Metabolic profiling analysis of a D-galactosamine/lipopolysaccharide-induced mouse model of fulminant hepatic failure

Astaxanthin Attenuates D-Galactosamine-Induced Pancreatic Injury by Activating Antioxidant Enzymes and Inhibiting VEGF-C Gene Expression

<b>Background and Objective:</b> Astaxanthin (3,3'-dihydroxy-β-β-carotene-4,4'-dione) is a carotenoid, commonly found in marine environments has been reported to possess versatile biological properties including anti-inflammatory and antioxidant. In this study, the pancreatic protective effect of astaxanthin was investigated in D-Galactosamine-induced pancreas injury in rats. <b>Materials and Methods:</b> In this experimental study, MTT assay was used to determine cytotoxic effects of the Astaxanthin on pnc1 cells. A total of 30 adult albino rats divided into 5 groups, six rats in each. Group I was given an equal amount of distilled water, group II was received 400 mg kg<sup>1</sup> b.wt. D-galactosamine on 15th day, groups III-V were treated with astaxanthin (50 and 100 mg kg<sup>1</sup>) and/or silymarin (50 mg kg<sup>1</sup>) for 14 days + 400 mg kg<sup>1</sup> b.wt. D-galactosamine on the 15th day, respectively. <b>Results:</b> IC<sub>50 </sub>of Astaxanthin against the pnc1 cell line was 92.9 μg mL<sup>1</sup>. The daily oral administration of astaxanthin (50 and 100 mg kg<sup>1</sup>) as well as silymarin (50 mg kg<sup>1</sup>) for 14 days to rats treated with D-galactosamine resulted in a significant improvement in plasma AST, ALT, ALP as well as pancreatic TNF-α, IL-1β, IL-10, NO and VEGF-C gene expression. On the other hand, inducible oral administration of astaxanthin increased the activity of pancreatic GSH, SOD, GPx, GR, CAT and the level of TBARs in D-galactosamine-treated pancreatic of rats. Furthermore, Astaxanthin almost normalized these effects in pancreatic tissue histoarchitecture and MRI examination. <b>Conclusion:</b> The obtained results showed that Astaxanthin protected experimental animals against D-galactosamine-induced pancreatic injury through activation of antioxidant enzymes and IL-10 and inhibition of VEGF-C activation.

Hepatotoxicity evaluation of Euphorbia kansui on zebrafish larvae in vivo

BACKGROUND

Euphorbia kansui is effective in treating various diseases, such as ascites and edema, but its liver toxicity is a major obstacle in its wide use in the clinic. However, further investigations have suggested that Euphorbia kansui can cause liver injury.

HYPOTHESIS

The study aims to investigate the effect of Euphorbia kansui exposure on zebrafish, and explain the underlying toxicity mechanisms from a comprehensive perspective.

STUDY DESIGN

The 4dpf zebrafish larvae were exposed to Euphorbia kansui at a sub-lethal concentration.

METHODS

We evaluated the effect of Euphorbia kansui on the ultrastructure and function of the liver, apoptosis of liver cells by PCR and western blot, and metabolic profile by GC-MS based on sub-lethal concentrations.

RESULTS

Our results suggested Euphorbia kansui could lead to liver injury and significant alteration of the metabolomics of the zebrafish larvae in sub-lethal concentration conditions. It could also induce alterations in liver microstructure, hepatic function, gene expression and protein associated with the apoptosis process, as well as endogenous metabolism. KEGG pathway analysis identified some biological processes on the basis of different metabolisms and their associated processes especially for amino acid metabolism.

CONCLUSION

The results bring us closer to an in-depth understanding of the toxic effects of Euphorbia kansui on zebrafish liver, which will be significantly helpful in effectively guiding safer clinical application of this herb in the clinic. Furthermore, our results also showed the zebrafish model is reliable for evaluation of Euphorbia kansui extract hepatotoxicity and as a methodological reference for the evaluation of Traditional Chinese Medicine with underlying liver toxicity.

Depletion of RIPK1 in hepatocytes exacerbates liver damage in fulminant viral hepatitis

The protein kinase RIPK1 plays a crucial role at the crossroad of stress-induced signaling pathways that affects cell’s decision to live or die. The present study aimed to define the role of RIPK1 in hepatocytes during fulminant viral hepatitis, a worldwide syndrome mainly observed in hepatitis B virus (HBV) infected patients. Mice deficient for RIPK1, specifically in liver parenchymal cells (Ripk1^LPC-KO) and their wild-type littermates (Ripk1^fl/fl), were challenged by either the murine hepatitis virus type 3 (MHV3) or poly I:C, a synthetic analog of double-stranded RNA mimicking viral pathogen-associated molecular pattern. Ripk1^LPC-KO mice developed more severe symptoms at early stage of the MHV3-induced fulminant hepatitis. Similarly, administration of poly I:C only triggered increase of systemic transaminases in Ripk1^LPC-KO mice, reflecting liver damage through induced apoptosis as illustrated by cleaved-caspase 3 labeling of liver tissue sections. Neutralization of TNF-α or prior depletion of macrophages were able to prevent the appearance of apoptosis of hepatocytes in poly I:C-challenged Ripk1^LPC-KO mice. Moreover, poly I:C never induced direct hepatocyte death in primary culture whatever the murine genotype, while it always stimulated an anti-viral response. Our investigations demonstrated that RIPK1 protects hepatocytes from TNF-α secreted from macrophages during viral induced fulminant hepatitis. These data emphasize the potential worsening risks of an HBV infection in people with polymorphism or homozygous amorphic mutations already described for the RIPK1 gene.

The hepatoprotective effects of Radix Bupleuri extracts against D-galactosamine/lipopolysaccharide induced liver injury in hybrid grouper (Epinephelus lanceolatus♂ × Epinephelus fuscoguttatus♀)

The present study is aiming at evaluating the hepatoprotective of Radix Bupleuri extracts (RBE) on the d-galactosamine/lipopolysaccharide (D-GalN/LPS) induced liver injury of hybrid grouper in vitro and in vivo. In vitro, RBE (0, 200, 400 and 800 μg/ml) was added to the hybrid grouper primary hepatocytes before (pretreatment) the incubation of the hepatocytes with D-GalN (20 mM) plus LPS (1 μg/ml) in the culture medium. RBE at concentrations of 200, 400 and 800 μg/ml significantly improved cell viability and inhibited the elevation of TNF-α, IL-1β and IL-6 and significantly down-regulated the caspase-3, caspase-9 and P53 mRNA levels. In vivo administration of RBE at the doses of 0, 200, 400, 800 and 1600 mg/kg in the diet for 8 weeks prior to D-GalN (500 mg/kg) and LPS (20 μg/kg) intoxication. The study indicated that the RBE not only ameliorated liver injury, as evidenced by well-preserved liver architecture, but also significantly increased hepatic antioxidant enzymes activities in the D-GalN/LPS-induced liver injury animal model. Further demonstrating the protective effects of the RBE, we found that pretreatment with the RBE up-regulated the expression of antioxidant genes (GPx and MnSOD), while down-regulated apoptosis-related genes (caspase-3, caspase-9 and P53), immune related genes (MHC2 and TLR3) and pro-inflammatory cytokines (TOR and IKKα) mRNA expression in the liver of hybrid grouper. In brief, the present study showed that RBE can protect hepatocyte injury induced by D-GalN/LPS through elevating antioxidant enzyme activity and suppressing apoptosis and immune inflammatory responses. The results support the use of RBE as a hepatoprotective in fish.

