Activity of plant flavonoids against antibiotic-resistant bacteria.
Thirty eight plant-derived flavonoids representing seven different structural groups were tested for activities against antibiotic-resistant bacteria using the disc-diffusion assay and broth dilution assay. Among the flavonoids examined, four flavonols (myricetin, datiscetin, kaempferol and quercetin) and two -flavones (flavone and luteolin) exhibited inhibitory activity against methicillin-resistant Staphylococcus aureus (MRSA). Myricetin was also found to inhibit the growth of multidrug-resistant Burkholderia -cepacia, vancomycin-resistant enterococci (VRE) and other medically important organisms such as -Klebsiella pneumoniae and Staphylococcus epidermidis. Myricetin was bactericidal to B. cepacia. The results of the radiolabel incorporation assay showed that myricetin inhibited protein synthesis by -B. cepacia. The structure-activity relationship of these flavonoids is discussed.
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Department of Applied Oral Science, Faculty of Dentistry, Dalhousie University, Halifax, Nova Scotia, Canada B3H 3J5.
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D019117:Burkholderia / Q000187:drug effects; D016983:Enterococcus / Q000187:drug effects; D005419:Flavonoids / Q000494:pharmacology*; D044948:Flavonols; D006090:Gram-Negative Bacteria / Q000187:drug effects*; D006094:Gram-Positive Bacteria / Q000187:drug effects*; D006801:Humans; D007711:Klebsiella pneumoniae / Q000187:drug effects; D016106:Methicillin Resistance; D008826:Microbial Sensitivity Tests; D010946:Plants, Medicinal; D013211:Staphylococcus aureus / Q000187:drug effects; D013329:Structure-Activity Relationship; D020713:Vancomycin Resistance
D005419:Flavonoids; D044948:Flavonols