Methods: The effect of the extract of Inula helenium on growth of KB oral cancer cell and the mechanism were investigated using MTT assay, western blot assay and caspase activity assay.
Results: Treatment of the extract of Inula helenium in KB cells induced the apoptotic cell death in a concentration- and a time-dependent manner. Furthermore, The extract of Inula helenium induced the DNA fragmentation of KB cells. In western blot analysis, the proteolytic processing of caspase-3, -7 and -9 was increased by the extract of Inula helenium treatment in KB cells. In addition, activation of caspase-3 and caspase-7 was detected in living KB cells by fluorescence microscopy.
Conclusions: These results suggest that the extract of Inula helenium can induce the suppression of cell growth and cell apoptosis in KB oral cancer cells, and therefore, that it may have potential properties for anti-tumor drug discovery.