title: The in vitro effects of Trolox on methylmercury-induced neurotoxicity.
abstract: Methylmercury (MeHg), an environmental toxicant primarily found in fish and seafood poses a dilemma to both consumers and regulatory authorities given the nutritional benefits of fish consumption vs. possible adverse neurological damage caused by MeHg. The present study addresses whether supplementation with 6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid (Trolox), alters the neuro-oxidative effects of MeHg in C6-glioma and B35-neuronal cell lines. As indicators of cytotoxicity, reduced glutathione (GSH), reactive oxygen species (ROS) and mitochondrial activity (MTT) were measured. The cellular mercury (Hg) content was measured with high resolution-inductively coupled plasma mass spectrometry (HR-ICPMS). The amount of MeHg-induced ROS was significantly reduced (p<0.05) after treatment with 50muM Trolox in C6 glial cell line. However, treatment with Trolox did not induce any significant increase in GSH levels or MTT activity in either of the cell lines. In addition, treatment with Trolox did not induce any significant changes in intracellular MeHg levels. The MeHg and Trolox treated C6 glial cell line differed significantly (p<0.05) from the B35 cell line for MTT, ROS and GSH activity. These findings provide experimental evidence that preincubation with Trolox prevents MeHg-induced ROS generation in C6 glial cell line by quenching of free radicals and not by changes in intracellular GSH or MeHg content.
authors.affiliation: Department of Neuroscience, Norwegian University of Science and Technology, Faculty of Medicine, Olav Kyrresgt. 3, N-7489 Trondheim, Norway. parvinder.kaur@ntnu.no
authors.forename: Parvinder
authors.initials: P
authors.lastname: Kaur
authors.forename: Lars
authors.initials: L
authors.lastname: Evje
authors.forename: Michael
authors.initials: M
authors.lastname: Aschner
authors.forename: Tore
authors.initials: T
authors.lastname: Syversen
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D045744:Cell Line, Tumor; D002839:Chromans / Q000494:pharmacology*; D005910:Glioma / Q000473:pathology; D005978:Glutathione / Q000187:drug effects / Q000378:metabolism; D013058:Mass Spectrometry / Q000379:methods; D020262:Mercury Poisoning, Nervous System / Q000209:etiology / Q000517:prevention & control*; D008767:Methylmercury Compounds / Q000633:toxicity*; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D000975:Antioxidants; D002839:Chromans; D008767:Methylmercury Compounds; D017382:Reactive Oxygen Species; D005978:Glutathione; C010643:6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid