E171-induced toxicity in human iPSC-derived colon organoids: Effects on cell viability, ROS generation, DNA damage,
Nicolaj S Bischoff1, Anna K Undas2, Marcel van Herwijnen1
1Department of Translational Genomics, GROW Research Institute for Oncology and Reproduction, Maastricht University Medical Centre, 6229 ER Maastricht, the Netherlands.
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Food-grade titanium dioxide (E171) is a widely used food additive with debated safety, particularly regarding its genotoxic effects. This study assessed the dose-dependent toxicity of E171 in human induced pluripotent stem cell (iPSC)-derived colon organoids. Organoids were exposed to E171 (0.1-1000 μg/mL) for 24 h, and effects on cell viability, reactive oxygen species (ROS) generation, DNA damage, and gene expression were evaluated. Results showed no impact on cell viability but a dose-dependent increase in ROS formation, peaking at 1000 μg/mL. Electrospin Resonance Spectroscopy (ESR) showed a dose-dependent increase in ROS, with increased E171 concentrations. The alkaline comet assay revealed significant DNA damage from 100 μg/mL, with oxidative DNA damage detected at 10 μg/mL using formamidopyrimidine DNA glycosylase (FPG). RNA sequencing identified differentially expressed genes (DEGs) at 100 and 250 μg/mL, linked to translational activity, signal transduction, and DNA damage repair. Gene set enrichment analysis (GSEA) indicated activation of ribosome, chemical carcinogenesis-ROS, and metabolic pathways (carbon metabolism, glycolysis), while key regulatory pathways (Wnt, MAPK, PI3K-Akt) were suppressed. These findings suggest that E171 induces oxidative stress and DNA damage, modulating transcriptomic pathways associated with metabolism, proliferation, and cancer. Further research is necessary to determine its long-term effects on human gastrointestinal health.
