Search Results (3,993)

The use of lecithin as an emulsifier in food supplements has increased in recent years. However, successful formation of liposomes or micelles requires an appropriate mixture of phospholipids in lecithin. To evaluate the emulsification properties of lecithin for food supplements, a reliable analytical procedure for characterizing phospholipids is necessary. A liquid chromatography–mass spectrometry method was developed to identify phospholipids in lecithin without standard reference materials. For efficient separation of phospholipids before mass spectrometric analysis, a reverse-phase high-performance liquid chromatography method was optimized using a Waters XBridge Protein BEH C4 column. The optimized chromatographic method demonstrated good linearity and precision. Molecular ions were detected in full scan mode to determine accurate mass-to-charge ratios for individual peaks in the chromatogram. A custom Python program was then used to generate a list of possible phospholipid species for each peak based on the measured mass-to-charge ratios. Tandem mass spectrometry was performed to confirm the identity of specific phospholipids by comparing experimental fragmentation patterns with theoretical predictions. Identification of the phospholipids was also confirmed with four commercially available standard reference compounds, demonstrating the reliability of the proposed approach. The developed method offers a practical and cost-effective strategy for identifying phospholipids in complex matrices, especially when standard reference compounds are unavailable. Additionally, it enables targeted selection of standard compounds for future quantitative analyses, making it a valuable tool for comprehensive lipid profiling. Full article

Background/Objectives: Tea and coffee, two of the most widely consumed beverages worldwide, play important roles in supporting overall health. Changes in the urine proteome reflect the changes in the body influenced by beverage consumption, rather than beverage metabolites. In this study, the effects of teas with different fermentation levels and black coffee on the body were explored via urine proteomics analysis. Methods: Urine samples were collected from rats before and after seven consecutive days of consuming green tea, oolong tea, black tea, Pu-erh tea, or black coffee. Both before-and-after comparisons and between-group comparisons were performed, and the samples were analyzed using liquid chromatography coupled with tandem mass spectrometry. Results: The urine proteome reflected the changes in rats after consumption of teas or black coffee for one week. Biological processes and pathways enriched with differential proteins included fat cell differentiation, lipid metabolism, glucose metabolism, fatty acid transport, and immune response. The effects of teas with different fermentation levels and black coffee on the body exhibited a high degree of specificity. Additionally, several identified differential proteins have been reported as biomarkers for diseases such as cancer and cardiovascular diseases. This suggests that beverage consumption, including tea and black coffee, should be considered in urine biomarker research. And the use of biomarker panels may be necessary to improve accuracy. Conclusions: The urine proteome provides a comprehensive and systematic reflection of the effects of all components in teas and black coffee on the body and allows for the distinction of changes in the body after consumption of teas with different fermentation levels and black coffee. Full article

Background: This study aimed to identify distinct metabolic signatures associated with disease progression by integrating high-resolution computed tomography (HRCT) visual scoring with comprehensive metabolomic profiling. Materials and Methods: This single-center, cross-sectional study enrolled 60 idiopathic pulmonary fibrosis/interstitial lung disease (IPF/ILD) patients with usual interstitial pneumonia pattern. Participants underwent standardized pulmonary function testing, HRCT imaging, and peripheral blood collection for metabolomic analysis using one-dimensional hydrogen nuclear magnetic resonance spectroscopy and ultra-high-performance liquid chromatography coupled to tandem mass spectrometry. Linear regression analysis integrated radiographic scores with metabolomic profiles, adjusted for multiple covariates. Results: Stable IPF/ILD exhibited moderate negative correlations between the six most significant metabolites and HRCT scores (r = −0.27 to −0.51), along with a high abundance of specific phospholipids (triacylglycerol, monoacylglycerol, phosphatidylglycerol, phosphatidylethanolamine, diacylglycerol), sphingomyelin, ceramide, and acylcarnitine. In contrast, progressive disease showed weak positive correlations between the six most significant metabolites and HRCT scores (r = 0.19–0.26), and moderate negative correlation between specific triacylglycerol species and HRCT scores (r = −0.37–0.4). Furthermore, metabolomic analysis in individuals with progressive disease revealed both high and low abundances of specific phospholipid species (including high and low triacylglycerol species, as well as low levels of phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phosphatidylserine, and phosphatidylinositol), along with high levels of certain sphingomyelin, ceramide, taurine, and purine bases, and low levels of xanthine and lactic acid observed. Conclusions: Integration of systematic HRCT semi-quantitative scoring with metabolomic profiling successfully differentiated stable from progressive IPF/ILD through distinct molecular-radiographic signatures. Full article

