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1.
Spectrochim Acta A Mol Biomol Spectrosc ; 279: 121495, 2022 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-35700610

RESUMO

Herein, we examined the modulatory effects ofApocynum (APO) on Monosodium Glutamate (MSG)-induced oxidative damage on the brain tissue of rats after long-term consumption of blood serum components by biochemical assays, Fourier transform infrared spectroscopy(FTIR), and machine learning methods. Sprague-Dawley male rats were randomly divided into the Control, Control + APO, MSG, and MSG + APO groups (n = 8 per group). All administrations were made by oral gavage saline, MSG, or APO and they were repeated for 28 days of the experiments. Brain tissue and blood serum samples were collected and analyzed for measurement levels ofmalondialdehyde (MDA),glutathione (GSH),myeloperoxidase (MPO), superoxide dismutase (SOD) activity, and Spectroscopic analysis. After 29 days, the results were evaluated using machine learning (ML). The levels of MDA and MPO showed changes in the MSG and MSG + APO groups, respectively. Changes in the proteins and lipids were observed in the FTIR spectra of the MSG groups. Additionally, APO in these animals improved the FTIR spectra to be similar to those in the Control group. The accuracy of the FTIR results calculated by ML was 100%. The findings of this study demonstrate that Apocynin treatment protectsagainst MSG-induced oxidative damage by inhibitingreactive oxygen speciesand upregulatingantioxidant capacity, indicating its potential in alleviatingthe toxic effects of MSG.


Assuntos
Estresse Oxidativo , Glutamato de Sódio , Acetofenonas , Animais , Encéfalo/metabolismo , Glutationa/metabolismo , Aprendizado de Máquina , Masculino , Ratos , Ratos Sprague-Dawley , Glutamato de Sódio/metabolismo , Glutamato de Sódio/farmacologia
3.
Enzyme Microb Technol ; 159: 110053, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35537377

RESUMO

In the bioproduction of glutaric acid, an emerging bioplastic monomer, α-ketoglutaric acid (α-KG) is required as an amine acceptor for 4-aminobutyrate aminotransferase (GabT)-driven conversion of 5-aminovalerate (5-AVA) to glutarate semialdehyde. Herein, instead of using expensive α-KG, an indirect α-KG supply system was developed using a relatively cheap alternative, monosodium glutamate (MSG), for l-glutamate oxidase (Gox)-based whole-cell conversion. Using 200 mM 5-AVA and 30 mM MSG initially with Gox, 67.1 mM of glutaric acid was produced. By applying the stepwise feeding strategy of MSG, the glutaric acid production capability was increased to 159.1 mM glutaric acid with a conversion yield of 79.6%. In addition, a buffer-free one-pot reaction from l-lysine was also applied in a 5 L bioreactor to evaluate its industrial applicability, resulting in a conversion yield of 54.2%. The system developed herein might have great potential for the large-scale, economically feasible production of glutaric acid by whole-cell conversion.


Assuntos
Escherichia coli , Glutamato de Sódio , Glutaratos , Ácidos Cetoglutáricos
4.
Am J Bot ; 109(6): 952-965, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35608078

RESUMO

PREMISE: Plants endemic to oceanic archipelagos are suitable for studying evolution, being isolated on substrates of different ages. Evolution has been recent, rendering traditionally employed sequences insufficiently variable for resolving relationships. This study includes sampling in the genus Tolpis (Asteraceae) from the Azores, Madeira, and Cape Verde, and expands upon an earlier study demonstrating the efficacy of multiplexed shotgun genotyping (MSG) for resolving relationships in Canarian Tolpis. METHODS: Genomic libraries for 90 accessions of Tolpis and two from the outgroup were generated for genotyping individuals using MSG. Loci were de novo assembled with iPyrad, which clusters MSG loci within and between samples. A maximum likelihood phylogeny was generated with RAxML. Ancestral area reconstruction was inferred using R package BioGeoBEARS. RESULTS: MSG data recovered a highly resolved phylogeny from population to inter-archipelago levels. Ancestral area reconstruction provided biogeographic hypotheses for the radiation of Macaronesian Tolpis. CONCLUSIONS: Four major clades were resolved. The Madeiran endemic T. macrorhiza is sister to other Tolpis. Species from the Canaries, Cape Verdes, and the continent are sister to T. succulenta from Madeira, which has a sister subclade of Azorean populations composed of T. succulenta and T. azorica. Population-level resolution suggests unrecognized taxa on several archipelagos. Ancestral reconstruction suggests initial dispersal from the continent to Madeira, with dispersal to the Azores, then dispersal from Madeira to the Canary Islands, with both subsequent dispersal to the Cape Verdes and back-dispersal to the continent. Single-island radiations and inter-island dispersal are implicated in divergence in Macaronesian Tolpis.


