Cultivated Enterococcus faecium B6 from children with obesity promotes nonalcoholic fatty liver disease by the bioactive metabolite tyramine.

Gut microbiota plays an essential role in nonalcoholic fatty liver disease (NAFLD). However, the contribution of individual bacterial strains and their metabolites to childhood NAFLD pathogenesis remains poorly understood. Herein, the critical bacteria in children with obesity accompanied by NAFLD were identified by microbiome analysis. Bacteria abundant in the NAFLD group were systematically assessed for their lipogenic effects. The underlying mechanisms and microbial-derived metabolites in NAFLD pathogenesis were investigated using multi-omics and LC-MS/MS analysis. The roles of the crucial metabolite in NAFLD were validated in vitro and in vivo as well as in an additional cohort. The results showed that Enterococcus spp. was enriched in children with obesity and NAFLD. The patient-derived Enterococcus faecium B6 (E. faecium B6) significantly contributed to NAFLD symptoms in mice. E. faecium B6 produced a crucial bioactive metabolite, tyramine, which probably activated PPAR-γ, leading to lipid accumulation, inflammation, and fibrosis in the liver. Moreover, these findings were successfully validated in an additional cohort. This pioneering study elucidated the important functions of cultivated E. faecium B6 and its bioactive metabolite (tyramine) in exacerbating NAFLD. These findings advance the comprehensive understanding of NAFLD pathogenesis and provide new insights for the development of microbe/metabolite-based therapeutic strategies.

Silver nitrate-assisted photo-crosslinking for enhancing the mechanical properties of an alginate/silk fibroin-based 3D scaffold.

Scaffolds play a pivotal role in tissue engineering and serve as vital biological substitutes, providing structural support for cell adhesion and subsequent tissue development. An ideal scaffold must possess mechanical properties suitable for tissue function and exhibit biodegradability. Although synthetic polymer scaffolds offer high rigidity and elasticity owing to their reactive side groups, which facilitate tailored mechanical and rheological properties, they may lack biological cues and cause persistent side effects during degradation. To address these challenges, natural polymers have garnered attention owing to their inherent bioactivity and biocompatibility. However, natural polymers such as silk fibroin (SF) and tyramine-modified alginate (AT) have limitations, including uncontrolled mechanical properties and weak structural integrity. In this study, we developed a blend of SF and AT as a printable biomaterial for extrusion-based 3D printing. Using photocrosslinkable SF/AT inks facilitated the fabrication of complex scaffolds with high printability, thereby enhancing their structural stability. The incorporation of silver nitrate facilitated the tunability of mechanical and rheological behaviors. SF/AT scaffolds with varying stiffness in the physiologically relevant range for soft tissues (51-246 kPa) exhibited excellent biocompatibility, indicating their promising potential for diverse applications in tissue engineering.

Hepatocellular carcinoma biomarkers screening based on hydrogel photonic barcodes with tyramine deposition amplified ELISA.

Hepatocellular carcinoma (HCC), as one of the most lethal cancers, significantly impacts human health. Attempts in this area tends to develop novel technologies with sensitive and multiplexed detection properties for early diagnosis. Here, we present novel hydrogel photonic crystal (PhC) barcodes with tyramine deposition amplified enzyme-linked immunosorbent assay (ELISA) for highly sensitive and multiplexed HCC biomarker screening. Because of the abundant amino groups of acrylic acid (AA) component, the constructed hydrogel PhC barcodes with inverse opal structure could facilitate the loading of antibody probes for subsequent detection of tumor markers. By integrating tyramine deposition amplified ELISA on the barcode, the detection signal of tumor markers has been enhanced. Based on these features, it is demonstrated that the hydrogel PhC barcodes with tyramine deposition amplified ELISA could realize highly sensitive and multiplexed detection of HCC-related biomarkers. It was found that this method is flexible, sensitive and accurate, suitable for multivariate analysis of low abundance tumor markers and future cancer diagnosis. These features make the newly developed PhC barcodes an innovation platform, which possesses tremendous potential for practical application of low abundance targets.

