title: Efficacy of pyrvinium pamoate against Cryptosporidium parvum infection in vitro and in a neonatal mouse model.
abstract: No effective approved drug therapy exists for Cryptosporidium infection of immunocompromised patients. Here we investigated the nonabsorbed anthelmintic drug pyrvinium pamoate for inhibition of the growth of the intestinal protozoan parasite Cryptosporidium parvum. The concentration of pyrvinium that effected 50% growth inhibition in human enterocytic HCT-8 cells by a quantitative alkaline phosphatase immunoassay was 354 nM. For comparison, in the same assay, 50% growth inhibition was obtained with 711 microM paromomycin or 27 microM chloroquine. We used a neonatal mouse model to measure the anti-Cryptosporidium activity of pyrvinium pamoate in vivo. Beginning 3 days after infection, pyrvinium at 5 or 12.5 mg/kg of body weight/day was administered to the treatment group mice for 4 or 6 consecutive days. Nine days after infection, the mice were sacrificed, and drug efficacy was determined by comparing the numbers of oocysts in the fecal smears of treated versus untreated mice. The intensities of trophozoite infection in the ileocecal intestinal regions were also compared using hematoxylin-and-eosin-stained histological slides. We observed a >90% reduction in infection intensity in pyrvinium-treated mice relative to that in untreated controls, along with a substantial reduction in tissue pathology. Based on these results, pyrvinium pamoate is a potential drug candidate for the treatment of cryptosporidiosis in both immunocompetent and immunocompromised individuals.
authors.affiliation: Department of Molecular Microbiology and Immunology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA. dsulliva@jhsph.edu.
authors.forename: Autumn S
authors.initials: AS
authors.lastname: Downey
authors.forename: Curtis R
authors.initials: CR
authors.lastname: Chong
authors.forename: Thaddeus K
authors.initials: TK
authors.lastname: Graczyk
authors.forename: David J
authors.initials: DJ
authors.lastname: Sullivan
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000981:Antiprotozoal Agents / Q000494:pharmacology / Q000627:therapeutic use*; D002460:Cell Line; D003457:Cryptosporidiosis / Q000188:drug therapy* / Q000469:parasitology; D016785:Cryptosporidium parvum / Q000187:drug effects* / Q000254:growth & development; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D011774:Pyrvinium Compounds / Q000494:pharmacology / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D000981:Antiprotozoal Agents; D011774:Pyrvinium Compounds; C024631:pyrvinium