Abstract
The aim of this research is to profile the chemical composition of the essential oil (EO) extracted from the aerial parts of
Origanum elongatum
(
O. elongatum
) and to evaluate its antioxidant, antibacterial and insecticidal activities on
Ceratitis capitata
adults. Gas chromatography coupled with mass spectrometry (GC/MS) revealed a total of 27 constituents in EO of
O. elongatum
, which accounted for 99.08% of its constituents. Carvacrol (57.32%) was a main component, followed by
p
-cymene (14.70%) and
γ
-terpinene (9.84%). The antioxidant activity of
O. elongatum
EO was investigated using DPPH (1,1-diphenyl-2-picrylhydrazyl), FRAP (Ferric reducing antioxidant power), and TCA (the total antioxidant capacity) methods. This EO exhibited a remarkable antiradical and reducing power against DPPH (IC
50
= 2.855 ± 0.018μL/mL), FRAP (EC
0.5
= 0.124 ± 0.013µL/mL) and TCA (IC
50
= 14.099 ± 0.389 mg AAE/g of the EO). The antibacterial tests in vitro, using the disc and dilution methods, were carried out on nine pathogenic bacteria isolated from the hospital patients, such as
Enterococcus faecalis
,
Serratia fonticola
,
Staphylococcus aureus, Acinétobacter baumannii, Klebsiella oxytoca
,
Klebsiella pneumoniae sensible
,
E.coli sensible
,
E.coli resistante
, and
Enterobacter aerogenes
. The EO demonstrated a considerable antibacterial activity with minimum inhibitory concentrations (MIC) from 2 to 8 µL/mL against all strains except
Staphylococcus aureus
(MIC = 32 µL/mL). Regarding the insecticidal activity, the fumigation test indicated a high efficacy (100% mortality), and a lethal dose of LD
50
= 17 ± 0.53 μL/L air was found after 24 h of exposureTherefore,
O. elongatum
EO could be utilized as a natural antioxidant, antibiotic and biopesticides.