Plasma Concentrations Research Articles

Impact of UGT1A4 and UGT2B7 polymorphisms on lamotrigine plasma concentration in patients with bipolar disorder.

The purpose of this study was to evaluate the effect of UGT1A4 and UGT2B7 polymorphisms on the plasma concentration of lamotrigine in Chinese patients with bipolar disorder. A total of 104 patients were included in this study. Steady-state plasma lamotrigine concentrations were determined in each patient after at least 21 days of continuous treatment with a set dose of the drug. Lamotrigine plasma concentrations were ascertained using ultra-performance liquid chromatography. Simultaneously, plasma samples were used for patient genotyping. The age, sex, BMI, daily lamotrigine dose, plasma lamotrigine concentration, and lamotrigine concentration/dose ratio of patients exhibited significant differences, and these were associated with differences in the genotype [ UGT1A4 -142T>G and UGT2B7 -161C>T ( P < 0.05)]. Patients with the GG and GT genotypes in UGT1A4 -142T>G had significantly higher lamotrigine concentration/dose values (1.6 ± 1.1 and 1.7 ± 0.5 μg/ml per mg/kg) than those with the TT genotype (1.4 ± 1.1 μg/ml per mg/kg). Likewise, patients with the UGT2B7 -161C>T TT genotype had significantly higher lamotrigine concentration/dose values (1.6 ± 1.1 μg/ml per mg/kg) than those with the CC genotype (1.3 ± 1.3 μg/ml per mg/kg). Multiple linear regression analysis showed that sex, lamotrigine dose, UGT1A4 -142T>G, and UGT2B7 -161C>T were the most important factors influencing lamotrigine pharmacokinetics ( P < 0.001). The study results suggest that the UGT1A4 -142T>G and UGT2B7 -161C>T polymorphisms affect lamotrigine plasma concentrations in patients with bipolar disorder.

Renal Function and Its Impact on the Concentration of Ceftazidime-Avibactam: A cross-sectional study

ObjectivesThis study measured the effect of renal function on the plasma concentrations of ceftazidime and avibactam in critically ill patients. We also sought to measure the concentration ratio of ceftazidime to avibactam. MethodsThis was a cohort study at a tertiary referral centre in Italy, on patients treated with continuous infusion of ceftazidime-avibactam (CAZ-AVI) between November 2019 and December 2023. The association between creatine clearance (CrCl) and free plasma ceftazidime and avibactam concentration, as well as CAZ-AVI ratio was explored to assess correlation and potential risk to fail to achieve target therapeutic concentration. Results52 patients, predominantly male (75%), with a median age of 68.5 years were included. Our analyses provided strong evidence for inverse correlation between CrCl and both free-CAZ (r=-0.627; R2=0.3936; P<0.001) and free-AVI plasma concentration (r=-0.619; R2=0.3832; P<0.001). Overall CrCl alone could explain about 40% of overall variation of either free-CAZ and free-AVI. Linear models suggest that free-CAZ and free-AVI concentration drop of about 7.31% and 9.23% for each 10 point increase of CrCl, respectively. . Assessment of the CAZ-AVI ratio supports a direct linear association with CrCl suggesting that free-AVI concetration is more affected by CrCl variation than free-CAZ concentration. Patients with CrCl ≥130 mL/min showed a significantly higher risk of suboptimal drug exposure (i.e. less than 4 times the MIC) both to CAZ and AVI. ConclusionThe findings emphasize the need for individualized dosing strategies of CAZ-AVI based on renal function, for antibiotics used in critically ill patients. The study suggests that underdosing in patients with high CrCl is likely to be common and as such could affect drug effectiveness.

Development, validation and application of a high-performance liquid chromatography method for the detection of ibuprofen in elephant plasma

A simple and accurate method for the determination of ibuprofen concentrations in elephant plasma was developed and validated using reverse phase high-performance liquid chromatography (HPLC). Utilizing a liquid-liquid extraction with ethyl acetate, methanol, and phosphoric acid, samples were separated on an XBridge C18 column. The mobile phase consisted of 0.005 M ammonium phosphate and acetonitrile (40:60, v/v). Both ibuprofen and the internal standard flurbiprofen were quantitated using an ultraviolet (UV) detector set at 214 nm. The lower limit of quantification (LLOQ) was 0.05 μg/mL in 100 μL of plasma. The average recovery was over 95% while the intra-assay variability ranged from 0.8 to 9.9% and the inter-assay variability ranged from 2.7 to 9.8%. The method was used successfully in a therapeutic drug monitoring program for elephants and could be used in future pharmacokinetic studies.

