Are the postmortem concentration changes of the synthetic cannabinoid cumyl-5F-P7AICA and its N-pentanoic acid metabolite dependent on the environmental conditions? - A systematic study following pulmonary administration to pigs.

The number of fatal cases involving synthetic cannabinoids (SCs) is increasing. However, interpretation of postmortem (PM) toxicological findings is challenging, due to unknown PM intervals and possible redistribution processes or instabilities. Only sparse data on SCs are available. Therefore, a controlled pig study was performed to determine the PM stability of cumyl-5F-P7AICA under different environmental conditions. Ten pigs inhalatively received 200 µg/kg body weight cumyl-5F-P7AICA each. Six hours later, they were euthanized and biopsies of the main tissues and body fluids were taken. Animals were stored in air or water (n=5 each) and samples were repeatedly taken for three days. Quantification of cumyl-5F-P7AICA and its N-pentanoic acid metabolite (NPA) was performed using standard addition or a fully validated method (blood) followed by LC-MS/MS. Time-dependent concentration changes of cumyl-5F-P7AICA were observed in liver, bile fluid and muscle specimens at both conditions. Concentrations of NPA only changed considerably in duodenum content of animals stored in air. Environment-dependent concentrations changes were only observed for cumyl-5F-P7AICA in kidney and the NPA metabolite in duodenum content. Overall, cumyl-5F-P7AICA and its metabolite seem to be quite stable in PM specimens. Hence, also central blood might be analyzed, if no peripheral blood is available.

The Degradation of Absorbable Surgical Threads in Body Fluids: Insights from Infrared Spectroscopy Studies.

This study investigates the degradation of six different types of absorbable surgical threads commonly used in clinical practice, focusing on their response to exposure to physiological fluids. The threads were subjected to hydrolytic and enzymatic degradation in physiological saline, bile, and pancreatic juice. Our findings demonstrate that bile and pancreatic juice, particularly when contaminated with bacterial strains such as Escherichia coli, Klebsiella spp., and Enterococcus faecalis, significantly accelerate the degradation process. Using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and tensile strength testing, we observed distinct differences in the chemical structure and mechanical integrity of the sutures. Principal component analysis (PCA) of the FTIR spectra revealed that PDS threads exhibited the highest resistance to degradation, maintaining their mechanical properties for a longer duration compared with Monocryl and Vicryl. These results highlight the critical role of thread selection in gastrointestinal surgeries, where prolonged exposure to bile and pancreatic juice can compromise the suture integrity and lead to postoperative complications. The insights gained from this study will contribute to improving the selection and application of absorbable threads in clinical settings.

Detection of H1N1 Influenza Virus in the Bile of a Severe Influenza Mouse Model.

AIMS: Influenza virus infection may lead to fatal complications including multi-organ failure and sepsis. The influenza virus was detected in various extra-pulmonary organs in autopsy studies during the 2009 pandemic. However, limited research has been conducted on the presence of viral particle or viral components in the peripheral blood. METHODS AND RESULTS: We established a mouse model for severe H1N1 influenza. The bile and blood samples were collected over time and inoculated into embryonated chicken eggs. We detected live influenza virus in bile and blood samples in early infection. Immunofluorescence showed influenza viral components in the liver tissue. No live virus was isolated in the bile in mice intragastrically administered with influenza virus, indicating that the virus was spread from the blood stream. Targeted metabolomics analysis of bile acid and liver tissues showed that a secondary bile acid (3-dehydrocholic acid) was decreased after influenza H1N1 infection. Genes related with fatty acid metabolism and bile secretion pathways were down-regulated in liver after influenza virus infection. CONCLUSION: Our study indicated that influenza virus viremia is present in severe influenza, and that the liver is a target organ for influenza viral sepsis.

Endothelial force sensing signals to parenchymal cells to regulate bile and plasma lipids.

