Ultra-performance Liquid Chromatography-tandem Mass Research Articles

An Investigation of Pharmacokinetic Interaction of Vericiguat with Apigenin based on a Newly Developed Ultra-performance Liquid Chromatography-tandem Mass Spectrometry Assay.

Vericiguat, as a new stimulator of soluble guanylate cyclase (sGC), was recently approved as a first-in-class treatment for reducing risks in patients with ejection fraction less than 45 percent and heart failure (HF) in the USA. The main aim of the present experiment was to establish an acceptable, sensitive assay based on ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) for quantitatively analyzing the plasma concentration levels of vericiguat in rats, and to further evaluate the effect of apigenin on the metabolism of vericiguat in vivo. In sample processes, acetonitrile was finally chosen for quickly precipitating protein. The levels of vericiguat in plasma were analyzed by a Xevo TQ-S triple quadrupole tandem mass spectrometry (Milford, MA, USA) in a positive ion mode. The scope of the calibration standard for vericiguat ranged from 0.5 to 1000 ng/mL, where a great linearity was acceptable. The lower limit of quantification (also called LLOQ) of vericiguat presented the sensitivity of this assay was evaluated as low as 0.5 ng/mL. Additionally, selectivity, accuracy and precision, extraction recovery, matrix effect, and stability were all verified. Subsequently, this approach also supported to assess the plasmatic concentrations of vericiguat from an interaction survey on herb-- drug, in which oral administration of apigenin (20 mg/kg) obviously increased the plasmatic levels of vericiguat and altered the pharmacokinetics of vericiguat in rats. These results would help us to further understand the pharmacokinetic properties of vericiguat when co-administration with apigenin, and to avoid unexpected clinical risks in the future.

In vivo evaluation of the pharmacokinetic interactions between almonertinib and rivaroxaban, almonertinib and apixaban.

Background: Almonertinib, a third-generation epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), is commonly used as a first-line treatment for non-small cell lung cancer (NSCLC) patients with EGFR T790M mutations. Rivaroxaban and apixaban are a selective, direct factor Xa inhibitor used to treat venous thromboembolism (VTE), which is a frequent complication of NSCLC. Rivaroxaban and apixaban are substrates of CYP3A4, P-gp and BCRP, whereas almonertinib is an inhibitor of P-gp and BCRP. Rivaroxaban or apixaban are often prescribed together with almonertinib in NSCLC patients, but clear information on pharmacokinetic drug interaction is lacking. Therefore, this study aimed to unravel the extent of interactions between almonertinib-rivaroxaban and almonertinib apixaban in rats, and whether the pharmacokinetic interaction can be mitigated by rivaroxaban and apixaban dose adjustment. Methods: Rats were divided into ten groups (n = 6) that received rivaroxaban (2mg/kg) (group 1), apixaban (0.5mg/kg) (group 2), almonertinib (15mg/kg) (group 3, group 4), almonertinib with rivaroxaban (2mg/kg) (group 5), almonertinib with rivaroxaban (1mg/kg) (group 6), almonertinib with apixaban (0.5mg/kg) (group 7), almonertinib with apixaban (0.25mg/kg) (group 8), rivaroxaban (2mg/kg) with almonertinib (group 9), apixaban (0.5mg/kg) with almonertinib (group 10). The concentrations of drugs were determined by an ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). The levels of messenger RNA were determined using quantitative real-time polymerase chain reaction (qRT-PCR). Results and Discussion: The results indicate that almonertinib increased the Cmax and AUC0-t of 2mg/kg rivaroxaban by 3.30 and 3.60-fold, 1mg/kg rivaroxaban by 1.28 and 1.90-fold. Almonertinib increased the Cmax and AUC0-t of 0.5mg/kg apixaban by 2.69 and 2.87-fold, 0.25mg/kg apixaban by 2.19 and 2.06-fold. In addition, rivaroxaban also increased systemic exposure to almonertinib. The results of qRT-PCR showed that almonertinib reduced the expression of Cyp3a1 in liver and intestine, and Abcb1a, Abcg2 in intestine and kidney. The pharmacokinetic results suggest that it is important to take special care of the interactions of these drugs in clinical applications.

