Planta Med 2023; 89(08): 800-807
DOI: 10.1055/a-1891-1119
Biological and Pharmacological Activity
Original Papers

Binary Synergistic Combinations of Lavender and Fennel Essential Oils with Amoxicillin[ # ]

Authors

  • Ayşe Esra Karadağ

    1   Department of Pharmacognosy, School of Pharmacy, Istanbul Medipol University, Beykoz, Istanbul, Turkey
    2   Graduate School of Health Sciences, Anadolu University, Eskişehir, Turkey
  • Ayşegül Çaşkurlu

    1   Department of Pharmacognosy, School of Pharmacy, Istanbul Medipol University, Beykoz, Istanbul, Turkey
    3   Graduate School of Health Sciences, Istanbul University, Istanbul, Turkey
  • Betül Demirci

    4   Department of Pharmacognosy, Faculty of Pharmacy, Anadolu University, Eskişehir, Turkey
  • Fatih Demirci

    4   Department of Pharmacognosy, Faculty of Pharmacy, Anadolu University, Eskişehir, Turkey
    5   Faculty of Pharmacy, Eastern Mediterranean University, Famagusta, N. Cyprus, Mersin 10, Turkey

Abstract

Microbial resistance is an important problem in modern healthcare systems. In addition to drug resistance, the side effects of current antibiotic applications are also known issues. In this present study, binary combinations of amoxicillin with European Pharmacopoeia quality lavender (Lavandula angustifolia) and fennel (Foeniculum vulgare) essential oils were evaluated against human pathogenic microbial strains. The checkerboard method was used to quantify the efficacy of the essential oils in combination with amoxicillin. As an initial result, remarkable in vitro antimicrobial activity was observed at relatively low amoxicillin concentrations using different oil combinations against Staphylococcus aureus ATCC 6538, Enterococcus faecalis ATCC 29212, Bacillus cereus ATCC 14579, Escherichia coli NRRL B-3008, Salmonella typhi (clinical isolate), respectively. Fractional inhibitory concentrations were calculated and interpreted in terms of addition, synergy, antagonism, or indifferent. A synergistic interaction with the combination F. vulgare essential oil and amoxicillin (fractional inhibitory concentration index = 8.05 × 10−4) was observed against the pathogens E. faecalis and Escherichia coli. Both essential oils together and in combination with amoxicillin showed a synergistic effect with possible future applications.

# Dedicated to Professor Dr. Gerhard Franz on the occasion of his 85th birthday.


Supporting Information



Publication History

Received: 05 February 2022

Accepted after revision: 03 July 2022

Accepted Manuscript online:
04 July 2022

Article published online:
28 September 2022

© 2022. Thieme. All rights reserved.

Georg Thieme Verlag KG
Rüdigerstraße 14, 70469 Stuttgart, Germany