Fluorometric "AND" logic gate for detection of tyramine and tyrosinase based on in-situ formation of silicon-containing nanoparticles.

BACKGROUND: Tyramine is an important index of food freshness degree, and tyrosinase that can specifically oxidized monophenolamine to catecholamine plays a crucial part in the occurrence and development of melanin-related skin diseases. Therefore, it is crucial to develop sensitive and efficient methods for the detection of tyramine and tyrosinase. RESULTS: In this work, encouraged by tyrosinase-triggered specific oxidation of tyramine to dopamine and the unique fluorescent reaction between dopamine and amino silane, we have developed a one-step synthetic strategy of silicon containing nanoparticles (Si CNPs) for "turn-on" detection of tyramine and tyrosinase. The Si CNPs formed with thoroughly studied mechanism exhibit uniform structure and robust yellow-green fluorescence. The low detection limits for tyramine (1.87 µM) and tyrosinase (0.0029 U/mL) demonstrate admirable sensitivity outstripping most methods. The proposed assay achieves satisfactory results in the determination of tyramine and tyrosinase activity in real samples. Furthermore, we leverage this new fluorescent assay to enable the fabrication of an "AND" Boolean logic gate. SIGNIFICANCE: The entire process can be completed at easily available temperature and pressure with rapid response, convenient operation and visual observation. This fluorescent assay featured with excellent sensitivity, selectivity and stability has considerable prospects in the application of biosensors and disease diagnosis.

Quantitative tyramine analysis method for Apis mellifera larvae infected with Melissococcus plutonius, the causative agent of European foulbrood.

Tyramine, a trace monoamine produced from tyrosine by decarboxylation and found naturally in foods, plants, and animals, is a suspected virulence factor of Melissococcus plutonius that causes European foulbrood in honey bee brood. In the present study, we developed a method for quantitative analysis of tyramine in culture medium and honey bee larvae with a limit of quantitation of 3 ng/mL and a recovery rate of >97% using Liquid Chromatography-Mass Spectrometry/Mass Spectrometry and deuterium-labeled tyramine, demonstrating for the first time that a highly virulent M. plutonius strain actually produces tyramine in infected larvae. This method will be an indispensable tool to elucidate the role of tyramine in European foulbrood pathogenesis in combination with exposure bioassays using artificially reared bee larvae.

New aspects characterizing non-obese NAFLD by the analysis of the intestinal flora and metabolites using a mouse model.

Non-alcoholic fatty liver disease (NAFLD) is a major public health problem due to the high incidence affecting approximately one-third of the world's population. NAFLD is usually linked to obesity and excessive weight. A subset of patients with NAFLD expresses normal or low body mass index; thus, the condition is called non-obese NAFLD or lean NAFLD. However, patients and healthcare professionals have little awareness and understanding of NAFLD in non-obese individuals. Furthermore, preclinical results from non-obese animal models with NAFLD are unclear. Gut microbiota and their metabolites in non-obese/lean-NAFLD patients differ from those in obese NAFLD patients. Therefore, we analyzed the biochemical indices, intestinal flora, and intestinal metabolites in a non-obese NAFLD mouse model established using a methionine-choline-deficient (MCD) diet. The significantly lean MCD mice had a remarkable fatty liver with lower serum triglyceride and free fatty acid levels, as well as higher alanine transaminase and aspartate transaminase levels than normal mice. 16S RNA sequencing of fecal DNA showed that the overall richness and diversity of the intestinal flora decreased in MCD mice, whereas the Firmicutes:Bacteroidota ratio was increased. g_Tuzzerella, s_Bifidobacterium pseudolongum, and s_Faecalibaculum rodentium were the predominant species in non-obese NAFLD mice. Fecal metabolomics using liquid chromatography-tandem mass spectrometry revealed the potential biomarkers for the prognosis and diagnosis of non-obese NAFLD, including high levels of tyramine glucuronide, 9,12,13-TriHOME, and pantetheine 4'-phosphate, and low levels of 3-carbamoyl-2-phenylpropionaldehyde, N-succinyl-L,L-2,6-diaminopimelate, 4-methyl-5-thiazoleethanol, homogentisic acid, and estriol. Our findings could be useful to identify and develop drugs to treat non-obese NAFLD and lean NAFLD. IMPORTANCE: Patients and healthcare professionals have little awareness and understanding of NAFLD in non-obese individuals. In fact, about 40% of people with NAFLD worldwide are non-obese, and nearly one-fifth are lean. Lean NAFLD unfortunately may be unnoticed for years and remains undetected until hepatic damage is advanced and the prognosis is compromised. This study focused on the lean NAFLD, screened therapeutic agents, and biomarkers for the prognosis and diagnosis using MCD-induced male C57BL/6J mice. The metabolites tyramine glucuronide, 9,12,13-TriHOME, and pantetheine 4'-phosphate, together with the predominant flora including g_Tuzzerella, s_Bifidobacterium pseudolongum, and s_Faecalibaculum rodentium, were specific in non-obese NAFLD mice and might be used as targets for non-obese NAFLD drug exploration. This study is particularly significant for non-obese NAFLDs that need to be more actively noticed and vigilant.

