Comparative study of the effects of cigarette smoke versus next-generation tobacco and nicotine product extracts on inflammatory biomarkers of human monocytes.

Introduction:
This article presents a comparative study of the effects of cigarette smoke extract and next-generation tobacco and nicotine product extracts on inflammatory biomarkers of human monocytes. The study aims to understand the impact of these products on cell viability, anti-oxidant and pro-inflammatory gene and protein expression in ThP-1 monocytes.

Key Points:

* The study used aqueous smoke extracts (aqE) of a heated tobacco product (hTP), an electronic cigarette (e-cig), a conventional cigarette (3R4F), and pure nicotine (nic) for the experiment.
* Treatment with 3R4F reduced cell viability in a dose-dependent manner, while exposure to alternative smoking products showed no difference to control.
* at the highest non-lethal dose of 3R4F (20%), the following notable mRNa expression changes were observed for 3R4F, hTP, and e-cig respectively: hMOX1 (6-fold, < 2-fold, < 2-fold), NqO1 (3.5-fold, < 2-fold, < 2-fold), CCL2 (4-fold, 3.5-fold, 2.5-fold), IL1B (4-fold, 3-fold, < 2-fold), IL8 (5-fold, 2-fold, 2-fold), TNF (2-fold, 2-fold, < 2-fold), and ICaM1 was below the 2-fold threshold for all products.
* With respect to protein expression, IL1B (3-fold, < 2-fold, < 2-fold) and IL8 (3.5-fold, 2-fold, 2-fold) were elevated over the 2-fold threshold, whereas CCL2, TNF, and ICaM1 were below 2-fold expression for all products.
* at higher doses, greater inductions were observed with all extracts; however, NGP responses were typically lower than 3R4F.
* The study found that anti-oxidative and pro-inflammatory processes were activated by all products. NGPs overall showed lower responses relative to controls than ThP-1 cells exposed to 3R4F aqE.

Main Message:
The study suggests that next-generation tobacco and nicotine products (NGPs) have lower cytotoxic, oxidative, and pro-inflammatory effects on human monocytes compared to conventional cigarettes. however, NGPs can still activate anti-oxidative and pro-inflammatory mechanisms, albeit at higher doses. Therefore, it is essential to continue researching the potential health impacts of NGPs to ensure public safety.

Giebe S, Brux M, hofmann a, et al. Comparative study of the effects of cigarette smoke versus next-generation tobacco and nicotine product extracts on inflammatory biomarkers of human monocytes. Pflugers archiv : European journal of physiology. 2023;475(7):823-833. doi:10.1007/s00424-023-02809-9