Background: Plasticisers with endocrine-disrupting potential are ubiquitous and associate with obesity and type-2 diabetes (T2D), with higher levels reported in the Middle East. However, no data exist on plasticiser exposure in Bahrain where T2D affects 15% of the national population. Methods: An observational exploratory study in T2D (n = 60) and controls (n = 96), analysed for 24 h urinary plasticiser levels (liquid chromatography tandem mass spectrometry (LC-MS/MS)). Correlation and generalised linear model (GLM) analyses were employed to examine associations. Results: T2D were older (p < 0.001), had higher body mass index (BMI) (p < 0.001), body weight (p < 0.001) and glycosylated haemoglobin A1c (HbA1c) (p < 0.001). Correlation analysis revealed differences in inter-plasticiser, and plasticiser and biomarker relationships, with loss or reversal in T2D compared to controls. Mono-n-butyl phthalate (MnBP) levels were higher in T2D (p = 0.04); however, regression analysis revealed significant association with age. The GLM analyses demonstrated marked differences in the levels of mono(3-carboxypropyl) phthalate (MCPP), mono(2-ethyl-5-carboxypentyl) phthalate (MECPP), monoethyl phthalate (MEP) and bisphenol S (BPS), with lower levels in T2D versus controls (B = −3.41, p = 0.01; B = −5.28, p < 0.001; B = −8.94, p < 0.001; B = −6.09, p = 0.006, respectively); however, these contrasts appeared to be substantially confounded by BMI and/or age. Positive influence of age and negative influence of BMI when observed across the full dataset were generally reversed in T2D. Levels were complementary to those previously reported for the Middle East. Conclusions: The study indicates the phthalate levels in Bahrain are elevated though complementary to studies of phthalates in the Middle East; within those levels, the study indicates differential exposure–response relationships with plasticisers, influenced by age and BMI, in those with T2D compared to healthy controls. Full article

Background: Advanced glycation end products (AGEs) play a pivotal role in various human pathologies, including aging and metabolic diseases, and their formation may have significant physiological consequences for human health. Fructoselysine (FL) is an intermediate in the formation of AGEs, and its accumulation has been associated with detrimental health effects. Although several chromatographic methods have been developed for AGEs detection and quantification, no mass spectrometry-based approach has previously been established to quantify FL in different human biological matrices. Methods: In this study, we present a novel UHPLC-HRMS/MS method for the identification and quantification of this compound in various biological matrices, including plasma, feces, and urine. Results: The method demonstrates excellent linearity, accuracy, and precision, with limit of detection (LOD) of 0.02 µM and limit of quantification (LOQ) of 0.06 µM. Recovery rates ranged from 95% to 109% and intra- and inter-day relative standard deviations (RSDs) were below 10%, indicating robust analytical performance. The validated method was successfully applied to quantify FL in plasma, feces, and urine samples from healthy individuals. Additionally, given the known association between AGEs and diabetes, we analyzed a small cohort of prediabetic patients and observed elevated circulating levels of FL compared to healthy controls. Conclusions: This study introduces a sensitive and reliable method for the specific detection and quantification of FL in biological samples and provides new insights into early molecular changes associated with prediabetic condition to improve early diagnosis in aging related diseases. Full article

