Liquid Chromatography-tandem Mass Spectrometry Research Articles

Biosynthesis-Based Spatial Metabolome of Condensed Tannin Reveals Its Role in Salt Tolerance of Non-Salt-Secretor Mangrove Kandelia obovata.

An autofluorescent inclusion (AFI) specifically accumulated in mesophyll cells (MCs) of non-salt-secretor mangrove was found to be related to salt, but its biosynthesis and spatial distribution characteristics remain unclear. Here, Kandelia obovata served as the experimental material, and the composition of AFI was identified as condensed tannin (CT). Na contents increased in purified AFIs under NaCl treatment, while Na+ efflux in MCs was lower than the control. In vitro, Na+ addition caused aggregations of AFIs. Proteins related to Na+/H+ and vesicle transport were identified in the purified AFIs by liquid chromatography-mass spectrometry. TEM images revealed the structures involved in CT biosynthesis in chloroplasts and CT accretions in vacuoles were more visible under higher salinity. Spatial metabolomics analysis on flavonoid metabolites involving in CT biosynthesis illustrated those flavonoids and three CT monomers were positively related to salt in MCs. Real-time quantitative PCR verified the genes encoding enzymes for CT biosynthesis were upregulated accordingly. Taken together, CT biosynthesis is positively correlated with Na accumulation in leaves. The CTs synthesized in chloroplasts are transported as shuttles to vacuole via cytoplasm, facilitating the sequestration and compartmentalization of excessive Na+ ions into the vacuole, which confers non-salt-secretor mangrove K. obovata a higher salt tolerance.

High-altitude hypoxia exposure alters follicular metabolome and oocyte developmental potential in women.

To explore the effects of high-altitude hypoxia on the microenvironment of oocyte development and fertilization potential, we compared the metabolomic patterns of follicular fluid from women living in different altitude areas and traced their oocyte maturation and subsequent development. A total of 315 clinical cases were collected and divided into three groups according to their residence altitudes: 138 cases in low-altitude (< 2300m) group, 100 cases in middle-altitude (2300-2800m) group and 77 cases in high-altitude (> 2800m) group. The clinical outcomes were statistically estimated, including hormonal level, oocyte maturation, in vitro fertilization, and embryo development. Meanwhile, a metabolomic analysis was performed on the follicular fluid of women from different groups using ultra-high-performance liquid chromatography and high-resolution mass spectrometry and differential metabolites were analyzed through the KEGG pathway. The clinical data indicated that the physical condition and reproductive hormone secretion were similar among different groups. Although personalized gonadotropin-releasing hormone strategies were applied, the numbers of antral follicles and obtained oocytes were not impacted by the residence altitude change. In in vitro culture, the maturing rate, fertility rate and cleavage rate of high-altitude group were compared with the other groups. However, the rates of high-quality embryo, formative blastocyst, and available blastocyst were gradually decreased with the rise of residence altitude. Metabolome analysis identified 1193 metabolites in female follicular fluid. Differential analysis indicated that metabolic components in follicular fluid were remarkably changed with the elevation of residence altitude. These differential metabolites were closely related with amino acid metabolism, protein digestion and absorption, oocyte meiosis and steroid biosynthesis. The residence altitude alters the microenvironment of follicular fluid, which could damage the oocyte developmental potential. This study provides diagnostic basis and therapeutic targets for research on female oocyte and embryo development.

Endophytic Bacillus velezensis GsB01 controls Gleditsia sinensis wilt by secreting antifungal metabolites and modulates symbiotic microbiota within trees.

