Citric Acid Cycle Metabolites Predict Infarct Size in Pigs Submitted to Transient Coronary Artery Occlusion and Treated with Succinate Dehydrogenase Inhibitors or Remote Ischemic Perconditioning.

Succinate dehydrogenase (SDH) inhibition with malonate during reperfusion reduced myocardial infarction in animals, whereas its endogenous substrate, succinate, is detected in plasma from STEMI patients. We investigated whether protection by SDH inhibition is additive to that of remote ischemic perconditioning (RIC) in pigs submitted to transient coronary artery occlusion, and whether protective maneuvers influence plasma levels of citric acid cycle metabolites. Forty pigs were submitted to 40 min coronary occlusion and reperfusion, and allocated to four groups (controls, sodium malonate 10 mmol/L, RIC, and malonate + RIC). Plasma was obtained from femoral and great cardiac veins and analyzed by LC-MS/MS. Malonate, RIC, and malonate + RIC reduced infarct size (24.67 ± 5.98, 25.29 ± 3.92 and 29.83 ± 4.62% vs. 46.47 ± 4.49% in controls, p < 0.05), but no additive effects were detected. Enhanced concentrations of succinate, fumarate, malate and citrate were observed in controls during initial reperfusion in the great cardiac vein, and most were reduced by cardioprotective maneuvers. Concentrations of succinate, fumarate, and malate significantly correlated with infarct size. In conclusion, despite the combination of SDH inhibition during reperfusion and RIC did not result in additive protection, plasma concentrations of selected citric acid cycle metabolites are attenuated by protective maneuvers, correlate with irreversible injury, and might become a prognosis tool in STEMI patients.

Measurement of bempedoic acid and its keto metabolite in human plasma and urine using solid phase extraction and electrospray LC-MS/MS.

Bempedoic acid, a new therapeutic for treatment of hypercholesterolemia, inhibits hepatic ATP-citrate lyase in the cholesterol synthesis pathway after its conjugation with coenzyme A. Sensitive and selective methods were required to study the pharmacokinetic behavior of bempedoic acid and its active 8-keto metabolite in clinical studies. A mixed mode anion exchange extraction on 96-well plates was developed to favor high, selective recoveries of these dicarboxylic acids from urine or plasma. Adsorptive losses in urine led to inaccurate measurements unless samples were acidified and diluted with isopropanol prior to any specimen transfers. Tandem mass spectrometry with negative ion electrospray ionization permitted lower limits of measurement of 20 and 10 ng/mL for the drug and metabolite in either matrix. The methods were validated to current regulatory standards and have been the basis for pharmacokinetic measurements in 26 clinical studies involving over 15,000 samples.

The Selective Oral Immunomodulator Vidofludimus in Patients with Active Rheumatoid Arthritis: Safety Results from the COMPONENT Study.

INTRODUCTION: The dihydroorotate dehydrogenase (DHODH) inhibitors leflunomide and teriflunomide are immunomodulatory agents approved to treat rheumatoid arthritis (RA) and multiple sclerosis, respectively, and are actively being investigated as therapeutic agents for other immune-related diseases; however, both structurally related compounds have a number of potentially serious adverse effects. Vidofludimus, a new selective second-generation DHODH inhibitor, is chemically distinct from leflunomide/teriflunomide and appears to exhibit a distinct safety profile. OBJECTIVE: The aim of the COMPONENT study was to assess the efficacy, safety, and pharmacokinetics of vidofludimus in the treatment of patients with active RA on a background therapy of methotrexate. This report focuses solely on the safety results of the COMPONENT trial. METHODS: Patients received once-daily oral vidofludimus (N = 122) or placebo (N = 119) along with their standard of care methotrexate treatment for 13 weeks. Efficacy endpoints were assessed. Safety parameters were monitored throughout treatment and at follow-up. Plasma concentrations of vidofludimus were measured. RESULTS: The primary efficacy endpoint, American College of Rheumatology 20 (ACR20) responder rate at 13 weeks, demonstrated numerical superiority in the treatment group compared with placebo; however, it did not reach statistical significance. Nonetheless, the COMPONENT study yielded important safety and pharmacokinetic data that could provide important information regarding the use of vidofludimus in other clinical trials, not only for RA but also for other autoimmune diseases. A safety profile for vidofludimus similar to placebo was obtained in this RA patient population. This includes similar rates of the adverse events of diarrhea, alopecia, neutropenia, and elevated liver enzymes, all of which are known drug-related adverse events reported for leflunomide and teriflunomide. A potential pharmacokinetic interaction between vidofludimus and methotrexate was observed. CONCLUSIONS: Vidofludimus demonstrated a positive safety profile, making it a promising candidate for the treatment of a variety of immune-related diseases. TRIAL REGISTRATIONS: ClinicalTrials.gov identifier: NCT01010581.

