Sulfate Conjugates Research Articles

Comparative Pharmacokinetic Assessment of Curcumin in Rats Following Intratracheal Instillation Versus Oral Administration: Concurrent Detection of Curcumin and Its Conjugates in Plasma by LC-MS/MS.

To establish and validate an LC-MS/MS method for the simultaneous determination of curcumin (CUR) as well as its glucuronide conjugate (COG) and sulfate conjugate (COS) in rat plasma. The method was employed to evaluate and compare the pharmacokinetic behaviors of curcumin following oral and intratracheal administration in rats. Rat plasma samples were separated by chromatography on a C18 column after protein precipitation with acetonitrile. Gradient elution with a mobile phase of 0.5 mM ammonium acetate in acetonitrile was utilized. Mass spectrometry detection incorporated an electrospray ionization (ESI) source, multiple reaction monitoring (MRM), and dual-mode (positive and negative) scanning for quantitative analysis. A total of 12 SD rats were randomly divided into two groups and were orally (20 mg/kg) or intratracheally (10 mg/kg) administrated curcumin, respectively. CUR, COG, and COS concentrations in plasma were measured to assess pharmacokinetic disparities. The method demonstrated linearity within the ranges of 2-400 ng/mL for CUR and COS and 5-1000 ng/mL for COG. Intratracheal administration significantly elevated CUR plasma concentrations compared to oral administration. The exposure of COG was higher than COS following oral administration. Conversely, intratracheal administration resulted in markedly higher COS exposure, with no significant difference in COG exposure after dose normalization between oral and inhalation routes. The established LC-MS/MS method provides a reliable tool for the simultaneous measurement of CUR, COG, and COS in rat plasma, facilitating preclinical pharmacokinetic investigations. The study reveals distinct pharmacokinetic profiles for CUR following oral versus intratracheal administration, suggesting that inhalation may offer superior therapeutic efficacy.

Identification of chemical constituents and pharmacokinetic characteristics of Xiaoyan Tuire Granule in rats

Xiaoyan Tuire Granule is a type of Chinese patent medicine that has been proven effective in treating respiratory tract infections. However, while it has been successfully introduced into clinical use, more knowledge is still needed regarding its chemical components and pharmacokinetics. This study investigated the chemical profile in the medicine and rat plasma by ultra high-performance liquid chromatography coupled with Q Exactive hybrid quadrupole-orbitrap high-resolution accurate mass spectrometry (UHPLC-Orbitrap-MS/MS). Subsequently, it developed a validated ultra high-performance liquid chromatography coupled with quadrupole mass spectrometry (UHPLC-MS/MS) method for determining five components in rat plasma after oral administration of Xiaoyan Tuire Granule. As a result, a total of 106 constituents were inferred, including 9 terpenoids, 29 flavonoids, 33 organic acids, 12 phenylpropanoids and 23 other compounds. After administration, 86 compounds were inferred in rat plasma, including 73 prototypes and 13 metabolites. The metabolic pathways were primarily hydrogenation, glucuronic acid conjugation, sulfate conjugation, hydrolysis and methylation. The established method determined the contents of esculetin, esculin, isovitexin, caffeic acid and p-coumaric acid had a good separation, and all the legal verification met the requirements. The pharmacokinetic results indicate that the absorption rate of the five compounds in vivo was rapid, with a Tmax of less than 0.25 h, and the elimination rate was also fast, with a half-time (T1/2) ranging from 1.22 h to 2.19 h. It is worth noting that esculin and esculetin have similar half-time in vivo due to their structural similarities. Among these five compounds, the AUC0-∞ and MRT0-∞ of p-coumaric acid and esculetin were relatively higher, indicating higher exposure and longer residence time of both compounds in vivo. In conclusion, this paper researched the chemical constituents and pharmacokinetics of Xiaoyan Tuire Granule, which provided the reference for further study.

Characterization of the in vitro penetration and first-pass metabolism of genistein and daidzein using human and pig skin explants and Phenion full-thickness skin models.