Widely targeted metabolomics unveils baicalin-induced hippocampal metabolic alternations in a rat model of chronic unpredictable mild stress

Baicalin has various neuroprotective effects in models of nervous system disease. Our study has shown baicalin could alleviate depressive-like behaviors in a neuroendocrine mouse model. But the systematic metabolic characteristic and particular targets of baicalin in regulating depressive behaviors have never been investigated. Therefore, this study aims to reveal the hippocampal metabolic profiling of chronic unpredictable mild stress (CUMS) induced depressive rats and the potential metabolic variations after baicalin treatment. We first used the sucrose preference test and open field test to access the antidepressant effects of baicalin. Then, metabolites of the hippocampus after baicalin therapy were monitored by widely-targeted metabolomics based on ultra-performance liquid chromatography-tandem mass spectrometry technology. Finally, the potential mechanism associated with neurogenesis obtained from metabolomics was verified by immunohistochemistry. The results showed that baicalin(40,80 mg/kg) could significantly alleviate depressive behaviors induced by CUMS as demonstrated by an increase in sucrose preference and movement distance and stand-up times in open field test. In the metabolomic analysis, a total of 733 metabolites were identified after baicalin treatment including 15 differential metabolites such as organic acid and its derivatives, heterocyclic compounds, fatty acid, bile acids, amino acid and its metabolites, and so on. Enrichment for differential metabolites showed that the differential metabolites might be involved in the process of folate and cofactor biosynthesis, cholesterol metabolism, primary bile acid biosynthesis, tyrosine metabolism and dopaminergic synapse. Moreover, immunohistochemical analysis confirmed baicalin could facilitate hippocampal neurogenesis of depressive rats in CUMS model. These results suggested baicalin might exert antidepressant effects through regulating the differential metabolites which might play a crucial role in inhibiting oxidative stress and improving neurogenesis. Our findings wish to discover the potential mechanism of baicalin on depression from the metabolomics perspective and promote its clinical application.

Ultra-Performance Liquid Chromatography with Tandem Mass Spectrometry for Simultaneous Analysis of 22 Analytes of Oncheong-Eum, a Traditional Korean Herbal Formula

Oncheong-eum (OCE) is a traditional Korean herbal formula comprising eight medicinal herbs for treating skin disorders, including eczema and skin rashes. Here, we sought to simultaneously analyze 22 analytes of OCE using ultra-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS). All analytes were separated on a Waters Acquity UPLC BEH C18 column (2.1 mm × 100 mm, 1.7 μm) maintained at 45 °C by gradient elution with a mobile phase of 0.1% (v/v) aqueous formic acid–acetonitrile. By applying a multiple reaction monitoring method, we rapidly determined the various analytes simultaneously. The coefficient of determination of the regression equation prepared in the tested concentration range of each authentic reference standard was ≥0.9950 and showed good linearity. The accuracy ranged from 84.23% to 115.47%, and the relative standard deviation values for intra- and interday precisions ranged from 0.84% to 9.57%, respectively. Analysis of OCE samples using this method showed that they contained up to 27.10 mg/g of active ingredients. The method can provide data to improve the consistency and, thus, the future quality of OCE preparations and other traditional herbal formulas.

Click Chemoselective Probe with a Photoswitchable Handle for Highly Sensitive Determination of Steroid Hormones in Food Samples.

Residues of endocrine disrupting steroid hormones in food might cause various diseases like cardiovascular diseases and breast and prostate cancers. Monitoring steroid hormone levels plays a vital role in ensuring food safety and exploring the pathogenic mechanism of steroid hormone-related diseases. Based on the Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) click reaction, a novel chemoselective probe, Azo-N3, which contains a reactive site N3, an imidazolium salt-based MS tag, and an azobenzene-based photoswitchable handle, was designed and synthesized to label ethynyl-bearing steroid hormones. The probe Azo-N3 was applied for the highly selective and sensitive detection of four ethynyl-bearing steroid hormones in food samples (milk, egg, and pork) by using ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The ionization efficiency of the labeled analytes could be increased by 6-105-fold, and such a labeled method exhibited satisfactory detection limits (0.04-0.2 μg/L), recovery (80.6-122.4%), and precision (RSDs% lower than 6.9%). Interestingly, the efficient immobilization of the probe Azo-N3 onto α-cyclodextrin (α-CD)-modified magnetic particles to construct a solid supported chemoselective probe Fe3O4-CD-Azo-N3 and UV light-controlled release of the labeled analytes from a magnetic support can be achieved by taking advantage of the photoswitched host-guest inclusion between the azobenzene unit and α-CD. The potential applications of Fe3O4-CD-Azo-N3 for labeling, capturing, and the photocontrolled release of the labeled steroid hormones were fully investigated by mass spectrometry imaging analysis. This work not only provides a sensitive and accurate method to detect steroid hormones in food but also opens a new avenue in designing solid supported chemoselective probes.