How cardiovascular activity interacts with lipid homeostasis is incompletely understood. We postulated a role for blood flow acting at endothelium in lipid regulatory organs. Transcriptome analysis was performed on livers from mice engineered for deletion of the flow-sensing PIEZO1 channel in endothelium. This revealed unique up-regulation of Cyp7a1, which encodes the rate-limiting enzyme for bile synthesis from cholesterol in hepatocytes. Consistent with this effect were increased gallbladder and plasma bile acids and lowered hepatic and plasma cholesterol. Elevated portal fluid flow acting via endothelial PIEZO1 and genetically enhanced PIEZO1 conversely suppressed Cyp7a1. Activation of hepatic endothelial PIEZO1 channels promoted phosphorylation of nitric oxide synthase 3, and portal flow-mediated suppression of Cyp7a1 depended on nitric oxide synthesis, suggesting endothelium-to-hepatocyte coupling via nitric oxide. PIEZO1 variants in people were associated with hepatobiliary disease and dyslipidemia. The data suggest an endothelial force sensing mechanism that controls lipid regulation in parenchymal cells to modulate whole-body lipid homeostasis.

Integration of bile proteomics and metabolomics analyses reveals novel insights into different types of gallstones in a high-altitude area.

BACKGROUND: To explore the pathogenesis of different subtypes of gallstones in high-altitude populations from a molecular perspective. METHODS: We collected bile samples from 20 cholesterol gallstone disease (CGD) patients and 20 pigment gallstone disease (PGD) patients. Proteomics analysis was performed by LC/MS DIA, while metabolomics analysis was performed by UPLC- Q-TOF/MS. RESULTS: We identified 154 up-regulated and 196 down-regulated differentially expressed proteins, which were significantly enriched in neurodegenerative diseases, energy metabolism, amino acid metabolism etc. In metabolomics analysis, 20 up-regulated and 63 down-regulated differentially expressed metabolites were identified, and they were significantly enriched in vitamin B6 metabolism. Three pathways of integrated proteomics and metabolomics were significantly enriched: porphyrin and chlorophyll metabolism, riboflavin metabolism and aminoacyl-tRNA biosynthesis. Remarkably, 7 differentially expressed proteins and metabolites showed excellent predictive performance and were selected as potential biomarkers. CONCLUSION: The findings of our metabolomics and proteomics analyses help to elucidate the underlying mechanisms of gallstone formation in high-altitude populations.

Bile from the hemojuvelin-deficient mouse model of iron excess is enriched in iron and ferritin.

Iron is an essential nutrient but is toxic in excess. Iron deficiency is the most prevalent nutritional deficiency and typically linked to inadequate intake. Iron excess is also common and usually due to genetic defects that perturb expression of hepcidin, a hormone that inhibits dietary iron absorption. Our understanding of iron absorption far exceeds that of iron excretion, which is believed to contribute minimally to iron homeostasis. Prior to the discovery of hepcidin, multiple studies showed that excess iron undergoes biliary excretion. We recently reported that wild-type mice raised on an iron-rich diet have increased bile levels of iron and ferritin, a multi-subunit iron storage protein. Given that genetic defects leading to excessive iron absorption are much more common causes of iron excess than dietary loading, we set out to determine if an inherited form of iron excess known as hereditary hemochromatosis also results in bile iron loading. We employed mice deficient in hemojuvelin, a protein essential for hepcidin expression. Mutant mice developed bile iron and ferritin excess. While lysosomal exocytosis has been implicated in ferritin export into bile, knockdown of Tfeb, a regulator of lysosomal biogenesis and function, did not impact bile iron or ferritin levels. Bile proteomes differed between female and male mice for wild-type and hemojuvelin-deficient mice, suggesting sex and iron excess impact bile protein content. Overall, our findings support the notion that excess iron undergoes biliary excretion in genetically determined iron excess.

Implementing Massive Parallel Sequencing into Biliary Samples Obtained through Endoscopic Retrograde Cholangiopancreatography for Diagnosing Malignant Bile Duct Strictures.