N-Acetyl-D-mannosamine (ManNAc) and N-acetylneuraminic acid (Neu5Ac) are important components of glycosylation, affecting numerous physiologic processes. The effects of age, body mass index (BMI), race, or sex on serum levels of ManNAc and Neu5Ac are poorly understood. However, these associations are of substantial interest. Simultaneous quantification of ManNAc and Neu5Ac, using liquid chromatography tandem mass spectrometry (LC-MS/MS), was developed and validated for human serum samples. This method has high sensitivity, specificity, and reproducibility, with limits of detection as low as 1.02 ng/mL for ManNAc or 1.14 ng/mL for Neu5Ac. A set of 155 serum samples from the Adventist Health Study 2 (AHS-2) cohort was analyzed. Concentrations of conjugated Neu5Ac were 35.1 ± 9.4 µg/mL and 33.0 ± 9.5 µg/mL in black and white participants, respectively. Conjugated and total Neu5Ac levels were significantly higher in women, with p-values of 0.029 and 0.026, respectively. The free forms of Neu5Ac were 594 ± 421 ng/mL and 439 ± 168 ng/mL in black and white participants, respectively. Similarly, conjugated and total ManNAc levels were higher in black participants, at 1.81 ± 0.81 µg/mL and 1.90 ± 0.83 µg/mL, compared to 1.32 ± 0.52 µg/mL and 1.41 ± 0.53 µg/mL in white participants (both cases, p < 0.001). Free ManNAc was 93.1 ± 36.2 ng/mL in black and 89 ± 20.2 ng/mL in white participants. Subjects with higher BMI tend to have higher free ManNAc (p = 0.041). Furthermore, older subjects tend to have higher free (p ≤ 0.001) and total (p = 0.045) ManNAc. The improved LC-MS/MS quantification method should facilitate further investigations. Full article

Background/Objectives: Flavonoids are widely used as lead structures in drug discovery, and their pharmacological and metabolic properties are strongly influenced by structural features such as positional isomerism. This study aimed to compare the metabolic profiles and underlying mechanisms of two isoflavone-based positional isomers, ACF-02 (2-(4-hydroxy-3-methoxyphenyl)-6,7-dimethoxy-3-(4-methoxyphenyl)-4H-chromen-4-one) and ACF-03 (2-(3-hydroxy-4-methoxyphenyl)-6,7-dimethoxy-3-(4-methoxyphenyl)-4H-chromen-4-one). Methods: The metabolic pathways of synthetically prepared ACF-02 and ACF-03 were investigated using an in vitro incubation system with human liver microsomes (HLMs) supplemented with an NADPH-regenerating system, followed by liquid chromatography–high-resolution tandem mass spectrometry (LC–HRMS/MS) analysis. Metabolites were identified based on LC–HRMS/MS data and molecular networking-based node connectivity with the parent compounds. Major metabolites were further characterized by CYP phenotyping using recombinant CYP450 isoforms, and the potential for drug–drug interactions of ACF-03 was evaluated using a CYP probe substrate cocktail approach. Results: HLM incubation of ACF-02 and ACF-03 produced both hydroxylated and O-demethylated metabolites, with O-demethylation as the predominant pathway; notably, the most abundant O-demethylated metabolite differed in an isomer-dependent manner, occurring at the B₂ ring for ACF-02 and at the A ring for ACF-03, with distinct CYP isoform involvement. Molecular networking supported the relationships between the parent compounds and their metabolites, and both compounds exhibited relatively high metabolic stability with limited CYP inhibition. Conclusions: Despite differing only in the position of a single methyl substituent, ACF-02 and ACF-03 exhibited distinct isomer-dependent metabolic profiles. These findings demonstrate that even subtle positional isomerism can significantly influence metabolic behavior and should be carefully considered during lead optimization and drug design. Full article

