Antimicrobial and Antiplasmid Activities of Essential Oils

Fitoterapia. 2006 Jun;77(4):279-85. doi: 10.1016/j.fitote.2006.03.013. Epub 2006 May 11.


The antimicrobial and antiplasmid activities of essential oils (orange oil, eucalyptus oil, fennel oil, geranium oil, juniper oil, peppermint oil, rosemary oil, purified turpentine oil, thyme oil, Australian tea tree oil) and of menthol, the main component of peppermint oil, were investigated. The antimicrobial activities were determined on the Gram (+) Staphylococcus epidermidis and the Gram (-) Escherichia coli F'lac K12 LE140, and on two yeast Saccharomyces cerevisiae 0425 delta/1 and 0425 52C strains. The antiplasmid activities were investigated on E. coli F'lac bacterial strain. Each of the oils exhibited antimicrobial activity and three of them antiplasmid action. The interaction of peppermint oil and menthol with the antibiotics was studied on the same bacterial strain with the checkerboard method. Peppermint oil and menthol displayed additive synergy with oxytetracycline. A new mechanism of plasmid curing was established for one of the oil components.

MeSH terms

  • Anti-Bacterial Agents / administration & dosage
  • Anti-Bacterial Agents / pharmacology*
  • Anti-Bacterial Agents / therapeutic use
  • Antifungal Agents / administration & dosage
  • Antifungal Agents / pharmacology
  • Antifungal Agents / therapeutic use
  • Drug Synergism
  • Escherichia coli / classification
  • Escherichia coli / drug effects*
  • Humans
  • Microbial Sensitivity Tests
  • Phytotherapy*
  • Plant Oils / administration & dosage
  • Plant Oils / pharmacology*
  • Plant Oils / therapeutic use
  • Plants, Medicinal*
  • Saccharomyces cerevisiae / classification
  • Saccharomyces cerevisiae / drug effects
  • Staphylococcus epidermidis / drug effects*


  • Anti-Bacterial Agents
  • Antifungal Agents
  • Plant Oils