OECD test guideline compliant skin penetration studies, which also comply with the SCCS basic criteria, are lacking for genistein and daidzein. Therefore, we have measured their penetration and metabolism using ex vivo explants of fresh (i.e., metabolically viable) pig skin, fresh and frozen human skin, and Phenion full-thickness (FT) models. Preliminary studies using fresh pig skin helped to define the optimal experimental conditions. The dermal absorption of 10nmoles/cm2 genistein and daidzein in ethanol was comparable in all four models. A first-pass metabolism in skin to glucuronide and sulfate metabolites was demonstrated for both chemicals in all models except frozen human skin. The main difference between fresh skin models was the overall extent of metabolism and the relative ratio of each metabolite, for example, much lower sulfate conjugates were formed in pig skin incubations. The extent of parent chemical metabolized and the contribution of the glucuronide pathway were relatively lower in PhenionFT models than in fresh human skin, possibly due to a higher penetration rate in this model and differences in the expression of functional metabolizing enzymes. When metabolism in human skin was abolished by freezing, more radiolabelled chemical remained in the skin tissue but the overall dermal absorption was unchanged. In conclusion, this initial characterization study showed that all models tested indicated that genistein and daidzein extensively penetrated the skin when applied to skin in ethanol. All fresh skin models produced the same metabolites, with the known species difference in the sulfation pathway demonstrated in pig skin.

Toxicokinetics of 2-ethylhexyl salicylate (EHS) and its seven metabolites in humans after controlled single dermal exposure to EHS

The chemical UV filter 2-ethylhexyl salicylate (EHS) is used in various personal-care products. The dermal and oral metabolism of EHS have already been targeted by different studies. However, toxicokinetic data after a single dermal exposure to EHS was missing. In our study, three volunteers were dermally exposed to a commercial EHS-containing sunscreen for 9 h with an application dose of 2 mg sunscreen per cm2 body surface area. The exposure was performed indoors, and sunscreen was applied on about 75% of the total skin area. Complete urine voids were collected over 72 h and eight blood samples were drawn from each subject. Urine samples were analyzed for EHS and seven known metabolites (5OH-EHS, 4OH-EHS, 2OH-EHS, 6OH-EHS, 4oxo-EHS, 5oxo-EHS, and 5cx-EPS) by online-SPE UPLC MS/MS. The peaks of urinary elimination occurred 10–11 h after application. The elimination half-lives (Phase 1) were between 6.6 and 9.7 h. The dominant urinary biomarkers were EHS itself, followed by 5OH-EHS, 5cx-EPS, 5oxo-EHS, and 4OH-EHS. 2OH-EHS, 6OH-EHS, and 4oxo-EHS were detected only in minor amounts. An enhanced analysis of conjugation species revealed marginal amounts of unconjugated metabolites and up to 40% share of sulfate conjugates for 5OH-EHS, 5oxo-EHS, and 5cx-EPS. The results demonstrated a delayed systemic resorption of EHS via the dermal route. Despite an extensive metabolism, the parent compound occurred as main urinary parameter. The delayed dermal resorption as well as the slow elimination of EHS indicate an accumulation up to toxicological relevant doses during daily repeated dermal application to large skin areas.

European and African-specific plasma protein-QTL and metabolite-QTL analyses identify ancestry-specific T2D effector proteins and metabolites.

Initially focused on the European population, multiple genome-wide association studies (GWAS) of complex diseases, such as type-2 diabetes (T2D), have now extended to other populations. However, to date, few ancestry-matched omics datasets have been generated or further integrated with the disease GWAS to nominate the key genes and/or molecular traits underlying the disease risk loci. In this study, we generated and integrated plasma proteomics and metabolomics with array-based genotype datasets of European (EUR) and African (AFR) ancestries to identify ancestry-specific muti-omics quantitative trait loci (QTLs). We further applied these QTLs to ancestry-stratified T2D risk to pinpoint key proteins and metabolites underlying the disease-associated genetic loci. We nominated five proteins and four metabolites in the European group and one protein and one metabolite in the African group to be part of the molecular pathways of T2D risk in an ancestry-stratified manner. Our study demonstrates the integration of genetic and omic studies of different ancestries can be used to identify distinct effector molecular traits underlying the same disease across diverse populations. Specifically, in the AFR proteomic findings on T2D, we prioritized the protein QSOX2; while in the AFR metabolomic findings, we pinpointed the metabolite GlcNAc sulfate conjugate of C21H34O2 steroid. Neither of these findings overlapped with the corresponding EUR results.

