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J Nanopart Res (2015) 17:49 DOI 10.1007/s11051-015-2868-x
RESEARCH PAPER
Titanium oxide (TiO2) nanoparticles in induction of apoptosis and inammatory response in brain
Ramovatar Meena Sumit Kumar R. Paulraj
Received: 25 August 2014 / Accepted: 8 January 2015 Springer Science+Business Media Dordrecht 2015
Abstract The ever increasing applications of engineered nanoparticles in 21st century cause serious concern about its potential health risks on living being. Regulatory health risk assessment of such particles has become mandatory for the safe use of nanomaterials in consumer products and medicines. In order to study the mechanism underlying the effects of nano-TiO2 (TiO2 nanoparticles) on the brain, wistar rats were administrated intravenously with various doses of nano-TiO2 (21 nm) through the caudal vein, once a week for 4 weeks and different parameters such as bioaccumulation of nano-TiO2, oxidative stress-mediated response, level of inammatory markers such as NF-jB (p65), HSP 60, p38, nitric oxide, IFN-c and
TNF-a, and level of neurochemicals in brain as well as DNA damage and expression of apoptosis markers (p53, Bax, Bcl-2, and cyto c) were evaluated. Results show that the concentration of nano-TiO2 in the brain increased with increasing the doses of nano-TiO2.
Oxidative stress and injury of the brain occurred as nano-TiO2 appeared to trigger a cascade of reactions such as inammation, lipid peroxidation, decreases the activities of antioxidative enzymes and melatonin level, the reduction of glutamic acid, downregulated
levels of acetylcholinesterase activities, and the increase in caspase-3 activity (a biomarker of apoptosis), DNA fragmentation, and apoptosis. It may be concluded that nano-TiO2 induces oxidative stress that leads to activation of inammatory cytokines and an alteration in the level of neurotransmitters resulted in the induction of mitochondrial-mediated apoptosis.
Keywords TiO2 nanoparticles Oxidative stress
Inammation Apoptosis Nanomedicine Health
effects
Introduction
Nanoparticles (NPs) are the assembled molecules having size less than 100 nm in at least one dimension. In our daily life, NPs are produced by anthropogenic activities such as byproducts of simple combustion (with size down to several nanometers), cooking and more recently, chemical manufacturing, welding, ore rening and smelting, combustion in vehicles and airplane engines, (Rogers et al. 2005), combustion of treated pulverized sewage, sludge (Seames et al. 2002), combustion of coil, and fuels used in power plants (Linak et al. 2000). At the same time,...