Pharmacokinetic Analysis of Levodropropizine and Its Potential Therapeutic Advantages Considering Eosinophil Levels and Clinical Indications

Levodropropizine is a non-narcotic, non-centrally acting antitussive that inhibits the cough reflex triggered by neuropeptides. Despite the active clinical application of levodropropizine, the exploration of its inter-individual pharmacokinetic diversity and of factors that can interpret it is lacking. The purpose of this study was to explore effective covariates associated with variation in the pharmacokinetics of levodropropizine within the population and to perform an interpretation of covariate correlations from a therapeutic perspective. The results of a levodropropizine clinical trial conducted on 40 healthy Korean men were used in this pharmacokinetic analysis, and the calculated pharmacokinetic and physiochemical parameters were screened for effective correlations between factors through heatmap and linear regression analysis. Along with basic compartmental modeling, a correlation analysis was performed between the model-estimated parameter values and the discovered effective candidate covariates for levodropropizine, and the degree of toxicity and safety during the clinical trial of levodropropizine was quantitatively monitored, targeting the hepatotoxicity screening panel. As a result, eosinophil level and body surface area (BSA) were explored as significant (p-value < 0.05) physiochemical parameters associated with the pharmacokinetic diversity of levodropropizine. Specifically, it was confirmed that as eosinophil level and BSA increased, levodropropizine plasma exposure increased and decreased, respectively. Interestingly, changes in an individual's plasma exposure to levodropropizine depending on eosinophil levels could be interpreted as a therapeutic advantage based on pharmacokinetic benefits linked to the clinical indications for levodropropizine. This study presents effective candidate covariates that can explain the inter-individual pharmacokinetic variability of levodropropizine and provides a useful perspective on the first-line choice of levodropropizine in the treatment of inflammatory respiratory diseases.

Modeling population pharmacokinetics of morniflumate in healthy Korean men: extending pharmacometrics analysis to niflumic acid, its major active metabolite

This study aimed to quantify and explain inter-subject variability in morniflumate pharmacokinetics and identify effective covariates through population pharmacokinetics modeling. Models were constructed using bioequivalence pharmacokinetics results from healthy Korean males and individual physiological and biochemical parameters. Additionally, we incorporated previously reported pharmacokinetics results of niflumic acid, a major active metabolite of morniflumate, to extend the established population pharmacokinetics model and predict niflumic acid pharmacokinetics. Moreover, we used quantitative reports of leukotriene B4 (LTB4) synthesis inhibition in response to niflumic acid exposure to predict drug efficacy using Sigmoid Emax model. Population pharmacokinetics profiles of morniflumate were described using a multi-absorption (5-sequential) two-compartment model, and analysis of inter-individual variability suggested that volume of distribution in peripheral compartment was correlated with body mass index (BMI). Model simulation results showed that individuals with lower BMI had higher plasma concentrations of morniflumate and niflumic acid, resulting in increased and sustained inhibition of LTB4 synthesis. Under steady-state conditions, average plasma concentrations of morniflumate and niflumic acid were 2.66-2.68 times higher in group with a BMI of 17.36 kg/m2 compared to the group with a BMI of 28.41 kg/m2. Additionally, inhibition of LTB4 synthesis was 1.02 times higher in group with a BMI of 17.36 kg/m2 compared to group with a BMI of 28.41 kg/m2, and the fluctuation was significantly reduced from 6.06 to 0.01%. These findings suggest that the concentration of active metabolite in plasma following morniflumate exposure was lower in the obese group compared to the normal group, thus potentially reducing the drug's efficacy.

Sex differences in 4-tert-octylphenol toxicokinetics: Exploration of sex as an effective covariate through an in vivo modeling approach

4-tert-octylphenol (4-tert-OP) is a potentially harmful substance, which is found widely in the environment. Nevertheless, information on the in vivo toxicokinetics of 4-tert-OP is lacking, and quantitative risk assessment studies are urgently needed. Therefore, we aimed to quantitatively identify differences in the toxicokinetics of 4-tert-OP and its distribution among tissues between sexes. To this end, following exposure of male and female rats to 10 or 50 mg/kg 4-tert-OP orally and 4 or 8 mg/kg 4-tert-OP intravenously, we conducted a quantitative analysis of samples using ultra-high performance liquid chromatography-tandem mass spectrometry. The results revealed that the 4-tert-OP plasma concentration profiles differed between sexes; however, systemic absorption of 4-tert-OP through the gastrointestinal tract occurred within 0.5 h of exposure in both sexes. Although small, the excretion percentage of 4-tert-OP in urine and feces was lower in males than females (0.06-0.08% vs. 0.82-1.11% of exposure). Significant sex differences were also confirmed in the tissue distribution patterns of 4-tert-OP, and overall, the average tissue distribution in males was lower than that in females. The distribution of 4-tert-OP to liver, adipose, spleen, kidney, brain, and lung in both sexes was predominant. A covariate exploration modeling approach revealed that sex explained the differences in 4-tert-OP toxicokinetics between sexes. These significant differences in the toxicokinetics and tissue distribution of 4-tert-OP between sexes will be important for the scientific precision human risk assessment of 4-tert-OP.

Is Gender an Important Factor in the Precision Medicine Approach to Levocetirizine?

Currently, there is insufficient information on the variability in levocetirizine pharmacometrics among individuals, a crucial aspect for establishing its clinical use. The gender differences in pharmacokinetics and the extent of variation in pharmacodynamics have not been definitively identified. The primary goal of this study was to investigate gender differences in levocetirizine pharmacokinetics and quantitatively predict and compare how these gender-related pharmacokinetic differences impact pharmacodynamics, using population pharmacokinetic-pharmacodynamic modeling. Bioequivalence results for levocetirizine (only from the control formulation) were obtained from both healthy Korean men and women. Physiological and biochemical parameters for each individual were utilized as pharmacokinetic comparison and modeling data between genders. Pharmacodynamic modeling was performed using reported data on antihistamine responses following levocetirizine exposure. Gender, weight, body surface area, peripheral distribution volume, albumin, central-peripheral inter-compartmental clearance, and the fifth sequential absorption rate constant were explored as effective covariates. A comparison of the model simulation results showed a higher maximum concentration and faster plasma loss in females than in males, resulting in a faster recovery to baseline of the antihistamine effect; however, the absolute differences between genders in the mean values were not large within 10 ng/mL (for plasma concentrations) or % (wheal and flare size changes). Regarding the pharmacokinetics and pharmacodynamics of levocetirizine, the gender effect may not be significant when applying the usual dosage (5 mg/day). This study will be useful for bridging the knowledge gap in scientific precision medicine by introducing previously unconfirmed information regarding gender differences in levocetirizine pharmacometrics.

Review of MR spectroscopy analysis and artificial intelligence applications for the detection of cerebral inflammation and neurotoxicity in Alzheimer's disease

INTRODUCTION

Magnetic resonance spectroscopy (MRS) has an emerging role as a neuroimaging tool for the detection of biomarkers of Alzheimer's disease (AD). To date, MRS has been established as one of the diagnostic tools for various diseases such as breast cancer and fatty liver, as well as brain tumours. However, its utility in neurodegenerative diseases is still in the experimental stages. The potential role of the modality has not been fully explored, as there is diverse information regarding the aberrations in the brain metabolites caused by normal ageing versus neurodegenerative disorders.

MATERIALS AND METHODS

A literature search was carried out to gather eligible studies from the following widely sourced electronic databases such as Scopus, PubMed and Google Scholar using the combination of the following keywords: AD, MRS, brain metabolites, deep learning (DL), machine learning (ML) and artificial intelligence (AI); having the aim of taking the readers through the advancements in the usage of MRS analysis and related AI applications for the detection of AD.

RESULTS

We elaborate on the MRS data acquisition, processing, analysis, and interpretation techniques. Recommendation is made for MRS parameters that can obtain the best quality spectrum for fingerprinting the brain metabolomics composition in AD. Furthermore, we summarise ML and DL techniques that have been utilised to estimate the uncertainty in the machine-predicted metabolite content, as well as streamline the process of displaying results of metabolites derangement that occurs as part of ageing.

CONCLUSION

MRS has a role as a non-invasive tool for the detection of brain metabolite biomarkers that indicate brain metabolic health, which can be integral in the management of AD.