Identification and characterization of GSK-9089 metabolites through high resolution-mass spectrometry based in vitro and in vivo rat biological sample analysis

Estrogen related receptors (ERRs) agonist GSK-9089 (DY-131) reported to pose a potential in increasing exercise endurance. High resolution mass spectrometry (HRMS) based analysis has utmost importance in the detection, identification, or characterization of a molecule including its metabolites in human body. In this study, in vitro metabolism profile of GSK-9089 was investigated after incubation with liver microsomes and S9 fractions. Additionally, in vivo metabolites of the molecule were identified in plasma, urine, and faeces samples of rats. Structures of all the potential metabolites were revealed by employing an in silico tool and HRMS based analysis through data-dependent and data-independent mining strategies. Nine unknown metabolites of GSK-9089 have been identified which were found to be present in a trace amount in in vivo matrices. Most of the in vitro and in vivo phase I metabolites of the molecule were formed after imine bond hydrolysis followed by deamidation, oxidation, and N-oxidation. The molecule underwent phase II metabolism to generate more polar metabolites mainly through glucuronide, sulfate conjugation biotransformation reactions. The in vitro and in vivo metabolites of GSK-9089 could be useful to identify the abuse of this ERRs agonist in the future.

Comprehensive characterization of the in vitro and in vivo metabolites of xylocarpin H using UHPLC-Q-TOF-MS/MS

Xylocarpin H, a limonoid from the Xylocarpin granatum, exhibits significant biological activities, including antioxidant, antiviral, analgesic, hypnotic, antimalarial, and antidepressant effects, demonstrating considerable potential for drug development. However, few studies have been reported to identify and classify active metabolites responsible for such excellent biological activities. In this study, we utilized ultra high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UHPLC–Q–TOF–MS/MS) coupled with multiple data postprocessing techniques to rapidly identify in vivo and in vitro metabolites of xylocarpin H. Consequently, a total of 32 metabolites (23 in phase I and 9 in phase II) of xylocarpin H were detected both in rat feces, urine, bile, blood, intestinal flora, and rat and human liver microsomes. The metabolic pathways of xylocarpin H mainly involve hydrolysis, oxidation, reduction, addition, glucose conjugation, glucuronide conjugation, and sulfate conjugation. The metabolite M15 of xylocarpin H was synthesized by ester hydrolysis and its structure was determined by nuclear magnetic resonance spectroscopy. This study elucidates the metabolic pathways of xylocarpin H and provides insights into the origin of its pharmacological activity.

Characterization of active alkaloids and metabolites in rats after oral administration of Zuojin Pill using UHPLC-Q-TOF-MS combined with bioinformatics and molecular docking analyses

Zuojin Pill (ZJP), a traditional Chinese medicine prescription composed of Rhizoma Coptidis and Euodiae Fructus in the ratio of 6:1 (w/w), has been widely used for the treatment of gastric disorders. However, an in-depth understanding of in vivo metabolism and distribution profiles of protoberberine alkaloids (PBAs) and indole alkaloids (IDAs) in ZJP is lacking. In this study, a method using ultra-high performance liquid chromatography coupled with quadruple time-of-flight mass spectrometry (UHPLC-Q-TOF-MS) was developed to systematically screen the alkaloids and their metabolites in rat plasma and various tissues after oral administration of ZJP. Furthermore, bioinformatics and molecular docking analyses were conducted to elucidate the contribution of the alkaloids and metabolites enriched in the stomach to the therapeutic effect of ZJP on gastritis. A total of 33 compounds, including 7 prototype alkaloids and 26 metabolites, were chemically defined or tentatively identified in this work. The metabolic pathways of PBAs (hydroxylation, oxidation, reduction, demethylation, demethylenation, glucuronide conjugation, sulfate conjugation) and IDAs (hydroxylation, glucuronide conjugation) were revealed. Notably, 7 prototype alkaloids and 18 metabolites were detected in the stomach, indicating their propensity for gastric distribution. These alkaloids and metabolites showed strong affinities with the 7 hub targets associated with gastritis, such as CCR7, CXCR4, IL6, IFNG, CCL2, TNF, and PTPRC, and could be considered the potential active substances of ZJP for treating gastritis. In conclusion, this study clarified the gastric distribution propensity of PBAs and IDAs and their metabolites, as well as their favorable binding interactions with gastritis-related targets, which could provide essential data for the further study of the pharmacodynamic material basis and gastroprotective mechanism of ZJP.