SULF1 expression is increased and promotes fibrosis through the TGF-β1/SMAD pathway in idiopathic pulmonary fibrosis

BackgroundIdiopathic pulmonary fibrosis (IPF) is a chronic and progressive interstitial lung disease of unknown etiology. Despite the increasing global incidence and poor prognosis, the exact pathogenic mechanisms remain elusive. Currently, effective therapeutic targets and treatment methods for this disease are still lacking. This study tried to explore the pathogenic mechanisms of IPF. We found elevated expression of SULF1 in lung tissues of IPF patients compared to normal control lung tissues. SULF1 is an enzyme that modifies heparan sulfate chains of heparan sulfate proteoglycans, playing a critical role in biological regulation. However, the effect of SULF1 in pulmonary fibrosis remains incompletely understood. Our study aimed to investigate the impact and mechanisms of SULF1 in fibrosis.MethodsWe collected lung specimens from IPF patients for transcriptome sequencing. Validation of SULF1 expression in IPF patients was performed using Western blotting and RT-qPCR on lung tissues. ELISA experiments were employed to detect SULF1 concentrations in IPF patient plasma and TGF-β1 levels in cell culture supernatants. We used lentiviral delivery of SULF1 shRNA to knock down SULF1 in HFL1 cells, evaluating its effects on fibroblast secretion, activation, proliferation, migration, and invasion capabilities. Furthermore, we employed Co-Immunoprecipitation (Co-IP) to investigate the regulatory mechanisms involved.ResultsThrough bioinformatic analysis of IPF transcriptomic sequencing data (HTIPF) and datasets GSE24206, and GSE53845, we identified SULF1 may potentially play a crucial role in IPF. Subsequently, we verified that SULF1 was upregulated in IPF and predominantly increased in fibroblasts. Furthermore, SULF1 expression was induced in HFL1 cells following exposure to TGF-β1. Knockdown of SULF1 suppressed fibroblast secretion, activation, proliferation, migration, and invasion under both TGF-β1-driven and non-TGF-β1-driven conditions. We found that SULF1 catalyzes the release of TGF-β1 bound to TGFβRIII, thereby activating the TGF-β1/SMAD pathway to promote fibrosis. Additionally, TGF-β1 induces SULF1 expression through the TGF-β1/SMAD pathway, suggesting a potential positive feedback loop between SULF1 and the TGF-β1/SMAD pathway.ConclusionsOur findings reveal that SULF1 promotes fibrosis through the TGF-β1/SMAD pathway in pulmonary fibrosis. Targeting SULF1 may offer a promising therapeutic strategy against IPF.

The Pharmacokinetic Interaction of Tirabrutinib with Voriconazole, Itraconazole, and Fluconazole in SD Rats by UPLC-MS/MS.

Tirabrutinib is an orally effective, approved, and highly selective second-generation Bruton's tyrosine kinase (BTK) inhibitor for the treatment of recurrent or refractory primary central nervous system lymphoma (PCNSL). This study aimed to develop an ultra-high performance liquid chromatography- tandem mass spectrometry (UPLC-MS/MS) method for the determination of tirabrutinib concentration in rat plasma, where zanubrutinib was used as an internal standard (IS). This method was also applied to study whether tirabrutinib would interact with voriconazole, itraconazole, and fluconazole in rats, providing a reference value for clinical medication guidance. In the current study, the organic solvent protein precipitation method was used to treat plasma samples, which is simple and reproducible. Tirabrutinib (m/z 455.32 → 320.21) and zanubrutinib (m/z 472.13 → 455.04) were separated on a Waters Acquity BEH C18 column (2.1 × 50 mm, 1.7 μm) and detected by multiple reaction monitoring (MRM) in positive ionization mode. The method showed good linearity in the range of 5-3000 ng/mL for tirabrutinib with the lower limit of quantification (LLOQ) of 5 ng/mL. The recovery and matrix effects were 85.7-91.0% and 102.0-113.3%, respectively. The accuracy, precision, stability, and carry-over effect were also acceptable. The method could also be used for determining the pharmacokinetic interaction of tirabrutinib in rats. The results showed AUC0→∞ of tirabrutinib to be increased by 139.3% and 83.9% in the presence of voriconazole and fluconazole, respectively, while itraconazole had little effect. It is necessary to monitor the concentration of tirabrutinib in patients when it is combined with voriconazole and fluconazole to achieve a better therapeutic effect and reduce the risk of adverse reaction. Further research should be conducted in the future.

