ArticleAmerican journal of physiology. Lung cellular and molecular physiology2017
Flavored e-cigarette liquids and cinnamaldehyde impair respiratory innate immune cell function.
Article in American journal of physiology. Lung cellular and molecular physiology, 2017. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 151 papers, 6 of them syntheses that pooled it.
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The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
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Who cites it
151 citing papers in PubMed, 6 syntheses or guidelines pooled it, 231 citations in OpenAlex.
- From immunological mechanisms to targeted therapies: a bibliometric analysis in the domain of research concerning neutrophil extracellular traps and pulmonary diseases (2006-2025).Frontiers in immunology · 2026Pooled it
- The impact of electronic cigarettes on the outcomes of total joint arthroplasty.Archives of orthopaedic and trauma surgery · 2024Pooled it
- Review of quantitative and functional lung imaging evidence of vaping-related lung injury.Frontiers in medicine · 2024Pooled it
- Pulmonary effects of e-liquid flavors: a systematic review.Journal of toxicology and environmental health. Part B, Critical reviews · 2022Pooled it
- Lung Damage Caused by Heated Tobacco Products and Electronic Nicotine Delivery Systems: A Systematic Review.International journal of environmental research and public health · 2021Pooled it
- E-cigarette use and respiratory disorders: an integrative review of converging evidence from epidemiological and laboratory studies.The European respiratory journal · 2021Pooled it
- Impact of E-Liquids on Phagocytosis, Escape and Invasion ofPathogens (Basel, Switzerland) · 2026Article
- Toxic in vitro effects of flavoured-air inhalers containing essential oils in differentiated human nasal epithelial cells at air-liquid interface.Archives of toxicology · 2026Article
- Impact of e-cigarette vaping on the immune system across the body.Physiological reviews · 2026Review
- Vaping-related lung disease: a narrative review.Journal of thoracic disease · 2026Review
- Altered lung function in mice is a sensitive indicator of lung damage following 6 months of electronic nicotine delivery system aerosol exposure.American journal of physiology. Lung cellular and molecular physiology · 2026Article
- Self-reported voice symptoms in e-cigarette users: a cross-sectional study.European archives of oto-rhino-laryngology : official journal of the European Federation of Oto-Rhino-Laryngological Societies (EUFOS) : affiliated with the German Society for Oto-Rhino-Laryngology - Head and Neck Surgery · 2026Article
- Toxicity and Appeal of Flavoured E-Cigarettes and Flavour Ban Outcomes: A Narrative Review.International journal of environmental research and public health · 2026Review
- Oxidative stress mediates cardiac electrophysiological injury in inhalation exposure to flavored vaping products.Heart rhythm · 2026Article
- Aromatic aldehydes formed during heating of cinnamon-flavored e-liquids drive pro-inflammatory responses in human aortic smooth muscle cells.Current research in toxicology · 2026Article
- Partial amelioration of a chronic cigarette-smoke-induced phenotype in mice by switching to electronic cigarettes.Archives of toxicology · 2025Article
- Impact of nicotine-free and nicotine-rich flavored electronic cigarette refill liquids on primary human melanocyte function.Toxicology reports · 2025Article
- Polarization of THP-1-Derived Human M0 to M1 Macrophages Exposed to Flavored E-Liquids.Toxics · 2025Article
- E-Cigarette or Vaping Product Use-Associated Lung Injury: A Comprehensive Review.International journal of environmental research and public health · 2025Review
- Stability of Flavoring Chemicals in e-Cigarette Liquids: A Naturalistic Product Aging Study over 24 months.ACS omega · 2025Article
91 more citing papers are in PubMed but not listed here.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
7 authors at 1 institution in 1 country.
Funding
Abstract
Innate immune cells of the respiratory tract are the first line of defense against pathogenic and environmental insults. Failure of these cells to perform their immune functions leaves the host susceptible to infection and may contribute to impaired resolution of inflammation. While combustible tobacco cigarettes have been shown to suppress respiratory immune cell function, the effects of flavored electronic cigarette liquids (e-liquids) and individual flavoring agents on respiratory immune cell responses are unknown. We investigated the effects of seven flavored nicotine-free e-liquids on primary human alveolar macrophages, neutrophils, and natural killer (NK) cells. Cells were challenged with a range of e-liquid dilutions and assayed for their functional responses to pathogenic stimuli. End points included phagocytic capacity (neutrophils and macrophages), neutrophil extracellular trap formation, proinflammatory cytokine production, and cell-mediated cytotoxic response (NK cells). E-liquids were then analyzed via mass spectrometry to identify individual flavoring components. Three cinnamaldehyde-containing e-liquids exhibited dose-dependent broadly immunosuppressive effects. Quantitative mass spectrometry was used to determine concentrations of cinnamaldehyde in each of the three e-liquids, and cells were subsequently challenged with a range of cinnamaldehyde concentrations. Cinnamaldehyde alone recapitulated the impaired function observed with e-liquid exposures, and cinnamaldehyde-induced suppression of macrophage phagocytosis was reversed by addition of the small-molecule reducing agent 1,4-dithiothreitol. We conclude that cinnamaldehyde has the potential to impair respiratory immune cell function, illustrating an immediate need for further toxicological evaluation of chemical flavoring agents to inform regulation governing their use in e-liquid formulations.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.