Résumé:
Abstract
This research aims to valorize Algeria's endemic medicinal and aromatic plants by exploring the phytochemical and biological variability of three Origanum populations: O. floribundum (from Blida and Guelma) and O. glandulosum (from Jijel). Essential oils were extracted using hydrodistillation, analyzed via GC-MS, and assessed for their acaricidal, antioxidant, and anti-inflammatory activities.
The essential oil yields were 2.9% (O. floribundum G), 1.5% (O. glandulosum), and 0.9% (O. floribundum B). Chemical analysis revealed a predominance of carvacrol in all three populations: 43.04% in O. floribundum B, 40% in O. floribundum G, and 29.93% in O. glandulosum. O. glandulosum also exhibited high levels of γ-terpinene (25.48%), thymol (12%), and p-cymene (15.14%). In contrast, O. floribundum showed significant concentrations of cis-sabinene hydrate (31.56% in Blida, 22.21% in Guelma) and cis-β-ocimene (24.44% in Guelma, 13.76% in Blida).
Among the three tested concentrations, preparations with 2% of Origanum floribundum essential oils demonstrated strong acaricidal activity: 76% for O. floribundum G, 75% for O. floribundum B, surpassing the chemical treatment Carvacrol at 73%. However, O. glandulosum was less effective at the same dose, showing 57%.
The antioxidant activity, measured using the DPPH assay, revealed IC50 values of 54.4 μg/mL (O. floribundum B), 66.7 μg/mL (O. floribundum G), and 60.4 μg/mL (O. glandulosum), demonstrating a significant ability to neutralize free radicals, though less effective than ascorbic acid (4.43 μg/mL).
Finally, the in vivo anti-inflammatory activity, evaluated using the carrageenan-induced paw edema method, showed maximum reductions of 78.25% (O. floribundum G at 100 mg/kg) and 64.05% (O. floribundum B at 100 mg/kg), while O. glandulosum achieved only 57.37% at the same dose.
These findings highlight the strong potential of Origanum essential oils, particularly O. floribundum, for various biological applications, contributing to the valorization of Algerian plant resources.
