The Roles of Farnesol and Farnesene in Curtailing Antibiotic Resistance

In the extensive domain of “biotechnology and drug development for targeting human diseases”, essential oils have long been revered for their therapeutic potential. Among these, farnesol and farnesene stand out due to their pharmacological attributes. As the challenge of antibiotic resistance intensifies, the scientific community is increasingly exploring the potential of these traditional remedies. Using the KirbyBauer agar diffusion method, a qualitative assessment was conducted on two grampositive and two gram-negative bacterial strains. The broth microdilution technique further determined the Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC), and the sensitizing impacts of these compounds. Both farnesol and farnesene exhibited antibacterial efficacy against all evaluated strains. Their synergistic potential was highlighted when combined with clavulanic acid, cefuroxime, and cefepime. Among these combinations, farnesene paired with cefepime showed pronounced efficacy against Escherichia coli 82 MR, with an MIC of 0.47 μg/mL. In contrast, in the investigation of Staphylococcus aureus 23MR, it was observed that this particular strain exhibited an increased sensitivity when exposed to combinations containing farnesol. Notably, the Minimum Inhibitory Concentration (MIC) was determined to be 0.03 µg/mL in the presence of both antibiotic agents. To gain deeper molecular insights, docking experiments were performed with the βlactamases of E. coli and S. aureus, focusing on the most effective combinations. All tested compounds—cefuroxime, cefepime, farnesene, and farnesol—acted as noncompetitive inhibitors, suggesting their potential mechanisms of action.