Abstract:Objective To investigate the effect and mechanism of emodin inducing the apoptosis of human bile duct carcinoma cell QBC939 in vitro. Methods The inhibition of cell proliferation was detected by MTT. The morphological changes of apoptotic cells were observed under fluorescence microscopy. The apoptosis rates and intracellular reactive oxygen species levels were detected by flow cytometry. The intracellular relative activities of caspase-9 and caspase-3 were tested through colorimetric method. Results Emodin inhibited cell proliferation of human bile duct carcinoma cell QBC939 in time-dose dependent fashion. Apoptotic cells displayed bright, nuclear presented divided leaves, debris and cell shrinkage under fluorescence microscopy. Treated with 30 µmol/L and 50 µmol/L emodin, the apoptosis rates of 24 hours were respectively 38.9%±9.07% and 67.09%±4.08% (P<0.05). The intracellular reactive oxygen species levels after 30 minutes treatment were 1.65±0.08 and 2.28±0.04 folds of the control group (P<0.05). Emodin could activate caspase-9 and caspase-3, leading to elevations of their activities (P<0.05). Conclusions Emodin inhibites cell proliferation of human bile duct carcinoma cell QBC939 through inducing apoptosis. The mechanismis associated withthe elevated levels of reactive oxygen species and the activation of caspase-9 cells and caspase-3.

Key words:Emodin,Apoptosis,Reactive oxygen species,Caspases