Population pharmacokinetic modeling of levodropropizine: extended application to comparative analysis between commercial formulations and exploration of pharmacokinetic effects of diet

Levodropropizine, a nonopioid antitussive agent, is being increasingly used in clinical practice with the development of several formulations for symptomatic relief of acute and chronic bronchitis. However, scientific and quantitative population pharmacokinetic analyses of levodropropizine are lacking. Moreover, no integrated quantitative comparison has been performed between formulations. This study quantitatively evaluated and predicted pharmacokinetic properties of formulations through population pharmacokinetic model-based comparisons of commercially available formulations. Plasma concentration profile results from bioequivalence studies of 60-mg immediate release (IR) levodropropizine tablets in 40 healthy Korean males were used as population pharmacokinetic modeling data. For interindividual variability in levodropropizine pharmacokinetics, body surface area was identified as an effective covariate that was positively correlated with peripheral compartment distribution volume. Population pharmacokinetic model for IR tablets well-described the levodropropizine syrup and capsule datasets, suggesting no significant differences in pharmacokinetics among IR tablets, syrups, and capsules of levodropropizine. In contrast, pharmacokinetic profiles differed between 90-mg controlled release (CR) and IR levodropropizine tablets; however, separate parameter estimation was possible by applying the same model structure. In terms of pharmacokinetics, twice-daily regimen of 90-mg CR tablets was equivalent to thrice-daily regimen of 60-mg IR tablets. However, at steady-state, interindividual plasma concentration variability within population was reduced by approximately 36.71-83.18%. For levodropropizine CR tablets, a high-fat diet significantly delayed gastrointestinal absorption but maintained overall plasma exposure equivalent. This study provides useful quantitative judgment data for precision medicine of levodropropizine and can be helpful in predicting the pharmacokinetics of levodropropizine based on commercialized formulation switching.

Exploring Differences in Pharmacometrics of Rabeprazole between Genders via Population Pharmacokinetic-Pharmacodynamic Modeling

Rabeprazole is a proton pump inhibitor that inhibits gastric acid production and increases gastric pH; it is widely used clinically as a treatment option for gastritis and gastric ulcers. However, information on the inter-individual variability of rabeprazole pharmacometrics, which is a key element in establishing its scientific clinical use, is still lacking. Particularly, the differences in pharmacokinetics between genders and the degree of variation in pharmacodynamics have not been clearly identified. Thus, the main purpose of this study was to explore any differences in rabeprazole pharmacokinetics between genders and to quantitatively predict and compare the effects of any differences in pharmacokinetics between genders on known pharmacodynamics using population pharmacokinetic-pharmacodynamic modeling. To compare pharmacokinetics and modeling data between genders, bioequivalence results were used simultaneously on healthy Korean men and women using the physiological and biochemical parameters derived from each individual. Pharmacodynamic modeling was performed based on the data of previously reported gastric pH changes in response to rabeprazole plasma concentrations, which was co-linked to the central compartmental bioavailable concentration in the population pharmacokinetic model. There was no significant difference in the level of rabeprazole exposure and elimination of plasma between genders following oral administration of 10 mg enteric-coated rabeprazole tablets; however, there was a clear delay in absorption in women compared to men. Additionally, a comparison of pharmacokinetic parameters normalized to body weight between genders showed that the maximum plasma concentrations were significantly higher in women than in men, again suggesting gender differences in rabeprazole absorption. The population pharmacokinetic profiles for rabeprazole were described using a three-sequential multi-absorption with lag time (Tlag) two-compartment model, whereas body surface area and gender were explored as effective covariates for absorption rate constant and Tlag, respectively. The effect of increased gastric pH due to plasma exposure to rabeprazole was explained using the Sigmoid Emax model, with the baseline as a direct response. The significantly longer rabeprazole Tlag in females delayed the onset of an effect by an average of 1.58 times (2.02-3.20 h), yet the overall and maximum effects did not cause a significant difference within 15%. In the relative comparison of the overall efficacy of rabeprazole enteric-coated tablet administration between genders, it was predicted based on the model that males would have higher efficacy. This study will be very useful in broadening the perspective of interpreting drug diversity between individuals and narrowing the gap in knowledge related to scientific precision medicine by presenting new information on gender differences in rabeprazole pharmacometrics that had not been previously identified.

Inter-individual exposure variability interpretation through reflection of biological age algorithm in physiologically based toxicokinetic model: Application to human risk assessment of di-isobutyl-phthalate

Age-related changes and interindividual variability in the degree of exposure to hazardous substances in the environment are pertinent factors to be considered in human risk assessment. Existing risk assessments remain in a one-size-fits-all approach, often without due consideration of inter-individual toxicokinetic variability factors, such as age. The purpose of this study was to advance from the existing risk assessment of hazardous substances based on toxicokinetics to a precise human risk assessment by additionally considering the effects of physiologic and metabolic fluctuations and interindividual variability in age. Qualitative age-associated physiologic and metabolic changes in humans, obtained through a meta-analysis, were quantitatively modeled to produce the final biological age algorithm (BAA). The developed BAAs (for males) were extended and applied to the reported testicular reproductive toxicity-focused di-isobutyl-phthalate (DiBP)-mono-isobutyl-phthalate (MiBP) physiologically based toxicokinetic (PBTK) model in males. The advanced PBTK model combined with the BAA was applied to the human risk assessment based on MiBP biomonitoring data. As a result, the specialized DiBP external exposure values for each age could be estimated. Additionally, by applying the Monte Carlo simulation, the distribution of internal exposure diversity among individuals according to the same external exposure dose could be estimated. The contributions of physiologic and metabolic factors to the age-dependent toxicokinetic changes were approximately 93.41-99.99 and 0.01-6.59%, respectively. In addition, the relative contribution of metabolic factors was major in infants and continued to decrease as age increased (up to about age 30 years). This study provides a step-by-step platform that can be widely applied to overcome the limitations of existing toxicokinetic models that still require interindividual pharmacokinetic variability explanations. This will be important for the rationalization and explanation of inter-individual variability in the pharmacokinetics of many substances.

P-glycoprotein mechanical functional analysis using in silico molecular modeling: Pharmacokinetic variability according to ABCB1 c.2677G > T/A genetic polymorphisms

P-glycoprotein (P-gp) is a widely membrane-expressed multi-drug transporter. It is unclear whether the pharmacokinetic diversity of P-gp substrates is highly dependent on ABCB1 polymorphisms encoding P-gp. The purpose of this study is to analyze the mechanistic function of P-gp through in silico molecular modeling and to approach the resolution of controversy over pharmacokinetic differences according to ABCB1 polymorphisms. P-gp conformations of apo, ligand-docked, and outward-facing states can be modeled based on structural information of human P-gp. And polymorphic P-gp structures were constructed through homology modeling. ABCB1 c.2677G > T/A (Ala893Ser/Thr), did not correspond to P-gp's nucleotide-binding-domain (NBD) or drug-binding-pocket (DBP) or involve mechanical conformational changes. Although amino acid substitution by ABCB1 c.2677G > T/A caused a 30 % increased strain in an α-helix hinge between the NBD and DBP in P-gp's internal tunnel, there were no overall structural changes compared to wild-type. ABCB1 c.2677G > T/A may increase torsional energy, impacting conformational change rate, but this does not significantly affect P-gp's general functioning. Fexofenadine docking into P-gp's DBP explained the substrate interaction, but no effect by ABCB1 c.2677G > T/A was confirmed. Our findings provide additional insights useful in resolving the debate about the influence of ABCB1 polymorphisms on the interindividual pharmacokinetic variability of P-gp substrates.

Dosage exploration of meloxicam according to CYP2C9 genetic polymorphisms based on a population pharmacokinetic-pharmacodynamic model

BACKGROUND

Meloxicam, used for treating inflammatory diseases, shows large differences in metabolism according to CYP2C9 genetic polymorphisms; however, there are few studies on dose regimen setting based on quantitative predictions.

OBJECTIVE

The aim of this study was to determine the appropriate meloxicam dose regimen for each genotype through population pharmacokinetic-pharmacodynamic modeling of meloxicam by considering CYP2C9 genetic polymorphisms.

METHODS

For modeling, previously reported pharmacokinetic (plasma concentration)-pharmacodynamic (inhibition of thromboxane B₂ generation) data of meloxicam were collected for CYP2C9 genetic polymorphisms (n = 43). And these data were mainly used in the modeling process. Through simulations of the established models, steady-state pharmacokinetic-pharmacodynamic profiles were obtained according to meloxicam multiple exposures for each CYP2C9 genotype, and predictions were made based on dose regimen changes.

RESULTS

Genetic polymorphisms of CYP2C9 were identified as key covariates that significantly affected pharmacokinetic variability of meloxicam between individuals. The developed meloxicam population pharmacokinetic-pharmacodynamic model predicted pharmacokinetic results of the 7.5 mg meloxicam administration groups (n = 26) for CYP2C9*1/*1 and *1/*3 as an external validation. The results of model simulation revealed that the differences were 2.39-5.42 times for steady-state mean plasma concentrations and 1.21-1.71 times for the degree of inhibition of thromboxane B₂ generation following multiple exposures for CYP2C9*1/*1 versus *1/*13, *1/*3, and *3/*3. This suggested that thromboxane B₂ inhibition following increased plasma exposure to meloxicam differed significantly according to CYP2C9 genetic polymorphisms. The dose of meloxicam in CYP2C9*1/*13, *1/*3, and *3/*3 was randomly adjusted to 1.6-15 mg to approximate the mean thromboxane B₂ inhibition for CYP2C9*1/*1 at steady state, the dose intervals varied from 24 h to 48 h.

