Γ-aminobutyric Acid Content Research Articles

Transcriptome and targeted metabolome analysis of lipid profiles, nutrients compositions and volatile compounds in longissimus dorsi of different pig breeds.

Improving meat quality is important for commercial production and breeding. The molecular mechanism of intramuscular fat (IMF) deposition and meat characteristics remain further study. This study aimed to study the mechanism of IMF deposition and meat characteristics including redox potential, nutrients compositions and volatile compounds in longissimus dorsi (LD) by comparing with different pig breeds including Shanghai white (SW), Duroc x (Landrace Yorkshire) (DLY) and Laiwu (LW) pigs. Results showed that the contents of IMF, triglyceride (TG), total cholesterol (TC), and redox potential parameters were lower, while the content of MDA and activity of lactate dehydrogenase (LDH) were higher in LD of SW pigs compared with LW pigs (p<0.05). No differences were observed about these parameters between SW and DLY pigs. Also, the contents of medium-long chain fatty acids and γ-aminobutyric acid (GABA) were higher, while Asp was lower in LD of SW pigs compared with LW pigs (p<0.05). Volatile compounds results showed that 6 ketones, 4 alkenes, 11 alkanes, 2 aldehydes, 1 alcohol were increased and cholesterol was decreased in SW pigs compared with LW pigs. Transcriptome results showed that differential expressed genes involved in lipid synthesis, metabolism and transport in LD between SW and LW pigs, which were further verified by qPCR. Spearman correlation showed that HSL and Nedd4 were positively related to contents of TG and IMF, while negatively related to volatile compounds and fatty acids (p<0.05). Plin3 and Mgll were negatively related to contents of TG, IMF and cholesterol, while positively related to MDA, LDH, and volatile compounds (p<0.05). PPARA was negatively related to contents of TC and IMF, and activity of SOD, while positively related to volatile compounds (p<0.05). Our study provided new insights into potential mechanisms of IMF deposition, nutrients composition and volatile compounds of muscular tissues of different pig breeds.

Reduction of soybean globulin antigen by soybean protein isolate/γ-aminobutyric acid complexes: Effect of the different concentrations of γ-aminobutyric acid on the protein modification, antigen levels, and foaming properties

Soybean flour has received increasing attention because of its unique nutritional properties. However, potential allergies to soy protein limit its application. This study aims to investigate the impact of various concentrations of γ-aminobutyric acid (GABA) on the secondary structure, foaming properties, and antigenicity of soybean protein obtained from soybean flour under thermal sterilisation. GABA increased the content of α-helix, reduced β-turn and random coil in soybean protein. The results indicated that after heating treatment, the concentration of GABA significantly affects the spatial conformation of soybean protein isolates (SPI). When the concentration of GABA was 0.40% (w/v), the particle size, zeta potential, and surface hydrophobicity of the SPI were the lowest, whereas the disulfide bond content was the highest. Multi-spectral technologies indicated that adding 0.40% GABA could assemble the system in a relatively stable manner. Moreover, the rigid structure of the protein was destroyed. This structural change significantly reduced the foaming and allergy of the protein. Adding 0.40% GABA could reduce the β-conglycinin antigen concentration from 24.26 mg/mL to 4.43 mg/mL. This study provides new insights into the production of new low-allergenic soybean flour. Additionally, it offers an assurance for the safe consumption of soybeans by individuals with allergies.

