Pharmacodynamic basis and mechanism of action of processing waste from Sophora flavescens against multidrug-resistant methicillin-sensitive Staphylococcus aureus

Excessive antibiotic use in livestock production and medical treatment has accelerated the proliferation of Methicillin-Resistant Methicillin-Sensitive Staphylococcus aureus (MR-MSSA), posing a serious threat to healthcare facilities, public environments, and food systems. Sophora flavescens, employed in traditional medicine and functional food formulations for its antimicrobial properties, generates processing waste (SPW) during production. In this study, using HPLC-DAD, SMART analysis, and activity screening, we identified the tissue-specific distribution of S. flavescens and its antibacterial constituents, confirming that SPW effectively substitutes for root bark. Both SPW and its isolated compound, kushenol F (KF), demonstrated rapid bacterial elimination, biofilm inhibition, and low cytotoxicity. Mechanistic studies revealed that SPW or KF exert strong membrane-targeting effects by binding to bacterial phospholipids, causing proton motive force dissipation and membrane fluidity disturbances via a unique mode of action. This disruption increased leakage of ROS, ATP, proteins, and DNA, while reducing metabolic activity. Transcriptomics indicated KF impairs bacterial adhesion, biofilm formation, immune evasion, and membrane transport, with ABC transporter ATP-binding protein as a potential target. Notably, SPW or KF exhibited potent antibacterial and anti-inflammatory effects in vivo , promoting infected wound healing comparably to vancomycin. Collectively, these findings highlight KF as a promising lead compound for anti-MR-MSSA therapy and support SPW utilization. • The distribution of secondary metabolites in S. flavescens exhibits specificity. • The S. flavescens processing waste (SPW) is enriched in isopentenyl flavonoids. • SPW and kushenol F (KF) target the phospholipid components of the bacterial cell membrane. • SPW and KF dose-dependently shifted bacterial membrane proton force from hyperpolarization to depolarization. • SPW and KF exhibit notable antibacterial and anti-inflammatory effects in vivo .