Identifying effective biological control agents against fungal pathogens and determining their mechanisms of action are important in the control of plant diseases. In this study, we isolated an endophytic bacterial strain, GsB01, from the branches of asymptomatic Gleditsia sinensis. Multi-locus sequence analysis identified the strain as Bacillus velezensis. GsB01 exhibited significant antifungal activity against Thyronectria austroamericana, the causative agent of G. sinensis wilt. Liquid chromatography-mass spectrometry identified four consistently present antimicrobial compounds in GsB01 metabolite fractions with high antifungal activity: macrolactin A, bacillaene A, surfactin, and iturin. GsB01's active metabolite fractions altered the metabolic profiles of T. austroamericana, disrupting seven pathways, including arginine biosynthesis, nucleotide metabolism, purine metabolism, and the pentose phosphate pathway. Furthermore, absolute quantitative polymerase chain reaction analysis suggested that GsB01 may increase the abundance of endophytic bacteria in G. sinensis. The 16S rRNA amplicon sequencing revealed changes in the endophytic landscape in stems and roots following GsB01 introduction, particularly with significant variation in the dominant bacterial genera within the stems. The study highlights GsB01's potential against plant wilt and suggests that its antifungal activity is achieved by secreting antifungal metabolites. The study also recorded changes in the symbiotic microbiota within trees that had been infected with a pathogenic fungus and subsequently treated with an endophytic antagonistic bacterial strain. © 2024 Society of Chemical Industry.

Hydrophobic deep eutectic solvent-ferrofluid microextraction followed by liquid chromatography-mass spectrometry for the enantioselective determination of chiral agrochemicals in natural waters.

The increasing use of chiral agrochemicals sold as racemic formulations raises concern for the negative impacts that inactive enantiomers can have on aquatic life and human health. The present work just focuses on the determination of ten chiral pesticides in river water samples by applying a ferrofluid-based microextraction followed by their stereoselective liquid chromatography analysis. To develop the ferrofluid, magnetite nanoparticles were prepared and coated with oleic acid and then dispersed in a hydrophobic natural deep eutectic solvent (NaDES), composed ofL-menthol and thymol (1:1). The stable colloidal dispersion was characterised by scanning electron microscopy, thermogravimetric analysis, energy-dispersive X-ray spectroscopy and attenuated total reflection Fourier transform infrared spectroscopy. The analyte microextraction from 5ml river samples was performed using 50µl of ferrofluid, while acidified acetonitrile (150µl) was used to break down the ferrofluid and solubilise the NaDES containing the analytes. All the extracts were analysed by high-performance liquid chromatography-tandem mass spectrometry. For each analyte, the baseline separation of isomers was achieved on a Lux i-Amylose-3 column (amylose tris(3-chloro-5-methylphenylcarbamate) working in reversed-phase mode; the combination with mass spectrometry detection allows the overall separation of 24 isomers (ten chiral analytes among which eight containing a single (one) chiral centre, one with two chiral centres and the last one existing in four stereoisomeric forms, due to the presence of two regioisomers with a chiral carbon) within 37min. The method showed very good figures of merit in terms of recoveries (77.7-97.5%), intra-day and inter-day precision (2.7-7.7% and 6.9-14.9%, respectively), limit of detection (0.01-0.35µg/L), limit of quantitation (0.03-1.20µg/L), linear dynamic range, and intra-day and inter-day accuracy (1.2-14.8% and 1.8-15.0%, respectively). The presented method was able to detect 14 out of 24 isomers at the preventive limit established by the Italian legislation for single pesticide (that for a chiral pesticide is the sum of all its isomers) in surface waters, set at 0.1µg/l. Finally, the method was evaluated using AGREEprep and ComplexGAPI metrics, compared with other ferrofluid-based methods, and applied to the analysis of water samples from two Italian rivers (the Nera River and the Tiber River), providing to be sustainable and reliable for the application to real river matrices.

Z-Scheme Enabled 1D/2D Nanocomposite of ZnO Nanorods and Functionalized g-C3 N4 Nanosheets for Sustainable Degradation of Terephthalic Acid.

The urgent need to mitigate water pollution and achieve Sustainable Development Goal 14 (SDG 14)-Life below water, necessitates developing efficient and eco-friendly wastewater treatment technologies. This research addresses this challenge by photocatalytic degradation of terephthalic acid, a precursor for PET bottles using environment-friendly and biocompatible photocatalysts. The 1D/2D nanocomposite comprising zinc oxide (ZnO) nanorods and functionalized graphitic carbon nitride (Zn-TG) nanosheets were synthesized and thoroughly characterized. The nanocomposite effectively mitigated the individual drawbacks of Zn-TG agglomeration and the wide band gap of ZnO as confirmed through zeta potential and Tauc's plot studies, respectively. The synthesized nanocomposite achieved ~100 % degradation within 60 minutes, exhibiting superior kinetics (~2.5 times) compared to pristine samples. The enhanced degradation efficiency was elucidated by efficient charge carrier transfer (~5 times faster) and separation (~2 times improved) as confirmed through electrochemical impedance spectroscopy and time-resolved photoluminescence studies. The proposed Z-scheme pathway provides mechanistic insights. This proposed mechanism is supported by extensive electron paramagnetic resonance (EPR) and scavenger studies. The liquid chromatography-mass spectrometry (LC-MS) analysis confirms the formation of less toxic byproducts for ensuring that the wastewater treatment process is efficient and environmentally friendly. This research helps in developing a highly effective and sustainable wastewater treatment technology.

