Induction of apoptosis on human lung cancer A549 cell line via casticin and its mechanisms

Objective To investigate the apoptosis induced by casticin on human lung cancer A549 cells and the mechanism involved.Methods Human lung cancer A549 cell line was cultured in vitro.The inhibitory effect of casticin on the proliferation of human lung cancer A549 cells was measured by MTT assay.Casticin-induced apoptosis rates of A549 cells were observed by flow cytometry with annexin V/PI fluorescence staining.The cell mitochondrial membrane potential was detected by flow cytometry with the probe of JC-1.Cytochromes-c release of mitochondrion and Bax protein expression were analyzed by Western blotting assay.Results The MTT assay showed that casticin had significantly inhibitory effect on the cell proliferation of A549 cells in a concentration-dependent manner.The flow cytometry with annexin V/PI fluorescence staining indicated that the apoptosis rates of A549 cells treated with 10μmol/L casticin for 12,24 and 48h were 22.39%,38.66% and 64.82% respectively.The flow cytometry with the probe of JC-1 indicated that casticin could down-regulate mitochondrial membrane potential of A549 cells.The results of Western blotting assay demonstrated that the cytochromes-c release of mitochondrion increased,and the expression of Bax up-regulated.Conclusion Casticin possesses a significant function to inhibite the proliferation of A549 cells and to induce the apoptosis of A549 cells,which may be due to the association with down-regulating mitochondrial membrane potential and increasing cytochromes-c release and up-regulating the expression of Bax protein.