Pharmacokinetics, pharmacodynamics, and safety of izuforant, an H4R inhibitor, in healthy subjects: A phase I single and multiple ascending dose study.

Izuforant is a selective, and potent histamine H4 receptor (H4R) antagonist developed to treat atopic dermatitis (AD). There is an unmet medical need for therapeutic agents to control inflammation and pruritus. Izuforant is a strong candidate for this task based on the findings of non-clinical studies showing that inhibition of the histamine-mediated signaling pathway via H4R by izuforant results in decreased pruritus and inflammation. This study aimed to evaluate the clinical pharmacokinetic (PK) and pharmacodynamic (PD) profiles of izuforant. Dose-block-randomized, double-blind, placebo-controlled, single- and multiple ascending dose studies were conducted in 64 healthy volunteers. For the single ascending dose (SAD) study, 10-600 mg izuforant was administered to the designated groups. For the multiple ascending dose (MAD) study, 100-400 mg izuforant was administered to three groups. The clinical pharmacokinetic (PK) profile of izuforant was evaluated using plasma and urine concentrations. Blood sampling for the PD assay, which measured imetit-induced eosinophil shape changes (ESC), was also conducted. A one-compartment PK model described the distribution and elimination profiles of izuforant. An imetit-induced ESC inhibition test was established and validated for PD evaluation as a measure of the H4R antagonistic effect. ESC inhibition was observed even at doses as low as 10 mg; however, this inhibition became stronger and lasted longer as the dose increased. All izuforant doses were well tolerated, and no discontinuations due to adverse events (AE) or deaths were reported.

Dietary protein intake and the tubular handling of indoxyl sulfate.

Chronic kidney disease (CKD) patients are advised to limit their protein intake. A high protein diet is known to induce glomerular hyperfiltration, as well as hypertrophy of the remnant kidney, and glomerulosclerosis. Whether the diet causes changes in kidney tubule transport via gut microbiome metabolites is still unknown. We hypothesized that protein intake affects not only the intestinal generation and absorption, but also the kidney disposal of microbial amino acid metabolites. We combined data from animal models and human studies. 5/6th nephrectomy rats were administered a high (HP) or low-protein (LP) diet for 7 weeks. Plasma and urine concentration of the uremic toxins (UTs) indoxyl sulfate (IS), p-cresyl sulfate (PCS), and p-cresyl glucuronide (PCG) were measured. Their fractional excretion (FE) was calculated. The expression of kidney membrane transporters OAT1, OAT3, BCRP, OCT2 and MRP4 was analyzed. Differences in FE of UTs between individuals with higher and lower protein intake in two CKD cohorts were sought. CKD rats on an HP diet showed increased plasma levels of PCS and PCG but not IS compared to rats on a LP diet. Conversely, urinary excretion and FE of IS were higher in the HP CKD group. BCRP, MRP4 and OCT2 were not influenced by the diet. OAT1 and OAT3 were upregulated in the HP CKD group. In two independent cohorts of CKD patients, individuals with a high dietary protein intake showed a significantly higher FE of IS. A HP diet leads to a higher generation and/or absorption of aminoacid-derived UT precursors in CKD rodent models and humans, most likely via gut microbiome modulation. We demonstrate that dietary protein intake modulates transcription and expression of OAT1 and OAT3, corroborating the existence of the remote sensing and signaling hypothesis. Dietary protein intake influences kidney physiology beyond glomerular filtration.

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 (s- GC), 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.

On the relationship between hERG inhibition and the magnitude of QTc prolongation: An in vitro to clinical translational analysis

Assessing the magnitude of QTc prolongation is crucial in drug development due to its association with Torsades de Pointes. Inhibition of the hERG channel, pivotal in cardiac repolarization, is a key factor in evaluating this risk. In this study, the relationship between hERG inhibition and QTc prolongation magnitude was investigated, with the aim to derive simple guidance on the required hERG margin to avoid a large (>20 ms) QTc prolongation. MethodsData from literature and FDA sources were searched for compounds with hERG IC50 values alongside clinical QTc data with paired plasma concentrations, or compounds demonstrating a clinical concentration-QTc relationship. Relationships between hERG inhibition, hERG IC50 margin to unbound plasma Cmax, and QTc prolongation magnitude were calculated. ResultsAnalysis of 148 clinical QTc observations from 98 compounds revealed that compounds associated with QTc prolongation >10 ms typically exhibited hERG margins of ≤33-fold, while those exceeding 20 ms were generally associated with margins of ≤24-fold. QTc increases above 10 ms were not observed at hERG margins >100-fold. Based on 53 clinical concentration-QTc datasets, modest hERG inhibition levels of ~4–6 % correlated with a 10 ms QTc prolongation, while ~10–13 % inhibition corresponded to a 20 ms prolongation. ConclusionsThis study enhances understanding of the relationship between hERG inhibition and QTc prolongation magnitude, by conducting analysis across a wide range of 98 compounds. This information can be used to determine the optimal hERG margin, particularly for drug discovery projects with limited scope to completely design-out hERG activity.