Optimization and validation of an oxidation and solid-phase extraction procedure for analysis of imidacloprid and its metabolites in cereals using ultra-performance liquid chromatography tandem mass spectrometry

A simple and reliable ultraperformance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method was proposed for analysis of the total residues of imidacloprid and its 6-chloropyridinyl metabolites in cereals. The method consisted of extraction with acidic acetonitrile, conversion of the analytes into 6-chloronicotinic acid by oxidation, cleanup with C18 cartridges, and UPLC-MS/MS detection. The validation results met the requirements of the guidelines for the detection of pesticide residues in EU and China, including the linearity (R2 = 0.998), matrix effect (−0.5∼-7.1%), accuracy (75.1–109.6%), precision (3.5–13.0%), metabolite conversion efficiency (81.6–102.3%), and sensitivity (limit of detection (LOD) of 0.0015 mg/kg and limit of quantification (LOQ) of 0.0050 mg/kg). The established method met the requirements of the residue definition and the maximum residue levels (MRLs) of imidacloprid in cereals, and was further applied to investigate the residues and dissipation of imidacloprid and its metabolites in wheat samples after field application.

Preparation of sulfonic acid functionalized covalent organic framework solid phase microextraction fibers and their application in the analysis of neurotransmitters in the mouse brain

Neurotransmitters (NTs) are essential for intercellular communication and primarily include monoamine, amino acid, and cholinergic NTs. These molecules play important roles in the body's stress response, motor coordination, neuronal communication, and homeostatic functions. Previous studies have shown that abnormal changes in NT levels are associated with various neurological disorders. Therefore, the development of accurate analytical methods for NT detection will enhance the current understanding on complex neuropathophysiology by providing functional knowledge and techniques for early diagnosis, thereby facilitating the development of new therapeutic options for the related diseases. The solid phase microextraction (SPME) technique combines sample preparation, separation, and enrichment in a single step and is minimally invasive, low cost, solvent free, and high throughput. SPME has been successfully applied to the in vivo analysis of target analytes in animal, human, and plant tissues. The coating material plays a significant role in the development of in vivo SPME methods and must meet various analytical requirements, including a suitable geometry for the SPME device, high extraction capacity, excellent selectivity, and wide extraction coverage for the target analytes. Covalent organic frameworks (COFs) are porous crystalline polymers constructed from organic framework units through strong covalent bonds; these materials are characterized with a low density, large specific surface area, permanent porosity, excellent chemical/thermal stability, and easy functionalization.In this study, a sulfonic acid-functionalized COF material (COF-SO3H) with good crystallinity, excellent chemical/thermal stability, strong hydrophobicity, a uniform mesoporous structure, and narrow pore size distribution was prepared using 2,4,6-triformylphloroglucinol and 1,4-diamino-2-nitrobenzene as monomers. Then, the COF-SO3H was coated onto the surface of stainless-steel fibers and used for in vivo enrichment of NTs. The structural properties of COF-SO3H were characterized using various techniques, such as scanning electron microscopy (SEM), Fourier transform-infrared spectroscopy (FT-IR), and X-ray diffraction (XRD), all of which showed that COF-SO3H had a good crystalline structure and uniform mesopore distribution with a specific surface area of 46.17 m2/g. Compared with the SPME fibers of HLB, C18, MCX, amino, and PXC columns, the prepared COF-SO3H fibers showed better extraction efficiency for the target NTs. Next, the factors affecting SPME efficiency were optimized. The optimal desorption solvent was formic acid-methanol-water (0.5∶49.5∶50, v/v/v), and the optimal extraction and desorption times were 15 min. A method for the in vivo analysis of NTs in the brains of mice was established by combining the COF-SO3H fibers with ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) under optimal conditions. The NTs were separated on an Acquity UPLC BEH-C18 analytical column (100 mm×2.1 mm, 1.7 μm) with 0.1% formic acid aqueous solution (A) and acetonitrile (B) as the mobile phases. The flow rate was set to 0.2 mL/min, and the gradient elution procedure was as follows: 0-4 min, 5%B-6%B; 4-7 min, 6%B-5%B; 7-11 min, 5%B. Under optimal conditions, the method showed good linearity (r2>0.99). The limits of quantification (S/N≥5) were in the range of 0.003-0.005 μg/mL and 3-5 μg/mL for monoamine and amino acid NTs, respectively, with RSDs of less than 20%. The method showed good precision (0.80%-9.70%) and accuracy (2.08%-17.72%), with absolute matrix effects in the range of 82.22%-117.92%. These values reflect the good purification and enrichment abilities of the proposed fibers for the target analytes. Finally, the established SPME method was combined with UPLC-MS/MS and successfully applied to quantify target NTs in the brains of mice. The proposed strategy provides a practical method for the in vivo detection and quantitative analysis of NTs and expands the applications of functionalized COF materials for the analysis of various targets.

