Simultaneous determination of trantinterol and its metabolites in rat urine and feces by liquid chromatography–tandem mass spectrometry

Bamboo shoot dietary fiber alleviates gut microbiota dysbiosis and modulates liver fatty acid metabolism in mice with high-fat diet-induced obesity

Introduction

Obesity is a common nutritional disorder characterized by an excessive fat accumulation. In view of the critical role of gut microbiota in the development of obesity and metabolic diseases, novel dietary therapies have been developed to manage obesity by targeting the gut microbiome. In this study, we investigated anti-obesity effects of bamboo shoot dietary fiber (BSDF) and the potential mechanisms.

Methods

After 12 weeks of intervention with BSDF in high-fat mice, we detected obesity-related phenotypic indicators, and made transcriptomic analysis of liver tissue. Then we analyzed the changes of gut microbiota using 16S rRNA gene sequencing, explored the effect of BSDF on gut microbiota metabolites, and finally verified the importance of gut microbiota through antibiotic animal model.

Results and discussion

We found that BSDF was effective in reducing lipid accumulation in liver and adipose tissue and alleviating dyslipidemia and insulin resistance. Liver transcriptome analysis results showed that BSDF could improve lipid metabolism and liver injury by modulating peroxisome proliferator-activated receptor (PPAR) and fatty acid metabolic pathways. The 16S rRNA gene sequencing analysis of gut microbiota composition showed that BSDF significantly enriched beneficial bacteria such as Bifidobacterium, Akkermansia, Dubosiella, and Alloprevotella. Analysis of fecal metabolomics and gut microbiota metabolites revealed that BSDF increased the levels of several short-chain fatty acids and enriched bile acids, which may be important for improving lipid metabolism. Notably, the obesity-related metabolic disorders were abrogated after the abrogation of gut microbiota, suggesting that gut microbiota is a key factor in the beneficial effects of BSDF.

Conclusion

Our study suggests that BSDF as a prebiotic supplement has the potential to improve obesity by improving gut microbiota and modulating host PPAR and fatty acid metabolic pathways.

Efficacy and safety of tratinterol hydrochloride tablets in bronchial asthma: a randomized double-blind and multicenter clinical trial

PURPOSE

The aim of this study was to investigate the efficacy and safety of tratinterol hydrochloride in bronchial asthma (BA) treatment.

METHODS

Patients enrolled in this study were distributed randomly into a treatment group (tratinterol hydrochloride) and an active control group (procaterol hydrochloride) and were treated for 2 weeks after running-in. The end points were changes in pulmonary function and clinical symptoms after administration. Safety indices were physical examinations, laboratory testing and spontaneous reporting.

FINDINGS

We enrolled 732 subjects, -365 in the treatment group and 367 in the active control group. Forced expiratory volume (FEV₁), significantly increased in both group after treatment (P < 0.05). Least-squares (LS) means were -0.03/in the full-analysis set (FAS) and -0.02 in the per-protocol set (PPS) set, and 95% confidence intervals (CIs) for these sets were -0.09 to 0.03 and -0.08 to 0.04, respectively. Forced expiratory volume (FVC), morning peak expiratory flow (PEF) and asthma scores were significantly different with pretreatment (P < 0.05). There was no difference in asymptomatic days or frequency of relief medicine use (P > 0.05). No serious adverse events occurred.

IMPLICATIONS

Tratinterol hydrochloride was effective, safe and not inferior to procaterol hydrochloride in treating BA.

Identification of the cytochrome P450 enzymes involved in the oxidative metabolism of trantinterol using ultra high-performance liquid chromatography coupled with tandem mass spectrometry

Trantinterol is a novel β₂-adrenoceptor agonist used for the treatment of asthma. This study aimed to identify the cytochrome P450 enzymes responsible for the metabolism of trantinterol to form 4-hydroxylamine trantinterol (M1) and tert-butyl hydroxylated trantinterol (M2), which was achieved using the chemical inhibition study, followed by the metabolism study of trantinterol in a panel of recombinant CYPs, as well as the kinetic study with the appropriate cDNA-expressed P450 enzymes. A highly selective and sensitive ultra high-performance liquid chromatography tandem mass spectrometry method was developed and validated for the simultaneous determination of M1 and M2. The inhibition study suggested that CYP2C19 and CYP3A4/5 were involved in the formation of M1 and M2, and CYP2D6 only contributed to the formation of M1. Assays with cDNA-expressed CYP enzymes further showed that the relative contributions of P450 isoforms were 2C19 > 3A4 > 2D6 > 2E1 for the formation of M1, and 3A4 > 2C19 > 2D6 for the formation of M2. The enzyme kinetic analysis was then performed in CYP2C19, CYP2D6 and CYP3A4. The kinetic parameters were determined and normalized with respect to the human hepatic microsomal P450 isoform concentrations. All the results support the conclusion that CYP3A4 and CYP2C19 are the major enzymes responsible for formation of M1 and M2, while CYP2D6 and CYP2E1 also engaged to a lesser degree. The results imply that potential drug–drug interactions may be noticed when trantinterol is used with CYP2C19 and CYP3A4 inducers or inhibitors, and we should pay attention to this phenomenon in clinical study.

