Ethnopharmacological relevance-Devil's Club Oplopanax horridus (Sm.) Miq. is a widely used folk medicine in the Pacific Northwest such as Alaska and British Columbia for treating a variety of ailments including arthritis, cold, fever, infections, diabetes and cancer.Aim of the study-To investigate hydrophobic constituents and their potential anticancer activity from Devil's Club O. horridus.
Materials and methods-The root bark of O. horridus (Sm.) Miq was isolated by chromatographic techniques. Structures of isolated compounds were identified by spectroscopic methods and comparison with published data. The anti-proliferation of isolated hydrophobic constituents in human breast cancer MCF-7 cells, human colon cancer SW-480 and HCT-116 cells were tested. The potential mechanism of anti-proliferation was also investigated using cell cycle and apoptosis assays.Results and discussion-Six compounds were isolated and structurally identified as 9,17-octadecadiene-12,14-diyne-1,11,16-triol, 1-acetate (1), oplopandiol acetate (2), falcarindiol (3), oplopandiol (4), trans-nerolidol (5) and t-cadinol (6). These compounds showed potential anticancer activities on human breast cancer and colon cancer cells, of which compound 3 possesses the strongest activity. Further cell cycle and apoptosis test by flow cytometry showed the polyacetylenes 1-4 induced HCT-116 cell arresting in G2/M phase and inhibited proliferation by the induction of apoptosis at both earlier and later stage.Conclusion-These results provide promising baseline information for the potential use of O. horridus as well as some of the isolated compounds in the treatment of cancer.