title: Protective role of vitamin E on the microcystin-induced oxidative stress in tilapia fish (Oreochromis niloticus).
abstract: Microcystins (MCs) are potent hepatotoxins produced by cyanobacteria in water systems that induce oxidative stress in fish. The present study investigated the effect of vitamin E pretreatment on MC-induced oxidative damage in the liver, kidneys, and gills of tilapia fish (Oreochromis niloticus). Groups of fish were fed vitamin E supplements (200 or 700 mg per kilogram of diet) for 7 d or received only commercial fish food and then were exposed to a single oral dose of cyanobacterial cells (120 microg of MC-LR [2:Leu, 4:Arg] per fish), and were sacrificed in 24 h. The potential benefits of vitamin E were evaluated based on lipid peroxidation (LPO), protein oxidation, catalase (CAT, Enzyme Commission [EC] 1.11.1.6), superoxide dismutase (EC 1.15.1.1), glutathione peroxidase (EC 1.11.1.9), glutathione reductase (EC 1.8.1.7), and the ratio of reduced glutathione to oxidized glutathione (GSH/GSSG). Microcystins induced a 1.6-fold increase in LPO values in liver, whereas vitamin E-pretreated fish showed no alteration on this biomarker. Enzyme activities levels were also ameliorated by the chemoprotectant, whereas protein oxidation and GSH/GSSG did not show any significant change. The higher vitamin E dose used proved to have the greater protective effects, particularly on the biomarkers LPO and CAT. The results show that vitamin E could have a potential use as a preventive or therapeutic measure in MC-exposed fish.
authors.affiliation: Area of Toxicology, Faculty of Pharmacy, University of Seville, Seville, Spain.
authors.forename: Ana I
authors.initials: AI
authors.lastname: Prieto
authors.forename: Angeles
authors.initials: A
authors.lastname: Jos
authors.forename: Silvia
authors.initials: S
authors.lastname: Pichardo
authors.forename: Isabel
authors.initials: I
authors.lastname: Moreno
authors.forename: Ana M
authors.initials: AM
authors.lastname: Cameán
mesh_terms: D000818:Animals; D002374:Catalase / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D015227:Lipid Peroxidation; D008297:Male; D052998:Microcystins / Q000633:toxicity*; D018384:Oxidative Stress / Q000187:drug effects*; D013482:Superoxide Dismutase / Q000378:metabolism; D017210:Tilapia / Q000378:metabolism*; D014810:Vitamin E / Q000008:administration & dosage*
chemical_list: D052998:Microcystins; D014810:Vitamin E; C078588:microcystin; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005980:Glutathione Reductase; D005978:Glutathione