Hepatic Drug Metabolism Research Articles

Liquid Biopsy Enables Quantification of the Abundance and Interindividual Variability of Hepatic Enzymes and Transporters.

Variability in individual capacity for hepatic elimination of therapeutic drugs is well recognized and is associated with variable expression and activity of liver enzymes and transporters. Although genotyping offers some degree of stratification, there is often large variability within the same genotype. Direct measurement of protein expression is impractical due to limited access to tissue biopsies. Hence, determination of variability in hepatic drug metabolism and disposition using liquid biopsy (blood samples) is an attractive proposition during drug development and in clinical practice. This study used a multi‐“omic” strategy to establish a liquid biopsy technology intended to assess hepatic capacity for metabolism and disposition in individual patients. Plasma exosomal analysis (n = 29) revealed expression of 533 pharmacologically relevant genes at the RNA level, with 147 genes showing evidence of expression at the protein level in matching liver tissue. Correction of exosomal RNA expression using a novel shedding factor improved correlation against liver protein expression for 97 liver‐enriched genes. Strong correlation was demonstrated for 12 key drug‐metabolizing enzymes and 4 drug transporters. The developed test allowed reliable patient stratification, and in silico trials demonstrated utility in adjusting drug dose to achieve similar drug exposure between patients with variable hepatic elimination. Accordingly, this approach can be applied in characterization of volunteers prior to enrollment in clinical trials and for patient stratification in clinical practice to achieve more precise individual dosing.

Adenosine deaminases acting on RNA modulate the expression of the human pregnane X receptor

The pregnane X receptor (PXR) is one of the major transcription factors that regulate the expression of different drug-metabolizing enzymes and transporters. Adenosine-to-inosine RNA editing, the most frequent nucleotide conversion on RNA, which is catalyzed by adenosine deaminase acting on RNA (ADAR) enzymes, may modulate gene expression and function. Here, we investigated the potential regulation of human PXR expression by adenosine-to-inosine RNA editing. Knockdown of ADAR1 increased PXR mRNA level, and the knockdown of ADAR1 or ADAR2 significantly increased PXR protein level in HepaRG cells. In HepG2 cells, the knockdown of ADAR1 or ADAR2 significantly increased PXR mRNA and protein levels. The increase in the PXR protein by ADAR1 knockdown resulted in increased cytochrome P450 3A4 (CYP3A4) transactivity and CYP3A4 and UDP-glucuronosyltransferase 1A1 (UGT1A1) expression. A reporter assay revealed that the 3′-untranslated region (UTR) of PXR mRNA, especially from +3371 to +3440, is responsible for the ADAR-mediated post-transcriptional control of PXR expression, despite the lack of RNA edited sites in this region. Collectively, we found that PXR is negatively regulated by ADAR1 via an indirect mechanism, which facilitates the degradation of PXR mRNA. We could demonstrate that ADAR1 can cause interindividual variability in hepatic drug metabolism potencies.

Evaluation of hepatic drug-metabolism for glioblastoma using liver-brain chip.

Glioma is one of the most aggressive and highly fatal diseases with an extremely poor prognosis. Considering the poor clinical response to therapy in glioma, it is urgent to establish an in vitro model to facilitate the screening and assessment of anti-brain-tumor drugs. The blood-brain barrier (BBB), as well as liver metabolism plays an important role in determining the pharmacological activity of many anti-brain-tumor drugs. In this work, we designed a multi-interface liver-brain chip integrating co-culture system to assess hepatic metabolism dependent cytotoxicity of anti-brain-tumor drug in vitro. This microdevice composed of three microchannels which were separated by porous membrane and collagen. HepG2 and U87 cells were cultured in separated channels as mimics of liver and glioblastoma. Brain microvascular endothelial cells (BMECS) and cerebral astrocytes were co-cultured on collagen to mimic the brain microvascular endothelial barrier. Three common anti-tumor drugs, paclitaxel (PTX), capecitabine (CAP) and temozolomide (TMZ), were evaluated on this chip. In integrated liver-brain chip, liver enhanced the cytotoxicity of CAP on U87 cells by 30%, but having no significant effect on TMZ. The BBB decreased the cytotoxicity of PTX by 20%, while no significant effects were observed on TMZ and CAP, indicating the importance of liver metabolism and blood-brain barrier on the evaluation of anti-brain-tumor drugs. This work provides a biomimetic liver-brain model to mimic the physiological and pharmacological processes in vitro and presents a simple platform for long-term cell co-culture, drug delivery and metabolism, and real-time analysis of drug effects on brain cancer.