Regulation of Glutamate and γ-Aminobutyric Acid Receptors in Rats with Depression by Sniffing the Essential Oil of Citrus × aurantium L. [Rutaceae

Background Modern research has proved that the volatile oil (VO) of Citrus × aurantium L. [Rutaceae] has the effect of treating depression, but the mechanism of treating depression by sniffing has not been studied. Purpose To study the mechanism of VO on depression. Methods Part I: Except for the blank group, the sniffing group and nasal drip group were continuously administered for 7 days to investigate the optimal administration method. Part II: Except for the blank group, the model, positive group, high, medium, and low dose group of VO were established by chronic unpredictable stress test. The VO was given on the 7th day of modeling for 17 consecutive days. The expression of neurotransmitters and receptors in the brain was determined. The medicinal ingredients in rat brain tissue and blood were detected by gas chromatography–mass spectrometry (GC–MS). Results Compared with nasal drip, sniffing administration has less irritation to the nasal mucosa. The VO could reduce the forced swimming immobility time, adjust the activity state, increase the content of γ-aminobutyric acid (GABA), reduce the content of glutamate, and upregulate the expression of GABAα1, GABAγ2, and their mRNA. The main pharmaceutical component is d-limonene. Conclusion d-limonene in VO upregulates GABAα1, GABAγ2 expression to treat depression.

Enhancement of γ-aminobutyric acid content in Huangjiu through rice bran fermentation and its impact on the volatile organic compounds

Rice bran has high glutamic acid decarboxylase (GAD) activity and can be used to enrich and produce γ-aminobutyric acid (GABA). Glutinous rice was used as raw material to brew Huangjiu by liquefaction fermentation. Rice bran extract was added at different fermentation stages, then the content of GABA and basic physicochemical properties were tested, the changes of flavor substances and volatile organic compounds (VOCs) were observed in Huangjiu. The results showed the addition of concentrated GABA-enriched rice bran extract during the post-fermentation stage significantly increases the GABA content in Huangjiu. When the amount of rice bran used is 50 g, the GABA content in the Huangjiu can reach 592.44 mg/L after fermentation. The total sugar and pH of Huangjiu fermented with rice bran extract were higher than the control group, and the total acid and non-sugar solids were lower than the control group. Electronic tongue analysis showed that the addition of rice bran extract would affect the sourness, umami and saltiness taste of Huangjiu. Gas Chromatography-Ion Mobility Spectrometry (GC-IMS) analysis of Huangjiu made by adding rice bran extract at the post-fermentation stage showed increased isoamyl acetate, 2-heptanol, and other substances in comparison with the control group. The results of the study provide a cost-effective and rapid method for increasing the GABA content in Huangjiu. It also offers a theoretical basis and scientific guidance for the production of health-oriented Huangjiu.

Study of the relationship among biomarkers, cell and tissue of glioma through Raman spectroscopy

Glioma is the most common brain tumors with high mortality and recurrence rates. Currently, the diagnosis methods for glioma are mainly based on tissue level, cellular level and biomarker level. In this paper, the characteristics of biomarkers (γ-aminobutyric acid and matrix mtalloproteinses-2), U87MG glioma cell and tissue were studied based on Raman spectroscopy, respectively. The results showed that the γ-aminobutyric acid concentration exhibited a linear relation with the intensity of characteristic peaks in 800–1600 cm−1 region, whereas the spectral baseline increased with the increasing of sample concentration in 200–700 cm−1 region. The Raman characteristics of matrix mtalloproteinses-2 in 20–1800 cm−1 region was investigated. Especially, it is demonstrated that the matrix mtalloproteinses-2 showed sixteen low-wavenumber Raman peaks in the range of 20–300 cm−1. Moreover, the U87MG glioma cell showed seven different Raman characteristic peaks in 600–1800 cm−1 region. Compared with the normal tissue, the Raman intensity of tumor tissue showed apparent intensity differences in 300–1800 cm−1, where the intensity changes of these Raman peaks were related to the reducing of the lipid metabolic pathways, and increase of the RNA in tumor tissue region. Furthermore, it is found that the Raman spectra of U87MG glioma cell and tumor tissue had corresponding peaks in the Raman spectra of the liquid γ-aminobutyric acid and matrix mtalloproteinses-2. It is suggested that the γ-aminobutyric acid and matrix mtalloproteinses-2 contributed to the formation and growth of glioma cell and tissue. Thus, Raman spectroscopy not only can diagnose glioma at the biomarkers, cellular and tissue level, but also analyze the relationship among the three. Furthermore, the results provided a physical marker for the detection of glioma in clinically.