Tyrosine phenol-lyase inhibitor quercetin reduces fecal phenol levels in mice.

Tyrosine phenol-lyase (TPL), which is expressed in intestinal bacteria, catalyzes the formation of phenol from the substrate L-Tyr. Bacterial metabolite phenol and the sulfate conjugate (phenyl sulfate) are known as a type of uremic toxins, some of which exert cytotoxicity. Therefore, pathologically elevated phenol and phenyl sulfate levels are strongly implicated in the etiology and outcome of uremia. In this study, we explored the inhibitory effects of dietary polyphenols on TPL-catalyzed phenol production using a TPL activity assay. Quercetin, one of the most popular polyphenols, exhibited the strongest inhibitory activity (Ki = 19.9 µM). Quercetin competitively inhibited TPL, and its activity was stronger than that of a known TPL inhibitor (Tyr analog; 2-aza-Tyr, Ki = 42.0 µM). Additionally, quercetin significantly inhibited phenol production in TPL-expressing bacterial cultures (Morganella morganii and Citrobacter koseri) and Tyr-rich (5%) diet-fed C57BL/6J mouse feces. Our findings suggest that quercetin is the most promising polyphenol for reducing phenol levels. Because quercetin has a low gastrointestinal absorption rate, TPL inhibition in the intestinal tract by quercetin may be an effective strategy for treating uremia.

An Efficient Integrated Strategy for Comprehensive Metabolite Profiling of Sakurasosaponin from Aegiceras corniculatum in Rats.

Sakurasosaponin, a primary bioactive saponin from Aegiceras corniculatum, shows potential as an anti-cancer agent. However, there is a lack of information on its in vivo metabolism. This study aims to profile the in vivo metabolites of sakurasosaponin in rat feces, urine, and plasma after oral administration. An efficient strategy using ultra-high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry was developed, which combined metabolic prediction, multiple mass defects filtering, and highresolution extracted ion chromatograms for rapid and systematic analysis. Firstly, a theoretical list of metabolites for sakurasosaponin was developed. This was done by considering the metabolic pathways of saponins. Next, the multiple mass defects filtering method was employed to identify potential metabolites in feces and urine, using the unique metabolites of sakurasosaponin as multiple mass defects filtering templates. Subsequently, a high-resolution extracted ion chromatogram was used to quickly determine the metabolites in rat plasma post-identification in feces and urine. Lastly, the analysis of accurate mass, typical neutral loss, and diagnostic ion of the candidate metabolites was carried out to confirm their structural elucidation, and metabolic pathways of sakurasosaponin in vivo were also proposed. In total, 30 metabolites were provisionally identified in feces, urine, and plasma. Analysis of metabolic pathways revealed isomerization, deglycosylation, oxidation, hydroxylation, sulfate conjugation, glucuronide conjugation, and other related reactions as the primary biotransformation reactions of sakurasosaponin in vivo. The findings demonstrate that the designed research strategy effectively minimizes matrix interference, prevents the omission of low-concentration metabolites, and serves as a foundation for the discovery of active metabolites of sakurasosaponin.