CONCLUSIONS

The results suggested that clinical dose adjustment of meloxicam would be necessary to account for CYP2C9 genetic polymorphisms and reduce side effects. This study suggests a clearer direction for setting up clinical therapy based on personalized medicine and quantitative predictions for meloxicam.

Population Pharmacokinetic Modeling of Zaltoprofen in Healthy Adults: Exploring the Dosage Regimen

Zaltoprofen is a drug used for various pain and inflammatory diseases. Scientific and quantitative dosage regimen studies regarding its clinical application are scarce. This study aimed to discover effective covariates related to interindividual pharmacokinetic variability through population pharmacokinetic modeling for zaltoprofen and to explore dosage regimens. The bioequivalence results of healthy Korean males, biochemical analysis, and CYP2C9 genotyping information were utilized in modeling. The established model has been sufficiently verified through a bootstrap, goodness-of-fit, visual predictive check, and normalized prediction distribution error. External data sets derived from the literature were used for further model validation. The final model could be used to verify the dosage regimen through multiple exposure simulations according to the numerical change of the selected covariates. Zaltoprofen pharmacokinetics could be explained by a two-compartment with a first-order absorption model. Creatinine clearance (CrCL) and albumin were identified as effective covariates related to interindividual zaltoprofen pharmacokinetic variability, and they had positive and negative correlations with clearance (CL/F), respectively. The differences in pharmacokinetics between individuals according to CYP2C9 genetic polymorphisms (*1/*1 and *1/*3) were not significant or valid covariates. The model simulation confirmed that zaltoprofen pharmacokinetics could significantly differ as the CrCL and albumin levels changed within the normal range. Steady-state plasma exposure to zaltoprofen was significantly reduced in the group with CrCL and albumin levels of 130 mL/min and 3.5 g/dL, respectively, suggesting that dose adjustment may be necessary. This study is useful to guide precision medicine of zaltoprofen and provides scientific quantitative judgment data for its clinical applications.

Physiologically Based Pharmacokinetic (PBPK) Modeling of Lornoxicam: Exploration of doses for CYP2C9 Genotypes and Patients with Cirrhosis

Lornoxicam physiologically based pharmacokinetic (PBPK) models were developed and validated on the basis of clinical pharmacokinetic results obtained by considering CYP2C9 genetic polymorphisms in healthy adult populations. PBPK models were extended to predict lornoxicam pharmacokinetics for patients with cirrhosis by quantitatively examining the pathophysiological information associated with cirrhosis. The predicted plasma exposure to lornoxicam was approximately 1.12-2.83 times higher in the CYP2C9*1/*3 and *1/*13 groups than in the CYP2C9*1/*1 group of healthy adult populations and patients with cirrhosis. The predicted plasma exposure to lornoxicam was approximately 1.28-3.61 times higher in patients with cirrhosis than in healthy adult populations. If the relationship between lornoxicam exposure in plasma and drug efficacy was proportional, then the proposed adjusted doses of lornoxicam for each group varied from 1.25 mg to 8 mg. As the severity of cirrhosis increased, or when the CYP2C9 genotype was *1 heterozygous, the dose adjustment range of lornoxicam increased. Therefore, the effect of pathophysiological factors (cirrhosis severity) on the pharmacokinetics of lornoxicam might be more important than that of CYP2C9 genetic factors. These results could be useful for broadening the scope of clinical application of lornoxicam by enabling dose selection based on CYP2C9 genotypes and liver cirrhosis degree.

Development of physiologically-based toxicokinetic-toxicodynamic (PBTK-TD) model for 4-nonylphenol (4-NP) reflecting physiological changes according to age in males: Application as a new risk assessment tool with a focus on toxicodynamics

Environmental exposure to 4-nonylphenol (4-NP) is extensive, and studies related to human risk assessment must continue. Especially, prediction of toxicodynamics (TDs) related to reproductive toxicity in males is very important in risk-level assessment and management of 4-NP. This study aimed to develop a physiologically-based-toxicokinetic-toxicodynamic (PBTK-TD) model that added a TD prostate model to the previously reported 4-n-nonylphenol (4-n-NP) physiologically-based-pharmacokinetic (PBPK) model. Modeling was performed under the assumption of similar TKs between 4-n-NP and 4-NP because TK experiments on 4-NP, a random-mixture, are practically difficult. This study was very important to quantitatively predict the TKs and TDs of 4-NP by age at exposure using an advanced PBTK-TD model that reflected physiological-changes according to age. TD-modeling was performed based on the reported toxic effects of 4-NP on RWPE-1 cells, a human-prostate-epithelial-cell-line. Through a meta-analysis of reported human physiological data, body weight, tissue volume, and blood flow rate patterns according to age were mathematically modeled. These relationships were reflected in the PBTK-TD model for 4-NP so that the 4-NP TK and TD changes according to age and their differences could be confirmed. Differences in TK and TD parameters of 4-NP at various ages were not large, within 3.61-fold. Point-of-departure (POD) and reference-doses for each age estimated using the model varied as 426.37-795.24 and 42.64-79.52 μg/kg/day, but the differences (in POD or reference doses between ages) were not large, at less than 1.87-times. The PBTK-TD model simulation predicted that even a 100-fold 4-NP POD_man dose would not have large toxicity to the prostate. With a focus on TDs, the predicted maximum possible exposure of 4-NP was as high as 6.06-23.60 mg/kg/day. Several toxicity-related values estimated by the dose-response curve were higher than those calculated, depending upon the PK or TK, which would be useful as a new exposure limit for prostate toxicity of 4-NP.

Impact of right atrial enlargement on clinical outcome in patients with atrial fibrillation

Background

Left atrial (LA) remodeling is associated with adverse cardiovascular events, including heart failure (HF) and stroke in patients with atrial fibrillation (AF). However, there are limited data on the value of right atrial (RA) remodeling in this population. We investigated the prognostic role of RA enlargement in patients with non-valvular AF.

Methods and results

We analyzed 254 consecutive patients (age = 69 ± 12years, male:female = 165:89, mean left ventricular ejection fraction = 58.0 ± 7.2%) with non-valvular AF who underwent two-dimensional echocardiography from a single center. RA and LA volumes were measured from apical views and indexed to the body surface areas (right atrial volume index [RAVI] and left atrial volume index [LAVI]) and RAVI &gt; 30mL/m2 and LAVI &gt; 34mL/m2 were considered as enlarged. The relationship between RA enlargement and composite clinical outcome of hospitalization for HF (HHF), stroke, systemic embolism, or death from any cause was assessed. Right atrial (RA) enlargement was associated with older age and more frequent prevalence of persistent or permanent AF. During a median follow-up of 47.1 months, 77 patients (30%) had experienced primary composite outcome. In a multivariable model, RA enlargement, but not LA enlargement, was independently associated with adverse clinical outcomes even after adjusting for clinical and echocardiographic factors {adjusted hazard ratio [HR], 1.90 [95% confidence interval (CI), 1.14–3.18], p = 0.014 for primary composite outcome; adjusted HR, 2.70 [95% CI, 1.27–5.67], p = 0.001 for HHF or all cause death}.

Conclusion

RA enlargement was independently associated with an increased risk of HF, stroke, systemic embolization or death in patients with non-valvular AF, suggesting that RA volume can be helpful in assessing future cardiovascular risk in this population.

CD26-inhibition correlates with the absence of chronic lung allograft dysfunction and decreases fibroblast activity in vitro

Objective

Chronic lung allograft dysfunction (CLAD) limits the survival after lung transplantation (Tx). CLAD is characterized by progressive fibrosis of small airways and lung parenchyma. No effective therapy is available that reverses or prevents CLAD. CD26 is a molecule with enzymatic activity also playing a key role in the progression of fibrotic diseases. Here, we analyzed the inhibitory effect of CD26 on fibroblast activity in vitro and the role of CD26-inhibition on allograft rejection in lung transplant patients.

Methods

Profibrogenic mRNA and protein levels were analyzed in vitro on the CD26-expressing fibroblast cell line Wi-38 using RT-qPCR and Western blot. CD26 was inhibited by Vildagliptin. Migration and proliferation activity of activated fibroblasts were analyzed by Incucyte® and Celltiter-Glo®. Characteristics of patients undergoing lung Tx between 2004 and 2021 were reviewed. Lung biopsies were analyzed by immunohistochemistry (IHC) for CD26.

