The effects of a human food additive, titanium dioxide nanoparticles E171, on Drosophila melanogaster - a 20 generation dietary exposure experiment

Abstract

In this study, fruit flies (Drosophila melanogaster) were exposed to an estimated daily human E171 consumption concentration for 20 generations. Exposure to E171 resulted in: a change in normal developmental and reproductive dynamics, reduced fecundity after repetitive breeding, increased genotoxicity, the appearance of aberrant phenotypes and morphologic changes to the adult fat body. Marks of adaptive evolution and directional selection were also exhibited. The larval stages were at a higher risk of sustaining damage from E171 as they had a slower elimination rate of TiO2 compared to the adults. This is particularly worrisome, since among the human population, children tend to consume higher daily concentrations of E171 than do adults. The genotoxic effect of E171 was statistically higher in each subsequent generation compared to the previous one. Aberrant phenotypes were likely caused by developmental defects induced by E171, and were not mutations, since the phenotypic features were not transferred to any progeny even after 5 generations of consecutive crossbreeding. Therefore, exposure to E171 during the early developmental period carries a higher risk of toxicity. The fact that the daily human consumption concentration of E171 interferes with and influences fruit fly physiological, ontogenetic, genotoxic, and adaptive processes certainly raises safety concerns.

Toxicological effects of ingested nanocellulose in in vitro intestinal epithelium and in vivo rat models

“…Likewise, the modest and significant increases in ROS production, and corresponding small increases in cytotoxicity, observed with MC and TiO 2 exposures suggest that these materials may not be safe. Indeed, in the case of TiO 2 this has been borne out in numerous studies 35,36,[48][49][50][51][52][53][54] , and has led France to announce its intention to ban the use of TiO 2 as a food additive. Finally, when dispersed in a standardized food model rather than phosphate buffer alone, no increase over control in either cytotoxicity or ROS production was observed with CNC-25, suggesting that the effect of a more complex food matrix in this case was to eliminate the slight toxicity observed in the fasting diet.…”

“…[27][28][29][30] Moreover, inorganic ENMs such as TiO 2 , Ag and ZnO have been linked to tumorigenesis, genotoxicity, changes in the gut microbiome and exacerbation of inflammatory diseases such as colitis. [31][32][33][34][35][36] Studies of nanocellulose exposure in various in vitro cell lines and animal models are limited and have found no evidence of significant toxicity [37][38][39] , however these studies have either focused on other routes of exposure (e.g., inhalation), or have ignored the effects of digestion and interactions with the food matrix on the physicochemical properties of ingested NC. Yet understanding and accounting for these transformations are essential to the study of ingested nanomaterials [40][41][42] .…”

Possible Adverse Effects of Food Additive E171 (Titanium Dioxide) Related to Particle Specific Human Toxicity, Including the Immune System

“…Caenorhabditis elegans exposed to E171 showed a concentration-dependent effect on worm reproduction, brood size, and overall display a reduced life span as well as TiO 2 accumulation in their intestine [ 117 ]. E171 exposure to D. melanogaster showed an increase in pupation time, changes in the development of larvae, and altered overall reproductive activity, which was accompanied by gene expression changes of CAT and SOD [ 118 , 119 ].…”

Fluorescent Markers: Proteins and Nanocrystals

“…Titanium dioxide (TiO 2 ) nanocrystals (NCs) have been used in several types of cosmetics, food, and the textile industry. [9,10] This is because this NC has a wide variety of properties that improve materials, such as its bioluminescence and chemical stability. [11] Bioluminescent techniques are widely used in biomedicine for studies of drug screening, molecular markers, and monitoring of molecular reactions, among other applications.…”