Dysregulated nicotinamide adenine dinucleotide metabolome in patients hospitalized with COVID-19.

Nicotinamide adenine dinucleotide (NAD+) depletion has been postulated as a contributor to the severity of COVID-19; however, no study has prospectively characterized NAD+ and its metabolites in relation to disease severity in patients with COVID-19. We measured NAD+ and its metabolites in 56 hospitalized patients with COVID-19 and in two control groups without COVID-19: (1) 31 age- and sex-matched adults with comorbidities, and (2) 30 adults without comorbidities. Blood NAD+ concentrations in COVID-19 group were only slightly lower than in the control groups (p < 0.05); however, plasma 1-methylnicotinamide concentrations were significantly higher in patients with COVID-19 (439.7 ng/mL, 95% CI: 234.0, 645.4 ng/mL) than in age- and sex-matched controls (44.5 ng/mL, 95% CI: 15.6, 73.4) and in healthy controls (18.1 ng/mL, 95% CI 15.4, 20.8; p < 0.001 for each comparison). Plasma nicotinamide concentrations were also higher in COVID-19 group and in controls with comorbidities than in healthy control group. Plasma concentrations of 2-methyl-2-pyridone-5-carboxamide (2-PY), but not NAD+, were significantly associated with increased risk of death (HR = 3.65; 95% CI 1.09, 12.2; p = 0.036) and escalation in level of care (HR = 2.90, 95% CI 1.01, 8.38, p = 0.049). RNAseq and RTqPCR analyses of PBMC mRNA found upregulation of multiple genes involved in NAD+ synthesis as well as degradation, and dysregulation of NAD+-dependent processes including immune response, DNA repair, metabolism, apoptosis/autophagy, redox reactions, and mitochondrial function. Blood NAD+ concentrations are modestly reduced in COVID-19; however, NAD+ turnover is substantially increased with upregulation of genes involved in both NAD+ biosynthesis and degradation, supporting the rationale for NAD+ augmentation to attenuate disease severity.

Cardiorespiratory effects of Gamma-Hydroxybutyric Acid (GHB) during isoflurane anaesthesia in pigs

ObjectiveTo investigate the haemodynamic effects of gamma-hydroxybutyric acid (GHB) in isoflurane anaesthetised pigs. Study DesignExperimental, randomized, non-blinded, cross-over study. AnimalsA group of six stress-resistant Landrace pigs (approximately 3 months old; three male, three female; bodyweight 39.2 ± 4 kg (mean ± standard deviation). MethodsAfter premedication (midazolam 0.5 mg kg-1 and ketamine 10 mg kg-1 intramuscularly), and induction [propofol 0.25–0.5 mg kg-1 intravenously IV)], anaesthesia was maintained with isoflurane in oxygen, and either GHB 250 mg kg-1 IV or an equal volume of saline was administered (minimum washout period 1 week). Systolic (SAP), diastolic (DAP), and mean (MAP) arterial pressures, heart rate and rhythm, respiratory rate, were recorded every 5 minutes for 2 hours. Arterial samples were collected for blood gas and pharmacokinetic analyses. Relative changes from baseline were calculated and compared between treatments using a mixed model with time, period, and treatment as variables (α < 0.05). ResultsChanges from baseline differed significantly between treatments (p < 0.001) for SAP (GHB -1.6 ± 10.7; saline -5.9 ± 14.8 mmHg), DAP (GHB +2.9 ± 9.6; saline -6.5 ± 10.7 mmHg) and MAP (GHB +2.2 ± 10.5; saline -5.7 ± 9.6 mmHg). Statistical analysis of secondary outcomes suggested effects on PaO2 (GHB -45.2 ± 29.8 mmHg [-6.03 ± 3.97 kPa]; saline +24.5 ± 32.4 mmHg [+3.27 ± 4.32 kPa]; p < 0.001) and PaCO2 (GHB -2 ± 10 mmHg [-0.27 ± 1.33 kPa]; saline -9 ± 8 mmHg [-1.20 ± 1.07 kPa]; p < 0.001). Mean maximum plasma concentration of GHB was 1171.1 ± 229.3 μg mL-1, with volume of distribution 335.3 ± 68.5 mL kg-1, clearance 77.2 ± 19.12 mL kg-1 hour-1 and elimination half-life 3.10 ± 0.80 hours. Conclusions and clinical relevanceGHB did not cause severe physiological side effects and may reduce cardiovascular depression.

