Genotoxicity evaluation of titanium dioxide nanoparticles using the mouse lymphoma assay and the Ames test

Publication date: Available online 1 December 2018Source: Mutation Research/Genetic Toxicology and Environmental MutagenesisAuthor(s): Xiuming Du, Shunxiang Gao, Liling Hong, Xin Zheng, Qingyun Zhou, Jihong WuAbstractTitanium dioxide nanoparticles (TiO2-NPs) are widely used in the cosmetics, health, and food industries, but their safety and genotoxicity remain a matter of debate. We investigated whether TiO2-NPs could induce gene mutations in mouse lymphoma L5178Y cells and Salmonella typhimurium strains TA97a, TA98, TA100, TA102, and TA1535. Following preliminary tests, 2 mg/mL for the mouse lymphoma gene mutation assay and 1.25 mg/plate for the in vitro bacterial reverse mutation assay (Ames test) were selected as the highest concentrations. Exposure to TiO2-NPs for 4 or 24 h with or without S9 metabolic activation did not increase mutation frequency for any of the concentrations tested in L5178Y cells. In the Ames test, TiO2-NPs did not induce reverse mutation in the bacterial strains. No positive mutagenic responses were observed in either test system, and therefore we cannot classify TiO2-NPs as mutagenic; further testing will be required to determine conclusively whether TiO2-NPs are genotoxic.
Source: Mutation Research Genetic Toxicology and Environmental Mutagenesis - Category: Genetics & Stem Cells Source Type: research