In vitro cytoxicity profile of e-cigarette liquid samples on primary human bronchial epithelial cells
Abstract
Cigarette smoke is associated to severe chronic diseases. The most harmful components of cigarette smoke derive from the combustion process, which are significantly reduced in the electronic cigarette aerosol, thus providing a valid option in harm reduction strategies. To develop safer products, it is therefore necessary to screen electronic cigarette liquids (e-liquids) to meet high safety standards defined by government regulations. The aim of the present study was to evaluate the presence of metal- and plastic-derived contaminants in four different commercial e-liquids with high concentration of nicotine and their cytotoxic effect in normal human bronchial epithelial cells by a number of in vitro assays, in comparison with the 1R6F reference cigarette, using an air-liquid interface (ALI) exposure system. Moreover, we evaluated the effect of aerosol exposure on oxidative stress by measuring the production of reactive oxygen species and mitochondrial potential. Our results showed no contaminants in all e-liquids and a significantly reduced cytotoxic effect of e-liquid aerosol compared to cigarette smoke as well as a maintained mitochondria integrity. Moreover, no production of reactive oxygen species was detected with e-cigarette aerosol. In conclusion, these results support the reduced toxicity potential of e-cigs compared to tobacco cigarettes in an in vitro model resembling real life smoke exposure. ; This study has been supported by ECLAT S.r.l., a research-based spin-off company from the University of Catania that delivers solutions to global health problems with special emphasis on harm minimization and technological innovation. Products have been provided for free by Dreamods S.r.l. The contents, selection, and presentation of facts, as well as any opinions expressed herein, are the sole responsibility of the authors and under no circumstances shall be regarded as reflecting the positions of Dreamods S.r.l.
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