title: Induction to oxidative stress by saxitoxin investigated through lipid peroxidation in Neuro 2A cells and Chlamydomonas reinhardtii alga.
abstract: Saxitoxin (STX) is a cyanotoxin, which can cause neurotoxic effects and induce ecological changes in aquatic environments, a potential risk to public and environmental health. Many studies of cytotoxicity on animal cells and algae have been performed, although few compare the toxic effects between the two models. In this sense, we investigated the oxidative stress induced by STX (0.4-3.0 nM) in two different cellular models: Neuro-2A (N2A) cells and Chlamydomonas reinhardtii alga by quantification of malondialdehyde (MDA) levels as indicative of lipid peroxidation (LPO). Also was evaluated the antioxidant defense of these cells systems after exposure to STX by the addition of antioxidants in N2A cells culture, and by the measure of antioxidants enzymes activity in C. reinhardtii cells. The MDA levels of N2A cells increased from 15% to 113% for 0.4 and 3.0 nM of STX, respectively, as compared to control. Superoxide-dismutase and catalase did not appear to protect the cell from STX effect while, in cells treated with vitamin E, the rates of MDA production decreased significantly, except for higher concentrations of STX. No MDA productions were observed in algal cells however some effects on antioxidant enzymes activity were observed when algae were exposed to 3.0 nM STX. Our results indicate that the concentrations of STX that may induce oxidative stress through LPO are different in animal and phytoplankton communities. A combination of algal and animal bioassays should be conducted for reliable assessment of oxidative stress induced by STX.
authors.affiliation: Laboratory of Environmental Toxicology, LABTOX, Department of Sanitary and Environmental Engineering, Campus Universitário Trindade, CEP 88040-970 Florianopolis, SC, Brazil.
authors.forename: Silvia P
authors.initials: SP
authors.lastname: Melegari
authors.forename: François
authors.initials: F
authors.lastname: Perreault
authors.forename: Serge
authors.initials: S
authors.lastname: Moukha
authors.forename: Radovan
authors.initials: R
authors.lastname: Popovic
authors.forename: Edmond E
authors.initials: EE
authors.lastname: Creppy
authors.forename: William G
authors.initials: WG
authors.lastname: Matias
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D016825:Chlamydomonas reinhardtii / Q000187:drug effects / Q000378:metabolism*; D005979:Glutathione Peroxidase / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects*; D008315:Malondialdehyde / Q000378:metabolism; D051379:Mice; D018384:Oxidative Stress / Q000187:drug effects*; D012530:Saxitoxin / Q000633:toxicity*; D013482:Superoxide Dismutase / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D014874:Water Pollutants, Chemical; D012530:Saxitoxin; D008315:Malondialdehyde; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase