Effects of E-Cigarette Flavoring Chemicals on Human Macrophages and Bronchial Epithelial Cells

Details

• Personal Author:
  Attfield, Kathleen ; Fowles J ; Leonard, Stephanie ; Morris A ; Olgun, Nicole S.
• Description:
  E-cigarettes are a relatively new and popular alternative to tobacco cigarettes used by many young adults and teens. Due to their novelty, the respiratory health effects of e-cigarette flavoring components are not well understood. There are thousands of e-cigarette flavors available on the market, many of which have the potential for toxicity. The majority of e-cigarette flavoring chemicals (ECFCs) have not been tested for inhalation safety. In this study, we used pulmonary-associated cell lines to assess the in vitro effects of thirty ECFCs to determine their potential cytotoxicity at various concentrations. The ECFC vehicles, propylene glycol (PG) and vegetable glycerin (VG), were tested individually and as mixtures that mirrored common ratios found in e-liquids (50/50 and 30/70 PG/VG, respectively). Cultured human monocytes (THP-1) were differentiated into a macrophage phenotype with vitamin D3 before treatment. Cultured human bronchial epithelial cells (BEAS-2B) and differentiated macrophages were treated with 10, 100, and 1000 microM of ECFC and analyzed for cytotoxicity and inflammatory markers, including changes in viability, cell membrane damage, reactive oxygen species (ROS) production, and inflammatory cytokine release. The ECFCs that caused the most cell death in both cell types (eugenol, linalool, and nonanol) were primarily classified as hydroxyls. A number of aldehydes (cinnamaldehyde, decanal, and trans-2-hexen-1-al) also caused significant cell death. Cell membrane damage, as measured by lactate dehydrogenase release, was elevated in both cell lines after treatment with eugenol, linalool, and nonanol. Decanal also caused membrane damage to BEAS-2B cells, while vanillin was damaging to THP-1 cells. Vanillin elicited high amounts of ROS from both cell lines, with the BEAS-2B also producing ROS after exposure to diketones (2,3-pentanedione, 2,3-heptanedione, and 2,3-hexanedione). These findings provide insight into the potential tissue damage that e-cigarette users are at risk for and provide a basis for future experiments with ECFC exposures. [Description provided by NIOSH]
• Subjects:
  Cytotoxins Electrical Equipment And Supplies Flavoring Agents Occupational Health Respiratory System Safety Smokers
• Keywords:
  Cellular Effects Cytokines Cytotoxicity Electronic Devices Flavorings Inhalation Reactive Oxygen Species ROS Smoking
• ISSN:
  1096-6080
• Document Type:
  Text
• Genre:
  Abstract or Summary
• Place as Subject:
  California ; Maryland ; OSHA Region 3 ; OSHA Region 9 ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  HELD - Health Effects Laboratory Division
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  168
• Issue:
  1
• NIOSHTIC Number:
  nn:20054944
• Citation:
  Toxicologist 2019 Mar; 168(1):219
• Federal Fiscal Year:
  2019
• NORA Priority Area:
  Manufacturing
• Peer Reviewed:
  False
• Source Full Name:
  The Toxicologist. Society of Toxicology 58th Annual Meeting and ToxExpo, March 10-14, 2019, Baltimore, Maryland
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:abf6b3cea8fb2fdf9e2ded8234a985014224aa5acf133c4957072f76c699b11b72b8bc30c7a3726dc45989a9bffa6976b2c755181a4fb444b520a157adb5ab8e
• Download URL:
  https://stacks.cdc.gov/view/cdc/217350/cdc_217350_DS1.pdf
• File Type:
  [PDF - 859.30 KB ]