Assuntos
Asteraceae , Glutamato de Sódio , Asteraceae/genética , Açores , Genótipo , Filogenia
5.
PLoS One ; 17(5): e0268668, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35617216

RESUMO

The salivary gland can be permanently impaired by radiation treatment for head and neck cancers. Efforts at tissue regeneration have focused on saliva-producing acinar cells. However, myoepithelial cells are also critical to gland function, but mechanisms that regulate their differentiation are poorly defined. To study myoepithelial differentiation, we employed mSG-PAC1 murine salivary gland epithelial cells. We demonstrate that mSG-PAC1 spheroids exhibit phenotypic plasticity between pro-acinar and myoepithelial cell fates. Increased expression of pro-acinar/acinar or myoepithelial RNAs was identified from spheroids cultured under different media conditions by microarray followed by gene-set enrichment analysis. Spheroids cultured with different medium components expressed proteins typical of either acinar or myoepithelial cells, as detected by immunocytochemistry. We demonstrate that the pattern of TAZ expression in the epithelial compartment of the differentiating murine salivary gland correlates with the expression of the myoepithelial marker alpha-SMA, as is the case for TAZ expression in mSG-PAC1 spheroids. Our analysis also indicates that YAP/TAZ target genes are upregulated together with myoepithelial markers. Importantly, siRNA targeting of TAZ expression in mSG-PAC1 spheroids diminished the expression of myoepithelial markers. Our results in this in vitro cell model implicate TAZ signaling in myoepithelial differentiation.


Assuntos
Glândulas Salivares , Glutamato de Sódio , Células Acinares/metabolismo , Animais , Diferenciação Celular , Células Epiteliais/metabolismo , Camundongos , Glândulas Salivares/metabolismo
6.
Front Immunol ; 13: 862702, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35572527

RESUMO

Objective: To establish an artificial intelligence-based method to quantitatively evaluate subtle pathological changes in retinal nerve cells and synapses in monosodium glutamate (MSG) mice and provide an effective animal model and technique for quantitative evaluation of retinal neurocytopathies. Methods: ICR mice were subcutaneously injected with MSG to establish a model of metabolic syndrome. We then established a mouse model of type 1 diabetes, type 2 diabetes, and KKAy mouse model as control. The HE sections of the retina were visualized using an optical microscope. AI technology was used for quantitative evaluation of the retinal lesions in each group of rats. The surface area custom parameters of the retinal nerve fiber layer (RNFL), inner plexiform layer (IPL), inner nuclear layer (INL), and outer plexiform layer (OPL) were defined as SR, SIPL, SINL, and SOPL, respectively. Their heights were defined as HR, HIPL, HINL, and HOPL, and the number of ganglion cells was defined as A. Then, the attention-augmented fully convolutional Unet network was used to segment the retinal HE images, and AI technology to identify retinal neurocytopathies quantitatively. Results: The attention-augmented fully convolutional Unet network increased PA and IOU parameters for INL, OPL, RNFL, and ganglion cells and was superior in recognizing fine structures. A quantitative AI identification of the height of each layer of the retina showed that the heights of the IPL and INL of the MSG model were significantly less than those of the control groups; the retinas of the other diabetic models did not exhibit this pathological feature. The RNFLs of type 2 diabetes were thinner, and the characteristics of retinopathy were not obvious in the other animal models. The pathological changes seen on HE images were consistent with the results of the quantitative AI evaluation. Immunohistochemistry results showed that NMDAR2A, GluR2, and NRG1 were significantly downregulated in the retina of MSG mice. Conclusions: The MSG retinopathy model is closely associated with neurotransmitter abnormalities and exhibits important characteristics of retinal neurodegeneration, making it suitable for studying retinal neurocytopathies. The AI recognition technology for retinal images established in the present study can be used for the quantitative and objective evaluation of drug efficacy.