Ultrasensitive fluorescence microRNA biosensor by coupling hybridization-initiated exonuclease I protection and tyramine signal amplification.

Tyramine signal amplification (TSA) has made its mark in immunoassay due to its excellent signal amplification ability and short reaction time, but its application in nucleic acid detection is still very limited. Herein, an ultrasensitive microRNA (miRNA) biosensor by coupling hybridization-initiated exonuclease I (Exo I) protection and TSA strategy was established. Target miRNA is complementarily hybridized to the biotin-modified DNA probe to form a double strand, which protects the DNA probe from Exo I hydrolysis. Subsequently, horseradish peroxidase (HRP) is attached to the duplex via the biotin-streptavidin reaction and catalyzes the deposition of large amounts of biotin-tyramine in the presence of hydrogen peroxide (H2O2), followed by the conjugation of signal molecule streptavidin-phycoerythrin (SA-PE), which generates an intense fluorescence signal upon laser excitation. This method gave broad linearity in the range of 0.1 fM - 10 pM, yielding a detection limit as low as 74 aM. An increase in sensitivity of 4 orders of magnitude was observed compared to the miRNA detection without TSA amplification. This biosensor was successfully applied to the determination of miR-21 in breast cancer cells and human serum. By further design of specific DNA probes and coupling with the Luminex xMAP technology, it could be easily extended to multiplex miRNA assay, which possesses great application potential in clinical diagnosis.

Riparin II-type benzamides as novel antibiofilm agents against dermatophytes: chemical synthesis, in vitro, ex vivo and in silico evaluation.

BACKGROUND: The ability of dermatophytes to develop biofilms in host tissues confers physical and biochemical resistance to antifungal drugs. Therefore, research to find new compounds against dermatophyte biofilm is crucial. OBJECTIVES: To evaluate the antifungal activity of riparin II (RIP2), nor-riparin II (NOR2) and dinor-riparin II (DINOR2) against Trichophyton rubrum, Microsporum canis and Nannizzia gypsea strains. METHODS: Initially, we determined the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of benzamides. We evaluated the inhibitory effects on the development of dermatophyte biofilms using in vitro and ex vivo models. Finally, we built three-dimensional models of the sulphite pump Ssu1 to investigate the interactions with the benzamides by molecular docking. RESULTS: RIP2 showed a broad spectrum of activity against T. rubrum, M. canis and N. gypsea, whereas NOR2 and DINOR2 were more selective. Furthermore, the shortening of the carbon chain from RIP2 benzamide to NOR2 and DINOR2 homologs caused a decrease in the MIC values. The benzamides reduced biofilm production and viability in vitro (P < 0.05) at MIC. This result was similar ex vivo in human nail fragments tests, but NOR2 and DINOR2 showed significant results at 2xMIC (P < 0.05). We constructed a model of the Ssu1 protein for each dermatophyte with high similarity. Molecular docking showed that the benzamides obtained higher binding energy values than ciclopirox. CONCLUSIONS: Our study shows the antibiofilm potential for riparin II-type benzamides as new drugs targeting dermatophytes by inhibiting the Ssu1 protein.

