Metabolites In Rat Serum Research Articles

Chinese herbal component, Praeruptorin E, enhances anti-asthma efficacy and prevents toxicity of aminophylline by targeting the NF-κB/PXR/CYP3A4 pathway

BackgroundAminophylline is widely used for the treatment of asthma, but the therapeutic dose is very close to the toxic dose, which makes this drug prone to accumulation poisoning. In the present study, we explored whether the Chinese herbal component, Praeruptorin E (PE), enhances anti-asthma efficacy and prevents the toxicity of aminophylline.MethodsFirst, an ovalbumin (OVA)-induced mouse model of asthma, immunohistochemistry, pathological staining, and bronchoalveolar lavage fluid (BALF) were used to detect the lung condition of asthmatic mice. The content of Th2 cytokines in serum was measured by enzyme-linked immunosorbent assay (ELISA), and the expression of related proteins was detected by Western blotting and immunofluorescence. Concentrations of theophylline and its metabolites in rat serum were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). siRNA transfection and chromatin immunoprecipitation (ChIP) were used to investigate the mechanism of PE.ResultsPE was found to synergize with aminophylline to reduce the infiltration of inflammatory cells, collagen deposition, and mucus hyperplasia in the lungs of asthmatic mice. It inhibited the expression of Th2 cytokines, interleukin (IL)-4, IL-5, and IL-13; promoted lung tissue repair; and reduced the toxic effect of aminophylline on the heart. Moreover, LC-MS/MS analysis showed that PE reduced the plasma concentration of the parent theophylline and its metabolite 1,3-dimethyluric acid (1,3-DMU). PE facilitated aminophylline’s suppression of nuclear factor-κB (NF-κB), and increased the expression of the xenobiotic nuclear receptor pregnane X receptor (PXR) and its primary target gene, CYP3A11 [this is the mouse homolog of cytochrome P450 3A (CYP3A)] in the asthmatic mouse liver and in the L-02 human fetal hepatocyte cell culture model. In addition, the ChIP assay revealed that PE attenuated the binding of NF-κB to the promoter region of the PXR gene and prevented the suppression of PXR gene expression by NF-κB.ConclusionsPE has a dual function in enhancing the immune regulation and anti-inflammatory effects of theophylline, as well as preventing theophylline toxicity by targeting the NF-κB/PXR/CYP3A4 axis. PE is a promising herbal medicine that will benefit asthmatics taking theophylline.

Tentative Identification of Etazene (Etodesnitazene) Metabolites in Rat Serum and Urine by Gas Chromatography-Mass Spectrometry and Accurate Mass Liquid Chromatography-Mass Spectrometry.

2-Benzylbenzimidazole derivatives comprise a small but forensically significant group of synthetic opioids. In humans, the metabolism of some members of this group is extensive, with little or none of the parent compound remaining. The recent detection of the 2-benzylbenzimidazole derivative, etazene (etodesnitazene), in products seized in Russia required the detection of its metabolites in biofluids for forensic toxicology purposes. Using gas chromatography--mass spectrometry (GC-MS) and high resolution accurate mass (HRAM) liquid chromatography-mass spectrometry (LC-MS), eight etazene metabolites were found in the urine and serum of rats. These were tentatively identified as products of N-deethylation, O-deethylation, hydroxylation or N-oxidation of benzimidazole moiety and combinations of these processes. The parent substance and its O-deethylated metabolite prevailed in rat serum, while in urine, the level of etazene was low compared to N,O-deethylated and N-deethylated with hydroxylation metabolites. Glucuronidated, sulfonated and glutathionated forms were not found. Taking into account reports on the study of the metabolism of other 2-benzylbenzimidazole derivatives in humans, it may be concluded that the mono-deethylated and mono-hydroxylated metabolites are suitable as target analytes in urine.