Assuntos
Diabetes Mellitus Tipo 2 , Neuropatias Diabéticas , Retinopatia Diabética , Animais , Inteligência Artificial , Diabetes Mellitus Tipo 2/patologia , Retinopatia Diabética/induzido quimicamente , Retinopatia Diabética/patologia , Modelos Animais de Doenças , Camundongos , Camundongos Endogâmicos ICR , Ratos , Retina/patologia , Células Ganglionares da Retina/patologia , Glutamato de Sódio/toxicidade
7.
Biosens Bioelectron ; 210: 114304, 2022 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-35550938

RESUMO

Umami substances are nutrients to humans, and their synergistic effect is associated with food acceptance. In this study, a new biosensor was developed to detect umami substances, their synergistic effect, and detection kinetics. Porcine taste-bud tissues were used as the sensing element, and the umami substance signals were characterized using an electrochemical workstation. The responses of taste-bud tissue sensors to monosodium L-glutamate (MSG) were compared based on different tongue sites. The interaction law between MSG and receptors in the taste-bud tissues of the three sensors conforms to enzymatic-reaction kinetics, where rectangular hyperbola curves in the Michaelis-Menten equation were followed with fitting coefficients (>0.91). However, the taste-bud sensors respond differently to MSG stimuli, with those based on a tip and mediolateral tongue, producing the lowest detection limit of 10-16 mol/L. The number of receptors required for a single cell to achieve maximum output signal is 3.68, 30.42, and 7.27, respectively. Moreover, the taste-bud tissue sensors identified the synergistic effect of umami substances. In addition, they were sensitive to umami variations in soy sauce and mandarin fish. The developed porcine taste-bud tissue biosensor revealed the interaction law between umami substances and receptors, providing a new idea for umami evaluation.


Assuntos
Técnicas Biossensoriais , Papilas Gustativas , Animais , Cinética , Glutamato de Sódio/química , Suínos , Paladar , Papilas Gustativas/fisiologia
8.
Food Chem ; 387: 132890, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-35397267

RESUMO

The demand for low-salt foods is increasing due to their health benefits. Umami is known to enhance salty, and a large amount of umami components have been identified in edible fungi. 5'-nucleotides and umami amino acids from nine species of edible fungi were quantified. The equal umami concentration (EUC) in nine edible fungi was within the range of 37.7-1317.72 g MSG/100 g, and umami intensity as determined by electronic tongue and sensory evaluation was within the range of 11.22-13.53 and 2.85-5.55, respectively. Antler fungus had the highest umami intensity. Umami amino acids and nucleotides could increase salty intensity of NaCl at medium and high concentrations. The enzymatic hydrolysate of Antler fungus at higher concentrations could more effectively enhance salty taste of NaCl at lower concentration. This synergistic effect between umami and salty indicates that Antler fungus can potentially be used as an ingredient in low-salt foods.


Assuntos
Chifres de Veado , Glutamato de Sódio , Aminoácidos/farmacologia , Animais , Chifres de Veado/metabolismo , Fungos/metabolismo , Nucleotídeos , Cloreto de Sódio/farmacologia , Glutamato de Sódio/metabolismo , Paladar
9.
Spectrochim Acta A Mol Biomol Spectrosc ; 276: 121223, 2022 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-35429859

RESUMO

Hydrogen sulfide (H2S) has been clearly identified as a hazardous chemical pollutant that seriously affects food safety and human health. In order to develop a rapid, accurate and efficient H2S tracking method, this work propose a strategy based on indicator displacement assays (IDA). A water-soluble histidine-modified perylene diimide fluorescent probe was synthesized by a one-step method, and the probe can form supramolecular aggregates in the presence of Cd2+. There will be a fluorescence transformation of probe, caused by the change of the state of aggregation and adjusted by various concentration of S2-, which can achieve the fluorescence detection of S2-. The limit of detection is as low as 0.41 µmol/L. Particularly worth mentioning is that the probe in this work can be recycled for at least 5 times, which is environmentally friendly and economical. Finally, this method was applied in three kinds of vegetables and monosodium glutamate samples.


