Treatment of visceral leishmaniasis with sterically stabilized liposomes containing camptothecin

The efficacy of 20(S)-camptothecin (CPT), free and incorporated into steric ally stabilized liposomes, has been investigated in vitro against Leishmani a donovani promastigotes and in vivo in a murine model of visceral leishman iasis. Incubation of L. donovani promastigotes with free or liposomal CPT i nhibited the growth of parasites in a dose-dependent manner. Tissue distrib ution studies revealed that the intraperitoneal administration of liposomal CPT was efficient for the delivery of high drug levels to the liver and sp leen. Treatment of infected mice with intraperitoneal injections of free an d liposomal CPT significantly reduced the parasite loads in the livers by 4 3 and 55%, respectively, compared with the loads for untreated controls. Ho wever, both treatments caused normochromic anemia and neutropenia.