Results

In vitro, the expression of profibrogenic genes (αSMA, FAPα, IGFBP7, Collagen 3 and Fibronectin) was significantly reduced in activated lung fibroblasts by Vildagliptin treatment. Also, migration and proliferation activity were attenuated by Vildagliptin. In 221 patients analyzed, CLAD was absent in 34 patients treated with the CD26-inhibitor Sitagliptin vs. an incidence of 18% in patients without Sitagliptin intake (p=0.02). Five-year survival in patients on Sitagliptin was significantly improved vs. patients without CD26-inhibitor intake (80% vs. 58%, p=0.006). Likewise, the incidence of acute cellular rejection (ACR) was significantly reduced in patients on Sitagliptin (7% vs. 35%, p=0.01). IHC of patient lung biopsies showed expression of CD26 in perifibrotic areas of CLAD lesions. Additional clinical data from University Hospital Zurich and from University Hospital Padua confirmed the finding that Sitagliptin intake correlated with the absence of acute and chronic allograft rejection.

Conclusion

CD26-inhibition attenuates key pro-fibrotic mediators and fibroblast activity in vitro. Impressively, patients on CD26-inhibitor did not show any CLAD. Moreover, ACR was significantly reduced. Gliptins which are in routine clinical use for the treatment of type II diabetes therefore seem to have great potential to be repurposed for a novel clinical application against lung allograft rejection.

The effect of Epstein-Barr virus viremia on the progression to severe COVID-19

Epstein-Barr virus (EBV) is frequently reactivated by coronavirus 2019 (COVID-19), and a high incidence of EBV viremia has been reported in patients with severe COVID-19. However, the impact of EBV viremia on progression to severe COVID-19 is unclear. Therefore, we conducted a study to evaluate the effect of EBV on COVID-19 progression.We investigated EBV viremia at the time of admission in COVID-19 patients hospitalized between February 1, 2020, and April 11, 2021. A cross-sectional study was performed to compare the severity of COVID-19 according to the presence or absence of EBV viremia. However, since it is difficult to analyze the influence of EBV viremia on COVID-19 progression with cross-sectional studies, a retrospective cohort study, limited to patients with mild COVID-19, was additionally conducted to observe progression to severe COVID-19 according to the presence or absence of EBV viremia.Two hundred sixty-nine COVID-19 patients were tested for EBV viremia. In a cross-sectional study that included patients with both mild and severe COVID-19, the EBV viremia group had more severe pneumonia than the EBV-negative group. However, in the cohort study limited to mild cases (N = 213), EBV viremia was not associated with COVID-19 progression.COVID-19 severity may affect EBV viremia; however, there was no evidence that EBV viremia was a factor in exacerbating pneumonia in patients with mild COVID-19.

Population Pharmacokinetic (Pop-PK) Analysis of Torsemide in Healthy Korean Males Considering CYP2C9 and OATP1B1 Genetic Polymorphisms

Torsemide is a diuretic drug used for several cardiovascular and chronic diseases. With regard to the clinical application of torsemide, studies on individualized pharmacotherapy and modeling that take variability in pharmacokinetics (PKs) within a population into account have been rarely reported. Thus, the objective of this study was to perform population pharmacokinetic (Pop-PK) modeling and to identify effective covariates that could explain the inter-individual variability (IIV) of torsemide PK. Pop-PK modeling for torsemide was performed based on serum concentration data obtained from 112 healthy Korean males and analysis of various genetic and physicochemical parameters. Modeling was performed with nonlinear mixed-effects (NLME) using Phoenix NLME. The finally developed model was fully verified. The model was also reconfirmed using NONMEM software. As a basic model, the PKs of torsemide within the population were well described by a two-compartment model reflecting the lag-time on oral absorption. According to the genetic polymorphisms of OATP1B1 and CYP2C9, significant associations were found in the V/F, CL/F, and CL₂/F of torsemide. These were reflected as effective covariates in the final Pop-PK model of torsemide, resulting in an approximately 5–10% improvement in the model parameter IIV values. Considering that torsemide is a substrate for CYP2C9 and OATP1B1, it was important to search for genetic polymorphisms in CYP2C9 and OATP1B1 as covariates to explain the PK diversity of torsemide between individuals. The differences in CL/F and CL₂/F between the phenotypes of CYP2C9 were approximately 36.5–51%. The difference in V/F between the phenotypes of OATP1B1 was approximately 41–64.6%. These results suggested that the phenotypes of CYP2C9 and OATP1B1 produced significant differences in torsemide PKs. Considering that CYP2C9 and OATP1B1 phenotypes as covariates affected different PK parameters of torsemide, it could be inferred that torsemide’s cell membrane permeation process by OATP1B1 and the metabolic process by CYP2C9 could independently affect each other in vivo without interplay. There was no significant difference in the parameter estimates between modeling software (Phoenix NLME vs. NONMEM). In this study, the torsemide PK variability between individuals was largely explained. In the future, individualized effective drug therapy of torsemide taking individual patient’s genotypes into account might become possible.

Toxicokinetic studies of di-isobutyl phthalate focusing on the exploration of gender differences in rats

Due to the use of di-isobutyl-phthalate (DiBP) in the production of soft-polyvinyl chloride articles, it is currently a hazardous substance prevalent in human daily life. However, reports on DiBP's toxicokinetics are still very scarce. And no studies have been reported on gender differences in DiBP toxicokinetics. Therefore, this study was conducted in accordance with these research needs. DiBP of 100 mg/kg has been exposed to male and female rats single or multiple times. DiBP and its major metabolite, mono-isobutyl-phthalate (MiBP), were quantified from various biological samples obtained from rats administered with DiBP. Based on these results, several toxicokinetic parameters were estimated. Toxicokinetic results between genders were compared, and from this, existence and extent of gender differences in DiBP's toxicokinetics were explored. Investigation of presence and extent of subacute toxicity in male and female rats following multiple exposures to DiBP were also conducted. This study provided comprehensive information on DiBP toxicity and gender differences that have not been reported in detail. Results of these studies imply that subacute toxicity in liver, kidney, lung, and testis of rats at 100 mg/kg of DiBP is modest and that there is little difference in toxicokinetics between genders. And in both male and female rats, the metabolism of DiBP (to MiBP) was significant, and excretion of MiBP into urine was a major indicator of DiBP exposure.

Toxicokinetics of di-isodecyl phthalate and its major metabolites in rats through the application of a developed and validated UHPLC-ESI-MS/MS method

Di-isodecyl phthalate (DiDP) is a high-molecular-weight phthalate that is mainly used as a plasticizer for plastics. Therefore, exposure to DiDP in the environment has become common with the increasing use of plastics around the world. Environmental regulations and scientific risk management for DiDP, which can be associated with endocrine disruption and various metabolic diseases, are urgently needed. The purpose of this study was to provide useful reference material for future human DiDP risk assessments by conducting toxicokinetic studies on DiDP. Rats were given 100 mg/kg of DiDP orally or intravenously, and plasma, urine, feces, and various tissues were sampled at preset times. DiDP and its major metabolites mono-isodecyl-phthalate (MiDP), mono-hydroxy-isodecyl-phthalate (MHiDP), mono-carboxy-isononyl-phthalate (MCiNP), and mono-oxo-isodecyl-phthalate (MOiDP) were simultaneously quantified from collected biological samples through the application of a newly developed and verified ultrahigh-performance liquid chromatography-electrospray ionization-tandem mass spectrometer (UHPLC-ESI-MS/MS) method. Based on the quantitative results for each analyte, toxicokinetic analyses were performed. DiDP was rapidly and extensively metabolized to MiDP, MHiDP, MCiNP, and MOiDP. The major metabolite excreted in the urine was MCiNP, suggesting that it could be a useful biomarker. The conjugated forms of DiDP and its metabolites have been significantly quantified in the plasma, urine, and feces. DiDP and its major metabolites were also distributed in various tissues in significant quantities. The toxicokinetic properties of DiDP, which have not been clearly reported previously, were identified through this study. This report will serve as a useful reference for future DiDP environmental regulation and scientific human risk assessment studies.

Simultaneous determination of fourteen components of Gumiganghwal-tang tablet in human plasma by UPLC-ESI-MS/MS and its application to pharmacokinetic study

Gumiganghwal-tang is a traditional herbal medicine widely used for its anti-inflammatory, analgesic, and antipyretic effects. However, the safety and efficacy of its active ingredients based on an in vivo pharmacokinetic (PK) study have yet been investigated. We have established a sensitive and accurate UPLC-ESI-MS/MS method and conducted a PK study on 14 constituents of Gumiganghwal-tang through human plasma analysis. Analytical conditions were optimized according to the physicochemical properties of the 14 compounds to facilitate efficient separation and eliminate overlap or interference between peaks. KINETEX-C₁₈ and Inertsil-C₈ columns were used as UPLC stationary phases, and acetonitrile and aqueous formic acid were used as mobile phases. All the analytes were quantified with a triple quadrupole mass spectrometer using electrospray ionization in multiple reaction monitoring mode. The chromatograms of 14 bioactive compounds showed excellent elution and sensitivity, and each peak was selectively separated and quantified without interference with each other or impurities. The established analytical method was based on international guidelines and was successfully used to perform PK studies of 14 herbal ingredients in humans after oral administration with Gumiganghwal-tang tablets. The oral absorption of most active components of Gumiganghwal-tang was relatively rapid and remained considerably long in the body to be quantified in plasma up to 48 h after administration.