Non-Targeted Metabolomics Analysis of γ-Aminobutyric Acid Enrichment in Germinated Maize Induced by Pulsed Light.

Pulsed light is an emerging technique in plant physiology recognized for its ability to enhance germination and accumulate γ-aminobutyric acid in maize. Pulsed light involves exposing plants to brief, high-intensity bursts of light, which can enhance photosynthesis, improve growth, and increase resistance to environmental stresses. Despite its promising potential, the specific metabolic changes leading to γ-aminobutyric acid enrichment in maize induced by pulsed light are not fully understood. This study addresses this gap by quantifying key nutrients and γ-aminobutyric acid-related compounds during maize germination and investigating the underlying mechanisms using non-targeted metabolomics. Our findings indicate that pulsed light significantly promotes maize germination and accelerates the hydrolysis of proteins, sugars, and lipids. This acceleration is likely due to the activation of enzymes involved in these metabolic pathways. Additionally, pulsed light markedly increases the content of glutamic acid and the activity of glutamate decarboxylase, which are crucial for γ-aminobutyric acid synthesis. Moreover, pulsed light significantly reduces the activity of γ-aminobutyric transaminase, thereby inhibiting γ-aminobutyric acid decomposition and resulting in a substantial increase in γ-aminobutyric acid content, with a 27.20% increase observed in germinated maize following pulsed light treatment. Metabolomic analysis further revealed enrichment of metabolic pathways associated with γ-aminobutyric acid, including amino acid metabolism, carbohydrate metabolism, plant hormone signal transduction, energy metabolism, pyrimidine metabolism, and ABC transporters. In conclusion, pulsed light is a robust and efficient method for producing sprouted maize with a high γ-aminobutyric acid content. This technique provides a novel approach for developing sprouted cereal foods with enhanced nutritional profiles, leveraging the physiological benefits of γ-aminobutyric acid, which include stress alleviation and potential health benefits for humans.

Influence of germination time on free amino acids, phenolic compounds and γ-aminobutyric acid in pigeon pea (Cajanus cajan (L.) Huth) seeds

This research studied the influence of phytochemical compounds on the germination time of pigeon pea (Cajanus cajan (L.) Huth). Over the 72 hours germination period, the contents of total and most individual free amino acids, particularly histidine, showed substantial increases. The content of γ-aminobutyric acid (GABA) was also greatly increased, from 0.24 µg/g to 2.7 µg/g, representing a nearly ninefold increase. The total phenolic content (TPC) and total flavonoid content (TFC) were positively related with germination time, with TPC highest at 62.49 mg GAE/100 g DW at 72 h, and TFC increased from 18.87 mg RE/100 g DW to 30.05 mg RE/100g.DW at 72 hours. The contents of individual phenolic acids and flavonoids, such as, protocatechuic acid, p-coumaric acid, ferulic acid and rutin, experienced noticeable increases. However, vanillic and catechin were only detectable at 72 hours, respectively. Antioxidant capacity measured by DPPH and FRAP assays increased from 102.30 to 128.95 mgTE/100g DW and 694.13 to 836.93 mg FeSO4/100g DW mmol/g, respectively, and therefore highlighting the enhanced antioxidant potential of germinated pigeon pea. The results from Fourier-transform infrared spectroscopy (FTIR) supported these findings. The study emphasizes the potential of germination to enhance the phytochemical compounds of pigeon pea seeds.

Differences in cooking taste and physicochemical properties between compound nutritional rice and common rice.

