TY - JOUR
T1 - Effect of flavoring chemicals on free radical formation in electronic cigarette aerosols
AU - Bitzer, Zachary T.
AU - Goel, Reema
AU - Reilly, Samantha M.
AU - Elias, Ryan J.
AU - Silakov, Alexey
AU - Foulds, Jonathan
AU - Muscat, Joshua
AU - Richie, John
N1 - Publisher Copyright:
© 2018 Elsevier Inc.
PY - 2018/5/20
Y1 - 2018/5/20
N2 - Background: Flavoring chemicals, or flavorants, have been used in electronic cigarettes (e-cigarettes) since their inception; however, little is known about their toxicological effects. Free radicals present in e-cigarette aerosols have been shown to induce oxidative stress resulting in damage to proliferation, survival, and inflammation pathways in the cell. Aerosols generated from e-liquid solvents alone contain high levels of free radicals but few studies have looked at how these toxins are modulated by flavorants. Objectives: We investigated the effects of different flavorants on free radical production in e-cigarette aerosols. Methods: Free radicals generated from 49 commercially available e-liquid flavors were captured and analyzed using electron paramagnetic resonance (EPR). The flavorant composition of each e-liquid was analyzed by gas chromatography mass spectroscopy (GCMS). Radical production was correlated with flavorant abundance. Ten compounds were identified and analyzed for their impact on free radical generation. Results: Nearly half of the flavors modulated free radical generation. Flavorants with strong correlations included β-damascone, δ-tetradecalactone, γ-decalactone, citral, dipentene, ethyl maltol, ethyl vanillin, ethyl vanillin PG acetal, linalool, and piperonal. Dipentene, ethyl maltol, citral, linalool, and piperonal promoted radical formation in a concentration-dependent manner. Ethyl vanillin inhibited the radical formation in a concentration dependent manner. Free radical production was closely linked with the capacity to oxidize biologically-relevant lipids. Conclusions: Our results suggest that flavoring agents play an important role in either enhancing or inhibiting the production of free radicals in flavored e-cigarette aerosols. This information is important for developing regulatory strategies aimed at reducing potential harm from e-cigarettes.
AB - Background: Flavoring chemicals, or flavorants, have been used in electronic cigarettes (e-cigarettes) since their inception; however, little is known about their toxicological effects. Free radicals present in e-cigarette aerosols have been shown to induce oxidative stress resulting in damage to proliferation, survival, and inflammation pathways in the cell. Aerosols generated from e-liquid solvents alone contain high levels of free radicals but few studies have looked at how these toxins are modulated by flavorants. Objectives: We investigated the effects of different flavorants on free radical production in e-cigarette aerosols. Methods: Free radicals generated from 49 commercially available e-liquid flavors were captured and analyzed using electron paramagnetic resonance (EPR). The flavorant composition of each e-liquid was analyzed by gas chromatography mass spectroscopy (GCMS). Radical production was correlated with flavorant abundance. Ten compounds were identified and analyzed for their impact on free radical generation. Results: Nearly half of the flavors modulated free radical generation. Flavorants with strong correlations included β-damascone, δ-tetradecalactone, γ-decalactone, citral, dipentene, ethyl maltol, ethyl vanillin, ethyl vanillin PG acetal, linalool, and piperonal. Dipentene, ethyl maltol, citral, linalool, and piperonal promoted radical formation in a concentration-dependent manner. Ethyl vanillin inhibited the radical formation in a concentration dependent manner. Free radical production was closely linked with the capacity to oxidize biologically-relevant lipids. Conclusions: Our results suggest that flavoring agents play an important role in either enhancing or inhibiting the production of free radicals in flavored e-cigarette aerosols. This information is important for developing regulatory strategies aimed at reducing potential harm from e-cigarettes.
UR - http://www.scopus.com/inward/record.url?scp=85044170146&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85044170146&partnerID=8YFLogxK
U2 - 10.1016/j.freeradbiomed.2018.03.020
DO - 10.1016/j.freeradbiomed.2018.03.020
M3 - Article
C2 - 29548792
AN - SCOPUS:85044170146
SN - 0891-5849
VL - 120
SP - 72
EP - 79
JO - Free Radical Biology and Medicine
JF - Free Radical Biology and Medicine
ER -