Dosing of Venetoclax in Pediatric Patients with Relapsed Acute Myeloid Leukemia: Analysis of Developmental Pharmacokinetics and Exposure-Response Relationships

This work aimed to characterize the pharmacokinetics and exposure-response relationships of venetoclax in pediatric patients with relapsed or refractory (R/R) acute myeloid leukemia (AML) to identify venetoclax doses to be administered to pediatric patients in the phase 3 study. Data from 121 patients across three phase 1 studies enrolling pediatric patients with R/R malignancies were utilized to develop a population pharmacokinetic model to describe venetoclax pharmacokinetics in pediatric patients. Individual patient average venetoclax plasma concentration up to the event of interest, derived based on the population pharmacokinetics analysis, was used to evaluate the exposure-response relationships to efficacy (complete response) and safety (neutropenia and thrombocytopenia) endpoints for patients with AML who received venetoclax in combination with azacitidine, decitabine, or cytarabine (n = 36). The population pharmacokinetic model was then used to simulate exposures in pediatric age- and weight-based subgroups to identify the venetoclax doses for pediatric patients. The pharmacokinetic data were adequately described by the two-compartment population pharmacokinetic model with first-order absorption and elimination. The model accounted for cytochrome P450 3A developmental changes using a maturation function and incorporated allometric scaling to account for growth and body size effect. Weight was identified as a statistically significant covariate on clearance and volume of distribution and retained in the final model. Population pharmacokinetic estimates were comparable to previously reported estimates in adults. Exposure-response analyses suggested that the clinical efficacy of venetoclax in combination with high-dose cytarabine (HDAC) is maximized at 600 mg adult-equivalent, and higher doses are unlikely to enhance clinical efficacy. Venetoclax 600 mg adult-equivalent was selected for further development in combination with HDAC. Additionally, venetoclax 400 mg adult-equivalent was selected for bridging/maintenance therapy in combination with azacitidine. Flat exposure-response relationships were observed with Grade ≥3 neutropenia and thrombocytopenia. Doses were selected based on weight (allometric scaling) for children aged ≥2 years old and based on weight and CYP3A ontogeny for children aged <2 years. The selected age- and weight-based dosing scheme of venetoclax is projected to achieve venetoclax exposures in pediatric subgroups comparable to those observed in adults receiving venetoclax 400 mg or 600 mg. This work characterized the pharmacokinetics and exposure-response relationships of venetoclax in pediatric patients and guided the selection of pediatric dosing regimens in support of the venetoclax phase 3 trial in pediatric AML (NCT05183035). NCT03236857, NCT03181126, and NCT03194932.

Interactions of the Osteokines, Glucose/Insulin System and Vascular Risk Networks in Patients With Newly Diagnosed Type 2 Diabetes (VNDS 15).

Bone as an endocrine organ regulates metabolic processes independently of mineral metabolism through the production/release of proteins collectively named 'osteokines'. Relevant connections were reported between the insulin/glucose system, calcification of the atherosclerotic plaque, and several osteokines. We aimed to test the hypothesis that the osteokine network could be involved in beta-cell function, insulin sensitivity, and vascular damage in a cohort of people with newly diagnosed type 2 diabetes (T2D). In 794 drug-naive, GADA-negative, newly-diagnosed T2D patients (mean±SD age: 59±9.8years; BMI: 29.3±5.3kg/m2; HbA1c: 6.6±1.3%) we assessed: plasma concentration of osteocalcin (OCN), osteopontin (OPN),RANKL, and its putative decoy receptor osteoprotegerin (OPG); insulin sensitivity (SI) by hyperinsulinemic euglycemic clamp; beta cell function (BCF), estimated by OGTT minimal modelling and expressed as derivative (DC) and proportional (PC) control. Echo-doppler of carotid and lower limb arteries were also performed in 708 and 701 subjects, respectively. OCN, RANKL and OPG were significantly associated with PC (p<0.02); OCN was positively related to DC (p=0.018). OPG was associated with lower IS (p<0.001). Finally, the higher RANKL levels, the greater was the severity of atherosclerosis in common carotid artery (p<0.001). Increased OPG and OPN concentrations were related to subclinical atherosclerosis in peripheral arteries of lower limbs (p=0.023 and p=0.047, respectively). These data suggest that, in patients with newly diagnosed T2D, the osteokine network crosstalks with the glucose/insulin system and may play a role in modulating the atherosclerotic process.