In this study, it was compared the physicochemical properties and cooking taste quality between four different types of compound nutritional rice (rice flour with the addition of other coarse grains, legumes, potatoes, and other powders, extruded as artificial rice grains) and common rice. We found that the protein and apparent amylose contents of compound nutritional rice were higher than that of common rice, up to 9.775% and 19.45% respectively. The γ-aminobutyric acid (GABA) and resistant starch contents were much lower than in common rice, and the dietary fiber content did not differ from that in common rice. The results of Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis revealed that the starch properties and structure of the compound nutritional rice changed due to high temperature and high pressure processing. In particular, the crystalline structures of starch became V-shaped. In addition, the results of artificial tasting and tasting meter showed that the taste of compound nutritional rice was generally inferior to that of common rice. In summary, compound nutritional rice had problems such as nutritional imbalance and poor taste. There was still a lot of room for improving the taste quality of compound nutritional rice. Therefore, the future development of compound nutritional rice should focus on both nutritional balance and taste improvement. The results of this paper also provided a certain theoretical basis for this.

The functional and nutritional properties of a novel Monascus fermented rice rich in resistant starch

Rice high in resistant starch (RS) showed great benefits in preventing diabetes. Red mold rice (RMR) is a traditionally functional food in China, preparing RMR with high-RS rice might produce a novel RMR with better nutrients and promote the utilization of high-RS rice in the food industry. R4 with the highest RS content was the most prone to be fermented by Monascus. After fermentation, the total starch and protein contents were significantly decreased, while the RS, lipid, free glucan, total free amino acids (FAAs), and γ-aminobutyric acid (GABA) contents were remarkably increased. Concurrently, the phenolic content and antioxidation activity were enhanced greatly. The individual phenolic acids such as ferulic acid showed significantly positive correlations with the antioxidant activity. Besides the abundant lipids, FAAs, GABA, and strong antioxidant capacity, fermented R4 had the highest ferulic acid content. This study provided alternatives for producing novel RMR and widened applications of high-RS rice in innovative functional foods.

The Anti-Inflammatory Effects and Mechanism of the Submerged Culture of Ophiocordyceps sinensis and Its Possible Active Compounds.

The pharmacological effects of the fruiting body of Ophiocordyceps sinensis (O. sinensis) such as antioxidant, anti-virus, and immunomodulatory activities have already been described, whereas the anti-inflammatory effects and active components of the submerged culture of O. sinesis (SCOS) still need to be further verified. This study aimed to investigate the active compounds in the fermented liquid (FLOS), hot water (WEOS), and 50-95% (EEOS-50, EEOS-95) ethanol extracts of SCOS and their anti-inflammatory effects and potential mechanisms in lipopolysaccharide (LPS)-stimulated microglial BV2 cells. The results demonstrated that all of the SCOS extracts could inhibit NO production in BV2 cells. EEOS-95 exhibited the strongest inhibitory effects (71% inhibitory ability at 500 µg/mL), and its ergosterol, γ-aminobutyric acid (GABA), total phenolic, and total flavonoid contents were significantly higher than those of the other extracts (18.60, 18.60, 2.28, and 2.14 mg/g, p < 0.05, respectively). EEOS-95 also has a strong inhibitory ability against IL-6, IL-1β, and TNF-α with an IC50 of 617, 277, and 507 µg/mL, respectively, which is higher than that of 1 mM melatonin. The anti-inflammatory mechanism of EEOS-95 seems to be associated with the up-regulation of PPAR-γ/Nrf-2/HO-1 antioxidant-related expression and the down-regulation of NF-κB/COX-2/iNOS pro-inflammatory expression signaling. In summary, we demonstrated that EEOS-95 exhibits neuroinflammation-mediated neurodegenerative disorder activities in LPS-induced inflammation in brain microglial cells.

Analyzing the Effects of Rapid and Natural Cooling Techniques on the Quality of Hand-Shaken Green Tea Beverages.

