The In Vitro Antimicrobial Effects of Lavandula angustifolia Essential Oil in Combination with Conventional Antimicrobial Agents

Abstract

The paper focuses on the in vitro antimicrobial activity of Lavandula angustifolia Mill. (lavender) essential oil in combination with four commercial antimicrobial agents. Stock solutions of chloramphenicol, ciprofloxacin, nystatin, and fusidic acid were tested in combination with L. angustifolia essential oil. The antimicrobial activities of the combinations were investigated against the Gram-positive bacterial strain Staphylococcus aureus (ATCC 6538) and Gram-negative Pseudomonas aeruginosa (ATCC 27858) and Candida albicans (ATCC 10231) was selected to represent the yeasts. The antimicrobial effect was performed using the minimum inhibitory concentration (MIC) microdilution assay. Isobolograms were constructed for varying ratios. The most prominent interaction was noted when L. angustifolia essential oil was combined with chloramphenicol and tested against the pathogen P. aeruginosa (ΣFIC of 0.29). Lavendula angustifolia essential oil was shown in most cases to interact synergistically with conventional antimicrobials when combined in ratios where higher volumes of L. angustifolia essential oil were incorporated into the combination.

Antioxidant and antimicrobial activities of Lavandula angustifolia Mill. field-grown and propagated in vitro

“…Thus far, it has been determined that L. angustifolia oils inhibit the propagation of E. coli (Azar et al 2011, Criste et al 2014, Bacillus subtilis (Prabuseenivasan et al 2006, Azar et al 2011, S. aureus (De Martino et al 2009, Criste et al 2014, Enterococcus faecalis (Stanojević et al 2011, Adaszyńska-Skwirzyńska et al 2014, P. aeruginosa (Niculae et al 2009, Criste et al 2014, Listeria monocytogenes (Rota et al 2004, Valizadeh et al 2015, and of the fungi C. albicans (Rapper et al 2013, Thosar et al 2013, Aspergilloma and Aspergillosis (Uniyal et al 2012).…”

Potential of Herbal Drug and Antibiotic Combination Therapy: A New Approach to Treat Multidrug Resistant Bacteria

“…When placed in various ratios the combination of L. angustifolia and C. sinensis essential oil demonstrated the best antimicrobial effect with synergy identified for all ratios against the microorganisms tested. The combination has shown a greater antifungal effect when placed in various ratios as five of the nine ratios of different oils against C. albicans [42]. Combined therapy is traditionally used to increase antimicrobial activity and reduce toxic effects of agents [43].…”

Rhamnolipids as emulsifying agents for essential oil formulations: Antimicrobial effect against Candida albicans and methicillin-resistant Staphylococcus aureus

“…Lavender (Lavandula angustifolia), a member of the Lamiaceae family, produces an EO that is rich in linalyl acetate and linalool. This oil has been reported to exhibit some antimicrobial activity against pathogenic microorganisms (de Rapper et al, 2013;Hammer et al, 1999a).…”