Comparison of Crude and Wine-Steamed Corni Fructus Based on UPLC-Q-TOF-MS Combined With Pharmacodynamics Screening

Introduction: The dry ripe sarcocarp of Cornus officinalis Sieb.et Zucc (in Chinese Shanyurou) has the properties of tonifying the liver and kidney. Wine-steamed Corni Fructus, as the main processed product from Corni Fructus, is widely used in traditional Chinese clinical medicine. This article aims to study the Corni Fructus composition changes when wine-steamed processed and to discuss the optimal processing technology of Corni Fructus combined with pharmacological experiments. Methods: The differences between Corni Fructus and wine-steamed Corni fructus constituents were analyzed by ultra-performance liquid chromatography-tandem mass spectrometry. The effects of Corni Fructus and wine-steamed Corni Fructus with different processing times were studied from the aspects of immune activity, liver protection, and kidney yin deficiency. Results: A total of 132 compounds were identified in the wine-steamed process of Corni Fructus. There were no significant differences in immune function, liver protection, and kidney yin deficiency of Corni Fructus with different processing times. However, the effects of Corni Fructus processed by wine-steaming were significantly enhanced in all aspects. Conclusion: The wine-steamed Corni Fructus chemical composition may be the material basis for enhancing liver and kidney function. After processing, Corni Fructus can enhance immune function, liver protection function, and liver and kidney toning function.

Analytical strategies based on untargeted and targeted metabolomics for the accurate authentication of organic milk from Jersey and Yak.

Organic milk has a high risk of food fraud as it can easily be adulterated with non-organic milk. This study aimed to identify metabolite markers for assessing the authenticity of organic milk from Jersey and Yak. In the untargeted strategy, ultra-high performance liquid chromatography-Q Exactive HF-X mass spectrometer coupled with chemometrics analysis was used to screen and identify tentative markers of organic milk from Jersey and Yak. In the targeted strategy, a quick and easy method of ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed to quantify three markers. The peptide of Thr-Ala-Val and D-biotin were determined to be metabolite markers for distinguishing organic and non-organic Jersey milk, whereas trimethylamine N-oxide was determined to be a metabolite marker for distinguishing organic and non-organic Yak milk. These findings provide critical information to facilitate assessments of organic milk authenticity.

Effects of fecal microbiota transplantation for recurrent Clostridium difficile infection in children on kidney replacement therapy: a pilot study.