Assuntos
Sulfeto de Hidrogênio , Perileno , Corantes Fluorescentes/química , Humanos , Perileno/química , Glutamato de Sódio , Verduras
10.
J Biosci Bioeng ; 133(6): 533-540, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35397991

RESUMO

N-glycosylation of proteins is an important post-translational modification in eukaryotic cells. One of the key modifications in protein N-glycosylation is N-acetylglucosamine (GlcNAc) extension mediated by N-acetylglucosaminyltransferase I (GNTI), which triggers N-glycan maturation from high-mannose-type to hybrid- and complex-type structures in Golgi. However, the temporal contributions of GNTI to GlcNAc extension and the resultant N-glycan structures in insects have not been analyzed. Here, focusing on GlcNAc extension of N-glycan in the silkworm Bombyx mori, we analyzed the temporal N-glycan alterations in the middle silk gland (MSG) and characterized the property of key enzyme for complex-type N-glycan biosynthesis, B. mori GNTI (BmGNTI). N-glycan analysis of N-glycoproteins in the MSG demonstrated that BmGNTI identified and characterized in this study consistently contributed to GlcNAc extension of N-glycans, which led to the accumulation of GlcNAc-extended N-glycans as predominant structures throughout the MSG development. The expression profile of GlcNAc extension-related genes revealed that the enzymes contributing to the hydrolysis of GlcNAc showed stage-specific expressions, thereby resulting in accumulations of the end product N-glycans of the enzyme. These results lead to the speculation that not BmGNTI but rather glycosylhydrolases critically influenced the structural formations and the changes in the ratio of N-glycans with GlcNAc residue(s) in MSG.


Assuntos
Bombyx , Acetilglucosamina/metabolismo , Animais , Bombyx/genética , Polissacarídeos/metabolismo , Seda , Glutamato de Sódio
11.
Exp Physiol ; 107(6): 575-588, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35396880

RESUMO

NEW FINDINGS: What is the central question of this study? Can an anaemic state modify adiposity and metabolic parameters in hypothalamic obese rats? What is the main finding and its importance? Hypothalamic obese rats do not display iron deficiency. However, the pharmacological induction of anaemia in hypothalamic obese rats resulted in reduced adiposity, characterized by a decrease in subcutaneous white and brown adipose tissue depots. These findings suggest that iron imbalance in obesity may elevate lipolysis. ABSTRACT: Iron imbalance is frequent in obesity. Herein, we evaluated the impact of anaemia induced by phenylhydrazine on adiposity and metabolic state of hypothalamic obese rats. Hypothalamic obesity was induced by high doses of monosodium glutamate (MSG; 4 g/kg) administered to neonatal male rats (n = 20). Controls (CTL; non-obese rats) received equimolar saline (n = 20). Rats were weaned at 21 days of life. At 70 days, half of the rats received three intraperitoneal doses of phenylhydrazine (PHZ; 40 mg/kg/dose) or saline solution. Body weight and food intake were followed for 4 weeks after PHZ administration. At 92 days, rats were killed and blood was collected for microcapillary haematocrit (Hct) analysis and plasma quantification of glucose, triglycerides, total cholesterol and iron levels. The liver, the spleen, and the white (WAT) and brown (BAT) adipose tissues were excised, weighed and used for histology. MSG-treated rats developed obesity, hypertriglyceridaemia and insulin resistance, compared to CTL rats, without changes in iron levels and Hct. PHZ administration reduced plasma iron levels and promoted similar tissue injuries in the spleen and liver from MSG and CTL rats. However, in MSG-treated rats, PHZ decreased fasting glucose levels and Hct, as well as diminishing the subcutaneous WAT and BAT mass. Although MSG-obesity does not affect plasma iron levels and Hct by itself, PHZ-induced anaemia associated with obesity induces a marked drop in subcutaneous WAT and BAT mass, suggesting that iron imbalance may lead to increased lipolytic responses in obese rats, compared to lean rats.


