Bitter Taste Receptor 46 (hTAS2R46) Protects Monocytes/Macrophages from Oxidative Stress.

Bitter taste receptors (TAS2Rs) are not only responsible for taste perception in the oral cavity, but are spread throughout the body, generating a widespread chemosensory system. In humans, 25 subtypes have been identified and are differentially expressed in tissues and organs, including in the immune system. In fact, several TAS2R subtypes have been detected in neutrophils, lymphocytes, B and T cells, NK cells, and monocytes/macrophages, in which they regulate various protective functions of the innate immune system. Given its recognized anti-inflammatory and antioxidant activity, and the generally protective role of bitter taste receptors, in this work, we studied TAS2R46's potential in the protection of human monocyte/macrophage DNA from stress-induced damage. Through both direct and indirect assays and a single-cell gel electrophoresis assay, we demonstrated that absinthin, a specific TAS2R46 agonist, counteracts the release of reactive oxygen species (ROS) and reactive nitrogen species (RNS) and reduces DNA damage in both cell types. Even though the release of ROS from monocytes/macrophages is fundamental for contrast pathogen agents, supraphysiological ROS production impairs their function, finally leading to cell death. Our results highlight TAS2R46 as a novel player involved in the protection of monocytes and macrophages from oxidative stress damage, while simultaneously supporting their antimicrobial activity.

Lifestyle Changes and Body Mass Index during COVID-19 Pandemic Lockdown: An Italian Online-Survey.

BACKGROUND: COVID-19 pandemic has imposed a period of contingency measures, including total or partial lockdowns all over the world leading to several changes in lifestyle/eating behaviours. This retrospective cohort study aimed at investigating Italian adult population lifestyle changes during COVID-19 pandemic "Phase 1" lockdown (8 March-4 May 2020) and discriminate between positive and negative changes and BMI (body mass index) variations (ΔBMI). METHODS: A multiple-choice web-form survey was used to collect retrospective data regarding lifestyle/eating behaviours during "Phase 1" in the Italian adult population. According to changes in lifestyle/eating behaviours, the sample was divided into three classes of changes: "negative change", "no change", "positive change". For each class, correlations with ΔBMI were investigated. RESULTS: Data were collected from 1304 subjects (973F/331M). Mean ΔBMI differed significantly (p < 0.001) between classes, and was significantly related to water intake, alcohol consumption, physical activity, frequency of "craving or snacking between meals", dessert/sweets consumption at lunch. CONCLUSIONS: During "Phase 1", many people faced several negative changes in lifestyle/eating behaviours with potential negative impact on health. These findings highlight that pandemic exacerbates nutritional issues and most efforts need to be done to provide nutrition counselling and public health services to support general population needs.