Tyramine-Invertase Bioconjugate-Amplified Personal Glucose Meter Signaling for Ultrasensitive Immunoassay.

Highly sensitive and facile detection of low levels of protein markers is of great significance for the early diagnosis and efficacy monitoring of diseases. Herein, aided by an efficient tyramine-signal amplification (TSA) mechanism, we wish to report a simple but ultrasensitive immunoassay with signal readout on a portable personal glucose meter (PGM). In this study, the bioconjugates of tyramine and invertase (Tyr-inv), which act as the critical bridge to convert and amplify the protein concentration information into glucose, are prepared following a click chemistry reaction. Then, in the presence of a target protein, the sandwich immunoreaction between the immobilized capture antibody, the target protein, and the horseradish peroxidase (HRP)-conjugated detection antibody is specifically performed in a 96-well microplate. Subsequently, the specifically loaded HRP-conjugated detection antibodies will catalyze the amplified deposition of a large number of Tyr-inv molecules onto adjacent proteins through highly efficient TSA. Then, the deposited invertase, whose dosage can faithfully reflect the original concentration of the target protein, can efficiently convert sucrose to glucose. The amount of finally produced glucose is simply quantified by the PGM, realizing the highly sensitive detection of trace protein markers such as the carcinoembryonic antigen and alpha fetoprotein antigen at the fg/mL level. This method is simple, cost-effective, and ultrasensitive without the requirement of sophisticated instruments or specialized laboratory equipment, which may provide a universal and promising technology for highly sensitive immunoassay for in vitro diagnosis of diseases.

Multi-crosslinked hydrogel built with hyaluronic acid-tyramine, thiolated glycol chitosan and copper-doped bioglass nanoparticles for expediting wound healing.

The migration of fibroblasts and endothelial cells is a critical determinant of wound-healing outcomes for skin injuries. Here, hyaluronic acid-tyramine (HAT) and thiolated glycol chitosan (TGC) conjugates were combined with copper-doped bioglass (ACuBG) nanoparticles to build a novel type of multi-crosslinked hydrogel for stimulating the migration of cells, and thus, expediting wound healing. The optimally devised HAT/TGC/ACuBG gels had markedly improved strength and stiffness compared to the gels built from either HAT or TGC while showing sufficient elasticity, which contributes to stimulating the migration of fibroblasts. The sustainable release of silicon and copper ions from the gels was found to jointly induce the migration of human umbilical vein endothelial cells. The results based on mouse full-thickness skin defects demonstrated that they were able to fully restore the skin defects with formation of complete appendages within two weeks, suggesting their promising potency for use in expediting wound healing.

[Metabolic Activities Catalyzed by Human Cytochrome P450 (CYP) 2D6 and CYP3A Subfamily Members and Effect of Various Compounds, Including Endogenous Steroid Hormones, on These Activities].

My research focused on the effects of various drugs on (1) dopamine formation from p-tyramine catalyzed by polymorphic cytochrome P450 (CYP or P450) 2D6 variants and (2) endogenous steroid hormone hydroxylation catalyzed by CYP3A subfamily members (CYP3A4, CYP3A5, CYP3A7). The activation (cooperativity) of metabolic reactions catalyzed by P450s was especially emphasized. The effects of various psychotropic agents on dopamine formation from p-tyramine, catalyzed by wild-type CYP2D6.1 and CYP2D6 variants, including CYP2D6.2 (Arg296Cys;Ser486Thr), CYP2D6.10 (Pro34Ser;Ser486Thr), and CYP2D6.39 (Ser486Thr) were compared. Michaelis (Km) and inhibition (Ki) constants of the psychotropic agents in the presence of CYP2D6.10 were higher than those observed in the presence of other CYP2D6 variants. Fluvoxamine, fluoxetine, milnacipran, and haloperidol activated CYP2D6-catalyzed dopamine formation [decreasing the Km and/or increasing the maximal velocity (kcat)], and this activation was CYP2D6 variant-dependent. Regarding the CYP3A subfamily, the effects of various compounds including endogenous steroid hormones on the 6ß-hydroxylation of steroid hormones, such as testosterone, progesterone, and cortisol, were determined; it was found that testosterone, dehydroepiandrosterone, and/or α-naphthoflavone activated 6ß-hydroxylation of cortisol and/or progesterone, but the effects varied in the presence of different CYP3A subfamily members. Further studies are required to confirm the mechanisms and therapeutic relevance of these activation phenomena.