Assuntos
Tecido Adiposo Marrom , Anemia , Tecido Adiposo/metabolismo , Tecido Adiposo Marrom/metabolismo , Anemia/induzido quimicamente , Anemia/metabolismo , Animais , Glucose/metabolismo , Ferro , Masculino , Obesidade/metabolismo , Fenil-Hidrazinas/efeitos adversos , Fenil-Hidrazinas/metabolismo , Ratos , Glutamato de Sódio
12.
Mol Neurobiol ; 59(6): 3755-3766, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35381888

RESUMO

Circumventricular organs (CVOs), including the mediobasal hypothalamus (MBH), have an incomplete blood-brain barrier (BBB). In this study, we determined if the BBB function in the MBH is modulated by the gut microbiota or by the Toll-like receptor (TLR) adapter proteins TRIF or MyD88 signaling. By injecting mice with Evans blue, a marker for BBB permeability, we show that germ-free (GF) and conventionally raised (CONV-R) mice did not differ in the number of Evans blue-positive cells in MBH. Acute modulation of the gut microbiota did not change the number of Evans blue-positive cells. In contrast, CONV-R Myd88-/- and Trif-/- mice had a reduced number of cells in direct contact to the circulation compared to wildtype (WT) mice. This was accompanied by increased tight junction proteins in the blood vessels in Myd88-/- mice. To further characterize the BBB function, we injected WT and Myd88 -/- CONV-R mice as well as WT GF mice with monosodium glutamate (MSG), a neurotoxin that does not cross the BBB. While MSG caused vast cell death in the MBH in CONV-R and GF WT mice, Myd88 -/- mice were protected from such cell death suggesting that fewer cells are exposed to the neurotoxin in the Myd88 -/- mice. Taken together, our results suggest that MyD88 deficiency, but not gut microbiota depletion, is sufficient to modulate the BBB function in the MBH.


Assuntos
Barreira Hematoencefálica , Microbioma Gastrointestinal , Hipotálamo , Fator 88 de Diferenciação Mieloide , Proteínas Adaptadoras de Transporte Vesicular/metabolismo , Animais , Barreira Hematoencefálica/metabolismo , Azul Evans , Hipotálamo/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fator 88 de Diferenciação Mieloide/metabolismo , Neurotoxinas/toxicidade , Glutamato de Sódio/toxicidade
13.
Amino Acids ; 54(7): 1055-1068, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35292855

RESUMO

This study was conducted to test the hypothesis that increasing dietary content of glutamate through addition of monosodium glutamate (MSG) enhances milk production by lactating sows and the growth of their offspring. Thirty multiparous sows (Landrace × Large White) were assigned randomly into one of three dietary groups: control (a corn- and soybean meal-based diet), the basal diet + 1% MSG, and the basal diet + 2% MSG. Diets were made isonitrogenous by the addition of appropriate amounts of L-alanine. Lactating sows had free access to drinking water and were fed twice daily their respective diets. The number of live-born piglets was standardized to 9 per sow at day 0 of lactation (the day of farrowing). On days 3, 15, and 29 of lactation, body weight and milk consumption of piglets were measured, and blood samples obtained from sows and piglets at 2 h and 1 h after feeding, respectively. Feed intake of sows did not differ (P > 0.05) among the three groups of sows. Concentrations of aspartate, glutamine, citrulline, arginine, tryptophan, proline, branched-chain amino acids, and glutamate were greater (P < 0.05) in the plasma of MSG-supplemented sows and their piglets than for controls. When compared with the control, dietary supplementation with 1-2% MSG increased (P < 0.05): concentrations of many free amino acids (including glutamate plus glutamine) and all protein-bound amino acids in milk; the milk intake of piglets by 14-25%; and daily weight gains of piglets by 23-44%. These results indicate that dietary supplementation with 1-2% MSG to lactating sows enhances milk production to support the growth of sow-reared piglets.


Assuntos
Lactação , Leite , Aminoácidos/metabolismo , Ração Animal/análise , Animais , Dieta/veterinária , Suplementos Nutricionais , Feminino , Glutamina/metabolismo , Leite/química , Glutamato de Sódio/análise , Glutamato de Sódio/metabolismo , Glutamato de Sódio/farmacologia , Suínos
14.
Int J Dev Neurosci ; 82(4): 331-338, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35338672

