title: Acute effects of pure cylindrospermopsin on the activity and transcription of antioxidant enzymes in tilapia (Oreochromis                      niloticus) exposed by gavage.
abstract: The cyanobacterial toxin cylindrospermopsin (CYN) is a widely distributed contaminant of freshwater systems with the consequent risk for human and wildlife, particularly fish. However, CYN toxicity data on fish are still scarce. It is known that CYN inhibits glutathione synthesis and this could contribute to oxidative damage. In the present work tilapia (Oreochromis niloticus) were exposed by gavage to 200 and 400 μg/kg bw of pure CYN and sacrificed after 24 h. The activity and relative mRNA expression by real-time PCR of antioxidant enzymes glutathione peroxidase (GPx) and soluble glutathione-S-transferases (sGST) and the sGST protein abundance by Western blot analysis were evaluated in liver and kidney. Also the induction of lipid peroxidation (LPO) was assayed. Results show an increase of LPO products in both organs. Moreover, CYN altered the activity, gene expression and protein abundance of the enzymes, indicating the importance of GPx and sGST in CYN pathogenicity. This is the first time that CYN is reported to affect these enzymes in fish and they have shown to be responsive biomarkers of CYN toxicity.
authors.affiliation: Faculty of Pharmacy, Area of Toxicology, Profesor García González 2, 41012, Seville, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Puerto
authors.forename: Angeles
authors.initials: A
authors.lastname: Jos
authors.forename: Silvia
authors.initials: S
authors.lastname: Pichardo
authors.forename: Daniel
authors.initials: D
authors.lastname: Gutiérrez-Praena
authors.forename: Ana M
authors.initials: AM
authors.lastname: Cameán
mesh_terms: D000470:Alkaloids; D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D001427:Bacterial Toxins; D023681:Cichlids / Q000378:metabolism*; D000087522:Cyanobacteria Toxins; D004798:Enzymes / Q000235:genetics* / Q000378:metabolism*; D005618:Fresh Water; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D005979:Glutathione Peroxidase / Q000235:genetics / Q000378:metabolism; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism; D007668:Kidney / Q000187:drug effects / Q000201:enzymology; D015227:Lipid Peroxidation / Q000187:drug effects; D008099:Liver / Q000187:drug effects / Q000201:enzymology; D060888:Real-Time Polymerase Chain Reaction; D023382:Toxicity Tests, Acute; D014498:Uracil / Q000031:analogs & derivatives* / Q000633:toxicity
chemical_list: D000470:Alkaloids; D000975:Antioxidants; D001427:Bacterial Toxins; D000087522:Cyanobacteria Toxins; D004798:Enzymes; C089595:cylindrospermopsin; D014498:Uracil; D005979:Glutathione Peroxidase; D005982:Glutathione Transferase