Combination of LC/MS and GC/MS based metabolomics to study the hepatotoxic effect of realgar nanoparticles in rats

Realgar nanoparticles (NPs) are increasingly used as therapeutic agents for their enhanced anti-proliferation effect and cytotoxicity on cancer cells. However, the alteration of particle size may enhance biological reactivity as well as toxicity. A LC/MS and GC/MS based metabolomics approach was employed to explore the mechanism of realgar NPs-induced hepatotoxicity and identify potential biomarkers. Male Sprague-Dawley rats were administrated intragastrically with realgar or realgar NPs at a dose of 1.0 g·kg^-1·d^-1 for 28 days and toxic effects of realgar NPs on liver tissues were examined by biochemical indicator analysis and histopathologic examination. Increased levels of serum enzymes and high hepatic steatosis were discovered in the realgar NPs treated group. Multivariate data analysis revealed that rats with realgar NPs-induced hepatotoxicity could be distinctively differentiated from the animals in the control and realgar treated groups. In addition, 21 and 32 endogenous metabolites were apparently changed in the serum and live extracts, respectively. Realgar NPs might induce free fatty acid and triglyceride accumulation, resulting in hepatotoxicity. In conclusion, the present study represents the first comprehensive LC/MS- and GC/MS-based metabolomics analysis of realgar NPs-induced hepatotoxicity, which may help further research of nanotoxicity.

The extracellular domain of Staphylococcus aureus LtaS binds insulin and induces insulin resistance during infection

Insulin resistance is a risk factor for obesity and diabetes and predisposes individuals to Staphylococcus aureus colonization; however, the contribution of S. aureus to insulin resistance remains unclear. Here, we show that S. aureus infection causes impaired glucose tolerance via secretion of an insulin-binding protein extracellular domain of LtaS, eLtaS, which blocks insulin-mediated glucose uptake. Notably, eLtaS transgenic mice (eLtaS ^trans ) exhibited a metabolic syndrome similar to that observed in patients, including increased food and water consumption, impaired glucose tolerance and decreased hepatic glycogen synthesis. Furthermore, transgenic mice showed significant metabolic differences compared to their wild-type counterparts, particularly for the early insulin resistance marker α-hydroxybutyrate. We subsequently developed a full human monoclonal antibody against eLtaS that blocked the interaction between eLtaS and insulin, which effectively restored glucose tolerance in eLtaS ^trans and S. aureus-challenged mice. Thus, our results reveal a mechanism for S. aureus-induced insulin resistance.

Isovitexin alleviates liver injury induced by lipopolysaccharide/d-galactosamine by activating Nrf2 and inhibiting NF-κB activation

The aim of this study was to investigate the protective effects and mechanism of isovitexin, a glycosylflavonoid isolated from rice hulls of Oryza sativa, on Lipopolysaccharide (LPS)/d-galactosamine (D-Gal)-induced acute liver injury. The mice were randomly divided into five groups: control group, LPS/D-Gal group, and LPS/D-Gal + isovitexin groups. The mice of LPS/D-Gal group were received of LPS (50 μg/kg) and D-gal (800 mg/kg) intraperitoneal. The mice of LPS/D-Gal + isovitexin groups were received isovitexin (25, 50, 100 mg/kg) 1 h before LPS/D-Gal treatment. The results showed that the severity of liver injury was attenuated by treatment of isovitexin, as confirmed by the decreased liver histopathologic changes, as well as serum AST and ALT levels. Furthermore, the levels of TNF-α in serum and liver tissues, MPO activity and MDA content were significantly inhibited by isovitexin. In addition, isovitexin significantly attenuated NF-κB phosphorylation induced by LPS/D-Gal. The expression of Nrf2 and HO-1 were significantly up-regulated by isovitexin. In conclusion, isovitexin could protect against LPS/D-Gal-induced liver injury by inhibiting inflammatory and oxidative responses. Isovitexin also had protective effects against carbon tetrachloride (CCl₄)-induced liver injury. Isovitexin may used as a potential agent for the treatment of liver injury.

Lycopene Prevents Mitochondrial Dysfunction during d-Galactosamine/Lipopolysaccharide-Induced Fulminant Hepatic Failure in Albino Rats

Functional perturbation of mitochondria is associated with fulminant hepatic failure (FHF). d-Galactosamine/lipopolysaccharide (d-GalN/LPS)-induced FHF is a renowned model to evaluate the efficacy of hepatoprotective agents. Lycopene is an antioxidant and phytonutrient from the carotenoid family. The health benefits of lycopene are prominent against cancer and cardiovascular, lung, liver, and skin problems. Recent studies have demonstrated the hepatoprotective, antidyslipidemic, and antioxidant roles of lycopene. The current study was designed to appraise the ability of lycopene to prevent mitochondrial dysfunction during the d-GalN/LPS-induced FHF. The administration of d-GalN/LPS (300 mg and 30 μg/kg body weight, respectively) to the experimental rats induced several disturbances in mitochondrial function. The lipid peroxide and hydrogen peroxide levels were increased (p < 0.05). The activities of mitochondrial antioxidants, tricarboxylic acid (TCA) cycle, and electron transport chain enzymes and the cellular adenosine triphosphate (ATP) content were decreased (p < 0.05). Lycopene (10 mg/kg body weight for 6 days) pretreatment attenuated lipid peroxidation and prohibited the excessive synthesis of hydrogen peroxide. The d-GalN/LPS-induced impairment in ATP production and increased enzyme activities were effectively prevented by the lycopene administration. The lycopene-mediated mitochondrial protection was mainly ascribed to the strong antioxidant potential of this phytonutrient. Molecular modeling results obtained show evidence that lycopene inhibits several lipoxygenases and provides rationale for the observed prevention of lipid peroxidation in the mitochondrial membrane. The carotenoid lycopene combatted oxidative stress, scavenged free radicals, prevented ROS generation, and inhibited the toxic effects of d-GalN/LPS during FHF.

Combinatory Evaluation of Transcriptome and Metabolome Profiles of Low Temperature-induced Resistant Ascites Syndrome in Broiler Chickens

To select metabolic biomarkers and differentially expressed genes (DEGs) associated with resistant-ascites syndrome (resistant-AS), we used innovative techniques such as metabolomics and transcriptomics to comparatively examine resistant-AS chickens and AS controls. Metabolomic evaluation of chicken serum using ultra-performance liquid chromatography-quadruple time-of-flight high-sensitivity mass spectrometry (UPLC-QTOF/HSMS) showed significantly altered lysoPC(18:1), PE(18:3/16:0), PC(20:1/18:3), DG(24:1/22:6/0:0), PS(18:2/18:0), PI(16:0/16:0), PS(18:0/18:1), PS(14:1/14:0), dihydroxyacetone, ursodeoxycholic acid, tryptophan, L-valine, cycloserine, hypoxanthine, and 4-O-Methylmelleolide concentrations on day 21 and LysoPC(18:0), LysoPE(20:1/0:0), LysoPC(16:0), LysoPE(16:0/0:0), hypoxanthine, dihydroxyacetone, 4-O-Methylmelleolide, LysoPC(18:2), and PC(14:1/22:1) concentrations on day 35, between the susceptible and resistant groups. Compared to the susceptible group, transcriptomic analysis of liver samples using RNA-seq revealed 413 DEGs on day 21 and 214 DEGs on day 35 in the resistant group. Additional evaluations using gene ontology (GO) indicate that significant enrichment occurred in the oxygen transportation, defensive reactions, and protein modifications of the decreased DEGs as well as in the cell morphological formation, neural development, and transforming growth factor (TGF)-beta signalling of the increased DEGs on day 21. Oxygen transportation was also significantly enriched for downregulated DEGs on day 35. The combinatory evaluation of the metabolome and the transcriptome suggests the possible involvement of glycerophospholipid metabolism in the development of resistant-AS in broilers.

