Notoginsenoside Ft1 enhances the effectiveness of gentamicin against Escherichia coli by interfering with intrinsic antibacterial mechanisms

E. coli is a versatile human commensal bacterium and pathogen that can cause a variety of community-acquired and hospital-acquired infections. Gentamicin is an antibiotic commonly used in clinical settings to treat severe infections caused by E. coli; however, the emergence of resistant pathogens highlights the urgent need for alternative strategies to address this global burden. In this study, we demonstrate that Notoginsenoside Ft1 can prevent the evolution of Gentamicin resistance in E. coli, restore the antibiotic’s efficacy against cells exposed to the antibiotic, and inhibit biofilm formation. Notably, Notoginsenoside Ft1 works in synergy with Gentamicin by interacting with active residues of the AcrAB-TolC efflux pump and dissipating the proton motive force (PMF), thereby disrupting the function of the AcrAB-TolC efflux pump and triggering a vicious cycle that compromises cell membrane integrity and disrupts metabolic homeostasis. Furthermore, various host infection models have demonstrated that the synergistic effects of the two compounds also exhibit significant efficacy in vivo. Notoginsenoside Ft1 serves as an effective adjuvant to Gentamicin and can be used in combination to treat infections caused by AcrAB-TolC positive pathogens. This study provides proof of concept and a starting point for investigating the molecular mechanisms by which Notoginsenoside Ft1 inhibits bacterial efflux pumps. These findings reveal the potential of Notoginsenoside Ft1 as a novel adjuvant to Gentamicin in combating infections caused by highly virulent E. coli.