Comprehensive assessment of the UV-filter 2-ethylhexyl salicylate and its phase I/II metabolites in urine by extended enzymatic hydrolysis and on-line SPE LC-MS/MS

2-ethylhexyl salicylate (EHS) is used as a UV filter in personal-care products, such as sunscreen, to prevent skin damage through UV radiation. The application of EHS-containing products leads to systemic EHS absorption, metabolization and excretion. To measure EHS and its corresponding metabolite levels in urine, a comprehensive analytical procedure based on an extended enzymatic hydrolysis, on-line-SPE, and UPLC-MS/MS was developed. The method covers a large profile of seven metabolites (including isomeric structures) as well as EHS itself in a run time only of 18 min. Easy sample preparation, consisting of a 2-h hydrolysis step, followed by on-line enrichment and purification, add to the efficiency of the method. An update, compared to a previous method for the determination of EHS and metabolites in urine, is that, during hydrolysis, both glucuronide and sulfate conjugates are considered. The method was furthermore applied to urine samples after a real-life exposure scenario to EHS-containing sunscreen. The method is highly sensitive with limits of detection ranging from 6 to 65 ng/L. Moreover, it is characterized by good precision data, accuracy, and robustness to matrix influences. Application of the method to urine samples following dermal exposure to an EHS-containing sunscreen revealed EHS as the main biomarker after dermal exposure, followed by the major biomarkers 5OH-EHS, 5cx-EPS, 4OH-EHS and 5oxo-EHS. The expansion and optimization of this method decisively contributes to the research on the dermal metabolism of EHS and can be applied in exposure studies and for human biomonitoring.

Biofarmasetics and Pharmacokinetics Study Analysis of Paracetamol Excretion Through Urine and Saliva

The purpose of this study was to determine that Paracetamol, also known as acetaminophen, is a commonly used analgesic and antipyretic drug to relieve pain and reduce fever. The process of metabolism and elimination of paracetamol from the body is important to understand, especially in the context of the safe use of this drug. This study aims to analyze the biopharmaceutics and pharmacokinetics studies of paracetamol excretion through urine and saliva as important indicators in understanding the metabolic and elimination processes of this drug. Paracetamol is rapidly and efficiently absorbed through the gastrointestinal tract, reaches the highest concentration in plasma in a short time, and is dispersed throughout the body fluids. The metabolic process of paracetamol mainly occurs in the liver, through two main phases: oxidation and conjugation with glucuronic and sulfuric acids. Excretion of drugs and their metabolites can occur through urine and saliva, with the kidney as the main organ in the excretion process. Qualitative analytical methods were used in this study to identify paracetamol metabolite compounds in urine and saliva samples and to evaluate the metabolic pathways involved. Glucoronide, sulfate, and phenol conjugate assays were used to detect the presence of paracetamol metabolites in the samples. The assay results showed that urine was more effective in excreting paracetamol compared to saliva. In conclusion, this study provides a better understanding of the metabolic process and elimination of paracetamol from the human body through the analysis of biopharmaceutics and pharmacokinetics studies. These results are important for understanding the therapeutic effects and toxicity of paracetamol as well as for developing more effective and safe drug use management strategies.

Deconjugation potentials of natural estrogen conjugates in sewage and wastewater treatment plant: New insights from model prediction and on-site investigations

Natural estrogen conjugates play important roles in municipal wastewater treatment plant (WWTP), but their deconjugation potentials are poorly understood. This work is the first to investigate the relationships between the enzyme activities of arylsulfatase/β-glucuronidase and deconjugation potentials of natural estrogen conjugates. This work led to three important findings. First, the enzyme activity of β-glucuronidase in sewage is far higher than that of arylsulfatase, while their corresponding activities in activated sludge were similar. Second, a model based on β-glucuronidase could successfully predict the deconjugation potentials of natural estrogen glucuronide conjugates in sewage. Third, the enzyme activity of arylsulfatase in sewage was too low to lead to evident deconjugation of sulfate conjugates, which means that the deconjugation rate of estrogen sulfates can be regarded as zero. By comparing their theoretical removal based on enzyme activity and on-site investigation, it is reasonable to conclude that reverse deconjugation of estrogen conjugates (i.e., conjugation of natural estrogens to form conjugated estrogens) likely exist in WWTP, which explains well why natural estrogen conjugates cannot be effectively removed in WWTP. Meanwhile, this work provides new insights how to improve the removal performance of WWTP on natural estrogen conjugates. SynopsisThis work is the first to show how arylsulfatase/β-glucuronidase could affect deconjugation of natural estrogen conjugates and possible way to enhance their removal in wastewater treatment plant.

