Rationale: The growing interest in regulating flavoured E-liquids must incorporate understanding of the "flavouring profile" of each E-liquid - which flavourants (flavouring chemicals) are present and at what concentrations not just focussing on the flavour on the label. Methods: We investigated the flavouring profile of 10 different flavoured E-liquids. We assessed bronchial epithelial cell viability and apoptosis, phagocytosis of bacteria and apoptotic cells by macrophages after exposure to E-cigarette vapour extract (EVE). And validated in normal human bronchial epithelial cells (NHBE) and alveolar macrophages (AMs) from healthy donors. We also assessed cytokine release and validated in the saliva from E-cigarette users. Results: Increased necrosis/apoptosis (16.1-64.5% apoptosis) in 16HBE cells was flavour dependent, and NHBEs showed an increased susceptibility to flavours. In THP-1 differentiated macrophages phagocytosis was also flavour dependent, with alveolar macrophages (AM) also showing increased susceptibility to flavours. Furthermore, Banana and Chocolate were shown to reduce surface expression of phagocytic target recognition receptors on alveolar macrophages. Banana and Chocolate increased IL-8 secretion by NHBE, whilst all 4 flavours reduced AM IL-1β secretion which was also reduced in the saliva of E-cigarette users compared with healthy controls. Flavourant profiles of E-liquids varied from simple 2 compound mixtures to complex mixtures containing over a dozen flavourants. E-liquids with high benzene content, complex flavouring profiles, high chemical concentration had the greatest impacts. Conclusions: The flavourant profile of E-liquids is key to disruption of the airway status quo by increasing bronchial epithelial cell apoptosis, causing alveolar macrophage phagocytic dysfunction and altering airway cytokines.

中文翻译：

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电子烟和健康风险：不仅仅是名字的味道

理由：对调节调味电子烟油的兴趣日益浓厚，必须了解每种电子烟油的“风味特征”——存在哪些调味剂（调味化学品）以及浓度，而不仅仅是关注标签上的风味。方法：我们调查了 10 种不同风味的电子烟油的风味特征。我们评估了暴露于电子烟蒸气提取物 (EVE) 后，巨噬细胞对支气管上皮细胞的活力和凋亡、吞噬细菌和凋亡细胞的作用。并在来自健康供体的正常人支气管上皮细胞 (NHBE) 和肺泡巨噬细胞 (AMs) 中得到验证。我们还评估了电子烟使用者唾液中的细胞因子释放和验证。结果：16HBE 细胞中的坏死/凋亡（16.1-64.5% 凋亡）增加是风味依赖性的，和 NHBE 对味道的敏感性增加。在 THP-1 分化的巨噬细胞中，吞噬作用也依赖于味道，肺泡巨噬细胞 (AM) 也表现出对味道的敏感性增加。此外，香蕉和巧克力显示可降低肺泡巨噬细胞上吞噬目标识别受体的表面表达。香蕉和巧克力增加了 NHBE 的 IL-8 分泌，而所有 4 种口味都减少了 AM IL-1β 的分泌，与健康对照组相比，电子烟使用者唾液中的 AM IL-1β 分泌也减少了。电子烟油的风味成分从简单的 2 种化合物混合物到包含十几种风味剂的复杂混合物不等。苯含量高、风味特征复杂、化学浓度高的电子烟油的影响最大。结论：