Somatic embryogenesis (SE) plays a pivotal role in the propagation and genetic improvement of coniferous trees; however, its efficiency is frequently limited by the reduced embryogenic potential of callus cultures. Here, we investigated the metabolic determinants underlying this phenomenon in Picea mongolica by conducting a comparative metabolomic analysis of embryogenic calli (EC) and non-embryogenic calli (NEC). We observed significant metabolic differences between EC and NEC using an integrated approach combining morphological observations and untargeted liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based metabolomics. EC exhibited increased central carbon metabolism, characterized by enhanced citrate cycle (TCA) flux, with significantly increased levels of the key TCA intermediates, citric acid and L-malic acid—18.8- and 3.6-fold higher, respectively, than those in NEC. Conversely, NEC displayed a divergent metabolic state, characterized by the accumulation of various amino acids and the activation of secondary metabolic pathways, especially alkaloid biosynthesis. These results indicate that embryogenic competence in P. mongolica is supported by a distinct metabolic program that prioritizes energy generation and efficient carbon-nitrogen allocation for biosynthetic processes. Conversely, the non-embryogenic state arises from a shift in metabolic resources toward secondary metabolism. These findings provide key metabolic insights and a theoretical basis for enhancing conifer SE systems. Full article

Mud loach (Misgurnus mizolepis) is a freshwater fish widely farmed in inland aquaculture owing to its nutritional value. However, failure to distinguish Chinese from Korean mud loach negatively affects the distribution economy and food safety regulation. Untargeted profiling was previously used to determine the origin of mud loaches, and N-acetylhistidine and anserine were selected as biomarker candidates. However, their quantitative verification and practical applicability for origin discrimination have not been thoroughly investigated. In this study, mud loaches of different geographical origins were analyzed using liquid chromatography-ultraviolet and liquid chromatography-tandem mass spectrometry to quantify the two metabolites, followed by statistical and receiver operating characteristic (ROC) analyses to evaluate their discriminative performance. Compared with Korean mud loaches, Chinese mud loaches showed significantly higher concentrations of both metabolites. The area under the curve values for N-acetylhistidine and anserine were 0.88 and 0.89, respectively, reflecting high sensitivity and specificity for discriminating between Korean and Chinese mud loaches. Cutoff values were established for reliably distinguishing the geographical origin of mud loaches. The established approach based on N-acetylhistidine and anserine can be used to determine the geographical origin of mud loach. Full article

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and fibromyalgia (FM) are debilitating disorders with overlapping symptoms such as chronic pain and fatigue. Dysregulation of the endogenous opioid system, particularly µ-opioid receptor function, may contribute to their pathophysiology. This study examined whether epigenetic modifications, specifically µ-opioid receptor 1 gene (OPRM1) promoter methylation, play a role in this dysfunction. Using a repeated-measures design, 28 ME/CFS/FM patients and 26 matched healthy controls visited the hospital twice within four days. Assessments included blood sampling for epigenetic analysis, a clinical questionnaire battery, and quantitative sensory testing (QST). Global DNA (hydroxy)methylation was quantified via liquid chromatography–tandem mass spectrometry, and targeted pyrosequencing was performed on promoter regions of OPRM1, COMT, and BDNF. ME/CFS/FM patients reported significantly worse symptom outcomes. No differences in global (hydroxy)methylation were found. Patients showed significantly higher OPRM1 promoter methylation, which remained after adjusting for symptom severity and QST findings. Across timepoints, OPRM1 methylation consistently correlated with BDNF Promoter I and Exon III methylation. This is, to the best of our knowledge, the first study examining OPRM1 methylation in ME/CFS/FM. Increased OPRM1 methylation in patients, independent of symptoms or pain sensitivity measures, supports the hypothesis of dysregulated opioidergic signaling in these conditions. Full article