Development of a method to determine cytochrome P450 1A2, 2C9, 2D6 and 3A4 activity sheep hepatic microsomes

IntroductionEx vivo studies of human fetal hepatic drug metabolism are uncommon as it requires access to functional liver tissue and therefore raises practical and ethical concerns. Large animal models provide an alternative opportunity to study changes in cytochrome P450 (CYP) activity in the mother and fetus during pregnancy. We aimed to develop methods to determine the activity of CYP1A2, CYP2C9, CYP2D6 and CYP3A4 in sheep hepatic microsomes. MethodsWe identified optimal conditions to determine the activity of CYP1A2 (using the probe drug phenacetin), CYP2C9 (diclofenac), CYP2D6 (dextromethorphan) and CYP3A4 (midazolam) by varying techniques for microsome extraction, probe drug concentration, incubation time and microsome concentration. The specificity of each probe drug was assessed by determining the rate of metabolism when specific CYP enzyme inhibitors were included in the reaction. ResultsThe optimum incubation time and probe drug concentration was six hours with 5 μM phenacetin (CYP1A2), four hours with 10 μM diclofenac (CYP2C9), 30 min with 1 μM of midazolam (CYP3A4) and 10 min with 1 μM dextromethorphan (CYP2D6). For both CYP2D6 and CYP3A4 reactions required 20 μg of microsomal protein, whereas for CYP1A2 and CYP2C9, reactions required 40 μg of microsomal protein. Metabolism of phenacetin, dextromethorphan and midazolam was reduced by specific enzyme inhibitors, but the specific CYP2C9 inhibitor sulfaphenazole did not substantially inhibit diclofenac metabolism. DiscussionThis study identifies the optimal conditions for determining CYP activity in maternal sheep hepatic microsomes. In doing so, we have developed a standardised protocol for assessment of microsomal activity of CYP3A4, CYP1A2 and CYP2D6, but we were unable to optimise conditions for assessment of CYP2C9. This approach can be applied to investigate the impact of pregnancy complications on maternal and fetal hepatic drug metabolism.

Preventive Effect of a Polyphenol-Rich Extract from Geranium sanguineum L. on Hepatic Drug Metabolism in Influenza Infected Mice

The decreased hepatic drug metabolism (predominately first phase) is one of the essential reasons for numerous side effects and for increased drug toxicity during influenza virus infection (IVI). The present study aims to investigate some mechanisms of the preventive effect of a standardized polyphenol complex from the medicinal plant Geranium sanguineum L. (PPhC) (10 mg/kg nasally). A verified experimental model of IVI A/Aichi/2/68 (H3N2) (4.5 lg LD50) in male ICR (Institute of Cancer Research, USA) mice was used. Changes in hepatic monooxygenase activities as well as nicotinamide adenine dinucleotide phosphate (NADPH)-cytochrome C reductase activity and cytochtome P450 content were studied on days 2, 6, 9, 21 of the infection together with thiobarbituric acid reactive substances in the liver supernatant. Our data clearly demonstrates that IVI affects all components of the electronic chain of cytochrome P-450. N-demethylases and hydroxylases as well as the activity of cytochrome C reductase and cytochtome P-450 content were decreased in the course of the virus infection. This implies that free radicals play an important role not only in the pathogenesis of IVI, but also in the modulation of the hepatic monooxygenase activity. This is also consistent with the established polyphenol complex PPhC from the medicinal plant Geranium sanguineum L. preventive effect against increased thiobarbituric acid reactive substances (TBARS)-levels. PPhC restored most of the monooxygenase activities that were inhibited in IVI animals, even over the control levels, probably via multiple mechanisms that may entail antioxidant activity and selective antiviral and protein-binding effects. In contrast to infected animals, in healthy mice, PPhC showed moderate reversible inhibitory effect on hepatic monooxygenase activities.

