Abstract
Artemisia douglasiana, also known as California mugwort or Douglas' sagewort, is used commonly among Native California tribes for treating colds and infections as well as premenstrual syndrome and dysmenorrhea. Previous work in this laboratory had shown that California mugwort is cytotoxic towards the cultured breast cancer cell lines MDA-MB-23 1 and BT-474. The purpose of this study was to isolate the chemical constituents responsible for this cytoxicity. A. douglasiana leaves were collected and prepared as ethanol extract. The EC50 values for the ethanol-soluble and hexane-soluble fractions were 1.8 1tg/ml and 0.053 jtg/ml for MDA-MB-23 1, respectively, and 1.2 [Ig/ml and 0.025 jig/ml for BT-474, respectively. Various schemes were investigated to separate the chemical components of the leaf extracts, including liquid-liquid extraction, thin layer chromatography (TLC), flash column chromatography, and adsorption onto lead tetraacetate. Cytotoxicity assays on MDA-MB-23 1 were used to guide the isolation. High-performance liquid chromatography - charged aerosol detection, gas chromatography - mass spectrometry, TLC, and nuclear magnetic resonance were used to assess the purity of fractions. A method was developed to isolate a single cytotoxic compound from the plant leaf extract, but the amount obtained was too small to characterize and identify by chemical means or bioassay.