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Search Results (214)

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Journal = Metabolites
Section = Pharmacology and Drug Metabolism

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14 pages, 267 KiB  
Article
Impact of Short-Term Liraglutide Therapy on Non-Invasive Markers of Liver Fibrosis in Patients with MASLD
by Aleksandra Bołdys, Maciej Borówka, Łukasz Bułdak and Bogusław Okopień
Metabolites 2025, 15(8), 510; https://doi.org/10.3390/metabo15080510 - 31 Jul 2025
Viewed by 470
Abstract
Background/Objectives: Affecting close to one-third of the global population, metabolic dysfunction-associated steatotic liver disease (MASLD) is a highly prevalent chronic liver disorder linked to metabolic risk factors such as obesity and insulin resistance. Liver fibrosis is a key determinant of prognosis, and [...] Read more.
Background/Objectives: Affecting close to one-third of the global population, metabolic dysfunction-associated steatotic liver disease (MASLD) is a highly prevalent chronic liver disorder linked to metabolic risk factors such as obesity and insulin resistance. Liver fibrosis is a key determinant of prognosis, and its progression increases the risk of liver-related and overall mortality. This exploratory research evaluated the potential impact of a 3-month intervention involving dietary counseling and liraglutide therapy on liver fibrosis and related metabolic markers in patients with MASLD and obesity without diabetes. Methods: In this prospective, single-arm exploratory intervention, 28 adult patients with MASLD and obesity received structured dietary counseling and daily subcutaneous liraglutide for 12 weeks. Liver fibrosis was assessed using non-invasive indices (FIB-4, APRI, BARD, ELF) and transient elastography performed with the FibroScan® device (Echosens, Paris, France). Results: After 3 months, a significant reduction in liver stiffness (−7.14%, p < 0.05) and ELF score (from 6.71 to 6.63; −1.2%, p < 0.05) was observed. APRI (p = 0.06) and FIB-4 (p = 0.09) showed trends toward improvement, while the BARD score and AST/ALT ratio remained unchanged. Conclusions: Short-term liraglutide therapy combined with lifestyle modification may improve early-stage liver fibrosis in patients with MASLD and obesity, as indicated by reductions in liver stiffness and ELF score. These preliminary findings highlight the potential of advanced non-invasive fibrosis markers in monitoring treatment response. However, as an exploratory study, results should be interpreted with caution, and larger, long-term trials are needed to confirm these observations and evaluate efficacy in patients with more advanced fibrosis stages. Full article
17 pages, 4790 KiB  
Article
A Comparative Study Using Reversed-Phase and Hydrophilic Interaction Liquid Chromatography to Investigate the In Vitro and In Vivo Metabolism of Five Selenium-Containing Cathinone Derivatives
by Lea Wagmann, Jana H. Schmitt, Tanja M. Gampfer, Simon D. Brandt, Kenneth Scott, Pierce V. Kavanagh and Markus R. Meyer
Metabolites 2025, 15(8), 497; https://doi.org/10.3390/metabo15080497 - 23 Jul 2025
Viewed by 482
Abstract
Background/Objectives: The emergence of cathinone-based psychostimulants necessitates ongoing research and analysis of the characteristics and properties of novel derivatives. The metabolic fate of five novel cathinone-derived substances (ASProp, MASProp, MASPent, PySProp, and PySPent) containing a selenophene moiety was investigated in vitro and [...] Read more.
Background/Objectives: The emergence of cathinone-based psychostimulants necessitates ongoing research and analysis of the characteristics and properties of novel derivatives. The metabolic fate of five novel cathinone-derived substances (ASProp, MASProp, MASPent, PySProp, and PySPent) containing a selenophene moiety was investigated in vitro and in vivo. Methods: All compounds were incubated individually with pooled human liver S9 fraction. A monooxygenase activity screening investigating the metabolic contribution of eleven recombinant phase I isoenzymes was conducted. Rat urine after oral administration was prepared by urine precipitation. Liquid chromatography–high-resolution tandem mass spectrometry was used for the analysis of all samples. Reversed-phase liquid chromatography (RPLC) and zwitterionic hydrophilic interaction liquid chromatography (HILIC) were used to evaluate and compare the metabolites’ chromatographic resolution. Results: Phase I reactions of ASProp, MASProp, MASPent, PySProp, and PySPent included N-dealkylation, hydroxylation, reduction, and combinations thereof. The monooxygenase activity screening revealed the contribution of various isozymes. Phase II reactions detected in vivo included N-acetylation and glucuronidation. Both chromatographic columns complemented each other. Conclusions: All substances revealed metabolic reactions comparable to those observed for other synthetic cathinones. Contributions from isozymes to their metabolism minimized the risk of drug–drug interactions. The identified metabolites should be considered as targets in human biosamples, especially in urine screening procedures. RPLC and HILIC can both be recommended for this purpose. Full article
(This article belongs to the Special Issue Metabolite Profiling of Novel Psychoactive Substances)
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28 pages, 8123 KiB  
Article
Human Metabolism of Sirolimus Revisited
by Baharak Davari, Touraj Shokati, Alexandra M. Ward, Vu Nguyen, Jost Klawitter, Jelena Klawitter and Uwe Christians
Metabolites 2025, 15(7), 489; https://doi.org/10.3390/metabo15070489 - 20 Jul 2025
Viewed by 550
Abstract
Background: Sirolimus (SRL, rapamycin) is a clinically important mTOR inhibitor used in immunosuppression, oncology, and cardiovascular drug-eluting devices. Despite its long-standing FDA approval, the human metabolic profile of SRL remains incompletely characterized. SRL is primarily metabolized by CYP3A enzymes in the liver and [...] Read more.