The first report on the characterization of the main CYP450 enzymes and the kinetic study involved in trantinterol metabolism.

Chemical and biochemical characterization and in vivo safety evaluation of pharmaceuticals in drinking water

The water constituents that are currently subject to legal control are only a small fraction of the vast number of chemical substances and microorganisms that may occur in both the environment and water resources. The main objective of the present study was to study the health impact resulting from exposure to a mixture of pharmaceuticals that have been detected in tap water at low doses. Analyses of atenolol, caffeine, erythromycin, carbamazepine, and their metabolites in blood, urine, feces, fat tissue, liver, and kidney after exposure to a mixture of these pharmaceuticals in treated drinking water were performed. The effects of this exposure were assessed in rats by measuring biochemical markers of organ injury or dysfunction. Simultaneously, the selected pharmaceuticals were also quantified in both physiological fluids and organ homogenates by liquid chromatography-tandem mass spectrometry (performed in multiple reaction monitoring mode and full scan mode). Following exposure of rats to a concentration of a pharmaceutical which was 10 times higher than the concentration known to be present in tap water, trace levels of some pharmaceuticals and their metabolites were detected in biological samples. This exposure did, however, not lead to significant organ injury or dysfunction. Thus, the authors report an experimental model that can be used to characterize the safety profile of pharmaceuticals in treated drinking water using a multiorgan toxicity approach. Environ Toxicol Chem 2016;35:2674-2682. © 2016 SETAC.

Quantification of trantinterol, its two metabolites and their primary conjugated metabolites in human plasma by ultra-high-performance liquid chromatography-tandem mass spectrometry and its application to a pharmacokinetic study

A highly rapid, selective and sensitive ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed to simultaneously determine trantinterol, its major phase-I metabolites and their primary conjugated metabolites in human plasma. Waters Oasis HLB C18 solid phase extraction cartridges were used in the sample preparation. The separation was carried out on an ACQUITY UPLC™ BEH C18 column with methanol/0.2% formic acid (30:70, v/v) as the mobile phase at a flow rate of 0.25 mL/min. The detection was performed on a triple quadrupole tandem mass spectrometer in selective reaction monitoring (SRM) mode with the use of an electrospray ionization (ESI) source. The linear calibration curves for trantinterol, tert-butyl hydroxylated trantinterol (tert-OH-trantinterol) and 1-carbonyl trantinterol (trantinterol-COOH) were obtained in the concentration ranges of 0.200-250, 0.108-4.00 and 0.0840-5.02 ng/mL, respectively (r(2)≥0.99). The intra- and inter-day precision (relative standard deviation, RSD) values were less than 13%, and the accuracy (relative error, RE) was within ±9.9%, as determined from quality control (QC) samples for the analytes. The concentrations of conjugated forms of trantinterol and tert-OH- trantinterol in plasma were determined using selective enzyme hydrolysis. The method described herein was fully validated and successfully applied for the pharmacokinetic study of trantinterol in healthy volunteers after oral administration.

An LC-MS/MS method for simultaneous determination of trantinterol and its major metabolite in rat plasma and its application to a comparative pharmacokinetic study

Trantinterol is a novel β2-adrenoceptor agonist, currently undergoing clinical trials for the treatment of asthma. We developed and validated an liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for simultaneous determination of trantinterol and its major metabolite, 1-carbonyl trantinterol (SPFFCOOH), in rat plasma. Aliquots (100μL) of heparinized plasma samples were processed by protein precipitation with acetonitrile. Chromatographic separation used an Acquity UPLC BEH C18 column (2.1mm×50mm, 1.7μm) and acetonitrile-0.1% formic acid (20:80, v/v) as mobile phase, at a flow rate of 0.25mL/min. The detection was performed on a triple-quadrupole tandem mass spectrometer with multiple-reaction monitoring (MRM) mode via electrospray ionization (ESI) source. The precursor-to-product ion transitions m/z 310.9→m/z 237.9 for trantinterol, m/z 324.9→m/z 251.9 for SPFFCOOH and m/z 368.0→m/z 294.0 for bambuterol (internal standard, IS) were used for quantification. The calibration curves were obtained in the concentration of 0.25-100ng/mL for both trantinterol and SPFFCOOH. The intra- and inter-day precision (relative standard deviations, RSD) values were below 15% and accuracy (relative error, RE) was from -4.3% to 6.6% at all quality control (QC) levels. The method was successfully applied to compare the pharmacokinetics of trantinterol and SPFFCOOH in male and female Wistar rats after a single oral administration of trantinterol.

Randomized, Multicenter Clinical Study of Tratinterol Hydrochloride Tablets for the Treatment of Bronchial Asthma

PURPOSE

The aim of this study was to determine the efficacy and safety profile of tratinterol hydrochloride tablets in the treatment of bronchial asthma.

METHODS

This multicenter, randomized, double-blind clinical research study was completed at 6 centers in the People's Republic of China from March 2009 to June 2010, and a randomized trial of procaterol hydrochloride tablets produced by Otsuka Pharmaceutical Co Ltd was conducted. The study was approved by the Medical Ethics Committee of the First Hospital of China Medical University. The clinical trial registration number is 2007L04263.