Salivary cortisol is widely used to investigate stress–periodontitis interactions, but its measurement is affected by methodological limitations. Cortisone, the predominant salivary glucocorticoid, may offer analytical advantages, yet its role in periodontitis remains unexplored. This study evaluated salivary cortisone in relation to periodontal disease severity and compared its performance with cortisol. Sixty-seven periodontitis patients were classified as Stage I/II (n = 32) or Stage III/IV (n = 35). A comprehensive periodontal examination was performed, including FMPS, FMBS, PPD, CAL, BoP, and the BL/Age ratio. Unstimulated morning saliva samples were analyzed for cortisone and cortisol using liquid chromatography–tandem mass spectrometry, and for IL-1β and IL-6 using ELISA. Both cortisone and cortisol levels were significantly higher in Stage III/IV periodontitis (p = 0.014). Cortisone correlated strongly with cortisol (ρ = 0.523, p < 0.001) and was positively associated with IL-6 (ρ = 0.322, p = 0.008) and multiple clinical indicators of periodontal disease severity. ROC analysis showed comparable discriminatory performance for cortisone and cortisol (AUC = 0.675), with cortisone demonstrating higher specificity (94%) for Stage III/IV periodontitis. Our findings suggest that salivary cortisone performs similarly to cortisol and warrants further investigation as an alternative salivary glucocorticoid marker in periodontal research. Full article

Evaluating the activity of indoleamine 2,3-dioxygenase (IDO), the rate-limiting enzyme in tryptophan (Trp) metabolism, is important because IDO is involved in immune tolerance and drives the production of Trp metabolites implicated in psychiatric disorders and cancer. This study aimed to design and develop a novel fluorescent l-Trp derivative to fluorometrically monitor Trp-catabolizing enzyme activity via IDO. To evaluate IDO activity in vivo, 7-N,N-dimethylamino-2,1,3-benzoxadiazole (DBD), a fluorophore, was covalently bound at the 5-position of the indole ring in Trp to produce 5-DBD-l-Trp. An in vivo microdialysis (MD) study was conducted using the kidneys of Sprague–Dawley rats. Specifically, 5.0 μM 5-DBD-l-Trp in phosphate-buffered Ringer’s solution was infused into the rats, and the MD sample was analyzed via high-performance liquid chromatography with fluorescence detection. In the MD sample, two fluorescence peaks other than 5-DBD-l-Trp were observed during the 5-DBD-l-Trp infusion, and the main metabolite peak was proposed to be 5-DBD-kynurenine, verified by liquid chromatography-tandem mass spectrometry. The intensity of the fluorescent peak was significantly attenuated by co-infusion with an IDO inhibitor, 1-methyl-d-Trp. These results suggest that 5-DBD-l-Trp may be metabolized by renal IDO and can be used to evaluate IDO activity in vivo. Full article

To prepare and characterize low-bitter angiotensin-converting enzyme (ACE)-inhibitory peptides from sesame protein, a triple-enzyme hydrolysis system was optimized using mixture design and response surface methodology. The resulting hydrolysate was separated by ultrafiltration and medium-pressure chromatography, followed by identification through nano-liquid chromatography–electrospray ionization-tandem mass spectrometry. Finally, the mechanism of typical low-bitter ACE-inhibitory peptides was elucidated by molecular docking and molecular dynamics simulation. Results showed that the optimal enzyme activity ratio of 1:0.94:1.07 for Alcalase, trypsin, and Flavourzyme, combined with optimized hydrolysis conditions (E/S ratio of 126,793.03 nkat/g, pH 8.40, 4.82 h hydrolysis time, and 45 °C), resulted in a peptide yield of 93.19 ± 0.14%, ACE-inhibitory rate of 95.92 ± 0.23%, and bitter value of 3.15 ± 0.09. APQLGR and APWLR exhibited high ACE-inhibitory activity and minimal bitterness among the seventeen identified peptides. Although both peptides bound to the S1 pocket and Zn²⁺ catalytic site of ACE, APWLR exhibited an additional interaction with the S2 pocket. Both peptides were predicted to antagonize the bitter taste receptor T2R14 by forming stable complexes with key residues, but two complexes exhibited distinct mechanisms of stabilization. This work demonstrates a method for producing dual-functional peptides from sesame protein, paving the way for their application in functional foods. Full article