Preclinical disposition of MGS0274 besylate, a prodrug of a potent group II metabotropic glutamate receptor agonist MGS0008 for the treatment of schizophrenia.

MGS0274 besylate is an ester-based lipophilic prodrug of a metabotropic glutamate (mGlu) 2 and mGlu3 receptor agonist MGS0008 and being developed for the treatment of schizophrenia. We investigated the disposition of these compounds in rats and monkeys and in vitro metabolism in humans to evaluate whether MGS0274 besylate could be useful as a prodrug in humans. After the oral administration of MGS0274 besylate to monkeys (2.89 mg/kg), MGS0008 was immediately found in plasma, reached a maximum concentration at 4 hours postdose, and decreased with a terminal half-life of 16.7 hours; MGS0274 was barely detectable. The oral bioavailability as MGS0008 was 83.7%, which was approximately 20-fold greater than that after oral dosing of MGS0008 (3.8%). In rats, MGS0008 penetrated the cerebrospinal fluid and was eliminated slower than from plasma. The in vitro metabolism study indicated that MGS0274 was rapidly hydrolyzed to MGS0008, which was not further metabolized. After the intravenous administration of MGS0008 to rats and monkeys, almost all the dose was excreted unchanged in urine. These results suggested that MGS0274 was, as expected, presystemically hydrolyzed to MGS0008 after gastrointestinal absorption and that MGS0008 was distributed throughout the body without further metabolism and ultimately excreted in urine in the animals. Furthermore, the hydrolytic activity against MGS0274 in the human liver S9 fraction was comparable to that in monkeys, suggesting the possibility of the rapid presystemic hydrolysis of MGS0274 to MGS0008 in humans, as it is in monkeys. Consequently, MGS0274 besylate is expected to function as a preferable prodrug in humans.

Development and validation of a bioanalytical assay based on liquid chromatography-tandem mass spectrometry for measuring biomarkers of exposure of alternative plasticizers in human urine and serum.

Alternative plasticizers (APs) have been increasingly used in the last decade to replace conventional phthalate esters, in particular di(2-ethylhexyl) phthalate (DEHP), due to the toxicity of the latter. However, there is currently very little data about the toxicity of and exposure to APs. No method exists so far for the analysis of multiple exposure biomarkers. The objective of this work consisted in developing a simple bioanalytical procedure for the analysis of multiple exposure biomarkers of APs in human urine and serum. Focus was set on metabolites of di(2-propylheptyl) phthalate (DPrHpP), di(isononyl)cyclohexane-1,2-dicarboxylate (DINCH), di(2-ethylhexyl) terephthalate (DEHTP) and di-2-ethylhexyl adipate (DEHA). A sample preparation protocol was developed and optimized using Oasis HLB solid-phase extraction (SPE) cartridges. Subsequently, an instrumental method based on liquid-chromatography coupled to tandem mass spectrometry (LC-MS/MS) was optimized. Following established guidelines, the sample preparation and instrumental methods were validated in terms of recovery, matrix effects, carry-over, linearity, limits of quantification, within- and between-run precision and trueness. Obtained results were satisfactory for all compounds except for one of the metabolites of DEHA (i.e., mono(2-ethylhexyl) adipate (MEHA)). A pilot biomonitoring study was carried out to assess the method's ability to detect and quantify target analytes in human urine and serum. In urine, most analytes could be detected with frequencies ranging from 8% for mono(2-ethyl-5-hydroxyhexyl) adipate (OH-MEHA) and cyclohexane-1,2-dicarboxylic mono hydroxyisononyl ester (OH-MINCH) to 92% for mono(2-ethyl-5-oxohexyl) adipate (oxo-MEHA), whilst most compounds could not be detected in serum, except for mono(2-ethylhexyl) terephthalate (MEHTP) and mono-(2-propyl-6-hydroxyheptyl) phthalate (OH-MPrHpP) which were detected in all samples. The obtained results show that the developed method can be used to simultaneously analyse multiple exposure biomarkers to APs in human urine and serum.

