Canine visceral leishmaniasis: Comparison of in vitro leishmanicidal activity of marbofloxacin, meglumine antimoniate and sodium stibogluconate

The control of canine leishmaniasis largely depends on the success of treatment. Drugs currently available to treat this disease are toxic and partially effective. The curative effect of marbofloxacin, a third-generation fluoroquinolone developed for veterinarian individual treatment, was evaluated in vitro in the presence of Leishmania infantum promastigotes and dog-monocyte-derived macrophages; meglumine antimoniate and sodium stibogluconate were used as comparative treatments. We observed that the killing of Leishmania promastigotes and intracellular amastigotes by marbofloxacin was dose-dependent. We demonstrated that successful treatment of canine infected macrophages for 48 h was possible with 500 μg/ml of marbofloxacin. Leishmanicidal activity acted through a TNF-α and nitric oxide pathway and correlated with the generation of nitric oxide (NO 2) production by monocytes derived macrophages from infected (23 ± 5 μM) or healthy (21 ± 6 μM) dogs, in comparison with NO 2 concentration in infected/non-treated macrophages (