Antibacterial activity of sophoraflavanone G isolated from the roots of Sophora flavescens.
This study investigated the antibacterial activities of sophoraflavanone G from Sophora flavescens in combination with two antimicrobial agents against oral bacteria. The combined effect of sophoraflavanone G and the antimicrobial agents was evaluated using the checkerboard method to obtain a fractional inhibitory concentration (FIC) index. The sophoraflavanone G+ampicillin (AM) combination was found to have a synergistic effect against S. mutans, S. sanguinis, S. sobrinus, S. gordonii, A. actinomycetemcomitans, F. nucleatum, P. intermedia, and P. gingivalis, whereas the sophoraflavanone G+gentamicin (GM) combination had a synergistic effect against S. sanguinis, S. criceti, S. anginosus, A. actinomycetemcomitans, F. nucleatum, P. intermedia, and P. gingivalis. Neither combination exhibited any antagonistic interactions (FIC index >4). In particular, the MICs/MBCs for all the bacteria were reduced to one-half - one-sixteenth as a result of the drug combinations. A synergistic interaction was also confirmed by time-kill studies for nine bacteria where the checkerboard suggested synergy. Thus, a strong bactericidal effect was exerted through the drug combinations, plus in vitro data suggested that sophoraflavanone G combined with other antibiotics may be microbiologically beneficial rather than antagonistic.
Institute of Oral Bioscience and Department of Oral Microbiology School of Dentistry, Chonbuk National University, Jeonju 361-763, Korea.
Jeong-Dan
JD
Cha
Mi-Ran
MR
Jeong
Seung-Il
SI
Jeong
Kyung-Yeol
KY
Lee
D000667:Ampicillin / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000302:isolation & purification* / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects*; D015169:Colony Count, Microbial; D004357:Drug Synergism; D044950:Flavanones / Q000302:isolation & purification* / Q000494:pharmacology; D005839:Gentamicins / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability; D018517:Plant Roots / Q000737:chemistry*; D029909:Sophora / Q000737:chemistry*
D000900:Anti-Bacterial Agents; D044950:Flavanones; D005839:Gentamicins; D000667:Ampicillin; C064849:vexibinol