Summary
This article reports new evidence related to the reduced risk toxicological profile of commercially available flavors across the Vuse ePod vapor platform. The study aimed to determine if different flavored e-liquids have distinct toxicological profiles and assessed a selection of commercially available ePod flavors in a submerged 2D in vitro screening approach using NCI-h292 human bronchial epithelial cells. The tested e-liquids were ranked based on their cytotoxicity profile, and selected flavors were followed up using a physiologically relevant 3D in vitro human lung tissue (Mucilair) as an air-liquid interface aerosol exposure model measuring toxicity and functional endpoints. The toxicological responses to cigarette smoke (1R6F research cigarette) were compared to contextualize vapor aerosol responses.
Key Points:
* The study assessed the contribution of e-liquid flavorings on overall product toxicity compared to the toxicity of a reference cigarette (1R6F) using both monolayer cells with apical exposure of e-liquid diluted into the cell culture media and on multi-layer reconstructed lung tissues with undiluted whole aerosol techniques.
* The relative toxicity of e-liquids tested to its cigarette smoke comparator was assessed using an IC80 (point of departure) and confirmed using benchmark dosing approaches.
* Data were presented as a function of nicotine to align data and give a quantitative measure of dose.
* Vuse ePod e-cigarette device and a range of commercially available flavors at 18 mg/mL nicotine strength were tested.
* E-liquids were prepared using a consistent PG:VG base formulation, and this base formulation was included in the study to show the effect of an 'unflavoured' e-liquid.
* Product technical standards for vaping products should include the safety and quality of ingredients used, battery and device safety, and should be of the highest quality and purity.
* The study demonstrates that the tested flavors do not increase overall toxicity levels in a flavour or concentration-dependent manner compared to cigarette smoke.
Main Message:
The main message of this study is that flavored e-cigarette products, when appropriately stewarded, do not increase the overall measured aerosol toxicity compared to cigarette smoke. The measured in vitro cellular toxicity of flavored e-cigarette products remains significantly reduced (F95%) compared to cigarette smoke toxicity. This suggests that flavored e-cigarette products can potentially play a role in tobacco harm reduction.
Citation
Bishop E, East N, Miazzi F, et al. a contextualised e-cigarette testing strategy shows flavourings do not impact lung toxicity in vitro. Toxicology letters. 2023;380:1-11. doi:10.1016/j.toxlet.2023.03.006