A metabonomic investigation on the biochemical perturbation in post-stroke patients with depressive disorder (PSD)

A metabonomics study based on GC/MS and multivariate statistical analysis was performed involving 28 post stroke depressed (PSD) patients, 27 post-stroke non-depressed (PSND) patients and 33 healthy subjects to investigate the biochemical perturbation in their plasma samples. The outcome of this study showed that there was distinctive metabolic profile for PSD patients. Seven sentinel metabolites showed marked perturbations in PSD patients' blood. The introduction of metabonomics approach may provide a novel metabonomic insight about PSD and the sentinel metabolites for classifying PSD.

Ifit1 Protects Against Lipopolysaccharide and D-galactosamine-Induced Fatal Hepatitis by Inhibiting Activation of the JNK Pathway

Treatment of mice with lipopolysaccharide (LPS) and the liver-specific transcriptional inhibitor D-(+)-galactosamine (GalN) induces fatal hepatitis, which is mediated by tumor necrosis factor α (TNF-α) and characterized by massive hepatic apoptosis. Previous studies suggest that GalN increases the sensitivity to LPS/TNF-α, probably by blocking the transcription of protective factors, but the identity of most of these factors is still unclear. Here, we report that Ifit1 protects against LPS/GalN-induced fatal hepatitis. Forced expression of Ifit1 in hepatocytes significantly diminished TNF-α-mediated apoptosis. Moreover, targeted expression of Ifit1 in the liver by recombinant adeno-associated virus serotype 8 protected mice from LPS/GalN-induced lethal hepatitis, which was associated with the inhibition of TNF-α-mediated activation of the c-Jun N-terminal kinase (JNK)-Bim cascade. Furthermore, Ifit1 bound to a scaffolding protein Axin and inhibited its function to mediate JNK activation. Together, our data demonstrate that Ifit1 is a novel protective factor that inhibits LPS/GalN-induced (TNF-α-mediated) fatal hepatitis, suggesting that Ifit1 is a potential therapeutic target for treatment of inflammatory liver diseases.

Negative regulation of the inflammasome: keeping inflammation under control

In addition to its roles in controlling infection and tissue repair, inflammation plays a critical role in diverse and distinct chronic diseases, such as cancer, metabolic syndrome, and neurodegenerative disorders, underscoring the harmful effect of an uncontrolled inflammatory response. Regardless of the nature of the stimulus, initiation of the inflammatory response is mediated by assembly of a multimolecular protein complex called the inflammasome, which is responsible for the production of inflammatory cytokines, such as interleukin-1β (IL-1β) and IL-18. The different stimuli and mechanisms that control inflammasome activation are fairly well understood, but the mechanisms underlying the control of undesired inflammasome activation and its inactivation remain largely unknown. Here, we review recent advances in our understanding of the molecular mechanisms that negatively regulate inflammasome activation to prevent unwanted activation in the resting state, as well as those involved in terminating the inflammatory response after a specific insult to maintain homeostasis.

Dietary fibers influence the intestinal SCFAs and plasma metabolites profiling in growing pigs

Dietary fibers (DFs), widely used as food additives to replace fat, can benefit metabolic disorders.

Postprandial metabolomics: A pilot mass spectrometry and NMR study of the human plasma metabolome in response to a challenge meal

The study of postprandial metabolism is relevant for understanding metabolic diseases and characterizing personal responses to diet. We combined three analytical platforms - gas chromatography-mass spectrometry (GC-MS), liquid chromatography-mass spectrometry (LC-MS) and nuclear magnetic resonance (NMR) - to validate a multi-platform approach for characterizing individual variation in the postprandial state. We analyzed the postprandial plasma metabolome by introducing, at three occasions, meal challenges on a usual diet, and 1.5 years later, on a modified background diet. The postprandial response was stable over time and largely independent of the background diet as revealed by all three analytical platforms. Coverage of the metabolome between NMR and GC-MS included more polar metabolites detectable only by NMR and more hydrophobic compounds detected by GC-MS. The variability across three separate testing occasions among the identified metabolites was in the range of 1.1-86% for GC-MS and 0.9-42% for NMR in the fasting state at baseline. For the LC-MS analysis, the coefficients of variation of the detected compounds in the fasting state at baseline were in the range of 2-97% for the positive and 4-69% for the negative mode. Multivariate analysis (MVA) of metabolites detected with GC-MS revealed that for both background diets, levels of postprandial amino acids and sugars increased whereas those of fatty acids decreased at 0.5 h after the meal was consumed, reflecting the expected response to the challenge meal. MVA of NMR data revealed increasing postprandial levels of amino acids and other organic acids together with decreasing levels of acetoacetate and 3-hydroxybutanoic acid, also independent of the background diet. Together these data show that the postprandial response to the same challenge meal was stable even though it was tested 1.5 years apart, and that it was largely independent of background diet. This work demonstrates the efficacy of a multi-platform metabolomics approach followed by multivariate and univariate data analysis for a broad-scale screen of the individual metabolome, particularly for studies using repeated measures to determine dietary response phenotype.

GC-MS-based plasma metabolomic investigations of morphine dependent rats at different states of euphoria, tolerance and naloxone-precipitated withdrawal

Long-term or excessive application of morphine leads to tolerance and addiction, which hindered its conventional applications as a drug. Although tremendous progress has been made on the mechanisms of morphine, crucial evidence elaborating the neurobiological basis of tolerance and dependence is still lacking. To further explore the physiological adaptions during morphine's application, a systematic screening of small molecules in blood has been carried out. The plasma of morphine dependent rats was collected at different time points with or without naloxone treatment, and was analyzed by gas chromatography-mass spectrometry (GC-MS). Partial least squares discriminate analysis (PLS-DA) and the Student's t Tests with the false discovery rate (FDR) correction were conducted on the normalized data for the distinction of groups and the identification of the most contributed metabolites. Clear separation is observed between different treatments, and 29 out of 41 metabolites changes significantly compared with the corresponding controls. The concentration of threonine, glycine, serine, beta-d-glucose and oxalic acid are consistently changed in all morphine treated groups compared with controls. Through this experiment we find characteristic metabolites in different dependent states and discuss the possible compensation effects. The interpretation of these metabolites would throw light on the biological effects of morphine and reveal the possibilities to become marker of morphine addiction.