Despite advancements in radiologic, laboratory, and pathological evaluations, differentiating between benign and malignant bile duct strictures remains a diagnostic challenge. Recent developments in massive parallel sequencing (MPS) have introduced new opportunities for early cancer detection and management, but these techniques have not yet been rigorously applied to biliary samples. We prospectively evaluated the Oncomine Comprehensive Assay (OCA) and the Oncomine Pan-Cancer Cell-Free Assay (OPCCFA) using biliary brush cytology and bile fluid obtained via endoscopic retrograde cholangiopancreatography from patients with bile duct strictures. The diagnostic performance of MPS testing was assessed and compared to the pathological findings of biliary brush cytology and primary tissue. Mutations in TP53, BRAF, CTNNB1, SMAD4, and K-/N-RAS identified in biliary brush cytology samples were also detected in the corresponding bile fluid samples from patients with extrahepatic cholangiocarcinoma. These mutations were also identified in the bile fluid samples, but with variant allele frequencies lower than those in the corresponding biliary brush cytology samples. In control patients diagnosed with gallstones, neither the biliary brush cytology samples nor the bile fluid samples showed any pathogenic mutations classified as tier 1 or 2. Our study represents a prospective investigation into the role of MPS-based molecular testing in evaluating bile duct strictures. MPS-based molecular testing shows promise in identifying actionable genomic alterations, potentially enabling the stratification of patients for targeted chemotherapeutic treatments. Future research should focus on integrating OCA and OPCCFA testing, as well as similar MPS-based assays, into existing surveillance and management protocols for patients with bile duct strictures.

Identification of whole-genome mutations and structural variations of bile cell-free DNA in cholangiocarcinoma.

Bile cell-free DNA (cfDNA) has been reported as a promising liquid biopsy tool for cholangiocarcinoma (CCA), however, the whole-genome mutation landscape and structural variants (SVs) of bile cfDNA remains unknown. Here we performed whole-genome sequencing on bile cfDNA and analyzed the correlation between mutation characteristics of bile cfDNA and clinical prognosis. TP53 and KRAS were the most frequently mutated genes, and the RTK/RAS, homologous recombination (HR), and HIPPO were top three pathways containing most gene mutations. Ten overlapping putative driver genes were found in bile cfDNA and tumor tissue. SVs such as chromothripsis and kataegis were identified. Moreover, the hazard ratio of HR pathway mutations were 15.77 (95% CI: 1.571-158.4), patients with HR pathway mutations in bile cfDNA exhibited poorer overall survival (P = 0.0049). Our study suggests that bile cfDNA contains genome mutations and SVs, and HR pathway mutations in bile cfDNA can predict poor outcomes of CCA patients.

Comparative Analysis of Digestion Methods for Bile Proteomics: The Key to Unlocking Biliary Biomarker Potential.

BACKGROUND: Bile's potential to reflect the health of the biliary system has led to increased attention, with proteomic analysis offering deeper understanding of biliary diseases and potential biomarkers. With the emergence of normothermic machine perfusion (NMP), bile can be easily collected and analyzed. However, the composition of bile can make the application of proteomics challenging. This study systematically evaluated various trypsin digestion methods to optimize proteomics of bile from human NMP livers. METHODS: Bile was collected from 12 human donor livers that were accepted for transplantation after the NMP viability assessment. We performed tryptic digestion using six different methods: in-gel, in-solution, S-Trap, SMART, EasyPep, and filter-aided sample purification, with or without additional precipitation before digestion. Proteins were analyzed using untargeted proteomics. Methods were assessed for total protein IDs, variation, and protein characteristics to determine the most optimal method. RESULTS: Methods involving precipitation surpassed crude methods in protein identifications (4500 vs 3815) except for in-gel digestion. Filtered data (40%) resulted in 3192 versus 2469 for precipitated and crude methods, respectively. We found minimal differences in mass, cellular components, or hydrophobicity of proteins between methods. Intermethod variability was notably diverse, with in-gel, in-solution, and EasyPep outperforming others. Age-related biological comparisons revealed upregulation of metabolic-related processes in younger donors and immune response and cell cycle-related processes in older donors. CONCLUSIONS: Variability between methods emphasizes the importance of cross-validation across multiple analytical approaches to ensure robust analysis. We recommend the in-gel crude method for its simplicity and efficiency, avoiding additional precipitation steps. Sample processing speed, cost, cleanliness, and reproducibility should be considered when a digestion method is selected for bile proteomics.