Biostimulant-Based Molecular Priming Improves Crop Quality and Enhances Yield of Raspberry and Strawberry Fruits

Background/Objectives: The biostimulant SuperFifty, produced from the brown algae Ascophyllum nodosum, can improve crop quality and yield and mitigate stress tolerance in model and crop plants such as Arabidopsis thaliana, pepper, and tomato. However, the effect of SuperFifty on raspberries and strawberries has not been well studied, especially in terms of nutritional properties and yield. The aim of this study was to investigate the effect of SuperFifty on the quality and quantity of raspberry and strawberry fruits, with a focus on metabolic composition and essential elements, which together determine the nutritional properties and total yield of these two crops. Methods: Metabolome analysis was performed by liquid chromatography–mass spectrometry analysis (LC-MS), and essential elements analysis was performed by inductively coupled plasma-mass spectrometry (ICP-MS). Results: Here, we demonstrate that SuperFifty increases the fruit size of both raspberries and strawberries and enhances the yield in these two berry crops by 42.1% (raspberry) and 33.9% (strawberry) while preserving the nutritional properties of the fruits. Metabolome analysis of 100 metabolites revealed that antioxidants, essential amino acids, organic acids, sugars, and vitamins, such as glutathione, alanine, asparagine, histidine, threonine, serine, tryptophan, sucrose, citric acid, pantothenic acid (vitamin B5), as well as other primary metabolites, remain the same in the SuperFifty-primed fruits. Secondary metabolites, such as caffeic acid, p-coumaric acid, kaempferol, and quercetin, also maintained their levels in the SuperFifty-primed fruits. Analysis of essential elements demonstrated that elements important for human health, such as Zn, Mn, Fe, B, Cu, K, and Ca, maintain the same levels in the raspberry and strawberry fruits obtained from the biostimulant-primed plants. Magnesium, an important element known as a co-factor in many enzymatic reactions related to both plant physiology and human health, increased in both raspberry and strawberry fruits primed with SuperFifty. Finally, we discuss the potential financial and health benefits of the SuperFifty-induced priming for both growers and consumers. Conclusions: We demonstrate that SuperFifty significantly enhances the yield of both raspberries and strawberries, improves the marketable grade of the fruits (larger and heavier fruits), and enhances the nutritional properties by elevating Mg content in the fruits. Altogether, this biostimulant-induced molecular priming offers an environmentally friendly, efficient, and sustainable way to enhance the yield and quality of berry crops, with clear benefits to both berry producers and customers.

Multiplatform metabolomic interlaboratory study of a whole human stool candidate reference material from omnivore and vegan donors.

Human metabolomics has made significant strides in understanding metabolic changes and their implications for human health, with promising applications in diagnostics and treatment, particularly regarding the gut microbiome. However, progress is hampered by issues with data comparability and reproducibility across studies, limiting the translation of these discoveries into practical applications. This study aims to evaluate the fit-for-purpose of a suite of human stool samples as potential candidate reference materials (RMs) and assess the state of the field regarding harmonizing gut metabolomics measurements. An interlaboratory study was conducted with 18 participating institutions. The study allowed for the use of preferred analytical techniques, including liquid chromatography-mass spectrometry (LC-MS), gas chromatography-mass spectrometry (GC-MS), and nuclear magnetic resonance (NMR). Different laboratories used various methods and analytical platforms to identify the metabolites present in human stool RM samples. The study found a 40% to 70% recurrence in the reported top 20 most abundant metabolites across the four materials. In the full annotation list, the percentage of metabolites reported multiple times after nomenclature standardization was 36% (LC-MS), 58% (GC-MS) and 76% (NMR). Out of 9,300 unique metabolites, only 37 were reported across all three measurement techniques. This collaborative exercise emphasized the broad chemical survey possible with multi-technique approaches. Community engagement is essential for the evaluation and characterization of common materials designed to facilitate comparability and ensure data quality underscoring the value of determining current practices, challenges, and progress of a field through interlaboratory studies.

