Effects of proanthocyanidins on apoptosis in human lung cancer cell line A549

Objective To investigate the effects of proanthocyanidins on apoptosis of human lung cancer cell line A549,and to explore the anticancer mechanism. Methods A549 cells were cultured with different concentrations of PA.The proliferation rate of cell was measured by MTT.Cell apoptosis was observed with Hoechst 33258/propidium iodide(PI) staining assay by fluorescence microscope.DNA ladder was observed through agarose gel electrophoresis,and the caspase-9,caspase-3 and Bcl-2 protein expressions were detected by Western blot. Results PA inhibited the growth of A549 cells with a dose-and time-dependent manner.When A549 cells were exposed for 48 hours with 25 mg/L,cells showed typical characteristic changes of apoptosis by fluorescence staining.Typical DNA ladder was observed in apoptosis.Western blot results showed the expression of apoptosis related proteins caspase-9 and caspase-3 increased significantly following drug concerntration,but the expression of Bcl-2 decreased. Conclusions PA can inhibit the proliferation of A549 cells through inducing cell apoptosis,and the mechanism may be related to mitochondrial apoptosis pathway.