Systematically Explore the Absorbed Constituents and Metabolites in Rat Serum and Urine after Oral Administration and the Potential Mechanisms of <i>Anemarrhenae Rhizoma</i> Against T2DM by Serum Pharmacochemistry Combined with Network Pharmacology

Systematically Explore the Absorbed Constituents and Metabolites in Rat Serum and Urine after Oral Administration and the Potential Mechanisms of <i>Anemarrhenae Rhizoma</i> Against T2DM by Serum Pharmacochemistry Combined with Network Pharmacology

Identification and Analysis of Chemical Constituents and Rat Serum Metabolites in Gushuling Using UPLC-Q-TOF/MS Coupled with Novel Informatics UNIFI Platform

Gushuling (GSL), a well-known hospital preparation composed of traditional Chinese medicine (TCM), has been widely used in the clinical treatment of osteoporosis (OP) for decades due to its remarkable therapeutic effect. However, the chemical constituents of GSL are still unclear so far, which limits the in-depth study of its pharmacodynamic material basis and further restricts its clinical application. In this study, we developed a strategy for qualitative analysis of the chemical constituents of GSL in vitro and in vivo. Based on the results of ultra-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF-MS) and the UNIFI informatics platform, the chemical constituents of GSL can be determined quickly and effectively. By comparing the retention time, accurate mass, and fragmentation spectrum of the compounds in GSL, a total of 93 compounds were identified or preliminarily identified, including flavonoids, terpenoids, phenylpropanoids, steroids, etc. Among them, nine compounds have been confirmed by standard substances, namely epimedin A, epimedin B, epimedin C, icariin, ecdysterone, calycosin, calycosin-7-glucoside, ononin, and ginsenoside Ro. Fragment patterns and characteristic ions of representative compounds with different chemical structure types were analyzed. At the same time, 20 prototype compounds and 42 metabolites were detected in rat serum. Oxidation, hydration, reduction, dehydration, glutathione S-conjugation, and acetylcysteine conjugation were the main transformation reactions of GSL in rat serum. In this research, the rapid method to characterize the in vitro and in vivo chemical constituents of GSL can not only be used for the standardization and quality control of GSL but also be helpful for further research on its pharmacodynamic material basis.

Development of Simultaneous Determination Method of a Pregnan Steroid with Gestagenic Activity – Gestobutanoil and Two its Metabolites in Rat Serum

Introduction. Gestobutanoil is a synthetic pregnane steroid with gestagenic activity. Gestobutanoil has two pharmacologically active metabolites (AMOL and megestrol acetate). This implies the need for a detailed study of the kinetics of metabolites. It is rational to combine the study of the pharmacokinetics of gestobutanoil and its metabolites (AMOL and megestrol acetate). The simultaneous determination of several analytes in the rats’ serum can be carried out using chromatography-mass-spectrometry.Aim. Development of an analytical method for the simultaneous determination of gestobutanoil and two its metabolites in a biomatrix (rat serum).Materials and methods. The following methods were used to determine gestobutanoyl and two its metabolites in a biological matrix: GC-MS, HPLCESI-MS, HPLC-ESI-MS with derivatization, HPLC-APCI-MS.Results and discussion. When working with GC-MS, the chromatographic peaks of gestobutanoyl, AMOL, and megestrol acetate were strongly blurred and superimposed on each other, which is apparently due to the thermolability of the substances. The GC-MS method was abandoned in favor of HPLC. Analytes were separated by HPLC gradient elution on a C18 column. ESI ionization did not give typical protonated ions of gestobutanoyl and AMOL, and the intense signals of their cationized ions and fragment ions, which were observed in the spectra of AMOL and gestobutanoyl, could not ensure the reproducibility of the spectra, since the conditions of their formation are not suitable for routine analysis. Derivatization of analytes to form oximes and substituted hydrazones did not give the expected reaction products for HPLC-ESI-MS. APCI made it possible to remove intense cationized ions from the spectra of gestobutanoyl and AMOL and to increase the reliability of the method. The HPLCAPCI-MS technique was reproduced on model rat blood serum.Conclusion. An HPLC-MS method was developed for the simultaneous determination of gestobutanoyl, megestrol acetate, and AMOL. The technique was tested on a model rat blood serum containing all three analytes.

A metabolomic-based study on disturbance of bile acids metabolism induced by intratracheal instillation of nickel oxide nanoparticles in rats.