Sea Buckthorn Flavonoid Extracted with High Hydrostatic Pressure Alleviated Shrimp Allergy in Mice through the Microbiota and Metabolism.

Sea buckthorn (Hippophaë rhamnoides L.) known as the deciduous shrub has been reported to have effects of antioxidant, anti-inflammatory, and immunomodulatory activities. Tropomyosin (TM) induced a regulatory immune response associated with food allergy. In this study, a mouse model of food allergy sensitized to tropomyosin (TM) was established to assess the antiallergic properties of sea buckthorn flavonoid extract (SBF). SBF alleviated mice's allergic symptoms and exhibited a significant reduction in the levels of IgE and histamine. Meanwhile, SBF repaired the allergic Th2 cell overpolarization generated by TM, via downregulating the IL-4 production and upregulating IFN-γ production to restore the balance of Th1/Th2 cells. Furthermore, the 16S RNA analysis showed that SBF primarily restored the gut microbiota via increasing the abundance in Chitinophilidae and decreasing in Burkholderiaceae, Pneumatobacteriaceae, and Sphingomonadaceae. Gut metabolomes determined by liquid chromatography-mass spectrometry (LC-MS) suggested that TM upregulated PE (14:0/22:1(13Z)) and SBF decreased formimino-l-glutamic acid and urocanic acid levels. According to the KEGG pathway analysis, SBF treatment has been shown to modulate glycerophospholipid and histidine metabolism to improve allergic reactions. SBF holds great promise as a novel potential agent for the treatment of food allergies.

Validation of an LC-MS/MS Method for Analysis of 58 Drugs of Abuse in Oral Fluid and Method Comparison with an Established LC-HRMS Method.

Liquid chromatography-mass spectrometry (LC-MS) methods for detection of multiple drugs of abuse (DoA) in oral fluid (OF) samples are being implemented in many clinical routine laboratories. Therefore, there is a need to develop new multi-analyte methods with simple sample pre-treatment and short analysis times. The purpose of this work was to validate a method detecting 58 DoA to be used with two different OF sampling kits, the saliva collection system (SCS) from Greiner Bio-One and Quantisal from Immunalysis, using the same sample pretreatment and analytical method. A set of 110 samples collected with the SCS kit was further compared to an LC-HRMS (high resolution mass spectrometry) method in another laboratory. The method was successfully validated, with precision and accuracy of ≤15% and z-scores of <2 for external controls. Using a sensitive LC-MS/MS instrument, the detection limits were <1 µg/L in neat oral fluid. In the comparative study between the LC-MS/MS and LC-HRMS methods using SCS samples, a good agreement was observed. Discrepancies were limited to lower concentration ranges, attributable to differences in cut-off thresholds between the methods. This work contributes to the development of LC-MS multi-analyte methods for OF samples, which are suitable for clinical routine laboratories.

Application of metabolomics approach to investigate the flavor substance differences between triploid and diploid oysters (Crassostrea angulata)

Oysters, particularly Portuguese oyster (Crassostrea angulata), are highly valued for their nutritional and flavor qualities, making them important in global aquaculture. Triploid oysters have gained attention for maintaining higher meat quality year-round compared to diploids, but there is limited research on how ploidy affects their biochemical and flavor profiles. This study uses a non-targeted metabolomics approach, including gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS), to investigate flavor substance differences between triploid and diploid C. angulata. A total of 13 volatile compounds were identified in diploid oysters, while 28 were found in triploids. Significant upregulation of inosine, guanosine, L-aspartic acid, and taurine in triploids contributes to their enhanced flavor profile. Additionally, triploids showed higher nicotinamide concentrations, while diploids had increased 25-hydroxycholesterol. These findings highlight the advantages of triploid oysters in aquaculture for improved flavor and nutrition, supporting their potential for year-round production.