Perturbations in human bile acid profiles following drug-induced liver injury investigated using semitargeted high-resolution mass spectrometry.

Acetaminophen (APAP) overdose is the leading cause of acute liver failure (ALF) in North America. To investigate the effect of drug-induced liver injury (DILI) on circulating bile acid (BA) profiles, serum from ALF patients and healthy controls were analyzed using a semitargeted high-resolution mass spectrometry approach to measure BAs in their unconjugated and amidated forms and their glucuronide and sulfate conjugates. Human serum samples from 20 healthy volunteers and 34 ALF patients were combined with deuterated BAs and extracted, prior to liquid chromatography high-resolution tandem mass spectrometry analysis. A mix of 46 standards helped assign 26 BAs in human serum by accurate mass and retention time matching. Moreover, other isomers of unconjugated and amidated BAs, as well as glucuronide and sulfate conjugates, were assigned by accurate mass filtering. In vitro incubations of standard BAs provided increased information for certain peaks of interest. A total of 275 BA metabolites, with confirmed or putative assignments, were measured in human serum samples. APAP overdose significantly influenced the levels of most BAs, promoting glycine conjugation, and, to a lesser extent, taurine conjugation. When patient outcome was considered, 11 BAs were altered significantly, including multiple sulfated species. Although many of the BAs measured did not have exact structures assigned, several putatively identified BAs of interest were further characterized using in vitro incubations. An optimized chromatographic separation tailored to BAs of ranging polarities was combined with accurate mass measurements to investigate the effect that DILI has on their complex profiles and metabolism to a much wider extent than previously possible. The analysis of complex BA profiles enabled in-depth analysis of the BA metabolism perturbations in ALF, including certain metabolites related to patient outcomes.

Edaravone Oral Suspension: A Neuroprotective Agent to Treat Amyotrophic Lateral Sclerosis.

Amyotrophic lateral sclerosis (ALS) is characterized by loss of motor neurons due to degeneration of nerve cells within the brain and spinal cord. Early symptoms include limb weakness, twitching or muscle cramping, and slurred speech. As the disease progresses, difficulty breathing, swallowing, and paralysis can lead to death. Currently, there are no medications that cure ALS, and guidelines recommend treatments focused on symptom management. Intravenous (IV) edaravone was approved by the US Food and Drug Administration (FDA) in 2017 as a treatment to slow the progression of ALS. In May 2022, the FDA approved an oral suspension (ORS) formulation of edaravone. The mechanism of action of edaravone is not well defined. However, its neuroprotective effects are thought to result from antioxidant properties occurring through elimination of free radicals. Edaravone ORS (105 mg) has a bioavailability of 57% when compared with edaravone IV (60 mg). The ORS should be taken on an empty stomach in the morning, with water and no food or beverages, for 1 hour. Edaravone is bound to albumin (92%), has a mean volume of distribution of 63.1 L, a half-life of 4.5-9 hours, and a total clearance of 35.9 L/h after intravenous administration. Edaravone is metabolized into nonactive sulfate and glucuronide conjugates. The FDA approval was based on studies of the pharmacokinetics, safety, tolerability, and bioavailability of edaravone ORS. A phase III, global, multicenter, open-label safety study was conducted on edaravone ORS in 185 patients with ALS over 48 weeks. The most reported treatment-emergent adverse events were falls, muscular weakness, and constipation. Serious treatment-emergent adverse events included disease worsening, dysphagia, dyspnea, and respiratory failure. Oral edaravone is an ALS treatment that can be self-administered or administered by a caregiver, precluding the need for administration by a health care professional in an institutional setting.

Metabolic profiling of (poly)phenolic compounds in mouse urine following consumption of hull-less and purple-grain barley.

