Ziziphora tenuior L. essential oil from Dana Biosphere Reserve (Southern Jordan); Chemical characterization and assessment of biological activities.
BACKGROUND
Ziziphora tenuior L. (Lamiaceae) is a medicinal plant in Jordan, which is included in various antimicrobial, antiseptic, expectorant and wound healing preparations. It is used for the treatment of cough, stomach ache, dysentery, fever, uterus infection, gut inflammation and painful menstruation.


OBJECTIVE
The aim of this study was to assess, for the first time, the chemical composition of the essential oil of Z. tenuior originated from southern Jordan and its antifungal effects against several yeasts. Concomitantly, the mechanisms behind the anti-fungal activity against Candida albicans were also disclosed. Since the Z. tenuior traditional uses are related with inflammatory-associated conditions, the putative anti-inflammatory activity of the oil was also unveiled. Importantly, the potential toxicity of pharmacologically active concentrations was screened in different types of mammalian cells.


METHODS
Z. tenuior essential oil, isolated by hydrodistillation, was analyzed by gas chromatography, gas chromatography-mass spectrometry and13C nuclear magnetic resonance spectroscopy. Antifungal activity was evaluated against yeasts, dermatophytes and Aspergillus strains. Germ tube inhibition and biofilm formation assays were evaluated using C. albicans. Assessment of cell viability was made by the MTT assay using different types of mammalian cells, including hepatocytes, keratinocytes and macrophages. The in vitro anti-inflammatory potential of the oil was evaluated by measuring nitric oxide production using lipopolysaccharide-stimulated mouse macrophages.


RESULTS
Oxygen-containing monoterpenes are the main oil compounds: pulegone (46.8%), p-menth-3-en-8-ol (12.5%), isomenthone (6.6%) and 8-hydroxymenthone (6.2%). The highest antifungal activity was against Cryptococcus neoformans, with a MIC value of 0.16µL/mL. The oil revealed an important inhibitory effect on germ tube formation with a filamentation inhibition rate higher than 80% at 0.16µL/mL. The amount of the attached biomass was reduced. Importantly, concentrations devoid of toxicity on several mammalian cell types still displayed anti-inflammatory activity (0.16 and 0.32µL/mL).


CONCLUSIONS
These findings add significant information to the pharmacological activity of Z. tenuior, thus justifying and reinforcing the use of this plant in traditional medicine. Additionally, the antifungal and anti-inflammatory potential of the oil at non-toxic concentrations, opens new avenues for its further exploitation, for instance in health-care product development.
Department of Basic and Applied Sciences, Shouback University College/ Maan College, Al-Balqa Applied University, Al-Salt 19117, Jordan; Department of Pharmaceutical Biology, Institute of Pharmacy and Biochemistry, Johannes Gutenberg University, Staudinger Weg 5, 55128 Mainz, Germany.
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MS
Abu-Darwish
CNC.IBILI/ Faculty of Pharmacy, University of Coimbra, Azinhaga de S. Comba 3000-354 Coimbra, Portugal. Electronic address: celiacabral@ff.uc.pt.
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Cabral
CNC.IBILI/ Faculty of Pharmacy, University of Coimbra, Azinhaga de S. Comba 3000-354 Coimbra, Portugal.
M J
MJ
Gonçalves
CNC.IBILI/ Faculty of Pharmacy, University of Coimbra, Azinhaga de S. Comba 3000-354 Coimbra, Portugal.
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Cavaleiro
CNC.IBILI/ Faculty of Pharmacy, University of Coimbra, Azinhaga de S. Comba 3000-354 Coimbra, Portugal.
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Cruz
Université de Corse-CNRS, UMR 6134 SPE, Equipe Chimie et Biomasse, 20000 Ajaccio, France.
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Paoli
Université de Corse-CNRS, UMR 6134 SPE, Equipe Chimie et Biomasse, 20000 Ajaccio, France.
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F
Tomi
Department of Pharmaceutical Biology, Institute of Pharmacy and Biochemistry, Johannes Gutenberg University, Staudinger Weg 5, 55128 Mainz, Germany.
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Efferth
CNC.IBILI/ Faculty of Pharmacy, University of Coimbra, Azinhaga de S. Comba 3000-354 Coimbra, Portugal.
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Salgueiro
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000737:chemistry / Q000494:pharmacology; D000935:Antifungal Agents / Q000737:chemistry / Q000494:pharmacology; D001230:Aspergillus / Q000187:drug effects; D018533:Biomass; D002176:Candida albicans / Q000187:drug effects; D002460:Cell Line; D045744:Cell Line, Tumor; D003455:Cryptococcus neoformans / Q000187:drug effects; D000081005:Cyclohexane Monoterpenes; D056945:Hep G2 Cells; D006801:Humans; D007597:Jordan; D019686:Lamiaceae / Q000737:chemistry*; D008264:Macrophages / Q000187:drug effects; D051379:Mice; D008826:Microbial Sensitivity Tests / Q000379:methods; D039821:Monoterpenes / Q000737:chemistry / Q000494:pharmacology; D009822:Oils, Volatile / Q000737:chemistry / Q000494:pharmacology*; D010938:Plant Oils / Q000737:chemistry / Q000494:pharmacology*; D013729:Terpenes / Q000737:chemistry / Q000494:pharmacology
D000893:Anti-Inflammatory Agents; D000935:Antifungal Agents; D000081005:Cyclohexane Monoterpenes; D039821:Monoterpenes; D009822:Oils, Volatile; D010938:Plant Oils; D013729:Terpenes; C039648:pulegone; C575995:isomenthone
Anti-inflammatory activity; Antifungal activity; Chemical composition; Cytotoxicity; Essential oil; Ziziphora tenuior