Strongyloides ratti: in vitro and in vivo activity of tribendimidine.
BACKGROUND
Strongyloidiasis is a truly neglected tropical disease, but its public health significance is far from being negligible. At present, only a few drugs are available for the treatment and control of strongyloidiasis.


RESULTS
We investigated the activity of tribendimidine against third-stage larvae (L(3)) of Strongyloides ratti in vitro and against juvenile and adult stages of the parasite in vivo. S. ratti larvae incubated in PBS buffer containing 10-100 microg/ml tribendimidine died within 24 hours. A single 50 mg/kg oral dose of tribendimidine administered to rats infected with 1-day-old S. ratti showed no effect. The same dose administered to rats harboring a 2-day-old infection showed a moderate reduction of the intestinal parasite load. Three days post-exposure a significant reduction of the immature worm burden was found. Administration of tribendimidine at doses of 50 mg/kg and above to rats harboring mature S. ratti resulted in a complete elimination of the larval and adult worm burden. For comparison, we also administered ivermectin at a single 0.5 mg/kg oral dose to rats infected with adult S. ratti and found a 90% reduction of larvae and a 100% reduction of adult worms.


CONCLUSIONS
Tribendimidine exhibits activity against S. ratti in vitro and in vivo. The effect of tribendimidine in humans infected with S. stercoralis should be assessed.
Keiser
Jennifer
J
Department of Medical Parasitology and Infection Biology, Swiss Tropical Institute, Basel, Switzerland. jennifer.keiser@unibas.ch
Thiemann
Kai
K
Endriss
Yvette
Y
Utzinger
Jürg
J
D000818:Animals; D000871:Anthelmintics / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D007559:Ivermectin / Q000494:pharmacology; D007814:Larva / Q000187:drug effects / Q000502:physiology; D008297:Male; D010655:Phenylenediamines / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D017170:Strongyloides ratti / Q000187:drug effects* / Q000502:physiology; D013322:Strongyloidiasis / Q000469:parasitology
D000871:Anthelmintics; D010655:Phenylenediamines; C056017:tribendimidine; D007559:Ivermectin