FINDINGS

A total of 223 patients were selected for this study, with 112 patients in the treatment group and 111 in the control group. The lung function of the 2 groups after treatment significantly increased in all (P < 0.05); however, there was no significant difference in the changes between the 2 groups (P > 0.05). The occurrence of related adverse events at varying degrees in the control group was higher than in the treatment group.

IMPLICATIONS

It is safe and effective to use tratinterol hydrochloride tablets to treat bronchial asthma.

Determination of trantinterol enantiomers in human plasma by high-performance liquid chromatography - tandem mass spectrometry using vancomycin chiral stationary phase and solid phase extraction and stereoselective pharmacokinetic application

A sensitive and enantioselective vancomycin chiral stationary phase high-performance liquid chromatography-tandem mass spectrometry method was developed for the determination of trantinterol enantiomers in human plasma. Baseline resolution was achieved using the vancomycin chiral stationary phase known as Chirobiotic V with polar ionic mobile phase consisting of acetonitrile-methanol (60:40, v/v) containing 0.01% ammonia and 0.02% acetic acid at a flow rate of 1.0 mL/min. Waters Oasis HLB C18 solid phase extraction cartridges were used in the sample preparation of trantinterol samples from plasma. The detection was performed on a triple-quadrupole tandem mass spectrometer by multiple reaction monitoring mode via electrospray ionization. The calibration curve was linear in a concentration range from 0.0606 to 30.3 ng/mL in plasma, with the lower limit of quantification of 0.0606 ng/mL. The intra- and interday precision (relative standard deviation) values were within 9.7% and the accuracy (relative error) was from -6.6 to 7.2% at all quality control levels. The method was successfully applied to a study of stereoselective pharmacokinetics in human.

Simultaneous Determination of Trantinterol and One of Its Major Metabolites, 1-Carbonyl Trantinterol, in Human Plasma by LC-MS-MS

A highly selective and sensitive liquid chromatography-tandem mass spectrometry method was developed and validated for the simultaneous determination of trantinterol and one of its major metabolites, 1-carbonyl trantinterol, in human plasma. An Oasis MCX 96-well solid-phase extraction cartridge and a SeQuantTM ZIC(®)-HILIC LC column were used for sample preparation and chromatographic separation, respectively. The analytes were monitored by a QTrap 5500 mass spectrometer with positive electrospray ionization. Multiple reaction monitoring was used for quantification using the precursor to product ion pairs of m/z 311.1 → 237.9 (trantinterol), m/z 325.1 → 251.9 (1-carbonyl trantinterol) and m/z 368.4 → 294.0 (bambuterol as internal standard). The assay had a calibration range from 0.2 to 50 pg/mL and a lower limit of quantification of 0.2 pg/mL for both trantinterol and 1-carbonyl trantinterol. The inter-day and intra-day precisions were <12.0% and the accuracies were within the range of 87.1-111%. The mean recovery ranged from 82.0 to 97.7% and internal standard normalized matrix effect from 0.813 to 0.899. The analytes were stable under all tested conditions. This validated method was successfully applied to a pilot pharmacokinetic study in healthy subjects administered a single 50 μg oral dose.

Efficacy and tolerability of tratinterol hydrochloride tablets in bronchial asthma: a multicenter, randomized, double-blind, dose-finding clinical trial

PURPOSE

The aims of this study were to determine the efficacy and tolerability of different dosages of, and to identify the best dosage of, tratinterol hydrochloride tablets in the treatment of bronchial asthma.

METHODS

This multicenter, randomized, double-blind, dose-finding clinical research study was completed at 3 centers in the People's Republic of China from March 2008 to February 2009. Each center selected patients with bronchial asthma whose forced expiratory volume in 1 second (FEV1) values were <80% of predicted normal (pretreatment). Patients were assigned to 1 of 3 groups, based on daily dosage: low, 50 μg/d; intermediate, 100 μg/d; and high, 150 μg/d. Doses were administered orally twice daily for 10 days. The primary end points were the changes from baseline (0 minutes) in peak expiratory flow (PEF) and FEV1 at 30 minutes and 1, 2, 4, 6, and 12 hours after administration. Secondary end points were changes from baseline in forced vital capacity and asthma scores. Tolerability was monitored throughout the study period using physical examinations, laboratory testing, and spontaneous reporting.

FINDINGS

A total of 72 patients were selected in this study (24 per group; 40 men; 32 women; mean age, 43.48 years). The efficacy analysis (per-protocol set) included 20, 20, and 22 patients in the low-, intermediate-, and high-dosage groups, respectively. In terms of the primary and secondary end points, the intermediate dosage was most efficacious, followed by the high and low dosages, respectively. All 3 dosages were well-tolerated.

IMPLICATIONS

In these patients with bronchial asthma, 100 μg/d was the dosage of tratinterol hydrochloride tablets most efficacious in terms of improvement in lung function. All 3 dosages were well-tolerated.