Polysaccharides from bile Arisaema exert an antipyretic effect on yeast-induced fever rats through regulating gut microbiota and metabolic profiling.

In our previous study, bile Arisaema was elucidated to have a significant anti-febrile effect, but the pharmacodynamic material basis of this effect remains uncertain. Herein, we found that the soluble polysaccharide fraction from bile Arisaema presents a remarkable antipyretic effect through balancing the gut microbiota and regulating metabolic profiling. Bile Arisaema polysaccharide (BAP) was characterized for its monosaccharide composition with arabinose, galactose, glucose, mannose and xylose (0.028:0.072:0.821:0.05:0.029, molar ratios) and amino acid composition with arginine, threonine, alanine, glycine, serine, proline and tyrosine (109.33, 135.78, 7.22, 8.86, 21.07, 4.96, 12.31 µg/mg). A total of 50 peptides were identified from BAP using Ltq-Orbitrap MS/MS. The oral administration of 100 mg/kg BAP significantly increased the antipyretic effect in yeast-induced fever rats by comparing the rectal temperature. Mechanistically, the inflammation and disorders of neurotransmitters caused by fever were improved by treatment with BAP. The western blotting results suggested that BAP could suppress fever-induced inflammation by down-regulating the NF-κB/TLR4/MyD88 signaling pathway. We also demonstrated that BAP affects lipid metabolism, amino acid metabolism and carbohydrate metabolism and balances the gut microbiota. In summary, the present study provides a crucial foundation for determining polysaccharide activity in bile Arisaema and further investigating the underlying mechanism of action.

Development of an integrated strategy for comprehensive characterization of Sinomenii Caulis extract and metabolites in rats based on UPLC/Q-TOF-MS.

Sinomenii Caulis (SC), a commonly used traditional Chinese medicine for its therapeutic effects on rheumatoid arthritis, contains rich chemical components. At present, most studies mainly focus on sinomenine, with little research on other alkaloids. In this study, a comprehensive profile of compounds in SC extract, and biological samples of rats (including bile, urine, feces, and plasma) after oral administration of SC extract was conducted via ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF-MS). The fragmentation patterns and potential biotransformation pathways of six main types of alkaloids in SC were summarized, and the corresponding characteristic product ions, relative ion intensity, and neutral losses were obtained to achieve rapid classification and identification of complex components of SC from in vitro to in vivo. As a result, a total of 114 alkaloid compounds were identified, including 12 benzyl alkaloids, 4 isoquinolone alkaloids, 32 aporphine alkaloids, 28 protoberberine alkaloids, 34 morphinan alkaloids and 4 organic amine alkaloids. After administration of SC extract to rats, a total of 324 prototypes and metabolites were identified from rat plasma, urine, feces and bile, including 81 aporphines, 95 protoberberines, 117 morphinans and 31 benzylisoquinolines. The main types of metabolites were demethylation, hydrogenation, dehydrogenation, aldehydation, oxidation, methylation, sulfate esterification, glucuronidation, glucose conjugation, glycine conjugation, acetylation, and dihydroxylation. In summary, this integrated strategy provides an additional approach for the incomplete identification caused by compound diversity and low abundance, laying the foundation for the discovery of new bioactive compounds of SC against rheumatoid arthritis.

Morphological changes in the biliary mucosa in pediatric patients with congenital biliary dilatation are more influenced by the duration of amylase exposure than by amylase levels in the gallbladder.