Pharmacokinetic Comparison between Methotrexate-Loaded Nanoparticles and Nanoemulsions as Hard- and Soft-Type Nanoformulations: A Population Pharmacokinetic Modeling Approach

The purpose of this study was to identify and explore the differences in pharmacokinetics between different nanoformulations. This was done by comparing the pharmacokinetics of methotrexate-loaded nanoparticles [poly(lactic-co-glycolic acid); size of 163.70 ± 10.25 nm] and nanoemulsions (olive oil and Labrasol; size of 173.77 ± 5.76 nm), which represent hard- and soft-type nanoformulations, respectively. In addition, the population pharmacokinetic modeling approach as a useful tool for the comparison of pharmacokinetics between nanoformulations was newly proposed through this study. Significant pharmacokinetic differences were identified between nanoformulations through the new population pharmacokinetic modeling approach. As a result, the formulation type was explored as a significant covariate. The clearance and bioavailability of methotrexate-loaded nanoemulsions tended to decrease by 99% and increase by 19%, respectively, compared to those of the nanoparticles. The exploration of significant pharmacokinetic differences between drug formulations and their correlations presented in this study provide new perspectives on the development of nanoformulations.

Airway Epithelial Cells Drive Airway Smooth Muscle Cell Phenotype Switching to the Proliferative and Pro-inflammatory Phenotype

The increased mass of airway smooth muscle (ASM) in the airways of asthmatic patients may contribute to the pathology of this disease by increasing the capacity for airway narrowing. Evidence for the airway epithelium as a participant in ASM remodeling is accruing. To investigate mechanisms by which airway epithelial cells induce ASM cell (ASMC) proliferation, we have employed a co-culture model to explore markers of ASMC proliferative phenotype. Co-culture with epithelial cells led to incorporation of bromodeoxyuridine into ASMCs, indicating augmented proliferation and an associated increase in mRNA of the pro-proliferative co-transcription factor Elk1. Although the mitogen heparin-binding epidermal growth factor (HB-EGF) was augmented in the co-culture supernatant, the ASMC epidermal growth factor receptor (EGFR), an effector of HB-EGF induced proliferation, did not mediate epithelial-induced proliferation. The co-culture increased the expression of ASMC mRNA for the pro-inflammatory cytokines IL-6 and IL-8 as well as the pro-proliferative microRNA miR-210. The transcriptional repressor Max-binding protein (Mnt), a putative target of miR-210, was transcriptionally repressed in co-cultured ASMCs. Together, these data indicate that the airway epithelium-induced proliferative phenotype of ASMCs is not driven by EGFR signaling, but rather may be dependent on miR210 targeting of tumor suppressor Mnt.

Population Pharmacokinetic Analysis of Cefaclor in Healthy Korean Subjects

The aims of this study were: (1) to perform population pharmacokinetic analysis of cefaclor in healthy Korean subjects, and (2) to investigate possible effects of various covariates on pharmacokinetic parameters of cefaclor. Although cefaclor belongs to the cephalosporin family antibiotic that has been used in various indications, there have been very few population studies on factors affecting its pharmacokinetics. Therefore, this study is very important in that effective therapy could be possible through a population pharmacokinetic study that explores effective covariates related to cefaclor pharmacokinetic diversity between individuals. Pharmacokinetic results of 48 subjects with physical and biochemical parameters were used for the population pharmacokinetic analysis of cefaclor. A one-compartment with lag-time and first-order absorption/elimination was constructed as a base model and extended to include covariates that could influence between-subject variability. Creatinine clearance and body weight significantly influenced systemic clearance and distribution volume of cefaclor. Cefaclor’s final population pharmacokinetic model was validated and some of the population’s pharmacokinetic diversity could be explained. Herein, we first describe the establishment of a population pharmacokinetic model of cefaclor for healthy Koreans that might be useful for customizing cefaclor or exploring additional covariates in patients.

Oral delivery of topotecan in polymeric nanoparticles: Lymphatic distribution and pharmacokinetics

There have been many attempts to formulate a variety of drugs in nano-size formulations. However, biodistribution characteristics of these formulated drugs remain unclear. Information about the pharmacokinetics and distributions of these formulations is essential for future practical use and advanced formulation development. Topotecan is a useful agent for treating a variety of cancers. It exhibits anti-cancer activity by inhibiting topoisomerase. However, oral bioavailability of topotecan was not satisfactory in previous studies. Reversible hydrolysis of its active site according to pH environment was a major limitation in terms of treatment. To improve the bioavailability and retention of topotecan in target organs (such as lung and brain) and increase its delivery to the lymphatic system as a major pathway for cancer metastasis, this study was conducted on topotecan-loaded nanoparticles using poly(lactic-co-glycolic acid) (PLGA). These nanoparticles were prepared by double emulsion solvent evaporation. Formulated topotecan-loaded PLGA nanoparticles were subjected to several in vitro tests to determine various physicochemical properties such as size, zeta potential, encapsulation efficiency, morphology, and release profile. These nanoparticles were also subjected to in vivo studies using rats. Based on in vivo results, pharmacokinetic properties, distribution in the body, and delivery efficiency of these formulated nanoparticles were confirmed. Topotecan-loaded PLGA nanoparticles showed a delayed release pattern in vitro. Their pharmacokinetic profiles and distributions in the body were clearly different from those of free topotecan hydrochloride. Results confirmed that topotecan encapsulated in the PLGA polymer was stable from hydrolysis and present in an active form for a longer time in the body. Biometric imaging revealed in vivo properties of topotecan-loaded PLGA nanoparticles for qualitative confirmation. And oral delivery of topotecan in polymeric nanoparticles to lymph and various body tissues has been identified. Findings of this study indicate that topotecan formulated into nanoparticles (using PLGA) has a better pharmacokinetic profile and a better delivery to lymphoid tissues, lung, and brain than free topotecan hydrochloride, suggesting that these topotecan-loaded PLGA nanoparticles might provide better therapeutic results.

The complete chloroplast genome of Bupleurum euphorbioides, a traditional medicinal plant

Bupleurum euphorbioides is a rare native plant attributed with analgesic, gallbladder-supportive, and other functions in China and the Republic of Korea. However, the complete chloroplast genome sequence of the native plant B. euphorbioides has not been determined. In this study, we sequenced the complete chloroplast genome sequence, and examined the molecular phylogeny and genetic information of B. euphorbioides. The total chloroplast genome of B. euphorbioides was 154,871 bp in length with a large single-copy region (85,089 bp), small single-copy region (17,714 bp), and pair of inverted repeats regions (26,034 bp). The chloroplast genome encoded a total of 176 genes, including 131 protein-coding genes, 37 tRNA genes, and eight rRNA genes. The phylogenetic tree indicated that B. euphorbioides was the most closely related to B. latissimum.

Pharmacokinetic Changes According to Single or Multiple Oral Administrations of Socheongryong-Tang to Rats: Presented as a Typical Example of Changes in the Pharmacokinetics Following Multiple Exposures to Herbal Medicines

The purpose of this study was to investigate the pharmacokinetic properties of ephedrine, paeoniflorin, and cinnamic acid after single or multiple doses of Socheongryong-tang (SCRT) were administered to rats, and to present an example of the pharmacokinetic changes following multiple doses of an herbal medicine. SCRT is a traditional herbal medicine that has been used clinically for a long time, and its main ingredients include ephedrine, paeoniflorin, and cinnamic acid. However, studies on the pharmacokinetic properties of SCRT are insufficient, and particularly, no pharmacokinetic information has been reported for multiple doses. In this study, SCRT was administered orally to rats once or multiple times, and plasma sampled at different times was quantitatively analyzed for ephedrine, paeoniflorin, and cinnamic acid using ultra-high-performance liquid chromatography-tandem mass spectrometry. There was a difference between the pharmacokinetic parameter values of each component (especially in paeoniflorin and cinnamic acid) obtained after single or multiple doses of SCRT. The actual observed values of each component obtained after multiple doses of SCRT were clearly different from the predicted results of multiple-dose simulations based on the pharmacokinetic profiles obtained after a single dose. The results confirmed that the plasma concentrations and, thus, exposures to paeoniflorin and cinnamic acid were significantly increased when SCRT was administered multiple times, whereas that of ephedrine was not. The results of this study are expected to provide useful pharmacokinetic data for the safety and efficacy evaluation of SCRT in the future and demonstrate the necessity of pharmacokinetic comparison studies according to single or multiple oral administrations of herbal medicines.

