| 2156 Oral Antimicrobial Compounds from Hydrastis canadensis L. (Goldenseal) Leaves | ||
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J. COULBURN1, Y.-W. CHIN2, H. PAREKH1, S. YILDIZ1, R. BEAVERS3, A.D. KINGHORN2, and C.D. WU1, 1University of Illinois at Chicago, USA, 2Ohio State University, Columbus, USA, 3Sleepy Hollow Farm, Dalton, GA, USA We have previously identified antimicrobial alkaloids, such as berberine, active against selected oral pathogens from root/rhizome of Hydrastis canadensis L. (Goldenseal), a popular phytomedicine sold in the United States. In a subsequent effort to explore the antimicrobial components from the aerial parts of the plant, the crude methanol extract also demonstrated growth inhibitory activity. Objective: This study represents a continued effort in the isolation and identification of compounds from the aerial parts of H.canadensis and the analysis of their antimicrobial activity. Methods: Ground leaves/stems were extracted with 100% methanol and partitioned with hexanes, CHCl3, EtOAc, and an aqueous portion. The active CHCl3-soluble partition was subjected to silica-gel column chromatography, pure compounds were isolated using HPLC and chemical structures identified by NMR spectroscopy. Antimicrobial activity, the Minimum Inhibitory Concentration (MIC) of fractions/compounds was evaluated, alone and in combination with berberine, against Streptococcus mutans (Sm) and Fusobacterium nucleatum (Fn). Viability and attachment of Fn and Porphyromonas gingivalis (Pg) to a berberine-coated glass surface (100µg/ml) was also evaluated by image analysis. Results: Antimicrobial assay-guided fractionation of the active CHCl3-soluble partition identified subfractions with growth inhibitory activity against Sm and Fn (MICs:62.5µg/ml to 500µg/ml). When combined with berberine, additive effects were noted (Fractional Inhibitory Concentration:0.56 to 1.0). Two flavonoids novel to H.canadensis, 8-demethylsideroxylin and sideroxylin, and an alkaloid (-)-8-oxotetrahydrothalifendine were purified and identified from the CHCl3-subfractions. When a glass surface was pretreated with the antimicrobial alkaloid, berberine, a 24% reduction in attachment of Fn was observed with live/dead ratio of 1:3 compared with the non-treated control (4:1). Similar treatment did not affect attachment of Pg. Conclusion: In addition to the root/rhizome, aerial parts of H.canadensis also serve as a source of natural antimicrobial phytochemicals including flavonoids and alkaloids that may suppress growth and virulence properties of oral pathogens. (Supported by USDA Grant #2004-33610-14721) | ||
| Seq #226 - Nutrition Posters 3:30 PM-4:45 PM, Friday, March 23, 2007 Ernest N. Morial Convention Center Exhibit Hall I2-J | ||
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