The present study attempted for the first time to investigate the metabolic fate of (poly)phenolic compounds provided by a hull-less and purple grain barley genotype biofortified in anthocyanins. Balb/c mice were supplemented either with standard purified diet (SD) or whole-grain barley supplemented diet (WGB) for six weeks. Subsequently, (poly)phenolic metabolites were determined in urine samples by UPLC-MS/MS, and the principal metabolic pathways were elucidated. Thirty-nine (poly)phenolics compounds were identified in WGB which were distributed between the free (58%) and bound (42%) fractions, encompassing anthocyanins, phenolic acids, flavan-3-ols and flavones. Upon WGB intake, forty-two (poly)phenolic metabolites were identified, predominantly comprising phase-II sulphate, glucuronide, and/or methylated conjugates, along with colonic catabolites. Noteworthy metabolites included peonidin-3-O-glucuronide, peonidin-3-O-6''-O-malonylglucoside, and peonidin-3-O-glucoside among anthocyanins; hydroxyphenylpropanoic acid-O-sulphate among phenolic acids; and 5-(3',4'-dihydroxyphenyl)-γ-valerolactone-O-sulphate among flavan-3-ols. Metabolites like phenylpropionic, phenylacetic, hydroxybenzoic, and hippuric acids were found in both WGB and SD groups, with higher levels after barley consumption, indicating both endogenous and polyphenolic metabolism origins. Overall, this study offers valuable insights into the metabolism of (poly)phenols in purple barley, setting the stage for future investigations into the health benefits linked to the consumption of purple grain barley.

Development and validation of a LC–MS/MS method for the quantification of phenolic compounds in human saliva after intake of a procyanidin-rich pine bark extract

Plant-derived phenolic compounds are regularly ingested as food compounds or as food supplements. Concentrations of individual compounds and metabolites are typically measured in serum or urine samples. This, however, allows no conclusion on the distribution into organs and tissues. An easily accessible biofluid is saliva. At this point, it was not clear yet, whether polyphenols circulating in the blood would be secreted or diffuse into saliva. The purpose of the present study was to develop and validate a method using liquid chromatography coupled to electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) for analysis of phenolic compounds in human saliva. Method validation for the quantification of taxifolin, ferulic acid, caffeic acid, gallic acid, para-coumaric acid, and protocatechuic acid and the gut microbial catechin metabolite δ-(3,4-dihydroxyphenyl)-γ-valerolactone (M1) in human saliva was performed according to current guidelines for bioanalytical method validation. The lower limit of quantification ranged from 0.82 ng/ml for M1 to 8.20 ng/ml for protocatechuic acid. The method was successfully applied to an authentic saliva sample of a volunteer after swallowing of procyanidin-rich pine bark extract capsules (dietary supplement Pycnogenol®). All polyphenols except ferulic acid were quantified at concentrations ranging from 1.20 ng/ml (M1) to 10.34 ng/ml (gallic acid). Notably, in contrast to serum samples, all phenolic compounds were present without sulfate or glucuronic acid conjugation in saliva, suggesting an enzymatic deconjugation, e.g., by a β-glucuronidase activity, during compound transfer from serum to saliva. Since M1 is only produced in the gut, its presence in saliva ruled out the possibility of sample contamination by phenolic compounds residing in the oral cavity after food intake. To the best of our knowledge, this is the first time that the gut microbiota-derived metabolite M1 has been detected in saliva. To further investigate the role of phenolic compounds in saliva, the described analytical method can be applied in clinical studies investigating the biodistribution of polyphenols and their metabolites.

Doping control approach: Identification of equine in vitro metabolites of voxelotor (GBT440), a hemoglobin S polymerization inhibitor.

Sickle cell disease, a debilitating genetic disorder affecting numerous newborns globally, has historically received limited attention in pharmaceutical research. However, recent years have witnessed a notable shift, with the Food and Drug Administration approving three innovative disease-modifying medications. Voxelotor, also known as GBT440, is a promising compound that effectively prevents sickling, providing a safe approach to alleviate chronic hemolytic anemia in sickle cell disease. It is a novel, orally bioavailable small molecule that inhibits hemoglobin S polymerization by enhancing oxygen affinity to hemoglobin. The investigation demonstrated that voxelotor led to an unintended elevation of hemoglobin levels in healthy individuals by increasing serum erythropoietin levels. Voxelotor and its metabolites in an in vitro setting utilizing equine liver microsomes were discussed. Plausible structures of the identified metabolites were inferred through the application of liquid chromatography in conjunction with high-resolution mass spectrometry. Under the experimental conditions, a total of 31 metabolites were detected, including 16 phase I metabolites, two phase II metabolites, and 13 conjugates of phase I metabolites. The principal phase I metabolites were generated through processes such as hydroxylation, reduction, and dissociation. The presence of glucuronide and sulfate conjugates of the parent drug were also observed, along with hydroxylated, reduced, and dissociated analogs. The data acquired will accelerate the identification of voxelotor and related compounds, aiding in the detection of their illicit use in competitive sports. It is crucial to emphasize that the metabolites detailed in this manuscript were identified through in vitro experiments and their detection in an in vivo study may not be guaranteed.

