title: Enhanced schistosomicidal efficacy of tartar emetic encapsulated in pegylated liposomes.
abstract: The aim of the present study was to evaluate the ability of liposomes to improve the efficacy of tartar emetic (TA) against established Schistosoma mansoni infection. TA was used as a schistosomicidal drug model and both conventional liposomes (CL) and long-circulating pegylated liposomes (LCL) were evaluated. In the first experiment, TA, either free or encapsulated within CL or LCL, was given intraperitoneally (i.p.) as a single dose of 11 mg Sb/kg to mice experimentally infected with S. mansoni. Only the group treated with LCL showed a significant (55%) reduction in the worm burden, compared to the control groups (untreated or treated with empty LCL). In the second experiment, the efficacy of TA-containing LCL was evaluated at a higher dose (27 mg Sb/kg) by both subcutaneous (s.c.) and i.p. routes. Reduction levels of 67 and 82% were achieved by s.c. and i.p. routes, respectively. Strikingly, all mice survived to this high dose of antimony. This is in contrast with free TA that was lethal in 100% of mice at the same dose. The present work demonstrates that LCL reduce the acute toxicity of TA and effectively deliver this drug to S. mansoni during the late stages of parasite infection.
authors.affiliation: Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, Pampulha, 31270-901 Belo Horizonte, MG, Brazil.
authors.forename: Alan L
authors.initials: AL
authors.lastname: de Melo
authors.forename: Neila M
authors.initials: NM
authors.lastname: Silva-Barcellos
authors.forename: Cynthia
authors.initials: C
authors.lastname: Demicheli
authors.forename: Frédéric
authors.initials: F
authors.lastname: Frézard
mesh_terms: D000818:Animals; D000966:Antimony Potassium Tartrate / Q000008:administration & dosage* / Q000737:chemistry / Q000627:therapeutic use; D003692:Delayed-Action Preparations; D007267:Injections; D007274:Injections, Intraperitoneal; D007279:Injections, Subcutaneous; D007700:Kinetics; D008081:Liposomes; D008297:Male; D051379:Mice; D011092:Polyethylene Glycols; D012555:Schistosomiasis mansoni / Q000188:drug therapy*; D012556:Schistosomicides / Q000008:administration & dosage* / Q000737:chemistry / Q000627:therapeutic use
chemical_list: D003692:Delayed-Action Preparations; D008081:Liposomes; D012556:Schistosomicides; D011092:Polyethylene Glycols; D000966:Antimony Potassium Tartrate