A metabolomic study of the PPARδ agonist GW501516 for enhancing running endurance in Kunming mice

Exercise can increase peroxisome proliferator-activated receptor-δ (PPARδ) expression in skeletal muscle. PPARδ regulates muscle metabolism and reprograms muscle fibre types to enhance running endurance. This study utilized metabolomic profiling to examine the effects of GW501516, a PPARδ agonist, on running endurance in mice. While training alone increased the exhaustive running performance, GW501516 treatment enhanced running endurance and the proportion of succinate dehydrogenase (SDH)-positive muscle fibres in both trained and untrained mice. Furthermore, increased levels of intermediate metabolites and key enzymes in fatty acid oxidation pathways were observed following training and/or treatment. Training alone increased serum inositol, glucogenic amino acids, and branch chain amino acids. However, GW501516 increased serum galactose and β-hydroxybutyrate, independent of training. Additionally, GW501516 alone raised serum unsaturated fatty acid levels, especially polyunsaturated fatty acids, but levels increased even more when combined with training. These findings suggest that mechanisms behind enhanced running capacity are not identical for GW501516 and training. Training increases energy availability by promoting catabolism of proteins, and gluconeogenesis, whereas GW501516 enhances specific consumption of fatty acids and reducing glucose utilization.

Galactose protects hepatocytes against TNF-α-induced apoptosis by promoting activation of the NF-κB signaling pathway in acute liver failure

Saccharides are reported to protect hepatocytes from acute liver injury through distinct mechanisms. To date, the protective role of galactose against acute liver injury induced by lipopolysaccharide (LPS) and D-galactosamine (D-GalN) has been attributed to competition with D-GalN. Here, we showed that in addition to its effects on LPS/D-GalN and tumor necrosis factor alpha (TNF-α)/D-GalN models, galactose improves hepatic injury in mice challenged with LPS alone or TNF-α/actinomycin D. Consistent with this result, galactose enhanced the viability of TNF-α-stimulated Chang Liver and Hu7.5 hepatic cell lines. Specifically, galactose prevented TNF-α-induced apoptosis of hepatocytes through promoting phosphorylation of nuclear factor kappa B (NF-κB) p65. Additionally, galactose enhanced expression of the anti-apoptotic genes, c-IAP1 and A20, and inhibited cleavage of caspase-8 and caspase-3. These findings collectively suggest that galactose prevents TNF-α-induced liver injury through activation of the NF-κB signaling pathway. Considering that monosaccharides protect against liver injury via distinct mechanisms, these compounds may represent a promising clinical approach to treat acute liver failure.

Inflammasomes in pancreatic physiology and disease

In this review we summarize the role of inflammasomes in pancreatic physiology and disease with a focus on acute pancreatitis where much recent progress has been made. New findings have identified inducers of and cell specificity of inflammasome component expression in the pancreas, the contribution of inflammasome-regulated effectors to pancreatitis, and metabolic regulation of inflammasome activation, which are strong determinants of injury in pancreatitis. New areas of pancreatic biology will be highlighted in the context of our evolving understanding of gut microbiome- and injury-induced inflammasome priming, pyroptosis, and innate immune-mediated regulation of cell metabolism.

Hepatoprotective effect of Commiphora myrrha against d-GalN/LPS-induced hepatic injury in a rat model through attenuation of pro inflammatory cytokines and related genes

CONTEXT

Commiphora myrrha (Burseraceae), a shrub resembling a small tree, has been used for several centuries for the treatment of various diseases.

OBJECTIVE

This study investigates the hepatoprotective activity of C. myrrha ethanol extract against d-galactosamine/lipopolysaccharide (d-GalN/LPS)-induced acute hepatic injury in an animal model.

MATERIALS AND METHODS

Rats were pretreated with ethanolic extract C. myrrha (250 and 500 mg/kg; p.o.) for 7 d prior to the induction of an acute phase response by d-GalN/LPS. Animals were sacrificed 24 h after d-GalN/LPS (800 mg/kg and 50 µg/kg i.p.) administration for the biochemical and histological analyses.

RESULTS

The administration of d-GalN/LPS increased plasma aminotransferases (174.47 ± 4.5761 and 260.96 ± 1.9839 µkat/l) and total bilirubin levels (1.012 ± 0.0288 mg/dl), which were attenuated by C. myrrha treatment. Hepatic lipid peroxidation activity and nitric oxide content also increased, while the antioxidant activity measured by GSH (0.76 nmol/g protein), SOD (81.91 U/mg protein), and CAT (15.78 U/mg protein) was reduced. Commiphora myrrha provided significant restoration of GSH (0.815 nmol/gm protein), SOD (140.57 U/mg protein), and CAT (27.02 U/mg protein) levels. Furthermore, the acute phase response elicited by d-GalN/LPS administration enhanced mRNA expressions of TNF-α, IL-6, IL-10, iNOS-2, and HO-1, which were ameliorated by C. myrrha treatment.

DISCUSSION AND CONCLUSION

These findings indicate that C. myrrha considerably reduces the oxidative stress of d-GalN/LPS-induced hepatic injury via multiple pathways including adown regulation of inflammatory mediators and cytokines. Such a property might be sufficient to combat cellular damage caused by various conditions that resemble fulminant hepatitis and could be of a potential clinical application.

Activation of N-methyl-d-aspartate receptor downregulates inflammasome activity and liver inflammation via a β-arrestin-2 pathway

Activation of the cytosolic inflammasome machinery is responsible for acute and chronic liver inflammation, but little is known about its regulation. The N-methyl-d-aspartate (NMDA) receptor families are heterotetrameric ligand-gated ion channels that are activated by a range of metabolites, including aspartate, glutamate, and polyunsaturated fatty acids. In the brain NMDA receptors are present on neuronal and nonneuronal cells and regulate a diverse range of functions. We tested the role of the NMDA receptor and aspartate in inflammasome regulation in vitro and in models of acute hepatitis and pancreatitis. We demonstrate that the NMDA receptor is present on Kupffer cells, and their activation on primary mouse and human cells limits inflammasome activation by downregulating NOD-like receptor family, pyrin domain containing 3 and procaspase-1. The NMDA receptor pathway is active in vivo, limits injury in acute hepatitis, and can be therapeutically further activated by aspartate providing protection in acute inflammatory liver injury. Downregulation of inflammasome activation by NMDA occurs via a β-arrestin-2 NF-kβ and JNK pathway and not via Ca(2+) mobilization. We have identified the NMDA receptor as a regulator of inflammasome activity in vitro and in vivo. This has identified a new area of immune regulation associated by metabolites that may be relevant in a diverse range of conditions, including nonalcoholic steatohepatitis and total parenteral nutrition-induced immune suppression.

Lactate reduces liver and pancreatic injury in Toll-like receptor- and inflammasome-mediated inflammation via GPR81-mediated suppression of innate immunity

BACKGROUND & AIMS

The NACHT, LRR, and pyrin domain-containing protein 3 (NLRP3) inflammasome induces inflammation in response to organ injury, but little is known about its regulation. Toll-like receptors (TLRs) provide the first signal required for activation of the inflammasome and stimulate aerobic glycolysis to generate lactate. We examined whether lactate and the lactate receptor, Gi-protein-coupled receptor 81 (GPR81), regulate TLR induction of signal 1 and limit inflammasome activation and organ injury.

