Search Results (571)

Boa constrictor snakes represent a suitable model for studying the absorption, metabolism, and elimination of tramadol due to their distinct physiological characteristics. The objective of this work was to provide preliminary data on the pharmacokinetics of tramadol and its active metabolite, O-desmethyltramadol (M1), in the plasma of Boa constrictor using liquid chromatography with fluorescence detection. Ten snakes received tramadol (5 mg kg⁻¹) both into the epaxial musculature (TRIM) and into the paravertebral vein (TRIV) with a 45-day interval between the two administration methods. Blood samples were taken at specified time points to analyze the pharmacokinetics. Data were evaluated with an independent pharmacokinetic model (R software version 4.3.0). A paired Student’s t-test was used for all parametric variables, except clearance, which was analyzed with the Wilcoxon test. A significance level of 5% was applied. The mean (range) maximum concentration of tramadol, volume of distribution, clearance, and elimination half-life for the TRIM group were 2.58 µg mL⁻¹, 10.58 ± 2.91 L kg⁻¹, 0.36 L kg⁻¹ h⁻¹, and 19.96 ± 8.34 h, respectively. For the TRIV group, these values were 3.39 µg mL⁻¹, 5.60 ± 1.69 L kg⁻¹, 0.22 L kg h⁻¹, and 17.32 ± 7.55 h⁻¹, respectively. M1 achieved maximum concentration and elimination half-lives of 0.58 µg mL⁻¹ and 49.89 ± 10.8 h, respectively, for TRIM and 0.59 µg mL⁻¹ and 35.66 ± 10.85 h for TRIV. The bioavailability of intramuscular tramadol was 61%, and M1 remained at similar concentrations for 20 min after tramadol administration in both treatments. Tramadol is rapidly biotransformed into M1 in Boa constrictors, maintaining high concentrations over an extended period. The pharmacokinetic characteristics, particularly the sustained plasma concentrations of M1, suggest potential for effective analgesia in the Boa constrictor. Furthermore, the intramuscular route provides the additional advantage of ease and practicality of administration. Full article

Background/Objectives: Rest–activity rhythm (RAR) disturbances can contribute to aging and dementia via metabolic dysregulation. Hydroxycholesterol (OH) is thought to mediate the link between hypercholesterolemia and neurodegeneration. This study compared sleep and RAR parameters between amnestic mild cognitive impairment (aMCI) patients and normal controls (NCs), and examined their associations with plasma 27-OH levels, reflecting peripheral cholesterol metabolism. Methods In total, 18 aMCI patients (76.6 ± 6.1 years) and 21 NCs (70.4 ± 6.7 years) underwent five-day actigraphy and dim light melatonin onset assessment. Plasma 27-OH levels were measured via high-performance liquid chromatography-mass spectrometry. Generalized linear models (GLMs) were used to analyze the relationships between sleep, RAR, and 27-OH levels. Results: The aMCI group had significantly lower 27-OH levels and 27-OH/total cholesterol ratios (p < 0.05). GLM revealed that longer sleep onset latency (SOL) was associated with higher 27-OH levels in aMCI, distinguishing them from NCs. Additionally, in aMCI, longer SOL, lower sleep efficiency (SE), and higher fragmentation index (FI) were associated with an increased 27-OH/total cholesterol ratio (p < 0.05). Higher relative amplitude of RAR was linked to lower 27-OH levels across groups (p < 0.01), but RAR parameters showed no significant association with the 27-OH/total cholesterol ratio. Sleep disturbances, including prolonged SOL, reduced SE, and increased FI, were associated with altered peripheral cholesterol oxygenation in aMCI. Conclusions: Greater RAR amplitude correlated with lower 27-OH levels, regardless of cognitive status. These findings suggest that peripheral cholesterol oxygenation in aMCI is related to both sleep disturbances and circadian rhythm dysregulation, highlighting their role in cholesterol metabolism and neurodegeneration. Full article