Nickel oxide nanoparticles (Nano NiO) evoke hepatotoxicity, while whether it affects the hepatic metabolism remains unclear. The aim of this study was to explore the differential metabolites and their metabolic pathways in rat serum and to further verify the potential mechanism of bile acids' (BAs) metabolism dysregulation after Nano NiO exposure. Sixteen male Wistar rats were intratracheally instilled with Nano NiO (0.24mg/kg body weight) twice a week for 9weeks. Liquid chromatography/mass spectrometry was applied to filter the differentially expressed metabolites in rat serum. Western blot was employed to detect the protein contents. Twenty-one differential metabolites that associated with BAs, lipid and phospholipid metabolism pathways were identified in rat serum after Nano NiO exposure. Decreased cholic acid and deoxycholic acid implied that the BAs metabolism was disturbed. The nickel content increased in liver after Nano NiO exposure. The protein expression of cholesterol 7α-hydroxylase (CYP7A1) was down-regulated, and the bile salt export pump was up-regulated after Nano NiO administration in rat liver. Moreover, dehydroepiandrosterone sulphotransferase (SULT2A1) and cytochrome P450 (CYP) 3A4 were elevated in the exposure group. In conclusion, Nano NiO might trigger the disturbances of BAs, lipid and phospholipid metabolism pathways in rats. The diminished serum BAs induced by Nano NiO might be related to the down-regulation of synthetase and to the overexpression of transmembrane protein and detoxification enzymes in BAs metabolism.

Integrative analysis of microbiome and metabolome in rats with Gest-Aid Plus Oral Liquid supplementation reveals mechanism of its healthcare function

Abstract Objective This study aimed to elucidate the possible mechanism of Gest-Aid Plus Oral Liquid (GAP) on healthcare function. Method Ultrahigh-performance liquid chromatography–quadrupole time-of-flight mass spectrometry-based metabolomics and 16S rDNA sequencing of gut microbiota were performed on serum and fecal samples of GAP and control rats. Additionally, short-chain fatty acids (SCFAs) and inflammatory cytokines in fecal samples were determined through gas chromatography–mass spectrometry and enzyme-linked immunosorbent assay kits. Result Metabolomics discovered 41 metabolites, which mainly involved amino acid metabolism, lipid metabolism, coenzyme factors, and vitamin metabolism. Administration of GAP increased abundance of Prevotella_9, Alloprevotella, Blautia, Phascolarctobacterium, Parabacteroides, and Fusicatenibacter, and six SCFAs were increased in the GAP group. Measurement of inflammatory cytokines showed that GAP had an anti-inflammatory effect in rats. Conclusion Administration of GAP greatly affects the aspartate metabolism and microecology of rats, enhances intestinal motility and gut barrier integrity and anti-inflammation. These findings not only have possible implications for further application of GAP, but also provide a link between the gut microbiome, SCFAs, inflammation and serum metabolites in rats.

A Combined Phytochemistry and Network Pharmacology Approach to Reveal the Effective Substances and Mechanisms of Wei-Fu-Chun Tablet in the Treatment of Precancerous Lesions of Gastric Cancer.

Wei-Fu-Chun (WFC) tablet is a commercial medicinal product approved by China Food and Drug Administration, which is made of Panax ginseng C.A.Mey., Citrus aurantium L., and Isodon amethystoides (Benth.). WFC has been popularly used for the treatment of precancerous lesions of gastric cancer (PLGC) in clinical practice. In this study, a UHPLC-ESI-Q-TOF/MS method in both positive and negative ion mode was employed to rapidly survey the major constituents of WFC. 178 compounds including diterpenoids, triterpenes, sesquiterpenes, flavonoids, saponins, phenylpropanoids, lignans, coumarins, organic acids, fatty acids, quinones, and sterols, were identified by comparing their retention times, accurate mass within 5 ppm error, and MS fragmentation ions. In addition, 77 absorbed parent molecules and nine metabolites in rat serum were rapidly characterized by UHPLC-ESI-Q-TOF/MS. The network pharmacology method was used to predict the active components, corresponding therapeutic targets, and related pathways of WFC in the treatment of PLGC. Based on the main compounds in WFC and their metabolites in rat plasma and existing databases, 13 active components, 48 therapeutic targets, and 61 pathways were found to treat PLGC. The results of PLGC experiment in rats showed that WFC could improve the weight of PLGC rats and the histopathological changes of gastric mucosa partly by inhibiting Mitogen-activated protein kinase (MAPK) signaling pathway to increase pepsin secretion. This study offers an applicable approach to identify chemical components, absorbed compounds, and metabolic compounds in WFC, and provides a method to explore bioactive ingredients and action mechanisms of WFC.

