Synergistic neurotoxicity induced by methylmercury and quercetin in mice

• Published in: Food and chemical toxicology Vol. 47; no. 3; pp. 645 - 649
• Main Authors: Martins, Roberta de P., Braga, Hugo de C., da Silva, Aline P., Dalmarco, Juliana B., de Bem, Andreza F., dos Santos, Adair Roberto S., Dafre, Alcir L., Pizzolatti, Moacir G., Latini, Alexandra, Aschner, Michael, Farina, Marcelo
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.03.2009; Elsevier
• Subjects: animal models; Animals; antioxidant activity; antioxidants; biochemical compounds; Biological and medical sciences; Chemical and industrial products toxicology. Toxic occupational diseases; Dose-Response Relationship, Drug; Female; females; flavonoids; free radical scavengers; glutathione; glutathione peroxidase; glutathione reductase (NADPH); lipid peroxidation; Medical sciences; Metals and various inorganic compounds; Methylmercury; methylmercury compounds; Methylmercury Compounds - toxicity; Mice; Nervous System - drug effects; neuroprotective effect; Neurotoxicity; Oxidative Stress; plant extracts; Polygala; Polygala sabulosa; Quercetin; Quercetin - toxicity; structure-activity relationships; synergism; Toxicology; Neurotoxicity; Polygala; Methylmercury; Quercetin; Nervous system diseases; Toxicity; Rodentia; Flavonoid; Heavy metal; Polyphenol; Vertebrata; Mammalia; Mouse; Animal; Phenols; Mercury Organic compounds
• ISSN: 0278-6915; 1873-6351
• DOI: 10.1016/j.fct.2008.12.020

Methylmercury (MeHg) is a highly neurotoxic pollutant, whose mechanisms of toxicity are related to its pro-oxidative properties. A previous report showed under in vivo conditions the neuroprotective effects of plants of the genus Polygala against MeHg-induced neurotoxicity. Moreover, the flavonoid quercetin, isolated from Polygala sabulosa, displayed beneficial effects against MeHg-induced oxidative damage under in vitro conditions. In this study, we sought for potential beneficial effects of quercetin against the neurotoxicity induced by MeHg in Swiss female mice. Animals were divided into six experimental groups: control, quercetin low dose (5 mg/kg), quercetin high dose (50 mg/kg), MeHg (40 mg/L, in tap water), MeHg + quercetin low dose, and MeHg + quercetin high dose. After the treatment (21 days), a significant motor deficit was observed in MeHg + quercetin groups. Biochemical parameters related to oxidative stress showed that the simultaneous treatment with quercetin and MeHg caused a higher cerebellar oxidative damage when compared to the individual exposures. MeHg plus quercetin elicited a higher cerebellar lipid peroxidation than MeHg or quercetin alone. The present results indicate that under in vivo conditions quercetin and MeHg cause additive pro-oxidative effects toward the mice cerebellum and that such phenomenon is associated with the observed motor deficit.