ABSTRACT
<p><b>OBJECTIVE</b>To observe in vitro and in vivo effects of triptolide on growth inhibition and apoptosis of osteosarcoma cells, and to further explore its correlated molecular mechanisms.</p><p><b>METHODS</b>The growth inhibition effects of triptolide on osteosarcoma cells were detected using MTT assay. The apoptosis was detected using flow cytometry.The protein expressions of associated signals were detected using Western blot. The in vivo anti-osteosarcoma effects of triptolide were verified in osteosarcoma nude mice. The in vivo associated protein expressions were detected using immunohistochemistry (IHC).</p><p><b>RESULTS</b>Triptolide could significantly inhibit the proliferation of various osteosarcoma cells. Besides, it could induce their apoptosis. Triptolide triggered the mitochondrial dependent apoptotic pathway, significantly inhibited the in vivo growth of osteosarcoma cells, and caused in vivo apoptosis.</p><p><b>CONCLUSIONS</b>Triptolide induced apoptosis of osteosarcoma cells partially through activating mitochondria associated apoptosis signal pathway. Triptolide also induced apoptosis of osteosarcoma cells and inhibited their in vivo growth in nude mice.</p>