| Human bronchial epithelial cells (H292) |
Strawberry Tobacco Pina colada Menthol Coffee |
3 s puff duration, every 30s, with a 55 mL puff volume. A period of 30 min was used as this was the minimum exposure at ALI. |
0, 6, 12, 18, or 24 mg/mL of nicotine |
Nicotine alone control present. |
Strawberry flavor was most cytotoxic following neutral red assay. Exposure to each aerosol decreased metabolic activity and cell viability. Coffee increased the release of IL-6, CXCL1, and CXCL2. Strawberry increased the release of IL-1ß IL-10, CYCL1, CXCL2, and CXCL10. No significant differences were observed between the different concentrations of nicotine and air control for both metabolic activity and viability. Unflavored e-liquids significantly decreased in IL-1β, CXCL1, and CXCL2 in response to 18 mg/mL nicotine aerosol versus air controls. Unflavored e-liquids significantly increased IL-6 in response to 24 mg/mL nicotine aerosol versus air control.
|
(Leigh et al. 2016) |
| Primary bronchial epithelial cells and human distal lung epithelial cells (NCI-H441) |
|
40 ml/puff, 3s puff duration, 30s puff interval, 10 puffs/ session at ALI |
0, 3 mg/ml |
No nicotine alone control present |
Exposure to mix-1 (nicotine-free) significantly increased transcript expression of pro-inflammatory cytokines CXCL8, IL6, NFKB1, TNF (not specified whether α or β
Mix-2 (nicotine-free) PI3 transcript was reduced two-fold. The presence of nicotine in mix-1 significantly reduced the release of inflammatory markers of IL-1ß, 1 L-10, IL-13, and IL-6.
The presence of nicotine in mix-2 increased the transcript of TNF (not specified whether α or β) |
(Ganguly et al. 2020) |
| H292 cells |
|
|
|
No nicotine control |
1 Day of exposure is cytotoxic, alters gene expression, and increases reactive oxygen species (cinnamon> butter). After 3 days of exposure, cinnamon flavor is more cytotoxic following LDH assay and causes oxidative damage to a greater extent
than butter-flavored e‑cig aerosol.
|
(Noël et al. 2020b) |
A549 (3D) co-culture of alveolar
and H441 cells |
|
24-h exposure to condensed aerosol (puff regime was set to 55 mL puff volume, 3 s draw, 60s 200 puff) |
0 mg/ mL & 18 mg/ mL |
No Nicotine control present |
Cell viability significantly decreased in mono- and 3D culture by mint and cinnamon. Significant IL-8 release only in monoculture after Cinnamon exposure. No increase in MCP-1 release
|
(Bengalli et al. 2017) |
| CALU-3 airway epithelial cells |
|
24-h direct e-liquid exposure (0%, 0.1%, 0.3%, 1%, 3.0%, 6.0%, 10% (v/v)) |
0 mg/mL and 12 mg/mL of nicotine |
Nicotine alone control present |
Hot cinnamon candies and menthol tobacco show cytotoxicity (cell and mitochondria viability) in the absence of nicotine. Nicotine control decreases cell proliferation and viability dose-dependently and is cytotoxic compared to the PG/VG controls. Nicotine (12 mg/mL) containing captain black cigar e-liquid showed more cytotoxicity (MTT assay) compared to captain black cigar alone. Nicotine-free e-liquids inhibit cell proliferation and viability in a dose-dependent manner.
|
(Rowell et al. 2017) |
| Human adenocarcinoma alveolar basal epithelial cells (A549 cells) |
|
50 min aerosol exposure followed by analysis at 2-h, 6-h, 24-h. |
Nicotine concentration not specified |
No nicotine alone control present |
Nicotine-free balsamic aerosol caused a significant, progressive, time-dependent loss of viability and increased cytotoxicity following LDH assay. Nicotine-contained e-liquids compared to flavor alone caused a significant loss in viability and enhanced LDH release. Quantitative and qualitative responses are superimposable to that of cigarette smoke exposure. Humectants alone did not cause cytotoxicity even 24 hours after treatment. |
(Cervellati et al., 2014) |
| Human airway epithelial cells (H292) AND human lung fibroblast cells (HFL-1) |
Tobacco Cinnamon roll Grape |
30 s interval with a 4 s pulse for different time durations 5, 10, and 15 minutes |
0, 6, 16, 18 and 24 mg |
No nicotine alone control present |
Nicotine-free tobacco and cinnamon roll-flavored e-liquid increased the secretion of inflammatory cytokines IL-6 and IL-8 in H292 and HFL-1. Nicotine-contained tobacco flavored e-liquid had a significant increase in IL-8 secretion in a dose-dependent manner in HFL-1 but not on other markers. |
(Lerner et al., 2015) |
| Human adenocarcinoma alveolar basal epithelial cells (A549) |
|
Six puffs were dissolved per 1 mL of A549 culture medium, referred to as 6 total-puff- equivalents (TPE) of aerosol, and grown in control or treatment medium for 3–8 days. |
48 mg/ml
(No nicotine free e-liquids present) |
No nicotine control |
Both EC liquids and aerosols induced epithelial-to-mesenchymal transition (EMT) Both tobacco and Menthol flavors alter cell-to-cell junctions induced an EMT, internalization of E-cadherin, increased motility, and upregulation of EMT markers. The EMT was concurrent with the plasma membrane to nuclear translocation of active β-catenin. Due to the lack of nicotine controls, it is unclear whether the effects observed are a result of an interaction between flavor and nicotine or as a flavor effect. No cytotoxicity was measured. |
(Zahedi et al. 2018) |
| Primary human epithelial cells (HBEC), cancerous human bronchial epithelial cells CALU-3 |
|
5–25 puffs |
0 and 12 mg/ml nicotine |
No nicotine alone control, but 0 mg/mL BP |
BP acutely elevates cytosolic Ca2+ in both pulmonary cell types in no nicotine samples. No adverse effects induced by PG:VG in HBEC and CALU-3. Nicotine increased ER Ca2+ in CALU-3. Effect of nicotine on HBEC was not characterized. |
(Rowell et al., 2020) |
