Platycodin D, a triterpenoid saponin from Platycodon grandiflorum, suppresses the growth and invasion of human oral squamous cell carcinoma cells via the NF-κB pathway

This work was undertaken to explore the effects of platycodin D, a triterpenoid saponin from Platycodon grandiflorum, on the growth and invasiveness of human oral squamous cell carcinoma (OSCC). Platycodin D caused a significant, concentration-dependent inhibition of cell viability and induced significant apoptosis in OSCC cells. Moreover, platycodin D significantly inhibited OSCC cell invasion. At the molecular level, platycodin D increased the amounts of IB protein and reduced the expression of phosphorylated NF-B p65, MMP-2, and MMP-9. Ectopic expression of constitutively active NF-B p65 prevented platycodin D-mediated induction of apoptosis and suppression of invasion in OSCC cells. In vivo studies confirmed that platycodin D retarded the growth of subcutaneous SCC-4 xenograft tumors and reduced phosphorylation of NF-B p65. Altogether, platycodin D shows inhibitory activity on OSCC growth and invasion through inactivation of the NF-B pathway and might provide therapeutic benefits in the treatment of OSCC.