title: First report about saxitoxins in freshwater fish Hoplias malabaricus through trophic exposure.
abstract: Cyanobacterial waterblooms, such as the saxitoxin (STX) producer Cylindrospermopsis raciborskii, have been a worldwide concern in environmental health. However, the bioaccumulation of this neurotoxin in the trophic chain is not completely known. The aim of the present work was to evaluate STX bioaccumulation through chemical analyses and the toxic and trophic effects using biomarkers in the tropical freshwater fish Hoplias malabaricus. They were fed once every five days with Astyanax sp. before being subjected to intraperitoneal inoculation with STX extract (0.08 μg/100 g) obtained by lysis of toxic C. raciborskii strain (T3). After 20 days the brain was collected for acetylcholinesterase (AChE), superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), glutathione peroxidase (GPx), glutathione (GSH), lipoperoxidation (LPO), protein carbonylation (PCO), and comet assay analysis. The muscle was collected for STX chemical analysis. The activities of SOD and concentrations of PCO and LPO increased. The CAT, GST, and GPx activities decreased. Genotoxicity was observed in the experimental group. STX was not detected in muscle samples. Thus, an oxidative stress was observed in the brain, leading to the damage of lipids, proteins, and DNA. The mechanism of action of the neurotoxin in this subchronic exposure suggests an apoptotic cellular process.
authors.affiliation: Programa de Pós-Graduação em Ecologia e Conservação, Universidade Federal do Paraná, Setor de Ciências Biológicas CEP 81531-990, Caixa Postal 19031, CEP 81531-970, Curitiba-Pr, Brazil.
authors.forename: Cesar A
authors.initials: CA
authors.lastname: da Silva
authors.forename: Eliane T
authors.initials: ET
authors.lastname: Oba
authors.forename: Wanessa A
authors.initials: WA
authors.lastname: Ramsdorf
authors.forename: Valéria F
authors.initials: VF
authors.lastname: Magalhães
authors.forename: Marta M
authors.initials: MM
authors.lastname: Cestari
authors.forename: Ciro Alberto
authors.initials: CA
authors.lastname: Oliveira Ribeiro
authors.forename: Helena C
authors.initials: HC
authors.lastname: Silva de Assis
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D020552:Comet Assay; D004249:DNA Damage; D005068:Eutrophication; D005399:Fishes / Q000378:metabolism*; D020387:Food Chain; D005506:Food Contamination; D005618:Fresh Water; D018482:Muscle, Skeletal / Q000378:metabolism; D009153:Mutagens / Q000032:analysis / Q000493:pharmacokinetics / Q000633:toxicity; D018384:Oxidative Stress; D011042:Poisons / Q000032:analysis / Q000493:pharmacokinetics* / Q000633:toxicity; D012530:Saxitoxin / Q000032:analysis / Q000493:pharmacokinetics* / Q000633:toxicity; D014018:Tissue Distribution; D014329:Tropical Climate
chemical_list: D015415:Biomarkers; D009153:Mutagens; D011042:Poisons; D012530:Saxitoxin