leukemia K562 cells.METHODS: The podophyllotoxin nanoliposome was prepared using a dried film-ultrasonic procedure.K562 cells were treated with different concentration of podophyllotoxin (POD) and podophyllotoxin nanoliposome(POD-nlip) in vitro.The cell proliferating activity was assessed with an MTT assay, and cell morphology and Annexin Ⅴ/PI staining were employed to determine apoptosis in K562 cells.RESULTS: The inhibitory effect of POD-nliPon K562 cells was much higher than that of POD, the 50% inhibitory concentration (IC50) at 24 h,48 h and 72 h was 0.71, 0.02 and 0.003 μg·ml^-1 , respectively,and 1.50, 0.12 and 0.05 μg·ml^-1 respectivelyfor POD.After treatment with 0.01 μg·ml^-1 PODnlipand POD for 24 h and 72 h, the apoptotic rates ofK562 cells detected by Annexin Ⅴ/PI staining were 91.1% and 92.7% for POD-nlip, and 63.4% and 66.8% for POD, respectively.At 72 h the cells mainly showed late apoptotic phenomenon.The cells showed typical apoptotic morphological changes in both POD-nlipand POD-treated cells.CONCLUSION: Compared with podophyllotoxin, podophyllotoxin nanoliposome has more significant inhibitory and apoptosis-inducing effect on human leukemia cell line K562 cells.

Key words: nanoliposome, podophyllotoxin nanoliposome, apoptosis, K562 cell