Total Saponins of Aralia elata （Miq.） Seem Leaves （TSAESL） Inhibits Tumor Cell Proliferation and Induces Apoptosis via activating MAPK signaling pathways in MCF-7 human breast cancer cells

Aim Aralia elata （Miq.） Seem is a medicinal plant with a variety of biological activities. Several trier- pene saponins extracted from the leaves of Aralia elata （Miq.） Seem possess potent cytotoxic activity, but the mechanisms remain unclear. Methods In the present study, we examined the anti-tumor activity of total saponins of Aralia elata （Miq.） Seem leaves （TSAESL） using both in vitro and in vivo experiments, and investigated the underlying molecular mechanisms. Results Briefly, TSAESL significantly inhibited the proliferation of five human cancer cell lines and induced apoptosis of MCF-7 cells in a concentration-dependent manner. TSAESL also in- creased the expression level of active caspase-3 and cleaved PARP. In addition, TSAESL dramatically activated the phosphorylation of ERK1/2, p38 and JNK in a concentration-dependent manner. Treatment with the ERK1/2 in- hibitor U0126, p38 inhibitor SB203580, or JNK inhibitor SP600125 prior to TSAESL exposure markedly attenuated TSAESL-induced phosphorylation of ERK1/2 and p38. In mice bearing MCF-7 xenografl, TSAESL markedly inhib- ited tumor growth without significantly affecting spleen coefficient and hematological parameters. Conclusion These results strongly suggest that TSAESL has anti-tumor effect via activating the MAPK-mediated signaling path- ways.