Experimental study of emodin inducing apoptosis of bile duct carcinoma cell QBC939

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 a set of edges 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 ± 0.04folds of the control group (P ＜ 0.05). Emodin could activate caspase-9 and caspase-3,leading to elevations of their activities (P ＜ 0.05).Conclusion Emodin inhibites cell proliferation of human bile duct carcinoma cell QBC939 through inducing apoptosis.The mechanism is associated with the elevated levels of reactive oxygen species and the activation of caspase-9 cells and caspase-3. Key words: Emodin;  Apoptosis;  Reactive oxygen species;  Caspases