This study compared the quality of hand-shaken green tea prepared through rapid and natural cooling methods. Cooling is crucial in preserving green tea's flavor, aroma, and nutritional components. In the rapid cooling method, green tea is freshly brewed at an initial temperature of 95 °C for 25 min, and then rapidly cooled to 18 °C for 25 min. Conversely, the natural cooling method involves brewing tea at the same initial temperature and time, but allowing it to cool gradually to 30 °C over approximately 4-5 h at room temperature. This study's findings indicate that the rapid cooling method produced green tea with a more vibrant color and improved clarity versus the natural cooling method. Sensory analysis revealed that the taste and aroma of the hand-shaken green tea prepared using rapid cooling were perceived to be more refreshing and invigorating. However, the natural cooling method preserved a higher level of chemical components, including individual catechin caffeine, total polyphenol, soluble solids, reducing sugar, and total tannins. The essential amino acid content of the rapidly and naturally cooled green tea infusions was 6.85 and 13.55 μg/mL, respectively. The γ-Aminobutyric acid (GABA) content was 439.82 and 457.31 μg/mL, respectively. This study's findings suggest that rapid cooling during the preparation of hand-shaken green tea enhances its overall quality. The vibrant color, improved clarity, refreshing taste, and invigorating aroma make it a preferable choice for tea enthusiasts who seek an enhanced sensory experience and excellent quality.

The neurochemistry of learning-driven sensory eye dominance plasticity

Abstract Sensory eye dominance (SED) refers to a functional asymmetry of the two eyes that is thought to result from the visual cortex assigning uneven weighting to the two eyes’ data. Dichoptic perceptual training has been shown to improve (reduce) SED in visually normal individuals, with behavioral improvements accompanied by alterations of neural responses in the primary visual cortex. The mechanisms underlying these learning-driven neural changes are not well understood. Here, using magnetic resonance spectroscopy, we determined how inhibitory mechanisms in the early visual cortex (EVC) govern SED plasticity by measuring γ-aminobutyric acid (GABA) concentration changes before and after perceptual training. Fifty normal-sighted observers were trained on a dichoptic or binocular variant of a signal-in-noise (left–right) motion discrimination task. We observed significant shifts in SED following dichoptic (but not binocular) training. Before training, both groups exhibited lower GABA concentrations in the EVC when signals were presented to the dominant eye. Only after dichoptic training, GABA concentrations in the EVC increased during presentations of signals to the dominant eye and decreased during presentations of signals to the non-dominant eye. Our data suggest that dichoptic training drives changes in SED by promoting a rebalancing of interocular inhibition in the EVC.

Effects of anaerobic treatment on the non-volatile components and angiotensin-converting enzyme (ACE) inhibitory activity of purple-colored leaf tea

This study investigated the effect of anaerobic treatment on the non-volatile components and angiotensin-converting enzyme (ACE) inhibitory activity in purple-colored leaf tea. Results showed that after 8 h of anaerobic treatment, the γ-aminobutyric acid (GABA) content significantly increased from 0.02 mg/g to 1.72 mg/g (p < 0.05), while lactic acid content gradually rose from non-detectable levels to 3.56 mg/g. Notably, certain flavonols like quercetin and myricetin exhibited significant increments, whereas the total anthocyanins (1.01 mg/g) and epigallocatechin-3-(3''-O-methyl) gallate (13.47 mg/g) contents remained almost unchanged. Furthermore, the ACE inhibition rate of purple-colored leaf tea increased significantly from 42.16% to 49.20% (p < 0.05) at a concentration of 2 mg/mL. Moreover, galloylated catechins showed stronger ACE inhibitory activity than non-galloylated catechins in both in vitro ACE inhibitory activity and molecular docking analysis. These findings might contribute to the development of special purple-colored leaf tea products with potential therapy for hypertension.

Impact of Germination on the Edible Quality and Nutritional Properties of Brown Rice Noodles.