Recurrent Clostridium difficile infection (rCDI) is a rising problem in children with chronic diseases. Fecal microbiota transplantation (FMT) is a recent alternative for rCDI patients who do not respond to conventional treatment. FMT could have an additional positive effect on the intestinal dysbiosis and accumulation of uremic retention molecules (URM) associated with chronic kidney disease (CKD). Our aim was to investigate the clinical efficacy of FMT for rCDI in children with CKD together with the effect on dysbiosis and URM levels. We analyzed stool and blood samples before and until 3months after FMT in 3 children between 4 and 8years old with CKD and rCDI. The microbiome was analyzed by 16s rRNA sequencing. URM were analyzed with ultra-performance liquid chromatography-tandem mass spectrometry. CRP and fecal calprotectin were analyzed as parameters for systemic and gut inflammation, respectively. CDI resolved after FMT in all three without adverse events; one patient needed a second FMT. No significant effect on CRP and calprotectin was observed. Stool samples demonstrated a reduced richness and bacterial diversity which did not improve after FMT. We did observe a trend in the decrease of specific URM up to 3months after FMT. FMT is an effective treatment for rCDI in patients with CKD. Analysis of the microbiome showed an important intestinal dysbiosis that, besides a significant reduction in Clostridium difficile, did not significantly change after FMT. A trend for reduction was seen in some of the measured URM after FMT.

Effect of Lactobacillus acidophilus fermentation on bioaccessibility: The relationship between biotransformation and antioxidant activity of apple polyphenols based on metabolomics

Apple (Malus domestica) polyphenols are strong antioxidants. However, the functional properties of apple polyphenols are limited due to their considerable low digestibility. Therefore, in this study, the effects of fermentation of apple pulp by Lactobacillus acidophilus on its total polyphenol content and antioxidant activity were assessed using metabolomics. The results showed that the total polyphenol content and antioxidant activity of apple pulp fermented with L. acidophilus zrx02 were significantly higher than those in the unfermented apple pulp. Six different significantly changed metabolites, including caffeic acid, hypericin, p-coumaric acid, p-hydroxybenzoic acid, ferulic acid, and eugenic acid, were selected using ultra-performance liquid chromatography-tandem mass spectrometry and a metabolomics analysis. A cluster analysis revealed that one group contained caffeic acid, while the other one contained ferulic acid, p-hydroxybenzoic acid, p-coumaric acid, hypericin, and syringic acid. Ten metabolic pathways with significant differences were screened using the hypergeometric method. Overall, the results suggest that after fermentation by L. acidophilus zrx02, apple polyphenols can be biotransformed into small molecules that are easily digested and absorbed, and they have improved antioxidant activity. It is a raw material source of antioxidant-rich active substances that merits full utilization.

B-174 Simple and Accurate Quantification of Four Direct Oral Anticoagulants in Plasma Using UPLC-MS/MS

Abstract Background Direct oral anticoagulants (DOACs) constitute first-line therapy used for many thromboembolic indications, such as prevention and treatment of venous thromboembolism and stroke prevention in atrial fibrillation. This class of medication consists of the direct thrombin inhibitor (dabigatran) or direct factor Xa inhibitors (apixaban, rivaroxaban, and edoxaban). DOACs quantification may be useful in the case of critical clinical situations, including drug accumulation in long-term treatment, overdosage, thrombotic or bleeding events. This study aimed to develop and validate an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for the quantification of four DOACs: dabigatran, apixaban, rivaroxaban, and edoxaban in plasma. Methods The calibration curve samples were prepared by spiking drug free plasma with DOACs. The stable isotope labeled DOACs was used as an internal standard. After addition of the internal standard and protein precipitation, the supernatant was 10-fold diluted and injected into a chromatography system consisting of a UPLC BEH C18 (2.1 × 50 mm; particle size 1.7 µm) analytical column with gradient made of mobile phase (5 mM ammonium formate pH3.5 in water and methanol). The outlet of the column was connected to a triple quadrupole mass spectrometer with electrospray interface. Ions were detected in the positive multiple reaction monitoring mode. The concentration of analyte was calculated from the calibration curve and ion ratios between the analyte and the internal standard. Results The analytical range was linear with a correlation coefficient of over 0.99 in the range of 0–500 ng/mL for each analyte. Intra- and inter-assay imprecision were less than 3.1% (n = 20) and 6.0% (n = 20), respectively. The accuracy was evaluated by spike recovery and the mean recoveries were between 97.2% and 102.1% for all analytes. This assay showed no ion suppression or enhancement and no carryover. The chromatography run time was 4.5 min. The assay was applied to quantitate DOACs in plasma samples from 93 patients. Our data showed that the DOACs concentrations vary markedly individual patients after equal dose, this therapeutic drug monitoring of DOACs is essential to optimized drug efficacy. Conclusion An accurate, and cost-effective UPLC-MS/MS method for the quantification of DOACs was successfully applied for therapeutic drug monitoring in patients.

