Contezolid, a novel oxazolidinone antibiotic, acts as a potential anti-inflammatory agent.

Contezolid, a novel oxazolidinone antibiotic, has comparable or superior antibacterial efficacy and safety to linezolid, now widely used for treating multidrug-resistant Gram-positive bacterial infections. Although numerous studies have investigated the immunomodulatory effects of oxazolidinone antibiotics, the immunomodulatory properties of contezolid remain poorly understood. This study aimed to investigate the anti‑inflammatory effects of contezolid using LPS-stimulated RAW264.7 macrophages. Experimental assessments demonstrated that contezolid significantly suppressed key inflammatory mediators, including nitric oxide and reactive oxygen species, while reducing IL-6 and TNF-α cytokine levels and CD86 concurrently. Functional analysis revealed attenuated phagocytic activity through fluorescence-based bacterial internalization assays and viable bacterial colony counting. Mechanistic studies using qRT-PCR identified transcriptional downregulation of Toll-like receptors, with TLR2 showing particularly pronounced suppression compared to activated controls. These findings indicate that, in addition to its known antimicrobial activity, contezolid also exhibits anti-inflammatory properties.