Rapid simultaneous determination of gut microbial phenylalanine, tyrosine, and tryptophan metabolites in rat serum, urine, and faeces using LC-MS/MS and its application to a type 2 diabetes mellitus study.

Gut microbial phenylalanine, tyrosine, and tryptophan metabolites are closely linked to various diseases. Monitoring the alterations of the related metabolites is vital to facilitate the understanding of pathophysiology of diseases. Herein, a rapid and sensitive assay based on LC-tandem mass spectrometry has been developed to analyze 20 gut microbial metabolites derived from phenylalanine, tyrosine, and tryptophan in rat serum, urine, and faeces. These microbial-derived metabolites were separated on a phenyl-hexyl column and simultaneously determined in a single run of 8 min. The detection limit for analytes ranged between 1.08 and 32.4 ng/mL. All calibration curves exhibited good linear relationships (R2 ≥ 0.9982). Intra- and inter-assay precision values were below 15% and accuracies ranged from 85% to 115% for all analytes. The selectivity, matrix effect, and recovery of this method were all satisfactory. The validated method was successfully applied to characterize the alterations of these metabolites in type 2 diabetes mellitus rat. In general, the developed assay is suitable for high-throughput monitoring of gut microbial phenylalanine, tyrosine, and tryptophan metabolites and provides a useful approach for exploring the mechanisms of microbial-derived metabolites in diseases.

Identification of metabolite biomarkers in serum of rats exposed to chlorpyrifos and cadmium

Chlorpyrifos (CPF) and cadmium (Cd) are widespread environmental pollutants, which are often present in drinking water and foods. However, the combined effects of CPF and Cd were not entirely clear at present. There was also no biomarker available to diagnose the poisoning of the two chemicals at low dose for long-term exposures. In this study, we investigated the change of serum metabolites of rats with subchronic exposure to CPF, Cd, and CPF plus Cd using gas chromatography-mass spectrometer-based metabolomics approach. We performed a stepwise optimization algorithm based on receiver operating characteristic to identify serum metabolite biomarkers for toxic diagnosis of the chemicals at different doses after 90-day exposure. We found that aminomalonic acid was the biomarker for the toxicity of Cd alone administration, and serine and propanoic acid were unique biomarkers for the toxicities of CPF plus Cd administrations. Our results suggest that subchronic exposure to CPF and Cd alone, or in combination at their low doses, could cause disturbance of energy and amino acid metabolism. Overall, we have shown that analysis of serum metabolomics can make exceptional contributions to the understanding of the toxic effects following long-term low-dose exposure of the organophosphorus pesticide and heavy metal.

Simultaneous quantitative determination of arachidonic acid and cascade metabolites in rat serum by UPLC-MS/MS: application for longitudinal metabolomics of anlotinib.

Arachidonic acid (AA) and cascade metabolites have been shown to be involved in cancer pathologic states. Anlotinib, a novel oral small molecule inhibitor of multiple receptor tyrosine kinases, has brought significant improvement to the survival of patients with advanced lung cancer. Here, a robust and reproducible ultrahigh performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed, optimized and validated for quantitating AA and cascade metabolites for the first time. Through careful optimization of the analytical conditions, a total of 69 analytes can be efficiently separated and quantitated in a single run of 17 min. A simple and labor-saving protein precipitation procedure was utilized for serum sample pretreatment. The validation parameters and quality control chart of all analytes satisfy the acceptance criteria of bioanalytical method guidelines. The limit of detection (LOD) ranged from 0.005 ng mL-1 to 1 ng mL-1, and the volume of serum was only 20 μL. This rapid and sensitive UPLC-MS/MS method was successfully applied to a longitudinal metabolomics study in rat serum after a single administration of anlotinib (6 mg kg-1). Finally, a total of 41 metabolites can be calculated under the present conditions. Serum samples from the same rat were segregated into a tight cluster in both unsupervised principal component analysis (PCA) and supervised orthogonal partial least-squares discriminant analysis (OPLS-DA) at different sampling time points after anlotinib treatment. Moreover, the number of analytes whose variable importance (VIP) values were larger than 1.0 was 17. The present study not only offers a UPLC-MS/MS analytical reference for AA but also brings out insights for future mechanistic studies or biomarkers to predict the efficacy, toxicity and clinical outcomes in patients with cancer.

