Nuclear Magnetic Resonance-based Metabolomics Research Articles

Identification of metabolites associated with prostate cancer risk: a nested case-control study with long follow-up in the Northern Sweden Health and Disease Study

BackgroundProstate cancer is the second most frequently diagnosed cancer in men. Metabolomics can potentially provide new insights into the aetiology of prostate cancer by identifying new metabolic risk factors. This study investigated the prospective association between plasma metabolite concentrations and prostate cancer risk, both overall and by stratifying for disease aggressiveness and baseline age.MethodsIn a case-control study nested in the Northern Sweden Health and Disease Study, pre-diagnostic concentrations of 148 plasma metabolites were determined using targeted mass spectrometry- and nuclear magnetic resonance-based metabolomics in 777 prostate cancer cases (follow-up ≥ 5 years) and 777 matched controls. Associations between prostate cancer risk and metabolite concentrations were investigated using conditional logistic regression conditioned on matching factors (body mass index, age and sample storage time). Corrections for multiple testing were performed using false discovery rate (20%) and Bonferroni. Metabolomics analyses generated new hypotheses, which were investigated by leveraging food frequency questionnaires (FFQs) and oral glucose tolerance tests performed at baseline.ResultsAfter correcting for multiple testing, two lysophosphatidylcholines (LPCs) were positively associated with risk of overall prostate cancer (all ages and in older subjects). The strongest association was for LPC C17:0 in older subjects (OR = 2.08; 95% CI 1.45–2.98; p < 0.0001, significant also after the Bonferroni correction). Observed associations with risk of overall prostate cancer in younger subjects were positive for glycine and inverse for pyruvate. For aggressive prostate cancer, there were positive associations with six glycerophospholipids (LPC C17:0, LPC C20:3, LPC C20:4, PC ae C38:3, PC ae C38:4 and PC ae C40:2), while there was an inverse association with acylcarnitine C18:2. Moreover, plasma LPC C17:0 concentrations positively correlated with estimated dietary intake of fatty acid C17:0 from the FFQs. The associations between glycerophospholipids and prostate cancer were stronger in case-controls with normal glucose tolerance.ConclusionsSeveral glycerophospholipids were positively associated with risk of overall and aggressive prostate cancer. The strongest association was observed for LPC C17:0. The associations between glycerophospholipids and prostate cancer risk were stronger in case-controls with normal glucose tolerance, suggesting a link between the glucose metabolism status and risk of prostate cancer.

Metal pollution and its biological effects in swimming crab Portunus trituberculatus by NMR-based metabolomics

Metal pollution in the Bohai Sea in China has posed a potential risk on marine organisms. In this work, crabs (Portunus trituberculatus) were sampled from four sites, namely a reference (site 3934) and three metal-polluted (sites 6151, 6351, and 3562) sites, located in the Bohai Sea. Metal concentrations in crab gill tissues were measured using inductively coupled plasma mass spectrometry. Cu, Zn, and Cd in crab samples from S3562 presented the highest concentrations. Particularly, Cu concentration exceeded the marine biological quality standard II. Cd contents in crab samples from all metal-polluted sites exceeded the marine biological quality standard I. Nuclear magnetic resonance-based metabolomics indicated metal pollution-induced immune stresses in crab samples from all metal-polluted sites. Metal pollution in S6151 and S6351 disturbed energy metabolism through differential pathways. For crab samples from S3562, the metabolic profile suggested that metal pollution mainly induced osmotic stress.

Nuclear magnetic resonance-based metabolomics analysis and characteristics of beef in different fattening periods.

