Planta Med 2014; 80 - P2O64
DOI: 10.1055/s-0034-1395054

Antifungal activity of essential oils from leaves of Cupressus arizonica varieties glabra and arizonica cultivated in Tunisia

W Khouadja 1, 2, R Oliveira 1, M Hanana 3, A Raies 2, A Dias 1
  • 1CITAB – Centre for the Research and Technology of Agro-Environmental and Biological Sciences, Department of Biology, University of Minho, Campus de Gualtar, 4710 – 057 Braga, Portugal
  • 2Laboratoire des Microorganismes et Biomolécules Actives, Faculté des Sciences de Tunis, Université Tunis El-Manar, 2092 El-Manar II Tunis, Tunisia
  • 3Laboratoire de Physiologie Moléculaire des Plantes, Centre de Biotechnologie de Borj Cédria, Hammam-Lif, Tunisia

The Arizona Cypress (Cupressus arizonica) is widely cultivated in Tunisia as an ornamental tree and for windbreaks in desert areas. The essential oil (EO) of this species has been reported to have larvicidal, antimicrobial and antifungal activities [1]. In this work the antifungal mechanism of the EOs of Cupressus arizonica var. arizonica and var. glabra were studied. EOs were extracted by hydrodistillation and were analyzed by chromatography/mass spectrometry (GC-MS). α-Pinene and umbellulone were the major components in both varieties, however var. arizonica has a higher content of α-pinene. Incubation of Saccharomyces cerevisiae cells (Sc) with EOs caused a loss of viability for both varieties from 4% to 90% in a dose-dependent manner from 0.01 µl/ml up to 0.1 µl/ml. This effect was higher with EO from var. arizonica. To investigate the mechanism of EOs toxicity, Sc mutants affected in the oxidative stress response (yap1), base excision repair DNA pathway (apn1) and nucleotide excision repair of DNA damage induced by UV (rad4), were used. The yap1 and apn1 yeast mutant strains were more sensitive to the EOs than the rad4 mutant and the wild type, suggesting that both EOs cause oxidative stress. Accordingly, all strains displayed a significant increase of fluorescence (measured by flow cytometry) with the redox-sensitive probe dichlorofluorescein diacetate, especially the oxidative stress response-deficient mutants. EO from var. arizonica provoked higher fluorescence than EO from var. glabra, suggesting that the former is more active. This correlates with a higher content of α-pinene in EO from var. arizonica, a known oxidant compound. As expected, oxidative DNA damage (COMET assay) was detected in all strains, the yap1 and apn1 mutants displaying more damage to the EOs than the parental strain. Loss of viability with pure α-pinene correlates with results obtained with the EOs, suggesting that this is a major antifungal component.

Acknowledgements: This work is supported by national funds by FCT – Portuguese Foundation for Science and Technology, under the project PEst-OE/AGR/UI4033/2014.

Keywords: Cupressus arizonica, essential oil, oxidative stress, DNA damage

References:

[1] Ali A, Tabanca N, Demirci B, Baser KH, Ellis J, Gray S, Lackey BR, Murphy C, Khan IA, Wedge DE, Natural Product Communications 2013; 8: 257 – 260.