Antitumor Activity of Aralia racemosa

The southern Appalachians are home to an extraordinary variety of plant species, many of which have been used medicinally by local populations. The vast majority of these species have not been studied for their antitumor activity, constituting a significant bioexploration opportunity. We have recently begun a targeted screening program for identifying plants indigenous to Western North Carolina with potential antitumor activity. Initial screening against the MCF-7 breast tumor cell line identified an extract of Aralia racemosa (aerial parts) as having cytotoxic activity. Combined CH₂Cl₂ extractions of the acidified crude organic extract showed dose-dependent toxicity towards MCF-7 cells, with IC₅₀ around 100 µg/mL. Bioassay-guided fractionation by reverse phase C₁₈ open column chromatography, followed by reverse phase C₁₈ HPLC, afforded the major cytotoxic component, a twenty-carbon terpenoid, along with an inactive twenty-carbon compound. The major cytotoxic compound gives 73% inhibition growth of MCF-7 cells at 100 µg/mL. The structure has been characterized by NMR spectroscopy and ESI-MS, and these results will be presented. Acknowledgements: We thank the Western Carolina University SURF Program for summer support for T.J.W. We thank Wake Forest University Health Sciences Virus and Vector Core Laboratory for assay work.