Study of the phytochemical and biological variability of the genus origanum in algeria

Abstract

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.