RESUMO

Present investigation evaluates the protective effect of Celastrus paniculatus (CP) on the cognitive function in neuronal injured mice. Neuronal injury was induced by oral administration of monosodium glutamate (MSG) at a dose of 1.66 g/kg/day for 30 days. Mice in the CP-treated group receives CP 30 mg/kg ip and CP + GGA-treated group received CP 30 mg/kg ip and glutamic acid (GGA, 1.5 mg/kg, ip) 30 min prior to the administration of MSG for 30 days. Assessment of cognitive function was done using Morris water maze. Level of inflammatory cytokines and production of reactive oxygen species (ROS) was estimated in the brain tissue of brain-injured mice. Moreover, intracellular concentration of Ca+ ion was estimated in the brain tissue and expression of Bcl-2, Bax, and caspase-3 protein was estimated in the brain tissue by western blot assay. Cognitive function was attenuated in CP-treated glutamate-injured mice. Data of the study suggest that treatment with CP reduces the level of inflammatory cytokines and production of ROS in the brain tissue compared to negative control group. There was reduction in the concentration of Ca+ ion in the neuronal cells in CP-treated group than negative control group of mice. Treatment with CP ameliorates the expression of Bax, Bcl-2, and caspase-3 in the brain tissue of glutamate-induced brain-injured mice. In conclusion, data of the study suggest that treatment with CP attenuates the cognitive function and neuronal apoptosis in glutamate-induced neuronal injury by reducing the concentration of intracellular Ca+ ion.


Assuntos
Celastrus , Animais , Apoptose , Encéfalo/metabolismo , Caspase 3/metabolismo , Celastrus/metabolismo , Cognição , Citocinas/metabolismo , Glutamatos/metabolismo , Camundongos , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Espécies Reativas de Oxigênio/metabolismo , Glutamato de Sódio , Proteína X Associada a bcl-2/metabolismo
15.
Nutrients ; 14(5)2022 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-35268017

RESUMO

OBJECTIVE: The aim of this study was to perform analysis of sensitivity to sweet, salty, and umami tastes based on three measurement methods and of the hedonic perception of taste sensations in adolescent females with anorexia nervosa (AN). The aim of the research was to confirm the results of other authors in terms of the perception of sweet and salty taste in patients with AN, and then develop knowledge about the perception of umami taste, which is still insufficiently studied. METHOD: A total of 110 females with an age ranging from 13 to 19 years, including 50 newly diagnosed patients with a restrictive subtype of AN and 60 healthy controls participated in gustatory research involving analyses of taste perception (recognition thresholds, ability to identify the taste correctly, taste intensity, and hedonic response) applying the sip and spit method. RESULTS: Females with AN showed reduced sensitivity to salty taste and increased sensitivity to umami taste and, more often than healthy controls, wrongly classified the taste of solutions with a low sucrose concentration. Patients with AN assessed the sodium chloride and monosodium glutamate tastes less negatively than did control participants, and they did not show differences in their hedonic assessment of sucrose. CONCLUSIONS: The taste sensitivity alterations in females with AN demonstrated in this paper do not entail decreased hedonic assessment of taste experiences. Based on our results, we cannot consider the observed variation in taste sensitivity in patients with AN to be a factor that increases their negative attitude toward food consumption.


Assuntos
Anorexia Nervosa , Paladar , Adolescente , Adulto , Feminino , Humanos , Glutamato de Sódio/farmacologia , Sacarose/farmacologia , Paladar/fisiologia , Percepção Gustatória/fisiologia , Adulto Jovem
16.
J Food Sci ; 87(4): 1449-1465, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35301715

RESUMO

Understanding taste is key for optimizing the palatability of seaweeds and other non-animal-based foods rich in protein. The lingual papillae in the mouth hold taste buds with taste receptors for the five gustatory taste qualities. Each taste bud contains three distinct cell types, of which Type II cells carry various G protein-coupled receptors that can detect sweet, bitter, or umami tastants, while type III cells detect sour, and likely salty stimuli. Upon ligand binding, receptor-linked intracellular heterotrimeric G proteins initiate a cascade of downstream events which activate the afferent nerve fibers for taste perception in the brain. The taste of amino acids depends on the hydrophobicity, size, charge, isoelectric point, chirality of the alpha carbon, and the functional groups on their side chains. The principal umami ingredient monosodium l-glutamate, broadly known as MSG, loses umami taste upon acetylation, esterification, or methylation, but is able to form flat configurations that bind well to the umami taste receptor. Ribonucleotides such as guanosine monophosphate and inosine monophosphate strongly enhance umami taste when l-glutamate is present. Ribonucleotides bind to the outer section of the venus flytrap domain of the receptor dimer and stabilize the closed conformation. Concentrations of glutamate, aspartate, arginate, and other compounds in food products may enhance saltiness and overall flavor. Umami ingredients may help to reduce the consumption of salts and fats in the general population and increase food consumption in the elderly.


