Summary
The study by Morris et al. investigated the effects of 30 e-cigarette flavoring chemicals on human bronchial epithelial cells (BEaS-2B) and macrophages (ThP-1). The flavoring chemicals were selected based on their relative frequency of detection in e-cigarette liquids, diversity of chemical structures, lack of inhalation toxicity data, and presence on the Flavor and Extract Manufacturers association of the United States (FEMa) priority lists.
The study found that many of these flavoring chemicals caused significant changes in cell viability, cytotoxicity, and inflammatory responses compared to the vehicle control. Specifically, they found that 23 out of the 30 flavoring chemicals caused significant changes in at least one of the assays in BEaS-2B cells, and 25 out of the 30 flavoring chemicals caused significant changes in at least one of the assays in ThP-1 cells.
additionally, they used machine learning methods such as cluster analysis and random forest algorithms to investigate the predictions of the most important factors in overall assay outcomes based on the relative biological activity and toxicity of the chemicals. They found that some of the buttery flavoring chemicals (diketones) were associated with severe adverse effects, despite being present on the FEMa priority lists.
In summary, the study found that many e-cigarette flavoring chemicals have the potential to cause significant changes in cell viability, cytotoxicity, and inflammatory responses in human bronchial epithelial cells and macrophages. The study highlights the need for further research into the potential health effects of these flavoring chemicals, particularly the diketones, in e-cigarettes.
Citation
Morris aM, Leonard SS, Fowles JR, Boots TE, Mnatsakanova a, attfield KR. Effects of E-Cigarette Flavoring Chemicals on human Macrophages and Bronchial Epithelial Cells. International journal of environmental research and public health. 2021;18(21). doi:10.3390/ijerph182111107
