E Houël1, A M S Rodrigues2, A Jahn-Oyac1, J-M Bessière3, V Eparvier2, E Deharo4,5, D Stien2. 1. CNRS-UMR EcoFoG, Cayenne, French Guiana. 2. CNRS-Institut de Chimie des Substances Naturelles, Gif-sur-Yvette, France. 3. UMR 5076, École Nationale Supérieure de Chimie, Montpellier, France. 4. Université de Toulouse; UPS; UMR 152 Pharma-DEV, Faculté des Sciences Pharmaceutiques, Université Toulouse 3, Toulouse, France. 5. Institut de Recherche pour le Développement (IRD), UMR 152 Pharma-DEV, Toulouse, France.
Abstract
AIMS: We determined the chemical composition and investigated the antifungal activity of Otacanthus azureus (Linden) Ronse essential oil (EO) against a range of dermatophytes alone or in combination with azole antifungals. METHODS AND RESULTS: Aerial parts of the plant were steam-distilled and the obtained oil was analysed by gas chromatography/mass spectrometry and (1) H-NMR. It was shown to be largely composed of sesquiterpenes, with the main component being β-copaen-4-α-ol. Using broth microdilution techniques, this oil was found to have remarkable in vitro antifungal activities. Minimum inhibitory concentrations as low as 4 μg ml(-1) were recorded. The analysis of the combined effect of the O. azureus EO with azoles using chequerboard assays revealed a synergism between the EO and ketoconazole, fluconazole or itraconazole against Trichophyton mentagrophytes. Notably, the O. azureus essential oil showed low cytotoxicity to VERO cells. CONCLUSIONS: The O. azureus essential oil alone or in combination with azoles is a promising antifungal agent in the treatment for human dermatomycoses caused by filamentous fungi. SIGNIFICANCE AND IMPACT OF THE STUDY: There is much interest in the study of essential oils for the discovery of new antimicrobial drugs. This study has highlighted the antidermatophytic activity of the O. azureus EO.
AIMS: We determined the chemical composition and investigated the antifungal activity of Otacanthus azureus (Linden) Ronse essential oil (EO) against a range of dermatophytes alone or in combination with azole antifungals. METHODS AND RESULTS: Aerial parts of the plant were steam-distilled and the obtained oil was analysed by gas chromatography/mass spectrometry and (1) H-NMR. It was shown to be largely composed of sesquiterpenes, with the main component being β-copaen-4-α-ol. Using broth microdilution techniques, this oil was found to have remarkable in vitro antifungal activities. Minimum inhibitory concentrations as low as 4 μg ml(-1) were recorded. The analysis of the combined effect of the O. azureusEO with azoles using chequerboard assays revealed a synergism between the EO and ketoconazole, fluconazole or itraconazole against Trichophyton mentagrophytes. Notably, the O. azureusessential oil showed low cytotoxicity to VERO cells. CONCLUSIONS: The O. azureusessential oil alone or in combination with azoles is a promising antifungal agent in the treatment for human dermatomycoses caused by filamentous fungi. SIGNIFICANCE AND IMPACT OF THE STUDY: There is much interest in the study of essential oils for the discovery of new antimicrobial drugs. This study has highlighted the antidermatophytic activity of the O. azureusEO.
Authors: Kaisarun Akter; Emma C Barnes; Joseph J Brophy; David Harrington; Yaegl Community Elders; Subramanyam R Vemulpad; Joanne F Jamie Journal: Evid Based Complement Alternat Med Date: 2016-08-02 Impact factor: 2.629