Plasma-activated water (PAW), enriched with reactive oxygen and nitrogen species (RONS), presents oxidative and antimicrobial characteristics with potential in cosmetic applications. This study examined the effects of two PAW formulations—nitrate-rich (PAW-N) and peroxide-rich (PAW-P)—on human hair types classified as straight (Type 1), wavy (Type 2), and coily/kinky (Type 4). The impact of PAW on hair structure and chemistry was evaluated using Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), UV–Vis spectrophotometry, and physicochemical analyses of the liquids (pH, ORP, conductivity, and TDS). PAW-N, with high nitrate content (~500 mg/L), low pH (2.15), and elevated conductivity (6244 µS/cm), induced significant damage to porous hair types, including disulfide bond cleavage, protein oxidation, and lipid degradation, as indicated by FTIR and EDS data. SEM confirmed severe cuticle disruption. In contrast, PAW-P, containing >25 mg/L of hydrogen peroxide and exhibiting milder acidity and lower ionic strength, caused more localized and controlled oxidation with minimal morphological damage. Straight hair showed greater resistance to both treatments, while coily and wavy hair were more susceptible, particularly to PAW-N. These findings suggest that the formulation and ionic profile of PAW should be matched to hair porosity for safe oxidative treatments, supporting the use of PAW-P as a gentler alternative in hair care technologies. Full article

An oat protein isolate is an ideal raw material for producing a wide range of plant-based products. However, oat protein exhibits weak functional properties, particularly in emulsification. Casein-based ingredients are commonly employed to enhance emulsifying properties as a general practice in the food industry. pH-shifting processing is a straightforward method to partially unfold protein structures. This study modified a mixture of an oat protein isolate (OPI) and casein by combining a pH adjustment (adjusting the pH of two solutions to 12, mixing them at a 3:7 ratio, and maintaining the pH at 12 for 2 h) with an atmospheric cold plasma (ACP) treatment to improve the emulsifying properties. The results demonstrated that the ACP treatment significantly enhanced the solubility of the OPI/casein mixtures, with a maximum solubility of 82.63 ± 0.33%, while the ζ-potential values were approximately −40 mV, indicating that all the samples were fairly stable. The plasma-induced increase in surface hydrophobicity supported greater protein adsorption and redistribution at the oil/water interface. After 3 min of treatment, the interfacial pressure peaked at 8.32 mN/m. Emulsions stabilized with the modified OPI/casein mixtures also exhibited a significant droplet size reduction upon extending the ACP treatment to 3 min, decreasing from 5.364 ± 0.034 μm to 3.075 ± 0.016 μm. The resulting enhanced uniformity in droplet size distribution signified the formation of a robust interfacial film. Moreover, the ACP treatment effectively enhanced the emulsifying activity of the OPI/casein mixtures, reaching (179.65 ± 1.96 m²/g). These findings highlight the potential application value of OPI/casein mixtures in liquid dairy products. In addition, dairy products based on oat protein are more conducive to sustainable development than traditional dairy products. Full article

Regional anesthesia techniques such as the ultrasound-guided PECS II (pectoral nerve block) block are increasingly employed to optimize perioperative analgesia while minimizing systemic anesthetic exposure. Ropivacaine is commonly used for its favorable pharmacological profile; however, clinical data on its pharmacokinetics and systemic metabolite behavior following interpectoral administration remain limited. This study aimed to characterize the plasma concentration–time profile of ropivacaine and its main active metabolite, 3-OH-ropivacaine, in patients undergoing interpectoral nerve block, using a validated LC-MS/MS (liquid chromatography coupled with mass spectrometry) method. Venous blood samples were collected from 18 patients at predefined time points (0, 1, 3, 6, and 24 h) following a PECS II block performed with a ropivacaine-lidocaine mixture. Plasma concentrations were quantified via a validated LC-MS/MS protocol in accordance with FDA (Food and Drug Administration) and EMA (European Medicines Agency) guidelines. Pharmacokinetic parameters were derived using non-compartmental analysis. Ropivacaine reached a mean peak plasma concentration (Cmax—maximum concentration) of 167.5 ± 28.3 ng/mL at 1.3 ± 0.2 h (Tmax—maximum time). The metabolite 3-OH-ropivacaine peaked at 124.1 ± 21.4 ng/mL at 2.3 ± 0.3 h. The terminal elimination half-life was 19.4 ± 2.8 h for ropivacaine and 29.2 ± 3.1 h for its metabolite. Plasma levels demonstrated prolonged systemic exposure with predictable pharmacokinetics. The PECS II block using ropivacaine results in sustained systemic levels of both the parent drug and its primary metabolite, supporting its role in prolonged perioperative analgesia. These data provide a pharmacokinetic foundation for personalized regional anesthesia protocols. This strategy facilitates the adaptation of anesthetic protocols to the individual characteristics of each patient, aligning with the principles of personalized medicine, particularly in patients with altered metabolic capacity. Full article