Pregn-5-en-3ß-ol and androst-5-en-3ß-ol dicarboxylic acid esters as potential therapeutics for NMDA hypofunction: In vitro safety assessment and plasma stability.

Neurosteroids are endogenous steroidal compounds that can modulate neuronal receptors. N-Methyl-D-aspartate receptors (NMDARs) are glutamate-gated, calcium-permeable ion channels that are of particular interest, as they participate in synaptic transmission and are implicated in various processes, such as learning, memory, or long-term neuronal potentiation. Positive allosteric modulators that increase the activity of NMDARs may provide a therapeutic aid for patients suffering from neuropsychiatric disorders where NMDAR hypofunction is thought to be involved, such as intellectual disability, autism spectrum disorder, or schizophrenia. We recently described a new class of pregn-5-ene and androst-5-ene 3ß-dicarboxylic acid hemiesters (2-24) as potent positive modulators of NMDARs. Considering the recommended guidelines for the early stage development of new, potent compounds, we conducted an in vitro safety assessment and plasma stability screening to evaluate their druglikeness. First, compounds were screened for their hepatotoxicity and mitochondrial toxicity in a HepG2 cell line. Second, toxicity in primary rat postnatal neurons was estimated. Next, the ability of compounds 2-24 to cross a Caco-2 monolayer was also studied. Finally, rat and human plasma stability screening revealed an unforeseen high stability of the C-3 hemiester moiety. In summary, by using potency/efficacy towards NMDARs data along with toxicity profile, Caco-2 permeability and plasma stability, compounds 14 and 15 were selected for further in vivo animal studies.

In Schizophrenia, Deficits in Natural IgM Isotype Antibodies Including those Directed to Malondialdehyde and Azelaic Acid Strongly Predict Negative Symptoms, Neurocognitive Impairments, and the Deficit Syndrome.

Schizophrenia is characterized by an interrelated activation of the immune-inflammatory response system (IRS) and the compensatory immune-regulatory system (CIRS), which downregulates the IRS. Deficit schizophrenia is characterized by a deficit in IgM-mediated autoimmune responses to tryptophan catabolites. The presence and correlates of IgM isotype antibodies to oxidative-specific epitopes (OSEs), nitroso (NO), and nitro (NO2) adducts in schizophrenia remain unknown. This study measured IgM antibodies to malondialdehyde (MDA), azelaic acid, phosphatidylinositol, oleic acid, NO-tryptophan, NO-albumin, NO-cysteinyl, and NO2-tyrosine in a sample of 80 schizophrenia patients, divided into those with and those without deficit schizophrenia, and 38 healthy controls. Deficit schizophrenia was characterized by significantly lower IgM antibody levels to all OSEs as compared with non-deficit schizophrenia and controls. Lowered IgM antibodies to MDA coupled with increased IgM levels to NO-cysteinyl and NO2-tyrosine strongly predict deficit schizophrenia versus non-deficit schizophrenia with an area under the ROC curve of 0.913. A large part of the variance (21.2-42.2%) in the negative symptoms of schizophrenia and excitation is explained by IgM antibody titers to MDA (inversely) and NO-cysteinyl and/or NO2-tyrosine (both positively). Lower IgM antibodies to MDA are significantly associated with impairments in episodic memory including direct and delayed recall. These findings further indicate that deficit schizophrenia is a distinct phenotype of schizophrenia, which is characterized by lower natural IgM antibody levels to OSEs and relative increments in nitrosylation and nitration of proteins. It is concluded that deficits in natural IgM attenuate CIRS functions and that this impairment may drive negative symptoms and impairments in episodic memory and thus deficit schizophrenia.

