Exploring the Essential Oil of <i>Ononis natrix</i> : A Detailed Analysis of Its Chemical Composition, Antioxidant Benefits, and Effectiveness Against Both Antibiotic-Sensitive and Resistant Bacteria

Abstract

Background/Objectives Bacterial infections caused by resistant strains such as Pseudomonas aeruginosa , Staphylococcus aureus , Klebsiella pneumoniae , Enterococcus spp. and Escherichia coli represent a growing threat to human and animal health. In the face of rising resistance, essential oils derived from medicinal plants offer a promising natural alternative. The present study aims to characterize the phytochemical composition and evaluate the antioxidant and antimicrobial activities of the essential oil extracted from the aerial part of Ononis natrix . Methods The phytochemical composition, antioxidant activity and antimicrobial efficacy of the essential oil were assessed using gas chromatography-mass spectrometry (GC-MS), the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and Ferric-Reducing Antioxidant Power (FRAP) assays, as well as the disk diffusion method, supplemented by determining of the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), respectively. Results Our findings revealed that Ononis natrix essential oil contains a high level of oxygenated monoterpenes (45.6%) and oxygenated sesquiterpenes (35.35%). The lowest IC 50 value obtained, of the order of 339 μg/mL, was observed with the reducing power test, thus reflecting a reducing capacity of this oil towards the ferric ion Fe 3+ . In addition, the essential oil showed marked antimicrobial effects against the Candida strains and multi-resistant bacteria tested. Conclusion The findings of the current study demonstrated strong antioxidant and antimicrobial properties of O. natrix , which could potentially provide novel treatments, thus, addressing antibiotic resistance issues in the clinical setting.