title: Antibacterial and synergistic effects of the n-BuOH fraction of Sophora flavescens root against oral bacteria.
abstract: The antibacterial activity of an extract and several fractions of Sophora flavescens (S. flavescens) root alone and in combination with antibiotics against oral bacteria was investigated by checkerboard assay and time-kill assay. The minimum inhibitory concentration/minimum bactericidal concentration (MIC/MBC) values for all examined bacteria were 0.313-2.5/0.625-2.5 μg/mL for the n-BuOH fraction, 0.625-5/1.25-10 μg/mL for the EtOAc fraction, 0.25-8/0.25-16 μg/mL for ampicillin, 0.5-256/1-512 μg/mL for gentamicin, 0.008-32/0.016-64 μg/mL for erythromycin, and 0.25-64/0.5-128 μg/mL for vancomycin. The n-butanol (n-BuOH) and ethyl acetate (EtOAc) fractions exhibited stronger antibacterial activity against oral bacteria than other fractions and extracts. The MICs and MBCs were reduced to between one half and one quarter when the n-BuOH and EtOAc fractions were combined with antibiotics. After 24 h of incubation, combination of 1/2 MIC of the n-BuOH fraction with antibiotics increased the degree of bactericidal activity. The present results suggest that n-BuOH and EtOAc extracts of S. flavescens root might be applicable as new natural antimicrobial agents against oral pathogens.
authors.affiliation: Department of Oral Microbiology, School of Dentistry, Chonbuk National University.
authors.forename: Kyung-Yeol
authors.initials: KY
authors.lastname: Lee
authors.forename: Su-Mi
authors.initials: SM
authors.lastname: Cha
authors.forename: Sung-Mi
authors.initials: SM
authors.lastname: Choi
authors.forename: Jeong-Dan
authors.initials: JD
authors.lastname: Cha
mesh_terms: D020001:1-Butanol / Q000737:chemistry*; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects*; D004357:Drug Synergism; D006801:Humans; D008826:Microbial Sensitivity Tests; D009055:Mouth / Q000382:microbiology*; D010936:Plant Extracts / Q000494:pharmacology*; D018517:Plant Roots / Q000737:chemistry*; D029909:Sophora / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D010936:Plant Extracts; D020001:1-Butanol