Docosahexaenoic acid may act as a neuroprotector for methylmercury-induced neurotoxicity in primary neural cell cultures.
The ability of docosahexaenoic acid (DHA) to modulate methylmercury (MeHg)-induced neurotoxicity was investigated in primary astrocytes and neurons from the cerebellum. Gas chromatography measurements indicated increased DHA content in both cell types after 24h supplementation. After individual or combined treatment with MeHg (10microM) and DHA (30 and 90microM), the cell-associated MeHg measurements were done using (14)C-labelled MeHg. In addition, mitochondrial activity was evaluated by MTT reduction, glutathione (GSH) content was measured with the fluorescent indicator monochlorobimane (MCB) and reactive oxygen species (ROS) were detected with the fluorescent indicator-chloro methyl derivative of di-chloro di-hydro fluorescein diacetate (CMH(2)DCFDA). For all the tested treatments, i.e. DHA, MeHg or DHA+MeHg treatment, the neurons differed significantly (p<0.001) from astrocytes exhibiting increased ROS production and decreased MTT activity. After MeHg and 30microM DHA treatment there were no changes in MTT or GSH content but significant decrease (p<0.001) in ROS was observed in both the cell types when compared to MeHg alone. The cell-associated MeHg measurements indicated reduced MeHg-accumulation in both cell types (p<0.05) upon 30microM DHA exposure. Taken together, this study, for the first time establishes that DHA pretreatment effectively reduces cell-associated MeHg and prooxidant response from MeHg in both cerebellar astrocytes and neurons and thus supports the hypothesis that fish-derived nutrients offer possible neuroprotection from MeHg.
Kaur
Parvinder
P
Department of Neuroscience, Faculty of Medicine, Norwegian University of Science and Technology, Olav Kyrresgt. 3, N-7489 Trondheim, Norway. parvinder.kaur@ntnu.no
Heggland
Ingrid
I
Aschner
Michael
M
Syversen
Tore
T
D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D001253:Astrocytes / Q000187:drug effects; D002247:Carbon Isotopes / Q000378:metabolism; D002478:Cells, Cultured; D002531:Cerebellum / Q000166:cytology; D004281:Docosahexaenoic Acids / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D005227:Fatty Acids / Q000378:metabolism; D005452:Fluoresceins; D005978:Glutathione / Q000378:metabolism; D008767:Methylmercury Compounds / Q000378:metabolism / Q000633:toxicity*; D051379:Mice; D009474:Neurons / Q000187:drug effects*; D017382:Reactive Oxygen Species / Q000378:metabolism; D013778:Tetrazolium Salts; D013844:Thiazoles
D002247:Carbon Isotopes; D005227:Fatty Acids; D005452:Fluoresceins; D008767:Methylmercury Compounds; D017382:Reactive Oxygen Species; D013778:Tetrazolium Salts; D013844:Thiazoles; C029569:diacetyldichlorofluorescein; D004281:Docosahexaenoic Acids; C022616:thiazolyl blue; D005978:Glutathione