Study on the Mechanism of Raspberry (Rubi fructus)in Treating Type 2 Diabetes Based on UPLC-Q-Exactive Orbitrap MS, Network Pharmacology, and Experimental Validation.

The aim of this study is to analyze the chemical composition of raspberry using liquid chromatography-mass spectrometry (LC-MS) technology, predict the potential effects of raspberry in treating type 2 diabetes through network pharmacology, and conduct preliminary validation through invitro experiments. A Waters CORTECS C18 column (3.0 mm × 100 mm, 2.7 μm) was used; mobile phase A consisted of 0.1% formic acid in water and mobile phase B consisted of 0.1% formic acid in acetonitrile. Gradient elution was performed with full-scan mode in both positive and negative ion modes, covering a mass range of m/z 100-1500. The chemical components of raspberry were analyzed and identified based on secondary spectra from databases and relevant literature. The disease targets related to type 2 diabetes were searched, and protein-protein interaction network analysis as well as gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were conducted on the intersecting targets of the active components of raspberry and the disease. HepG2 cells were used for experimental validation, with high glucose-induced insulin resistance models established. The CCK-8 method was employed to assess the effects of raspberry on cell proliferation, while Western blotting was used to measure the expression of proteins related to the AGE/RAGE signaling pathway. A total of 47 components were identified, including 10 organic acids, 15 flavonoids, 12 phenols, 2 alkaloids, 4 terpenoids, 1 miscellaneous compound, 1 stilbene, 1 steroid and its derivatives, and 1 diterpenoid. Through database screening, seven active components were identified: kaempferol, epicatechin, ellagic acid, crocetin, stigmasterol, fisetin, and isorhamnetin. KEGG and GO results indicated that the therapeutic effects of raspberry on type 2 diabetes may be related to the advanced glycation end product (AGE)- receptor for advanced glycation end product (RAGE) signaling pathway. Establishment of an insulin resistance model in HepG2 cells demonstrated that, compared to the control group, the raspberry treatment group upregulated p53 protein expression while downregulating the expression of RAGE, Akt1, and Caspase-3 proteins. This study preliminarily elucidates that the therapeutic effects of raspberry in treating type 2 diabetes may be mediated through the inhibition of the AGE-RAGE signaling pathway, providing important references for the study of the pharmacological basis and clinical application of raspberry.

Development and validation of an LC‒MS/MS method for the determination of cyclocreatine phosphate and its related endogenous biomolecules in rat heart tissues

The cardioprotective drug cyclocreatine phosphate has been awarded Food and Drug Administration-orphan drug designation for the prevention of ischemic injury to enhance cardiac graft recovery and survival in heart transplantation. Cyclocreatine phosphate is the water-soluble derivative of cyclocreatine. Estimating the levels of Cyclocreatine phosphate, Adenosine triphosphate, Creatine Phosphate, Creatine and Cyclocreatine helps us in understanding the energy state as well as evaluating the heart cells’ function. The quantification of endogenous compounds imposes a challenging task for analysts because of the absence of a true blank matrix, whose use is required according to international guidelines. Recently, the International Council for Harmonization issued a new guideline that contains guidance on the validation of methods used to quantify endogenous components, such as the background subtraction approach that was employed in our current study. Specifically, we developed and validated a sensitive, reliable and accurate liquid chromatography-tandem mass spectrometry assay to determine simultaneously the levels of mentioned endogenous compounds in rat heart tissue. Tissue samples were prepared by protein precipitation extraction using water: methanol (1:1). Using Ultra Performance Liquid Chromatography, Chromatographic separation was achieved with ZORBAX Eclipse Plus C18 4.6 × 100 mm,3.5 μm column and conditions as following: ammonium acetate (pH 8.5): acetonitrile, 70:30 mobile phase, 0.7 mL/min flow rate and 25 °C temperature. Electrospray ionization mass detector with Multiple reaction monitoring mode was then employed, using both positive and negative modes, Analysis was carried out using 5.00–2000.00 ng/mL linear concentration range within 2 min for each analyte. According to Food and Drug Administration guidelines for bioanalytical methods, validation was carried out. We investigated the matrix effect, recovery efficiency and process efficiency for the analyte in neat solvent, postextraction matrix and tissue. The results stated mean percentage recoveries higher than 99%, accuracy 93.32–111.99%, and Relative Standard Deviation (RSD) below 15% within the concentration range of our study which indicated that target analytes’ stability in their real matrix is sufficient under the employed experimental conditions.

