Pod-based menthol and tobacco flavored e-cigarettes cause mitochondrial dysfunction in lung epithelial cells

Current FDA regulations have resulted in a ban of flavored e-cigarette pods, with only menthol and tobacco flavored pods being exempted. Previous work using menthol and tobacco-flavored e-cigarettes have been shown to induce mitochondrial reactive oxygen species. We hypothesized that exposure to pod-based JUUL Menthol and Virginia Tobacco aerosols will alter mitochondrial respiration and electron transport chain protein levels. We determined mitochondrial respiration by using a Seahorse technique and electron transport chain complexes by total OXPHOS antibodies after exposing lung epithelial cells, Beas-2b, to pod-based Menthol and Virginia Tobacco flavored aerosols. Menthol pod exposure resulted in an immediate increase in proton leak and decrease in coupling efficiency, as well as a decrease in complex I, II, and IV. Menthol pod exposure twenty-four hour post-exposure resulted in a decrease in basal respiration, maximal respiration, and spare capacity, as well as a decrease in complex I. Tobacco pod exposure resulted in no significant alterations to mitochondrial respiration, but immediately post final exposure resulted in a significant increase in complex I, IV, and V. Our results indicate that exposure to Menthol flavored e-cigarette pods cause mitochondrial dysfunction in lung epithelial cells.