title: Antibacterial action against food-borne microorganisms and antioxidant activity of carvacrol-rich oil from Lippia origanoides Kunth.
abstract: BACKGROUND
  Lippia origanoides Kunth from Northeast Brazil is a plant of pleasant odor used by local people as a food seasoning in substitution the oregano where its carvacrol-rich oil has showed significant antimicrobial activity against human pathogens.
  
  
  METHODS
  GC and GC-MS analyzed the plant oil composition and its antibacterial activity was evaluated by disk diffusion and microdilution broth methods. The determination of oil antioxidant activity was made by DPPH radical scavenging assay. Oil toxicity was performed on mice.
  
  
  RESULTS
  The main constituents of the oil were carvacrol (47.2%), thymol (12.8%), p-cymene (9.7%), and p-methoxythymol (7.4%). The oil was active against the bacteria of Bacillus cereus, B. subtilis, and Salmonella typhimurium, except for Pseudomonas aeruginosa. The antioxidant activity has displayed a high dose-response (r(2) = 0.92), with the inhibition of DPPH radical from 15 to 82%, at concentrations from 5 to 50 μg/mL, and also by the β-carotene bleaching assay, which showed a high inhibition of 85.2 ± 6.8 %, corresponding to about 80% of the inhibition of Trolox (93.4 ± 0.7%), used as a standard. The lethal dose (LD50) of the oil was determined in 1673.84 mg mL(-1).
  
  
  CONCLUSIONS
  The results confirmed that the oil of L. origanoides could be utilized for the prevention of food bacterial growth, and as an antioxidative agent for retardation of food oxidation process. The oil has low toxicity, allowing its application in the food industry. Graphical Abstract Aerial parts of Lippia origanoides Kunth.
authors.affiliation: Programa de Pós-Graduação em Biodiversidade e Biotecnologia da Amazônia Legal, Universidade Federal do Amazonas, Manaus, 60077-000, , AM, Brazil. sarrazin@ufpa.br.
authors.forename: Sandra Layse F
authors.initials: SL
authors.lastname: Sarrazin
authors.affiliation: Programa de Pós-Graduação em Recursos Naturais da Amazônia, Universidade Federal do Oeste do Pará, Santarém, 68135-110, , PA, Brazil. andrade.biologia@hotmail.com.
authors.forename: Leomara A
authors.initials: LA
authors.lastname: da Silva
authors.affiliation: Programa de Pós-Graduação em Recursos Naturais da Amazônia, Universidade Federal do Oeste do Pará, Santarém, 68135-110, , PA, Brazil. rbo@ufpa.br.
authors.forename: Ricardo B
authors.initials: RB
authors.lastname: Oliveira
authors.affiliation: Programa de Pós-Graduação em Química, Universidade Federal do Pará, Belém, 66075-110, , PA, Brazil. juraposo_qui@yahoo.com.br.
authors.forename: Juliana Divina A
authors.initials: JD
authors.lastname: Raposo
authors.affiliation: Programa de Pós-Graduação em Química, Universidade Federal do Pará, Belém, 66075-110, , PA, Brazil. joycekellys@ufpa.br.
authors.forename: Joyce Kelly R
authors.initials: JK
authors.lastname: da Silva
authors.affiliation: Departamento de Botânica, Instituto de Ciências Biológicas, Universidade Federal de Juiz de Fora, Juiz de Fora, 36036-330, , MG, Brazil. fatima.salimena@ufjf.edu.br.
authors.forename: Fátima Regina G
authors.initials: FR
authors.lastname: Salimena
authors.affiliation: Programa de Pós-Graduação em Recursos Naturais da Amazônia, Universidade Federal do Oeste do Pará, Santarém, 68135-110, , PA, Brazil. gmaia@ufpa.br.|Programa de Pós-Graduação em Química, Universidade Federal do Pará, Belém, 66075-110, , PA, Brazil. gmaia@ufpa.br.
authors.forename: José Guilherme S
authors.initials: JG
authors.lastname: Maia
authors.affiliation: Programa de Pós-Graduação em Biodiversidade e Biotecnologia da Amazônia Legal, Universidade Federal do Amazonas, Manaus, 60077-000, , AM, Brazil. mouraorhv@yahoo.com.br.|Programa de Pós-Graduação em Recursos Naturais da Amazônia, Universidade Federal do Oeste do Pará, Santarém, 68135-110, , PA, Brazil. mouraorhv@yahoo.com.br.
authors.forename: Rosa Helena V
authors.initials: RH
authors.lastname: Mourão
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D001409:Bacillus cereus / Q000187:drug effects; D001412:Bacillus subtilis / Q000187:drug effects; D001713:Biphenyl Compounds / Q000737:chemistry; D052978:Disk Diffusion Antimicrobial Tests; D016166:Free Radical Scavengers / Q000737:chemistry / Q000494:pharmacology*; D007928:Lethal Dose 50; D032411:Lippia / Q000737:chemistry*; D008297:Male; D051379:Mice; D010851:Picrates / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D010938:Plant Oils / Q000737:chemistry / Q000494:pharmacology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D012486:Salmonella typhimurium / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D010851:Picrates; D010936:Plant Extracts; D010938:Plant Oils; C004931:1,1-diphenyl-2-picrylhydrazyl