Determine the enzymatic kinetic characteristics of CYP3A4 variants utilizing artemether-lumefantrine

Artemether-lumefantrine is an artemisinin-based combination therapy for the treatment of malaria, which are primarily metabolized by cytochrome P450 3A4. Therapeutic difference caused by gene polymorphisms of CYP3A4 may lead to uncertain adverse side effects or treatment failure. The aim of this study was to evaluate the effect of CYP3A4 gene polymorphism on artemether-lumefantrine metabolism in vitro. Enzyme kinetics assay was performed using recombinant human CYP3A4 cell microsomes. The analytes, dihydroartimisinin and desbutyl-lumefantrine, were detected by ultra-performance liquid chromatography tandem mass spectrometry. The results demonstrated that compared to CYP3A4.1, the intrinsic clearance of CYP3A4.4, 5, 9, 16, 18, 23, 24, 28, 31–34 significantly reduced for artemether (58.5%–93.3%), and CYP3A4.17 almost loss catalytic activity. Simultaneously, CYP3A4.5, 14, 17, 24 for lumefantrine were decreased by 56.1%–99.6%, and CYP3A4.11, 15, 18, 19, 23, 28, 29, 31–34 for lumefantrine was increased by 51.7%–296%. The variation in clearance rate indicated by molecular docking could be attributed to the disparity in the binding affinity of artemether and lumefantrine with CYP3A4. The data presented here have enriched our understanding of the effect of CYP3A4 gene polymorphism on artemether-lumefantrine metabolizing. These findings serve as a valuable reference and provide insights for guiding the treatment strategy involving artemether-lumefantrine.

Pharmacokinetic profiles and egg residue patterns of levamisole in laying hens at two dosing rates and two routes of administration

The levamisole maximum residue limit for edible fat, kidney, and muscle of chickens is 0.01 mg/kg. However, no maximum residue limit has been established for eggs. In the present study, the pharmacokinetic profile and levamisole residue in the eggs from laying hens were investigated using ultra-performance liquid chromatography-tandem mass spectrometry. A single dose of levamisole (30 mg/kg) was administered via the intramuscular or oral route, and an additional egg residue study was performed with 300 or 600 mg/kg commercial LEV drug (30 or 60 mg/kg as levamisole) orally. The limit of quantification was 0.0056 μg/mL and 0.0015 mg/kg for plasma and eggs, respectively. The plasma concentration was below the limit of quantification 10 and 12 h after intramuscular and oral administration, respectively. The half-life of the absorption phase was comparable between the intramuscular and oral routes, which was approximately 1 h, and the mean maximum concentration value was significantly higher in intramuscular (2.29 ± 0.30 μg/mL) than in oral (1.45 ± 0.38 μg/mL) route. The relative oral bioavailability after intramuscular administration was 92.3%. In the egg residue study, dose-dependent area under concentration and maximum concentration were observed after single oral administration of 30 and 60 mg/kg egg residue, and the calculated withdrawal period for both 30 and 60 mg/kg groups based on the positive list system standard (0.01 mg/kg) was 7 d after the treatment.

Detection of chemical contaminants in heat processed meat products based on UPLC-MS/MS

An ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was established for the simultaneous analysis of acrylamide (AA), 5-hydroxymethylfurfural (HMF), and heterocyclic aromatic amines (HAAs). A good separation of nine analytes was achieved within 15 min. Correlation coefficients (R2 >0.9995) of the nine compounds were obtained within their respective linear ranges. The method also possessed low limits of detection (0.3 ng/mL for IQ, Norharman, 7,8-DiMeIQ, 10.00 ng/mL for MeIQ, 5-HMF, 0.05 ng/mL for PhIP, Phe-P-1, 0.10 ng/mL for Harman, 20.00 ng/mL for AA) and limits of quantification (15.00 mg/kg for IQ, Norharman, 7,8-DiMeIQ, 450.00 mg/kg for MeIQ, 3.00 mg/kg for PhIP, Phe-P-1, 300.00 mg/kg for 5-HMF and 750.00 mg/kg for AA). The method developed for the determination of samples commonly found among Sichuan cuisine, and fast food had good precision (RSD<9%) and recovery (83%-113%). This study provides a basis for the simultaneous rapid determination of nine chemical contaminants commonly found in thermally processed meat products and provides a technical reference for the simultaneous rapid determination of more chemical contaminants in thermally processed meat products.