In Schizophrenia, Increased Plasma IgM/IgA Responses to Gut Commensal Bacteria Are Associated with Negative Symptoms, Neurocognitive Impairments, and the Deficit Phenotype.

Increased gut permeability (leaky gut) with increased translocation of Gram-negative bacteria plays a role in the gut-brain axis through effects on systemic immune-inflammatory processes. Deficit schizophrenia is characterized by an immune-inflammatory response combined with a deficit in natural IgM antibodies to oxidative-specific epitopes (OSEs), which are a first-line defense against bacterial infections. This study measured plasma IgA/IgM responses to 5 Gram-negative bacteria in association with IgM responses to malondialdehyde (MDA) and azelaic acid in 80 schizophrenia patients (40 with the deficit syndrome and 40 without) and in 38 healthy controls. Deficit schizophrenia was characterized by significantly increased IgA responses to Hafnei alvei, Pseudomonas aeruginosa, Morganella morganii, and Klebsiella pneumoniae as compared with non-deficit schizophrenia. The presence of deficit schizophrenia was highly predicted by increased IgA responses to Pseudomonas putida and IgM responses to all five Gram-negative bacteria and lowered natural IgM to MDA and azelaic acid with a bootstrap area under the receiver operating characteristic curve of 0.960 (2000 random curves). A large proportion of the variance (41.5%) in the negative subscale score of the Positive and Negative Syndrome Scale was explained by the regression on IgA responses to K. pneumoniae and IgM responses to the five enterobacteria coupled with lowered IgM antibodies to azelaic acid. There were significant associations between IgA levels to Gram-negative bacteria and Mini-Mental State Examination, Boston naming test, Verbal Fluency, and Word List Memory test scores. These findings provide further evidence that deficit schizophrenia is a distinct phenotype of schizophrenia, which is characterized by an increased impact of Gram-negative commensal bacteria coupled with a deficit in natural IgM, pointing to aberrations in B1 cells. It is concluded that increased bacterial translocation and deficits in the compensatory immune-regulatory system (CIRS) may drive negative symptoms and neurocognitive impairments, which are hallmarks of deficit schizophrenia.

The metabolic analysis of psoriasis identifies the associated metabolites while providing computational models for the monitoring of the disease.

The majority of studies on psoriasis have focused on explaining the genetic background and its associations with the immune system's response. The aim of this study was to identify the low-molecular weight compounds contributing to the metabolomic profile of psoriasis and to provide computational models that help with the classification and monitoring of the severity of the disease. We compared the results from targeted and untargeted analyses of patients' serums with plaque psoriasis to controls. The main differences were found in the concentrations of acylcarnitines, phosphatidylcholines, amino acids, urea, phytol, and 1,11-undecanedicarboxylic acid. The data from the targeted analysis were used to build classification models for psoriasis. The results from this study provide an overview of the metabolomic serum profile of psoriasis along with promising statistical models for the monitoring of the disease.

Metabolomic and Genome-wide Association Studies Reveal Potential Endogenous Biomarkers for OATP1B1.

Transporter-mediated drug-drug interactions (DDIs) are a major cause of drug toxicities. Using published genome-wide association studies (GWAS) of the human metabolome, we identified 20 metabolites associated with genetic variants in organic anion transporter, OATP1B1 (P < 5 × 10-8 ). Of these, 12 metabolites were significantly higher in plasma samples from volunteers dosed with the OATP1B1 inhibitor, cyclosporine (CSA) vs. placebo (q-value < 0.2). Conjugated bile acids and fatty acid dicarboxylates were among the metabolites discovered using both GWAS and CSA administration. In vitro studies confirmed tetradecanedioate (TDA) and hexadecanedioate (HDA) were novel substrates of OATP1B1 as well as OAT1 and OAT3. This study highlights the use of multiple datasets for the discovery of endogenous metabolites that represent potential in vivo biomarkers for transporter-mediated DDIs. Future studies are needed to determine whether these metabolites can serve as qualified biomarkers for organic anion transporters. Quantitative relationships between metabolite levels and modulation of transporters should be established.

