Essential oils Composition, Antimicrobial, Antioxidant, and Synergistic Effects of Ammodaucus leucotrichus and Thymus maroccanus

Abstract

This study investigates the synergistic effects of essential oils (EOs) from two wild Moroccan medicinal and aromatic plants, Ammodaucus leucotrichus and Thymus maroccanus, on enhancing the antioxidant and antimicrobial activities. GC-MS analysis identified carvacrol (75.05%) as the main component of T. maroccanus essential oil, and perillaldehyde (84.19%) and limonene (14.15%) as dominant in that of A. leucotrichus. The antimicrobial efficacy was assessed against Bacillus cereus, Listeria monocytogenes, Candida krusei and Candida parapsilosis. The antimicrobial assays revealed that both individual essential oils and their combinations exhibited significant antimicrobial effects against all the tested strains, with minimal inhibitory concentration (MIC) and minimum microbicidal concentration (MMC) values ranging from 97.65 µg/mL to 1562.5 µg/mL. Additionally, antioxidant potential was evaluated through the DPPH and reducing power (RP) assays, indicating that T. maroccanus essential oil and all the mixtures demonstrated strong antioxidant activity, with IC50 and EC50 values ranging from 0.15 to 0.2 mg/ml for DPPH and 2.32 to 2.41 mg/mL for the RP assay, respectively. These findings highlight the potential of these essential oils and their mixtures as effective natural alternatives to synthetic antimicrobial and antioxidant agents, with promising applications in pharmaceuticals and food industries.