Lin Weihong, Hill Thomas, Stroup Andrea M, Sarles Samantha Emma, Ogura Tatsuya, Augustine Farhan, O'Sullivan Sean, Rahman Irfan, Robinson Risa, Jabba Sairam V, Nuss Caleb, Hensel Edward
Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, MD 21250, United States.
Division of Nonclinical Science, Center for Tobacco Products, U.S. Food and Drug Administration, Silver Spring, MD 20993, United States.
Toxicol Sci. 2025 Oct 1;207(2):261-271. doi: 10.1093/toxsci/kfaf090.
Chemosensory systems detect and discriminate a wide variety of molecules to monitor internal and external chemical environments. They initiate olfactory, gustatory, and chemesthetic sensations; influence human brain cognition and emotion; and guide a wide variety of behaviors essential for survival, including protective reactions, such as avoidance of contaminated foods and potential toxicants. Electronic nicotine delivery systems (ENDS) aerosolize e-liquids for inhaled consumption that typically contain flavorants, propylene glycol, vegetable glycerin, and nicotine. E-liquid aerosols also contain toxicants, such as formaldehyde, acetaldehyde, acrolein, and heavy metals. Chemosensory evaluation of ENDS aerosol plays an essential role in the assessment of whether a product will attract new users of all ages, as well as determining their likely use patterns, perceptions of product harm, satisfaction, and product selection. Nicotine and individual flavorant constituents stimulate multiple sensory receptor systems in complex patterns, initiating distinctive sensory perceptions depending on the chemical properties and quantity in the aerosol. There are limited data on chemosensory evaluation of ENDS aerosols and their influence on ENDS use and protective biologic mechanisms. This two-part manuscript provides an overview of (i) the physiology of the olfactory, gustatory, and chemesthetic chemosensory systems, their detection mechanisms, and their role in protective defenses; and (ii) the in vitro, in vivo, and in silico computer-based methodology available to evaluate ENDS irritants and toxicants, their impact on chemosensory pathways, the current state of the science related to e-liquid and ENDS aerosols, and challenges for future studies and scientific innovation.
化学感应系统能够检测并区分各种各样的分子，以监测内部和外部化学环境。它们引发嗅觉、味觉和化学感觉；影响人类大脑的认知和情感；并引导各种生存所必需的行为，包括保护性反应，如避免食用受污染的食物和潜在毒物。电子尼古丁传送系统（ENDS）将电子烟液雾化以供吸入使用，电子烟液通常含有调味剂、丙二醇、蔬菜甘油和尼古丁。电子烟液气溶胶还含有毒物，如甲醛、乙醛、丙烯醛和重金属。对ENDS气溶胶进行化学感应评估，对于评估一种产品是否会吸引所有年龄段的新用户，以及确定他们可能的使用模式、对产品危害的认知、满意度和产品选择起着至关重要的作用。尼古丁和个别调味剂成分以复杂的模式刺激多种感觉受体系统，根据气溶胶中的化学性质和数量引发独特的感官认知。关于ENDS气溶胶的化学感应评估及其对ENDS使用和保护性生物机制的影响的数据有限。这篇分两部分的手稿概述了：（i）嗅觉、味觉和化学感觉化学感应系统的生理学、它们的检测机制以及它们在保护性防御中的作用；（ii）可用于评估ENDS刺激物和毒物的体外、体内和基于计算机模拟的方法、它们对化学感应途径的影响、与电子烟液和ENDS气溶胶相关的科学现状，以及未来研究和科学创新面临的挑战。
