Total saponins of Tupistra chinensis induces apoptosis in A549 cells.

Tupistra chinensis Baker has been used as a folk remedy in China, and it has been shown to exhibit anti-inflammation, expectorant and anti-bacterial effects. In this study, we report the cytotoxic activity of the total saponins of Tupistra chinensis Baker (TST) against several carcinoma cell lines, including A549, MCF-7 and HeLa cells with the IC50 values of 4.11 μg/ml, 6.47 μg/ml and 7.78 μg/ml respectively. Treatment of A549 cells with TST resulted in growth inhibition and induction of apoptosis in a time-dependent manners determined by cell viability, chromatin condensation, DNA fragmentation and flow cytometry analysis. The activities of caspase-3, 9 were significantly increased following TST treatment. Real-time PCR analysis showed that the mRNA expression levels of pro-apoptosis related genes including Bax, P21, P27 and P53 were markedly increased in the cells treated with TST but anti-apoptosis related gene Bcl-2 was slightly decreased. TST also leads to a loss of mitochondrial membrane potential in a time-dependent manner the release of cytochrome C from mitochondria into the cytosol. Thus, these results suggest that TST may play an important role in tumor growth suppression by inducing apoptosis in human A549 cells via mitochondria-dependent apoptotic pathways and the TST would be promising to treat human lung adenocarcinoma.