Analysis of the chemical components of Qixianqingming granules and their metabolites in rats by UPLC-ESI-Q-TOF-MS.

Qixianqingming granules (QXQM) comprise a traditional Chinese medicine (TCM) formula that was developed based on the combination of TCM theory and clinical practice. This formula has been proven to effectively treat asthma. In this study, an analytical procedure using ultraperformance liquid chromatography, coupled with electrospray ionization quadrupole time-of-flight mass spectrometry, was established for the rapid separation and sensitive identification of the chemical components in QXQM and its metabolites in serum of rats. Seventy-two compounds were systematically identified in QXQM, including flavonoids, terpenoids, anthraquinones, phenylethanoid glycosides, stilbenes, alkaloids, and organic acids. Thirteen prototype compounds and 29 metabolites were detected in the serum of rats. The results provided fundamental information for further studying the mechanisms and clinical application of QXQM.

Mechanisms of Fuke Qianjin Capsules in treatment of pelvic inflammatory disease based on GC-MS metabolomics

Pelvic inflammatory disease( PID) rat model was induced by the mixture of Escherichia coli,Staphylococcus aureus,and Streptococcus hemolytic-β． Gas chromatography-mass spectrometry( GC-MS) based metabolic profiling method was combined with multivariate statistical analysis,such as PCA,PLS-DA and OPLS-DA to analyze endogenous small molecule metabolites in serum of rats after treatment of Fuke Qianjin Capsules. The results showed that Fuke Qianjin Capsules could significantly improve the inflammatory pathological characteristics and tissue damages in model rats. Based on the principle of VIP>1 and P<0. 05,a total of 6 different metabolic biomarkers were identified,including L-valine,L-isoleucine,L-threonine,butanedioic acid,serine and D-glucose,respectively.The contents of these six different metabolites were significantly reversed after administration. Further analysis of the metabolite pathways through KEGG database showed that Fuke Qianjin Capsules achieved the effect possibly through glycine,serine and threonine metabolism,aminoacyl-tRNA biosynthesis and valine,leucine and isoleucine biosynthesis. Therefore,this study came to the conclusion that Fuke Qianjin Capsules can be used in the treatment of mixed bacteria induced pelvic inflammatory disease possibly by regulating amino acid and its derivative metabolism.

UPLC-Q-TOF/MS characterization of efficacy substances on osteoblasts differentiation and function in rat serum after administration of Wang-Bi tablet.

Wang-Bi tablet (WB) is popularly used for the treatment of rheumatoid arthritis. However, few studies have been carried out on its active ingredients and mechanism. In this study, the effect of WB medicated serum on the changes in differentiation and function in osteoblast was investigated, the results showed that WB induced the production of ALP and mineralized nodules to promote the final maturation of osteoblasts and enhance the function of osteoblasts. The potential mechanism may that WB significantly inhibits gene expressions of RANKL and miR-141, up-regulates the gene expressions of RUNX2 and OPG, decreases expression of DKK-1 and increases levels of β-catenin protein to promote the activation of Wnt/β-catenin signaling pathways, which enhances osteogenesis and bone repair function. To investigate which compounds contributed to the activity and mechanisms, a total of 138 compounds were characterized from WB, and 13 parent molecules and eight metabolites in rat serum were rapidly characterized by UPLC-Q-TOF/MS. Total glycosides of paeony, loganin, α-linolenic acid, linoleic acid and naringin from WB may contribute to the actions on osteoblasts according to our study and literature review. Our research provides a method to explore the bioactive ingredients and action mechanisms of WB.

