title: Protective properties of quercetin against DNA damage and oxidative stress induced by methylmercury in rats.
abstract: Aim of the study was to find out whether consumption of quercetin (QC), an abundant flavonoid in the human diet, protects against DNA damage caused by exposure to organic mercury. Therefore, rats were treated orally with methylmercury (MeHg) and the flavonoid with doses that reflect the human exposure. The animals received MeHg (30 μg/kg/bw/day), QC (0.5-50 mg/kg/bw/day), or combinations of both over 45 days. Subsequently, the glutathione levels (GSH) and the activities of glutathione peroxidase (GPx) and catalase (CAT) were determined, and DNA damage was measured in hepatocytes and peripheral leukocytes in single cell gel electrophoresis assays. MeHg decreased the concentration of GSH and the activity of GPx by 17 and 12%, respectively and caused DNA damage to liver and blood cells, while with QC no such effects were seen. When the flavonoid was given in combination with MeHg, the intermediate and the highest concentrations (5.0 and 50.0 mg/kg/bw/day) were found to cause DNA protection; DNA migration was reduced by 54 and 65% in the hepatocytes and by 27 and 36% in the leukocytes; furthermore, the reduction in GSH and GPx levels caused by MeHg treatment was restored. In summary, our results indicate that consumption of QC-rich foods may protect Hg-exposed humans against the adverse health effects of the metal.
authors.affiliation: Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. do Café, s/no, Ribeirão Preto, São Paulo, CEP 14040-903, Brazil.
authors.forename: Gustavo Rafael Mazzaron
authors.initials: GR
authors.lastname: Barcelos
authors.forename: Denise
authors.initials: D
authors.lastname: Grotto
authors.forename: Juliana Mara
authors.initials: JM
authors.lastname: Serpeloni
authors.forename: José Pedro Friedmann
authors.initials: JP
authors.lastname: Angeli
authors.forename: Bruno Alves
authors.initials: BA
authors.lastname: Rocha
authors.forename: Vanessa Cristina
authors.initials: VC
authors.lastname: de Oliveira Souza
authors.forename: Juliana Tanara
authors.initials: JT
authors.lastname: Vicentini
authors.forename: Tatiana
authors.initials: T
authors.lastname: Emanuelli
authors.forename: Jairo Kenupp
authors.initials: JK
authors.lastname: Bastos
authors.forename: Lusânia Maria Greggi
authors.initials: LM
authors.lastname: Antunes
authors.forename: Siegfried
authors.initials: S
authors.lastname: Knasmüller
authors.forename: Fernando
authors.initials: F
authors.lastname: Barbosa
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D002374:Catalase / Q000378:metabolism; D020552:Comet Assay; D004249:DNA Damage / Q000187:drug effects*; D005978:Glutathione / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D022781:Hepatocytes / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D007962:Leukocytes / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D008099:Liver / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D008297:Male; D008767:Methylmercury Compounds / Q000097:blood / Q000493:pharmacokinetics / Q000633:toxicity*; D009153:Mutagens / Q000493:pharmacokinetics / Q000633:toxicity*; D018384:Oxidative Stress / Q000187:drug effects*; D011794:Quercetin / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000975:Antioxidants; D008767:Methylmercury Compounds; D009153:Mutagens; D011794:Quercetin; D002374:Catalase; D005979:Glutathione Peroxidase; D005978:Glutathione; C004925:methylmercuric chloride