Carbamazepine and Hyperpigmentation in a Young Woman: A Case Report

Carbamazepine (CBZ) is an effective and first-line treatment for trigeminal neuralgia and has a key place in the management of epilepsy and bipolar disorder. There is the possibility ofclinically important drug interactions because CBZ may induce the hepatic metabolism of other drugs or, conversely, other drugs may induce or inhibit CBZ metabolism. The drug isa member of a big group of antiepileptic drugs that are widely used to prevent and control seizures. It has been associated with several cutaneous side effects. In this case, we reporta young woman who presented with dyspnea, weight loss, pancytopenia, abdominal pain, oligomenorrhea, and two weeks history of hyperpigmented lesions over her face, neck, andtwo hands. She had a history of seizures and did well on carbamazepine for the last 7 months. Carbamazepine was discontinued and she was treated with local emollients. The lesions werepartially improved in 2 weeks.

LC-MS/MS Estimation of the Anti-Cancer Agent Tandutinib Levels in Human Liver Microsomes: Metabolic Stability Evaluation Assay.

PurposeTandutinib (MLN518 or CT 53518) (TND) is a novel, oral, small-molecule inhibitor of type III receptor tyrosine kinases utilized for the treatment of acute myeloid leukemia (AML).Materials and MethodsIn silico prediction of hepatic drug metabolism for TND was determined using the StarDrop® WhichP450™ module to confirm its metabolic liability. Second, an efficient and accurate LC-MS/MS method was established for TND quantification to evaluate metabolic stability. TND and entrectinib (ENC) (internal standard; IS) were resolved using an isocratic elution system with a reversed stationary phase (C8 column).ResultsThe established LC-MS/MS method exhibited linearity (5–500 ng/mL) with r2 ≥0.9999 in the human liver microsomes matrix. The method sensitivity was indicated by the limit of quantification (3.8 ng/mL), and reproducibility was revealed by inter- and intraday precision and accuracy (below 10.5%). TND metabolic stability estimation was calculated using intrinsic clearance (22.03 µL/min/mg) and in vitro half-life (29.0 min) values.ConclusionTND exhibited a moderate extraction ratio indicative of good bioavailability. According to the literature, the approach developed in the present study is the first established LC-MS/MS method for assessing TND metabolic stability.

High‐Precision 3D Bio‐Dot Printing to Improve Paracrine Interaction between Multiple Types of Cell Spheroids

AbstractCell–cell interaction accounts for one of the most influential factors affecting the viability and functionality of cell‐based tissue models. In this respect, various methods capable of producing micro‐patterns with cell spheroids are introduced to simultaneously improve contact‐dependent and ‐independent cell‐cell interactions. However, no method has yet been designed to effectively generate precise 3D patterns with multiple spheroid types. In this study, a new high‐precision and convenient 3D spheroid printing technology is developed, designated as 3D bio‐dot printing. This new technique is designed to produce cell‐laden, non‐adhesive micro‐pores within 3D structures to allow cell spheroids to be induced at printed sites. Experimental results show that various cell types, including hepatocytes, pancreatic β‐cells, and breast cancer cells, can be employed for the in situ formation of cell spheroids, and 3D freeform structures with multiple spheroid types can be printed. Moreover, this novel technology can also be used for performing 3D invasion assays. More importantly, it ensures that the precise control of spheroid size and position is achieved at micrometer scale. Finally, the usefulness of this novel technology is demonstrated by producing multicellular micro‐patterns with primary hepatocyte spheroids and endothelial cells, that exhibit significantly improved long‐term hepatic function and drug metabolism.