PURPOSE: We investigated the relationship between bile amylase (AMY) levels and biliary epithelial changes in pancreaticobiliary maljunction (PBM), a congenital anomaly characterized by pancreaticobiliary reflux due to duct fusion outside the duodenal wall. METHODS: We enrolled 43 children with congenital biliary dilatation (CBD) of Todani types Ia, Ic, and IVa who underwent surgery at the Hokkaido Medical Center for Child Health and Rehabilitation between November 2007 and June 2023. We defined total AMY exposure in bile as bile AMY levels multiplied by the patient's age (months), representing amount of estimated AMY exposure until surgery. We retrospectively investigated the relationships between bile AMY levels and clinicopathological findings. RESULTS: All patients exhibited hyperplasia in the gallbladder and bile duct epithelium, with dysplasia observed in 13 cases, but no carcinoma. Exposure to bile AMY ≥ 662,400 IU/L × months was an independent risk factor for dysplasia. CONCLUSION: The amount of estimated AMY exposure in bile rather than AMY levels in the bile is an independent risk factor for dysplasia in the biliary mucosa.

Effect of Acupoint Catgut Embedding at Yanglingquan (GB34) on the Bile Metabolism of Patients with Choledocholithiasis after Surgery.

Importance: Choledocholithiasis, or bile duct gallstones, is effectively treated with surgery, which does not prevent relapse. A common adjuvant therapy is the stimulation of the Yanglingquan point (GB34). Acupoint catgut embedding (ACE), an acupoint stimulation therapy, may be a better treatment for choledocholithiasis. Objectives: To investigate the effect of ACE in stimulating GB34 on bile metabolism and its possible mechanism via metabonomics. Methods: In this study, we used ultrahigh performance liquid chromatographyquadrupole time-of-flight mass spectrometry (UHPLC-MS/MS) to analyze the changes in bile metabolites, metabolic pathways, and liver function indicators in 16 patients with choledocholithiasis before and after ACE stimulation. Results: We identified 10 metabolites that exhibited significant differences in the bile before and after ACE, six of which significantly increased and four that significantly decreased. Moreover, six liver function indicators showed a downward trend. We identified related metabolic pathways as glycerophospholipid metabolism, steroid biosynthesis, and the citrate cycle (TCA cycle). Conclusions and Relevance: This study shows that ACE stimulation of GB34 can effectively help treat choledocholithiasis, which may be clinically applicable to ACE.

Does a postmortem redistribution affect the concentrations of the 7 azaindole-derived synthetic cannabinoid 5F-MDMB-P7AICA in tissues and body fluids following pulmonary administration to pigs?

Many fatal intoxications have been reported in connection with the consumption of newer, highly potent synthetic cannabinoids. Yet, a possible postmortem redistribution (PMR) might complicate reliable interpretation of analytical results. Thus, it is necessary to investigate the PMR-potential of new synthetic cannabinoids. The pig model has already proven to be suitable for this purpose. Hence, the aim of this study was to study the PMR of the synthetic cannabinoid 5F-MDMB-P7AICA and its main metabolite 5F-MDMB-P7AICA-dimethylbutanoic acid (DBA). 5F-MDMB-P7AICA (200 µg/kg body weight) was administered by inhalation to anesthetized and ventilated pigs. At the end of the experiment, the animals were euthanized and stored at room temperature for 3 days. Tissue and body fluid samples were taken daily. Specimens were analyzed after solid phase extraction using a standard addition method and LC-MS/MS, blood was quantified after protein precipitation using a validated method. In perimortem samples, 5F-MDMB-P7AICA was found mainly in adipose tissue, bile fluid, and duodenum contents. Small amounts of 5F-MDMB-P7AICA were found in blood, muscle, brain, liver, and lung. High concentrations of DBA were found primarily in bile fluid, duodenum contents, urine, and kidney/perirenal fat tissue. In the remaining tissues, rather low amounts could be found. In comparison to older synthetic cannabinoids, PMR of 5F-MDMB-P7AICA was less pronounced. Concentrations in blood also appear to remain relatively stable at a low level postmortem. Muscle, kidney, fat, and duodenum content are suitable alternative matrices for the detection of 5F-MDMB-P7AICA and DBA, if blood specimens are not available. In conclusion, concentrations of 5F-MDMB-P7AICA and its main metabolite DBA are not relevantly affected by PMR.

