title: The antibacterial and antifungal activity of essential oils extracted from Guatemalan medicinal plants.
abstract: BACKGROUND
  Essential oils are prevalent in many medicinal plants used for oral hygiene and treatment of diseases.
  
  
  OBJECTIVE
  Medicinal plant species were extracted to determine the essential oil content. Those producing sufficient oil were screened for activity against Staphylococcus aureus, Escherichia coli, Streptococcus mutans, Lactobacillus acidophilus, and Candida albicans.
  
  
  METHODS
  Plant samples were collected, frozen, and essential oils were extracted by steam distillation. Minimum inhibitory concentrations (MIC) were determined using a tube dilution assay for those species yielding sufficient oil.
  
  
  RESULTS
  Fifty-nine of the 141 plant species produced sufficient oil for collection and 12 species not previously reported to produce essential oils were identified. Essential oil extracts from 32 species exhibited activity against one or more microbes. Oils from eight species were highly inhibitory to S. mutans, four species were highly inhibitory to C. albicans, and 19 species yielded MIC values less than the reference drugs.
  
  
  CONCLUSIONS
  RESULTS suggest that 11 species were highly inhibitory to the microbes tested and merit further investigation. Oils from Cinnamomum zeylanicum Blume (Lauraceae), Citrus aurantiifolia (Christm.) Swingle (Rutaceae), Lippia graveolens Kunth (Verbenaceae), and Origanum vulgare L. (Lamiaceae) yielded highly significant or moderate activity against all microbes and have potential as antimicrobial agents.
  
  
  CONCLUSIONS
  Teas prepared by decoction or infusion are known methods for extracting essential oils. Oils from 11 species were highly active against the microbes tested and merit investigation as to their potential for addressing health-related issues and in oral hygiene.
authors.affiliation: Department of Biology, College of Life Sciences, Brigham Young University (BYU) , Provo, UT , USA .
authors.forename: Andrew B
authors.initials: AB
authors.lastname: Miller
authors.forename: Rex G
authors.initials: RG
authors.lastname: Cates
authors.forename: Michael
authors.initials: M
authors.lastname: Lawrence
authors.forename: J Alfonso Fuentes
authors.initials: JA
authors.lastname: Soria
authors.forename: Luis V
authors.initials: LV
authors.lastname: Espinoza
authors.forename: Jose Vicente
authors.initials: JV
authors.lastname: Martinez
authors.forename: Dany A
authors.initials: DA
authors.lastname: Arbizú
mesh_terms: D000900:Anti-Bacterial Agents / Q000302:isolation & purification / Q000494:pharmacology*; D000935:Antifungal Agents / Q000302:isolation & purification / Q000494:pharmacology*; D002176:Candida albicans / Q000187:drug effects / Q000254:growth & development; D006090:Gram-Negative Bacteria / Q000187:drug effects / Q000254:growth & development; D006094:Gram-Positive Bacteria / Q000187:drug effects / Q000254:growth & development; D006166:Guatemala; D008826:Microbial Sensitivity Tests; D009822:Oils, Volatile / Q000302:isolation & purification / Q000494:pharmacology*; D010946:Plants, Medicinal / Q000737:chemistry* / Q000254:growth & development; D013045:Species Specificity
chemical_list: D000900:Anti-Bacterial Agents; D000935:Antifungal Agents; D009822:Oils, Volatile
keywords: Antimicrobial activity; Guatemala; MIC; aromatic plants