title: Antimicrobial Activity and Modulatory Effect of Essential Oil from the Leaf of Rhaphiodon echinus (Nees &amp; Mart) Schauer on Some Antimicrobial Drugs.
abstract: BACKGROUND
  Rhaphiodon echinus is a weed plant used in the Brazilian folk medicinal for the treatment of infectious diseases. In this study, the essential oil of R. echinus leaf was investigated for its antimicrobial properties.
  
  
  METHODS
  The chemical constituents of the essential oil were characterized by GC-MS. The antimicrobial properties were determined by studying by the microdilution method the effect of the oil alone, and in combination with antifungal or antibiotic drugs against the fungi Candida albicans, Candida krusei and Candida tropicalis and the microbes Escherichia coli, Staphylococcus aureus and Pseudomonas. In addition, the iron (II) chelation potential of the oil was determined.
  
  
  RESULTS
  The results showed the presence of β-caryophyllene and bicyclogermacrene in major compounds, and revealed a low antifungal and antibacterial activity of the essential oil, but a strong modulatory effect on antimicrobial drugs when associated with the oil. The essential oil showed iron (II) chelation activity.
  
  
  CONCLUSIONS
  The GC-MS characterization revealed the presence of monoterpenes and sesquiterpenes in the essential oil and metal chelation potential, which may be responsible in part for the modulatory effect of the oil. These findings suggest that essential oil of R. echinus is a natural product capable of enhancing the antibacterial and antifungal activity of antimicrobial drugs.
authors.affiliation: Centro de Ci&#234;ncias Biol&#243;gicas e da Sa&#250;de (CC BS), Departamento de Ci&#234;ncias Biol&#243;gicas, Universidade Regional do Cariri (URCA), Crato 63105-000, CE, Brazil. duarte105@yahoo.com.br.|Programa de P&#243;s-Gradua&#231;&#227;o em Bioqu&#237;mica Toxicol&#243;gica, Departamento de Bioqu&#237;mica e Biologia Molecular, Universidade Federal de Santa Maria, Santa Maria 97105-900, RS, Brazil. duarte105@yahoo.com.br.
authors.forename: Antonia Eliene
authors.initials: AE
authors.lastname: Duarte
authors.affiliation: Molecular Chemistry and Pharmacology Laboratory, Universidade Regional do Cariri (URCA), Crato 63105-000, CE, Brazil. irwin.alencar@urca.br.
authors.forename: Irwin Rose Alencar
authors.initials: IR
authors.lastname: de Menezes
authors.affiliation: Centro de Ci&#234;ncias Biol&#243;gicas e da Sa&#250;de (CC BS), Departamento de Ci&#234;ncias Biol&#243;gicas, Universidade Regional do Cariri (URCA), Crato 63105-000, CE, Brazil. flavianamoraisb@yahoo.com.br.
authors.forename: Maria Flaviana
authors.initials: MF
authors.lastname: Bezerra Morais Braga
authors.affiliation: Centro de Ci&#234;ncias Biol&#243;gicas e da Sa&#250;de (CC BS), Departamento de Ci&#234;ncias Biol&#243;gicas, Universidade Regional do Cariri (URCA), Crato 63105-000, CE, Brazil. nadghia.fl@gmail.com.
authors.forename: Nadghia Figueiredo
authors.initials: NF
authors.lastname: Leite
authors.affiliation: Centro de Ci&#234;ncias Biol&#243;gicas e da Sa&#250;de (CC BS), Departamento de Ci&#234;ncias Biol&#243;gicas, Universidade Regional do Cariri (URCA), Crato 63105-000, CE, Brazil. lmarivando@hotmail.com.|Programa de P&#243;s-Gradua&#231;&#227;o em Bioqu&#237;mica Toxicol&#243;gica, Departamento de Bioqu&#237;mica e Biologia Molecular, Universidade Federal de Santa Maria, Santa Maria 97105-900, RS, Brazil. lmarivando@hotmail.com.
authors.forename: Luiz Marivando
authors.initials: LM
authors.lastname: Barros
authors.affiliation: Programa de P&#243;s-Gradua&#231;&#227;o em Bioqu&#237;mica Toxicol&#243;gica, Departamento de Bioqu&#237;mica e Biologia Molecular, Universidade Federal de Santa Maria, Santa Maria 97105-900, RS, Brazil. memypw@yahoo.com.br.