Kinetic and molecular orbital analyses of dicarboxylic acylcarnitine methylesterification show that derivatization may affect the screening of newborns by tandem mass spectrometry.

Newborns are routinely screened for organic acidemias by acylcarnitine analysis. We previously reported the partial catalytic methylesterification of dicarboxylic acylcarnitines by benzenesulfonic acid moiety in the solid extraction cartridge during extraction from serum. Since the diagnosis of organic acidemias by tandem mass spectrometry is affected by the higher molecular weight of these derivatized acylcarnitines, we investigated the methylesterification conditions. The kinetic constants for the methylesterification of carboxyl groups on the acyl and carnitine sides of carnitine were 2.5 and 0.24h(-1), respectively. The physical basis underlying this difference in methylesterification rates was clarified theoretically, illustrating that methylesterification during extraction proceeds easily and must be prevented.

Development of a multi-compartment pharmacokinetic model to characterize the exposure to Hexamoll® DINCH®.

We developed and calibrated a multi compartment pharmacokinetic (PK) model to predict urinary concentrations after oral exposure of four specific DINCH metabolites: MINCH, OH-MINCH, cx-MINCH, and oxo-MINCH. This descriptive model has 4 compartments: a "stomach" (SC) compartment, a "holding" (HC) compartment, a "blood" (BC) compartment and a "bladder" (BLC) compartment. DINCH is assumed to first deposit into the SC, with transfer split between the HC and the BC. Unmetabolized DINCH from the HC then transfers to the BC. The DINCH metabolism is assumed to occur in the BC before excretion via the BLC. At each urination event, all the metabolite mass in the BLC is excreted. The model was calibrated using published urine metabolite data from 3 different male volunteers, each orally dosed with 50mg DINCH. Full urine voids were taken for 48 h after dosage. The predicted values showed a good agreement with the observed urinary DINCH metabolite concentrations, with a Spearman correlation coefficient exceeding 0.7 for all oxidized metabolites. We showed the importance of a holding reservoir. Without it, a good agreement could not be found. We applied the model to a set of 24-h general population samples measured for DINCH metabolites. The model was unable to duplicate the ratio of metabolites seen in the 24-h samples. Two possibilities were offered to explain the difference: the exposure pattern in the general population did not match the oral exposure in the dosing experiments, or the long-term toxicokinetics of DINCH was not captured in the 48-h controlled dosing experiments.

Integrated metabolomic profiling of hepatocellular carcinoma in hepatitis C cirrhosis through GC/MS and UPLC/MS-MS.

BACKGROUND & AIMS: The metabolic pathway disturbances associated with hepatocellular carcinoma (HCC) remain unsatisfactorily characterized. Determination of the metabolic alterations associated with the presence of HCC can improve our understanding of the pathophysiology of this cancer and may provide opportunities for improved disease monitoring of patients at risk for HCC development. To characterize the global metabolic alterations associated with HCC arising from hepatitis C (HCV)-associated cirrhosis using an integrated non-targeted metabolomics methodology employing both gas chromatography/mass spectrometry (GC/MS) and ultrahigh-performance liquid chromatography/electrospray ionization tandem mass spectrometry (UPLC/MS-MS). METHODS: The global serum metabolomes of 30 HCC patients, 27 hepatitis C cirrhosis disease controls and 30 healthy volunteers were characterized using a metabolomics approach that combined two metabolomics platforms, GC/MS and UPLC/MS-MS. Random forest, multivariate statistics and receiver operator characteristic analysis were performed to identify the most significantly altered metabolites in HCC patients vs. HCV-cirrhosis controls and which therefore exhibited a close association with the presence of HCC. RESULTS: Elevated 12-hydroxyeicosatetraenoic acid (12-HETE), 15-HETE, sphingosine, γ-glutamyl oxidative stress-associated metabolites, xanthine, amino acids serine, glycine and aspartate, and acylcarnitines were strongly associated with the presence of HCC. Elevations in bile acids and dicarboxylic acids were highly correlated with cirrhosis. CONCLUSIONS: Integrated metabolomic profiling through GC/MS and UPLC/MS-MS identified global metabolic disturbances in HCC and HCV-cirrhosis. Aberrant amino acid biosynthesis, cell turnover regulation, reactive oxygen species neutralization and eicosanoid pathways may be hallmarks of HCC. Aberrant dicarboxylic acid metabolism, enhanced bile acid metabolism and elevations in fibrinogen cleavage peptides may be signatures of cirrhosis.

