Abstract
Essential oils (EO) of
Origanum compactum
Benth. (
O. compactum
) are well known for their biological and pharmacological activities. This study aimed to assess the chemical composition, antifungal, insecticidal and repellent activities of EO of
O. compactum
used in the Mediterranean diet. Phytochemical screening was conducted using gas chromatography-mass spectrometry (GC/MS). Antifungal activity was tested by the disc diffusion method followed by a minimal inhibitory concentration (MIC) assay against
Candida albicans (C. albicans), Aspergillus flavus (A. flavus), Aspergillus niger (A. nige)
, and
Fusarium oxysporum (F. oxysporum)
. Repellent potential and toxicity of EO by contact and inhalation were tested against
Callosobruchus maculatus
(
C. maculatus
). The yield of essential oil obtained by hydrodistillation of
O. compactum
was 4.41 ± 0.35%, mainly composed of Carvacrol (38%) and Thymol (31.46%). Regarding antifungal activity, the results revealed a wide antifungal spectrum of the studied EO against the tested strains, which reached 100% growth inhibition, especially against
A. niger
and
C. albicans
even at the lowest MIC values (3.125 μg/mL). Concerning insecticidal activity, the EO caused total mortality of
C. maculatus
adults at a dose of 20 μL/L air with LC
50
value of 5.3 μL/L air. A significant reduction in the number of eggs and emergence was proportionally recorded with increasing doses up to 100% at 20 μL/L air. For repellent activity, the studied EO showed a moderate repellent activity with an average percentage of 39.16%. The outcome of this work revealed that
O. Compactum
EO could be a sustainable and environmentally friendly alternative bioinsecticide and bio-fungicide to replace the chemically synthesized forms.