March 7, 2017

Misleading E-Cigarette Headlines

Headlines in Nature journal implicate e-cigarettes in a study on nicotine impacts and cultured smooth muscle-like cells, and many readers are being misled.

A new scientific article [1] hit the pages of Nature with some rather alarming information about e- cigarettes. This frightening title read: “Myofibroblast differentiation and its functional properties are inhibited by nicotine and e-cigarette via mitochondrial OXPHOS complex III“. The findings of this research were funded by a grant from China, revealing that nicotine inhibited myofibroblast differentiation. It also found that the impact of nicotine and e-cigarettes were similar.

Something is not right…

This study should raise a few eyebrows here and there. The physiological process written about, that of cellular transformation into myofibroblasts, is one which enables tissue repair and promotes fibrosis. The impact of nicotine in this area is not new and was written about in 2005 when researchers looked at the inhibition of myofibroblast differentiation [2] and found that smokers who ingested nicotine did not heal from regular wounds as quickly as nonsmokers. This study was actually a reproduction of an older study [3]. Chilean researchers found that cigarette smoke could stimulate cell survival depending on the levels of nicotine [4]. Wei Lei, Isaac K. Sundar, Irfan Rahman and Chad Lerner, who authored the current study out of the University of Rochester Medical Center (Rochester, NY, USA) bought nicotine e-liquid and used dry ice as the condensate.

What is surprising is that concerns were raised about e-cigarette nicotine when nicotine comes from so many sources beyond e-cigarettes. It comes from hookahs, snus, nicotine sprays, cigars, and of course, cigarettes. This work is intentionally misleading by failing to mention the myriad other sources from which nicotine could be derived. At the very least, the work should have mentioned this in the end of their publication, where normal scientists and researchers state limitations of the study and where future researchers could take the study one step further. It would have been better for these authors to clearly state at the end of their work that they did not compare the nicotine from the other aforementioned sources, but a future study could stand to compare all of them for the sake of determining which method of nicotine is the safest.

The authors stated that they used an unbiased approach to their work and held themselves to rigorous standards. Yet, there is not a single reference in their work to the type of e-liquid used for the experiments. This should have been stated in the very beginning, in the abstract and then again in the methodology. More importantly, they did not mention the final concentrations of CO2 or nicotine used in the medium inside of which cells were soaked. Their paper lacked any mention of relative concentrations of VG or PG within the e-liquids. Unfortunately, these are not the only sins committed.

The paper protocol does not take into account that previous research showed an eGo battery like the one they used, was able to burn e-liquid in dry puffs and release excess amounts of formaldehyde and acrolein when used with a vaping machine. Clearly, their literature review was incomplete. As was their methodology.

So many questions left unanswered

Now, one must ask how e-cigarette condensate at 0.1% or 0.25% really compare with the 100 μM or 1 mM Sigma nicotine. One must ask how much carbon dioxide from e-cigarette condensate at 0.1% or 0.25% compared to the 5% concentrate added to the medium. Finally, one must ask how impacted the pH of the medium is and whether that medium is viable for cultured cells.

Nature actually stated that in order for any work to be considered for publication, it “must be technically sound original research, without any requirement for impact or a conceptual advance.” This particular article raises questions about that, and clearly does not meet with the “strict” editorial requirements. If this study truly conformed to the “NIH standards of reproducibility and scientific rigor”, as testified by the authors, then it stands to reason that in the future, NIH studies might better serve their readers if they are held to a second round of rigor from within the international community. It should be a surprise that this level of poor work was not caught during the editorial process and removed before it was published.

Now it seems that the only solution is to demand better editorial standards, encourage another round of editing from within the community, and force scientific publications like this one to raise their standards to what was once a widely accepted level of science.

[1] Lei, W., Lerner, C., Sundar, I. K., & Rahman, I. (2017). Myofibroblast differentiation and its functional properties are inhibited by nicotine and e-cigarette via mitochondrial OXPHOS complex III. Scientific Reports, 7, 43213.

[2] Fang, Y., & Svoboda, K. K. (2005). Nicotine inhibits myofibroblast differentiation in human gingival fibroblasts. Journal of cellular biochemistry, 95(6), 1108-1119.

[3] Campanile, G., Hautmann, G., & Lotti, T. (1998). Cigarette smoking, wound healing, and face-lift. Clinics in dermatology, 16(5), 575-578.

[4] Silva, D., Cáceres, M., Arancibia, R., Martínez, C., Martínez, J., & Smith, P. C. (2012). Effects of cigarette smoke and nicotine on cell viability, migration and myofibroblastic differentiation. Journal of periodontal research, 47(5), 599-607.

Back Work With Us