Sanguinarine-induced proteomic changes in methicillin-resistant <i>Staphylococcus aureus</i>

The escalating threat of methicillin-resistant <i>Staphylococcus aureus</i> (MRSA) infections, coupled with the dwindling efficacy of current antibiotics, highlights the urgent need for novel antimicrobial agents.In this study, we demonstrate that sanguinarine – a plant-derived benzophenanthridine alkaloid – exerts potent antibacterial activity against MRSA, with a minimum inhibitory concentration (MIC) of 20 mg/L. To elucidate the molecular mechanisms underlying its antibacterial effects, we conducted a comprehensive, time-resolved proteomic analysis of MRSA upon sanguinarine exposure, quantifying a total of 1,037 proteins, among which significant alterations were observed at each time point over a 120-min treatment period. Proteomic profiling combined with fuzzy C-means clustering revealed distinct temporal response patterns. Upregulated proteins were enriched in pathways related to nucleotide excision repair and central metabolism, suggesting adaptive responses to DNA damage and metabolic stress. In contrast, downregulated proteins were primarily involved in critical cellular processes such as cell division, iron acquisition, RNA turnover, and protein synthesis, indicating a disruption of bacterial growth and homeostasis.These findings provide systems-level insights into the multifaceted antibacterial actions of sanguinarine and support its potential as a promising lead compound for the development of novel therapeutics targeting drug-resistant bacterial infections. The escalating threat of methicillin-resistant <i>Staphylococcus aureus</i> (MRSA) infections, coupled with the dwindling efficacy of current antibiotics, highlights the urgent need for novel antimicrobial agents. In this study, we demonstrate that sanguinarine – a plant-derived benzophenanthridine alkaloid – exerts potent antibacterial activity against MRSA, with a minimum inhibitory concentration (MIC) of 20 mg/L. To elucidate the molecular mechanisms underlying its antibacterial effects, we conducted a comprehensive, time-resolved proteomic analysis of MRSA upon sanguinarine exposure, quantifying a total of 1,037 proteins, among which significant alterations were observed at each time point over a 120-min treatment period. Proteomic profiling combined with fuzzy C-means clustering revealed distinct temporal response patterns. Upregulated proteins were enriched in pathways related to nucleotide excision repair and central metabolism, suggesting adaptive responses to DNA damage and metabolic stress. In contrast, downregulated proteins were primarily involved in critical cellular processes such as cell division, iron acquisition, RNA turnover, and protein synthesis, indicating a disruption of bacterial growth and homeostasis. These findings provide systems-level insights into the multifaceted antibacterial actions of sanguinarine and support its potential as a promising lead compound for the development of novel therapeutics targeting drug-resistant bacterial infections.