Optimization of the Antibacterial Activity of a Three-Component Essential Oil Mixture from Moroccan , , and Using a Simplex-Centroid Design.

Background/objectives: The rise of antibiotic-resistant pathogens has become a global health crisis, necessitating the development of alternative antimicrobial strategies. This study aimed to optimize the antibacterial effects of essential oils (EOs) from , , and , enhancing their efficacy through optimized mixtures.

Methods: This study utilized a simplex-centroid design to optimize the mixture ratios of EOs for maximal antibacterial and antioxidant effectiveness. The chemical profiles of the EOs were analyzed using gas chromatography-mass spectrometry (GC-MS). The antibacterial activity was assessed against , , and using minimum inhibitory concentration (MIC) tests, while antioxidant activity was evaluated through DPPH (2,2-diphenyl-1-picrylhydrazyl), and ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) assays.

Results: The optimized essential oil mixtures demonstrated potent antibacterial activity, with MIC values of 0.097% (/) for , 0.058% (/) for , and 0.250% (/) for . The mixture ratios achieving these results included 76% , and 24% for , and varying proportions for other strains. Additionally, essential oil exhibited the strongest antioxidant activity, with IC values of 84.36 µg/mL (DPPH), and 139.61 µg/mL (ABTS), surpassing both the other EOs and standard antioxidants like BHT and ascorbic acid in the ABTS assay.

Conclusions: The study successfully demonstrates that optimized mixtures of EOs can serve as effective natural antibacterial agents. The findings highlight a novel approach to enhance the applications of essential oils, suggesting their potential use in food preservation and biopharmaceutical formulations. This optimization strategy offers a promising avenue to combat antibiotic resistance and enhance food safety using natural products.