Antimicrobial activity of a traditionally used complex essential oil distillate (Olbas(®) Tropfen) in comparison to its individual essential oil ingredients

Phytomedicine. 2012 Aug 15;19(11):969-76. doi: 10.1016/j.phymed.2012.05.014. Epub 2012 Jun 26.


Plant extracts and essential oils have been widely studied and used as antimicrobial agents in the last decades. In our study we investigated the antimicrobial activities of Olbas(®) Tropfen (in the following named Olbas), a traditionally used complex essential oil distillate, in comparison to its individual essential oil ingredients. Olbas (10 g) consists of three major components such as peppermint oil (5.3 g), eucalyptus oil (2.1 g), and cajuput oil (2.1 g) and of two minor constituents like juniper berry oil (0.3 g) and wintergreen oil (0.2 g). The composition of Olbas and the five individual essential oils were characterized by GLC-MS. According to GLC-MS analysis 1,8-cineol is the main component of the complex essential oil distillate followed by menthol and menthone. The minimum inhibitory and minimum microbicidal concentrations of Olbas and each of the single essential oils were evaluated in 17 species/strains of bacteria and fungi. Time-kill assay was performed to compare the microbicidal activity of Olbas and peppermint oil during several time intervals. Olbas displayed a high antimicrobial activity against all test strains used in this study, among them antibiotic resistant MRSA (methicillin-resistant Staphylococcus aureus) and VRE (vancomycin-resistant Enterococcus). Its antimicrobial activity was comparable to that of peppermint oil which was the most potent one of all individual essential oils tested. In the time kill assay Olbas as well as peppermint oil demonstrated similar microbicidal activities. Based on its wide antimicrobial properties Olbas can be a useful agent for the treatment of uncomplicated infections of skin and respiratory tract.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Infective Agents / chemistry
  • Anti-Infective Agents / pharmacology*
  • Candida / drug effects*
  • Cyclohexanols / chemistry
  • Cyclohexanols / pharmacology
  • Dose-Response Relationship, Drug
  • Eucalyptol
  • Gram-Negative Bacteria / drug effects*
  • Gram-Positive Bacteria / drug effects*
  • Mentha piperita
  • Methicillin Resistance
  • Microbial Sensitivity Tests
  • Monoterpenes / chemistry
  • Monoterpenes / pharmacology
  • Oils, Volatile / chemistry
  • Oils, Volatile / pharmacology*
  • Plant Extracts
  • Plant Oils / chemistry
  • Plant Oils / pharmacology
  • Salicylates
  • Terpenes / chemistry
  • Terpenes / pharmacology
  • Time Factors
  • Vancomycin Resistance


  • Anti-Infective Agents
  • Cyclohexanols
  • Monoterpenes
  • Oils, Volatile
  • Plant Extracts
  • Plant Oils
  • Salicylates
  • Terpenes
  • wintergreen oil
  • peppermint oil
  • cajuput oil
  • Eucalyptol
  • juniper berry oil