In the present work we report for what we believe to be the first time the antifungal activity and mechanism of action of the essential oils of Lavandula viridis from Portugal. The essential oils were isolated by hydrodistillation and analysed by GC and GC/MS. The MIC and the minimal lethal concentration (MLC) of the essential oil and its major compounds were determined against several pathogenic fungi. The influence of subinhibitory concentrations of the essential oil on the dimorphic transition in Candida albicans was also studied, as well as propidium iodide and FUN-1 staining of Candida albicans cells by flow cytometry following short treatments with the essential oil. The oils were characterized by a high content of oxygen-containing monoterpenes, with 1,8-cineole being the main constituent. Monoterpene hydrocarbons were present at lower concentrations. According to the determined MIC and MLC values, the dermatophytes and Cryptococcus neoformans were the most sensitive fungi (MIC and MLC values ranging from 0.32 to 0.64 µl ml−1), followed by Candida species (at 0.64–2.5 µl ml−1). For most of these strains, MICs were equivalent to MLCs, indicating a fungicidal effect of the essential oil. The oil was further shown to completely inhibit filamentation in Candida albicans at concentrations well below the respective MICs (as low as MIC/16). Flow cytometry results suggested a mechanism of action ultimately leading to cytoplasmic membrane disruption and cell death. Our results show that L. viridis essential oils may be useful in the clinical treatment of fungal diseases, particularly dermatophytosis and candidosis, although clinical trials are required to evaluate the practical relevance of our in vitro research.
CavaleiroC.,
SalgueiroL. R.,
MiguelM. G.,
Proença da CunhaA.2004; Analysis by gas chromatography-mass spectrometry of the volatile components of Teucrium lusitanicum and Teucrium algarbiensis
. J Chromatogr A 1033:187–190 [View Article][PubMed]
DadalioğluI.,
EvrendilekG. A.2004; Chemical compositions and antibacterial effects of essential oils of Turkish oregano (Origanum minutiflorum), bay laurel (Laurus nobilis), Spanish lavender (Lavandula stoechas L.), and fennel (Foeniculum vulgare) on common foodborne pathogens. J Agric Food Chem 52:8255–8260 [View Article][PubMed]
González-ColomaA.,
Martín-BenitoD.,
MohamedN.,
García-VallejoM. C.,
SoriaA. C.2006; Antifeedant effects and chemical composition of essential oils from different populations of Lavandula luisieri L. Biochem Syst Ecol 34:609–616 [View Article]
KorochA. R.,
JulianiH. R.,
ZygadloJ. A.2007; Bioactivity of essential oils and their components. In Flavours and Fragrances. Chemistry, Bioprocessing and Sustainability pp. 87–115 Edited by
BergerR. G.
Berlin, Heidelberg: Springer-Verlag;
MarichalP.,
GorrensJ.,
Van CutsemJ.,
Vanden BosscheH.1986; Culture media for the study of the effects of azole derivatives on germ tube formation and hyphal growth of C. albicans
. Mykosen 29:76–81[PubMed][CrossRef]
MatosF.,
MiguelM. G.,
DuarteJ.,
VenâncioF.,
MoiteiroC.,
CorreiaA. I. D.,
FigueiredoA. C.,
BarrosoJ. G.,
PedroL. G.2009; Antioxidant capacity of the essential oils from Lavandula luisieri, L. stoechas subsp. lusitanica, L. stoechas subsp. lusitanica x L. luisieri and L. viridis grown in Algarve (Portugal). JEOR 21:327–336[CrossRef]
MillardP. J.,
RothB. L.,
ThiH. P.,
YueS. T.,
HauglandR. P.1997; Development of the FUN-1 family of fluorescent probes for vacuole labeling and viability testing of yeasts. Appl Environ Microbiol 63:2897–2905[PubMed]
MoonT.,
WilkinsonJ. M.,
CavanaghH. M. A.2006; Antibacterial activity of essential oils, hydrosols and plant extracts from Australian grown Lavandula spp. Int J Aromatherapy 16:9–14 [View Article]
Pérez-ParraA.,
MuñozP.,
GuineaJ.,
Martín-RabadánP.,
GuembeM.,
BouzaE.2009; Is Candida colonization of central vascular catheters in non-candidemic, non-neutropenic patients an indication for antifungals?. Intensive Care Med 35:707–712 [View Article][PubMed]
PerrucciS.,
MacchioniG.,
CioniP. C.,
FlaminiG.,
MorelliI.,
TacciniF.1996; The activity of volatile compounds from Lavandula angustifolia against Psoroptes cuniculi
. Phytother Res 10:5–8 [View Article]
PintoE.,
Vale-SilvaL.,
CavaleiroC.,
SalgueiroL.2009; Antifungal activity of the clove essential oil from Syzygium aromaticum on Candida, Aspergillus and dermatophyte species. J Med Microbiol 58:1454–1462 [View Article][PubMed]
SalgueiroL. R.,
PintoE.,
GonçalvesM. J.,
Pina-VazC.,
CavaleiroC.,
RodriguesA. G.,
PalmeiraA.,
TavaresC.,
Costa-de-OliveiraS.,
Martinez-de-OliveiraJ.2004; Chemical composition and antifungal activity of the essential oil of Thymbra capitata
. Planta Med 70:572–575 [View Article][PubMed]
ZuzarteM.,
GonçalvesM. J.,
CavaleiroC.,
DinisA. M.,
CanhotoJ. M.,
SalgueiroL. R.2009; Chemical composition and antifungal activity of the essential oils of Lavandula pedunculata (Miller) Cav. Chem Biodivers 6:1283–1292 [View Article][PubMed]