title: Toxicity and toxin identification in Colomesus asellus, an Amazonian (Brazil) freshwater puffer fish.
abstract: Toxicity and toxin identification in Colomesus asellus, an Amazonian (Brazil) freshwater puffer fish. By using four different techniques--mouse bioassay, ELISA, HPLC and mass spectrometry-we evaluated the toxicity in the extracts of C. asellus, a freshwater puffer fish from the rivers of the Amazon, and identified for the first time the components responsible for its toxicity. The T20G10 monoclonal antibody raised against TTX, and employed in an indirect competitive enzyme immunoassay, showed very low affinity for the C. asellus extracts, indicating that TTX and its analogs are not the main toxic components of the extracts. This antibody was efficient in detecting presence of TTX in a total extract of Sphoeroides spengleri, which is one of the most toxic puffer fish found in the Atlantic coast. Extracts of C. asellus were toxic when administered intraperitonially into mice with an average toxicity of 38.6+/-12 mouse unit (MU)/g, while HPLC analysis indicated a lower toxin content (7.6+/-0 5MU/g). The HPLC profile showed no traces of TTX, but only the presence of PSPs (STX, GTX 2 and GTX 3). These toxins were also confirmed by electrospray ionization mass spectrometry.
authors.affiliation: Department of Physiology, Biosciences Institute, University of São Paulo, Rua do Matão 101, Travessa 14, 05508 900 São Paulo, Brazil. jstolarz@usp.br
authors.forename: Joacir Stolarz
authors.initials: JS
authors.lastname: Oliveira
authors.forename: Solange Cristina Rego
authors.initials: SC
authors.lastname: Fernandes
authors.forename: Carlos Alberto
authors.initials: CA
authors.lastname: Schwartz
authors.forename: Carlos
authors.initials: C
authors.lastname: Bloch
authors.forename: Jorge Alex Taquita
authors.initials: JA
authors.lastname: Melo
authors.forename: Osmindo
authors.initials: O
authors.lastname: Rodrigues Pires
authors.forename: José Carlos
authors.initials: JC
authors.lastname: de Freitas
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004797:Enzyme-Linked Immunosorbent Assay; D051379:Mice; D012530:Saxitoxin / Q000032:analysis* / Q000633:toxicity; D023721:Tetraodontiformes; D013779:Tetrodotoxin / Q000032:analysis* / Q000633:toxicity
chemical_list: D012530:Saxitoxin; D013779:Tetrodotoxin