title: In vitro activity of Brazilian medicinal plants, naturally occurring naphthoquinones and their analogues, against methicillin-resistant Staphylococcus aureus.
abstract: Fourteen extracts from Brazilian traditional medicinal plants used to treat infectious diseases were used to look for potential antimicrobial activity against multiresistant bacteria of medical importance. Staphylococcus aureus strains were susceptible to extracts of Punica granatum and Tabebuia avellanedae. The minimum inhibitory concentrations (MICs) of the total extracts and of additional fractions of these plants were determined by employing strains of methicillin-resistant (MRSA) and -sensitive (MSSA) S. aureus, including isolates of the PFGE clone A, which is prevalent in Brazil and two ATCC reference strains. A mixture of ellagitannins isolated from P. granatum and two naphthoquinones isolated from T. avellanedae demonstrated antibacterial activity against all S. aureus strains tested. Semi-synthetic furanonaphthoquinones (FNQs) showed lower MICs than those exhibited by natural occurring naphthoquinones. The results indicate that these natural products can be effective potential candidates for the development of new strategies to treat MRSA infections.
authors.affiliation: Núleo de Pesquisas de Productos Naturais, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: T B
authors.initials: TB
authors.lastname: Machado
authors.forename: A V
authors.initials: AV
authors.lastname: Pinto
authors.forename: M C F R
authors.initials: MC
authors.lastname: Pinto
authors.forename: I C R
authors.initials: IC
authors.lastname: Leal
authors.forename: M G
authors.initials: MG
authors.lastname: Silva
authors.forename: A C F
authors.initials: AC
authors.lastname: Amaral
authors.forename: R M
authors.initials: RM
authors.lastname: Kuster
authors.forename: K R
authors.initials: KR
authors.lastname: Netto-dosSantos
mesh_terms: D001938:Brazil; D006801:Humans; D047348:Hydrolyzable Tannins; D066298:In Vitro Techniques; D029561:Lythraceae; D016106:Methicillin Resistance; D008826:Microbial Sensitivity Tests; D009285:Naphthoquinones / Q000008:administration & dosage / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D008517:Phytotherapy; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology; D010946:Plants, Medicinal; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000382:microbiology; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000302:isolation & purification; D029663:Tabebuia; D013634:Tannins / Q000008:administration & dosage / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology
chemical_list: D047348:Hydrolyzable Tannins; D009285:Naphthoquinones; D010936:Plant Extracts; D013634:Tannins; C013515:ellagitannin