title: Vapors produced by electronic cigarettes and e-juices with flavorings induce toxicity, oxidative stress, and inflammatory response in lung epithelial cells and in mouse lung.
abstract: Oxidative stress and inflammatory response are the key events in the pathogenesis of chronic airway diseases. The consumption of electronic cigarettes (e-cigs) with a variety of e-liquids/e-juices is alarmingly increasing without the unrealized potential harmful health effects. We hypothesized that electronic nicotine delivery systems (ENDS)/e-cigs pose health concerns due to oxidative toxicity and inflammatory response in lung cells exposed to their aerosols. The aerosols produced by vaporizing ENDS e-liquids exhibit oxidant reactivity suggesting oxidants or reactive oxygen species (OX/ROS) may be inhaled directly into the lung during a "vaping" session. These OX/ROS are generated through activation of the heating element which is affected by heating element status (new versus used), and occurs during the process of e-liquid vaporization. Unvaporized e-liquids were oxidative in a manner dependent on flavor additives, while flavors containing sweet or fruit flavors were stronger oxidizers than tobacco flavors. In light of OX/ROS generated in ENDS e-liquids and aerosols, the effects of ENDS aerosols on tissues and cells of the lung were measured. Exposure of human airway epithelial cells (H292) in an air-liquid interface to ENDS aerosols from a popular device resulted in increased secretion of inflammatory cytokines, such as IL-6 and IL-8. Furthermore, human lung fibroblasts exhibited stress and morphological change in response to treatment with ENDS/e-liquids. These cells also secrete increased IL-8 in response to a cinnamon flavored e-liquid and are susceptible to loss of cell viability by ENDS e-liquids. Finally, exposure of wild type C57BL/6J mice to aerosols produced from a popular e-cig increase pro-inflammatory cytokines and diminished lung glutathione levels which are critical in maintaining cellular redox balance. Thus, exposure to e-cig aerosols/juices incurs measurable oxidative and inflammatory responses in lung cells and tissues that could lead to unrealized health consequences.
authors: Department of Environmental Medicine, University of Rochester Medical Center, Rochester, NY, United States of America.
authors: Chad A
authors: CA
authors: Lerner
authors: Department of Environmental Medicine, University of Rochester Medical Center, Rochester, NY, United States of America.
authors: Isaac K
authors: IK
authors: Sundar
authors: Department of Environmental Medicine, University of Rochester Medical Center, Rochester, NY, United States of America.
authors: Hongwei
authors: H
authors: Yao
authors: Department of Environmental Medicine, University of Rochester Medical Center, Rochester, NY, United States of America.
authors: Janice
authors: J
authors: Gerloff
authors: Department of Public Health Sciences, University of Rochester Medical Center, Rochester, NY, United States of America.
authors: Deborah J
authors: DJ
authors: Ossip
authors: Department of Public Health Sciences, University of Rochester Medical Center, Rochester, NY, United States of America.
authors: Scott
authors: S
authors: McIntosh
authors: Mechanical Engineering Department, Rochester Institute of Technology, Rochester, NY, United States of America.
authors: Risa
authors: R
authors: Robinson
authors: Department of Environmental Medicine, University of Rochester Medical Center, Rochester, NY, United States of America.
authors: Irfan
authors: I
authors: Rahman
mesh_terms: D000336:Aerosols / Q000009:adverse effects; D000818:Animals; D018893:Bronchoalveolar Lavage; D002460:Cell Line; D003367:Cotinine / Q000097:blood; D066300:Electronic Nicotine Delivery Systems / Q000009:adverse effects*; D005434:Flow Cytometry; D006801:Humans; D051379:Mice; D009538:Nicotine / Q000008:administration & dosage / Q000633:toxicity*; D018384:Oxidative Stress / Q000187:drug effects*; D011014:Pneumonia / Q000139:chemically induced*; D020545:Respiratory Mucosa / Q000187:drug effects*; D012996:Solutions / Q000008:administration & dosage / Q000633:toxicity; D014835:Volatilization
chemical_list: D000336:Aerosols; D012996:Solutions; D009538:Nicotine; D003367:Cotinine