Brown rice noodles are increasingly favored by consumers for their health benefits; however, their development is hindered by their poor edible qualities. The effect of germination on the cooking, textural, organoleptic and nutritional qualities of brown rice pasta was investigated. In comparison to ungerminated brown rice noodles, germination resulted in a shorter cooking time, reduced cooking losses, and decreased hardness and adhesion of noodles as well as reduced bitter taste. These changes can be attributed to germination altering the basic composition of brown rice. Meanwhile, the contents of γ-aminobutyric acid, free phenolic acid, and bound phenolic acid increased by 53.43%, 21.71%, and 7.14%, respectively, while the content of resistant starch de-creased by 21.55%. Sprouting is a promising strategy for improving the edible quality and nutritional properties of brown rice noodles.

Paeonol and glycyrrhizic acid in combination ameliorate the recurrent nitroglycerin-induced migraine-like phenotype in rats by regulating the GABBR2/TRPM8/PRKACA/TRPV1 pathway

Ethnopharmacological relevancePaeonol (PAE) and glycyrrhizic acid (GLY) are predominate components of 14 blood-entering ones of Piantongtang No. 1, which is a traditional Chinese medicine prescription for chronic migraine with minimal side effects. Both paeonol and glycyrrhizic acid exhibit analgesic, neuroprotective and anti-inflammatory properties individually. Our previous research has highlighted their combined effect (PAE + GLY) in ameliorating migraine symptoms. However, there are not yet any studies exploring the mechanism of action of PAE + GLY in the treatment of migraine. Aim of the studyThis research aimed to determine the mechanism of PAE + GLY in ameliorating the recurrent nitroglycerin-induced migraine-like phenotype in rats. Materials and methodsUsing a nitroglycerin-induced migraine model via subcutaneous injection in the neck, we evaluated the effect of PAE + GLY on migraine-like symptoms. Behavioural tests and biomarkers analysis were employed, alongside transcriptome sequencing (RNA-seq). Mechanistic insights were further verified utilising reverse transcription quantitative PCR (RT-qPCR), Western blot (WB), ELISA and immunofluorescence (IF) techniques. ResultsFollowing treatment with PAE + GLY, hyperalgesia threshold and 5-hydroxytryptamine (5-HT) levels increased, and migraine-like head scratching, histamine and calcitonin gene-related peptide (CGRP) levels were reduced. RNA-Seq experiments revealed that PAE + GLY upregulated the expression of Glutamate decarboxylase 2 (GAD2) and γ-aminobutyric acid type B receptor subunit 2 (GABBR2) genes. This upregulation activated the GABAergic synapse pathway, effectively inhibiting migraine attacks. Further validation demonstrated an increase in γ-aminobutyric acid (GABA) content in cerebrospinal fluid post PAE + GLY treatment, coupled with increased expression of dural GAD2, GABBR2 and transient receptor potential channel M8 (TRPM8). Consequently, this inhibited the expression of dural cAMP-dependent protein kinase catalytic subunit alpha (PRKACA) and transient receptor potential channel type 1 (TRPV1), subsequently downregulating p-ERK1/2, p-AKT1, IL-1β and TNF-α. ConclusionsOur findings underscore that PAE + GLY ameliorates inflammatory hyperalgesia migraine by upregulating inhibitory neurotransmitters and modulating the GABBR2/TRPM8/PRKACA/TRPV1 pathway.

Lactiplantibacillus plantarum N4 ameliorates lipid metabolism and gut microbiota structure in high fat diet-fed rats.

