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

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.

Mechanism of Stemona tuberosa Alkaloids in Inhibiting Proliferation and Inducing Apoptosis of Non-small Cell Lung Cancer NCI-H460 Cells / 中国实验方剂学杂志

ObjectiveTo study the effect and underlying mechanism of Stemona tuberosa alkaloids on the proliferation and apoptosis of human non-small cell lung cancer NCI-H460 cells. MethodNon-small cell lung cancer NCI-H460 cells were divided into a blank group and S. tuberosa alkaloids groups （50， 100， 150， 200， and 250 mg·L-1）. The effect of S. tuberosa alkaloids on the proliferation of human NCI-H460 cells was observed by thiazolyl blue tetrazolium bromide （MTT） assay and colony formation assay. Cell apoptosis was observed by Hoechst 33258 staining and flow cytometry. Real-time fluorescence-based polymerase chain reaction （Real-time PCR） was used to detect the effect of S. tuberosa alkaloids on the mRNA expression of cysteinyl aspartate-specific protease 3 （Caspase-3）， B-cell lymphoma-2 （Bcl-2）， Bcl-2-associated X protein （Bax）， and epidermal growth factor receptor （EGFR）. The protein expression levels of Caspase-3， Bax， Bcl-2， protein kinase B （Akt）， phosphorylated （p-）Akt， EGFR， c-Jun N-terminal kinase （JNK）， p-JNK， p38 mitogen-activated protein kinase （p38 MAPK）， and p-p38 MAPK were measured by Western blot. ResultCompared with the blank group， the S. tuberosa alkaloids groups showed increased inhibition rate on cell proliferation （P<0.01）， reduced number of cell clones formed and the rate of cell clonal formation （P<0.05， P<0.01）， and increased karyopyknosis， cytoplasmic aggregation， and cell apoptosis rate （P<0.01）. The S. tuberosa alkaloids groups at 100， 150， 200， and 250 mg·L-1 showed increased Caspase-3 mRNA expression （P<0.05）， decreased EGFR mRNA expression （P<0.05， P<0.01）， up-regulated protein expression of Caspase-3 and p-JNK （P<0.01）， and down-regulated protein expression of EGFR and p-Akt （P<0.05， P<0.01）. Additionally， compared with the blank group， the S. tuberosa alkaloids groups showed increased expression of Bax mRNA （P<0.01）， decreased expression of Bcl-2 mRNA （P<0.01）， up-regulated protein expression of Bax and p-p38 MAPK （P<0.01）， and down-regulated protein expression of Bcl-2 （P<0.01）. ConclusionsS. tuberosa alkaloids can inhibit proliferation and induce apoptosis of human non-small cell lung cancer NCI-H460 cells， and the mechanism may be related to the inhibition of EGFR protein expression and phosphorylation of Akt protein， as well as the activation of the JNK/p38 MAPK signaling pathway.

Effect of Stemona tuberosa Alkaloids on Apoptosis of SMMC-7721 Cells and Expression of Bcl-2， Bax， and Cleaved Caspase-3 / 中国实验方剂学杂志

Objective:To investigate the effect of<italic> Stemona tuberosa</italic> alkaloids on the apoptosis of human hepatoma SMMC-7721 cells and the expression of apoptosis-related proteins including B lymphocytoma-2 （Bcl-2）， Bcl-2-associated X protein （Bax）， and cleaved cysteinyl aspartate-specific protease-3 （cleaved Caspase-3）. Method:SMMC-7721 cells were routinely cultured， passaged， and treated with various concentrations （50， 75， 112， 167， and 250 mg·L^-1） of <italic>S. tuberosa </italic>alkaloids， while those in the blank control group were only treated with 10% fetal bovine serum. The cell proliferation was determined by tetrazolium bromide （MTT） colorimetry and colony assay and the cell apoptosis by Hoechst 33258 staining. The protein expression levels of Bcl-2， Bax， and cleaved Caspase-3 were detected by Western blot. Result:<italic>S. tuberosa</italic> alkaloids inhibited the proliferation of SMMC-7721 cells， and the inhibition rate was significantly increased in comparison with that in the blank control group （<italic>P</italic><0.01）， with the half maximal inhibitory concentrations （IC₅₀） at 24 h， 48 h， and 72 h being （173.36±8.75）， （112.14±16.50）， and （96.41±2.60）mg·L^-1， respectively. The cell colony-inhibitory activity was significantly increased in a dose-dependent manner （<italic>P</italic><0.01）. Compared with the blank control group， <italic>S. tuberosa</italic> alkaloids promoted the apoptosis of SMMC-7721 cells， manifested as increased number of apoptotic cells and elevated apoptotic rate （<italic>P</italic><0.01）. The typical morphological changes such as brightly blue-fluorescent condensed nuclei， cytoplasmic shrinking， and karyopyknosis were found under the upright fluorescence microscope. As revealed by comparison with the blank control group， the expression of Bcl-2 was significantly down-regulated （<italic>P</italic><0.01）， while the protein expression levels of pro-apoptotic protein Bax and cleaved Caspase-3 in the 75， 112， 167， and 250 mg·L^-1 <italic>S. tuberosa</italic> alkaloids groups were significantly up-regulated （<italic>P</italic><0.01）. Conclusion:<italic>S. tuberosa </italic>alkaloids inhibit the proliferation of SMMC-7721 cells and promote their apoptosis possibly by inhibiting Bcl-2 protein expression and promoting Bax and cleaved Caspase-3 protein expression.