The antimicrobial effect and mechanism of the Artemisia argyi essential oil against bacteria and fungus

Artemisia argyi is a traditional Chinese herb with antibacterial, antifungal, and antitumor activities. The essential oil of Artemisia argyi was extracted using the steam distillation method in this study. The chemical composition of the essential oil was analyzed using the gas chromatography–mass spectrometry method. Agar disc diffusion and double-broth dilution assays were used to detect the antimicrobial activity of the essential oil. Subsequently, the antimicrobial mechanisms were explored through cytomembrane permeability assay and electron microscopy. Based on gas chromatography–mass spectrometry analysis, 25 compounds were detected, including 13.76% cineole, 6.77% terpinen-4-ol, 6.68% 3-dione, 1,7,7-trimethyl-, 4.07% 3-cyclohexen-1-ol, 4-methyl-1-(1-methylethyl)-acetate, 3.58% 1-isopropyl-2-methylbenzene, and 1.58% g-terpinene. The essential oil was tested for antimicrobial activity, and the IC 50 values for Staphylococcus aureus , Escherichia coli , Bacillus subtilis , Listeria monocytogenes , Pseudomonas aeruginosa , Streptococcus pneumoniae , and Candida albicans were determined to be 25.51 ± 2.29, 49.53 ± 0.86, 52.40 ± 1.49, 52.76 ± 1.60, 73.99 ± 1.38, 65.52 ± 0.95, and 214.98 ± 3.27 μg mL −1 , respectively. For essential oil interaction with cytoderm, the microorganisms treated by 1 × IC 50 and 2 × IC 50 concentration of essential oil both represented positive test results. Additionally, the alkaline phosphatase levels showed a direct correlation with concentration and treatment duration (range from 0 to 8 h). The interaction between essential oils and the cytomembrane was investigated by examining samples containing one of three test strains ( Staphylococcus aureus , Escherichia coli , and Candida albicans ), essential oil, and voltage-sensitive fluorescent dye disc35. The results demonstrated a significant increase in fluorescence levels within the solution upon introduction of the essential oil-treated strains. The findings of our research suggest that the essential oil disrupts the cytoderm and cytomembrane, thereby exhibiting antimicrobial activity.