Background: Sirolimus (SRL, rapamycin) is a clinically important mTOR inhibitor used in immunosuppression, oncology, and cardiovascular drug-eluting devices. Despite its long-standing FDA approval, the human metabolic profile of SRL remains incompletely characterized. SRL is primarily metabolized by CYP3A enzymes in the liver and intestine, but the diversity, pharmacokinetics, and biological activity of its metabolites have been poorly explored due to the lack of structurally identified standards. Methods: To investigate SRL metabolism, we incubated SRL with pooled human liver microsomes (HLM) and isolated the resulting metabolites. Structural characterization was performed using high-resolution mass spectrometry (HRMS) and ion trap MSn. We also applied Density Functional Theory (DFT) calculations to assess the energetic favorability of metabolic transformations and conducted molecular dynamics (MD) simulations to model metabolite interactions within the CYP3A4 active site. Results: We identified 21 unique SRL metabolites, classified into five major structural groups: O-demethylated, hydroxylated, didemethylated, di-hydroxylated, and mixed hydroxylated/demethylated derivatives. DFT analyses indicated that certain demethylation and hydroxylation reactions were energetically preferred, correlating with metabolite abundance. MD simulations further validated these findings by demonstrating the favorable orientation and accessibility of key sites within the CYP3A4 binding pocket. Conclusions: This study provides a comprehensive structural map of SRL metabolism, offering mechanistic insights into the formation of its metabolites. Our integrated approach of experimental and computational analyses lays the groundwork for future investigations into the pharmacodynamic and toxicodynamic effects of SRL metabolites on the mTOR pathway. Full article
(This article belongs to the Section Pharmacology and Drug Metabolism)
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14 pages, 1649 KiB  
Article
LC-MS-Based Untargeted Metabolic Profiling in Plasma Following Dapagliflozin Administration in Healthy Volunteers
by Hyeon Ji Kim, Jae Hwa Lee, Ji Seo Park, Jin Ju Park, Hae Won Lee, Heeyoun Bunch, Sook Jin Seong, Mi-Ri Gwon and Young-Ran Yoon
Metabolites 2025, 15(7), 484; https://doi.org/10.3390/metabo15070484 - 17 Jul 2025
Viewed by 494
Abstract
Dapagliflozin, a sodium-glucose cotransporter 2 inhibitor, treats type 2 diabetes by blocking renal glucose reabsorption and promoting urinary glucose excretion. This mechanism lowers blood glucose concentrations independently of insulin. The resulting caloric loss also contributes to weight reduction. Although these effects are well [...] Read more.
