Key Points
Researchers analyzed nicotine-free, cinnamon-flavored e-cigarette vapor using gas chromatography-mass spectrometry (GC-MS) to identify specific chemicals that might impact zebrafish cardiovascular development.
Their analysis confirmed the presence of cinnamaldehyde and eugenol, compounds known to suppress cardiovascular function, as well as other unidentified compounds that might also contribute.
More research is needed to study the individual effects of these compounds on cardiovascular function during zebrafish development.
A joint study conducted by the Biology Departments of the University of Akron (Akron, Ohio) and Slippery Rock University (Slippery Rock, Pennsylvania) built upon their previous research focusing on respiratory effects associated with electronic cigarette use and their effects on other systems, including embryonic cardiovascular function and development due to maternal use during pregnancy, showing that exposing zebrafish embryos to nicotine-free cinnamon flavored electronic cigarette (e-cigarette) vapor resulted in the suppression of cardiovascular function. To determine which specific compounds were present in the vapor used in their prior study, non-targeted, qualitative gas chromatography-mass spectrometry (GC-MS) was performed. A paper based on this research was published in microPublication Biology (1).
The previous research indicated that chemical compounds in the vapor, apart from nicotine, can greatly affect heart function (2). In this study, qualitative, non-targeted (3) GC-MS was performed to confirm the presence of e-cigarette vapor in the zebrafish embryo’s water, validating the previous research’s exposure methods, as well as to identify which chemical compounds were present during the exposures to nicotine-free, cinnamon flavored, e-cigarette vapor (1).
Nicotine was found to be present in the nicotine-containing vapor, and it was confirmed to be absent in the nicotine-free vapor. Other chemical compounds that may have affected cardiovascular function in zebrafish were also identified in the analyzed vapors including cinnamaldehyde and eugenol among others (1).
The analysis confirmed the presence of cinnamaldehyde and eugenol, which may begin to explain the suppressive cardiovascular effect shown previously with embryo exposures to the nicotine-free, cinnamon flavored vapors (2). A primary component of clove oil and is a commonly used fish anesthetic (4), eugenol has also been shown in previous research to cause suppressive cardiovascular effects in rats (5). Cinnamaldehyde, an essential oil present in the bark of cinnamon trees and other species of the genus Cinnanomum (6), suppresses cardiovascular function through the inhibition of voltage gated L-type calcium channels (7).
The researchers pointed out that it is important to note that many other compounds besides cinnamaldehyde and eugenol were also present in the vapor-infused water, and any, or all, of them may be playing a role in the results shown previously by their previous research (2).They also stated that more work is needed for examination of the effects of nicotine-free, cinnamon flavored vapor with continued zebrafish development. Additionally, further work is needed concerning exposures to the individual compounds identified through their analysis for identification as to which of them may influence cardiovascular function throughout development (1).
References
1. Piechowski, J. M.; Bagatto, B. Qualitative Chemical Analysis of Cinnamon Flavored E-Cigarette Vapor to Identify Compounds of Interest That May Affect Cardiovascular Function. MicroPubl. Biol. 2025, 2025.DOI: 10.17912/micropub.biology.001605
2. Piechowski, J. M; Bagatto, B. Cardiovascular Function During Early Development Is Suppressed by Cinnamon Flavored, Nicotine-Free, Electronic Cigarette Vapor. Birth Defects Res. 2021, 113 (16),1215-1223. DOI: 10.1002/bdr2.1951
3. Berkelhamer, S. K.; Helman, J. M.; Gugino, S. F. et al. In Vitro Consequences of Electronic-Cigarette Flavoring Exposure on the Immature Lung. Int. J. Environ. Res. Public Health 2019, 16 (19), 3635. DOI: 10.3390/ijerph16193635
4. Grush, J.; Noakes, D. L.; Moccia, R. D. The efficacy of clove oil as an anesthetic for the zebrafish, Danio rerio (Hamilton). Zebrafish 2004, 1 (1), 46-53. DOI: 10.1089/154585404774101671
5. Lahlou, S.; Interaminense, L. F.; Magalhães, P. J. et al. Cardiovascular Effects of Eugenol, a Phenolic Compound Present in Many Plant Essential Oils, in Normotensive Rats. J. Cardiovasc. Pharmacol. 2004, 43 (2), 250-257. DOI: 10.1097/00005344-200402000-00013
6. Cinnamaldehyde. Wikipedia.https://en.wikipedia.org/wiki/Cinnamaldehyde
(accessed 2025-06-05)
7. Alvarez-Collazo, J.; Alonso-Carbajo, L.; López-Medina A. I. et al. Cinnamaldehyde Inhibits L-Type Calcium Channels in Mouse Ventricular Cardiomyocytes and Vascular Smooth Muscle Cells. Pflugers Arch. 2014, 466 (11), 2089-2099. DOI: 10.1007/s00424-014-1472-8
