Sitafloxacin Inhibits TNFα Release from Monocytic THP-1 Cells Stimulated by LPS

Sepsis is a systemic reaction to infection and excessive production of inflammatory cytokines and chemokines. It sometimes results in septic shock. The present study was designated to find out which quinolone antibiotic reduces TNFα production the most and to elucidate its mechanisms. We examined which quinolone antibiotic reduced TNFα production from THP-1 cells stimulated by lipopolysaccharide (LPS). Then, we examined the mechanism of inhibition of TNFα production by the antibiotic. STFX most effectively reduced TNFα concentrations within LPS-stimulated THP-1 cells supernatant. STFX suppressed TNFα production in a dose-dependent manner. We found that STFX did not inhibit the NF-kB, ERK, or p38 pathways, nor did it inhibit the production of TNFα mRNA. The percentage of intracellular TNFα was increased in cells stimulated by LPS and with STFX compared to that of cells stimulated by LPS alone. In conclusion, one of the mechanisms reducing TNFα production from LPS-stimulated THP-1 cells treated with STFX involves inhibition of TNFα release from these cells. STFX has a broad antimicrobial spectrum for gram-positive, gram-negative, and anaerobic bacteria, and may be effective for treating sepsis by both killing bacteria and suppressing inflammation.