title: An investigation of the role of vitamin E in the protection of mice against microcystin toxicity.
abstract: The presence of cyanobacterial toxins in drinking and recreational waters represents a potential public health risk. Microcystin-LR (MC-LR) is a potent cyclic heptapeptide hepatotoxin produced by the blue-green alga Microcystis aeruginosa. Chemoprotectant studies have indicated that membrane-active antioxidants such as vitamin E may offer protection against microcystin toxicity. This study investigated the effect of vitamin E supplementation on microcystin toxicity in mouse liver. Groups of mice were fed vitamin E supplements (8.33 or 33.3 U/mouse/day) for 4 weeks, with intraperitoneal doses of MC-LR extract (70% LD(50)) every 3 days from day 8. The potential benefits of vitamin E were evaluated based on lipid peroxidation, alanine transaminase (ALT), and glutathione S-transferase (GST) levels. Vitamin E supplementation at 33.3 U/mouse/day offered some protection against lipid peroxidation induced by repeated exposure to MC-LR extract and limited both the toxin-induced increase in ALT leakage and decrease in GST activity. Vitamin E supplementation at 66.6 U/mouse/day significantly increased the time to death and reduced the increase in liver percentage body weight induced in mice given a lethal dose challenge of MC-LR extract. Therefore, vitamin E, taken as a dietary supplement, may have a protective effect against chronic exposure to MC-LR.
authors.affiliation: Department of Biochemistry and Microbiology, University of Port Elizabeth, P.O. Box 1600, Port Elizabeth, 6000, South Africa. bcammg@upe.ac.za
authors.forename: Michelle M
authors.initials: MM
authors.lastname: Gehringer
authors.forename: Sharlene
authors.initials: S
authors.lastname: Govender
authors.forename: Mrinal
authors.initials: M
authors.lastname: Shah
authors.forename: Timothy G
authors.initials: TG
authors.lastname: Downing
mesh_terms: D000818:Animals; D001427:Bacterial Toxins / Q000633:toxicity; D000458:Cyanobacteria / Q000472:pathogenicity*; D005982:Glutathione Transferase / Q000494:pharmacology; D007263:Infusions, Parenteral; D015227:Lipid Peroxidation; D008099:Liver / Q000473:pathology; D008297:Male; D008387:Marine Toxins / Q000633:toxicity; D051379:Mice; D008807:Mice, Inbred BALB C; D052998:Microcystins; D010456:Peptides, Cyclic / Q000633:toxicity*; D011634:Public Health; D011998:Recreation; D014810:Vitamin E / Q000494:pharmacology*; D014881:Water Supply
chemical_list: D001427:Bacterial Toxins; D008387:Marine Toxins; D052998:Microcystins; D010456:Peptides, Cyclic; D014810:Vitamin E; D005982:Glutathione Transferase; C057862:cyanoginosin LR