Concomitant use of monoamine oxidase inhibitor and tyrosine in parenteral nutrition.

Monoamine oxidase inhibitors (MAOIs) prevent the breakdown of tyramine in the body, and can cause a sudden increase in blood pressure with significant tyramine build up. This phenomenon, when it occurs, is known as tyramine pressor response. It is unknown if tyrosine administered in parenteral nutrition (PN) leads to tyramine build-up with concomitant use of MAOIs. It is also unknown if PN patients who are taking MAOI are at risk for the tyramine pressor response. This is a theoretical possibility as tyrosine endogenously undergoes decarboxylation to produce tyramine. We describe our experience with a 67-year-old woman with severe depression who was on the MAOI, transdermal selegiline. Her clinical course was complicated by an inability to take adequate per oral (PO) intake and she met criteria for unspecified severe protein-calorie-malnutrition in the context of social or environmental circumstances. Therefore, she required PN initiation. PlenamineTM (B. Braun, Bethlehem, PA, USA) was used as the amino acid source in the PN, which contains 39 mg of tyrosine per 100 ml of solution. The patient was monitored closely for any signs of hypertensive crisis while on PN and selegiline. She safely tolerated the combined therapy without any side effects. This is the first documented report of co-administration of PN containing tyrosine along with a MAOI. Our findings suggest that the dose of selegiline used in this patient can be co-administered safely in the setting of PN. However, further study is needed to verify our findings beyond this one patient. In conclusion, we recommend initiating PN and increasing it to goal in patients taking MAOIs, gradually, while monitoring for hypertensive crisis given the theoretical possibility of the tyramine pressor response.

Three new phenylpropanoid glucosides and a new tyramine-type alkamide from Piper puberulum.

Three new phenylpropanoid glycosides, piperpubelide (1), 1-propionyl-3-hydroxy-phenyl-4-O-ß-D-glucopyranoside (2), and 1-propionyl-4-hydroxy-phenyl-3-O-ß-D-glucopyranoside (3), a new tyramine-type alkamide, puberulumine L (4), together with thirteen known compounds (5-17) were isolated from Piper puberulum (Benth.) Maxim. Their structures were elucidated by analysis of spectroscopic data involving NMR, IR, UV, and HRESIMS data. Calculated and experimental ECD was used to confirm the configuration of compound 1. Compounds 14, 16, and 17 exhibited relatively positive DPPH radical scavenging activities, with corresponding EC50 of 10.23, 24.12, and 21.83 µM, respectively. In addition, compound 5 inhibited LPS-induced NO production in BV-2 microglia with an IC50 value of 18.05 µM.

Enzymatic Dimerization-Induced Self-Assembly of Alanine-Tyramine Conjugates into Versatile, Uniform, Enzyme-Loaded Organic Nanoparticles.

Herein, we report a novel enzymatic dimerization-induced self-assembly (e-DISA) procedure that converts alanine-tyramine conjugates into highly uniform enzyme-loaded nanoparticles (NPs) or nanocontainers by the action of horseradish peroxidase (HRP) in an aqueous medium under ambient conditions. The NP formation was possible with both enantiomers of alanine, and the average diameter could be varied from 150 nm to 250 nm (with a 5-12 % standard deviation of as-prepared samples) depending on the precursor concentration. About 60 % of the added HRP enzyme was entrapped within the NPs and was subsequently utilized for post-synthetic modification of the NPs with phenolic compounds such as tyramine or tannic acid. One-pot multi-enzyme entrapment of glucose oxidase (GOx) and peroxidase (HRP) within the NPs was also achieved. These GOx-HRP loaded NPs allowed multimodal detection of glucose, including that present in human saliva, with a limit of detection (LoD) of 740 nM through fluorimetry. The NPs exhibited good cytocompatibility and were stable to changes in pH (acidic to basic), temperature, ultrasonication, and even the presence of organic solvent (EtOH) to a certain extent, since they are stabilized by intermolecular hydrogen bonding, π-π, and CH-π interactions. The proposed e-DISA procedure can be widely expanded through the design of diverse enzyme-responsive precursors.

