An in Vitro Study of Constituents Released from Smokeless Tobacco Products into Human Saliva.

Introduction:
This article reports the results of a study that examines the release of harmful and potentially harmful constituents (HPHCs) from four certified reference smokeless tobacco (ST) products into human saliva. The study compares the effects of tobacco cut size and product format (pouched or unpouched) on HPHCs release.

Key Points:

* Four certified reference ST products, including loose leaf chewing tobacco, Swedish-style snus, snus, and moist snuff, were used in the study.
* The ST products were incubated in human saliva at 37°C for various times to evaluate the release of HPHCs.
* The amounts of alkaloids (nicotine and cotinine), tobacco-specific N-nitrosamines (TSNAs) (N’-nitrosornicotine and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone), and benzo[α]pyrene (B[α]P) in the reference ST products and saliva samples were determined using gas chromatography–mass spectrometry (GC–MS), gas chromatography–flame ionization detection (GC–FID), or ultra-performance liquid chromatography–tandem mass spectrometry (UPLC–MS-MS).
* The amounts of each constituent released from the reference ST products were altered by the tobacco cut size and product format.
* Constituents (TSNAs and alkaloids) in moist snuff and loose leaf chewing tobacco were released faster compared to those in Swedish-style snus and snus.
* B[α]P was only detected in reference moist snuff samples, and only 3.4% of the total B[α]P was released into human saliva after incubation for 60 minutes.
* Higher percentages of total TSNAs and alkaloids were released at different rates from the four reference ST products.

Main Message:
The study highlights the importance of evaluating the release of HPHCs from ST products into human saliva, as the amounts of these constituents can vary based on tobacco cut size and product format. The study also underscores the need for further research to fully understand the impact of ST product use on human health. The results can inform regulatory efforts aimed at reducing the health risks associated with ST product use.

Guan, S., Bush, L., & Ji, H. (2022). An in Vitro Study of Constituents Released from Smokeless Tobacco Products into Human Saliva. Journal of Analytical Toxicology, 46(6), 625–632. https://doi.org/10.1093/jat/bkab076