Absorption, Anti-inflammatory, Antioxidant, and Cardioprotective Impacts of a Novel Fasting Mimetic Containing Spermidine, Nicotinamide, Palmitoylethanolamide, and Oleoylethanolamide: A Pilot Dose-Escalation Study in Healthy Young Adult Men

This pilot dose-escalation study evaluated the absorption and metabolism of a novel fasting mimetic formulation containing spermidine, nicotinamide, palmitoylethanolamide (PEA), and oleoylethanolamide (OEA) taken as oral supplements in young adults. Five healthy men consumed a standardized breakfast, followed by control (wheat flour) or low, medium, or high doses of supplements containing spermidine, nicotinamide, PEA, and OEA 2 h later. Blood was drawn at 0, 1, 2, and 4 h after the supplement (2, 3, 4, and 6 h postprandial). Plasma concentrations of spermidine, 1-methylnicotinamide (1-MNA), PEA and OEA were quantified by LC-MS. The secretion of tumor necrosis factor alpha (TNF-α) and production of reactive oxygen species (ROS) by stimulated macrophages incubated with plasma, and cholesterol efflux capacity (CEC) of plasma were analyzed. Plasma 1-MNA, PEA and OEA concentrations increased after supplement intake (P < 0.05). Spermidine concentrations decreased in the control arm (P < 0.05) but not the supplement arms. Net incremental area under the curve for TNF-α and ROS in stimulated macrophages decreased when incubated with plasma following supplement intake (P < 0.05). Intake of the combined supplements showed they were bioavailable and increased in plasma in a dose-dependent manner, and provide preliminary data showing enhanced plasma anti-inflammatory and antioxidant functions.This trial was registered at clinicaltrials.gov (NCT05017428).

Transcription and post-translational mechanisms: dual regulation of adiponectin-mediated Occludin expression in diabetes

BackgroundOccludin, a crucial component of tight junctions, has emerged as a promising biomarker for the diagnosis of acute ischemic disease, highlighting its significant potential in clinical applications. In the diabetes, Occludin serves as a downstream target gene intricately regulated by the adiponectin (APN) signaling pathway. However, the specific mechanism by which adiponectin regulates Occludin expression remains unclear.Methods and resultsEndothelial-specific Ocln knockdown reduced APN-mediated blood flow recovery after femoral artery ligation and nullified APN's protection against high-fat diet (HFD)-triggered apoptosis and angiogenesis inhibition in vivo. Mechanically, we have meticulously elucidated APN's regulatory role in Occludin expression through a comprehensive analysis spanning transcriptional and post-translational dimensions. Foxo1 has been elucidated as a crucial transcriptional regulator of Occludin that is modulated by the APN/APPL1 signaling axis, as evidenced by validation through ChIP-qPCR assays and Western blot analysis. APN hindered Occludin degradation via the ubiquitin–proteasome pathway. Mass spectrometry analysis has recently uncovered a novel phosphorylation site, Tyr467, on Occludin. This site responds to APN, playing a crucial role in inhibiting Occludin ubiquitination by APN. The anti-apoptotic and pro-angiogenic effects of APN were attenuated in vitro and in vivo following Foxo1 knockdown or expression of a non-phosphorylatable mutant, OccludinY467A. Clinically, elevated plasma concentrations of Occludin were observed in patients with diabetes. A significant negative correlation was found between Occludin levels and APN concentrations.ConclusionOur study proposes that APN modulates Occludin expression through mechanisms involving both transcriptional and post-translational interactions, thereby conferring a protective effect on endothelial integrity within diabetic vasculature.Graphical abstract

Understanding the mechanisms of food effect on omaveloxolone pharmacokinetics through physiologically based biopharmaceutics modeling.