Predictability of human pharmacokinetics of drugs that undergo hepatic organic anion transporting polypeptide (OATP)-mediated transport using single-species allometric scaling in chimeric mice with humanized liver: integration with hepatic drug metabolism

We previously reported a prediction method for human pharmacokinetics (PK) using single species allometric scaling (SSS) and the complex Dedrick plot in chimeric mice with humanized liver to predict the total clearance (CLt), distribution volumes in steady state (Vdss) and plasma concentration-time profiles of several drugs metabolized by cytochrome P450 (P450) and non-P450 enzymes. In the present study, we examined eight compounds (bosentan, cerivastatin, fluvastatin, pitavastatin, pravastatin, repaglinide, rosuvastatin, valsartan) as typical organic anion transporting polypeptide (OATP) substrates and six compounds metabolized by P450 and non-P450 enzymes to evaluate the predictability of CLt, Vdss and plasma concentration-time profiles after intravenous administration to chimeric mice. The predicted CLt and Vdss of drugs that undergo OATP-mediated uptake and P450/non-P450-mediated metabolism reflected the observed data from humans within a threefold error range. We also examined the possibility of predicting plasma concentration-time profiles of drugs that undergo OATP-mediated uptake using the complex Dedrick plot in chimeric mice. Most profiles could be superimposed with observed profiles from humans within a two- to threefold error range. PK prediction using SSS and the complex Dedrick plot in chimeric mice can be useful for evaluating drugs that undergo both OATP-mediated uptake and P450/non-P450-mediated metabolism.

Induction of in vitro Metabolic Zonation in Primary Hepatocytes Requires Both Near-Physiological Oxygen Concentration and Flux.

Pre-clinical drug screening is an important step in assessing the metabolic effects and hepatic toxicity of new pharmaceutical compounds. However, due to the complexity of the liver microarchitecture, simplified in vitro models do not adequately reflect in vivo situations. Especially spatial heterogeneity, known as metabolic zonation, is often lost due to limitations introduced by typical culture conditions. By culturing primary rat hepatocytes in varied ambient oxygen levels on either gas-permeable or non-permeable culture plates, we highlight the importance of biomimetic oxygen supply for the targeted induction of zonation-like phenotypes. Resulting cellular profiles illustrate the effect of pericellular oxygen concentration and consumption rates on hepatic functionality in terms of zone-specific metabolism and β-catenin signaling. We show that modulation of ambient oxygen tension can partially induce metabolic zonation in vitro when considering high supply rates, leading to in vivo-like drug metabolism. However, when oxygen supply is limited, similar modulation instead triggers an ischemic reprogramming, resembling metabolic profiles of hepatocellular carcinoma and increasing susceptibility toward drug-induced injury. Application of this knowledge will allow for the development of more accurate drug screening models to better identify adverse effects in hepatic drug metabolism.

Physicochemical stability of compounded midazolam capsules over a one-year storage period

Abstract Objectives In patients suffering from chronic liver disease, the hepatic metabolism of drugs is perturbed and the metabolic capacity is difficult to assess. Midazolam could be used as a phenotypical probe to predict the metabolic capacity of CYP3A to adjust dosages of drug substrates of this cytochrome. In this context, a prospective clinical trial is going to be conducted in our institution and a hospital preparation of midazolam capsules suitable for the clinical trial was developed. The objective of the present work was to assess the physicochemical stability of the formulation over 12 months to set shelf life. Methods Three batches of 1 mg capsules were prepared using midazolam hydrochloride and microcrystalline cellulose as a diluent. The capsules were stored at ambient temperature and protected from light. To measure the evolution of the capsules content, a stability-indicating high-performance liquid chromatography (HPLC) method was developed with ultraviolet (UV) detection at 254 nm. Data were confirmed using a liquid chromatography-tandem mass spectrometry (LC-MS/MS) analytical method. Results After one year, midazolam hydrochloride content remained higher than 95% of the initial concentration in capsules. Conclusions The results show that 1 mg midazolam capsules are stable for 12 months at room temperature and under dark conditions.

