title: Efficacy of Plectranthus amboinicus (Lour.) Spreng in a Murine Model of Methicillin-Resistant Staphylococcus aureus Skin Abscesses.
abstract: The present work aimed to evaluate the effectiveness of Plectranthus amboinicus (Lour.) Spreng against MRSA clinical isolates. The in vitro antimicrobial activity of the hydroalcoholic extract (HE), the ethyl acetate (EA) fraction and its subfractions were determined by broth microdilution and bioautography against MRSA clinical isolates. The microdilution checkerboard method was used to assess in vitro drug combination studies. To induce abscess formation, bacterial suspensions were added to Citodex and inoculated subcutaneously into male Swiss mice. The treatment protocol consisted of 2 doses of HE, the EA fraction or vancomycin introduced intraperitoneally into mice 3 and 12 h after infection. The EA fraction and its subfractions presented the lowest minimal inhibitory concentrations (MIC, 0.25 to 0.5 mg/mL). The plant samples were bacteriostatic at 2x and 4x MIC and bactericidal at 100 mg/mL. The EA fraction presented synergism with vancomycin and an additive effect with ciprofloxacin. A significant reduction of abscess volume, bacterial cell counts in abscess slurries, and inflammatory scores was observed in the HE and EA fraction-treated groups. The samples were effective in treating the animals in a dose-dependent fashion. The present study proved the effectiveness of P. amboinicus fractions against MRSA using in vitro and in vivo assays.
authors.affiliation: Department of Clinical Analysis and Toxicology, Faculty of Pharmacy, Universidade Federal do Ceará (UFC), Rua Capitão Francisco Pedro 1210, 60430-370 Fortaleza, CE, Brazil.
authors.forename: Francisco Fábio Martins
authors.initials: FF
authors.lastname: de Oliveira
authors.forename: Alba Fabiola
authors.initials: AF
authors.lastname: Torres
authors.forename: Thially Braga
authors.initials: TB
authors.lastname: Gonçalves
authors.forename: Gilvandete Maria Pinheiro
authors.initials: GM
authors.lastname: Santiago
authors.forename: Cibele Barreto Mano
authors.initials: CB
authors.lastname: de Carvalho
authors.forename: Milena Braga
authors.initials: MB
authors.lastname: Aguiar
authors.forename: Lilia Maria Carneiro
authors.initials: LM
authors.lastname: Camara
authors.forename: Silvia Helena
authors.initials: SH
authors.lastname: Rabenhorst
authors.forename: Alice Maria Costa
authors.initials: AM
authors.lastname: Martins
authors.forename: José Telmo
authors.initials: JT
authors.lastname: Valença Junior
authors.forename: Aparecida Tiemi
authors.initials: AT
authors.lastname: Nagao-Dias