METHODS

Primary mouse macrophages and human monocytes were incubated with TLR4 agonists and lactate and assayed for levels of pro-interleukin (IL)1β, NLRP3, and caspase-1 (CASP1); release of IL1β; and activation of nuclear factor-κB (NF-κB) and caspase-1. Small interfering RNAs were used to reduce levels of GPR81 and arrestin β-2 (ARRB2), and an NF-κB luciferase reporter transgene was transfected in RAW 264.7 cells. Cell lysates were analyzed by immunoprecipitation with an antibody against GPR81. Acute hepatitis was induced in C56BL/6N mice by administration of lipopolysaccharide and D-galactosamine. Acute pancreatitis was induced by administration of lipopolysaccharide and cerulein. Some mice were given intraperitoneal injections of sodium lactate or small interfering RNA against Gpr81. Activation of NF-κB in tissue macrophages was assessed in mice that expressed a reporter transgene.

RESULTS

In macrophages and monocytes, increasing concentrations of lactate reduced TLR4-mediated induction of Il1B, Nlrp3, and Casp1; activation of NF-κB; release of IL1β; and cleavage of CASP1. GPR81 and ARRB2 physically interacted and were required for these effects. The administration of lactate reduced inflammation and organ injury in mice with immune hepatitis; this reduction required Gpr81 dependence in vivo. Lactate also prevented activation of NF-κB in macrophages of mice, and, when given after injury, reduced the severity of acute pancreatitis and acute liver injury.

CONCLUSIONS

Lactate negatively regulates TLR induction of the NLRP3 inflammasome and production of IL1β, via ARRB2 and GPR81. Lactate could be a promising immunomodulatory therapy for patients with acute organ injury.

The potential biomarker panels for identification of Major Depressive Disorder (MDD) patients with and without early life stress (ELS) by metabonomic analysis

Objective

The lack of the disease biomarker to support objective laboratory tests still constitutes a bottleneck in the clinical diagnosis and evaluation of major depressive disorder (MDD) and its subtypes. We used metabonomic techniques to screen the diagnostic biomarker panels from the plasma of MDD patients with and without early life stress (ELS) experience.

Methods

Plasma samples were collected from 25 healthy adults and 46 patients with MDD, including 23 patients with ELS and 23 patients without ELS. Furthermore, gas chromatography/mass spectrometry (GC/MS) coupled with multivariate statistical analysis was used to identify the differences in global plasma metabolites among the 3 groups.

Results

The distinctive metabolic profiles exist either between healthy subjects and MDD patients or between the MDD patients with ELS experience (ELS/MDD patients) and the MDD patients without it (non-ELS/MDD patients), and some diagnostic panels of feature metabolites' combination have higher predictive potential than the diagnostic panels of differential metabolites.

Conclusions

These findings in this study have high potential of being used as novel laboratory diagnostic tool for MDD patients and it with ELS or not in clinical application.

Metabolite profiling and pathway analysis of acute hepatitis rats by UPLC-ESI MS combined with pattern recognition methods

BACKGROUND & AIMS

Metabolomics is comprehensive analysis of low-molecular-weight endogenous metabolites in a biological sample. It could enable mapping of perturbations of early biochemical changes in diseases and hence provide an opportunity to develop predictive biomarkers that could provide valuable insights into the mechanisms of diseases. The aim of this study was to elucidate the changes in endogenous metabolites and to phenotype the metabolic profiling of d-galactosamine (GalN)-inducing acute hepatitis in rats by UPLC-ESI MS.

METHODS

The systemic biochemical actions of GalN administration (ip, 400 mg/kg) have been investigated in male wistar rats using conventional clinical chemistry, liver histopathology and metabolomic analysis of UPLC- ESI MS of urine. The urine was collected predose (-24 to 0 h) and 0-24, 24-48, 48-72, 72-96 h post-dose. Mass spectrometry of the urine was analysed visually and via conjunction with multivariate data analysis.

RESULTS

Results demonstrated that there was a time-dependent biochemical effect of GalN dosed on the levels of a range of low-molecular-weight metabolites in urine, which was correlated with developing phase of the GalN-inducing acute hepatitis. Urinary excretion of beta-hydroxybutanoic acid and citric acid was decreased following GalN dosing, whereas that of glycocholic acid, indole-3-acetic acid, sphinganine, n-acetyl-l-phenylalanine, cholic acid and creatinine excretion was increased, which suggests that several key metabolic pathways such as energy metabolism, lipid metabolism and amino acid metabolism were perturbed by GalN.

CONCLUSION

This metabolomic investigation demonstrates that this robust non-invasive tool offers insight into the metabolic states of diseases.

UPLC-MS-based serum metabonomics for identifying acute liver injury biomarkers in Chinese miniature pigs

Metabonomics has emerged as an important technology for exploring the underlying mechanisms of diseases and screening for biomarkers. In this investigation, to comprehensively assess metabolite changes in D-galactosamine (GalN)-induced liver injury in Chinese miniature pigs and to increase our understanding of physiological changes in normal and pathological states, we used ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) to analyze metabolites and identify biomarkers in serum. Blood samples were collected both from 18 h after GalN treatment group and control group pigs. We performed multivariate analyses on the metabolite profiles to identify potential biomarkers of acute liver injury, which were then confirmed by tandem MS. Based on "variable of importance in the project" (VIP) values and S-plots, four groups of biomarkers were identified--namely conjugated bile acids, lysophosphatidylcholines (LPCs), phosphatidylcholines (PCs) and fatty acid amides (FAAs)--that were present at significantly different levels in the control and GalN-induced groups. LPCs, PCs, and FAAs showed marked decreases in the GalN-treated group, whereas conjugated bile acids in the treated group showed considerable increases. Taken together, our results suggested that obvious metabolic disturbances occur during acute liver injury, which provided novel insights into the molecular mechanism(s) of D-galactosamine (GalN)-induced liver injury, and will facilitate future research and management of liver injury.

Discovery of potential biomarkers in exhaled breath for diagnosis of type 2 diabetes mellitus based on GC-MS with metabolomics

Eight breath biomarkers of T2DM were discovered by a new SPME-GC-MS based metabolic profiling tool.

Metabonomic analysis of liver tissue from BALB/c mice with D-galactosamine/lipopolysaccharide-induced acute hepatic failure

Background

Compared with biofluids, target tissues and organs more directly reflect the pathophysiological state of a disease process. In this study, a D-galactosamine (GalN) / lipopolysaccharide (LPS)-induced mouse model was constructed to investigate metabonomics of liver tissue and directly characterize metabolic changes in acute liver failure (ALF).

Methods

After pretreatment of liver tissue, gas chromatography coupled to time-of-flight mass spectrometry (GC/TOFMS) was used to separate and identify the liver metabolites. Partial least squares – discriminant analysis models were constructed to separate the ALF and control groups and to find those compounds whose liver levels differed significantly between the two groups.

Results

Distinct clustering was observed between the ALF and control mice. Fifty-eight endogenous metabolites were identified. Compared with the control mice, many metabolites, including sugars, amino acids, fatty acids, and organic acids, underwent significant changes in the ALF group, some of which differed from changes observed in plasma. Significant reduction of some important intermediate metabolites indicates that production of ketone bodies, the tricarboxylic acid and urea cycles, gluconeogenesis, glycolysis and pentose phosphate pathways are inhibited after GalN/LPS administration.

Conclusions

GC/TOFMS can be a powerful technique to perform metabonomic studies of liver tissue. GalN/LPS treatment can severely disturb substance metabolism in the liver, with different effects on metabolites compared with those observed in the plasma.

