title: Light and scanning electron microscopy study of in vitro effects of artesunate in newly excysted metacercariae of Echinostoma paraensei (Trematoda: Digenea).
abstract: Chemotherapy of food-borne trematodes relies on two drugs, praziquantel and tricabendazole, and there is growing interest in finding alternative therapies. Plant oil extracts have long been used in traditional Chinese medicine as sources of bioactive compounds with antiparasitic activity. Species of the genus Echinostoma are used as good models to test effective compounds against food-borne trematodes. This study evaluated the anthelmintic activity of crude artesunate extracts in vitro on newly excysted metacercariae of Echinostoma paraensei by light and scanning electron microscopy (SEM). The flukes were incubated with 1 μg/mL, 10 μg/mL, 25 μg/mL, 50 μg/mL and 100 μg/mL of artesunate for 4, 12, 24, 48 and 72 h. When the exposure time and concentration of artesunate increased, there were changes in motor activity, tegument damage and death. Blebs and swelling were the most common damages quantified on the tegument. The in vitro study reproduced results described for other immature flukes incubated with artemisinin derivatives. Excysted metacercariae of E. paraensei constitute a good model to study in vitro drug effects.
authors.affiliation: Laboratório de Biologia e Parasitologia de Mamíferos Silvestres Reservatórios, Fundação Oswaldo Cruz, Av. Brasil 4365, Manguinhos, 21040-360, Rio Janeiro, Brazil.
authors.forename: Joyce G R
authors.initials: JG
authors.lastname: Souza
authors.affiliation: Laboratório de Helmintologia Romero Lascasas Porto, Departamento de Microbiologia, Imunologia e Parasitologia, Faculdade de Ciências Médicas, Centro Biomédico, Universidade do Estado do Rio de Janeiro, Av. Prof. Manoel de Abreu 444/5º andar, Vila Isabel, 20511-070, Rio de Janeiro, Brazil.
authors.forename: Eduardo J
authors.initials: EJ
authors.lastname: Lopes Torres
authors.affiliation: Laboratório de Biologia e Parasitologia de Mamíferos Silvestres Reservatórios, Fundação Oswaldo Cruz, Av. Brasil 4365, Manguinhos, 21040-360, Rio Janeiro, Brazil.
authors.forename: Juberlan S
authors.initials: JS
authors.lastname: Garcia
authors.affiliation: Laboratório de Biologia e Parasitologia de Mamíferos Silvestres Reservatórios, Fundação Oswaldo Cruz, Av. Brasil 4365, Manguinhos, 21040-360, Rio Janeiro, Brazil.
authors.forename: Ana Paula N
authors.initials: AP
authors.lastname: Gomes
authors.affiliation: Laboratório de Helmintos Parasitos de Vertebrados, Oswaldo Cruz, Av. Brasil 4365, Manguinhos, Pav. Cardoso Fontes, Sl 56, 21040-360, Rio Janeiro, Brazil.
authors.forename: Rosangela
authors.initials: R
authors.lastname: Rodrigues-Silva
authors.affiliation: Laboratório de Biologia e Parasitologia de Mamíferos Silvestres Reservatórios, Fundação Oswaldo Cruz, Av. Brasil 4365, Manguinhos, 21040-360, Rio Janeiro, Brazil. Electronic address: maldonad@ioc.fiocruz.br.
authors.forename: Arnaldo
authors.initials: A
authors.lastname: Maldonado
authors.affiliation: Laboratório de Helmintologia Romero Lascasas Porto, Departamento de Microbiologia, Imunologia e Parasitologia, Faculdade de Ciências Médicas, Centro Biomédico, Universidade do Estado do Rio de Janeiro, Av. Prof. Manoel de Abreu 444/5º andar, Vila Isabel, 20511-070, Rio de Janeiro, Brazil.
authors.forename: José Roberto
authors.initials: JR
authors.lastname: Machado-Silva
mesh_terms: D000818:Animals; D000980:Antiplatyhelmintic Agents / Q000494:pharmacology*; D037621:Artemisinins / Q000494:pharmacology*; D000077332:Artesunate; D006224:Cricetinae; D004305:Dose-Response Relationship, Drug; D004449:Echinostoma / Q000187:drug effects* / Q000648:ultrastructure; D008647:Mesocricetus; D008855:Microscopy, Electron, Scanning; D013997:Time Factors
chemical_list: D000980:Antiplatyhelmintic Agents; D037621:Artemisinins; D000077332:Artesunate
keywords: Artesunate; Echinostoma paraensei; In vitro; Light microscopy; Morphological alterations; Scanning electron microscopy