RESUMEN
OBJECTIVE To study the effects of the active component 17-hydroxy-jolkinolide B （HJB） of Euphorbia fischeriana on the proliferation and apoptosis of human triple-negative breast cancers （TNBC） MDA-MB-231 and MDA-MB-468 cells. METHODS MTT assay was adopted to detect the inhibitory rate of MDA-MB-231 and MDA-MB-468 cells proliferation after treated with 0 （blank control），5，10，20，40，80 μmol/L HJB for 24， 48 and 72 h. Laser confocal microscope and flow cytometry were adopted to detect the apoptosis， mitochondrial membrane potential（MMP） and reactive oxygen species （ROS） of above 2 kinds of cells after treated with 0 （blank control）， 10，20，40 μmol/L HJB for 24 h. Western blot assay was used to detect the expressions of B cell lymphoma-2（ Bcl-2）， Bcl-2-associated X protein （Bax）， cytochrome-C （Cyt-C）， caspase-3， cleaved caspase- 3， caspase-9 and cleaved caspase-9. RESULTS Compared with blank control group， 5，10，20，40，80 μmol/L HJB could significantly increase the inhibitory rate of MDA-MB-231 and MDA-MB-468 cells proliferation （P＜0.05）， in dose- and time- dependent trend. After 24 h treatment of HJB （10，20，40 μmol/L）， the apoptosis of above 2 kinds of cells increased， and the total apoptotic rate increased significantly （P＜0.05）； the mitochondrial membrane potential decreased significantly （P＜0.05）； the level of ROS increased significantly （P＜0.05）； the protein expressions of Bcl-2， caspase-3 and caspase-9 were decreased significantly （P＜ 0.05）， while the protein expressions of Cyt-C， Bax， cleaved caspase-3 and cleaved caspase-9 were increased significantly （P＜0.05）. CONCLUSIONS HJB can inhibit the proliferation of MDA-MB-231 and MDA-MB-468 cells， and induce their apoptosis.