Chemical composition, antioxidant potential, and antibacterial mechanism of Bischofia java']javanica ethanol extract against Staphylococcus aureus

This study investigates the chemical composition, antioxidant properties, and antibacterial mechanism of the ethanol extract of Bischofia javanica Blume (BJBE) against Staphylococcus aureus. Using UPLC-ESI-MS analysis, ten compounds were identified, including two sterols, six flavonols, and two phenolic acids, with beta-sitosterol, kaempferol, and gallic acid as the major compounds. BJBE exhibited strong antioxidant activity in ABTS and DPPH free radical scavenging assays. It inhibited the growth of S. aureus in a concentration-dependent manner, with a minimum inhibitory concentration (MIC) of 2.60 mg/mL. The antibacterial mechanisms involved reducing intracellular ATP levels, causing cell membrane depolarization, inducing cytoplasmic leakage, decreasing of bacterial protein content, inhibiting of biofilm formation, and damaging cell membrane. These findings suggest that BJBE has the potential as a natural food preservative or bactericide to effectively address food safety concerns associated with S. aureus in food processing and handling environments.