High fat diet significantly changed the global gene expression profile involved in hepatic drug metabolism and pharmacokinetic system in mice

BackgroundHigh fat diet impact transcription of hepatic genes responsible for drug metabolism and pharmacokinetics. Until now, researches just focused on a couple specific genes without a global profile showing. Age-dependent manner was also not noted well. This study aims to investigate the high fat diet effect on transcriptome of drug metabolism and pharmacokinetic system in mouse livers and show the age-dependent evidence.MethodsC57BL/6 male mice were used in this experiment. High fat diet was used to treat mice for 16 and 38 weeks. Serum total cholesterol, low density lipoprotein cholesterol, aspartate transaminase, and alanine transaminaselevels were measured. Meanwhile, Histology, RNA-Seq, RT-PCR analysis and fourteen major hepatic bile acids quantification were performed for the liver tissues. Data was mined at levels of genes, drug metabolism and pharmacokinetic sysem, and genome wide.ResultsTreatment with high fat diet for 38 weeks significantly increased levels of serum lipids as well as aspartate transaminase, and alanine transaminase. Meanwhile, lipid accumulation in livers was observed. At week 38 of the experiment, the profile of 612 genes involved in drug metabolism and pharmacokinetics was significantly changed, indicated by a heatmap visulization and a principal component analysis. In total 210 genes were significantly regulated. Cyp3a11, Cyp4a10, and Cyp4a14 were down-regulated by 10–35 folds, while these three genes also were highly expressed in the liver. High fat diet regulated 11% of genome-wide gene while 30% of genes involved in the hepatic drug metabolism and pharmacokinetic system. Genes, including Adh4, Aldh1b1, Cyp3a11, Cyp4a10, Cyp8b1, Fmo2, Gsta3, Nat8f1, Slc22a7, Slco1a4, Sult5a1, and Ugt1a9, were regulated by high fat diet as an aging-dependent manner. Bile acids homeostasis, in which many genes related to metabolism and transportation were enriched, was also changed by high fat diet with an aging-dependet manner. Expression of genes in drug metabolism and disposition system significantly correlated to serum lipid profiles, and frequently correlated with each other.ConclusionsHigh fat diet changed the global transcription profile of hepatic drug metabolism and pharmacokinetic system with a age-dependent manner.

Methamphetamine administration increases hepatic CYP1A2 but not CYP3Aactivity in female guinea pigs.

Methamphetamine use has increased over the past decade and the first use of methamphetamine is most often when women are of reproductive age. Methamphetamine accumulates in the liver; however, little is known about the effect of methamphetamine use on hepatic drug metabolism. Methamphetamine was administered on 3 occassions to female Dunkin Hartley guinea pigs of reproductive age, mimicking recreational drug use. Low doses of test drugs caffeine and midazolam were administered after the third dose of methamphetamine to assess the functional activity of cytochrome P450 1A2 and 3A, respectively. Real-time quantitative polymerase chain reaction was used to quantify the mRNA expression of factors involved in glucocorticoid signalling, inflammation, oxidative stress and drug transporters. This study showed that methamphetamine administration decreased hepatic CYP1A2 mRNA expression, but increased CYP1A2 enzyme activity. Methamphetamine had no effect on CYP3A enzyme activity. In addition, we found that methamphetamine may also result in changes in glucocorticoid bioavailability, as we found a decrease in 11β-hydroxysteroid dehydrogenase 1 mRNA expression, which converts inactive cortisone into active cortisol. This study has shown that methamphetamine administration has the potential to alter drug metabolism via the CYP1A2 metabolic pathway in female guinea pigs. This may have clinical implications for drug dosing in female methamphetamine users of reproductive age.

