Mohaddese Mahboubi and Nastaran Kazempour

pp. 83 - 87

Abstract

Peppermint with antiseptic and known healing properties is a plant from the Labiatae family. In this study, we analyzed
the chemical composition of essential oil from the flowering aerial part of peppermint by GC and GC/MS. Its antimicrobial
activity was evaluated against bacteria, fungi and yeast by micro broth dilution assay. The fractional inhibitory concentration
(FIC) and FIC Index (FICI) and related isobologram curve were determined by check board micro titer assay. The results
exhibited that the MIC, MLC value of peppermint oil against different kinds of microorganisms were in the range of 0.125-2
and 0.125- >64 µl/ml, respectively. Candida albicans was the most sensitive microorganism and Pseudomonas aeruginosa
was the less sensitive ones. The oil showed synergistic activities with vancomycin, gentamycin, and amphotericin B with the
FICI less of 0.5. This oil could be used as natural antibiotics and may decrease the effective dose of antibiotics.

Keywords

• menthol
• peppermint
• synergism
• antimicrobial activity