Pharmacokinetics of Edaravone Oral Suspension in Patients With Amyotrophic Lateral Sclerosis

Edaravone is a neuroprotective agent approved as an intravenous treatment for amyotrophic lateral sclerosis (ALS). The intravenous administration of edaravone places a burden on patients and there is a clinical need for oral agents for the treatment of ALS. This report aimed to assess the pharmacokinetics and safety of an edaravone oral suspension in patients with ALS after oral and percutaneous endoscopic gastrostomy (PEG) tube administration. Two single-dose, open-label phase 1 clinical studies were conducted. Edaravone oral suspension (105 mg of edaravone in 5 mL aqueous suspension) was administered orally and via PEG tube to 9 and 6 Japanese patients with ALS, respectively. Plasma and urinary pharmacokinetics of unchanged edaravone and its metabolites (sulfate and glucuronide conjugates) were determined. Safety was also evaluated. After reaching maximum plasma concentration, the mean plasma concentration-time of unchanged edaravone showed a triphasic elimination. Mean plasma concentration-time profiles of the metabolites were higher than those of unchanged edaravone. The mean urinary excretion ratios were higher for the glucuronide conjugate than for either unchanged edaravone or the sulfate conjugate. In patients administered edaravone orally, a single adverse event occurred (blood urine present), which was mild and improved without medical intervention. No adverse drug reactions or serious adverse events were reported. In patients administered edaravone via PEG tube, 5 treatment-emergent adverse events were reported in 3 patients; none were related to the study drug. No adverse drug reactions were reported. In patients with ALS, a single dose of edaravone oral suspension was well absorbed and mainly eliminated in urine as the glucuronide conjugate. No safety concerns emerged. Pharmacokinetics were similar to those previously reported in healthy participants following oral administration. This indicates that effective drug concentrations were achieved and edaravone can be successfully administered both orally and via a PEG tube in patients with ALS. ClinicalTrials.gov, NCT04176224 (oral administration) and NCT04254913 (PEG tube administration), www. gov.

Inhibition of xanthine oxidase-catalyzed xanthine and 6-mercaptopurine oxidation by luteolin, naringenin, myricetin, ampelopsin and their conjugated metabolites

Luteolin, naringenin, myricetin, and ampelopsin are abundant flavonoids in nature, and several dietary supplements also contain them at very high doses. After the peroral intake, flavonoids go through extensive presystemic biotransformation; therefore, typically their sulfate/glucuronic acid conjugates reach high concentrations in the circulation. Xanthine oxidase (XO) enzyme is involved in uric acid production, and it also takes part in the elimination of certain drugs (e.g., 6-mercaptopurine). The inhibitory effects of flavonoid aglycones on XO have been widely studied; however, only limited data are available regarding their sulfate and glucuronic acid conjugates. In this study, we examined the impacts of luteolin, naringenin, myricetin, ampelopsin, and their sulfate/glucuronide derivatives on XO-catalyzed xanthine and 6-mercaptopurine oxidations employing in vitro enzyme incubation assays and molecular modeling studies. Our major results/conclusions are the following: (1) Sulfate metabolites were stronger while glucuronic acid derivatives were weaker inhibitors of XO compared to the parent flavonoids. (2) Naringenin, ampelopsin, and their metabolites were weak inhibitors of the enzyme. (3) Luteolin, myricetin, and their sulfates were highly potent inhibitors of XO, and the glucuronides of luteolin showed moderate inhibitory impacts. (4) Conjugated metabolites of luteolin and myricetin can be involved in the inhibitory effects of these flavonoids on XO enzyme.