Besifloxacin, a novel fluoroquinolone antimicrobial agent, exhibits potent inhibition of pro-inflammatory cytokines in human THP-1 monocytes.

OBJECTIVES This study was conducted to evaluate the anti-inflammatory effects of besifloxacin, a novel fluoroquinolone under clinical evaluation for treatment of ophthalmic infections. METHODS Cytokine expression in human THP-1 monocytes was stimulated by lipopolysaccharide (LPS), and Luminex technology was used to determine the effect of besifloxacin on LPS-induced cytokine expression. Moxifloxacin, a marketed fluoroquinolone used in ophthalmic infections, was used as the control. RESULTS LPS induced measurable cytokine expression for 14 of the 16 cytokines assayed. Besifloxacin significantly inhibited LPS-stimulated cytokine production in a dose-dependent manner, with a comparable [granulocyte macrophage colony-stimulating factor (GM-CSF), interleukin (IL)-1beta, IL-8, interferon-inducible protein (IP-10), monocyte chemotactic protein-1 (MCP-1) and macrophage inflammatory protein-1alpha (MIP-1alpha)] or better [granulocyte CSF (G-CSF), IL-1alpha, IL-1 receptor antagonist (IL-1ra) and IL-6] potency compared with moxifloxacin. A significant inhibitory effect of besifloxacin was observed at 0.1 mg/L for IL-1alpha, at 1 mg/L for G-CSF, IL-1ra and IL-6 and at 30 mg/L for GM-CSF, IL-12p40, IL-1beta, IL-8, IP-10, MCP-1 and MIP-1alpha. CONCLUSIONS Besifloxacin acts as an anti-inflammatory agent in monocytes in vitro; this attribute may enhance its efficacy in ocular infections with an inflammatory component and warrants further investigation.