Omaveloxolone is a nuclear factor (erythroid-derived 2)-like 2 activator approved in the United States and the European Union for the treatment of patients with Friedreich ataxia aged ≥16 years, with a recommended dosage of 150 mg orally once daily on an empty stomach. The effect of the US Food and Drug Administration (FDA) high-fat breakfast on the pharmacokinetic profile of omaveloxolone observed in study 408-C-1703 (NCT03664453) deviated from the usual linear correlation between fed/fasted maximum plasma concentration (Cmax) and area under the concentration-time curve (AUC) ratios reported for various oral drugs across 323 food effect studies. Here, physiologically based biopharmaceutics modeling (PBBM) was implemented to predict and explain the effect of the FDA high-fat breakfast on a 150-mg dose of omaveloxolone. The model was developed and validated based on dissolution and pharmacokinetic data available across dose-ranging, food effect, and drug-drug interaction clinical studies. PBBM predictions support clinical observations of the unique effect of a high-fat meal on omaveloxolone pharmacokinetic profile, in which the Cmax increased by 350% with only a 15% increase in the AUC. Key parameters influencing omaveloxolone pharmacokinetics in the fasted state based on a parameter sensitivity analysis included bile salt solubilization, CYP3A4 activity, drug substance particle size distribution, and permeability. Mechanistically, invivo omaveloxolone absorption was solubility and dissolution rate limited. However, in the fed state, higher bile salt solubilization led to more rapid dissolution with predominant absorption in the upper gastrointestinal tract, resulting in increased susceptibility to first-pass gut extraction; this accounts for the lack of correlation between Cmax and AUC for omaveloxolone.

Elucidation of DPP-4 involvement in systemic distribution and renal reabsorption of linagliptin by PBPK modeling with a cluster Gauss-Newton method.

The dipeptidyl peptidase-4 (DPP-4) inhibitor linagliptin (LNG) exhibits target-mediated drug disposition (TMDD) in clinical settings, characterized by saturable binding to plasma soluble DPP-4 (sDPP-4) and tissue transmembrane DPP-4 (tDPP-4). Previous studies have indicated that saturable renal reabsorption of LNG contributes to its nonlinear urinary excretion observed in humans and wild-type mice, but not in Dpp-4 knockout mice. To elucidate the mechanisms underlying these complex phenomena, including DPP-4-related renal reabsorption of LNG, we employed physiologically-based pharmacokinetic (PBPK) modeling combined with a cluster Gauss-Newton method (CGNM). The CGNM facilitated the exploration of parameters in rat and human PBPK models for LNG and the determination of parameter identifiability. Through PBPK-CGNM analysis using reported autoradiography data ([14C]-LNG) in wild-type and Dpp-4-deficient rats, DPP-4-specific distributions of LNG in various tissues were clearly differentiated from nonspecific parts. By fitting to human plasma concentrations and urinary and fecal excretions of LNG after intravenous and oral administrations, multiple unknown PBPK parameters were simultaneously estimated by the CGNM. Notably, the amount of tDPP-4 and the reabsorption clearance for LNG-DPP-4 complexes were identifiable, indicating their critical role in explaining the complex nonlinear pharmacokinetics of LNG. Compared with previous PBPK analyses, the CGNM allowed us to incorporate greater model complexity (e.g., consideration of tDPP-4 expressions and invitro binding kinetics), ultimately resulting in a more accurate reproduction of LNG's TMDD. In conclusion, by considering LNG as a high-affinity probe for DPP-4, comprehensive PBPK-CGNM analyses suggested a dynamic whole-body distribution of DPP-4, including its involvement in the renal reabsorption of LNG.

Absolute oral bioavailability of milvexian spray-dried dispersion formulation under fasted and fed conditions in healthy adult participants: An intravenous microtracer approach.

Milvexian is an oral, small-molecule factor XIa inhibitor being developed to prevent thromboembolic events. This study assessed the absolute bioavailability (F) of milvexian following single doses of milvexian spray-dried dispersion (SDD) formulation under fed and fasted conditions, and milvexian solution, in healthy adult participants using an intravenous microtracer approach. This was a phase I, open-label, partially randomized, 4-sequence, 5-period crossover study. After fasting for ≥10 h, participants received milvexian 200-mg oral solution with a 100-μg 14C milvexian intravenous microtracer at the time of maximum observed plasma concentration. Following a 3-day washout, participants were randomized to 1 of 4 milvexian SDD treatment sequences in a crossover fashion: 25 mg fasted, 25 mg fed, 200 mg fasted, or 200 mg fed. Pharmacokinetic data were collected up to 72 h postdose. Seventeen participants were dosed, and 14 completed treatment. Under fasted conditions, milvexian F was ~100%, 58.2%, and 54.2% following administration of the oral solution, 25 mg SDD, and 200 mg SDD, respectively. Under fed conditions, milvexian F following 25 mg and 200 mg SDD was 44.3% and 75.6%, respectively. The milvexian SDD formulation at 25 mg and 200 mg resulted in similar F in a fasted state; under fed conditions, milvexian F decreased at 25 mg and increased at 200 mg. These findings clarify pharmacokinetic-related gaps observed in previous studies.