Metabolomic analysis of HUVEC after Thermal denaturation UHPLC-MS/MS-based metabolomics.

Preserving denatured dermis has been shown to promote wound healing and improve skin appearance and function. Angiogenesis is crucial for the healing of burn wounds. However, the metabolic mechanisms underlying angiogenesis during burn recovery remain unclear. In this study, ultra-high performance liquid chromatography-mass spectrometry analysis revealed six distinct metabolites in a heat-denatured cell model. A bioinformatics approach was used to predict the differentially expressed metabolites, and four metabolic pathways closely related to trauma repair were identified. These pathways might play a significant role in the regression of thermally injured endothelial cells. We also found that increasing D-mannose level promoted the angiogenic activity of human umbilical vein endothelial cells in the heat-denatured cell model, enhancing cell proliferation, migration, and tube formation. In summary, these findings revealed changes in metabolites and metabolic pathways in thermally injured endothelial cells, and demonstrated that D-mannose could promote angiogenesis during the recovery of thermally injured endothelial cells.

Bio-based sulfonated surfactants with high Ca2+ tolerance in detergent formulations

The use of calcium-resistant surfactants in household and industrial washing applications may simplify the formulation composition of laundry and therefore reduce costs. A series of bio-based surfactants, N-alkyl furfuryl methylamine sulfonates (AFMS), was developed from the biomass-derived furfural and aliphatic amines by a simple and effective method. The structure of these bio-based surfactants was characterized by gas chromatography–mass spectrometry, liquid chromatography–mass spectrometry and 1H nuclear magnetic resonance spectroscopy. These bio-based surfactants demonstrated low surface tension, high emulsification, and high decontamination efficiency. Meanwhile, the AFMS surfactants exhibited excellent calcium resistance, maintaining micelle stability in Ca2+up to 2.16 × 104 mg/L and the solution clarification in Ca2+up to 7.21 × 104 mg/L. Furthermore, the AFMS surfactants had a stable decontamination effect in hard water. The wetting ability, foaming ability, toxicity, and biodegradability parameters were also evaluated. Therefore, the AFMS surfactants synthesized in this work could be applied as a more efficient and promising bio-based surfactant candidate for application in household and industrial washing.

Characterization of putative antimicrobial compounds produced by endolichenic Fusarium solani exposed to light treatments

ABSTRACT The endolichenic Fusarium solani (EF5), known to show induced metabolite production when exposed to red and green lights, was selected for characterization of their putative light-regulated bioactive compounds. To achieve this, fractionation was first performed for crude extracts from cultures of F. solani (EF5) incubated in green, red, white-fluorescent light and dark conditions. The extract yielded 12 (dark condition) to 15 (exposed to green, red, and white-fluorescent lights) fractions, and each of the fractions was tested for antimicrobial activities. The fraction (fraction 5) that showed the most promising antimicrobial activity was then subjected to high-performance liquid chromatography (HPLC) and liquid chromatography–mass spectrometry (LC-MS) to identify the bioactive compounds. Results revealed detection of two new metabolites from endolichenic F. solani, putatively identified as 8-deoxyjavanicin and fusolanone A, which are known to have antimicrobial properties. This study revealed that red and green lights trigger the production of 8-deoxyjavanicin and fusolanone A, which likely contributed to the antimicrobial properties demonstrated by endolichenic F. solani.

