title: Identification of nanoscale ingredients in commercial food products and their induction of mitochondrially mediated cytotoxic effects on human mesenchymal stem cells.
abstract: Titanium dioxide (E171) and silicon dioxide (E551) are common additives found in food products, personal-care products, and many other consumer products used in daily life. Recent studies have reported that these food additives (manufactured E171 and E551) contain nanosized particles of less than 100 nm. However, the particle size distribution and morphology of added TiO2 and SiO2 particles are not typically stated on the package label. Furthermore, there is an increasing debate regarding health and safety concerns related to the use of synthetic food additives containing nanosized ingredients in consumer products. In this study, we identified the size and morphology of TiO2 and SiO2 particles in commercially available food products by using transmission electron microscope (TEM). In addition, the in vitro toxicological effects of E171 and E551 on human mesenchymal stem cells (hMSCs), an adult stem cell-based model, were assessed using the MTT assay and a flow cytometry-based JC-1 assay. Our TEM results confirmed the presence of nanoscale ingredients in food products, and the in vitro toxicology results indicated that the nanoscale E171 and E551 ingredients induced dose-dependent cytotoxicity, changes in cellular morphology, and the loss of mitochondrial trans-membrane potential in hMSCs. These preliminary results clearly demonstrated that the nanoscale E171 and E551 particles had adverse effects on hMSCs by inducing oxidative stress-mediated cell death. Accordingly, further studies are needed to identify the specific pathway involved, with an emphasis on differential gene expression in hMSCs.
authors.affiliation: Nanobiotechnology and Molecular Biology Research Lab, Dept. of Food Science and Nutrition, College of Food Science and Agriculture, College of Food Science and Agriculture, King Saud Univ, P.O. Box 2455, Riyadh-11451, Saudi Arabia.
authors.forename: Jegan
authors.initials: J
authors.lastname: Athinarayanan
authors.forename: Ali A
authors.initials: AA
authors.lastname: Alshatwi
authors.forename: Vaiyapuri S
authors.initials: VS
authors.lastname: Periasamy
authors.forename: Abdulrahman A
authors.initials: AA
authors.lastname: Al-Warthan
mesh_terms: D002454:Cell Differentiation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D005503:Food Additives / Q000737:chemistry*; D006801:Humans; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D059630:Mesenchymal Stem Cells / Q000187:drug effects*; D049329:Nanostructures / Q000737:chemistry*; D018384:Oxidative Stress / Q000187:drug effects; D010316:Particle Size; D012822:Silicon Dioxide / Q000737:chemistry; D014025:Titanium / Q000737:chemistry; D018675:Toxicity Tests
chemical_list: D005503:Food Additives; C009495:titanium dioxide; D012822:Silicon Dioxide; D014025:Titanium
keywords: E171; E551; food additives; human mesenchymal stem cells; oxidative stress