Anti-inflammatory effects of garenoxacin on IL-8 production and ERK1/2 activation induced by lipopolysaccharides in A549 and THP-1 cells

The anti-inflammatory properties of macrolides have been applied to the treatment of inflammatory airway diseases. Although the anti-inflammatory properties of fluoroquinolones have been reported, no reports are available regarding a newly developed fluoroquinolone, garenoxacin (GRNX). To examine the immunomodulatory effect of GRNX, we examined the transcription and secretion of inflammatory cytokines by human airway epithelial cells and monocytes stimulated with lipopolysaccharide (LPS). A human lung epithelial cell line (A549) and a human monocyte cell line (THP-1) were stimulated with LPS and exposed to different concentrations of GRNX. The transcription and secretion of interleukin 8 (IL-8) in both A549 and THP-1 cells was measured by real-time PCR and an enzyme-linked immunosorbent assay, respectively. Treatment with GRNX significantly inhibited the transcription and secretion of IL-8 induced by LPS-stimulated cells through inhibitory ERK1/2 phosphorylation. GRNX has anti-inflammatory activity through its capacity to alter the secretion of IL-8 from A549 and THP-1 cell lines. Our findings suggest that GRNX is suitable for the treatment of LPS-induced respiratory infection and inflammatory airway diseases.