Background/Objectives: Vitamin D (VD) is metabolized in the body and plays a crucial role in regulating the antioxidant system. While exposure to heavy metals (HMs) inhibits VD activity, HMs can also be absorbed following VD stimulation. Despite differing views on the interaction between HM and VD activity, the effects of HM exposure on VD-related pathways have not been examined using metabolomics. This study aimed to investigate the impact of HM exposure on VD-related antioxidant activity under VD deficiency conditions using untargeted metabolic profiling. Methods: In this retrospective cohort study, 46 plasma samples were analyzed using ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-QTOF/MS). Metabolic profiling was performed on two groups: individuals with severe VD deficiency and low HM exposure (SVDD–LHM) and those with VD deficiency and high HM exposure (VDD–HHM). Results: As a compensatory response to oxidative stress induced by HMs, VD-related antioxidant pathways may be associated with elevated levels of antioxidants, including bilirubin, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). In-creases in EPA and DHA were also linked to alterations in lipid metabolism, including diacylglycerol and phosphatidylcholine levels. DHA showed an area under the curve (AUC) of 0.850 (95% CI: 0.651–0.990), suggesting that DHA could serve as a potential biomarker for VD activity in response to HM exposure. Conclusions: The identified metabolites and metabolic pathways suggest that HM exposure may stimulate VD-related antioxidant activity, even under VD-deficient conditions. Full article

Propolis is a natural resinous substance produced by honeybees that has many biological activities. For thousands of years, it has been widely used as a dietary supplement and traditional medicine to treat a variety of ailments due to its antimicrobial, anti-inflammatory, antioxidant, immunomodulatory, and wound-healing properties. Nutritional supplements and foods may interact with drugs both pharmacodynamically and pharmacokinetically, which could raise clinical concerns. Background/Objectives: This study aimed to investigate the effect of propolis on the plasma disposition of enrofloxacin and to assess the potential pharmacokinetic interaction in rabbits. Methods: In this study, enrofloxacin was applied per os (20 mg/kg) and IM (10 mg/kg) and with propolis (100 mg resin/kg) administration in four groups of rabbits (each of six individuals). Heparinized blood samples were collected at 0, 0.1, 0.3, 0.5, 1, 2, 4, 8, 12, and 24 h post-administration. HPLC-FL was used to analyze the plasma concentrations of enrofloxacin and its active metabolite ciprofloxacin following liquid–liquid phase extraction, i.e., protein precipitation with acetonitrile and partitioning with sodium sulfate. Results: The results revealed that propolis coadministration significantly affected the plasma disposition of enrofloxacin and its active metabolite after both per os and intramuscular administration routes. Significantly greater AUC (48.91 ± 11.53 vs. 26.11 ± 12.44 µg.h/mL), as well as longer T_1/2λz (11.75 ± 3.20 vs. 5.93 ± 2.51 h) and MRT (17.26 ± 4.55 vs. 8.96 ± 3.82 h) values of enrofloxacin and its metabolite ciprofloxacin, were observed after the coadministration of propolis compared to enrofloxacin alone following both per os and IM routes in rabbits. Conclusions: The concurrent use of propolis and prescription medications may prolong the half-life (T_1/2λz) and increase the systemic availability of chronically used drugs with narrow therapeutic indices. The repeated use of drugs such as antibiotics, heart medications, and antidepressants, or drugs with a narrow therapeutic index such as antineoplastic and anticoagulant agents, can cause toxic effects by raising blood plasma levels. Considering the varied metabolism of rabbits and humans, further validation of this study may require thorough clinical trials in humans. Full article

