ABSTRACT
OBJECTIVE:To study the inhibitory effect and mechanism of Inula helenium ethyl acetate extract(IHE)on prolif-eration of human pancreatic cancer Capan-2 cells. METHODS:MTT was used to determine the cell proliferation inhibition rate af-ter treated by 0,0.5,1,2,4,8 μg/mL IHE;clone formation test was used to observe the effects of 0,1,2 μg/mL IHE treating for 1 week on cell clone formation;Hoechest 33342 staining was used to observe the changes of nuclear morphology after treated by 0,2,4 μg/mL IHE for 48 h;flow cytometry was used to detect the cell apoptosis rate after treated by 0,4,8,16 μg/mL IHE for 48 h;JC-1 staining was used to observe the changes of intracellular mitochondrial membrane potential after treated by 0,4,8, 16 μg/mL IHE for 24 h;Western blot was used to detect the expressions of mitochondrial apoptosis-related proteins Bcl-2,Bax, Mcl-1,p53 up-regulated modulator of apoptosis (PUMA),and polymerase (PARP) after treated by 0,4,8,16 μg/mL IHE for 48 h. RESULTS:2,4,8 μg/mL IHE had obvious inhibitory effect on cell proliferation,showing concentration-dependent relation-ship,with IC50 of 6.6 μg/mL;1,2 μg/mL IHE can obviously inhibit the clone formation of cells;4 μg/mL IHE can obviously cause cell nuclear condensation;8,16 μg/mL IHE can obviously promote the cell apoptosis,and the cell apoptosis rate reached 45.53% after treated by 16 μg/mL IHE for 48 h;16 μg/mL IHE treating for 24 h can cause the decrease of 82.47% cells'mito-chondrial membrane potential;8 μg/mL IHE can obviously down-regulate the protein expressions of Bcl-2,Mcl-1,PUMA and PARP,and 16 μg/mL IHE can obviously down-regulate the expressions of Mcl-1 and PUMA. CONCLUSIONS:IHE may show its inhibitory effect on proliferation of human pancreatic cancer Capan-2 cells by causing the decrease of mitochondrial mem-brane potential in cells and down-regulating the protein expres-sions of Mcl-1 and PUMA to cause cell apoptosis.