title: Efficacy and mechanism of action of arachidonic acid in the treatment of hamsters infected with Schistosoma mansoni or Schistosoma haematobium.
abstract: We have recently shown that in vitro and in vivo exposure of Schistosoma mansoni and Schistosoma haematobium to 5-10mM arachidonic acid (ARA) induces parasite surface membrane disintegration and eventual attrition. Here we report on the optimum ARA dose and post-infection treatment time for maximum schistosome demise in hamsters. A series of four experiments for each schistosome species indicated that oral administration of ARA after patency led to a highly significant (P<0.02 to <0.001) reduction in worm burden accompanied by a significant (P<0.05) decrease in worm egg load. ARA-mediated attrition in vivo appeared to be associated with high titres of serum antibodies to tegumental antigens. In support, serum antibodies from patently infected and ARA-treated hamsters readily bound to the surface membrane of ARA-exposed adult worms, as judged by indirect membrane immunofluorescence. More importantly, addition of serum antibodies and peripheral blood mononuclear cells significantly enhanced ARA-mediated adult worm attrition in vitro. These data together show that the schistosomicidal effect of ARA in laboratory animals is enhanced by immune effectors and is highly efficacious and entirely safe.
authors.affiliation: Zoology Department, Faculty of Science, Cairo University, Giza 12613, Egypt. rashika@mailer.eun.eg
authors.forename: Rashika
authors.initials: R
authors.lastname: El Ridi
authors.forename: Hatem
authors.initials: H
authors.lastname: Tallima
authors.forename: Mohamed
authors.initials: M
authors.lastname: Salah
authors.forename: Marwa
authors.initials: M
authors.lastname: Aboueldahab
authors.forename: Omar M
authors.initials: OM
authors.lastname: Fahmy
authors.forename: Mohammad Farhan
authors.initials: MF
authors.lastname: Al-Halbosiy
authors.forename: Soheir S
authors.initials: SS
authors.lastname: Mahmoud
mesh_terms: D000818:Animals; D000947:Antigens, Helminth / Q000378:metabolism; D016718:Arachidonic Acid / Q000008:administration & dosage / Q000494:pharmacology*; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D006224:Cricetinae; D004353:Drug Evaluation, Preclinical; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D007963:Leukocytes, Mononuclear / Q000378:metabolism; D008099:Liver / Q000469:parasitology / Q000473:pathology; D008297:Male; D008647:Mesocricetus; D008855:Microscopy, Electron, Scanning; D010270:Parasite Egg Count; D012548:Schistosoma haematobium / Q000187:drug effects / Q000472:pathogenicity*; D012550:Schistosoma mansoni / Q000187:drug effects / Q000472:pathogenicity*; D012552:Schistosomiasis / Q000188:drug therapy* / Q000469:parasitology; D012556:Schistosomicides / Q000008:administration & dosage / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D000947:Antigens, Helminth; D012556:Schistosomicides; D016718:Arachidonic Acid