Lowing blood lipid levels with probiotics has good application prospects. This study aimed to isolate probiotics with hypolipidemic efficacy from homemade na dish and investigate their mechanism of action. In vitro experiments were conducted to determine the cholesterol-lowering ability of five isolates, with results showing that Lactiplantibacillus plantarum N4 exhibited a high cholesterol-lowering rate of 50.27% and significant resistance to acid (87%), bile salt (51.97%), and pepsin (88.28%) in simulated gastrointestinal fluids, indicating promising application prospects for the use of probiotics in lowering blood lipids. The findings from the in vivo experiment demonstrated that the administration of N4 effectively attenuated lipid droplet accumulation and inflammatory cell infiltration in the body weight and liver of hyperlipidemic rats, leading to restoration of liver tissue morphology and structure, as well as improvement in lipid and liver biochemical parameters. 16S analysis indicated that the oral administration of N4 led to significant alterations in the relative abundance of various genera, including Sutterella, Bacteroides, Clostridium, and Ruminococcus, in the gut microbiota of hyperlipidemia rats. Additionally, fecal metabolomic analysis identified a total of 78 metabolites following N4 intervention, with carboxylic acids and their derivatives being the predominant compounds detected. The transcriptomic analysis revealed 156 genes with differential expression following N4 intervention, leading to the identification of 171 metabolic pathways through Kyoto Encyclopedia of Genes and Genomes enrichment analysis. Notably, the glutathione metabolism pathway, PPAR signaling pathway, and bile secretion pathway emerged as the primary enrichment pathways. The findings from a comprehensive multi-omics analysis indicate that N4 influences lipid metabolism and diminishes lipid levels in hyperlipidemic rats through modulation of fumaric acid and γ-aminobutyric acid concentrations, as well as glutathione and other metabolic pathways in the intestinal tract, derived from both the gut microbiota and the host liver. This research offers valuable insights into the therapeutic potential of probiotics for managing lipid metabolism disorders and their utilization in the development of functional foods.

Associations of Plasma Glutamatergic Metabolites with Alpha Desynchronization during Cognitive Interference and Working Memory Tasks in Asymptomatic Alzheimer's Disease.

Electroencephalogram (EEG) studies have suggested compensatory brain overactivation in cognitively healthy (CH) older adults with pathological beta-amyloid(Aβ42)/tau ratios during working memory and interference processing. However, the association between glutamatergic metabolites and brain activation proxied by EEG signals has not been thoroughly investigated. We aim to determine the involvement of these metabolites in EEG signaling. We focused on CH older adults classified under (1) normal CSF Aβ42/tau ratios (CH-NATs) and (2) pathological Aβ42/tau ratios (CH-PATs). We measured plasma glutamine, glutamate, pyroglutamate, and γ-aminobutyric acid concentrations using tandem mass spectrometry and conducted a correlational analysis with alpha frequency event-related desynchronization (ERD). Under the N-back working memory paradigm, CH-NATs presented negative correlations (r = ~-0.74--0.96, p = 0.0001-0.0414) between pyroglutamate and alpha ERD but positive correlations (r = ~0.82-0.95, p = 0.0003-0.0119) between glutamine and alpha ERD. Under Stroop interference testing, CH-NATs generated negative correlations between glutamine and left temporal alpha ERD (r = -0.96, p = 0.037 and r = -0.97, p = 0.027). Our study demonstrated that glutamine and pyroglutamate levels were associated with EEG activity only in CH-NATs. These results suggest cognitively healthy adults with amyloid/tau pathology experience subtle metabolic dysfunction that may influence EEG signaling during cognitive challenge. A longitudinal follow-up study with a larger sample size is needed to validate these pilot studies.

Identification and Characterization of Polyamine Metabolism in Citrus in Response to 'Candidatus Liberibacter asiaticus' Infection.