Metabolomic profiling of amino acids study reveals a distinct diagnostic model for diabetic kidney disease

Diabetic kidney disease (DKD), a highly prevalent complication of diabetes mellitus, is a major cause of mortality in patients. However, identifying circulatory markers to diagnose DKD requires a thorough understanding of the metabolic mechanisms of DKD. In this study, we performed ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) to reveal altered metabolic profiles of amino acids (AAs) in patients with DKD. We found decreased plasma levels of histidine and valine, increased urine levels of proline, decreased urine levels of histidine and valine, and increased saliva levels of arginine in patients with DKD compared with the levels in patients with type 2 diabetes mellitus (T2DM) and in healthy controls. Our analyses of the key metabolites and metabolic enzymes involved in histidine and valine metabolism indicated that the AAs level alterations may be due to enhanced carnosine hydrolysis, decreased degradation of homocarnosine and anserine, enhanced histidine methylation, and systemic enhancement of valine metabolism in patients with DKD. Notably, we generated a distinct diagnostic model with an AUC of 0.957 and an accuracy up to 92.2% on the basis of the AA profiles in plasma, urine and saliva differing in patients with DKD using logistic regression and receiver operating characteristic analyses. In conclusion, our results suggest that altered AA metabolic profiles are associated with the progression of DKD. Our DKD diagnostic model on the basis of AA levels in plasma, urine, and saliva may provide a theoretical basis for innovative strategies to diagnose DKD that may replace cumbersome kidney biopsies.

Isotopic internal standard correction for the determination of diludine residue in animal-derived matrix samples using enhanced matrix removal-lipid clean-up combined with ultra-performance liquid chromatography-tandem mass spectrometry

A robust method has been established for the successfully determination of diludine (DHP) levels in animal-derived matrix samples, utilizing enhanced matrix removal-lipid clean-up (EMR-lipid) combined with ultra-performance liquid chromatography-tandem mass spectrometry (UPLC–MS/MS). DHP-13C4 was employed as an isotopically labeled internal standard to estimate the recovery, matrix effect, and process efficiency. The water-acetonitrile mixture was utilized to extract the edible tissues (muscle, fat, kidney, and liver) of cattle and chicken, while the salting out method was employed for extracting egg and milk. The extracts were then mixed with water and acetonitrile to a constant volume, and subjected to clean-up via cartridge. Subsequently, the analytes were transferred onto a reversed-phase C18 analytical column and quantified by triple-quadrupole tandem mass spectrometry in multiple-reaction monitoring mode. Quantification was accomplished using a solvent calibration curve in conjunction with an internal standard method. The proposed method showed good linearity in the range of 0.5–50 ng mL−1 (R2 ≥ 0.999), high sensitivity (the limit of detection was 2.5 μg kg−1, and the limit of quantification was 5 μg kg−1), a high spiked recovery rate (between 82.6% and 109.4%), and repeatability (the relative deviation within the batch and the relative deviation between batches were ≤ 7.5%).

Inhibitory mechanism of vortioxetine on CYP450 enzymes in human and rat liver microsomes.