Serum metabolomics indicate altered cellular energy metabolism in children with cystic fibrosis.

BACKGROUND: Cystic fibrosis (CF) is a multi-system disease affecting multiple organs and cells besides the respiratory system. Metabolomic profiling allows simultaneous detection of biochemicals originating from cells, organs, or exogenous origin that may be valuable for monitoring of disease severity or in diagnosis. AIM: We hypothesized that metabolomics using serum from children would differentiate CF from non-CF lung disease subjects and would provide insight into metabolism in CF. METHODS: Serum collected from children with CF (n = 31) and 31 age and gender matched children with other lung diseases was used for metabolomic profiling by gas- and liquid-chromatography. Relative concentration of metabolites was compared between the groups using partial least square discriminant analyses (PLS-DA) and linear modeling. RESULTS: A clear separation of the two groups was seen in PLS-DA. Linear model found that among the 459 detected metabolites 92 differed between CF and non-CF. These included known biochemicals in lipid metabolism, oxidants, and markers consistent with abnormalities in bile acid processing. Bacterial metabolites were identified and differed between the groups indicating intestinal dysbiosis in CF. As a novel finding several pathways were markedly different in CF, which jointly point towards decreased activity in the ß-oxidation of fatty acids. These pathways include low ketone bodies, low medium chain carnitines, elevated di-carboxylic acids and decreased 2-hydroxybutyrate from amino acid metabolism in CF compared to non-CF. CONCLUSION: Serum metabolomics discriminated CF from non-CF and show altered cellular energy metabolism in CF potentially reflecting mitochondrial dysfunction. Future studies are indicated to examine their relation to the underlying CF defect and their use as biomarkers for disease severity or for cystic fibrosis transmembrane regulator (CFTR) function in an era of CFTR modifying drugs.

Phase I clinical trial of the novel platin complex dicycloplatin: clinical and pharmacokinetic results.

UNLABELLED: TRANSLATIONAL RELEVANCE: Dicycloplatin (DCP) is a novel super molecule composed of carboplatin (CBP) and 1,1-cyclobutane dicarboxylate (CBDCA) joined by a strong hydrogen bond. The solubility and stability of platinum complexes have a direct bearing on their activity, toxicity and pharmacokinetics. Preclinical studies have shown that DCP overcomes the problem of CBP instability in aqueous solution and maintains anticancer effects. Clinical evaluation in a Phase I dose-escalation study in patients with tumors showed that DCP was tolerated at doses ranging from 100 to 550 mg/m(2) and had potential efficacy in Chinese cancer patients. DCP showed favourable bioavailability and stability in vivo, and the recommended Phase II dosage for DCP-containing chemotherapy is 450 mg/m(2). DCP is currently being investigated as a monotherapy in several cancer types, such as prostatic carcinoma, and in combination with paclitaxel in a Phase II non-lung cancer study. PURPOSE: Dicycloplatin (DCP) is a novel supramolecule composed of carboplatin (CBP) and 1,1-cyclobutane dicarboxylate (CBDCA) joined by a strong hydrogen bond. DCP is stable in aqueous solution unlike CBP alone. The purpose of this study was to assess the maximally tolerated dose, safety, and pharmacokinetics of DCP in Chinese cancer patients. EXPERIMENTAL DESIGN: 29 patients were included in this study. DCP was administered by intravenous infusion over 1 hour once every 21 days. The dose of DCP was escalated from 50 mg/m(2) to 650 mg/m(2) using a modified Fibonacci scheme. Pharmacokinetic analysis was performed in 26 patients to determine the total and ultrafiltered platinum concentrations in plasma. RESULTS: 29 and 20 patients were evaluated for toxicities and response, respectively. The primary adverse effects were nausea/vomiting (58.6%), thrombocytopenia (24.1%), neutropenia (17.2%), anemia (20.7%), fatigue (10.3%), anorexia (10.3%), liver enzyme elevation (10.3%) and alopecia (3.5%). There was no significant toxicity with doses up to 350 mg/m(2). At higher doses, a variety of dose-limiting toxicities (DLTs) were observed, including Grade 3/4 anemia, Grade 3/4 thrombocytopenia, and Grade 3/4 emesis under antiemetic treatment. The maximum tolerated dose of DCP was 550 mg/m(2). Two partial responses occurred in patients with non-cell lung cancer who had received cisplatin- or carboplatin-based chemotherapy. Plasma decay of total and free platinum concentrations was best fitted by using a twocompartment analysis. The terminal plasma half-life of total platinum after DCP administration ranged from 41.86 to 77.20 hours without significant dose dependency. However, the terminal plasma half-life of free platinum concentrations ranged from 42.34 to 61.07 hours. CONCLUSIONS: DCP displayed a favorable safety profile at doses between 50 mg/m(2) and 550 mg/m(2), and first efficacy signals were observed. DLTs were thrombocytopenia, anemia and emesis. The recommended starting dose for a subsequent Phase II study is 450 mg/m(2) once every 3 weeks.