Dapagliflozin, a sodium-glucose cotransporter 2 inhibitor, treats type 2 diabetes by blocking renal glucose reabsorption and promoting urinary glucose excretion. This mechanism lowers blood glucose concentrations independently of insulin. The resulting caloric loss also contributes to weight reduction. Although these effects are well documented in patients with diabetes, their magnitude and underlying mechanisms in healthy individuals remain poorly understood. Background/Objectives: We investigated metabolic alterations after a single 10 mg dose of dapagliflozin in healthy adults with normal body-mass indices (BMIs) using untargeted metabolomics. Methods: Thirteen healthy volunteers completed this study. Plasma was collected before and 24 h after dosing. Untargeted metabolic profiling was performed with ultra-high-performance liquid chromatography–quadrupole time-of-flight/mass spectrometry. Results: Twenty-five endogenous metabolites were annotated; ten were putatively identified. Eight metabolites increased significantly, whereas two decreased. Up-regulated metabolites included phosphatidylcholine (PC) species (PC O-36:5, PC 36:3), phosphatidylserine (PS) species (PS 40:2, PS 40:3, PS 36:1, PS 40:4), lysophosphatidylserine 22:1, and uridine. Dehydroepiandrosterone sulfate and bilirubin were down-regulated. According to the Human Metabolome Database, these metabolites participate in glycerophospholipid, branched-chain amino acid, pyrimidine, and steroid-hormone metabolism. Conclusions: Dapagliflozin may affect pathways related to energy metabolism and homeostasis beyond glucose regulation. These data provide a reference for future investigations into energy balance and metabolic flexibility in metabolic disorders. Full article
(This article belongs to the Section Pharmacology and Drug Metabolism)
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15 pages, 972 KiB  
Article
Pharmacometabolomics Study of Sulfamethoxazole and Trimethoprim in Kidney Transplant Recipients: Real-World Metabolism and Urinary Excretion
by Marieke A. J. Hof, Hessel de Haan, Stepan Stepanovic, Stephan J. L. Bakker, Eelko Hak, Gérard Hopfgartner, Frank Klont and TransplantLines Investigators
Metabolites 2025, 15(7), 473; https://doi.org/10.3390/metabo15070473 - 11 Jul 2025
Viewed by 458
Abstract
Background/Objectives: The increased use of antibiotics is raising concerns about environmental contamination and antibiotic resistance, exemplified by the case of cotrimoxazole, a widely prescribed combination of sulfamethoxazole and trimethoprim. After oral administration and absorption, both drugs are excreted in their parent and [...] Read more.
Background/Objectives: The increased use of antibiotics is raising concerns about environmental contamination and antibiotic resistance, exemplified by the case of cotrimoxazole, a widely prescribed combination of sulfamethoxazole and trimethoprim. After oral administration and absorption, both drugs are excreted in their parent and metabolized forms, which is a factor that is commonly considered in environmental studies. Many studies, however, rely on pharmacokinetic data from drug developers, who mostly investigate drug metabolism in healthy male volunteers rather than in actual patient populations. Methods: We investigated the real-world metabolism and urinary excretion of cotrimoxazole in an LC-SWATH/MS-based pharmacometabolomics study of 149 kidney transplant recipients who took part in the TransplantLines Biobank and Cohort Study (NCT0327284). Results: Our study confirmed (as “putatively characterized compound classes”) the presence of all the expected metabolites, and we (putatively) identified several previously unreported metabolites, including glucuronide conjugates of both drugs and two isoxazole ring-opened variants of sulfamethoxazole. The relative metabolite profiles furthermore indicated that the active drug trimethoprim accounted for 75% of the total signal intensity. For sulfamethoxazole, its acetylated metabolite was the main metabolite (59%), followed by the active parent drug (17%) and its glucuronide (7%). Alongside trimethoprim, these substances could serve as analytical targets for environmental cotrimoxazole monitoring, given their abundance (all three substances), activity (parent drug), and/or back-transformation potential (both conjugated metabolites). The isoxazole ring-opened variants (2–3%) may also warrant attention, considering their (presumed) absolute excreted quantities and potential pharmacological activity. Conclusions: This study underscores the value of pharmacometabolomics in elucidating real-world metabolite profiles, and it provides novel insights into cotrimoxazole metabolism and excretion, with implications for environmental and clinical monitoring. Full article
(This article belongs to the Special Issue Drug Metabolism: Latest Advances and Prospects)
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30 pages, 2043 KiB  
Review
Berberine as a Bioactive Alkaloid: Multi-Omics Perspectives on Its Role in Obesity Management
by Bartłomiej Zieniuk and Magdalena Pawełkowicz
Metabolites 2025, 15(7), 467; https://doi.org/10.3390/metabo15070467 - 9 Jul 2025
Viewed by 888
Abstract
Berberine, a bioactive isoquinoline alkaloid derived from medicinal plants such as Berberis and Coptis species, shows significant promise for managing obesity and associated metabolic disorders. This review synthesizes evidence on its modulation of AMP-activated protein kinase (AMPK) signaling, gut microbiota composition, lipid metabolism, [...] Read more.
