Chemical Composition, and Antioxidant and Antimicrobial Activity of Oregano Essential Oil

Abstract

Antimicrobial resistance (AMR) is a global public health problem, and the rapid rise in AMR is attributed to the inappropriate and/or overuse of antibiotics. Therefore, alternative antimicrobial agents, including those of natural origin, are being sought for the development of new drugs. The purpose of our study was to analyze the chemical composition, and antimicrobial and antioxidant activities of four oregano essential oils (OEOs) from Poland, Europe, Turkey and the USA. The antimicrobial activity (AMA) was evaluated using 23 strains, including Gram-positive bacteria, Gram-negative bacteria and Candida species. The antioxidant activity (AA) of essential oils (EOs) was determined by the DPPH method. The main component of the EOs tested was carvacrol (76.64–85.70%). The highest amount of this compound was determined in the Polish OEO. The OEOs we tested showed antimicrobial resistance, which was especially strong against fungi (MIC = 0.06–0.25 mg/mL−1). These products also showed high AA (71.42–80.44%). OEOs high in carvacrol should be the subject of further research as potential antimicrobial and antioxidant agents.

Exploring the Antibacterial Potential of Lamiaceae Plant Extracts: Inhibition of Bacterial Growth, Adhesion, Invasion, and Biofilm Formation and Degradation in Pseudomonas aeruginosa PAO1

“…Last but not least, our IBR analysis identified the ethanolic extracts of S. montana and O. vulgare as highly promising antibacterial agents. This observation is noteworthy as prior studies predominantly emphasized the antibacterial activity of their essential oils [ 50 , 61 , 84 ]. Our findings further reveal the promising antibacterial efficacy of their extracts, shedding light on their potential as a powerful natural defense against various aspects of bacterial infections.…”

“…Previous studies have explored the impact of extracts of Lamiaceae representatives on bacterial growth activity [ 40 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 ]; however, our literature review revealed that current research mainly focuses on the antibacterial properties of essential oils derived from Lamiaceae plants [ 12 , 50 , 60 , 61 , 62 ]. In our study, B. subtilis showed the highest susceptibility to the effects of Lamiaceae extracts, with H. officinalis and S. officinalis ethanolic and S. scardica methanolic extracts demonstrating the most potent growth-inhibitory activity.…”