Metabolomics identifies an inflammatory cascade involved in dioxin- and diet-induced steatohepatitis.

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is among the most potent environmentally toxic compounds. Serum metabolomics identified azelaic acid monoesters as significantly increased metabolites after TCDD treatment, due to downregulation of hepatic carboxylesterase 3 (CES3, also known as triglyceride hydrolase) expression in an arylhydrocarbon receptor (AhR)-dependent manner in mice. The decreased CES3 expression was accomplished by TCDD-stimulated TGFß-SMAD3 and IL6-STAT3 signaling, but not by direct AhR signaling. Methionine- and choline-deficient (MCD) diet-treated mice also showed enhanced serum azelaic acid monoester levels after attenuation of hepatic CES3 expression, while db/db mice did not, thus suggesting an association with steatohepatitis. Forced expression of CES3 reversed serum azelaic acid monoester/azelaic acid ratios and hepatic TGFß mRNA levels in TCDD- and MCD diet-treated mice and ameliorated steatohepatitis induced by MCD diet. These results support the view that azelaic acid monoesters are possible indicators of TCDD exposure and steatohepatitis and suggest a link between CES3, TGFß, and steatohepatitis.

Identification of potential biomarkers of exposure to di(isononyl)cyclohexane-1,2-dicarboxylate (DINCH), an alternative for phthalate plasticizers.

Di(isononyl)cyclohexane-1,2-dicarboxylate (DINCH) is used as an alternative for some phthalate plasticizers. In rats, DINCH mostly eliminates in feces as cyclohexane-1,2-dicarboxylic acid (CHDA), mono isononyl ester (MINCH) or in urine as CHDA. However, CHDA is not a specific biomarker of DINCH and measuring MINCH in feces is impractical. To identify additional potential biomarkers, we administered DINCH (500 mg/kg body weight) in a single subcutaneous (SC) or oral dose to four adult female Sprague-Dawley rats. We collected 24-h urine samples before dosing (to be used as controls) and 24-h and 48-h after dosing, and serum at necropsy after 48 h. We positively identified and accurately quantified CHDA and cyclohexane-1,2-dicarboxylic [corrected] acid, mono hydroxyisononyl ester (MHNCH) using authentic standards. Moreover, we tentatively identified MINCH and 12 oxidative metabolites, including 4 cyclohexane ring oxidation products, based on their mass spectrometric-fragmentation patterns. CHDA and MHNCH levels were higher in the urine collected 24 h after oral than SC administration. By contrast, 48-h after dosing, CHDA urinary levels were similar regardless of the exposure route. We detected all but two of the urine metabolites also in serum. Levels of CHDA and MHNCH in serum were lower than in the two post-dose urine collections. Our results suggest that several urinary oxidative metabolites, specifically CHDA, mono oxoisononyl ester and MHNCH may be used as specific biomarkers of DINCH exposure in humans.