Low thiamine status in adults following low-carbohydrate / ketogenic diets: a cross-sectional comparative study of micronutrient intake and status.

Low-carbohydrate diets (LCD) are popular for weight loss but lack evidence about micronutrient sufficiency in real-life use. This study assessed the intake and biochemical status of selected micronutrients in people voluntarily following LCDs. A cross-sectional study was conducted (2018-20) among 98 adults recruited as self-reporting either LCD (n = 49) or diets not restricting carbohydrates (controls; n = 49). Diets were assessed using the 130-item EPIC-Norfolk food-frequency questionnaire. Red-blood-cell thiamine diphosphate (TDP) was measured for thiamine status using HPLC. Plasma magnesium, zinc, copper, and selenium were measured using inductively coupled plasma mass spectrometry. Between-group biomarker comparisons were conducted using ANCOVA and adjusted for age, sex, body mass index (BMI), and diabetes status. LCD-followers (26% male, median age 36 years, median BMI 24.2 kg/m2) reported adhering to LCDs for a median duration of 9 months (IQR 4-36). The most followed LCD type was 'their own variations of LCD' (30%), followed by ketogenic (23%), 'palaeolithic' (15%), and Atkins diets (8%). Among controls, 41% were male (median age 27 years, median BMI 23kg/m2). Median macronutrient intakes for LCD vs control groups were carbohydrate 16%Energy (E) vs. 50%E; protein 25%E vs. 19%E; and fat 55%E vs 34%E (saturated fat 18%E vs. 11%E). Two-thirds of LCD followers (32/49) and half of the controls (24/49) reported some use of dietary supplements (p = 0.19). Among LCD-followers, assessing from food data only, 21 (43%) failed to meet the reference nutrient intake (RNI) for thiamine (vs.14% controls, p = 0.002). When thiamine from supplementation (single- or multivitamin) was included, there appeared to be no difference in thiamine intake between groups. Still, red-blood-cell TDP was lower in LCD-followers than controls (407 ± 91 vs. 633 ± 234 ng/gHb, p < 0.001). Three LCD-followers were thiamine-deficient (RBC thiamine < 275 ng/gHb) vs. one control. There were no significant differences in dietary intakes or plasma concentrations of magnesium, zinc, copper, and selenium between groups. Following LCDs is associated with lower thiamine intake and TDP status than diets without carbohydrate restriction, incompletely corrected by supplement use. These data, coupled with a lack of RCT evidence on body weight control, do not support recommending LCDs for weight management without appropriate guidance and diet supplementation.

Comparative intrafollicular and plasma iron, ferritin, and transferrin concentrations in cycling mares

Background and Aim: In females of various species and experimental animals, iron (Fe) status in follicular fluid (FF) is associated with local physiological reproductive events related to follicle development, steroidogenesis, and oocyte maturation. However, these mechanisms remain unknown. This study aimed to determine and compare the intrafollicular and plasma concentrations of Fe, ferritin (Ferr), and transferrin (TRF) in cycling mares. Materials and Methods: Sixty ovaries were collected during the breeding season from 30 clinically normal mares raised for slaughterhouse meat production. Blood samples were collected before slaughter. Follicles were classified into three categories according to size: Small (20–30 mm; n = 20), medium (≥31–40 mm; n = 20), and large (≥41 mm; n = 20). The FF samples, after collection, were immediately taken to the laboratory for processing and were centrifuged, and the Fe and Ferr concentrations in the supernatant and plasma were determined by spectrophotometry. Results: Although intrafollicular Fe and Ferr were similar to plasma, TRF was significantly higher in FF than in systemic circulation (p &lt; 0.05). Follicular development does not modify the status of Fe in the mare. Conclusion: Based on this evidence, it is possible that the acquisition of this molecule possibly originated from a local de novo source, whereas their diffusion through ultrafiltration does not play a relevant role. These results provide new scientific insights into the status of follicle Fe, suggesting its involvement in normal ovarian functions in mares. Keywords: ferritin, follicular fluid, iron, mare, transferrin.