Comparison of the cidal activity of tea tree oil and terpinen-4-ol against clinical bacterial skin isolates and human fibroblast cells

Lett Appl Microbiol. 2008 Apr;46(4):428-33. doi: 10.1111/j.1472-765X.2008.02334.x. Epub 2008 Feb 22.


Aims: The aim of this study was to compare both the antimicrobial activity of terpinen-4-ol and tea tree oil (TTO) against clinical skin isolates of meticillin-resistant Staphylococcus aureus (MRSA) and coagulase-negative staphylococci (CoNS) and their toxicity against human fibroblast cells.

Methods and results: Antimicrobial activity was compared by using broth microdilution and quantitative in vitro time-kill test methods. Terpinen-4-ol exhibited significantly greater bacteriostatic and bactericidal activity, as measured by minimum inhibitory and bactericidal concentrations, respectively, than TTO against both MRSA and CoNS isolates. Although not statistically significant, time-kill studies also clearly showed that terpinen-4-ol exhibited greater antimicrobial activity than TTO. Comparison of the toxicity of terpinen-4-ol and TTO against human fibroblasts revealed that neither agent, at the concentrations tested, were toxic over the 24-h test period.

Conclusions: Terpinen-4-ol is a more potent antibacterial agent against MRSA and CoNS isolates than TTO with neither agent exhibiting toxicity to fibroblast cells at the concentrations tested.

Significance and impact of the study: Terpinen-4-ol should be considered for inclusion as a single agent in products formulated for topical treatment of MRSA infection. However, further work would initially be required to ensure that resistance would not develop with the use of terpinen-4-ol as a single agent.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anti-Bacterial Agents / pharmacology*
  • Anti-Bacterial Agents / toxicity
  • Cell Line
  • Fibroblasts / drug effects*
  • Humans
  • Methicillin Resistance
  • Mice
  • Microbial Sensitivity Tests
  • Microbial Viability / drug effects*
  • Skin / microbiology
  • Staphylococcus / drug effects*
  • Staphylococcus / isolation & purification
  • Tea Tree Oil / pharmacology*
  • Tea Tree Oil / toxicity
  • Terpenes / pharmacology*
  • Terpenes / toxicity


  • Anti-Bacterial Agents
  • Terpenes
  • terpinenol-4
  • Tea Tree Oil