Beef quality is influenced by the fattening period. Therefore, meat metabolomics profiles from the different fattening periods (e.g., short-term vs. long-term) were analyzed for identify potential indicators using nuclear magnetic resonance. Additionally, blood, free fatty acid, sensory, and mineral compositions in Korean steers were determined. Blood, free fatty acid, and mineral concentrations showed significant differences between short-term and long-term groups that were fed different diets. However, there were no sensory differences in the two fattening groups. Additionally, the metabolic profiles of meats were clearly separated based on multivariate orthogonal partial least square discriminant analysis. Six metabolites of variable importance in the projection plot were identified and showed high sensitivity as candidate markers for meat characteristics. In particular, lactate, carnosine, and creatine could be directly linked to scientific indicators of the fattening stage (31 vs. 28 mo) of meat. Our findings suggest that the metabolomics approach could be a powerful method for the detection of novel signatures underlying the managing period of beef.

Physiochemical properties, protein and metabolite profiles of muscle exudate of chicken meat affected by wooden breast myopathy

The current study was designed to investigate the physiochemical properties, protein and metabolite profiles of muscle exudate obtained from chicken breast fillets affected by wooden breast (WB) myopathy. Twenty-four fillets were categorized into varying degrees of WB condition including normal, moderate and severe. Results indicated that exudate loss, free hemoglobin concentration, protein and lipid oxidation were affected by WB myopathy. Electrophoresis analysis showed eight distinct protein bands of differential relative abundance in WB samples compared with the normal, and the identified proteins were mostly involved in carbohydrate metabolic process. 1H nuclear magnetic resonance-based metabolomics identified eleven metabolites including amino acids, nucleotides and organic acid as the most influential metabolites affected by WB myopathy. Overall, this study shows differential molecular profiles of myopathic chicken muscle exudate, and provides a valuable resource for further recognition of WB myopathy.

1H NMR-Based Metabolic Profiles Delineate the Anticancer Effect of Vitamin C and Oxaliplatin on Hepatocellular Carcinoma Cells.

Hepatocellular carcinoma (HCC) is a leading cause of cancer death worldwide. Because of its high recurrence rate and heterogeneity, effective treatment for advanced stage of HCC is currently lacking. There are accumulating evidences showing the therapeutic potential of pharmacologic vitamin C (VC) on HCC. However, the metabolic basis underlying the anticancer property of VC remains to be elucidated. In this study, we used a high-resolution proton nuclear magnetic resonance-based metabolomics technique to assess the global metabolic changes in HCC cells following VC treatment. In addition, the HCC cells were also treated with oxaliplatin (OXA) to explore the potential synergistic effect induced by the combined VC and OXA treatment. The current metabolomics data suggested different mechanisms of OXA and VC in modulating cell growth and metabolism. In general, VC treatment led to inhibition of energy metabolism via NAD+ depletion and amino acid deprivation. On the other hand, OXA caused significant perturbation in phospholipid biosynthesis and phosphatidylcholine biosynthesis pathways. The current results highlighted glutathione metabolism, and pathways related to succinate and choline may play central roles in conferring the combined effect between OXA and VC. Taken together, this study provided metabolic evidence of VC and OXA in treating HCC and may contribute toward the potential application of combined VC and OXA as complementary HCC therapies.

Antibiotic Exposure Disturbs the Gut Microbiota and Its Metabolic Phenotype Differently in Rats with Advanced-Stage Type 1 Diabetes and Age-Matched Controls.

Antibiotic-induced microbial perturbations alter host metabolism and affect host physiology. In this study, we aimed to investigate the effects of vancomycin (Vanc) and ciprofloxacin/metronidazole (CiMe) exposures on the gut microbiome and metabolome in the colonic content and tissue samples from advanced-stage type 1 diabetic (AST1D) rats and age-matched controls (AMCs) using 16S ribosomal RNA gene sequencing and nuclear magnetic resonance-based metabolomics. The results show that antibiotic effects on the gut microbiota were stronger in AMC rats relative to AST1D rats. These microbial alterations were accompanied by a series of metabolic changes, including energy metabolism, short-chain fatty acid metabolism, and amino acid metabolism. We found that AMC rats had a more notable metabolic response to antibiotic exposure than AST1D rats. Additionally, Vanc had a stronger impact on the gut microbiota and host metabolic phenotype versus CiMe. Therefore, our results reveal that antibiotic-induced shifts in the gut microbiome and metabolome are different between AST1D and AMC rats. If confirmed in human studies, these findings suggest that diabetic patients may need a specific strategy for antibiotic use in clinical practice.

