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.

Combined toxicity of amorphous silica nanoparticles and methylmercury to human lung epithelial cells

“…The nano-SiO 2 could penetrate cell membrane, accumulate in cytoplasm (Nabeshi et al, 2011). Intracellular nanoparticles or mercury can attack DNA to induce DNA damage (Barcelos et al, 2011;Wadhwa et al, 2011). When the DNA damage is so severe that exceed the cellular intrinsic repair capacity of cells, apoptosis or cell death will occur (Zhang et al, 2008).…”

Effects of genetic polymorphisms on antioxidant status and concentrations of the metals in the blood of riverside Amazonian communities co-exposed to Hg and Pb

“…Experimental studies suggest that MeHg and Pb exposure can lead to a decrease in levels of the antioxidant molecules, such as the tripeptide glutathione (GSH) and the activities of antioxidant enzymes like catalase (CAT), glutathione-peroxidase (GPx) and superoxide dismutase (SOD), which may result in oxidative damage in lipids, proteins and DNA (Barcelos et al, 2011a(Barcelos et al, , 2011bCarocci et al, 2014;Flora et al, 2012;Grotto et al, 2009).…”

Unwanted Interactions Among Psychotropic Drugs and Other Treatments for Autism Spectrum Disorders

“…60,61 For example, quercetin prevented liver toxicity induced by acetaminophen 62 and reduced haloperidol-induced dyskinesia in rodents. 63 Quercetin also prevented methylmercury-induced DNA damage, 64 whereas luteolin prevented mercury and thimerosal-induced inflammatory mediator release from immune cells. 65 Luteolin was recently shown to inhibit microglial activation and is also neuroprotective.…”