Radix Tetrastigma Hemsleyani Flavone Induces Apoptosis in Human Lung Carcinoma A549 Cells by Modulating the MAPK Pathway

Radix Tetrastigma Hemsleyani Flavone (RTHF) is widely used as a traditional herb for its detoxificationand anti-inflammation activity. Recently, several studies have shown that RTHF can inhibit growth and induceapoptosis in human cancer cell lines. However, the mechanisms are not completely understood yet. In this studywe investigated the potential effects of RTHF on growth and apoptosis in human lung adenocarcinoma A549 cellsas well as its mechanisms. A549 cells were treated with RTHF at various concentrations for different times. Invitro the MTT assay showed that RTHF had obvious anti-proliferation effects on A549 cells in a dose- and timedependentmanner. Cell morphological changes observed by inverted microscope and Hoechst33258 methodswere compared with apoptotic changes observed by fluorescence microscope. Cell apoptosis inspected by flowcytometry showed significant increase in the treatment group over the control group (P<0.01). Expression ofapoptosis related Bax/Bcl-2, caspases and MAPK pathway proteins were detected by Western blotting. Theresults showed that RTHF up-regulated the Bax/Bcl-2 ratio and cle-caspase3/9, cle-PARP expression in a dosedependentmanner. Expression of p-p38 increased, p-ERK decreased significantly and that of p-JNK was littlechanged in the RTHF group when compared with the control group. These results suggest that RTHF mightexert anti-growth and apoptosis activity against lung cancer A549 cells through activation of caspases and Bcl-2family proteins and the MAPK pathway, therefore presenting as a promising therapeutic agent for the treatmentof lung cancer.