Antimicrobial glycoprotein 2 (GP2) in gallstones, bile fluid and peribiliary glands of patients with primary sclerosing cholangitis.

BACKGROUND: Glycoprotein-2 (GP2) IgA is a predictor of disease severity in primary sclerosing cholangitis (PSC). We examined GP2's occurrence in the biliary tract, the site of inflammation. METHODS: GP2 was analyzed using ELISA, immunoblotting, mass spectrometry, and immunohistochemistry. The samples included: 20 bile and 30 serum samples from PSC patients, 23 bile and 11 serum samples from patients with gallstone disease (GD), 15 bile samples from healthy individuals undergoing liver-donation surgery (HILD), 20 extracts of gallstones (GE) obtained during cholecystectomy, and 101 blood-donor sera. RESULTS: Biliary GP2 concentrations were significantly higher in patients with PSC and GD than in HILD (p < 0.0001). Serum GP2 levels were similar in PSC and GD patients, and controls, but lower than in bile (p < 0.0001). GP2 was detected in all 20 GEs. Mass spectrometry identified GP2 in the bile of 2 randomly selected GD and 2 PSC patients, and in none of 2 HILD samples. GP2 was found in peribiliary glands in 8 out of 12 PSC patients, showing morphological changes in acinar cells, but not in GD-gallbladders. CONCLUSIONS: GP2 is present in bile of PSC and GD patients. It is synthesized in the peribiliary glands of PSC patients, supporting a pathogenic role for biliary GP2 in PSC.

Cell wall polysaccharide enhances Lacticaseibacillus paracasei strain Shirota growth in milk and contributes to acid and bile tolerance.

LCPS-1, a cell wall polysaccharide (CWPS), is bound to the cell wall of the probiotic Lacticaseibacillus paracasei (formerly known as Lactobacillus casei) strain Shirota (LcS). Generally, the role of CWPS in the viability and survivability of bacteria is yet to be fully understood. This study aimed to elucidate the role of LCPS-1 in the viability and survivability of LcS. A mutant strain completely lacking LCPS-1 was constructed and evaluated for growth in bovine and soy milk and susceptibility to acid and bile. The growth of the mutant in bovine and soy milk temporarily stalled after the late logarithmic phase while wild-type LcS continued growing, resulting in a significantly lower number of viable cells for the mutant strain (p < 0.01). Significantly higher cell death relative to that of the wild-type strain was observed for the mutant strain following acid treatment at pH 3.0 (p < 0.01), with 60 and 92 % survival, respectively. The absence of LCPS-1 also reduced the survival rate of LcS cells from 3.3 to 0.8 % following 0.2 % bile treatment. The survival rate of the mutant after consecutive treatment with acid and bile was 19 %, while 73 % of the wild-type LcS survived. These results indicate that LCPS-1 leads to higher LcS growth in milk and improves tolerance to acid and bile. This study reveals the contribution of probiotic bacterial CWPS to acidic and gastrointestinal stress tolerance. Based on these findings, characterizing and modifying CWPS in probiotic strains could enhance manufacturing yields and improve gastrointestinal stress tolerance after consumption by hosts, ultimately advancing the development of more effective probiotics.

Coordinated action of a gut-liver pathway drives alcohol detoxification and consumption.

Alcohol use disorder (AUD) affects millions of people worldwide, causing extensive morbidity and mortality with limited pharmacological treatments. The liver is considered as the principal site for the detoxification of ethanol metabolite, acetaldehyde (AcH), by aldehyde dehydrogenase 2 (ALDH2) and as a target for AUD treatment, however, our recent data indicate that the liver only plays a partial role in clearing systemic AcH. Here we show that a liver-gut axis, rather than liver alone, synergistically drives systemic AcH clearance and voluntary alcohol drinking. Mechanistically, we find that after ethanol intake, a substantial proportion of AcH generated in the liver is excreted via the bile into the gastrointestinal tract where AcH is further metabolized by gut ALDH2. Modulating bile flow significantly affects serum AcH level and drinking behaviour. Thus, combined targeting of liver and gut ALDH2, and manipulation of bile flow and secretion are potential therapeutic strategies to treat AUD.