Disposable biosensor based on ionic liquid, carbon nanofiber and poly(glutamic acid) for tyramine determination.

In this study, an electrochemical biosensor based on carbon nanofibers (CNF), ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate (IL), poly(glutamic acid) (PGA) and tyrosinase (Tyr) modified screen printed carbon electrode (SPE) was constructed for tyramine determination. Optimum experimental parameters such as CNF and IL amount, polymerization conditions of glutamic acid, enzyme loading, pH of test solution and operating potential were explored. The construction steps of the Tyr/PGA/CNF-IL/SPE were pursued by scanning electron microscopy and cyclic voltammetry. The Tyr/PGA/CNF-IL/SPE biosensor exhibited linear response to tyramine in the range of 2.0 × 10-7 - 4.8 × 10-5 M with a low detection limit of 9.1 × 10-8 M and sensitivity of 302.6 µA mM-1. The other advantages of Tyr/PGA/CNF-IL/SPE include its high reproducibility, good stability and anti-interference ability. The presented biosensor was also applied for tyramine determination in malt drink and pickle juice samples and mean analytical recoveries of spiked tyramine were calculated as 100.6% and 100.4% respectively.

Gelatin-tyramine addition and low hydrogel density improves cell attachment, migration, and metabolic activity in vitro and tissue response in vivo in enzymatically crosslinkable dextran-hyaluronic acid hydrogels.

Hydrogels are receiving increasing attention for their use in 3D cell culture, tissue engineering, and bioprinting applications. Each application places specific mechanical and biological demands on these hydrogels. We developed a hydrogel toolbox based on enzymatically crosslinkable polysaccharides via tyramine (TA) moieties, allowing for rapid and tunable crosslinking with well-defined stiffness and high cell viability. Including gelatin modified with TA moieties (Gel-TA) improved the hydrogels' biological properties; 3 T3 fibroblasts and HUVECs attached to and proliferated on the enriched hydrogels at minute Gel-TA concentrations, in contrast to bare or unmodified gelatin-enriched hydrogels. Moreover, we were able to switch HUVECs from a quiescent to a migratory phenotype simply by altering the ligand concentration, demonstrating the potential to easily control cell fate. In encapsulation studies, Gel-TA significantly improved the metabolic activity of 3 T3 fibroblasts in soft hydrogels. Furthermore, we showed rapid migration and network formation in Gel-TA enriched hydrogels in contrast to a non-migratory behavior in non-enriched polysaccharide hydrogels. Finally, low hydrogel density significantly improves tissue response in vivo with large infiltration and low fibrotic reaction. Further development by adding ECM proteins, peptides, and growth factor adhesion sites will lead to a toolbox for hydrogels tailored toward their desired application.

Branched tyramides from males of the harvester ant, Pogonomyrmex badius.

Tyramides are produced in microgram quantities by males of species in the large Myrmicine ant sub-family (> 7000 species). Tyramides are transferred to female sexuals during mating where a specific female sexual evolved enzyme hydrolyzes the tyramides to the biogenic amine, tyramine. Tyramine is a ligand for receptors that rapidly activate reproductive development in the newly mated queen-previously reproductively inhibited by the mother queen. Without this elaborate biogenic amine precursor and co-evolved female sexual derived tyramide hydrolase, the defenseless newly mated queen's worker production would be delayed by up to 6 days, which could be lethal to the new queen. This is one of possibly several ant species separation mechanisms evolved to maintain species integrity. Here we report two methyl-branched tyramides from harvester ant, Pogonomyrmex badius, males, including one highly branched tyramide not previously reported.

