Evidence map›Paper›PMID 42587134›Full record

ArticleArchives of toxicology2026

Toxic in vitro effects of flavoured-air inhalers containing essential oils in differentiated human nasal epithelial cells at air-liquid interface.

Alexander N Larcombe, E E Catchpole, P Hopper, S Stanley, A Kicic, K R Landwehr, CONQUER

Abstract read
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Article in Archives of toxicology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

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.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

7 authors.

Alexander N LarcombeOccupation, Environment and Safety, School of Population Health, Curtin University, GPO Box U1987, Perth, WA, 6845, Australia. alexander.larcombe@curtin.edu.au.
E E CatchpoleWal-yan Respiratory Research Centre, The Kids Research Institute Australia, Nedlands, Australia.
P HopperWA Organic and Isotope Geochemistry Centre, School of Earth and Planetary Sciences, Faculty of Science and Engineering, Curtin University, Bentley, WA, Australia.
S StanleyWA Organic and Isotope Geochemistry Centre, School of Earth and Planetary Sciences, Faculty of Science and Engineering, Curtin University, Bentley, WA, Australia.
A KicicWal-yan Respiratory Research Centre, The Kids Research Institute Australia, Nedlands, Australia.
K R LandwehrOccupation, Environment and Safety, School of Population Health, Curtin University, GPO Box U1987, Perth, WA, 6845, Australia.
CONQUER

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Flavoured-air inhalers containing essential oils are marketed as safe, natural alternatives to smoking and vaping, yet their potential respiratory toxicity remains effectively unexamined. Manufacturers claim safety based on "100% natural" ingredients, despite evidence that essential oil inhalation can cause adverse respiratory effects. Our objective was to assess the in vitro toxicity of six commercially available flavoured-air products on human nasal airway epithelial cells. Differentiated air-liquid interface cultures of primary nasal airway epithelial cells from eight healthy adults were exposed for one hour to air (control) or flavoured air from three devices (Füm, Lio, Cigtrus; two flavours each) generated by drawing air through essential oil-infused cores at a continuous airflow of 1 L/min for one hour into an 1000 mL exposure chamber. Outcomes included transepithelial electrical resistance, cytotoxicity, protein release, cytokine/chemokine profiling and histological assessment. Chemical analysis characterised the chemical composition of device cores and identified 29 compounds across the six products, including the possible carcinogen pulegone and cytotoxic cinnamaldehyde. Five of six flavours significantly reduced transepithelial electrical resistance indicating compromised epithelial barrier integrity. Mediator responses were compartment-specific: apical surfaces showed predominantly pro-inflammatory profiles while basal release was broadly suppressed. Histological analysis revealed reduced cilia coverage, fewer mucus-producing cells, and decreased epithelial thickness across multiple treatments. This study shows that a single one-hour exposure to flavoured-air vapour led to epithelial barrier dysfunction, immune dysregulation, and structural damage in healthy human nasal airway epithelial cells, contradicting manufacturer safety claims. Rigorous toxicological evaluation of these products is urgently needed.

Indexed as

Air–liquid interfaceAirway epithelial cellsEssential oilsFlavoured-airRespiratory toxicity

Identifiers

PMID42587134

What OpenQuestion holds

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Read underepoch 390

Registered trials

None linked

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.