Characteristics and phylogenetic analysis of the complete chloroplast genome of Paeonia japonica (Paeoniaceae)

Paeonia japonica, distributed throughout Asia, is a traditional medicinal herb in Korea, with many potential beneficial effects including pain-relieving, anti-inflammatory, and anti-cancer activities. Despite its high pharmacological value, the genetic information on Paeonia japonica remains limited. In this study, the chloroplast genome of P. japonica was sequenced using next-generation sequencing (NGS) technology and genome and phylogeny were analyzed using multiple tools. The chloroplast genome of P. japonica was 152,731 bp in length with an inverted repeat region of 26,656 bp, including a large single-copy region of 84,389 bp and a small single copy region of 17,030 bp. The P. japonica chloroplast genome included 113 genes comprising 80 protein-coding genes, 27 tRNA, and 5 rRNA genes. Phylogenetic analysis indicated that P. japonica and P. obovata share a close evolutionary relationship.

The complete chloroplast genome of Bupleurum euphorbioides, a traditional medicinal plant

Bupleurum euphorbioides is a rare native plant attributed with analgesic, gallbladder-supportive, and other functions in China and the Republic of Korea. However, the complete chloroplast genome sequence of the native plant B. euphorbioides has not been determined. In this study, we sequenced the complete chloroplast genome sequence, and examined the molecular phylogeny and genetic information of B. euphorbioides. The total chloroplast genome of B. euphorbioides was 154,871 bp in length with a large single-copy region (85,089 bp), small single-copy region (17,714 bp), and pair of inverted repeats regions (26,034 bp). The chloroplast genome encoded a total of 176 genes, including 131 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. The phylogenetic tree indicated that B. euphorbioides was most closely related to B. latissimum.

In vivo and in vitro studies of Banhahoobak-tang tablets using UPLC-ESI-MS/MS with polarity switching

Banhahoobak-tang is the most prescribed herbal drug in East Asia when individuals experience sudden symptoms such as sore throat or neurological symptoms. The low toxicity and high in-vivo safety of this herbal medicine has made it more attractive to patients, and it has recently been formulated as tablets. In addition, Banhahoobak-tang tablets are registered as health insurance drugs in South Korea, and clinical prescriptions and demand are increasing. However, there are very few clinical trial data as well as very little accurate content analysis and results for Banhahoobak-tang tablets. The purpose of this study was to perform in-vitro and in-vivo studies on Banhahoobak-tang tablets, including content analysis, pharmacokinetics in humans, and plasma protein binding. For this study, a UPLC-ESI-MS/MS method with polarity switching was developed for simultaneous analysis of 18 components of Banhahoobak-tang. To separate the analytes, a C₈ reverse-phase column was used as the stationary phase, 0.1 % aqueous formic acid and acetonitrile as the mobile phase, and ionization and multiple reaction monitoring for quantification. The developed method was able to isolate and quantify the 18 components with good sensitivity and selectivity and was fully validated according to international analytical standards. Stability tests were also conducted on the analytes. Finally, the method was applied to in-vitro and in-vivo studies of Banhahoobak-tang tablets, and the tablet components were 52.49 ng/g to 91.00 μg/g on average. The detected components showed rapid oral absorption in humans as well as high plasma protein binding ratio overall. These results and methods can be useful not only for effectiveness and safety evaluation but also for quality control of Banhahoobak-tang tablets.

Splenic infarction and infectious diseases in Korea

Background

The spleen contains immune cells and exhibits a pattern of infarction different from other organs; as such, splenic infarction (SI) may provide important clues to infection. However, the nature of the relationship between SI and infectious disease(s) is not well understood. Accordingly, this retrospective study investigated the relationship between SI and infection.

Methods

Hospital records of patients with SI, who visited Inha University Hospital (Incheon, Republic of Korea) between January 2008 and December 2018, were reviewed. Patient data regarding clinical presentation, causative pathogens, risk factors, and radiological findings were collected and analyzed.

Results

Of 353 patients with SI, 101 with infectious conditions were enrolled in this study, and their data were analyzed to identify associations between SI and infection. Ten patients were diagnosed with infective endocarditis (IE), and 26 exhibited bacteremia without IE. Twenty-seven patients experienced systemic infection due to miscellaneous causes (negative result on conventional automated blood culture), including the following intracellular organisms: parasites (malaria [n = 12], babesiosis [n = 1]); bacteria (scrub typhus [n = 5]); viruses (Epstein–Barr [n = 1], cytomegalovirus [n = 1]); and unidentified pathogen[s] (n = 7). Splenomegaly was more common among patients with miscellaneous systemic infection; infarction involving other organs was rare. Thirty-eight patients had localized infections (e.g., respiratory, intra-abdominal, or skin and soft tissue infection), and most (35 of 38) had other risk factors for SI.

Conclusions

In this study, various infectious conditions were found to be associated with SI, and intracellular organisms were the most common causative pathogens. Further studies are needed to examine other possible etiologies and the underlying pathophysiological mechanisms.

Simultaneous determination of asarinin, β-eudesmol, and wogonin in rats using ultraperformance liquid chromatography-tandem mass spectrometry and its application to pharmacokinetic studies following administration of standards and Gumiganghwal-tang

Asarinin, β-eudesmol, and wogonin have common antiangiogenic activities and have the potential for use in chemotherapy. Besides, they are multivalent substances that are combined in various herbal medicines. The purpose of this study was to develop a method for simultaneous analysis of asarinin, β-eudesmol, and wogonin, which are representative pharmacological components of Asarum heterotropoides, Atractylodes lancea, and Scutellaria baicalensis, respectively, in rat biosamples using ultraperformance liquid chromatography-tandem mass spectrometry. The three components were separated using 5 mm aqueous ammonium acetate containing 0.1% formic acid and acetonitrile as a mobile phase, equipped with a KINETEX core-shell C₁₈ column. The analysis was quantitated on a triple-quadrupole mass-spectrometer employing electrospray ionization, and operated in the multiple reaction monitoring mode. The chromatograms showed high resolution, sensitivity, and selectivity with no interference with plasma, urine, and feces constituents. The developed analytical method satisfied international guidance criteria and could be successfully applied to the pharmacokinetic (PK) studies evaluating oral bioavailability of asarinin, β-eudesmol, and wogonin after oral and intravenous administration and their urinary and fecal excretion ratios after oral administration to rats. Furthermore, the analysis was extended to PK studies following oral administration of Gumiganghwal-tang. This study was the first simultaneous analysis of the aforesaid three constituents in rat plasma, urine, and feces that also determined their PK parameters.

Irisin promotes odontogenic differentiation and angiogenic potential in human dental pulp cells

AIM

To determine whether irisin, a newly discovered myokine that links exercise-induced and metabolic homeostasis, is able to promote odontogenic differentiation and angiogenesis in human dental pulp cells (HDPCs).

METHODOLOGY

Cell viability in the presence of irisin was measured. Real-time PCR and Western blot analysis were performed to evaluate the expression levels of irisin, odontogenic and angiogenic markers. The involvement of mitogen-activated protein kinase (MAPK) and the protein kinase B (Akt) signalling pathway was evaluated by Western blot. To evaluate mineralization nodule formation, alkaline phosphatase (ALP) staining and alizarin red S staining were performed. Scratch wound assays were performed to evaluate the effects of irisin on cell migration. The data were analysed using one-way analysis of variance (anova) followed by Tukey post hoc test and Student's t-test. Statistical significance was considered at P < 0.05.

RESULTS

Irisin significantly promoted odontogenic differentiation as evidenced by formation of mineralized nodules, induction of ALP activity and upregulation of odontogenic and angiogenic markers (P < 0.05). Scratch wound assays revealed that irisin significantly increased migration of HDPCs (P < 0.05). Phosphorylation of both MAPK and Akt was increased by irisin. MAPK and Akt inhibitors inhibited mineralization, cell migration and the increased expression of odontogenic and angiogenic markers.

CONCLUSIONS

Irisin promoted odontogenic differentiation and mineralization and has the potential for angiogenesis through activation of the MAPK and Akt signalling pathways in HDPCs.

A 13-week repeated oral dose toxicity evaluation and a 4-week recovery evaluation of the Sam So Eum (SSE) in male and female rats

ETHNOPHAMACOLOGICAL RELEVANCE

Sam So Eum (SSE), used in traditional Korean medicine, has been prescribed for the treatment of various ailments including emesis, and fever for centuries. SSE is known by several different names (Shen Su Yin in traditional Chinese medicine; Jin So In traditional Japanese Kampo medicine). It is a mixture of medicinal plants including Panax ginseng C. A. Mey., Perilla frutescens (L.) Britton, and Peucedanum praeruptorum Dunn. Studies have revealed that SSE has many pharmacological effects including anti-inflammatory, anti-cancer, and anti-allergic properties, but its toxic effects have not been evaluated in vivo. Recently, the use of traditional medicinal herbs to treat various diseases has increased, owing to increased number of studies supporting their efficacy. However, safety evaluations for toxicity and other adverse effects have not been extensive. It is commonly considered that natural products extracted from traditional medicinal herbs are safer than synthetic drugs, but this lacks a scientific basis. Thus, in this study, we evaluated the toxicity of SSE in male and female rats.

