## 4 Discussion
Slightly higher MIC results (2.6%) of farnesol were obtained in a study carried out by [PERSON] et al. [60]. The researchers analyzed farnesol and its antibacterial properties against the _S. aureus_ ATCC 43300 strain. However, due to differences in the applied methodology, their results may differ from those obtained in this study. In a study conducted by [PERSON] et al. [60], the initial bacterial concentration was 10\({}^{8}\) cfu/mL, while in this study, the concentration was 10\({}^{6}\) cfu/mL (according to the CLSI recommendations). With regard to eugenol (MIC and MBC = 3.13%) and geraniol (MIC and MBC = 3.13%), similar antibacterial properties were recorded against the analyzed standard strain. According to scientific literature, the MIC and MBC values for these compounds against _S. aureus_ strains (including MRSA strains) are similar and range from 1.0% to 3.5% [61; 62; 63; 64]. Slightly higher and lower MIC and MBC values were observed for the antibacterial activity of \(\beta\)-citronellol and carvacrol. They were 6.25% and 0.78%, respectively. However, these results differ from those obtained by other researchers, i.e., the MIC and MBC against the tested MRSA strains were estimated to be higher than 12.5% [65; 66; 67; 68]. A synergistic effect against the analyzed reference strain was noticed for Braunol with \(\beta\)-citronellol (FICI = 0.18) or carvacrol (FICI = 0.50). In turn, an additive effect was found for the combination of Braunol with eugenol (FICI = 1.00) or geraniol (FICI = 0.63) and Prontoderm Solution with \(\beta\)-citronellol (FICI = 0.53). There are no literature studies on the potential synergistic and additive effects of Braunol (including PVP-I) or Prontoderm Solution (including PHMB) with phytochemicals. These data mainly concern the synergistic impact of, among others, PVP-I with antiseptics (e.g., CHG [69]) or antibiotics (e.g., vancomycin [70]), as well as PHMB with biocides (e.g., bronopol or chlorocresol, i.e., compounds used as preservatives in cosmetics) [71]. The mechanism of action of PVP-I involves the release of free iodine, which then binds to the amino groups of amino acids and disrupts the protein structure [72]. In turn, PHMB acts on ion pumps, enzymes and cell receptors [21]. \(\beta\)-citronellol and carvacrol disrupt the structure of proteins and impair the fluidity of the cell membrane, its permeability and its osmoregulatory ability [68]. Eugenol inhibits lipid peroxidation [73], while geraniol penetrates the cell membrane and interacts with intracellular proteins [74]. Therefore, the observed synergistic and additive effects of these compounds may enhance their destructive nature towards proteins. Nevertheless, further research is required to prove the molecular mechanism of action of these compounds in combination. These studies confirm the fact that the substances of origin have antibacterial properties against MRSA strains, and their combination with selected antiseptics may enhance each other. The direct treatment or care of infected wounds with Braunol in combination with \(\beta\)-citronellol or carvacrol may become an alternative way to fight MRSA infections. This is extremely important, considering the fact that wound infections are also recurrent, e.g., in patients with diabetic foot or after surgery. Such combinations may inhibit resistance to commonly used biocides. However, further studies should be carried out to prove the safety of these substances in combination and a possible molecular mechanism of action against MRSA strains. Among the ingredients of EOs, the strongest effects are those of phenolic compounds such as thymol, carvacrol and eugenol. Eugenol is used in dentistry where it may come into contact with mucous membranes through its release from root canal sealers [75]. [PERSON] et al. [76] found that the mild cytotoxic effect of carvacrol and thymol (inhibitory concentration--IC\({}_{20-40}\)) on human hepatoma or colonic cells had no DNA-damaging effect; moreover, it reduced the level of DNA lesions.