Assuntos
Papilas Gustativas , Percepção Gustatória , Idoso , Humanos , Inosina Monofosfato/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Glutamato de Sódio/metabolismo , Paladar/fisiologia , Papilas Gustativas/metabolismo , Percepção Gustatória/fisiologia
17.
Chem Senses ; 472022 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-35255134

RESUMO

The prototypical stimuli for umami taste is monosodium glutamate (MSG), which is the sodium salt form of glutamic acid. A proportion of the population has a reduced or complete inability to taste l-glutamate independent to the sodium ion. To determine individuals' umami discrimination status, many studies use a series of triangle tests containing isomolar (29 mM) sodium chloride (NaCl) and MSG, requiring participants to correctly identify the odd sample. Across studies, inconsistent categorization criteria have been applied. The aim of this study was to determine the optimal classification criterion based on the number of tests assessed to ascertain an individual's ability to discriminate between MSG and NaCl. Thirty-eight participants attended 3 taste assessment sessions, each involving 24 triangle tests (2 blocks of 12 tests) containing 29 mM NaCl and 29 mM MSG, detection and recognition threshold were measured for MSG, monopotassium glutamate (MPG), and sweet (sucrose) tastes. There was no learning, or fatigue trend over n = 24 (P = 0.228), and n = 12 (P = 0.940) triangle tests across each testing session. Twenty-four triangle tests produced the most consistent categorization of tasters across sessions (68.4%). The test-retest correlation across each testing session was highest for n = 24 triangle tests (ICC = 0.50), in comparison to 12 (ICC = 0.37). Overall, conducting n = 24 compared with n = 12 triangle tests provided the optimal classification to determine an individual's ability to discriminate l-glutamate from NaCl and thus their umami discrimination status, based on the number of tests assessed in this study.


Assuntos
Glutamato de Sódio , Papilas Gustativas , Humanos , Sódio , Cloreto de Sódio/farmacologia , Glutamato de Sódio/farmacologia , Paladar
18.
Environ Sci Pollut Res Int ; 29(30): 45338-45348, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35143005

RESUMO

Monosodium glutamate (MSG) is a flavor enhancer commonly used in modern nutrition. In this study, it was aimed to determine the effect of in ovo administered MSG on the embryonic development of thymus, bursa of Fabricius, and percentages of alpha-naphthyl acetate esterase (ANAE) positive lymphocyte by using histological, histometrical, and enzyme histochemical methods in chickens. For this purpose, 410 fertile eggs were used. The eggs were then divided into five groups: group 1 (control group, n = 40 eggs), group 2 (distilled water-injected group, n = 62 eggs), group 3 (0.12 mg/g egg MSG-injected group, n = 80 eggs), group 4 (0.6 mg/g egg MSG-injected group, n = 90 eggs), and group 5 (1.2 mg/g egg MSG-injected group, n = 138 eggs), and injections were performed via the egg yolk. On the 18th and 21st days of the incubation, the eggs were randomly opened from each group until six live embryos were obtained. The embryos of each group were sacrificed by decapitation, and blood, thymus, and bursa of Fabricius tissue samples were taken from the obtained embryos. The MSG-treated groups were found to be retarded embryonic development of thymus and bursa of Fabricius tissue compared to the control and distilled water groups. MSG treatment also resulted in reduced lymphoid follicles count and follicle diameters in bursa of Fabricius (P < 0.05). The percentage of peripheral blood ANAE positive lymphocytes was significantly lower in the MSG-treated groups than in the control and distilled water groups (P < 0.05). In conclusion, it has been found that in ovo administered MSG can adversely affect the embryonic development of thymus and bursa of Fabricius and decrease percentage of ANAE positive lymphocyte.