Berberine, a bioactive isoquinoline alkaloid derived from medicinal plants such as Berberis and Coptis species, shows significant promise for managing obesity and associated metabolic disorders. This review synthesizes evidence on its modulation of AMP-activated protein kinase (AMPK) signaling, gut microbiota composition, lipid metabolism, and adipokine networks, elucidating how these actions converge to suppress adipogenesis and improve insulin sensitivity. Metabolomic profiling reveals critical shifts in bile acid metabolism, short-chain fatty acid production, and mitochondrial function. Recent studies also highlight berberine’s anti-inflammatory effects and regulatory influence on glucose homeostasis. Despite its promise, challenges in oral bioavailability and drug interactions necessitate the development of advanced delivery strategies. We further discuss nanoformulations and multi-omics approaches, which integrate data from genomics, transcriptomics, proteomics, and metabolomics, provide new insights into berberine’s mechanisms, and may guide personalized therapeutic applications. While promising, further studies are needed to validate these findings in humans and translate them into effective clinical strategies. Full article
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12 pages, 1407 KiB  
Article
Amide Proton Transfer-Weighted MR Imaging and Signal Variations in a Rat Model of Lipopolysaccharide-Induced Sepsis-Associated Encephalopathy
by Donghoon Lee, HyunJu Ryu, Yeon Ji Chae, Hind Binjaffar, Chul-Woong Woo, Dong-Cheol Woo and Do-Wan Lee
Metabolites 2025, 15(7), 465; https://doi.org/10.3390/metabo15070465 - 9 Jul 2025
Cited by 1 | Viewed by 447
Abstract
Introduction: Sepsis-associated encephalopathy (SAE) is an acute brain dysfunction secondary to systemic infection, occurring without direct central nervous system involvement. Despite its clinical relevance, reliable biomarkers for diagnosing SAE and assessing its severity remain limited. This study aimed to evaluate the feasibility of [...] Read more.
Introduction: Sepsis-associated encephalopathy (SAE) is an acute brain dysfunction secondary to systemic infection, occurring without direct central nervous system involvement. Despite its clinical relevance, reliable biomarkers for diagnosing SAE and assessing its severity remain limited. This study aimed to evaluate the feasibility of amide proton transfer-weighted (APTw) chemical exchange saturation transfer (CEST) MRI as a non-invasive molecular imaging technique for detecting metabolic alterations related to neuroinflammation in SAE. Using a lipopolysaccharide (LPS)-induced rat model, we focused on hippocampal changes associated with neuronal inflammation. Materials and Methods: Twenty-one Sprague–Dawley rats (8 weeks old, male) were divided into three groups: control (CTRL, n = 7), LPS-induced sepsis at 5 mg/kg (LPS05, n = 7), and 10 mg/kg (LPS10, n = 7). Sepsis was induced via a single intraperitoneal injection of LPS. APTw imaging was performed using a 7 T preclinical MRI system, and signal quantification in the hippocampus was conducted using the magnetization transfer ratio asymmetry analysis. Results and Discussion: APTw imaging at 7 T demonstrated significantly elevated hippocampal APTw signals in SAE model rats (LPS05 and LPS10) compared to the control (CTRL) group: CTRL (−1.940 ± 0.207%) vs. LPS05 (−0.472 ± 0.485%) (p < 0.001) and CTRL vs. LPS10 (−0.491 ± 0.279%) (p < 0.001). However, no statistically significant difference was observed between the LPS05 and LPS10 groups (p = 0.994). These results suggest that APTw imaging can effectively detect neuroinflammation-related metabolic alterations in the hippocampus. Conclusion: Our findings support the feasibility of APTw CEST imaging as a non-invasive molecular MRI technique for SAE, with potential applications in diagnosis, disease monitoring, and therapeutic evaluation. Full article
(This article belongs to the Section Pharmacology and Drug Metabolism)
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20 pages, 2548 KiB  
Article
In Vitro Metabolism of Doping Agents (Stanozolol, LGD-4033, Anastrozole, GW1516, Trimetazidine) by Human Seminal Vesicle and Liver Fractions
by Johanna Sternberg, Insa Peters, Nana Naumann, Andreas Thomas and Mario Thevis
Metabolites 2025, 15(7), 452; https://doi.org/10.3390/metabo15070452 - 4 Jul 2025
Viewed by 495
Abstract
Background: In order to address complex scenarios in anti-doping science, especially in cases where an unintentional exposure of athletes to prohibited substances and a corresponding contamination of doping control samples at the collection event are argued, an understanding of tissue-specific drug metabolism is [...] Read more.
