lasalocid and sinefungin

Lasalocid, sinefungin, and dehydroepiandrosterone were tested for anticryptosporidial activity with an immunodeficient mouse model at doses that have been reported effective when tested with immunosuppressed rodent models. Small but significant reductions in oocyst excretion were only observed under some conditions with lasalocid and dehydroepiandrosterone, but sinefungin had no effect.

Topics: Adenosine; Animals; Antiprotozoal Agents; Coccidiostats; Cryptosporidiosis; Cryptosporidium parvum; Dehydroepiandrosterone; Immunologic Deficiency Syndromes; Lasalocid; Male; Mice; Mice, Nude; Splenectomy

Cryptosporidium parvum causes life-threatening diarrhoea in immunocompromised, especially AIDS patients and the efficiency of proposed anti-cryptosporidial therapies is limited or doubtful. An immunosuppressed adult rat model of C. parvum infection was developed for screening molecules candidate for curative and preventive activity in human cryptosporidiosis. Among 31 drugs tested, lasalocid (2-10 mg/kg/24 h), and sinefungin (2-10 mg/kg/24 h), exhibited some activity against C. parvum infection. Oral sinefungin therapy resulted in a dose related suppression of oocysts shedding, which correlated with oocyst disappearance from ileum sections and was also efficient in preventing infection. Relapses were observed after discontinuation of curative sinefungin therapy, which suggests that the biliary tract, a major location and parasite reservoir which sustains persisting infection, was not cleared of parasites by the drug. Improved therapeutic procedures with sinefungin (or analogues) will result from current pharmacological studies.

Topics: Adenosine; Animals; Coccidiostats; Cryptosporidiosis; Cryptosporidium parvum; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Feces; Immunocompromised Host; Lasalocid; Male; Rats; Rats, Sprague-Dawley