Assuntos
Galinhas , Thymus (Planta) , Animais , Bolsa de Fabricius , Desenvolvimento Embrionário , Linfócitos , Naftol AS D Esterase/farmacologia , Glutamato de Sódio/farmacologia , Timo , Água
19.
J Dairy Sci ; 105(5): 3883-3895, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35221058

RESUMO

Previous research has showed that nonproteolytic Levilactobacillus brevis 145 (L) in coculture with Streptococcus thermophilus 1275 (S), not Lactobacillus delbrueckii ssp. bulgaricus (Lbu), was able to produce γ-aminobutyric acid (GABA) during milk fermentation in the presence of monosodium glutamate (MSG). It was assumed that differences of casein hydrolysis patterns between Strep. thermophilus 1275 and L. bulgaricus caused the phenomenon. Moreover, the GABA content was low and residual MSG was high in SL-fermented milk. In our research, comparison of peptide profiles determined by liquid chromatography/tandem mass spectrometry showed that αS2-casein, ß-casein, and κ-casein degradation by L. bulgaricus and Strep. thermophilus varied. Importantly, the peptide number in the L and Lbu coculture group increased compared with the Lbu monoculture group, whereas the peptide number in the SL coculture group decreased in comparison with S monoculture group, suggesting that L. bulgaricus was not able to provide peptides for the growth of Lb. brevis 145. Furthermore, we found that after supplementation with cysteine (50 mg/L) during milk fermentation by SL, 10 g/L MSG was converted into 4.8 g/L GABA with a minimum level of residual MSG, viable cell counts of Lb. brevis and lactic acid production were increased, and the casein hydrolysis pattern was not influenced. Moreover, sulfhydryl group-containing chemicals including cystine, reduced glutathione, and oxidized glutathione showed effects similar to that of cysteine in improving GABA production. Finally, when L. bulgaricus YIB2 was combined with SL, supplementation of cysteine was also able to significantly improve GABA production.


Assuntos
Lactobacillus delbrueckii , Streptococcus thermophilus , Animais , Caseínas/metabolismo , Técnicas de Cocultura/veterinária , Cisteína , Fermentação , Lactobacillus delbrueckii/metabolismo , Peptídeos/metabolismo , Glutamato de Sódio/metabolismo , Streptococcus thermophilus/metabolismo , Iogurte , Ácido gama-Aminobutírico
20.
J Food Biochem ; 46(5): e14092, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35092065

RESUMO

In the present socioeconomic era, people are consuming ready-made fast-food regularly with minimal physical exercise. Food processors use monosodium glutamate, saturated fatty acids, and hydrogenated fats to prepare flavor-enhancing high-lipid diet (FHD), which cause oxidative damage to different experimental animals and humans through the generation of reactive oxygen species. This study aimed to assess the protective effects of Coccinia grandis against hepatocellular damage caused by FHD. Rats were fed with FHD (prepared with monosodium glutamate in combination with HLD) with or without ethanol extract of Coccinia grandis leaves (EECGL) for 28 days to measure hematological, biochemical, inflammatory, apoptotic biomarkers, cytomorphological changes, and apoptosis of liver, if any. The results indicate that FHD causes hepatic damage by modifying hematological and biochemical parameters, followed by the activation of NF-kB and caspase pathways. Moreover, FHD altered the Bcl2/Bax ratio, nuclear condensation, shrinkage, and fragmentation of hepatocytes, leading to inflammation and apoptosis. On the other hand, EECGL appears to play a significant role in preventing FHD-induced hepatocellular damage via regulating inflammatory and apoptotic factors. In this regard, EECGL might be a useful dietary supplement to reduce the negative impact of a frequent consumption of FHD as part of fast-food. PRACTICAL APPLICATIONS: Fast food is believed to be a flavor-enhanced high-lipid diet, since its delectable taste stimulates the hunger. Eventually, such a diet functions as a silent assassin for many body systems. The current study primarily focused on the negative health effects of commonly used flavoring agents in high-lipid diets, which presents a warning against the choice of meals, particularly food additive mixed diets, and issues an alarming signal to society concerning the use of such combinations in regular diets. Furthermore, this study recommends using Coccinia grandis, which has a variety of bioactive phytoconstituents, as a dietary supplement to counteract the flavor-enhancing high-lipid diet-induced anomalous condition.


Assuntos
Carcinoma Hepatocelular , Cucurbitaceae , Neoplasias Hepáticas , Animais , Apoptose , Biomarcadores , Dieta , Humanos , Inflamação/tratamento farmacológico , Inflamação/etiologia , Inflamação/metabolismo , Lipídeos , Ratos , Glutamato de Sódio
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