Discipline: Biological Sciences
Shanaliz Natta - University of the Virgin Islands
Co-Author(s): Phillip Clapp, University of North Carolina at Chapel Hill, Chapel Hill, NC; Dr. Ilona Jaspers, University of North Carolina at Chapel Hill, Chapel Hill, NC
Electronic cigarettes have gained popularity, particularly with young adults who perceive these products as a safe alternative to smoking. However, recent studies have demonstrated that some flavored e-liquids contain high concentrations of reactive flavoring agents which have not been evaluated for inhalation toxicity. Some flavoring compounds activate Nrf2, a master regulator of antioxidant responses, in cells lining the GI tract and in the liver, but whether inhalation of flavoring agents stimulates lung antioxidant responses is unclear. Here we investigate whether flavoring agents commonly used in e-liquid formulations activate the Nrf2 antioxidant pathway in airway epithelial cells. An e-liquid toxicity database was used to identify common flavoring agents in the top 50 most cytotoxic e-liquids. Eight of the most common flavoring agents (cinnamaldehyde, guaiacol, eugenol, isoamyl acetate, limonene, linalool, menthol, and benzaldehyde) were purchased and used to challenge Beas-2B cells, a human bronchial epithelial cell line, over a range of concentrations (10nM to 10mM). Cells were exposed for 24 hours and dose-dependent effects on viability and Nrf2 antioxidant pathway activation were assessed. All of the compounds tested caused significant cell death at the 10mM concentration except for guaiacol, benzaldehyde, and isoamyl acetate, which were not cytotoxic at any of the doses tested. Cinnamaldehyde (0.001mM and 0.01mM), guaiacol (0.1mM and 1mM), and eugenol (0.1mM) significantly activated the Nrf2 pathway as compared to the media only control. These data indicate that some common e-cigarette flavoring agents activate Nrf2 in lung epithelial cells at relevant concentrations; however, further work is needed to elucidate the mechanism of Nrf2 pathway activation.Not Submitted
Funder Acknowledgement(s): TCORS P50 HL120100 SOT Summer Undergraduate Internship NIH MARC Trainee Program Award #5T34GM008422
Faculty Advisor: Ilona Jaspers, Ph.D, email@example.com
Role: This research was done by myself. I was heavily involved in the processes such as cell culture, assays, data collection, and literature work.