Pseudolaric acid B induces apoptosis in MG-63 human osteosarcoma cells through Bcl-2 degradation and caspase-dependent pathway

Pseudolaric acid B (PAB) is the primary bioactive compound isolated from traditional Chinese herb Tu-Jin-Pi, and exerts anti-tumor effects in various types of human cancer cells. However, so far, there has been no any study concerning the effect of PAB on human osteosarcoma (OS) cells. In the present study, we for the first time reported the anti-tumor effects of PAB on MG-63 OS cells. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) assay and clone formation assay showed that PAB significantly inhibited MG-63 cell proliferation in a dose- and time-dependent manner. The typical morphology changes and results of Annexin V-FITC/PI staining indicated that PAB induced apoptosis occurred in MG-63 cells. Furthermore, we also proved that PAB had the ability to suppress the migration and invasion of MG-63 cells. The western blotting data suggested that PAB induced apoptosis may be attributable to the increased Bax and Bcl-2 degradation through caspase-3 dependent singaling pathways. In conclusion, these findings revealed that PAB possessed significant antitumor effects on MG-63 cells and might serve as a novel therapeutic agent for the treatment of human OS.