Background: In order to address complex scenarios in anti-doping science, especially in cases where an unintentional exposure of athletes to prohibited substances and a corresponding contamination of doping control samples at the collection event are argued, an understanding of tissue-specific drug metabolism is essential. Hence, in this study, the metabolic capacity of the seminal vesicle using in vitro assays was investigated. Methods: The aim was to assess whether selected doping-relevant substances—stanozolol, LGD-4033, GW1516, trimetazidine, and anastrozole—are metabolised in seminal vesicle cellular fractions (SV-S9) and how that metabolism compares to biotransformations induced by human liver S9 fractions (HL-S9). Liquid chromatography coupled to high-resolution/accurate mass spectrometry (LC HRAM MS) enabled the sensitive detection and identification of metabolites, revealing a limited metabolic activity of SV-S9. Results: For LGD-4033, GW1516, and trimetazidine, minor metabolic transformations were observed, whereas no metabolites of stanozolol or anastrozole were detected. Gene expression analysis using digital polymerase chain reaction (dPCR) confirmed transcripts of CYP2D6, CYP2E1, and CYP2C9 in SV-S9, though no enzymatic activity was detected. Gene expression and enzymatic activity in CYP3A4 and CYP1A2—major hepatic enzymes—were absent in SV-S9. Conclusions: Overall, these pilot study results suggest that the seminal vesicle has only a low capacity for xenobiotic metabolism, which translates into a limited role in the biotransformation of drugs and, hence, the metabolic pattern. Full article
(This article belongs to the Section Pharmacology and Drug Metabolism)
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22 pages, 2428 KiB  
Article
Assessment of Metabolic Alterations Induced by Halogenated Additives and Antifungal Activity of Extracts from the Endophytic Fungus Fusarium sp. Associated with Dizygostemon riparius (Plantaginaceae)
by Hilzimar de Jesus Freitas Sá, Anne Karoline Maiorana Santos, Adriano Souza Fonseca, Lourivaldo da Silva Santos, Josivan Regis Farias, Rosane Nassar Meireles Guerra, Edson Rodrigues-Filho, Gilmar Silverio da Silva, Cleydlenne Costa Vasconcelos, Alberto Jorge Oliveira Lopes and Antônio José Cantanhede Filho
Metabolites 2025, 15(7), 451; https://doi.org/10.3390/metabo15070451 - 4 Jul 2025
Viewed by 358
Abstract
Background/Objectives: Endophytic fungi are valuable sources of bioactive compounds with potential therapeutic applications. This study aimed to evaluate the antifungal activity of secondary metabolites produced by Fusarium sp. isolated from Dizygostemon riparius, with particular focus on the impact of culture medium [...] Read more.
Background/Objectives: Endophytic fungi are valuable sources of bioactive compounds with potential therapeutic applications. This study aimed to evaluate the antifungal activity of secondary metabolites produced by Fusarium sp. isolated from Dizygostemon riparius, with particular focus on the impact of culture medium supplementation with halogenated and metallic additives on metabolite production. Methods: The fungus was cultivated in standard Czapek medium and media supplemented with NH4Br or MnCl2. Methanolic extracts were obtained, fractionated, and chemically characterised via LC-ESI-HRMS. In vitro antifungal assays, including MIC and MFC determinations and biofilm inhibition tests, were performed against Candida albicans strains. In vivo toxicity and efficacy were assessed using Tenebrio molitor larvae. Results: Fifteen metabolites were annotated, including known antifungals such as fusaric acid and cyclosporin A. Fractions EMBr4 and EMC5 demonstrated fungicidal activity with MIC values close to fluconazole and significantly inhibited biofilm formation and maturation. In vivo, these fractions displayed low acute toxicity and improved survival in infected larvae, comparable to fluconazole treatment. Conclusions: The results indicate that culture medium modulation enhances the production of bioactive metabolites by Fusarium sp., leading to extracts with notable antifungal efficacy and safety. EMBr4 and EMC5 are promising candidates for further development as antifungal agents, particularly for targeting biofilm-associated Candida infections. These findings support the potential of endophytic fungi as sources of novel therapeutics and warrant further mechanistic and pharmacological investigations. Full article
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15 pages, 1477 KiB  
Article
Geopropolis from Melipona fasciculata Smith Accelerates Wound Healing in Diabetic Mice
by Aramys Silva Reis, Gabriel Carvalho de Souza, Guilherme Martins Gomes Fontoura, Luecya Alves de Carvalho Silva, Alberto Jorge Oliveira Lopes, Richard Pereira Dutra, Lucilene Amorim Silva, Rosane Nassar Meireles Guerra, Maria Nilce Sousa Ribeiro and Flávia Raquel Fernandes Nascimento
Metabolites 2025, 15(6), 413; https://doi.org/10.3390/metabo15060413 - 19 Jun 2025
Viewed by 768
Abstract
Background: Diabetic foot ulcers present a significant clinical challenge because of their high prevalence and severe complications. The need for innovative and accessible treatment options is critical. Owing to their medicinal properties, natural products, such as geopropolis, hold promise. However, the wound healing [...] Read more.