Metabolomics reveals reduction of metabolic oxidation in women with polycystic ovary syndrome after pioglitazone-flutamide-metformin polytherapy.

Polycystic ovary syndrome (PCOS) is a variable disorder characterized by a broad spectrum of anomalies, including hyperandrogenemia, insulin resistance, dyslipidemia, body adiposity, low-grade inflammation and increased cardiovascular disease risks. Recently, a new polytherapy consisting of low-dose flutamide, metformin and pioglitazone in combination with an estro-progestagen resulted in the regulation of endocrine clinical markers in young and non-obese PCOS women. However, the metabolic processes involved in this phenotypic amelioration remain unidentified. In this work, we used NMR and MS-based untargeted metabolomics to study serum samples of young non-obese PCOS women prior to and at the end of a 30 months polytherapy receiving low-dose flutamide, metformin and pioglitazone in combination with an estro-progestagen. Our results reveal that the treatment decreased the levels of oxidized LDL particles in serum, as well as downstream metabolic oxidation products of LDL particles such as 9- and 13-HODE, azelaic acid and glutaric acid. In contrast, the radiuses of small dense LDL and large HDL particles were substantially increased after the treatment. Clinical and endocrine-metabolic markers were also monitored, showing that the level of HDL cholesterol was increased after the treatment, whereas the level of androgens and the carotid intima-media thickness were reduced. Significantly, the abundance of azelaic acid and the carotid intima-media thickness resulted in a high degree of correlation. Altogether, our results reveal that this new polytherapy markedly reverts the oxidant status of untreated PCOS women, and potentially improves the pro-atherosclerosis condition in these patients.

Metabolite profiling identifies markers of uremia.

ESRD is a state of small-molecule disarray. We applied liquid chromatography/tandem mass spectrometry-based metabolite profiling to survey>350 small molecules in 44 fasting subjects with ESRD, before and after hemodialysis, and in 10 age-matched, at-risk fasting control subjects. At baseline, increased levels of polar analytes and decreased levels of lipid analytes characterized uremic plasma. In addition to confirming the elevation of numerous previously identified uremic toxins, we identified several additional markers of ESRD, including dicarboxylic acids (adipate, malonate, methylmalonate, and maleate), biogenic amines, nucleotide derivatives, phenols, and sphingomyelins. The pattern of lipids was notable for a universal decrease in lower-molecular-weight triacylglycerols, and an increase in several intermediate-molecular-weight triacylglycerols in ESRD compared with controls; standard measurement of total triglycerides obscured this heterogeneity. These observations suggest disturbed triglyceride catabolism and/or beta-oxidation in ESRD. As expected, the hemodialysis procedure was associated with significant decreases in most polar analytes. Unexpected increases in several metabolites, however, indicated activation of a broad catabolic program, including glycolysis, lipolysis, ketosis, and nucleotide breakdown. In summary, this study demonstrates the application of metabolite profiling to identify markers of ESRD, provide perspective on uremic dyslipidemia, and broaden our understanding of the biochemical effects of hemodialysis.

Implication of agathic acid from Utah juniper bark as an abortifacient compound in cattle.

Freshly ground Utah juniper [Juniperus osteosperma (Torr.) Little] bark was given via gavage at a dosage of 2.3 kg per cow twice daily to three pregnant cows starting on day 255 of gestation. All three cows aborted the calves after 4, 5 and 6 days of treatment. A fourth cow was dosed with Utah juniper needles and this cow calved early on day 268 of gestation with complications consistent with pine needle abortion. Chemical analysis of Juniperus osteosperma bark identified the major diterpene acid as the labdane acid known as agathic acid. Agathic acid was measured in the bark at a concentration of 1.5% (dry weight basis). Analysis of sera samples obtained from treated cows found detectable quantities of agathic acid, dihydroagathic acid and tetrahydroagathic acid, which are known serum metabolites of the abortifacient compound isocupressic acid. Based on the high incidence of induced abortion and detection of known metabolites in affected animals, the labdane acid known as agathic acid is considered to be an abortifacient compound in late-term pregnant cattle.