Inhibition of DPP IV is a suggested mechanism of the immunomodulatory effects of sparfloxacin

Sparfloxacin is the first marketed amino difluoroquinolone. It is currently marketed in many countries in the world and used widely for the management of urinary tract or respiratory tract infections. Fluoroquinolones could modulate both cellular and humoral immunity. The results of this study showed that Sparfloxacin could significantly suppress the proliferation of both stimulated Balb/c splenocytes and stimulated murine macrophages. Moreover, the release of the IL-6 from these cells was also suppressed. Interestingly, Sparfloxacin inhibits dipeptidyl peptidase IV enzyme (DPP IV) in a dose dependent manner with an IC50 of 29.6 mu M. These findings suggest that DPP IV inhibition by Sparfloxacin could be one of the mechanisms by which Sparfloxacin exerts its immune-modulatory activities.