Tyramine, one quorum sensing inhibitor, reduces pathogenicity and restores tetracycline susceptibility in Burkholderia cenocepacia.

Burkholderia cenocepacia is an opportunistic respiratory pathogen of particular relevance to patients with cystic fibrosis (CF), primarily regulating its biological functions and virulence factors through two quorum sensing (QS) systems (CepI/R and CciI/R). The highly persistent incidence of multidrug resistant Burkholderia cenocepacia poses a global threat to public health. In this study, we investigated the effects of tyramine, one biogenic amine, on the QS systems of Burkholderia cenocepacia. Genetic and biochemical analyses revealed that tyramine inhibited the production of N-hexanoyl-homoserine (AHL) signaling molecules (C8-HSL and C6-HSL) by blocking the CepI/R and CciI/R systems. As a result, the inhibition of QS systems leads to reduced production of various virulence factors, such as biofilm formation, extracellular polysaccharides, lipase, and swarming motility. Notably, as a potential quorum sensing inhibitor, tyramine exhibits low toxicity in vivo in Galleria mellonella larvae and is well characterized by Lipinski's five rules. It also shows high gastrointestinal absorption and the ability to cross the blood-brain barrier according to SwissADME database and ProTox-II server. Additionally, tyramine was found to enhance the efficacy of tetracycline in reducing the infectivity of Burkholderia cenocepacia in Galleria mellonella larvae infection model. Therefore, tyramine could be a promising candidate for combination therapy with traditional antimicrobials to improve their effectiveness against Burkholderia cenocepacia.

In silico investigation on interaction of small Ag6 nano-particle cluster with tyramine neurotransmitter.

The interaction of tyramine neurotransmitter with silver nano-particle (Ag6) cluster is explored in terms of the molecular structure, electronic properties and NBO analysis of tyramine-AgNPs bio-molecular conjugate. The adsorption mechanism of tyramine onto the Ag6 cluster has been investigated through computing of the electronic and geometrical properties in addition to the adsorption energies in various possible configurations. The magnitude of adsorption energy corresponding to the most favorable tyramine-Ag6 bio-molecular conjugate has been computed to be - 14.36 kcal/mol in the gas phase, which infers a good adsorption of tyramine with AgNPs cluster suggesting the practical applications of tyramine-AgNPs bio-molecular conjugates in bio-sensing, drug delivery, bio-imaging and other applications. Different electronic properties such as the energy gap of HOMO-LUMO, Fermi level and work function have been investigated in detail. Moreover, the effect of aqueous media on adsorption energy and electronic properties of the most favorable tyramine-AgNPs bio-molecular conjugate is investigated in order to understand the impact of the real biological situation.

Nutrigenomics: SNPs correlated to Food Preferences and Susceptibilities.

Background: Nutrigenomics explores the intricate interplay between single nucleotide polymorphisms (SNPs), food preferences, and susceptibilities. Methods: This study delves into the influence of SNPs on food sensitivities, allergies, tyramine intolerance, and taste preferences. Genetic factors intricately shape physiological reactions to dietary elements, with polymorphisms contributing to diverse sensitivities and immune responses. Results: Tyramine intolerance, arising from metabolic inefficiencies, unveils genetic markers exerting influence on enzyme function. SNPs transcend genetic diversity by exerting substantial impact on food sensitivities/allergies, with specific variants correlating to heightened susceptibilities. Genes accountable for digesting food components play pivotal roles. Given the rising prevalence of food sensitivities/allergies, understanding genetic foundations becomes paramount. In the realm of taste and food preferences, SNPs sculpt perception and choice, yielding variances in taste perception and preferences for sweetness, bitterness, and umami. This genetic medley extends its reach to encompass wider health implications. Conclusions: In this review article, we have focused on how polymorphisms wield significant sway over physiological responses, sensitivities, and dietary inclinations. Unraveling these intricate relationships illuminates the path to personalized nutrition, potentially revolutionizing tailored recommendations and interventions.