Use of Specific Inhibitory Antibodies for P450 Reaction Phenotyping of Investigational Drugs

Identifying the CYP450 enzymes underlying metabolism of investigational drugs (i.e., P450 reaction phenotyping; PRP) is critical to the development of effective therapeutics. Information gained from such studies can: a) provide insight into structural modifications of test drugs in order to improve metabolic stability and; b) specify an estimate of drug‐drug interaction potential as well as that of interindividual and species differences in oxidative metabolism. CYP450 chemical inhibitors (e.g., a‐naphthoflavone and sulfaphenazole) are often used in reaction phenotyping studies but the outcome is sometimes equivocal due to the non‐specific effects of these chemical agents plus their capacity to undergo P450‐dependent catabolism. In contrast, inhibitory P450 antibodies offer high specificity and irreversibility, and may thus represent a superior approach for characterizing individual P450 enzyme involvement in drug metabolism. We recently developed a compilation of highly‐specific polyclonal and monoclonal antibodies to the CYP450s comprising the major oxidative drug‐metabolizing enzymes in human liver, including CYP1A2, CYP2C8, CYP2C9, CYP2C19, CYP2D6 and CYP3A4 (aka CYP ImmunoInhibit antibodies). As shown here, each of these antibodies proved capable of eliciting > 80% inhibition of probe drug metabolism by the cognate P450 antigens in human liver microsomes (HLMx), while giving insignificant effects on different CYP450s (Figure 1). The inhibition observed with each of the six CYP450 antibodies was not only highly‐specific but was also dose‐dependent, with maximal inhibition (80–90%) achieved at IgG:microsomal protein ratios ranging from 0.1 mg/mg to 3 mg/mg (Figure 2). Control (pre‐immune) antibodies had no effect on substrate metabolism. Such results show that inhibitory antibodies coupled with HLMx represent an alternative and powerful approach to chemical inhibitors for evaluating involvement of specific P450 enzymes in the hepatic metabolism of investigational drugs. Interestingly, studies ongoing with CYP ImmunoInhibit antibodies and MetMax™ cryopreserved human hepatocytes, which are liver cells that have been permeabilized and cryopreserved, have given analogous results to those achieved with HLMx. The utilization of inhibitory antibodies with HLMx represents an accurate model for PRP of new therapeutics due to the specificity of these immunoreagents, and the irreversible nature of the inhibition achieved, an important benefit when working with metabolically‐stable test agents.Specific Inhibition of Microsomal Drug Metabolism by CYP ImmunoInhibit AntibodiesFigure 1Dose‐Response Inhibition of Microsomal Drug Metabolism by CYP ImmunoInhibit AntibodiesFigure 2

DNA methylation and histone acetylation changes to cytochrome P450 2E1 regulation in normal aging and impact on rates of drug metabolism in the liver.

Aging is associated with reduced liver function that may increase the risk for adverse drug reactions in older adults. We hypothesized that age-related changes to epigenetic regulation of genes involved in drug metabolism may contribute to this effect. We reviewed published epigenome-wide studies of human blood and identified the cytochrome P450 2E1 (CYP2E1) gene as a top locus exhibiting epigenetic changes with age. To investigate potential functional changes with age in the liver, the primary organ of drug metabolism, we obtained liver tissue from mice aged 4-32months from the National Institute on Aging. We assayed global DNA methylation (5-methylcytosine, 5mC), hydroxymethylation (5-hydroxymethylcytosine, 5hmC), and locus-specific 5mC and histone acetylation changes around mouse Cyp2e1. The mouse livers exhibit significant global decreases in 5mC and 5hmC with age. Furthermore, 5mC significantly increased with age at two regulatory regions of Cyp2e1 in tandem with decreases in its gene and protein expressions. H3K9ac levels also changed with age at both regulatory regions of Cyp2e1 investigated, while H3K27ac did not. To test if these epigenetic changes are associated with varying rates of drug metabolism, we assayed clearance of the CYP2E1-specific probe drug chlorzoxazone in microsome extracts from the same livers. CYP2E1 intrinsic clearance is associated with DNA methylation and H3K9ac levels at the Cyp2e1 locus but not with chronological age. This suggests that age-related epigenetic changes may influence rates of hepatic drug metabolism. In the future, epigenetic biomarkers could prove useful to guide dosing regimens in older adults.