Background: Diabetic foot ulcers present a significant clinical challenge because of their high prevalence and severe complications. The need for innovative and accessible treatment options is critical. Owing to their medicinal properties, natural products, such as geopropolis, hold promise. However, the wound healing potential of the geopropolis of Melipona fasciculata, particularly in accelerating the healing of diabetic ulcers, remains unexplored. In this study, we evaluated the ability of the geopropolis of M. fasciculata to promote wound healing in diabetic mice. Methods: Geopropolis was collected, prepared as a hydroalcoholic extract, and formulated into a topical cream. Non-obese diabetic (NOD) mice with induced chronic wounds were treated with this cream daily, and wound healing was assessed through macroscopic measurements, histological analysis, cytokine quantification, and in silico molecular docking studies. Results: The results demonstrated that, compared with the control treatment, the geopropolis cream accelerated wound closure at all the analyzed time points (days 3, 7, and 14), reduced inflammatory infiltrates, and enhanced fibroblast proliferation and collagen deposition. These alterations were particularly pronounced in the final phase of healing, indicating an improvement in wound repair processes. These effects occurred without altering systemic cytokine levels, suggesting a localized treatment action. These results may be partially associated with the theoretical ability of beta-amyrin and cycloartenol to interact with human myeloperoxidase (MPO), as suggested by in silico docking analysis. Conclusions: Overall, the findings indicate that geopropolis cream could represent a viable alternative for managing diabetic ulcers, providing an effective means to enhance wound healing while remaining accessible to low-income populations. Full article
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15 pages, 1178 KiB  
Article
Comparison of the Metabolic Profiles Associated with Protonitazene and Protonitazepyne in Two Severe Poisonings
by Romain Magny, Thomas Schiestel, Aymen M’Rad, Bertrand Lefrère, Jean-Herlé Raphalen, Stanislas Ledochowski, Laurence Labat, Bruno Mégarbane and Pascal Houzé
Metabolites 2025, 15(6), 371; https://doi.org/10.3390/metabo15060371 - 5 Jun 2025
Viewed by 704
Abstract
Nitazenes represent an emerging class of new synthetic opioids characterized by a high-potency μ-opioid receptor (MOR) agonist activity. Background: We report two 20-year-old males who presented with severe neurorespiratory depression with typical opioid syndrome, but no opioid identification based on routine blood [...] Read more.
Nitazenes represent an emerging class of new synthetic opioids characterized by a high-potency μ-opioid receptor (MOR) agonist activity. Background: We report two 20-year-old males who presented with severe neurorespiratory depression with typical opioid syndrome, but no opioid identification based on routine blood and urine screening tests. The first patient recovered with supportive care, mechanical ventilation, and naloxone infusion, whereas the second patient developed post-anoxic cardiac arrest and died from brain death. Methods: A complementary comprehensive toxicological screening using liquid chromatography coupled with high-resolution mass spectrometry (LC-HRMS) was performed, and data were processed using a dedicated molecular network strategy to profile the metabolites. Results: Protonitazene and protonitazepyne, two nitazenes differing in their ethylamine moieties (i.e., a diethyl versus a pyrrolidine substitution, respectively), were identified. We found an extensive metabolism of protonitazene, leading to the identification of multiple phase I (resulting from hydroxylation, N-desethylation, and O-despropylation) and phase II (resulting from glucuronidation) metabolites. By contrast, protonitazepyne metabolism appeared limited, with one metabolite annotated confidently, protonitazepyne acid, which resulted from the oxidative pyrrolidine ring cleavage. Concusions: To conclude, nitazene detection is highly challenging due to its extensive structural and metabolic diversity. Our findings highlight the contribution of the untargeted LC-HRMS screening approach and suggest that diagnostic product ions can serve as robust markers for nitazene identification. Full article
(This article belongs to the Special Issue Metabolite Profiling of Novel Psychoactive Substances)
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12 pages, 1777 KiB  
Article
Comparison of Pyrazinamide with Isoniazid for Their Effects on the Heme Biosynthetic Pathway in Mouse Liver
by Fu-Ying Qin, Ruizhi Gu, Jiaojiao Zhang, Jaden Leigh Weiss, Jie Lu, Qing Ma and Xiaochao Ma
Metabolites 2025, 15(6), 355; https://doi.org/10.3390/metabo15060355 - 28 May 2025
Viewed by 531
Abstract
Background/Objectives: Isoniazid (INH) and pyrazinamide (PZA) are first-line drugs used to treat tuberculosis (TB), but their use is generally contraindicated in patients with porphyria, a group of metabolic disorders caused by defects in the heme biosynthetic pathway. To investigate the basis for these [...] Read more.
