Synergistic effect of fennel essential oil and hydrogen peroxide on bacterial biofilm

Paweł Kwiatkowski; Bartłomiej Grygorcewicz; Agata Pruss; Bartosz Wojciuk; Stefania Giedrys-Kalemba; Barbara Dołêgowska; Hanna Zielińska-Bliźniewska; Jurek Olszewski; Monika Sienkiewicz; Ewa Kochan

doi:10.5114/ada.2019.83621

Synergistic effect of fennel essential oil and hydrogen peroxide on bacterial biofilm

Postepy Dermatol Alergol. 2020 Oct;37(5):690-694. doi: 10.5114/ada.2019.83621. Epub 2019 Mar 22.

Affiliations

¹ Department of Microbiology, Immunology and Laboratory Medicine, Pomeranian Medical University, Szczecin, Poland.
² Department of Allergology and Respiratory Rehabilitation, 2nd Chair of Otolaryngology, Medical University of Lodz, Lodz, Poland.
³ Department of Otolaryngology and Laryngological Oncology, 2nd Chair of Otolaryngology, Medical University of Lodz, Lodz, Poland.
⁴ Pharmaceutical Biotechnology Department, Medical University of Lodz, Lodz, Poland.

Abstract

Introduction: Staphylococcal biofilm formation significantly challenges wound management. The causes of difficult-to-treat wounds are not only methicillin-resistant staphylococci, but also methicillin-sensitive strains with different patterns of resistance. Bacterial biofilm significantly limits the access and activity of antimicrobials used in dermatological infections.

Aim: To evaluate the synergistic effect of fennel essential oil (FEO) and H₂O₂ on biofilm formation by Staphylococcus aureus (MSSA and MRSA) reference strains.

Material and methods: Minimum inhibitory concentration (MIC) values were determined for FEO and H₂O₂ against S. aureus reference strains by the broth microdilution method. The combined effects of the FEO and H₂O₂ were calculated and expressed in terms of a fractional inhibitory concentration index (FICI) using the checkerboard method. The FEO composition was analyzed by the GC-MS method. The data were analysed by one-way ANOVA.

Results: Decreased MIC values for FEO combined with H₂O₂ were observed in comparison to FEO itself. The combinations of FEO and H₂O₂ determined synergistic effects on all S. aureus reference strains. Subinhibitory concentration of FEO alone and in combination with 0.5 MIC of H₂O₂ significantly decreased the production of biofilm biomass in S. aureus strains and reduced the metabolic activity of attached cells.

Conclusions: Combination of fennel essential oil containing nearly 80% trans-anethole and H₂O₂ represents a potential for further basic and applied research on wound management.

Keywords: H2O2; Staphylococcus aureus; biofilm; fennel essential oil.