P112 - Primary human hepatocyte 3D spheroids for studying hepatic function and drug metabolism

P112 - Primary human hepatocyte 3D spheroids for studying hepatic function and drug metabolism

Dosing of Antimycotic Treatment in Sepsis–Induced Liver Dysfunction by Functional Liver Testing with LiMAx®

Background Sepsis-treatment is one of the major challenges in our time. Especially fungal infections play an important role in patient's morbidity and mortality. In patients with septic shock, liver function is often significantly impaired and therefore also hepatic drug metabolism is altered. Case Presentation We report about a 56-year-old man suffering from invasive fungal infection with multiorgan failure, after complicated medical history due to symptomatic infrarenal aortic aneurysm. On the first postoperative day, a CT scan was undertaken due to massive back pain showing renal infarction on both sides. As qualitative and quantitative renal function was impaired, hemodialysis was started immediately. Subsequently, the patient developed a compartment syndrome of the left leg and underwent fasciotomy. On admission day 7, the patient presented with hematochezia leading to colonoscopy. During this procedure, an ischemic colitis was observed. As conservative treatment failed, the patient underwent Hartmann's procedure due to progredient ischemia followed by a worsening of the clinical status due to sepsis. The patient suffered from an invasive fungal infection with Candida spp. and Aspergillus spp. Systemic antifungal treatment was initiated. Although azoles are considered first-line treatment in these cases we chose the echinocandin caspofungin for its presumed lower impact on liver function compared to azoles like voriconazole or Amphothericin B. However, caspofungin is also metabolised in the liver and can cause hepatotoxic effects. Therefore we measured metabolic liver function capacity using LiMAx®and adapted the patient's dose of caspofungin to the evaluated liver function capacity to achieve an effective and liver-protective level of the active drug. After complicated medical history with 15 weeks of hospital stay, the patient was discharged in general good condition. Conclusions To our knowledge, this is the first report that relates antimycotic drug dosing to a functional liver test. We provide a new approach for sepsis treatment considering liver function capacity to optimize dosage of hepatically metabolised drugs with potential hepatotoxic effects.

A Systematic Review of Drug Metabolism Studies of Plants With Anticancer Properties: Approaches Applied and Limitations.

Hepatic drug metabolism is a key influence on the efficacy and safety of medicines from both chemical and natural product sources. Studies of the metabolism of synthetic compounds, herbal medicines/supplements, and herb-derived bioactive compounds are therefore challenging. The aim of the present review is to provide a summary of the approaches/techniques that are currently being employed to investigate different aspects of the metabolism of herbs and herb-derived compounds (reaction phenotyping, metabolite profiling, metabolic clearance prediction, metabolic/pharmacokinetic drug interactions, and metabolism-related pharmacokinetic studies), including their limitations. A thorough search of the PubMed database was performed using the terms 'Cancer' AND 'Cytochrome P450 (CYP)' OR 'Phase I metabolism' OR 'Phase II metabolism' AND 'Natural product' OR 'Herbal medicine' OR 'Herbal product' OR 'Herb-derived compound.' Most of the studies (84 studies, 83.2%) retrieved during the search investigated metabolic/pharmacokinetic drug interactions. Three (3.0%), 7 (6.9%), 6 (5.9%), and 1 (1.0%) study involved metabolism-related pharmacokinetic studies, reaction phenotyping, metabolite profiling, and prediction of metabolic clearance, respectively. Various studies reported conflicting results, with the results depending on the nature of the herb investigated (extracts or active constituents) and the biochemical tool (subcellular fractions, cells, or recombinant enzymes) and study system (in vitro/in vivo/ex vivo/clinical) applied. Each approach/system has its own advantages and disadvantages. Selecting the most appropriate approaches/systems allows us to extract the most meaningful and clinically relevant information on the metabolic pathways (the metabolites generated and the enzymes involved) and the potential drug interactions of herb-derived compounds for cancer therapy and prevention. Human primary hepatocytes are the best model that can be applied in any metabolic study. Human liver microsomes (HLMs) are a useful biochemical tool for preliminary drug metabolism studies. Recombinant microsomes that express specific enzymes and CYP-isoform-specific monoclonal antibodies are useful tools for enzyme inhibition studies.