Heterozygous mutations in the GBA1 gene, encoding the enzyme glucocerebrosidase (GCase), are major risk factors for Parkinson’s Disease (PD). Ambroxol, a small chaperone originally used as a mucolytic agent, has been shown to cross the blood–brain barrier, enhance GCase activity, and reduce α-synuclein levels, making it a promising therapeutic candidate for disease-modifying effects in GBA1-associated PD (GBA1-PD). This study aimed to develop a method to quantify ambroxol levels in human plasma and cerebrospinal fluid (CSF) using liquid chromatography–tandem mass spectrometry (LC-MS/MS). Ambroxol was determined by online solid-phase extraction (SPE), coupled with LC-MS/MS, by gradient elution on a monolithic column. Detection employed a 3200 QTRAP tandem mass spectrometer in the positive electrospray ionization mode. Calibration curves exhibited linearity across the analyzed ranges in both plasma and CSF. The recovery rate ranged from 106.7% to 113.5% in plasma and from 99.0% to 103.0% in CSF. No significant matrix effect was observed. Intra-day and inter-day precisions were below 11.8% in both matrices, and accuracy ranged from 89.9% to 103.1% in plasma and from 96.3% to 107.8% in CSF. We evaluated and confirmed the stability of the analyte in plasma and CSF across various storage conditions. The method was successfully validated according to European Medicine Agency (EMA) guidelines and its applicability was confirmed in the context of a multicenter, randomized, double-blind, placebo-controlled, phase II study, designed to monitor the ambroxol levels in the plasma and CSF of GBA1-PD. Full article

Objectives: The anticancer effects of PI3Kα inhibitors (PI3Ki) are constrained by their hyperglycemic side effects, while the efficacy of conventional hypoglycemic agents, such as insulin, metformin, and SGLT-2 inhibitors, in mitigating PI3Ki-induced hyperglycemia remains suboptimal. Dorzagliatin, a novel glucokinase activator, has been approved in China for the management of hyperglycemia, offering a promising alternative. This study aims to investigate the pharmacokinetic properties and potential mechanisms of drug interactions of dorzagliatin in the regulation of PI3K-induced hyperglycemia. Methods: Plasma concentrations of WX390, BYL719, and Dorz in mice were measured using high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. Pharmacokinetic (PK) parameters and PK/PD models were derived by using Phoenix WinNonlin 8.3.5 software. Blood glucose levels at various time points and tumor volume changes over a four-week period were assessed to explore the interactions when PI3Ki were combined with dorzagliatin. Results: The results indicated that, compared to the Dorz group, the combination groups (Dorz + BYL719, Dorz + WX390) exhibited increases in ${\mathrm{A}\mathrm{U}\mathrm{C}}_{0\to t}$ of dorzagliatin by 41.65% and 20.25%, and in C_max by 33.48% and 13.32%, respectively. In contrast, co-administration of these PI3Ki with dorzagliatin resulted in minimal increase in their plasma exposure. The combination therapy group (Dorz+BYL719) exhibited superior antitumor efficacy compared to the BYL719 group. Conclusions: Our findings indicate that the drug–drug interactions (DDIs) between dorzagliatin and multiple PI3Ki (including WX390 and BYL719) may partially account for the enhanced antitumor efficacy observed in the combination therapy group compared to PI3Ki monotherapy. This interaction may be explained by the inhibition of P-glycoprotein (P-gp) and the pharmacological mechanism of dorzagliatin regarding the activation of insulin regulation. Full article

