E-cigarette aerosol induced cytotoxicity, DNA damages and late apoptosis in dynamically exposed A549 cells.

In this study, the acute toxicological impacts associated with electronic cigarettes consumption were determined using a novel dynamic exposure methodology. The methodology was deployed to test various e-cigarette generated aerosols in A549 cell cultures. The e-liquid chemical profiling was achieved using GC-MS analysis while toxicity of diluted e-liquids aerosols was reported using numerous cytotoxicity assays. The presented findings pointed to acute aerosol exposure (thirty puffs at 40 W of power and higher) inducing significant cytotoxic, genotoxic, and apoptotic induction in exposed cells. These findings highlighted the significant risks posed by e-cigarette usage. The proposed methodology proved to be a useful tool for future screening of e-liquids generated aerosols toxicity. Future research is needed to establish the chronic toxicity resulting from long-term e-cigarette consumption.

Evaluation of waterpipe smoke toxicity in C57BL/6 mice model.

Waterpipe smoking is a popular pastime worldwide with statistics pointing to an alarming increase in consumption. In the current paper, the evaluation of sub-chronic waterpipe smoke exposure was undertaken using C57BL/6 female mice using a dynamic exposure setting to emulate smoke exposure. Mice were daily subjected to either one (single exposure, SE) or two sessions (double exposure, DE) of waterpipe-generated smoke (two-apple flavor) for a period of two months. Although lungs histopathological examination pointed to a minor inflammation in smoke-exposed mice compared to control air-exposed (CON) group, the lung weights of the waterpipe-exposed mice were significantly higher (+72% in SE and +39% in DE) (p < 0.01) when compared to CON group. Moreover, changes in the protein expression of several proteins such as iNOS and JNK were noted in the lungs of smoke-exposed mice. However, no changes in p38 and EGFR protein levels were noted between the three groups of mice. Our results mainly showed a significant increase in urea serum levels (+28%) in SE mice along with renal pathological damage in both SE and DE mice compared to CON. Additionally, severe significant DNA damages (p < 0.05) were reported in the lungs, kidneys, bone marrow and liver of waterpipe-exposed animals, using MTS and COMET assays. These findings highlighted the significant risks posed by sub-chronic waterpipe smoke exposure in the selected animal model and the pressing need for future better management of waterpipe indoor consumption.

Characterization and cytotoxicity assessment of nargile smoke using dynamic exposure.

Objectives: Nargile (waterpipe) smoking has gained popularity in the Middle East and throughout the world. In this research, a new dynamic methodology was conceived. This methodology was deployed for direct in vitro assessment of cytotoxicity, genotoxicity, and apoptotic potential of smoke generated from a single nargile session. Materials and methods: A549 cells were deployed in a designed system to assess the cytotoxicity of generated smoke. The smoke was characterized using Gas chromatography-mass spectrometry (GC-MS) profiling for major organic compounds, whereas the remaining chemical and physical parameters were tabulated from published data. The cytoxicity of smoke generated from five commercial flavored tobacco products was assessed using the (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulphophenyl)-2-H-tetrazolium) (MTS) assay. The genotoxicity was also measured using the comet assay, while apopoptosis was evaluated using Annexin V/propidium iodide staining.Results: The data indicated acute cytotoxicity emanating from smoke products in all tested tobacco flavors. Significant loss of viability and mitochondrial activity was observed 40 min post smoke exposure (Double-Apple flavored), while DNA damage onset was reported as early as 20 min of exposure. Microscopical analysis showed a systematic increase in cell rounding post exposure indicating cellular loss of adhesion and potential membrane damages. Finally, the Annexin V/propidium iodide cellular staining showed signs of late apoptosis or necrosis in exposed cells. Conclusions: The presented data clearly indicated significant in vitro cytotoxicity, genotoxicity and apoptosis/necrosis associated with a 60-min single session of nargile smoking.