Identification of novel hypertension biomarkers using explainable AI and metabolomics

BackgroundThe global incidence of hypertension, a condition of elevated blood pressure, is rising alarmingly. According to the World Health Organization’s Qatar Hypertension Profile for 2023, around 33% of adults are affected by hypertension. This is a significant public health concern that can lead to serious health complications if left untreated. Metabolic dysfunction is a primary cause of hypertension. By studying key biomarkers, we can discover new treatments to improve the lives of those with high blood pressure.AimsThis study aims to use explainable artificial intelligence (XAI) to interpret novel metabolite biosignatures linked to hypertension in Qatari Population.MethodsThe study utilized liquid chromatography-mass spectrometry (LC/MS) method to profile metabolites from biosamples of Qatari nationals diagnosed with stage 1 hypertension (n = 224) and controls (n = 554). Metabolon platform was used for the annotation of raw metabolite data generated during the process. A comprehensive series of analytical procedures, including data trimming, imputation, undersampling, feature selection, and biomarker discovery through explainable AI (XAI) models, were meticulously executed to ensure the accuracy and reliability of the results.ResultsElevated Vanillylmandelic acid (VMA) levels are markedly associated with stage 1 hypertension compared to controls. Glycerophosphorylcholine (GPC), N-Stearoylsphingosine (d18:1/18:0)*, and glycine are critical metabolites for accurate hypertension prediction. The light gradient boosting model yielded superior results, underscoring the potential of our research in enhancing hypertension diagnosis and treatment. The model’s classification metrics: accuracy (78.13%), precision (78.13%), recall (78.13%), F1-score (78.13%), and AUROC (83.88%) affirm its efficacy. SHapley Additive exPlanations (SHAP) further elucidate the metabolite markers, providing a deeper understanding of the disease’s pathology.ConclusionThis study identified novel metabolite biomarkers for precise hypertension diagnosis using XAI, enhancing early detection and intervention in the Qatari population.

Pharmacokinetic Drug-Drug Interaction between Cilostazol and Rosuvastatin in Healthy Participants.

Cilostazol improves ischemic symptoms and prevents recurrence following cerebral infarction, and rosuvastatin reduces cholesterol levels. However, no reports exist on the pharmacokinetic interactions between these two drugs in healthy adults. This study evaluated the pharmacokinetic (PK) interactions and safety of cilostazol and rosuvastatin when co-administered to healthy male participants. A randomized, open-label, multiple-dosing, two-arm, two-period study was conducted. Arm A had 30 participants receiving 200 mg cilostazol daily and arm B had 27 participants receiving 20 mg rosuvastatin daily for 7 days. In period 2, both arms received a combination of 200 mg cilostazol and 20 mg rosuvastatin daily for 7 days following a 7-day washout period. Plasma concentrations of cilostazol, its metabolites, and rosuvastatin were quantified using liquid chromatography-tandem mass spectrometry. Fifty-seven participants were randomized, and 44 completed the study. The geometric mean ratio (GMR) and 90% confidence intervals (CI) for maximum plasma concentration at steady state (Cmax,ss) and area under the plasma concentration-time curve during the dosing interval at steady state (AUCtau,ss) indicated no significant interaction between cilostazol and rosuvastatin. Safety assessments showed comparable profiles to individual drug administration, with no significant adverse events. The repeated co-administration of cilostazol and rosuvastatin in healthy male participants resulted in minor PK interactions and exhibited a safety and tolerability profile similar to those of the individual drugs. This suggested that the combined regimen is well tolerated and does not necessitate dose adjustments. ClinicalTrials.Gov identifier no. NCT06568133.

Rapid and Simultaneous Determination of 13 Sulfonamides in Soil by Matrix Solid-Phase Dispersion With High-Performance Liquid Chromatography-Tandem Mass Spectrometry.

Sulfonamides, the most frequent antibacterial agent, are widely used due to their low cost and excellent antibacterial effect. With the emergence of the environment, the potential hazard to the ecological environment has attracted the great attention of humans. Based on matrix solid-phase dispersion coupled with high-performance liquid chromatography-tandem mass spectrometry, an accurate, fast, and sensitive analytical method was developed for the determination of sulfonamides (SAs) in soil. Several influencing factors including the type of dispersants, the ratio of sample-to-sorbent, eluents, and solvent volume were investigated, and the matrix effects were evaluated. Under optimized conditions, the calibration curves exhibited excellent linearity with correlation coefficients (r) exceeding 0.996. The limit of detection (based on signal-to-noise ratio [S/N]=3) and limit of quantification (based on S/N=10) were 0.024-0.058 and 0.079-0.195µg/kg, respectively. The recoveries ranging from 70.12% to 123.63% were obtained with a relative standard deviation of less than 15% at three levels (20, 40, and 200µg/kg). The developed method was successfully applied to analyze 13 SAs at trace levels in a real soil sample. This proposed method would be an alternative and suitable for routine application in the future owing to its rapidity, sensitivity, and affordability.

