Effect of Stemona tuberosa Alkaloids on Apoptosis and PI3K/Akt and JNK/MAPK Signaling Pathways of Human Lung Cancer A549 Cells / 中国实验方剂学杂志

ABSTRACT

ObjectiveTo investigate the effect of Stemona tuberosa alkaloids （STA） on apoptosis and phosphatidylinositol 3-kinase/protein kinase B （PI3K/Akt） and c-Jun N-terminal kinase/p38 mitogen-activated protein kinase （JNK/p38 MAPK） signaling pathways in human lung cancer A549 cells. MethodA549 cells were classified into blank group and STA groups （100， 150， 200， 250， 300 mg⋅L-1）. Thiazole blue （MTT） assay and colony formation assay were used to evaluate the proliferation of A549 cells. Apoptosis was observed based on Hoechst 33258 staining， flow cytometry， and Annexin V-FITC/PI staining. Western blot was employed to detect the expression of apoptosis-related proteins cysteine-aspartic acid protease-3 （Caspase-3）， B-cell lymphoma-2 （Bcl-2）-associated X protein （Bax）， and Bcl-2， and the expression of PI3K， phosphorylated （p）-PI3K， Akt， p-Akt， JNK， p-JNK， p38 MAPK， and p-p38 MAPK. ResultCompared with the blank group， STA groups （150， 200， 250， 300 mg⋅L-1） demonstrated the increase in inhibition rate of cell proliferation （P<0.01） and cell clone inhibition rate， and decrease in cell clone formation rate （P<0.01）. In comparison with the blank group， STA groups showed typical characteristics of apoptosis， such as chromatin condensation and enhanced fluorescence reaction. The apoptosis rate of STA groups was significantly higher than that of the blank group （P<0.01）. Compared with the blank group， STA （150， 200， 250， 300 mg⋅L-1） significantly up-regulated the protein expression of Caspase-3 and Bax （P<0.05， P<0.01） and down-regulated the expression of Bcl-2 protein （P<0.01）. Compared with the blank group， STA had no significant influence on the total protein expression of PI3K， Akt， JNK， and p38 MAPK. However， STA （150， 200， 250， 300 mg⋅L-1） significantly decreased the levels of p-PI3K and p-Akt （P<0.05， P<0.01） and increased the level of p-p38 MAPK （P<0.05， P<0.01）. Compared with the blank group， STA （200， 250， 300 mg⋅L-1） significantly raised the level of p-JNK （P<0.05， P<0.01）. ConclusionSTA can inhibit the proliferation and induce the apoptosis of A549 cells by inhibiting PI3K/Akt signaling pathway and activating JNK/p38 MAPK signaling pathway.