Anticancer Activity of an Oplopanax elatus Stem Extract and Biologically Active Isolated Compounds

Background and Methods: Oplopanax elatus (Nakai) Nakai is used in folk medicine in China. In this study, the antiproliferative activity of an O. elatus fraction extracted by ethyl acetate (EF) was tested on human breast cancer MCF-7 cells, human colon cancer HCT-116 cells, and human stomach cancer AGS cells. The potential mechanism of antiproliferation was also investigated using an apoptosis assay. Results: The results showed that the EF remarkably suppressed proliferation of human breast, stomach, and colon cancer cells. Further apoptosis tests by flow cytometry and immunoblot analyses showed the EF inhibited HCT-116 cell proliferation by inducing apoptosis. The bioassay-monitored fractionation of the EF resulted in the isolation of two polyacetylenes, falcarindiol (compound 1) and oplopandiol (compound 2), with falcarindiol possessing the strongest antiproliferative activity in colon cancer cells. Conclusion: Together, this study evaluated the anticancer activity of an O. elatus extract against human cancer cells, and provided the basis for further development of this herbal extract for the treatment of cancer.