E-Cigarette Flavoring Agent May Impair Airway Defense System
(HealthDay News) — Cinnamaldehyde, a commonly used flavoring agent in electronic cigarettes (e-cigarettes), disrupts mitochondrial function, correlating with impaired cilia beat frequency (CBF), according to a study presented at the American Thoracic Society's 2018 International Conference, held from May 18 to 23 in San Diego.
Phillip Clapp, Ph.D., from the University of North Carolina at Chapel Hill, and colleagues exposed well-differentiated human bronchial epithelial cell (HBEC) cultures to diluted cinnamon e-liquids and e-liquid aerosol generated by a third-generation e-cigarette device. Using a high-speed digital camera and the Sisson Ammons Video Analysis system, CBF was quantified over 120 minutes. HBECs were exposed to various concentration of cinnamaldehyde to establish a dose-response relationship for CBF alteration.
The researchers found that cinnamaldehyde-containing e-liquid and e-liquid aerosol rapidly suppressed CBF, which lasted for about 60 minutes. The transient ciliostasis that was seen with exposure to e-liquid was recapitulated by exposure to cinnamaldehyde alone. There was impairment of mitochondrial oxidative phosphorylation in a dose-response manner with cinnamaldehyde; following exposure, intracellular adenosine triphosphate levels were reduced significantly. Cells exposed to cinnamaldehyde had cinnamaldehyde adducts with redox and energy metabolism proteins.
"Our finding that cinnamaldehyde impairs normal airway cilia motility is significant because it demonstrates that a common, food-safe flavoring agent, in the context of e-cigarette use, is capable of dysregulating a critical anti-bacterial defense system in the lungs," Clapp said in a statement.