Search Results (4)

Artemisia absinthium L. is a medicinal plant well known for the bitterness of its sesquiterpenoids. To mask its intense taste while preserving these active compounds, an ethanolic extract (AAE) was prepared, and two microencapsulation techniques (spray drying and ionotropic gelation) were investigated under different process conditions. The best-performing formulation was selected for larger-scale production and a characterisation of the microparticles (MPs) was carried out. MPs were then incorporated into baked products (biscuits), which were subsequently characterised for proximate composition, total phenolic content (TPC) and antioxidant activity (AA). Bitter compounds were quantified through HPLC-DAD. A panel test was conducted on 50 volunteers, which compiled a satisfactory questionnaire. Ionotropic gelation proved to be the most suitable technique for producing AAE alginate-based MPs for incorporation into biscuit dough, yielding a product with a desirable particle size and flowability. The biscuits still retained a significant amount of TPC and AA, indicating that microencapsulation is a suitable strategy. Data from the acceptance questionnaire revealed that biscuits containing MPs loaded with absinthin-rich extract were comparable to the control ones regarding overall acceptance. In conclusion, a promising product was developed that effectively masks the bitterness of appetite-modulating bioactive compounds, with significant health-promoting potential. However, further investigation into the biological effects (e.g., hormonal responses, feelings of hunger, etc.) of these baked products is required. Full article

Bitter taste receptors (TAS2Rs) are expressed in extraoral tissues, exerting several functions and generating a whole-body chemosensory and protective system. TAS2Rs expression has been observed in the gastrointestinal tract, although their role is poorly understood. This study aims to investigate the role of TAS2R38 and 46 in human intestinal smooth muscle cells (HISMCs) after activation with the specific bitter ligands phenylthiocarbamide and absinthin, respectively. We found that TAS2R38 and 46 activation by phenylthiocarbamide (PTC) and absinthin, respectively, induces a rapid membrane depolarization and increase of cytosolic calcium levels due to internal storage in the IP₃ pathway, resulting in an accelerated cell contraction. Overall, this study unravels, for the first time, the contractile impact of these TAS2R subtypes on intestinal smooth muscle cells, suggesting their involvement in gut peristalsis and recommending these receptors as possible targets for new therapies. Full article

Bitter taste receptors (TAS2Rs) expressed in extraoral tissues represent a whole-body sensory system, whose role and mechanisms could be of interest for the identification of new therapeutic targets. It is known that TAS2R46s in pre-contracted airway smooth muscle cells increase mitochondrial calcium uptake, leading to bronchodilation, and that several SNPs have been identified in its gene sequence. There are very few reports on the structure–function analysis of TAS2Rs. Thus, we delved into the subject by using mutagenesis and in silico studies. We generated a cellular model that expresses native TAS2R46 to evaluate the influence of the four most common SNPs on calcium fluxes following the activation of the receptor by its specific ligand absinthin. Then, docking studies were conducted to correlate the calcium flux results to the structural mutation. The analysed SNPs differently modulate the TAS2R46 signal cascade according to the altered protein domain. In particular, the SNP in the sixth transmembrane domain of the receptors did not modulate calcium homeostasis, while the SNPs in the sequence coding for the fourth transmembrane domain completely abolished the mitochondrial calcium uptake. In conclusion, these results indicate the fourth transmembrane domain of TAS2R46 is critical for the intrinsic receptor activity. Full article

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. Full article