Background/Objectives: Sustained drug exposure is a key factor in the treatment of patients infected with human immunodeficiency virus (HIV) or hepatitis B virus (HBV) in order to achieve the intended virological response. Although influenced also by other parameters, adherence to the treatment scheme is the most important for adequate drug exposure. This can be assessed by therapeutic drug monitoring (TDM). Tenofovir (TFV) is a nucleotide analogue used in the treatment of both HIV and HBV. Although various analytical methods for the quantification of tenofovir prodrugs have been published, there is limited literature on methods for simultaneous TFV and its active metabolite, tenofovir diphosphate (TFVDP) direct determination. Methods: In this study, we describe a novel micro-liquid-chromatography-mass spectrometry (micro-LC-MS/MS) method for TDM of TFV and TFVDP in biological matrices (whole blood, plasma). The challenging separation of the high-polarity analytes was resolved on an amino stationary phase, eluted in HILIC (hydrophilic interaction liquid chromatography) mode. The sample preparation included a clean-up step with hexane for the removal of lipophilic compounds and then protein precipitation with organic solvent. Results: The achieved low limits of quantification in blood were 0.25 ng/mL for TFV, and 0.5 ng/mL for TFVDP. Linearity, accuracy (91.63–109.18%), precision (2.48–14.08), and stability were validated for whole blood matrix, meeting the guidelines performance criteria. Samples collected from treated patients were analyzed, with results being in accordance with the reported pharmacokinetics. Conclusions: The new method is adequate for analyzing samples in a clinical set-up. The measurement of both TFV and TFVDP improves clinical decision by an in-depth evaluation of long-term adherence, and together with viral load and resistance data helps guiding the treatment towards the intended virological suppression. Full article

This study aimed to determine the pharmacokinetic profile of the active dipyrone metabolites, 4-methylaminoantipyrine and 4-aminoantipyrine, following intravenous administration in dogs. Eleven mixed-breed dogs received a 25 mg·kg⁻¹ dipyrone dose and blood samples were collected at 0, 5, 15, 30 and 45 min, as well as at 1, 1.5, 2, 4, 6, 8, 10, 12, 24, 36 and 48 h. Plasma concentrations of both metabolites were analyzed by ultra-performance liquid chromatography coupled to mass spectrometry. The PKSolver 2.0 and GraphPad Prisma 10 software programs were used for pharmacokinetic and statistical analyses, applying a Principal Component Analysis for MAA and descriptive statistics for both metabolites. Two groups were noteworthy concerning MAA: slow metabolizers (SM) and normal/rapid metabolizers (NM). Significant differences were observed between half-life (T_½) and MRT_{0_inf obs} values between the MAA groups. The T_½ and MRT_{0_info obs} were 44.44 ± 11.74 and 32.62 ± 16.53 h for the SM group and 11.25 ± 5.37 and 7.44 ± 4.25 h for the NM group, respectively. The C_max of AA was 2.80 ± 1.43 µg mL⁻¹. Metabolites were detectable for 48 h in all animals for MAA and seven for AA. These findings suggest that metamizole reaches analgesia plasma concentrations associated with cyclooxygenase inhibition with few adverse effects in dogs. However, additional pharmacogenetic and pharmacotherapeutic monitoring studies are required. Full article

Background: Exosomes are nanoscale extracellular vesicles actively secreted by cells that play critical roles in disease biomarker discovery, drug delivery, and direct therapeutic applications. However, in vivo pharmacokinetic (PK) studies of exosomes remain limited, hindering their clinical translation. Due to their complex and heterogeneous composition, most existing PK methods rely on chemical or genetic labeling, which may alter their native behavior and complicate accurate analysis. Methods: To address this challenge, we developed a label-free liquid chromatography–tandem mass spectrometry (LC-MS/MS) method to investigate the PK of naive exosome-based therapeutic modalities. Exosomes were isolated from rat plasma using size exclusion chromatography (SEC) and quantified using multiple reaction monitoring (MRM) targeting specific exosomal peptides as surrogate analytes. Following intravenous administration of exosomes via the tail vein, plasma concentrations were determined by peptide peak areas, and PK parameters were calculated using a non-compartmental model. Results: The method was rigorously validated for specificity, linearity, sensitivity, and reproducibility. Its feasibility was further confirmed by successfully characterizing the PK profile of HEK 293F-derived exosomes in rats. Conclusions: This analytical strategy enables direct, label-free quantification of exosomes in plasma and provides a robust platform for advancing exosome-based drug development and translational research. Full article

