Abstract
The emergence and prevalence of methicillin-resistant Staphylococcus aureus (MRSA) severely compromises conventional β-lactam antibiotics efficacy and poses an extensive global health challenge. Given the close relationship between docosahexaenoic acid (DHA) and metabolic alterations, this study aimed to reveal the novel function of DHA to potentiate β-lactam antibiotics activity through a lipid peroxidation mechanism. Additionally, DHA exhibited significant inhibitory effects on the catalytic function of β-lactamase through interactions with active residues. Herein, the dual-faceted mechanisms of perturbation of lipid metabolism and β-lactamase catalytic inhibition achieved the potentiated antibacterial efficacy of β-lactam antibiotics in combination with DHA against MRSA. Furthermore, to enhance the pharmacodynamic performance and stability of DHA, amoxicillin and DHA co-loaded nanoemulsions (Amo/DHA-NEs) were prepared via high-energy emulsification. Intriguingly, we found that Amo/DHA-NEs effectively rescued MRSA-induced infections in the murine infection models, as evidenced by the superior bacterial clearance and mitigated inflammation. Collectively, this work reveals a potentially exploitable link between DHA-driven metabolic reprogramming and β-lactams resistance, and we propose combination therapies of DHA and β-lactams targeting the emerging threat of MRSA infections.