Dendrobium nobile is widely used as an
analgesic, an
antipyretic, and a tonic to nourish the stomach in
traditional medicine. Mounting evidence suggests an antitumor activity of
denbinobin, a major
phenanthrene isolated from stems of Dendrobium nobile. The present study aimed to investigate the inhibitory effect of
denbinobin on the invasive ability of human
cancer cells. The cytotoxicity of denbonobin was examined in several human
cancer cell lines including SK-Hep-1 hepato-
carcinoma cells, SNU-484
gastric cancer cells, and HeLa
cervix cancer cells. Because SNU-484 cells showed the lowest IC50 value, we examined the effect of
denbinobin on the invasive ability of SNU-484 cells. The present study revealed, for the first time, that
denbinobin inhibits the invasive phenotype of SNU-484 human
gastric cancer cells in a dose-dependent manner. Expressions of
matrix metalloproteinase (MMP)-2 and MMP-9 were significantly decreased by
denbinobin, suggesting that
MMP-2/-9 may be responsible for the anti-invasive activity of
denbinobin. We also provide evidence that
denbinobin induces apoptosis through down-regulation of Bcl-2 and an up-regulation of Bax. Taken together, this study demonstrates that
denbinobin inhibits invasion and induces apoptosis in highly invasive SNU-484 human
gastric cancer cells. Given that
gastric cancer has been estimated to be one of the most common causes of
cancer-related death among Asians and the major cause of death from
gastric cancer is the metastatic spread of the disease, our findings may provide useful information regarding the application of
denbinobin as a chemopreventive agent that could prevent or alleviate metastatic
gastric cancer.