Citrus Huanglongbing, one of the most devastating citrus diseases, is caused by 'Candidatus Liberibacter asiaticus' (CLas). Polyamines are aliphatic nitrogen-containing compounds that play important roles in disease resistance and are synthesized primarily by two pathways: an arginine decarboxylation pathway and an ornithine decarboxylation pathway. However, it is unclear whether polyamines play a role in the tolerance of citrus to infection by CLas and, if so, whether one or both of the core polyamine metabolic pathways are important. We used high-performance liquid chromatography and ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry to detect the contents of nine polyamine metabolism-related compounds in six citrus cultivars with varying levels of tolerance to CLas. We also systematically detected the changes in polyamine metabolism-related compounds and H2O2 contents and compared the gene expression levels and the activities of enzymes involved in the polyamine metabolic pathway among healthy, asymptomatic, and symptomatic leaves of Newhall navel oranges infected with CLas. The tolerant and moderately tolerant varieties showed higher polyamine metabolism-related compound levels than those of susceptible varieties. Compared with the healthy group, the symptomatic group showed significantly increased contents of arginine, ornithine, γ-aminobutyric acid, and putrescine by approximately 180, 19, 1.5, and 0.2 times, respectively, and upregulated expression of biosynthetic genes. Arginase and ornithine decarboxylase enzyme activities were the highest in the symptomatic group, whereas arginine decarboxylase and agmatine deiminase enzyme activities were the highest in the asymptomatic group. The two polyamine biosynthetic pathways showed different trends with the increase of the CLas titer, indicating that polyamines were mainly synthesized through the arginine decarboxylase pathway in the asymptomatic leaves and were synthesized via the ornithine decarboxylase pathway in symptomatic leaves. These findings provide new insight into the changes in polyamine metabolism in citrus infected with CLas.

A lychee1e fermentate with enriched acetate but lowered GABA attenuates DSS-induced colitis by reinforcing gut barrier function and modulating intestinal microbiota

Fermented plant-based foods have been demonstrated to exert anti-inflammatory effects. However, whether probiotic-fermented lychee exerts beneficial effects on gut barrier functions is still unclear. Using a mouse model, this study investigated the alleviative effects on adherent-invasive Escherichia coli (AIEC)-associated colitis of a lychee fermentate (LF), which was prepared by fermenting lychee fruit (LG) with four beneficial microbes. Results showed that both LG and LF alleviated colitis symptoms. Compared with LG, LF showed greater protective effects on colonic histomorphology and had lower serum TNF-α levels, which were linked to the increased acetate but reduced γ-aminobutyric acid contents in LF. Interestingly, lower concentration of LF (LLF) exerted greater protective effects indicated by all parameters assessed. Microbial profiling showed that LLF led to greater community homogeneity, downregulated Escherichia-Shigella abundance, but promoted Parvibacteria that negatively correlated with IL-6 and TNF-α. Collectively, lychee fermentate, with desirable concentration, could be a novel functional food to promote gut barrier functions.

Heat Waves Coupled with Nanoparticles Induce Yield and Nutritional Losses in Rice by Regulating Stomatal Closure.

The frequency, duration, and intensity of heat waves (HWs) within terrestrial ecosystems are increasing, posing potential risks to agricultural production. Cerium dioxide nanoparticles (CeO2 NPs) are garnering increasing attention in the field of agriculture because of their potential to enhance photosynthesis and improve stress tolerance. In the present study, CeO2 NPs decreased the grain yield, grain protein content, and amino acid content by 16.2, 23.9, and 10.4%, respectively, under HW conditions. Individually, neither the CeO2 NPs nor HWs alone negatively affected rice production or triggered stomatal closure. However, under HW conditions, CeO2 NPs decreased the stomatal conductance and net photosynthetic rate by 67.6 and 33.5%, respectively. Moreover, stomatal closure in the presence of HWs and CeO2 NPs triggered reactive oxygen species (ROS) accumulation (increased by 32.3-57.1%), resulting in chloroplast distortion and reduced photosystem II activity (decreased by 9.4-36.4%). Metabolic, transcriptomic, and quantitative real-time polymerase chain reaction (qRT-PCR) analyses revealed that, under HW conditions, CeO2 NPs activated a stomatal closure pathway mediated by abscisic acid (ABA) and ROS by regulating gene expression (PP2C, NCED4, HPCA1, and RBOHD were upregulated, while CYP707A and ALMT9 were downregulated) and metabolite levels (the content of γ-aminobutyric acid (GABA) increased while that of gallic acid decreased). These findings elucidate the mechanism underlying the yield and nutritional losses induced by stomatal closure in the presence of CeO2 NPs and HWs and thus highlight the potential threat posed by CeO2 NPs to rice production during HWs.