Background/Objectives: Isoniazid (INH) and pyrazinamide (PZA) are first-line drugs used to treat tuberculosis (TB), but their use is generally contraindicated in patients with porphyria, a group of metabolic disorders caused by defects in the heme biosynthetic pathway. To investigate the basis for these contraindications, we compared the effects of INH and PZA on the heme biosynthetic pathway in mouse liver. Method: We investigated the hepatic expression and activity of the key enzymes involved in the heme biosynthetic pathway, including aminolevulinic acid synthase 1 (Alas1) and ferrochelatase (Fech). Additionally, we employed a metabolomic approach to analyze liver and fecal samples from the mice treated with INH or PZA. Result: We found that INH, but not PZA, significantly upregulated the expression and activity of Alas1, the rate-limiting enzyme in heme biosynthesis, while concurrently downregulating Fech, which converts protoporphyrin IX (PPIX) to heme. These changes resulted in the accumulation of the toxic intermediate aminolevulinic acid (ALA) and PPIX in the liver of INH-treated mice. In contrast, PZA had no measurable effect on the expression or function of Alas1 or Fech. Conclusions: These findings provide mechanistic insight into INH-induced porphyria exacerbation and suggest that PZA may not carry the same risk, challenging its current contraindication. Full article
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18 pages, 11713 KiB  
Article
Compound 3d Attenuates Metabolic Dysfunction-Associated Steatohepatitis via Peroxisome Proliferator-Activated Receptor Pathway Activation and Inhibition of Inflammatory and Apoptotic Signaling
by Shouqing Zhang, Jiajia Yu, Sule Bai, Shuhan Li, Quanyuan Qiu, Xiangshun Kong, Cen Xiang, Zhen Liu, Peng Yu and Yuou Teng
Metabolites 2025, 15(5), 296; https://doi.org/10.3390/metabo15050296 - 29 Apr 2025
Viewed by 792
Abstract
Objectives: Metabolic dysfunction-associated steatohepatitis (MASH) lacks effective therapies. This study aimed to evaluate the therapeutic potential of compound 3d, a novel elafibranor derivative, focusing on its dual mechanisms of PPAR pathway activation and p38 MAPK signaling inhibition. Methods: Integrated in vitro and [...] Read more.
Objectives: Metabolic dysfunction-associated steatohepatitis (MASH) lacks effective therapies. This study aimed to evaluate the therapeutic potential of compound 3d, a novel elafibranor derivative, focusing on its dual mechanisms of PPAR pathway activation and p38 MAPK signaling inhibition. Methods: Integrated in vitro and in vivo approaches were employed. In vitro, free fatty acid (FFA)-induced lipid accumulation in L02 hepatocytes and lipopolysaccharides (LPSs)-stimulated inflammatory responses in RAW264.7 macrophages were used to evaluate lipid metabolism and anti-inflammatory effects. In vivo, a high-fat diet (HFD)-induced MASH model in C57BL/6 mice assessed serum biochemical parameters (triglycerides (TGs), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), alanine aminotransferase (ALT), aspartate transaminase (AST), tumor necrosis factor-α (TNF-α), nitric oxide (NO), and interleukin-6 (IL-6)), liver histopathology (H&E, Oil Red O, Masson staining), and proteomic profiling. Gut microbiota composition was analyzed via 16S rRNA sequencing. Western blotting quantified PPAR isoforms (γ/δ), downstream targets (Acox1, EHHADH, Acaa1), and p38 MAPK pathway proteins (p-p38, caspase-8, Bcl-2). Results: In vitro, 3d significantly reduced lipid accumulation (reduction in TG, p < 0.01) and inflammation (decrease in ALT activity, p < 0.05) in hepatocytes, while suppressing LPSs-induced TNF-α (63% reduction), NO (51% decrease), and IL-6 (48% reduction) in macrophages (p < 0.01). In vivo, 3d (30 mg/kg) lowered serum TG (39% decrease), TC (32% reduction), LDL-C (45% decline), and TNF-α (57% reduction) in HFD-fed mice (p < 0.05 vs. model), normalized AST/ALT levels, and ameliorated hepatic steatosis, ballooning, and fibrosis. Proteomics demonstrated PPARγ/δ activation (2.3–3.1-fold upregulation of Acox1, EHHADH, Acaa1; p < 0.001) and p38 MAPK pathway inhibition (54% reduction in p-p38, 61% decrease in caspase-8; 1.8-fold increase in Bcl-2; p < 0.01). Gut microbiota analysis revealed enrichment of beneficial taxa (Lactobacillus: 2.7-fold increase; Bifidobacterium: 1.9-fold rise) and reduced pathogenic Proteobacteria (68% decrease, p < 0.05). Conclusions: Compound 3d alleviates MASH via PPAR-mediated lipid metabolism enhancement and p38 MAPK-driven inflammation/apoptosis suppression, with additional gut microbiota modulation. These findings highlight 3d as a multi-target therapeutic candidate for MASH. Full article
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15 pages, 1583 KiB  
Article
Development and Application of an In-Capillary CE-DAD Method for the Inhibitory Screening of Natural Extracts Towards Acetylcholinesterase Enzyme
by Francesca Rinaldi, Sofia Salerno, Elena Frigoli, Giulia De Soricellis, Gloria Brusotti, Stefano Negri, Matteo Radice, Francesca Merlo, Andrea Speltini, Hellas Cena and Enrica Calleri
Metabolites 2025, 15(4), 283; https://doi.org/10.3390/metabo15040283 - 18 Apr 2025
Viewed by 499
Abstract
Background: The enzymatic activity of acetylcholinesterase (AChE) has been a focal point in neurodegenerative diseases research, particularly in relation to Alzheimer’s disease. This is attributed to the significantly reduced levels of cholinergic neurons observed in Alzheimer’s patients compared to healthy individuals. The strategy [...] Read more.
