Effect of Licochalcone A on Apoptosis in Human Breast Cancer MDA-MB-231 Cells / 中国实验方剂学杂志

ABSTRACT

Objective:To investigate the effect of licochalcone A （LCA） on apoptosis in human breast cancer MDA-MB-231 cells， and to explore its possible mechanism. Method:MDA-MB-231 cells were treated with LCA of different concentrations， and<italic> </italic>cell counting kit-8 （CCK-8） assay was used to detect the cell viability. The cells were treated with LCA （10， 20， and 40 μmol·L^-1） for 24 h， and apoptosis was detected by Annexin V staining with fluorescein isothiocyanate （FITC） and propidium iodide （PI） （Annexin V-FITC/PI）. The level of intracellular reactive oxygen species （ROS） was detected by 2′，7′-dichlorodihydrofluorescein diacetate （DCFA-DA） fluorescent probe. Mitochondrial membrane potential （MMP） was detected by 5， 5′， 6， 6′-tetrachloro-1， 1′， 3， 3′-tetraethyl-imidacarbocyanine （JC-1） fluorescence probe. Western blot was used to detect the expression of cell apoptosis-related proteins， such as B-cell lymphoma-2 （Bcl-2） and Bcl-2-associated X protein （Bax）， and endoplasmic reticulum （ER） stress-related proteins， such as C/EBP homologous protein （CHOP）， activating transcription factor 4 （ATF4）， protein kinase R-like ER kinase （PERK）， p-PERK， eukaryotic translation initiation factor 2 alpha （eIF2<italic>α</italic>）， and p-eIF2<italic>α</italic>. Result:With the increase in the drug concentration （starting from 5 μmol·L^-1）， the cell viability decreased （<italic>P<</italic>0.05） with IC₅₀of 19.05 μmol·L^-1 as compared with the normal group. Additionally， the apoptosis rates of the LCA groups （10， 20， 40 μmol·L^-1） significantly increased （<italic>P</italic><0.05）， which reached 30.2% （<italic>P</italic><0.05） at LCA concentration of 40 μmol·L^-1. LCA （10， 20， and 40 μmol·L^-1） decreased the expression of Bcl-2 （<italic>P<</italic>0.05） and increased Bax expression （<italic>P<</italic>0.05） in a dose-dependent manner. Besides， the intracellular ROS level was elevated （<italic>P<</italic>0.05） and mitochondrial MMP was reduced （<italic>P<</italic>0.05） after LCA （10， 20， and 40 μmol·L^-1） treatment in a dose-dependent manner， leading to mitochondrial dysfunction. LCA （10， 20， and 40 μmol·L^-1） induced ER stress to up-regulate the expression of CHOP， ATF4， p-PERK， and p-eIF2<italic>α</italic> （<italic>P<</italic>0.05） in a dose-dependent manner. Conclusion:LCA can induce MDA-MB-231 cell apoptosis by increasing intracellular ROS level and reducing MMP to trigger mitochondrial dysfunction and ER stress.