AIM OF THE STUDY

To evaluated the safety of SSE in male and female rats.

MATERIALS AND METHODS

SSE was administered orally for 13 weeks at 1000, 2000, and 4000 mg kg^-1·day^-1, and then the rats were maintained for 4 weeks without SSE administration (recovery evaluation).

RESULTS

We observed the animals for changes in clinical signs, including hematological parameters, and food consumption; serum chemistry profiling and urinalysis were also carried out. Creatinine levels in the serum were significantly increased following oral administration of SSE at 2000 and 4000 mg kg^-1·day^-1 in male and female rats, but returned to the normal levels during the recovery period. In addition, SSE administration does not cause kidney and liver toxicity. Thus, we determined that the no-observed-adverse-effect level of SSE is 4000 mg kg^-1·day^-1. The no-observed-effect level of SSE was determined to be 1000 mg kg^-1·day^-1, because serum creatinine was increased by oral administration of SSE at 2000 and 4000 mg kg^-1·day^-1 in male and female rats.

CONCLUSIONS

SSE administration does not cause toxicity at 4000 mg kg^-1·day^-1 in male and female rats.

Simultaneous determination of three iridoid glycosides of Rehmannia glutinosa in rat biological samples using a validated hydrophilic interaction-UHPLC-MS/MS method in pharmacokinetic and in vitro studies

The purpose of this study was to develop a method for simultaneous analysis of aucubin, catalpol, and geniposide, which are representative iridoid glycoside constituents of Rehmannia glutinosa, in rat plasma, urine, and feces using hydrophilic interaction ultra high-performance liquid chromatography with tandem mass spectrometry. The three components were separated using 10 mmol/L aqueous ammonium formate containing 0.01% (v/v) formic acid and acetonitrile as a mobile phase by gradient elution at a flow rate of 0.2 mL/min, equipped with a Kinetex^® HILIC column (50 × 2.1 mm, 2.6 μm). Quantitation of this analysis was performed on a triple quadrupole mass spectrometer employing electrospray ionization and operated in multiple reaction monitoring mode. The chromatograms showed high resolution, sensitivity, and selectivity with no interference with plasma constituents. In all three iridoid glycosides, both the intra- and interbatch precisions (coefficient of variation %) were less than 4.81%. The accuracy was 96.56-103.55% for aucubin, 95.23-106.21% for catalpol, and 94.50-104.16% for geniposide. The developed analytical method satisfied the criteria of international guidance and was successfully applied to pharmacokinetic studies including oral bioavailability of aucubin, catalpol, and geniposide, and their urinary and fecal excretion ratios after oral or intravenous administration to rats. The new method was also applied to measure plasma protein binding ratios in vitro.

Ivabradine-Induced Torsade de Pointes in Patients with Heart Failure Reduced Ejection Fraction

Ivabradine is a selective inhibitor of the sinoatrial node "funny" current, prolonging the slow diastolic depolarization. As it has the ability to block the heart rate selectively, it is more effective at a faster heart rate. It is recommended for the treatment of heart failure reduced ejection fraction in the presence of beta-blocker therapy for the further reduction of the heart rate. However, previous reports have shown the association of Torsade de pointes (TdP) with concurrent use of ivabradine and drugs resulting in QT prolongation or blockage of the metabolic breakdown of ivabradine. In this article, we report two cases of patients with heart failure reduced ejection fraction who developed TdP after ivabradine use. Our report highlights the need to exercise caution with the administration of ivabradine in the presence of a reduced repolarization reserve, such as QT prolongation or metabolic insufficiency.

Pharmacokinetic Comparison of Three Different Administration Routes for Topotecan Hydrochloride in Rats

Topotecan is actively used in clinic, with its primary use being in treatment of various types of cancer. The approved administration routes are oral and intravenous. The purpose of this study was to investigate and identify pharmacokinetic profiles of different administration routes. We conducted pharmacokinetic studies on three different routes of administration in rats. Five rats in each group received a single dose of 4 mg/kg of topotecan hydrochloride intravenously, orally, or subcutaneously, and the concentrations of lactone and total forms of the drug in plasma, urine, and feces were quantified. Various pharmacokinetic parameters were compared statistically. Plasma concentrations of both the lactone and total forms at elimination phase following subcutaneous administration, were two times higher than was seen with oral administration and 10 times higher than with intravenous administration. Subcutaneous administration of topotecan showed pharmacokinetic profiles similar to sustained release. In addition, subcutaneous administration showed bioavailability from 88.05% (for lactone form) to 99.75% (for total form), and these values were four–five times greater than those of oral administration. The results of this non-clinical study will not only provide greater understanding of the in vivo pharmacokinetics of topotecan, but also be useful for development of additional formulations and/or administration routes.

Characterization of the complete chloroplast genome of Liriope platyphylla (Asparagaceae: Nolinoideae) isolated in Korea

Liriope platyphylla is used as an important medicinal plant for fatigue, cough, and inflammation in South Korea. Here, we report the complete chloroplast genome of L. platyphylla. The total genome size of the chloroplast is 157,076 bp with a large single-copy region (LSC: 85,374 bp), a small single-copy region (SSC: 18,748 bp), and inverted repeat regions (IRa and IRb: 26,477 bp). The GC content of the L. platyphylla chloroplast was 37.6%. The cp genome encoded a set of 129 genes, including 83 protein-coding genes, 38 tRNA genes, and 8 rRNA genes. The phylogenetic tree analysis indicated that L. platyphylla is closely related to L. spicata.

Pharmacokinetic comparison with different assays for simultaneous determination of cis-, trans-cefprozil diastereomers in human plasma

The purpose of this study was to compare pharmacokinetic (PK) parameters obtained using two newly developed assays, HPLC-UV and UPLC-ESI-MS/MS. Selection of assay and results obtained therefrom are very important in PK studies and can have a major impact on the PK-based clinical dose and usage settings. For this study, we developed two new methods that are most commonly used in biosample analysis and focused on PK parameters obtained from them. By HPLC-UV equipped with a Luna-C₈ column using UV detector, cefprozil diastereomers were separated using water containing 2% (V/V) acetic acid and acetonitrile as a mobile phase. By UPLC-ESI-MS/MS equipped with a HALO-C₁₈column, cefprozil diastereomers were separated using 0.5% (V/V) aqueous formic acid containing 5 mM ammonium-formate buffer and methanol as a mobile phase. Chromatograms showed high resolution, sensitivity, and selectivity without interference by plasma constituents. Both intra- and inter-day precisions (CV, %) were within 8.88% for HPLC-UV and UPLC-ESI-MS/MS. Accuracy of both methods was 95.67%–107.50%. These two analytical methods satisfied the criteria of international guidance and could be successfully applied to PK study. Comparison of PK parameters between two assays confirmed that there is a difference in the predicted minimum plasma concentrations at steady state, which may affect clinical dose and usage settings. Furthermore, we confirmed possible correlation between PK parameters and various biochemical parameters after oral administration of 1000 mg cefprozil to humans.

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Development of UPLC-ESI-MS/MS and HPLC-UV methods for cefprozil diastereomers.

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Comparison of PK parameters obtained using two newly developed assays.

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Possible correlation between PK parameters and various biochemical parameters.

An analysis of vascular properties using pulse wave analysis in patients with vasovagal syncope

BACKGROUND

Vasovagal syncope (VVS) is a common cause of recurrent syncope. Nevertheless, the exact hemodynamic mechanism has not been elucidated. Pulse wave analysis (PWA) is widely used to evaluate vascular properties, as it reflects the condition of the entire arterial system.

HYPOTHESIS

Cardiovascular autonomic modulation may influence the hemodynamic mechanism and result in different vascular properties between VVS patients and healthy individuals.

METHODS

We enrolled consecutive patients diagnosed with VVS on head-up tilt testing from January 2014 to August 2019. Healthy subjects were enrolled as the control group. We performed PWA on all participants. Using propensity score matching, we assembled a study population with similar baseline characteristics and compared hemodynamic parameters.

RESULTS

A total of 111 VVS patients (43 ± 18 years, 72 females) and 475 healthy control subjects (48 ± 13 years, 192 females) were enrolled. Compared to the healthy control subjects, the VVS patients had a higher augmentation index (AIx) adjusted to a heart rate of 75 beats per minute (AIx@HR75, 20.5 ± 13.1% vs 16.7 ± 11.9%, P = .003). After 1:1 matched comparison (111 matched control), VVS patients consistently showed higher AIx@HR75 (20.5 ± 13.1% vs 16.7 ± 12.9%, P = .02) than the matched control group. According to age distribution, VVS patients showed significantly higher AIx@HR75 (10.6 ± 11.7% vs 2.5 ± 11.1%, P = .01) in a young age (15-33 years) group.

