title: Effects of pine bark extract administered to immunosuppressed adult mice infected with Cryptosporidium parvum.
abstract: The treatment of cryptosporidiosis using pine bark extract (Pycnogenol) in immunosuppressed adult C57BL/6N mice infected with Cryptosporidium parvum was investigated. Five groups of 10 mice/group were used. Groups 1, 2, 3, and 5 served as normal, toxicity, placebo, and positive controls, respectively. Mice in groups 2-5 were immunosuppressed with dexamethasone phosphate administered ad libitum in drinking water at a dosage level of 12 microg/ml. Mice in groups 3-5 were inoculated per os with 10(6) C. parvum oocysts on the day immunosuppression was started. Mice in groups 2 and 4 were treated by administering Pycnogenol orally at 30 mg/kg/day. In group 4, Pycnogenol was first administered on day 3 postinoculation. Of the four groups of mice immunosuppressed with DEXp (groups 2-5), the two groups treated with Pycnogenol (groups 2 and 4) had no premature deaths. The other two groups (groups 3 and 5) had 3 and 4 mice die, respectively, before the experiment ended. Consequently, Pycnogenol was judged to be non-toxic at the dosage level used and even afforded mice some positive health benefits. Fecal oocyst shedding in groups 3-5 was initially detected on day 3 postinoculation. These mice continued to shed oocysts throughout the duration of the 28-day experiment. Oocyst shedding intensities were greater in group 3 and 5 than in group 4. However, histological examination of infected intestinal tissues in groups 3-5 revealed no significant difference with regard to parasite colonization and villus/crypt (V/C) length ratios. As a result, Pycnogenol was determined to be therapeutically effective against C. parvum at 30 mg/kg/day only when measured by fecal oocyst shedding intensity. There was no effect on parasite tissue colonization and V/C ratios in infected mice. We conclude that Pycnogenol is a useful dietary supplement for C. parvum-infected patients by affording some positive health benefits, significantly reduces fecal oocyst shedding, but does not decrease parasite colonization of intestinal tissue.
authors.affiliation: Utah State University, Logan 84322, USA.
authors.forename: H C
authors.initials: HC
authors.lastname: Kim
authors.forename: J M
authors.initials: JM
authors.lastname: Healey
mesh_terms: D000276:Adjuvants, Immunologic; D000818:Animals; D003457:Cryptosporidiosis / Q000188:drug therapy* / Q000276:immunology / Q000469:parasitology / Q000473:pathology; D016785:Cryptosporidium parvum / Q000187:drug effects* / Q000254:growth & development / Q000276:immunology; D003907:Dexamethasone / Q000008:administration & dosage / Q000031:analogs & derivatives*; D004195:Disease Models, Animal; D005260:Female; D005419:Flavonoids / Q000627:therapeutic use*; D007108:Immune Tolerance / Q000276:immunology*; D007166:Immunosuppressive Agents / Q000008:administration & dosage; D051379:Mice; D008810:Mice, Inbred C57BL; D028223:Pinus; D024301:Plant Bark; D010936:Plant Extracts
chemical_list: D000276:Adjuvants, Immunologic; D005419:Flavonoids; D007166:Immunosuppressive Agents; D010936:Plant Extracts; C004180:dexamethasone 21-phosphate; C024070:pycnogenols; D003907:Dexamethasone