authors.forename: Emily Pansera
authors.initials: EP
authors.lastname: Waczuk
authors.affiliation: Centro de Ci&#234;ncias Biol&#243;gicas e da Sa&#250;de (CC BS), Departamento de Ci&#234;ncias Biol&#243;gicas, Universidade Regional do Cariri (URCA), Crato 63105-000, CE, Brazil. arlene.pessoa@urca.br.|Laborat&#243;rio de Bot&#226;nica Aplicada, Universidade Regional do Cariri (URCA), Crato 63105-000, CE, Brazil. arlene.pessoa@urca.br.
authors.forename: Maria Arlene
authors.initials: MA
authors.lastname: Pessoa da Silva
authors.affiliation: Programa de P&#243;s-Gradua&#231;&#227;o em Bioqu&#237;mica Toxicol&#243;gica, Departamento de Bioqu&#237;mica e Biologia Molecular, Universidade Federal de Santa Maria, Santa Maria 97105-900, RS, Brazil. alineboligon@hotmail.com.
authors.forename: Aline
authors.initials: A
authors.lastname: Boligon
authors.affiliation: Programa de P&#243;s-Gradua&#231;&#227;o em Bioqu&#237;mica Toxicol&#243;gica, Departamento de Bioqu&#237;mica e Biologia Molecular, Universidade Federal de Santa Maria, Santa Maria 97105-900, RS, Brazil. jbtrocha@yahoo.com.br.
authors.forename: João Batista
authors.initials: JB
authors.lastname: Teixeira Rocha
authors.affiliation: Departamento de Bioqu&#237;mica, Instituto de Ci&#234;ncias B&#225;sica da Sa&#250;de, Universidade Federal do Rio Grande do Sul, Porto Alegre 90035-191, RS, Brazil. diogo@ufrgs.br.
authors.forename: Diogo Onofre
authors.initials: DO
authors.lastname: Souza
authors.affiliation: Programa de P&#243;s-Gradua&#231;&#227;o em Bioqu&#237;mica Toxicol&#243;gica, Departamento de Bioqu&#237;mica e Biologia Molecular, Universidade Federal de Santa Maria, Santa Maria 97105-900, RS, Brazil. kamdemjeanpaul2005@yahoo.fr.|Departamento de Bioqu&#237;mica, Instituto de Ci&#234;ncias B&#225;sica da Sa&#250;de, Universidade Federal do Rio Grande do Sul, Porto Alegre 90035-191, RS, Brazil. kamdemjeanpaul2005@yahoo.fr.
authors.forename: Jean Paul
authors.initials: JP
authors.lastname: Kamdem
authors.affiliation: Laboratory of Microbiology and Molecular Biology, Universidade Regional do Cariri (URCA), Crato 63105-000, CE, Brazil. hdmcoutinho@gmail.com.
authors.forename: Henrique Douglas
authors.initials: HD
authors.lastname: Melo Coutinho
authors.affiliation: Programa de P&#243;s-Gradua&#231;&#227;o em Bioqu&#237;mica Toxicol&#243;gica, Departamento de Bioqu&#237;mica e Biologia Molecular, Universidade Federal de Santa Maria, Santa Maria 97105-900, RS, Brazil. mariliseeb@yahoo.com.br.|Programa de P&#243;s-Gradua&#231;&#227;o em Farmacologia, Universidade Federal de Santa Maria, Santa Maria 97105-900, RS, Brazil. mariliseeb@yahoo.com.br.
authors.forename: Marilise
authors.initials: M
authors.lastname: Escobar Burger
mesh_terms: D000890:Anti-Infective Agents / Q000737:chemistry / Q000494:pharmacology*; D000935:Antifungal Agents / Q000737:chemistry / Q000494:pharmacology*; D001938:Brazil; D002176:Candida albicans / Q000187:drug effects / Q000472:pathogenicity; D004926:Escherichia coli / Q000187:drug effects / Q000472:pathogenicity; D006801:Humans; D007239:Infections / Q000188:drug therapy* / Q000382:microbiology; D019686:Lamiaceae / Q000737:chemistry*; D039821:Monoterpenes / Q000737:chemistry; D009822:Oils, Volatile / Q000737:chemistry / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry; D010938:Plant Oils / Q000737:chemistry / Q000494:pharmacology*; D012717:Sesquiterpenes / Q000737:chemistry; D013211:Staphylococcus aureus / Q000187:drug effects / Q000472:pathogenicity
chemical_list: D000890:Anti-Infective Agents; D000935:Antifungal Agents; D039821:Monoterpenes; D009822:Oils, Volatile; D010938:Plant Oils; D012717:Sesquiterpenes
keywords: R. echinus; antibacterial activity; antifungal activity; modulating; natural products