CONCLUSIONS

VVS patients had greater arterial stiffness than healthy subjects. This is one of the plausible mechanisms of the pathophysiology of VVS.

Population Pharmacokinetic Analysis of Tiropramide in Healthy Korean Subjects

The purpose of this study was to perform population pharmacokinetic (PPK) analysis of tiropramide in healthy Korean subjects, as well as to investigate the possible effects of various covariates on pharmacokinetic (PK) parameters of tiropramide. Although tiropramide is commonly used in digestive system-related diseases as an antispasmodic, PPK reporting and factors affecting PKs are not clearly reported. Thus, this study for healthy subjects is very significant because it could find new covariates in patients that had not been reported before or predict PPK for patients in the clinic by establishing PPK in healthy adults. By using Phoenix NLME, PK, demographic, and genetic data (collected to explain PK diversity of tiropramide in population) analyses were performed. As a basic model, a one-compartment with first-order absorption and lag-time was established and extended to include covariates that influenced the inter-subject variability. The total protein significantly influenced the distribution volume and systemic clearance of tiropramide, but genetic factors such as ABCB1 (1236C>T, 2677G>T/A, and 3435C>T), CYP2D6 (*1 and *10), OCT2 (808G>T), and PEPT1 (1287G>C) genes did not show any significant association with PK parameters of tiropramide. The final PPK model of tiropramide was validated, and suggested that some of the PK diversity in the population could be explained. Herein, we first describe the establishment of the PPK model of tiropramide for healthy Korean subjects, which may be useful as a dosing algorithm for the diseased population.

Risk assessment for humans using physiologically based pharmacokinetic model of diethyl phthalate and its major metabolite, monoethyl phthalate

Diethyl phthalate (DEP) belongs to phthalates with short alkyl chains. It is a substance frequently used to make various products. Thus, humans are widely exposed to DEP from the surrounding environment such as food, soil, air, and water. As previously reported in many studies, DEP is an endocrine disruptor with reproductive toxicity. Monoethyl phthalate (MEP), a major metabolite of DEP in vivo, is a biomarker for DEP exposure assessment. It is also an endocrine disruptor with reproductive toxicity, similar to DEP. However, toxicokinetic studies on both MEP and DEP have not been reported in detail yet. Therefore, the objective of this study was to evaluate and develop physiologically based pharmacokinetic (PBPK) model for both DEP and MEP in rats and extend this to human risk assessment based on human exposure. This study was conducted in vivo after intravenous or oral administration of DEP into female (2 mg/kg dose) and male (0.1-10 mg/kg dose) rats. Biological samples consisted of urine, plasma, and 11 different tissues. These samples were analyzed using UPLC-ESI-MS/MS method. For DEP, the tissue to plasma partition coefficient was the highest in the kidney, followed by that in the liver. For MEP, the tissue to plasma partition coefficient was the highest in the liver. It was less than unity in all other tissues. Plasma, urine, and fecal samples were also obtained after IV administration of MEP (10 mg/kg dose) to male rats. All results were reflected in a model developed in this study, including in vivo conversion from DEP to MEP. Predicted concentrations of DEP and MEP in rat urine, plasma, and tissue samples using the developed PBPK model fitted well with observed values. We then extrapolated the PBPK model in rats to a human PBPK model of DEP and MEP based on human physiological parameters. Reference dose of 0.63 mg/kg/day (or 0.18 mg/kg/day) for DEP and external doses of 0.246 μg/kg/day (pregnant), 0.193 μg/kg/day (fetus), 1.005-1.253 μg/kg/day (adults), 0.356-0.376 μg/kg/day (adolescents), and 0.595-0.603 μg/kg/day (children) for DEP for human risk assessment were estimated using Korean biomonitoring values. Our study provides valuable insight into human health risk assessment regarding DEP exposure.

Pharmacokinetic Comparison of Epinastine Using Developed Human Plasma Assays

The purpose of the study was to develop two new methods, HPLC-UV and UPLC-MS/MS, for quantifying epinastine in human plasma and to compare pharmacokinetic (PK) parameters obtained using them. Even in the same sample, there may be a difference in the quantitative value of drug depending on the assay, so that minor changes in PK parameter values may affect drug dose and usage settings. Therefore, selection and establishment of analytical methods are very important in PK studies of drugs, and a comparison of PK parameters according to analytical methods will be vital. For this study of PK parameter change, we newly developed two methods, HPLC-UV and UPLC-MS/MS, which are most commonly used to quantify epinastine concentrations in human plasma. All developed methods satisfied the international guidelines and criteria for successful application to PK study of 20 mg epinastine hydrochloride tablets after oral administration to twenty-six humans. A comparison of these two methods for in vivo analysis of epinastine was performed for the first time. This comparison study confirmed that different dose and usage settings might be possible based on PK parameters calculated using other analyses. Such changes in calculated PK parameters according to analytical methods would be crucial in the clinic.

Subchronic toxicity evaluation of ethanol extract of Cassia tora L. seeds in rats

Cassia tora Linn. is an annual or perennial plant of the Fabaceae/Leguminosae family. It is used in traditional medicine for various biological activities including anti-constipation, anti-inflammatory, visual acuity, and hepato-protective activities. The present study was carried out to investigate the potential toxicity of C. tora L. seed ethanol extract (CTSEE) following a 13-week repeated oral administration to Sprague-Dawley rats. CTSEE was administered orally to male and female rats for 13 weeks at 0 (control), 500, 1000, and 2000 mg/kg/day (n = 10, for male and female rats for each dose). Additional recovery groups from the control group and high dose group were observed for a 4-week recovery period. At the end of the treatment and recovery periods, animals were sacrificed, and their organs were weighed and blood samples collected. There were no treatment-related adverse effects in clinical signs, body weight, food consumption, estrous cycle, sperm parameters, urinalysis, hematology, serum biochemistry, necropsy findings, organ weight, and histopathology at any doses tested. Under the present experimental conditions, the no-observed-adverse-effect level of the CTSEE was >2000 mg/kg/day in both genders, and no target organs were identified.

Impact of gender on heart failure presentation in non-obstructive hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a genetic cardiac disease that represents a broad spectrum of morphologic features and clinical presentations. However, little is known about the impact of gender differences in heart failure (HF) development in non-obstructive HCM. We assessed clinical and echocardiographic parameters according to gender in patients with non-obstructive HCM and evaluated the impact of gender on HF presentation and cardiovascular (CV) outcomes in this population. We investigated 202 consecutive patients with non-obstructive HCM. Clinical parameters and conventional echocardiographic measurements including tissue Doppler measurements were evaluated and compared according to gender. Additionally, left ventricular (LV) deformation was assessed with global longitudinal strain (GLS) utilizing 2D speckle tracking software. Of the 202 patients (age = 63 ± 14 years, male: female = 141: 61), 51 patients (24.8%) presented with HF and female patients had HF more frequently (52.5% vs. 12.8%, P < 0.001). Females were older, had a higher prevalence of atrial fibrillation, had increased left atrial volume (LAV), and a higher ratio of early diastolic mitral inflow to early annular velocity (E/e') than males (70 ± 12 years vs. 59 ± 14 years, P < 0.001 for age; 51.4 ± 19.3 mL/m² vs. 40.0 [Formula: see text] 13.4 mL/m², P < 0.001 for indexed LAV; 17.2 [Formula: see text] 6.0 vs. 13.0 [Formula: see text] 4.3, P < 0.001 for E/e'). While LV maximal thickness and LV ejection fraction were comparable between men and women, GLS was decreased significantly in female patients (- 13.5 [Formula: see text] 3.4% vs. - 15.6 [Formula: see text] 4.0%, P = 0.001 for GLS). Even after adjusting for clinical factors, female was independently associated with HF presentation (Odd ratio 5.19, 95% CI 2.24-12.03, P < 0.001). During a median follow-up duration 34.0 months, 20 patients (9.9%) had HF hospitalization or CV death. In a multivariable analysis, female gender was associated with higher risk of the composite of HF hospitalization or CV death and HF hospitalization alone than male (Adjusted hazard ratio [HR] = 3.31, 95% CI 1.17-9.35, P = 0.024 for primary composite outcome of HF hospitalization or CV death; adjusted HR = 4.78, 95% CI 1.53-14.96, P = 0.007 for HF hospitalization). In patients with non-obstructive HCM, female patients presented with HF more frequently and showed a higher risk of CV events than male patients. LA volume, E/e' and LV mechanics were different between the genders, suggesting that these might contribute to greater susceptibility to HF in women with HCM.