Potentiating effect of Mentha arvensis and chlorpromazine in the resistance to aminoglycosides of methicillin-resistant Staphylococcus aureus

In Vivo. Mar-Apr 2009;23(2):287-9.


Background: This is the first report testing the antibiotic resistance-modifying activity of Mentha arvensis against MRSA (methicillin-resistant Staphylococcus aureus).

Materials and methods: In this study an ethanol extract of Mentha arvensis L. and chlorpromazine were tested for their antimicrobial activity alone or in combination with conventional antibiotics against MRSA strains.

Results: A potentiating effect of this extract on gentamicin, kanamycin and neomycin was demonstrated. Similarly, a potentiating effect of chlorpromazine on the same aminoglycosides was observed, indicating the involvement of an efflux system in the resistance to these antibiotics.

Conclusion: It is therefore suggested that extracts from M. arvensis could be used as a source of plant-derived natural products with resistance-modifying activity, such as in the case of aminoglycosides, constituting a new weapon against bacterial resistance to antibiotics, as with chlorpromazine.

MeSH terms

  • Aminoglycosides / metabolism*
  • Anti-Bacterial Agents / pharmacology
  • Chlorpromazine / analysis
  • Chlorpromazine / pharmacology*
  • Dopamine Antagonists / analysis
  • Dopamine Antagonists / pharmacology*
  • Drug Evaluation, Preclinical
  • Drug Resistance, Microbial
  • Drug Synergism
  • Ethanol / chemistry
  • Mentha / metabolism*
  • Methicillin-Resistant Staphylococcus aureus / metabolism*
  • Plant Extracts / pharmacology*
  • Plant Leaves / metabolism
  • Staphylococcal Infections / drug therapy


  • Aminoglycosides
  • Anti-Bacterial Agents
  • Dopamine Antagonists
  • Plant Extracts
  • Ethanol
  • Chlorpromazine