OBJECTIVETo investigate the effects of snakegourd root polysaccharide on apoptosis of human breast cancer cells (MCF-7 cells).

METHODSColorimetric MTT assay was used to measure the inhibition of snakegourd root polysaccharide on MCF-7 cells. The morphological changes of MCF-7 cells were observed by fluorescence microscope after DAPI staining and transmission electron microscope. The apoptosis of MCF-7 cells was examined by DNA agarose gel electrophoresis analysis of DNA fragmentation amd flow cytometry. The activity of Caspase-3 and Caspase-8 was detected by colorimetric assay.

RESULTSPolysaccharide of snakegourd root significantly inhibited MCF-7 cells in a dose-and time-dependent manner. The nuclear condensation and marginalization were observed by DAPI staining and transmission electron microscope. The characteristic ladder of apoptosis in DNA electrophoresis was detected in MCF-7 cells treated with 10.0 μmol/L polysaccharide of snakegourd root at d 2. The activities of Caspase-3 and Caspase-8 were increased in a time-dependent manner. The rates of apoptosis in MCF-7 cells were (5.2 ±1.3)%, (13.1 ±4.7)%, (27.6 ±6.8)% and (43.8 ±9.8)% treated with 1.0,5.0,10.0 and 20.0 μmol/L snakegourd root polysaccharide at d 2,respectively. The maximal activities of intracellular Caspase-3 and Caspase-8 were (2.32 ±0.12)U/μg and (1.92 ±0.11)U/μg at d 2 and d 1, respectively when MCF-7 cells were treated with 10.0 μmol/L.

CONCLUSIONThe polysaccharide of snakegourd root can induce the apoptosis of MCF-7 cells,which is associated with the activation of intracellular Caspase-3 and Caspase-8.