Plasma metabolic biomarkers for syndrome of phlegm and blood stasis in hyperlipidemia and atherosclerosis

OBJECTIVE

To explore the plasma metabolite profiles in patients with the syndrome of phlegm and blood stasis in hyperlipidemia and atherosclerosis (As), and to search for the metabolic biomarkers of the syndrome.

METHODS

The plasma metabolite profiles of 31 patients with the syndrome of phlegm and blood stasis in hyperlipidemia and As, 6 patients with syndromes without phlegm and blood stasis, and 10 healthy subjects were analyzed by gas chromatography-mass spectrometry (GC-MS). Partial least squares-discriminant analyses (PLS-DA) were used to carry out the pattern-recognition analyses of the data. The plasma metabolic biomarkers of patients were obtained by variable importance plot value (VIP value) and Student's t-test. The structures of biomarkers were defined by the National Institute of Standards and Technology (NIST) database.

RESULTS

PLS-DA score plots of plasma metabolomes did not show overlap between the phlegm-blood stasis syndrome group and syndromes without phlegm and blood stasis group, whereas significant differences in the concentrations in the plasma of 5 metabolites were found (P < 0.05). They were identified as urine, isoleucine, glucuronic acid, palmitic acid and glycerol by searching in NIST database. The concentrations of four metabolites in the plasma of patients with syndrome of phlegm and blood stasis were higher than those with syndromes without phlegm and blood stasis, whereas the glycerol concentration was lower.

CONCLUSION

Compared with patients with syndromes without phlegm and blood stasis, five metabolites showed abnormal levels in patients with the syndrome of phlegm and blood stasis. These metabolites could be diagnostic and prognostic biomarkers.

Selection of candidate radiation biomarkers in the serum of rats exposed to gamma-rays by GC/TOFMS-based metabolomics

In the study, gas chromatography/time-of-flight mass spectrometry (GC/TOFMS) techniques coupled with principal components analysis (PCA) were used to investigate metabolite perturbations in the serum of the rats exposed to 0.75, 3 or 8 Gy gamma rays. Male standard deviation rats were gamma-irradiated at doses of 0.75, 3 and 8 Gy (1.9 Gy min(-1)) or sham-irradiated. Serum samples were collected over the first 24 h under the exposure to irradiation in order to analyse the samples by GC/TOFMS. And multivariate data were analysed by PCA. The composition of metabolites in serum yielded distinct metabolomic phenotypes for 0.75, 3 and 8 Gy at 24 h after irradiation. Nine serum metabolites were significantly altered as a result of radiation exposure. Up-regulated metabolites included inositol, serine, lysine, glycine, threonine and glycerol; down-regulated metabolites included isocitrate, gluconic acid and stearic acid. The nine metabolites were significantly altered after ionising radiation for they may be the potential biomarkers for the diagnosis of radiation injury.

Extraction, derivatization, and determination of metabolome in human macrophages

A GC/TOF-MS was applied to the determination of metabolites in human macrophages. The extraction conditions and quenching conditions were investigated and optimized. The results indicated that 0.9% w/v sodium chloride at 4°C was the most favorable condition to quench macrophage, 1 mL 50% ACN for 2 min in ice bath was the optimal condition to extract 5 × 10(6) cells. Two hundred six peaks could be detectable with peak area over 50 using this method. Among these peaks, 45 peaks with the similarity over 700 were identified using standard compounds for endogenous metabolites. Thirty-seven out of 45 metabolites could be quantified directly by this method. Twenty metabolites were selected randomly, and 15 amino acids were used for method validation. The correlation coefficients (r) ranging from 0.9902 to 0.9977 were obtained for 15 amino acids in the range of 2.35-150.20 μg/mL. The intraday and interday precisions were lower than 19.90% for the randomly selected 20 endogenous metabolites. Using this development method and multivariate statistical technique, several potential biomarkers were found from human macrophages infected by different Mycobacterium tuberculosis (M. tuberculosis) strains. The results suggest that the method could be applied to the investigation of the pathogenicity of tuberculosis.

Metabolic profiles characterizing different phenotypes of polycystic ovary syndrome: plasma metabolomics analysis

BACKGROUND

Polycystic ovary syndrome (PCOS) is a heterogeneous endocrine disorder accompanied with an increased risk of developing type 2 diabetes mellitus and cardiovascular disease; despite being a common condition, the pathogenesis of PCOS remains unclear. Our aim was to investigate the potential metabolic profiles for different phenotypes of PCOS, as well as for the early prognosis of complications.

METHODS

A total of 217 women with PCOS and 48 healthy women as normal controls were studied. Plasma samples of subjects were tested using two different analytical platforms of metabolomics: 1H nuclear magnetic resonance (NMR) and gas chromatography/time-of-flight mass spectrometry (GC/TOF-MS).

RESULTS

Our results showed that carbohydrate, lipid and amino acid metabolisms were influenced in PCOS. The levels of lactate, long-chain fatty acids, triglyceride and very low-density lipoprotein were elevated, while glucose, phosphatidylcholine and high-density lipoprotein (HDL) concentrations were reduced in PCOS patients as compared with controls. Additionally, the levels of alanine, valine, serine, threonine, ornithine, phenylalanine, tyrosine and tryptophan were generally increased, whereas the levels of glycine and proline were significantly reduced in PCOS samples compared to controls. Furthermore, the ratio of branched-chain amino acid to aromatic amino acid concentrations (BCAA/AAA) in PCOS plasma was significantly reduced in PCOS patients and was insusceptible to obesity and insulin sensitivity.

CONCLUSIONS

Our results suggested that the enhanced glycolysis and inhibited tricarboxylic acid cycle (TAC) in women with PCOS. Decrease of BCAA/AAA ratio was directly correlated with the development of PCOS. Ovulatory dysfunction of PCOS patients was associated with raised production of serine, threonine, phenylalanine, tyrosine and ornithine. Elevated levels of valine and leucine, and decreased concentrations of glycine in PCOS plasma could contribute to insulin sensitivity and could be considered as the potential biomarkers for long-term risk assessment of diabetes mellitus.

Arachidonic acid: a bridge between traumatic brain injury and fracture healing

Traumatic brain injury (TBI) is associated with enhanced osteogenesis. The aim of this study was to investigate the effect of serum from TBI rats on fracture healing. Results from this study showed that the serum from TBI rats enhanced the expression of bone gamma carboxyglutamate protein (BGLAP), and promoted in vitro proliferation of MC3T3-E1 cells, a mouse osteoblastic cell line. Furthermore, gas chromatography/mass spectrometry (GC/MS) coupled with multivariate statistical analysis was used to identify the changes in global serum metabolites after TBI. We found that arachidonic acid (AA) was significantly enhanced in serum metabolites in TBI subjects, while hydroxybutyric acid, leucine, malic acid, 5-oxyproline, isocitric acid, mannose, and uric acid were reduced. Finally, we examined the effects of AA on BGLAP expression and cell proliferation in MC3T3-E1 cells. We found that BGLAP expression and proliferation of osteoblasts were positively regulated in the presence of AA. These findings suggest that the increased AA in serum after TBI may play a key role in enhancing the speed of fracture healing.

