title: Investigation of animal and algal bioassays for reliable saxitoxin ecotoxicity and cytotoxicity risk evaluation.
abstract: Contamination of water bodies by saxitoxin can result in various toxic effects in aquatic organisms. Saxitoxin contamination has also been shown to be a threat to human health in several reported cases, even resulting in death. In this study, we evaluated the sensitivity of animal (Neuro-2A) and algal (Chlamydomonas reinhardtii) bioassays to saxitoxin effect. Neuro-2A cells were found to be sensitive to saxitoxin, as shown by a 24 h EC50 value of 1.5 nM, which was obtained using a cell viability assay. Conversely, no saxitoxin effect was found in any of the algal biomarkers evaluated, for the concentration range tested (2-128 nM). These results indicate that saxitoxin may induce toxic effects in animal and human populations at concentrations where phytoplankton communities are not affected. Therefore, when evaluating STX risk of toxicity, algal bioassays do not appear to be reliable indicators and should always be conducted in combination with animal bioassays.
authors.affiliation: Department of Chemistry, University of Quebec in Montreal, C.P. 8888, Succ. Centre-Ville, Montreal, Quebec, Canada H3C 3P8.
authors.forename: François
authors.initials: F
authors.lastname: Perreault
authors.forename: Marcelo Seleme
authors.initials: MS
authors.lastname: Matias
authors.forename: Silvia Pedroso
authors.initials: SP
authors.lastname: Melegari
authors.forename: Catia Regina Silva de Carvalho
authors.initials: CR
authors.lastname: Pinto
authors.forename: Edmond Ekué
authors.initials: EE
authors.lastname: Creppy
authors.forename: Radovan
authors.initials: R
authors.lastname: Popovic
authors.forename: William Gerson
authors.initials: WG
authors.lastname: Matias
mesh_terms: D000818:Animals; D059001:Aquatic Organisms / Q000187:drug effects; D001681:Biological Assay; D002460:Cell Line; D016825:Chlamydomonas reinhardtii / Q000187:drug effects*; D019175:DNA Methylation / Q000187:drug effects; D054750:Ecotoxicology; D010788:Photosynthesis / Q000187:drug effects; D045332:Photosystem II Protein Complex / Q000378:metabolism; D010839:Phytoplankton / Q000187:drug effects; D018570:Risk Assessment; D012530:Saxitoxin / Q000633:toxicity*; D018675:Toxicity Tests
chemical_list: D045332:Photosystem II Protein Complex; D012530:Saxitoxin