title: Enhancement of the antibiotic activity of aminoglycosides by alpha-tocopherol and other cholesterol derivates.
abstract: Alpha-tocopherol, one of the most abundant isoforms of vitamin E, is a biologically active liposoluble vitamin and potent antioxidant. It occurs naturally in foods of plant and animal origin. Because of its lipophilic character, it can cause perturbations in the bacterial cell membrane, resulting in damage to components essential for the integrity of the membrane, thereby allowing an increase in permeability. This is the first report of the modulatory effect of alpha-tocopherol in multiresistant bacteria. We evaluated alpha-tocopherol against multiresistant strains of Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli, and determined if there was any similarity with the mechanism of modulatory action of cholesterol and ergosterol. When combined with aminoglycosides in a microdilution broth assay, alpha-tocopherol possibly acted through a lipophilic action on the cell envelope, modulating more effectively P. aeruginosa and E. coli, when compared with S. aureus.
authors.affiliation: Departamento de Química Biológica, Universidade Regional do Cariri - URCA, Crato-CE, Rua Cel. Antonio Luis 1161, Pimenta, 63105-000, Brazil.
authors.forename: Jacqueline C
authors.initials: JC
authors.lastname: Andrade
authors.affiliation: Departamento de Química Biológica, Universidade Regional do Cariri - URCA, Crato-CE, Rua Cel. Antonio Luis 1161, Pimenta, 63105-000, Brazil.
authors.forename: Maria Flaviana B
authors.initials: MF
authors.lastname: Morais-Braga
authors.affiliation: Departamento de Química Biológica, Universidade Regional do Cariri - URCA, Crato-CE, Rua Cel. Antonio Luis 1161, Pimenta, 63105-000, Brazil.
authors.forename: Glaucia M M
authors.initials: GM
authors.lastname: Guedes
authors.affiliation: Departamento de Química Biológica, Universidade Regional do Cariri - URCA, Crato-CE, Rua Cel. Antonio Luis 1161, Pimenta, 63105-000, Brazil.
authors.forename: Saulo R
authors.initials: SR
authors.lastname: Tintino
authors.affiliation: Departamento de Química Biológica, Universidade Regional do Cariri - URCA, Crato-CE, Rua Cel. Antonio Luis 1161, Pimenta, 63105-000, Brazil.
authors.forename: Maria A
authors.initials: MA
authors.lastname: Freitas
authors.affiliation: Departamento de Química Biológica, Universidade Regional do Cariri - URCA, Crato-CE, Rua Cel. Antonio Luis 1161, Pimenta, 63105-000, Brazil.
authors.forename: Irwin R A
authors.initials: IR
authors.lastname: Menezes
authors.affiliation: Departamento de Química Biológica, Universidade Regional do Cariri - URCA, Crato-CE, Rua Cel. Antonio Luis 1161, Pimenta, 63105-000, Brazil. Electronic address: hdmcoutinho@gmail.com.
authors.forename: Henrique D M
authors.initials: HD
authors.lastname: Coutinho
mesh_terms: D000617:Aminoglycosides / Q000008:administration & dosage* / Q000737:chemistry; D000900:Anti-Bacterial Agents / Q000008:administration & dosage* / Q000737:chemistry; D002784:Cholesterol / Q000008:administration & dosage* / Q000737:chemistry; D004338:Drug Combinations; D004357:Drug Synergism; D004926:Escherichia coli / Q000187:drug effects / Q000502:physiology; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000379:methods; D013211:Staphylococcus aureus / Q000187:drug effects / Q000502:physiology; D024502:alpha-Tocopherol / Q000008:administration & dosage* / Q000737:chemistry
chemical_list: D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D004338:Drug Combinations; D002784:Cholesterol; D024502:alpha-Tocopherol
keywords: Alpha-tocopherol; Aminoglycosides; Bacterial resistance; Liposoluble vitamin; Modulation; Permeabilization