Serum UPLC-MS/MS metabolic profiling in an experimental model for acute-liver injury reveals potential biomarkers for hepatotoxicity

A key interest in clinical diagnosis and pharmaceutical industry is to have a repertoire of noninvasive biomarkers to-individually or in combination-be able to infer or predict the degree of liver injury caused by pathological conditions or drugs. Metabolomics-a comprehensive study of global metabolites-has become a highly sensitive and powerful tool for biomarker discovery thanks to recent technological advances. An ultra-performance liquid chromatography/time-of-flight tandem mass spectrometry (UPLC/TOF MS/MS)-based metabolomics approach was employed to investigate sera from galactosamine-treated rats to find potential biomarkers for acute liver injury. Hepatic damage was quantified by determining serum transaminase activity and in situ liver histological lesions. Principal component analysis in combination with coefficient of correlation analysis was used for biomarker selection and identification. According to the data, serum levels of several metabolites including glucose, amino acids, and membrane lipids were significantly modified, some of them showing a high correlation with the degree of liver damage determined by histological examination of the livers. In conclusion, this study supports that UPLC-MS/MS based serum metabolomics in experimental animal models could be a powerful approach to search for biomarkers for drug- or disease-induced liver injury.

Differential Oxidative Stress Responses to D-Galactosamine-Lipopolysaccharide Hepatotoxicity Based on Real Time PCR Analysis of Selected Oxidant/Antioxidant and Apoptotic Gene Expressions in Rat

Oxidative stress and apoptosis are proposed mechanisms of cellular injury in studies of xenobiotic hepatotoxicity. This study is focused on addressing the mutual relationship and early signals of these mechanisms in the D-galactosamine and lipopolysaccharide (D-GalN/LPS) hepatotoxicity model, with the help of standard liver function and biochemistry tests, histology, and measurement of gene expression by RT-PCR. Intraperitoneal injection of 400 mg/kg D-GalN and 50 μg/kg LPS was able to induce hepatotoxicity in rats, as evidenced by significant increases in liver enzymes (ALT, AST) and raised bilirubin levels in plasma. Heme oxygenase-1 and nitric oxide synthase-2 gene expressions were significantly increased, along with levels of their products, bilirubin and nitrite. The gene expression of glutathione peroxidase 1 remained unchanged, whereas a decrease in superoxide dismutase 1 gene expression was noted. Furthermore, the significant increase in the gene expression of apoptotic genes Bid, Bax and caspase-3 indicate early activation of apoptotic pathways, which was confirmed by histological evaluation. In contrast, the measured caspase-3 activity remained unchanged. Overall, the results have revealed differential oxidative stress and apoptotic responses, which deserves further investigations in this hepatotoxicity model.

Accelerating analysis for metabolomics, drugs and their metabolites in biological samples using multidimensional gas chromatography

Gas chromatography (GC) with mass spectrometry (MS) is one of the great enabling analytical tools available to the chemical and biochemical analyst for the measurement of volatile and semi-volatile compounds. From the analysis result, it is possible to assess progress in chemical reactions, to monitor environmental pollutants in a wide range of soil, water or air samples, to determine if an athlete or horse trainer has contravened doping laws, or if crude oil has migrated through subsurface rock to a reservoir. Each of these scenarios and samples has an associated implementation method for GC-MS. However, few samples and the associated interpretation of data is as complex or important as biochemical sample analysis for trace drugs or metabolites. Improving the analysis in both the GC and MS domains is a continual search for better separation, selectivity and sensitivity. Multidimensional methods are playing important roles in providing quality data to address the needs of analysts.

Plasma metabolic fingerprinting of childhood obesity by GC/MS in conjunction with multivariate statistical analysis

Metabolic fingerprinting is a powerful tool for exploring systemic metabolic perturbations and potential biomarkers, thus may shed light on the pathophysiological mechanism of diseases. In this work, a new strategy of metabolic fingerprinting was proposed to exploit the disturbances of metabolic patterns and biomarker candidates of childhood obesity. Plasma samples from children with normal weight, overweight and obesity were first profiled by GC/MS. ULDA (uncorrelated linear discriminant analysis) then revealed that the metabolic patterns of the three groups were different. Furthermore, several metabolites, say isoleucine, glyceric acid, serine, 2,3,4-trihydroxybutyric acid and phenylalanine were screened as potential biomarkers of childhood obesity by both ULDA and CCA (canonical correlation analysis). CCA also shows satisfactory correlation between the metabolic patterns and clinical parameters, and the results further suggest that WHR (waist-hip ratio) together with TG (total triglycerides), TC (total cholesterol), HDL (high density lipoprotein) and LDL (low density lipoprotein) were the most important parameters which are associated closely with the metabolic perturbations of childhood obesity, so as to be paid more attention for dealing with metabolic disturbances of childhood obesity in clinical practice rather than regularly monitored BMI (body-mass index). The results have demonstrated that the proposed metabolic fingerprinting approach may be a useful tool for discovering metabolic abnormalities and possible biomarkers for childhood obesity.

A novel scoring system for prognostic prediction in d-galactosamine/lipopolysaccharide-induced fulminant hepatic failure BALB/c mice

BACKGROUND

It is frequently important to identify the prognosis of fulminant hepatic failure (FHF) patients as this will influence patient management and candidacy for liver transplantation. Therefore, a novel scoring system based on metabonomics combining with multivariate logistic regression was developed to predict the prognosis of FHF mouse model.

METHODS

BALB/c mice were used to construct FHF model. Parts of plasma were collected at 4, 5, and 6-h time points after treatment, respectively, and detected using gas chromatography/time-of-flight mass spectrometry (GC/TOFMS). The acquired data were processed using partial least square discriminant analysis (PLS-DA). The metabolic markers identified were used to construct a scoring system by multivariate regression analysis.

RESULTS

28 mice of survival group and 28 of dead group were randomly selected and analyzed. PLS regression analysis showed that both the PLS models of 5 h and 6 h after d-galactosamine/lipopolysaccharide treatment demonstrated good performances. Loadings plot suggested that phosphate, beta-hydroxybutyrate (HB), urea, glucose and lactate concentrations in plasma had the highest weightings on the clustering differences at the three time points. By the multivariate logistic regression analysis, the death/survival index (DSI) was constructed based on relative concentrations of HB, urea and phosphate. It provided general accurate rate of prediction of 93.3% in the independent samples.

CONCLUSIONS

The novel scoring system based on metabonomics combining with multivariate logistic regression is accurate in predicting the prognosis of FHF mouse model and may be referred in clinical practice as a more useful prognostic tool with other available information.

Gas chromatography/mass spectrometry screening of serum metabolomic biomarkers in hepatitis B virus infected cirrhosis patients

BACKGROUND

Metabolomic studies have been applied to disease biomarkers selection. With the metabolomic technique, gas chromatography/mass spectrometry (GC/MS), human serum metabolites can be detected and identified. The purpose of this study was to investigate the serum metabolic profile of hepatitis B virus (HBV) infected cirrhosis patients and to detect disease biomarkers.

METHODS

HBV infected non-cirrhosis male subjects (n=20) and HBV infected cirrhosis male patients (n=20) participated in this experiment. Serum metabolome was detected through chemical derivatization followed by GC/MS. The high-flux metabolomic data were analyzed by stepwise discriminant analysis.