Vortioxetine is a novel anti-major depression disorder drug with a high safety profile compared with other similar drugs. However, little research has been done on drug-drug interactions (DDI) about vortioxetine. In this paper, the inhibitory effect of vortioxetine on cytochrome P450 (CYP450) and the type of inhibitory mechanism were investigated in human and rat liver microsomes. We set up an in vitro incubation system of 200μL to measure the metabolism of probe substrates at the present of vortioxetine at 37°C. The concentrations of the metabolites of probe substrates were all measured by ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method. It was found no time-dependent inhibition (TDI) of vortioxetine through determination of half-maximal inhibitory concentration (IC50) shift values. The enzymes and metabolites involved in this experiment in human and rats were as follows: CYP3A4/CYP3A (midazolam); CYP2B6/CYP2B (bupropion); CYP2D6/CYP2D (dextromethorphan); CYP2C8/CYP2C-1 (amodiaquine); CYP2C9/CYP2C-2 (losartan); and CYP2C19/CYP2C-3 (mephenytoin). We found that vortioxetine competitively inhibited CYP2C19 and CYP2D6 in human liver microsomes (HLMs) with inhibition constant (Ki) values of 2.17μM and 9.37μM, respectively. It was noncompetitive inhibition for CYP3A4 and CYP2C8, and its Ki values were 7.26μM and 6.96μM, respectively. For CYP2B6 and CYP2C9, vortioxetine exhibited the mixed inhibition with Ki values were 8.55μM and 4.17μM, respectively. In RLMs, the type of vortioxetine inhibition was uncompetitive for CYP3A and CYP2D (Ki = 4.41 and 100.9μM). The inhibition type was competitive inhibition, including CYP2B and CYP2C-2 (Ki = 2.87 and 0.12μM). The inhibition types of CYP2C-1 and CYP2C-3 (Ki = 39.91 and 4.23μM) were mixed inhibition and noncompetitive inhibition, respectively. The study of the above mechanism will provide guidance for the safe clinical use of vortioxetine so that the occurrence of DDI can be avoided.

Mid-dosing interval concentration is important for polymyxin B exposure and acute kidney injury in critically ill patients.

This study aimed to evaluate the association between polymyxin B (PMB) exposure and acute kidney injury (AKI) and analyze the risk factors for PMB-induced AKI in critically ill patients. Plasma concentrations of PMB were determined using an ultraperformance liquid chromatography-tandem mass spectrometer in intensive care unit patients who were administered PMB. Univariate and multivariate analyses were conducted to identify risk factors. A receiver operating characteristic curve was constructed to assess the discriminant power of the factors and to identify the cutoff value for AKI. The white blood cell count and estimated area under the concentration-time curve (AUC) of patients administered PMB were independent risk factors for PMB-induced AKI, where AUC were calculated using a first-order pharmacokinetic equation based on the mid-dosing interval concentration (C1/2t ) and peak concentration. The area under the receiver operating characteristic curve of the final model was 0.805 (95% confidence interval, 0.690-0.921). The cutoff value for the combined predictor was 0.57. Alternatively, when using C1/2t , which was strongly correlated with AUC, as the only independent risk factor, the analysis showed that the 3.47 μg/ml threshold provides favorable differentiation between the AKI and non-AKI groups. These results provide insightful information for therapeutic drug monitoring-guiding PMB dosing in clinical practice.

Cooking, Digestion, and In Vitro Colonic Fermentation of Nigerian Wholegrains Affect Phenolic Acid Metabolism and Gut Microbiota Composition.

Wholegrains contain both fibre and phenolic acids (PAs), and their gastrointestinal modifications are critical for their bioavailability and bioactivity. We evaluated the modifications on the PA profile and gut microbiota composition of selected Nigerian wholegrains, following cooking and gastrointestinal digestion. Red fonio, red millet, red sorghum, and white corn were cooked, digested, and fermented using an in vitro colonic model. A total of 26 PA derivatives were quantified in soluble and bound fractions using Ultraperformance Liquid Chromatography-Tandem Mass Spectrometry (UPLC-MS/MS) analysis. DNA samples were analysed using 16S rRNA amplicon sequencing to profile the microbiota composition. The results show that cooking and digestion significantly affected the levels of PAs in all grains (p ≤ 0.05) compared to raw grains. Colonic fermentation resulted in a peak of total soluble PAs at 4-6 h for red sorghum and white corn and at 24 h for red millet and red fonio. Enterobacteriaceae genera were the most abundant at 24 h in all grains studied. 3-hydroxybenzaldehyde correlated positively with the relative abundance of Dorea and the mucus-degrader bacteria Akkermansia (p ≤ 0.05), whereas hydroferulic acid and isoferulic acid levels correlated negatively with Oscillospira and Ruminococcus (p ≤ 0.05), respectively. Our data indicate that cooking, digestion, and colonic fermentation affect the release of bound PAs from wholegrains and, consequently, their metabolic conversion. Furthermore, PA fermentation in the gut is associated with potentially relevant changes in the microbiota. This in vitro study provides the basis for the design of an in vivo human intervention study that can confirm the trends herein observed but also assess the impact on health outcomes.