A single-center prospective study of vitamin D levels and its supplementary effect in the first trimester

Objective: To investigate vitamin D levels and the effect of exogenous vitamin D supplementation in the first trimester among pregnant women in our center. Methods: This was a prospective cohort study. A total of 98 women in the first trimester who were followed-up regularly in Peking Union Medical College Hospital from December 1st 2020 to December 1st 2021 were enrolled. Subjects who had medical conditions that affect vitamin D absorption or metabolism were excluded. Questionnaires were administered, and 25-hydroxyvitamin D [25(OH)D] levels were detected using liquid chromatography tandem mass spectrometry (LC/MS/MS) method. According to the basic 25(OH)D level, different dosages of exogenous vitamin D were supplemented. After 4 weeks, 25(OH)D levels were detected again to evaluate the effect of supplementation. T test, analysis of variance, χ2 test, and multiple linear regression analysis were used for analysis. Results: The mean age of enrolled subjects was (33.5±4.0) years. The baseline 25(OH)D level was (41.2±20.0) nmol/L. Briefly, 70.4% (69/98) subjects were deficient in vitamin D, and 42.9% (42/98) patients were using vitamin D supplementation at the time of 25(OH)D testing. Single-factor analysis showed that vitamin D supplementation (t=-4.21, P<0.001), season (t=2.59, P=0.011), and nut-eating frequency (t=2.67, P=0.009) were related to 25(OH)D levels. Multiple linear regression analysis showed that only vitamin D supplementation had a relationship with 25(OH)D level (B=13.84, P=0.006). According to the baseline 25(OH)D level, 400-5 000 U/d vitamin D3 was supplemented regularly for (4.1±2.5) weeks, and 25(OH)D levels significantly increased after supplementation [(64.1±18.1) vs (37.3±16.6) nmol/L, t=-9.36, P<0.001]. The ascending range was negatively associated with basic 25(OH)D level (B=-0.66, P<0.001) and positively associated with supplementary dosage (B=0.51, P<0.001). 25(OH)D levels increased by 0.51 nmol/L on average per 1 μg (40 U) of vitamin D supplementation daily. Conclusions: The proportion of vitamin D deficiency was high in the first trimester among pregnant women in our center. Exogenous vitamin D supplementation could significantly increase 25(OH)D levels, and the effect was negatively associated with basic 25(OH)D level but positively associated with supplementary dosage.

A critical role for microglia in regulating metabolic homeostasis and neural repair after spinal cord injury

Traumatic spinal cord injury (SCI) often results in severe immune and metabolic disorders, aggravating neurological damage and inhibiting locomotor functional recovery. Microglia, as resident immune cells of the spinal cord, play crucial roles in maintaining neural homeostasis under physiological conditions. However, the precise role of microglia in regulating immune and metabolic functions in SCI is still unclear and is easily confused with that of macrophages. In this study, we pharmacologically depleted microglia to explore the role of microglia after SCI. We found that microglia are beneficial for the recovery of locomotor function. Depleting microglia disrupted glial scar formation, reducing neurogenesis and angiogenesis. Using liquid chromatography tandem mass spectrometry (LC‒MS/MS), we discovered that depleting microglia significantly inhibits lipid metabolism processes such as fatty acid degradation, unsaturated fatty acid biosynthesis, glycophospholipid metabolism, and sphingolipid metabolism, accompanied by the accumulation of multiple organic acids. Subsequent studies demonstrated that microglial depletion increased the inhibition of FASN after SCI. FASN inhibition exacerbated malonyl-CoA accumulation and significantly impeded the activity of mTORC1. Moreover, microglial depletion exacerbated the oxidative stress of neurons. In summary, our results indicate that microglia alleviate neural damage and metabolic disorders after SCI, which is beneficial for achieving optimal neuroprotection and neural repair.