Mugwort (Artemisia princeps Pamp.) is a traditional herb widely used across East Asia; despite this, optimal processing methods to preserve its functional components and palatability have not been fully established. Thus, we aimed to, for the first time, systematically examine the effects of 16 processing methods that combine blanching (steaming or boiling), drying [freeze-drying (FD), mechanical drying, shade drying, or silica gel drying], and rolling on mugwort’s appearance, total polyphenol content (TPC), antioxidant activity, and sensory characteristics. Our results showed that steaming for ≥2 min followed by FD was the most effective method for maintaining a high TPC and a vibrant green color. In contrast, boiling with sodium bicarbonate preserved color but substantially reduced both TPC and chlorogenic acid (CGA) content compared with steaming. Sensory evaluation revealed that consumers consistently preferred steaming over other processing methods. Liquid chromatography–tandem mass spectrometry analysis revealed that prolonged drying induced CGA isomerization to neochlorogenic acid. Moreover, processing time substantially influenced CGA stability, while high TPC did not compromise mugwort flavor. Our findings imply that an optimized combination of steaming and FD maximizes both functional and sensory quality of mugwort, highlighting the potential of mugwort tea as a flavorful functional food. Full article

Background: Osteoarthritis (OA) is a prevalent degenerative joint disease often causing functional disability. Current therapies provide only temporary relief and can cause adverse effects that frequently result in pain and disability. Current pharmacological options offer only temporary symptom relief and may cause adverse effects. Piper sarmentosum (PS), a plant traditionally used for its medicinal properties, has demonstrated antioxidant and anti-inflammatory activities that may counteract OA-related degeneration. This study provides preliminary insight into the therapeutic potential of PS aqueous extract in human OA chondrocytes. Methods: Compounds in the PS aqueous extract were profiled using liquid chromatography–tandem mass spectrometry (LC-MS/MS). Primary human OA chondrocytes (HOCs) were treated with 0.5, 2, and 4 µg/mL of PS aqueous extract for 72 h. Key OA-related parameters were assessed, including anabolic markers (sulfated glycosaminoglycan (sGAG), collagen type II (COL II), aggrecan core protein (ACP), SRY-box transcription factor 9 (SOX9)), catabolic markers (matrix metalloproteinase (MMP) 1, MMP13, cyclooxygenase 2 (COX2)), oxidative stress (nitric oxide (NO) production, inducible NO synthase (iNOS) expression), and inflammatory responses (interleukin (IL) 6). Gene expression was quantified using qPCR, and protein levels were evaluated using the colorimetric method, immunocytochemistry, and Western blot. Results: A total of 101 compounds were identified in the extract, including vitexin, pterostilbene, and glutathione—bioactives known for antioxidant, anti-inflammatory, and chondroprotective functions. PS-treated chondrocytes maintain healthy polygonal morphology. PS aqueous extract significantly enhanced anabolic gene expression (COL2A1, ACP, SOX9) and sGAG production, while concurrently suppressing COX2 expression and NO synthesis. Additionally, PS aqueous extract reduced COX2 and iNOS protein levels, indicating inhibition of the NO signaling pathway. Catabolic activity was attenuated, and inflammatory responses were partially reduced. Conclusions: PS aqueous extract exhibits promising chondroprotective, antioxidant, and anti-inflammatory effects in human OA chondrocytes, largely through the suppression of NO-mediated catabolic signaling. The presence of multiple bioactive compounds supports its mechanistic potential. These findings highlight PS aqueous extract as a potential therapeutic candidate for OA management. Further ex vivo and in vivo studies are warranted to validate its efficacy and clarify its mechanism in joint-tissue environments. Full article