Han-Na Nam

Amorphous silicon dioxide (silica, SiO2) is widely used as an anti-caking agent in products such as chocolate and powdered foods. Although SiO2 is generally considered safe at standard usage levels, concerns regarding its safety persist because research suggests that it may induce inflammation, intestinal dysfunction, and neurotoxicity at the cellular level. In this study, the potential cytotoxicity and genotoxicity of SiO2 as a food additive anti-caking agent were investigated in an intestinal epithelial cell line at practical intake levels, with a focus on differences based on the manufacturing method (fumed and precipitated). The results showed that neither type of SiO2 induces cytotoxicity in terms of cell growth inhibition, cell death via membrane damage, or reactive oxygen species generation. Furthermore, neither type of SiO2 caused DNA damage, chromosomal aberrations, or micronucleus formation. These findings provide fundamental evidence that supports the safety of SiO2 as an anti-caking food additive.

Titanium dioxide (TiO₂), widely recognized as a whitening food additive, has been extensively employed in food products such as confectionery, sauces, and coffee creamers. The potential genotoxicity of TiO₂ has recently raised increasing concern, especially after the European Union prohibited its use as a food additive due to genotoxicity risks. The contradictory outcomes of in vitro and in vivo studies emphasize the necessity for more rigorous and systematic evaluation. In this study, we assessed the potential genotoxicity of food-grade TiO₂ in human intestinal cell lines and intestinal barrier models. Three distinct genotoxicity assays were conducted: the comet assay (DNA tail formation), chromosomal aberration analysis, and the micronucleus assay. The results revealed that TiO₂ exposure led to DNA damage primarily associated with oxidative stress in various intestinal cell systems at actual intake levels, regardless of metabolic activation; however, it did not trigger chromosomal aberrations or micronucleus formation. Thus, TiO₂ appears to cause in vitro genotoxic damage at the DNA level, but not at macroscopic endpoints, such as chromosomal aberrations or micronucleus formation. Further in-depth in vivo study is required to definitively determine the potential genotoxicity of TiO₂ in the food industry.

Terminalia bellirica, a deciduous tree belonging to the family Combretaceae, is a traditional medicinal plant widely used in Southeast Asia. However, information on the bioactivity and safety of T. bellirica is limited. This study aimed to investigate the physiological activities of T. bellirica extract, focusing on its in vitro antioxidant properties. We evaluated the cytotoxic and genotoxic potentials of these compounds. The results revealed that the T. bellirica extract contained high levels of polyphenolic compounds, including tannic acid. In vitro and cell-based analyses confirmed the antioxidant activity and reactive oxygen species-scavenging ability of the extract, suggesting its potential as a functional agent. Furthermore, the extract did not exhibit cytotoxicity or genotoxicity at actual intake levels, as assessed using water-soluble tetrazolium-1 and comet assays. These findings suggest that T. bellirica extract can be safely used as a functional antioxidant.