Background: The enzymatic activity of acetylcholinesterase (AChE) has been a focal point in neurodegenerative diseases research, particularly in relation to Alzheimer’s disease. This is attributed to the significantly reduced levels of cholinergic neurons observed in Alzheimer’s patients compared to healthy individuals. The strategy to mitigate the onset of these diseases in patients lies in the exploration of new potential AChE inhibitors with a focus also on natural extracts. A rapid and specific capillary electrophoresis method with direct ultraviolet detection (CZE-UV/Vis) was developed to screen natural extracts by assessing their potential to inhibit AChE. Materials and Methods: To enhance the specificity when analysing complex matrixes such as natural extracts, a sequential analysis approach based on the “sandwich model” was implemented using Ellman’s reagent [5,5′-dithiobis-(2-nitrobenzoic acid)] (DTNB) as a colorimetric indicator. Results: A reference inhibitor, neostigmine, was used for system validation through IC50 and Ki values determination by subsequent injections of acetylthiocholine substrate in the presence of neostigmine at increasing concentrations, and the enzyme combined with DTNB in borate-phosphate buffer (30 mM, pH 8.0). The enzymatic product was selectively detected at 412 nm. The validated system was applied to the analysis of seven natural extracts. Conclusions: Results demonstrated promising outcomes for identifying phytotherapeutic agents with potential applications in the prevention of neurodegenerative diseases. This method provides high selectivity and automation, offering a streamlined and effective approach for screening natural matrices containing potential AChE inhibitors. Full article
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14 pages, 4295 KiB  
Article
LC-MS/MS-Based Determination and Optimization of Linoleic Acid Oxides in Baijiu and Their Variation with Storage Time
by Cheng Fang, Xiaotong Zhuang, Zhanguo Li, Yongfang Zou, Jizhou Pu, Dong Wang and Yan Xu
Metabolites 2025, 15(4), 246; https://doi.org/10.3390/metabo15040246 - 2 Apr 2025
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Abstract
Background: Post-production storage plays a pivotal role in developing the characteristic flavor profile of Baijiu, a traditional alcoholic beverage in China. While aging markers remain crucial for quality authentication, the identification of reliable metabolic indicators for chronological determination requires further exploration. [...] Read more.
Background: Post-production storage plays a pivotal role in developing the characteristic flavor profile of Baijiu, a traditional alcoholic beverage in China. While aging markers remain crucial for quality authentication, the identification of reliable metabolic indicators for chronological determination requires further exploration. Methods: This study establishes a novel liquid chromatography-tandem mass spectrometry (LC-MS/MS) methodology for quantifying five linoleic acid-derived oxidative metabolites in Baijiu: 9,12,13-trihydroxy-10(E)-octadecenoic acid (9,12,13-TriHOME), 9,10-Dihydroxy-12-octadecenoic acid (9,10-DiHOME), 9-oxo-(10E,12Z)-octadecadienoic acid (9-OxoODE), 9-hydroxy-(10E,12Z)-octadecadienoic acid (9-HODE) and 13-hydroxyoctadeca-(9Z,11E)-octadecadienoic acid (13-HODE). Results: The optimized protocol demonstrated exceptional sensitivity with limits of detection at 0.4 ppb through membrane-filtered direct dilution. Calibration curves exhibited excellent linearity (R2 > 0.9990) across 1.0–100.0 ppb ranges. Method validation revealed satisfactory recovery rates (87.25–119.44%) at three spiking levels (10/20/50 ppb) with precision below 6.96% RSD. Application to authentic samples showed distinct temporal accumulation patterns. Light-aroma Baijiu exhibited storage duration-dependent increases in all five oxides. Strong aroma variants demonstrated significant positive correlations for 9,12,13-TriHOME, 9,10-DiHOME, and 9-OxoODE with aging time. Conclusions: These findings systematically characterize linoleic acid oxidation products as potential aging markers, providing both methodological advancements and new insights into Baijiu aging mechanisms. Full article
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