Background: Chronic atrophic gastritis precancerous lesions (PL-CAG) are characterized by the atrophy of gastric mucosal glands, often accompanied by intestinal metaplasia or dysplasia. Timely intervention and treatment can effectively reverse its malignant progression and prevent the onset of gastric cancer. Bombyx Batryticatus (BB) exhibits a range of pharmacological effects, including anticoagulation, antiepileptic properties, anticancer activity, and antibacterial effects. However, the pharmacological basis and mechanisms underlying BB’s efficacy in treating PL-CAG remain unclear. Methods: A three-factor modeling approach was implemented to develop a rat PL-CAG model, while the MNNG-induced PLGC (precancerous lesions of gastric cancer) cell model was served as a cell PL-CAG model. UPLC-QE-Orbitrap-MS/MS (Ultra performance liquid chromatography-quadrupole-electrostatic field orbital trap high-resolution mass spectrometry) was utilized to perform an in-depth analysis of the components in the plasma extract of BB. Leveraging network pharmacology, molecular docking analyses, and experimental validation, we initially elucidated the potential mechanisms through which BB mediates its therapeutic effects on PL-CAG at both in vivo and in vitro levels. Results: Prototype compounds of 42 blood-entering components were identified by UPLC-QE-Orbitrap-MS/MS analysis. Network pharmacology analysis and molecular docking studies indicate that the core targets are primarily enriched in the PI3K-Akt signaling pathway, and the key components, including Nepitrin, Quercetin 3-O-neohesperidoside, Rutin, and others, exhibited stable docking conformations with the first eleven pivotal targets. Both in vivo and in vitro experiments validated that BB may effectively treat PL-CAG via modulation of the PI3K-Akt signaling pathway. Conclusions: The therapeutic efficacy of BB in the management of PL-CAG may be achieved through the synergistic interaction of multiple components and targets, which may be more closely related to the inhibition of the PI3K/AKT signaling pathway. This approach will establish a solid experimental foundation and provide essential data for the clinical application of BB in treating PL-CAG, while also facilitating further research initiatives. Full article

Cystic fibrosis (CF) is a life-threatening disorder caused by mutations in the CFTR gene, leading to defective chloride ion transport and thickened mucus in the respiratory and gastrointestinal systems. CFTR modulators, including ivacaftor, lumacaftor, tezacaftor, and elexacaftor, have improved patient outcomes, but interindividual pharmacokinetic variability and potential drug–drug interactions require therapeutic drug monitoring (TDM) for optimal efficacy and safety. In this context, a liquid chromatography–tandem mass spectrometry (LC-MS/MS) method has been developed and validated for the simultaneous quantification of CFTR modulators and their major active metabolites in human plasma to support pharmacokinetic studies and routine TDM. The multiplex LC-MS/MS assay was established using plasma protein precipitation, followed by chromatographic separation on an Xselect HSS T3 (Waters^®) column and positive electrospray ionization mode detection. The method was validated based on FDA and EMA guidelines for specificity, linearity, accuracy (89.8–107.8%), repeatability (1.1–8.1%), intermediate fidelity (1.3–10.9%), matrix effects, and stability, demonstrating a robust performance with excellent precision and accuracy. International interlaboratory comparisons confirmed the reliability of the assay. The developed method can be applied for the clinical monitoring of caftors’ plasma concentrations and preliminary data suggest that it can also be applied to alternative matrices, such as breast milk. This method will serve to characterize caftors’ pharmacokinetic variability and monitor drug–drug interactions to further refine personalized dosing strategies and enhance precision medicine treatments for patients with CF. Full article

In this study, we established a mutagenesis and high-throughput screening system to select a high-yielding glutathione (GSH)-producing strain of Saccharomyces cerevisiae. The parent strain was mutated by atmospheric and room temperature plasma (ARTP) technology and cultivated using ethionine plate cultivation. Subsequently, high-throughput screening was performed using liquid deep microtiter plates (MTPs) for cultivation and a microplate reader for rapid GSH detection. The results demonstrated the successful selection of a stable mutant strain, S-272, which exhibited significantly enhanced GSH production. Fermentation validation in 5 L bioreactors revealed that S-272 achieved a 14.7% higher final GSH concentration and a 19.5% higher intracellular GSH content compared to the parent strain. The improved performance of S-272 was attributed to enhanced ethanol utilization, elevated activity of γ-glutamylcysteine synthetase (γ-GCS), and increased intracellular trehalose content. This study presents an effective strategy for developing high GSH-yield strains using ARTP complex mutagenesis technology combined with high-throughput screening. Full article