Western Diet-Induced Metabolic Alterations Affect Circulating Markers of Liver Function before the Development of Steatosis.

Since nutrition might have a significant impact on liver function, we analyzed the early effect of Western-type diet on hepatic tissue and lipid and drug metabolism in Wistar–Kyoto rats (n = 8); eight rats fed with a standard diet were used as controls. Histological analysis of liver tissue was performed, and plasma biochemical parameters were measured. Plasma concentration of six bile acids was determined by ultra-liquid chromatography-tandem mass spectrometry UHPLC-MS/MS. Hepatic gene expressions of enzymes involved in drug and lipid metabolism were assessed by means of real-time reverse transcription (qRT)-PCR. Liver of rats fed with a Western diet did not show macroscopic histological alterations, but number and diameter of lipid droplets increased, as well as DGAT1, GPAT4, SCD, FASN and SREBP2 expression. Furthermore, Western diet-fed animals showed an increase in the activation of hepatic stellate cells and macrophage number in liver tissue, as well as a significant increase in AST and bilirubin levels (p < 0.01), and in the LDL:HDL cholesterol ratio (p < 0.001). Plasma chenodeoxycholic acid concentration increased significantly, whereas cholic acid decreased (p < 0.05), and cytochrome P450 genes were generally downregulated. Significant changes in hepatic lipid and drug metabolism are early induced by the Western diet, prior to steatosis development. Such changes are associated with a peculiar alteration in circulating bile acids, which could represent an early marker of non-alcoholic fatty liver disease (NAFLD) development.

High-content analysis of constitutive androstane receptor (CAR) translocation identifies mosapride citrate as a CAR agonist that represses gluconeogenesis

The constitutive androstane receptor (CAR) plays an important role in hepatic drug metabolism and detoxification but has recently been projected as a potential drug target for metabolic disorders due to its repression of lipogenesis and gluconeogenesis. Thus, identification of physiologically-relevant CAR modulators has garnered significant interest. Here, we adapted the previously characterized human CAR (hCAR) nuclear translocation assay in human primary hepatocytes (HPH) to a high-content format and screened an FDA-approved drug library containing 978 compounds. Comparison of hCAR nuclear translocation results with the Tox21 hCAR luciferase reporter assay database in 643 shared compounds revealed significant overlap between these two assays, with approximately half of hCAR agonists also mediating nuclear translocation. Further validation of these compounds in HPH and/or using published data from literature demonstrated that hCAR translocation exhibits a higher correlation with the induction of hCAR target genes, such as CYP2B6, than the luciferase assay. In addition, some CAR antagonists which repress CYP2B6 mRNA expression in HPH, such as sorafenib, rimonabant, and CINPA1, were found to translocate hCAR to the nucleus of HPH. Notably, both the translocation assay and the luciferase assay identified mosapride citrate (MOS), a gastroprokinetic agent that is known to reduce fasting blood glucose levels in humans, as a novel hCAR activator. Further studies with MOS in HPH uncovered that MOS can repress the expression of gluconeogenic genes and decrease glucose output from hepatocytes, providing a previously unidentified liver-specific mechanism by which MOS modulates blood glucose levels.