Assessing the degree of hepatic ischemia-reperfusion injury using physiologically based pharmacokinetic modeling of sodium fluorescein disposition in ex vivo machine-perfused livers.

Ischemia-reperfusion injury (IRI) is an intrinsic risk associated with liver transplantation. Ex vivo hepatic machine perfusion (MP) is an emerging organ preservation technique that can mitigate IRI, especially in livers subjected to prolonged warm ischemia time (WIT). However, a method to quantify the biological response to WIT during MP has not been established. Previous studies used physiologically based pharmacokinetic (PBPK) modeling to demonstrate that a decrease in hepatic transport and biliary excretion of the tracer molecule sodium fluorescein (SF) could correlate with increasing WIT in situ. Furthermore, these studies proposed intracellular sequestration of the hepatocyte canalicular membrane transporter multidrug resistance-associated protein 2 (MRP2) leading to decreased MRP2 activity (maximal transport velocity; Vmax) as the potential mechanism for decreased biliary SF excretion. We adapted an extant PBPK model to account for ex vivo hepatic MP and fit a six-parameter version of this model to control time-course measurements of SF in MP perfusate and bile. We then identified parameters whose values were likely insensitive to changes in WIT and fixed them to generate a reduced model with only three unknown parameters. Finally, we fit the reduced model to each individual biological replicate SF time course with differing WIT, found the mean estimated value for each parameter, and compared them using a one-way ANOVA. We demonstrated that there was a significant decrease in the estimated value of Vmax for MRP2 at the 30-min WIT. These studies provide the foundation for future studies investigating real-time assessment of liver viability during ex vivo MP.NEW & NOTEWORTHY We developed a computational model of sodium fluorescein (SF) biliary excretion in ex vivo machine perfusion and used this model to assess changes in model parameters associated with the activity of MRP2, a hepatocyte membrane transporter, in response to increasing warm ischemia time. We found a significant decrease in the parameter value describing MRP2 activity, consistent with a role of decreased MRP2 function in ischemia-reperfusion injury leading to decreased secretion of SF into bile.

Metabolite identification and excretion of pinocembrin-7-O-ß-D-glucoside in rats by UHPLC/MS.

Pinocembrin-7-O-ß-D-glucoside (PCBG) isolated from Penthorum chinense Pursh was proven to display a wide range of pharmacological effects including hepatoprotection, anti-hepatoma and antifungal activities, etc. The research aims to qualitatively analyze the metabolites of PCBG in rat plasma, urine, bile and feces, and further perform the excretion study of PCBG and its major metabolite pinocembrin (PCB). Fifteen rats were divided into three groups (n=5 for each group) for blood, bile, urine and feces collection, respectively. After PCBG suspension was intragastrically administered to rats at 50 mg/kg, biological samples were collected and processed. The metabolites in each matrix were detected by UHPLC-Q-Exactive-MS/MS. A total of 111 metabolites were observed in plasma, urine, bile and feces, which include hydroxylated, sulfated and glucuronized metabolites, etc. In addition, an UHPLC-MS/MS method was established and applied for the excretion quantification of PCBG and PCB in rat urine, bile, and feces samples. Studies on excretion have shown that PCBG is mainly excreted through feces. The cumulative excretion rates of PCBG and PCB in rat urine, bile and feces were (4.5±2.4)%, (0.2±0.1)% and (18.4±10.5)%, respectively. After hydrolysis by ß-glucuronidase/sulfatase, the excretion rates of PCB in urine and bile were (5.7±2.8)% and (8.9±4.2)%. This study contributes to preclinical research on PCBG and explains its pharmacological effects.