title: Menadione (vitamin K) enhances the antibiotic activity of drugs by cell membrane permeabilization mechanism.
abstract: Menadione, vitamin K3, belongs to the class of lipid-soluble vitamins and lipophilic substances as menadione cause disturbances in the bacterial membrane, resulting in damage to the fundamental elements for the integrity of the membrane, thus allowing increased permeability. Accordingly, the aim of this study was to evaluate in vitro the antibiotic-modifying activity of menadione in multiresistant strains ofStaphylococcus aureus,Pseudomonas aeruginosaandEscherichia coli, with a gradual increase in its subinhibitory concentration. In addition, menadione was compared with cholesterol and ergosterol for similarity in mechanism of drug modulatory action. Antibiotic-modifying activity and antibacterial effect were determined by the broth microdilution assay. Menadione, cholesterol and ergosterol showed modulatory activity at clinically relevant concentrations, characterizing them as modifiers of bacterial drug resistance, since they lowered the MIC of the antibiotics tested. This is the first report of the antibacterial activity of menadione and its potentiation of aminoglycosides against multiresistant bacteria.
authors.affiliation: Universidade Regional do Cariri, Crato (CE), Brazil.
authors.forename: Jacqueline C
authors.initials: JC
authors.lastname: Andrade
authors.affiliation: Universidade Regional do Cariri, Crato (CE), Brazil.
authors.forename: Maria Flaviana B
authors.initials: MF
authors.lastname: Morais Braga
authors.affiliation: Universidade Regional do Cariri, Crato (CE), Brazil.
authors.forename: Gláucia Morgana M
authors.initials: GM
authors.lastname: Guedes
authors.affiliation: Universidade Regional do Cariri, Crato (CE), Brazil.
authors.forename: Saulo R
authors.initials: SR
authors.lastname: Tintino
authors.affiliation: Universidade Regional do Cariri, Crato (CE), Brazil.
authors.forename: Maria A
authors.initials: MA
authors.lastname: Freitas
authors.affiliation: Universidade Federal de Sergipe, Aracaju (SE), Brazil.
authors.forename: Lucindo J
authors.initials: LJ
authors.lastname: Quintans
authors.affiliation: Universidade Regional do Cariri, Crato (CE), Brazil.
authors.forename: Irwin R A
authors.initials: IR
authors.lastname: Menezes
authors.affiliation: Universidade Regional do Cariri, Crato (CE), Brazil.
authors.forename: Henrique D M
authors.initials: HD
authors.lastname: Coutinho
keywords: Antibiotic-modifying; Lipid solubility; Menadione; Microdilution; Permeabilization