03 October 2016
Oxidative stress and cell death are driving factors in the development of many smoking-related diseases such as COPD and lung cancer. Recent tests conducted by scientists at British American Tobacco (BAT) show that, in stark contrast to cigarette smoke, vapour from the commercially available e-cigarette Vype ePen is less toxic to, and does not cause oxidative stress¹ in, human lung cells.
In one study, human lung airway tissue was separately exposed to Vype vapour and smoke from a reference cigarette in a way that mimicked real-life exposure. The cytotoxic effect on the cells was then measured using a well-established assay. Cigarette smoke was found to be cytotoxic even at exposure levels typical in real life. Vype vapour, however, was less toxic under normal usage conditions. In fact, in order to elicit a cytotoxic response at all it was necessary to deliver an estimated daily dose of vapour in only an hour. Even at this extreme dose—equivalent to 10 times higher than from the cigarette—the Vype vapour was found to be significantly less toxic than cigarette smoke.
‘The conservative approach we took means that it is extremely unlikely that normal vaping use with the Vype ePen would yield cytotoxic effects,” says Dr Chris Proctor, BAT’s Chief Scientific Officer.
In another experiment, lung epithelial cells were exposed to the same concentrations of either smoke or vapour extract and then a panel of commercially available assays was used to measure and compare the stress responses of the cells. Cells exposed to the concentrations of cigarette smoke showed signs of oxidative stress and, at higher doses, cytotoxicity². The e-cigarette vapour, however, had no such effects, even at the highest concentration.
‘Results from these tests highlight the scale of difference in potency between e-cigarette vapour and cigarette smoke and adds to the weight of evidence on the reduced risk potential of e-cigarettes,” says Dr Chris Proctor.
The tests are part of a suite of experiments being developed by BAT to assess novel tobacco and nicotine products.
Compared to cigarette smoke, e-cigarette vapour contains similar levels of nicotine but very low levels of potentially harmful chemicals. Suitable lab tests and clinical studies are necessary to understand whether this translates into reductions in biological response and disease.
1. Taylor M, Carr T, Oke O, Jaunky T, Breheny D, Lowe F, Gaca M (2016). E-cigarettes aerosols induce lower oxidative stress in vitro when compared to tobacco smoke. Toxicology Mechanisms and Methods, 26, 6.
2. Azzopardi D, Patel K, Jaunky T, Santopietro S, Camacho O, McAughey J, Gaca M (2016). Electronic cigarettes aerosol induces significantly less cytotoxicity than tobacco smoke. Toxicology Mechanisms and Methods, 26, 6.
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