Identification and structural characterization of febuxostat metabolites in rat serum and urine samples using UHPLC-QTOF/MS.

Febuxostat is a novel nonpurine type of highly selective xanthine oxidoreductase inhibitor. A rapid and sensitive ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry method for simultaneous separation and determination of febuxostat and its metabolites in rat serum and urine was developed at various time points after oral administration to the rats. The febuxostat metabolites were predicted by biotransformation software and transformed to a personal compound database to quickly determine the possible metabolites from the MS1 data. The possibility of the MS/MS fragmentation was calculated by the Molecular Structure Correlator software. As a result, five phase I and two phase II metabolites in rat serum, and seven phase I and three phase II metabolites in rat urine were identified, of which four metabolites (M2, M5, M6, M7) have not been reported before. The metabolite toxicities are predicted, and the results are helpful for the design of new xanthine oxidoreductase inhibitors.

Rapid discovery of chemical constituents and absorbed components in rat serum after oral administration of Fuzi-Lizhong pill based on high-throughput HPLC-Q-TOF/MS analysis

BackgroundFuzi-Lizhong pill (FZLZP), which was first recorded in the Classic–“Taiping Huimin Heji Ju Fang” of the Song Dynasty, has been widely used to treat gastrointestinal disease in clinic for thousands of years in China. However, an in-depth understanding of the chemical constituents of FZLZP and its potential bioactive constituents is lacking.MethodsA simple, sensitive and selective method of high-performance liquid chromatography coupled with quadrupole-time-of-flight high-definition mass spectrometry (HPLC-Q-TOF/MS) and automated data analysis (Agilent MassHunter Qualitative Analysis B.06.00 Workstation Software) was developed to simultaneously identify the chemical constituents of FZLZP and the absorbed prototypes as well as the metabolites in rat serum after the oral administration of FZLZP.ResultsSixty-seven compounds, including alkaloids, flavonoids, triterpenes, gingerols, phenylpropanoids and volatile oil, in the FZLZP extract were tentatively characterized by comparing the retention time and mass spectrometry data and retrieving the reference literatures. Additionally, 23 prototype compounds and 3 metabolites in the rat serum samples were identified after oral administration of FZLZP, which might be the potential active components in vivo. In addition, the absorption of alkaloids decreased when Aconitum carmichaeli Debx. was in the form of combined application as a prescription compared to when it was in the form of herb powder.ConclusionsHerein, the chemical constituent in vitro and the absorbed compounds in the serum of a traditional Chinese formula, Fuzi-Lizhong pill, were fully characterized using a rapid and comprehensive analysis approach based on high-performance liquid chromatography combined with quadrupole time-of-flight mass spectrometry coupled to MassHunter Qualitative Analysis software data processing approach. The results provide helpful chemical information on FZLZP for further pharmacology and active mechanism research. In view of the bioactive constitutes that basically were derived from these absorbed compounds in vivo, this work could provide a useful strategy to explore the bioactive substances of traditional Chinese medicine.

Identification of potential metabolic biomarkers in Yin deficiency syndrome using LC-MS.

Yin and Yang are the two counter-balancing aspects in ancient Chinese philosophy. In traditional Chinese medicine, Yin deficiency syndrome (YDS) is a common sub-health state with complex causes. While the syndrome may be treated to various degrees of effectiveness with traditional Chinese medicine, efficient modern methods are yet to be developed for diagnosing and treating the YDS. Here we performed a metabolomics study on YDS in rats. Serum metabolites in rats were analyzed using ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) method to identify potential biomarkers for YDS. The rats were divided randomly into the healthy control group, the untreated YDS group, and the anemarrhena treated YDS group. Compared with the control group, significant increase in the metabolites such as dihydrotestosterone (DHT) and 5β-DHT, 4-imidazolone-5-propanoate, 4-(L-alanin-3-yl)-2-hydroxy-cis,cis-muconate 6-semialdehyde, and 5-(L-alanin-3-yl)-2-hydroxy-cis,cis-muconate 6-semialdehyde were observed in the serum of untreated YDS group, which returned to normal in the anemarrhena treated group. Therefore, these metabolites may serve as potential biomarkers for YDS, and may facilitate the diagnosis and treatment of YDS.

