Antibacterial Activity and Mechanism of Ludian Green Pepper (Z. schinifolium) Essential Oils against Staphylococcus aureus

To further reveal the antibacterial mechanism of Zanthoxylum schinifolium essential oils (ZSEOs) against Staphylococcus aureus (SA), the ZSEOs were extracted from Ludian green pepper by supercritical CO₂ extraction method, its components were identified by gas chromatography-mass spectrometry (GC-MS). Furthermore, the antibacterial mechanism of ZSEOs on SA was studied by bacterial growth and reproduction, wall membrane damage, interaction with DNA and protein, and energy metabolism, based on the evaluation of SA antibacterial activity. The results showed that 65 volatile components were found in ZSEOs, and linalool was one of key components. The minimum inhibitory concentration (MIC) and minimum bacterial concentration (MBC) of SA were 6.25 and 12.5 μL/mL, respectively, and the diameter of the inhibition zone was 11.67±0.55 mm. When SA was treated with ZSEOs, the surface hydrophobicity of SA could be increased, while the Zeta potential value decreased, it brought about damaging to the wall membrane and leaking of alkaline phosphatase and protein macromolecules in SA. In addition, SDS-PAGE electrophoresis, UV absorption spectroscopy, and molecular docking simulation experiments demonstrated that SA could be inhibited by ZSEOs affecting the nucleic acid metabolism of bacterial cells, interfering with the normal physiological functions and energy supply of proteins in SA, it might be attributed to ZSEOs and their main component linalool bound to DNA and interacted with proteins. Taken together, ZSEOs possessed potential antibacterial effects on SA, due to it induced SA wall membrane damage to leak contents, and affected SA physiological metabolism by interacting with nucleic acids and proteins.