title: Effects of sub-acute exposure to TiO2, ZnO and Al2O3 nanoparticles on oxidative stress and histological changes in mouse liver and brain.
abstract: Nanomaterials are at the leading edge of the rapidly developing field of nanotechnology. However the information regarding toxicity of these nanoparticles on humans and environment is still deficient. The present study investigated the toxic effects of three metal oxide nanoparticles, TiO2, ZnO and Al2O3 on mouse erythrocytes, brain and liver. Male mice were administered a single oral dose of 500 mg/kg of each nanoparticles for 21 consecutive days. The results suggest that exposure to these nano metallic particles produced a significant oxidative stress in erythrocyte, liver and brain as evident from enhanced levels of Reactive Oxygen Species (ROS) and altered antioxidant enzymes activities. A significant increase in dopamine and norepinephrine levels in brain cerebral cortex and increased brain oxidative stress suggest neurotoxic potential of these nanoparticles. Transmission electron microscopic (TEM) analysis indicated the presence of these nanoparticles inside the cytoplasm and nucleus. These changes were also supported by the inhibition of CuZnSOD and MnSOD, considered as important biomarkers of oxidative stress. The toxic effects produced by these nanoparticles were more pronounced in the case of zinc oxide, followed by aluminum oxide and titanium dioxide, respectively. The present results further suggest the involvement of oxidative stress as one of the main mechanisms involved in nanoparticles induced toxic manifestations.
authors.affiliation: Division of Regulatory Toxicology, Defence Research and Development Establishment , Gwalior , India.
authors.forename: Rupal
authors.initials: R
authors.lastname: Shrivastava
authors.forename: Saimah
authors.initials: S
authors.lastname: Raza
authors.forename: Abhishek
authors.initials: A
authors.lastname: Yadav
authors.forename: Pramod
authors.initials: P
authors.lastname: Kushwaha
authors.forename: Swaran J S
authors.initials: SJ
authors.lastname: Flora
mesh_terms: D000537:Aluminum Oxide / Q000008:administration & dosage / Q000633:toxicity*; D000818:Animals; D001921:Brain / Q000187:drug effects / Q000473:pathology; D002540:Cerebral Cortex / Q000187:drug effects / Q000473:pathology; D004912:Erythrocytes / Q000187:drug effects / Q000473:pathology; D008099:Liver / Q000187:drug effects / Q000473:pathology; D008297:Male; D053768:Metal Nanoparticles / Q000633:toxicity*; D051379:Mice; D046529:Microscopy, Electron, Transmission; D018384:Oxidative Stress / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000378:metabolism; D014025:Titanium / Q000008:administration & dosage / Q000633:toxicity*; D015034:Zinc Oxide / Q000008:administration & dosage / Q000633:toxicity*
chemical_list: D017382:Reactive Oxygen Species; C009495:titanium dioxide; D014025:Titanium; D000537:Aluminum Oxide; D015034:Zinc Oxide
keywords: Al2O3; TiO2; ZnO; metal oxides nanoparticles; morphological changes; nanotoxicity; oxidative stress