A Study of NMR-Based Hepatic and Serum Metabolomics in a Liver Injury Sprague-Dawley Rat Model Induced by Psoralen.

Psoralen is the main active component of Psoralea corylifolia and is used as a marker to assess its quality. The effects of psoralen on animals have been well characterized. However, the molecular pathway of its toxicity is not fully understood. In this study, the toxic effects of psoralen administration (60 mg/kg) for 7 days in Sprague-Dawley rats were observed. Serum biochemistry and liver histopathology were further investigated. Proton nuclear magnetic resonance was applied to characterize the metabolic profile of liver toxicity induced by psoralen and to find changed metabolites in rat serum and liver. It was revealed that visceral coefficients and serum biochemistry indexes were significantly changed in rats with psoralen-induced liver injury. Furthermore, the histopathological examination exhibited that the liver might be the target organ for psoralen. Metabolic analysis of both serum and liver samples further proved the liver was the target of toxicity of psoralen. Multivariate analysis identified 7 metabolites in serum samples and 15 in liver samples as potential biomarkers in liver injury induced by psoralen. In addition, our results suggest that psoralen can cause a disturbance in amino acid metabolism, especially valine, leucine, and isoleucine biosynthesis in both serum and liver samples. In conclusion, we combined the results of toxicity and metabolomics induced by psoralen and provide useful information about the safety and potential risks of psoralen and Psoralea corylifolia.

Altered Serum Metabolite Profiling and Relevant Pathway Analysis in Rats Stimulated by Honeybee Venom: New Insight into Allergy to Honeybee Venom.

To improve our understanding of the disturbed metabolic pathways and cellular responses triggered by honeybee venom stimulation, we compared the changes in serum metabolites in rats, either stimulated or not by honeybee venom, by performing 1H nuclear magnetic resonance (NMR) spectrometry-based metabonomics to identify potential biomarkers. In this study, 65 metabolites were structurally confirmed and quantified and the following results were obtained. First, by pattern recognition analysis, 14 metabolites were selected as potential biomarkers 3 h after venom stimulation. Second, metabolic pathway analysis showed that methane metabolism, glyoxylate and dicarboxylate metabolism, tricarboxylic acid cycle, glycine, serine, and threonine metabolism, arginine and proline metabolism were affected. Finally, the time-dependent metabolic modifications indicated that rats could recover without medical treatment 24 h after venom stimulation. In summary, this new insight into the changes in serum metabolites in rats after honeybee venom stimulation has enhanced our understanding of the response of an organism to honeybee venom.

Impact of conjugated linoleic acid administered to rats prior and after carcinogenic agent on arachidonic and linoleic acid metabolites in serum and tumors

The objective of the study was to assess the influence of conjugated linoleic acid (CLA) daily supplementation prior and after carcinogenic agent on the concentrations of eicosanoids – metabolites of arachidonic acid (15-, 12- or 5-hydroxyeicosatetraenoic acids (15-, 12-, 5-HETE), prostaglandin E2 (PGE2)) and linoleic acid (13- or 9-hydroxyoctadecadienoic acids (13-, 9-HODE)) in rat serum and 7,12-dimethylbenz[a]anthracene (DMBA)-induced tumors. Female rats were randomised into six groups, receiving 1% or 2% Bio-C.L.A or plant oil since the 37th day of life throughout the whole experiment. Some rats (50-day-old) were administered DMBA to induce tumors. Eicosanoids were analyzed with LC-MS/MS. The study indicated that CLA supplemented daily to rats prior and after carcinogen administration affected concentrations of arachidonic and linoleic acid metabolites in rat serum and induced tumors. However, ratios of eicosanoids exerting opposite activities (e.g. 12-HETE/15-HETE) appear to act as more precise factors reflecting pathological changes in an organism than individual compounds.