RESULTS

Out of the 41 metabolites detected in serum, we selected metabolites, including acetic acid, sorbitol, D-lactic acid, hexanoic acid, 1-naphthalenamine, butanoic acid, phosphoric acid, D-glucitol, and glucose, which in combination with each other could segregate the two groups. The error count was 0% for the non-cirrhosis group and 25% for the cirrhosis group.

CONCLUSIONS

This technique can be used to select biomarkers for hepatic cirrhosis.

An overview of animal models for investigating the pathogenesis and therapeutic strategies in acute hepatic failure

Acute hepatic failure (AHF) is a severe liver injury accompanied by hepatic encephalopathy which causes multiorgan failure with an extremely high mortality rate, even if intensive care is provided. Management of severe AHF continues to be one of the most challenging problems in clinical medicine. Liver transplantation has been shown to be the most effective therapy, but the procedure is limited by shortage of donor organs. Although a number of clinical trials testing different liver assist devices are under way, these systems alone have no significant effect on patient survival and are only regarded as a useful approach to bridge patients with AHF to liver transplantation. As a result, reproducible experimental animal models resembling the clinical conditions are still needed. The three main approaches used to create an animal model for AHF are: surgical procedures, toxic liver injury and infective procedures. Most common models are based on surgical techniques (total/partial hepatectomy, complete/transient devascularization) or the use of hepatotoxic drugs (acetaminophen, galactosamine, thioacetamide, and others), and very few satisfactory viral models are available. We have recently developed a viral model of AHF by means of the inoculation of rabbits with the virus of rabbit hemorrhagic disease. This model displays biochemical and histological characteristics, and clinical features that resemble those in human AHF. In the present article an overview is given of the most widely used animal models of AHF, and their main advantages and disadvantages are reviewed.

A metabolomic analysis of the toxicity of Aconitum sp. alkaloids in rats using gas chromatography/mass spectrometry

A metabolomic investigation of intoxication with Aconitum sp. alkaloids was carried out. Plasma obtained from Wistar rats administered these alkaloids was analyzed using gas chromatography/time-of-flight mass spectrometry. Samples were analyzed following protein precipitation, liquid-liquid extraction, and derivatization. Thirty-six metabolites were identified among the detected compounds. Subsequent data analysis using the t test and principal component analysis revealed metabolic differences between the control rats and treated groups as well as between the groups of rats administered different alkaloids. Twenty-seven metabolites were significantly different between plasma samples from the controls and treated groups. The significant decreased plasma levels of glutamine and creatinine in all treated groups suggested impaired heart and muscle function caused by alkaloids. The plasma levels of 22 metabolites in the hypaconitine group were significantly decreased. In contrast, only 8 and 13 metabolites were observed with significantly decreased levels in the aconitine and mesaconitine groups, respectively.These results indicated that Aconitum sp. alkaloids can cause metabolic disorders in rats. The toxicity and corresponding mechanism of hypaconitine was different from those of aconitine and mesaconitine, based on the differences of perturbed metabolic patterns between groups.

[Recent development of metabonomics and its applications in clinical research]

In the post-genomic era, systems biology is central to the biological sciences. Functional genomics such as transcriptomics and proteomics can simultaneous determine massive gene or protein expression changes following drug treatment or other intervention. However, these changes can't be coupled directly to changes in biological function. As a result, metabonomics and its many pseudonyms (metabolomics, metabolic profiling, etc.) have exploded onto the scientific scene in the past several years. Metabonomics is a rapidly growing research area and a system approach for comprehensive and quantitative analysis of the global metabolites in a biological matrix. Analytical chemistry approach is necessary for the development of comprehensive metabonomics investigations. Fundamentally, there are two types of metabonomics approaches: mass-spectrometry (MS) based and nuclear magnetic resonance (NMR) methodologies. Metabonomics measurements provide a wealth of data information and interpretation of these data relies mainly on chemometrics approaches to perform large-scale data analysis and data visualization, such as principal and independent component analysis, multidimensional scaling, a variety of clustering techniques, and discriminant function analysis, among many others. In this review, the recent development of analytical and statistical techniques used in metabonomics is summarized. Major applications of metabonomics relevant to clinical and preclinical study are then reviewed. The applications of metabonomics in study of liver diseases, cancers and other diseases have proved useful both as an experimental tool for pathogenesis mechanism re-search and ultimately a tool for diagnosis and monitoring treatment response of these diseases. Next, the applications of metabonomics in preclinical toxicology are discussed and the role that metabonomics might do in pharmaceutical research and development is explained with special reference to the aims and achievements of the Consortium for Metabonomic Toxicology (COMET), and the concept of pharmacometabonomics as a way of predicting an individual's response to treatment is highlighted. Finally, the role of metabonomics in elucidating the function of the unknown or novel enzyme is mentioned.

An integrated metabonomic method for profiling of metabolic changes in carbon tetrachloride induced rat urine

Carbon tetrachloride (CCl(4)) is a well-known model compound for inducing chemical hepatic injury. This work characterizes the metabolism disorders of hepatotoxicity induced by CCl(4) in a Wistar rat model with a single dosage of 1 ml/kg. A seven-day long continuous collection of urine was performed in male rats in this experiment. Blood biochemistry and histopathology were examined to identify specific changes of liver hepatotoxicity. At the same time, an integrated analytical approach based on liquid chromatography coupled with mass spectrometry (LC-MS) was developed to map the metabolic response in urine. The current metabonomic approach based on LC-MS indicated 23 endogenous metabolites as biomarkers in urine associated with the hepatotoxicity induced by CCl(4). The underlying regulations of CCl(4)-perturbed metabolic pathways were discussed according to the identified metabolites. The present study proves the great potential of LC-MS based metabonomics in mapping metabolic response for toxicology.

Dynamic metabonomic analysis of BALB/c mice with different outcomes after D-galactosamine/lipopolysaccharide-induced fulminant hepatic failure

Fulminant hepatic failure (FHF) is one of the most challenging gastrointestinal emergencies encountered in clinical practice. Early identification of patients with FHF who need liver transplantation is very important. To construct a prediction model for the early diagnosis and prognosis of FHF, we studied the dynamics of metabolic intermediates and metabolic profiles with a D-galactosamine (GalN)/lipopolysaccharide (LPS)-treated BALB/c mouse model of FHF. Levels of plasma metabolites were quantified with gas chromatography/time-of-flight mass spectrometry, and data were processed with partial least squares discriminant analysis (PLS-DA). Distinct clustering differences were observed 5 and 6 hours after GalN/LPS treatment between mice that survived and those that died, but there were no differences between these groups 4 hours after treatment. Five hours after treatment, plasma levels of some metabolites differed significantly between the survival, dead, and control groups. Ketogenesis and the tricarboxylic acid cycle were inhibited in both the survival and dead groups, but in the dead group, the urea cycle was also inhibited, and glycolysis was elevated. PLS-DA indicated that principal component weighting was greatest for plasma levels of phosphate, beta-hydroxybutyrate, urea, glucose, and lactate. The Y-predicted scatter plot in the partial least squares (PLS) model assigned samples to the survival or dead groups with an a priori cutoff of 0.10 with 100% sensitivity and specificity. Similar results were observed in 11 FHF patients with different outcomes. In conclusion, the PLS model based on metabonomic analysis can be used to predict outcomes well, and plasma levels of phosphate, beta-hydroxybutyrate, urea, glucose, and lactate may constitute a set of markers for the early diagnosis and prognosis of FHF.