Leptospermum scoparium Essential Oil: Antibacterial Properties, Cyto/Genotoxic Effects, Antioxidant Activity, and Wound-Healing Potential In Vitro.

This study evaluated Leptospermum scoparium, (manuka) essential oil (LSEO, for its antibacterial activity, cyto/genotoxicity, antioxidant potential, and its effects on wound closure, reflecting the growing interest in natural compounds with antimicrobial and potential wound-related cellular effects. Analyses were performed on the human keratinocyte cell line HaCaT. The genotoxic effect and the scratch assay of LSEO on human keratinocytes are described for the first time. The results revealed that LSEO did not induce significant DNA damage in vitro after 24 h of treatment. Moreover, treating HaCaT cells with LSEO increased the total antioxidant status level and enhanced wound closure at a concentration of 0.008 µg/mL. Additionally, the inhibitory effect of LSEO against several multidrug-resistant bacterial strains, including Pseudomonas aeruginosa, Proteus vulgaris, Escherichia coli, Enterobacter cloacae, and Staphylococcus aureus, was investigated. LSEO exhibited strong antibacterial activity, with inhibition zones ranging from 25 to 44 mm. The minimal inhibitory concentration and minimal bactericidal concentration of LSEO ranged from 0.10 to 0.5 μg/mL and from 0.25 to 0.75 μg/mL, respectively. The findings indicate that LSEO exhibits antibacterial activity against the tested multidrug-resistant bacterial isolates and may warrant further investigation as a potential antimicrobial agent.