Associations of Aerobic Fitness and Maximal Muscular Strength With Metabolites in Young Men

High physical fitness is associated with a reduction in risk of cardiovascular diseases and death, but the underlying mechanisms are insufficiently understood. To determine how aerobic fitness and muscular strength are associated with serum metabolome measures. This cross-sectional study included Finnish men receiving military refresher training from May 5, 2015, to November 28, 2015, representing partly overlapping groups of individuals with the lowest vs highest aerobic fitness and the lowest vs highest muscular strength. Data analyses were conducted from January 1, 2018, to May 31, 2019. The associations of aerobic fitness (determined with maximum oxygen consumption in milliliters per minute per kilogram, measured with maximal cycle ergometer test) and muscular strength (determined with a maximal strength test for lower extremities in kilograms) with 66 metabolome measures from fasting serum samples (nuclear magnetic resonance-based metabolomics) were analyzed. Participants included 580 Finnish men (mean [SD] age, 26.1 [6.5] years). Including overlap between groups, there were 196 men in the lowest aerobic fitness group and 197 men in the highest aerobic fitness group as well as 196 men in the lowest muscular strength group and 197 men in the highest muscular strength group. Of 66 studied metabolome measures, 48 differed between high vs low aerobic fitness groups, including small very low-density lipoprotein (standardized median difference, -0.67; 95% CI, -0.83 to -0.49), large high-density lipoprotein (standardized median difference, 0.89; 95% CI, 0.69-1.15), total triglyceride levels (standardized median difference, -0.52; 95% CI, -0.65 to -0.34), isoleucine (standardized median difference, -0.37; 95% CI, -0.55 to -0.16), leucine (standardized median difference, -0.55; 95% CI, -0.72 to -0.34), phenylalanine (standardized median difference, -0.54; 95% CI, -0.71 to -0.32), glycerol (standardized median difference, -0.64; 95% CI, -0.81 to -0.48), and glycoprotein (standardized median difference, -0.78; 95% CI, -0.95 to -0.62) concentration, a high unsaturation degree of fatty acids (standardized median difference, 0.59; 95% CI, 0.42-0.81), and apolipoprotein B to apolipoprotein A1 ratio (standardized median difference, -0.88; 95% CI, -1.08 to -0.67). Adding aerobic fitness into the regression model after age, education, smoking, use of alcohol, and dietary factors accounted for more than an additional 5% of variation for 25 metabolome measures (R2 range, 5.01%-15.90% by measure). With these 2 criteria, maximal muscular strength was not associated with any metabolome measures. Aerobic fitness was associated with high large high-density lipoprotein particle concentration (R2, 14.97%; 95% CI, 10.65%-20.85%), low apolipoprotein B to apolipoprotein A1 ratio (R2, 14.49%; 95% CI, 10.58%-19.51%), and low glycoprotein concentration (R2, 15.90%; 95% CI, 11.22%-21.51%). Aerobic fitness was also associated with low very low-density lipoprotein, triglyceride, isoleucine, leucine, phenylalanine, glycerol, and glycoprotein concentrations and with a high unsaturation degree of fatty acids. Adjusting for recent physical activity influenced the results minimally. Adjusting for body fat percentage showed that some of the associations were mechanistically associated with body fat percentage. This study provides data on the association of high aerobic fitness with underlying oxidative lipid metabolism associated with a reduction in cardiometabolic risk. High maximal muscular strength is not similarly associated with these benefits.

Sanguinarine caused larval lethality and growth inhibition by suppressing energy metabolism in silkworms, Bombyx mori

Sanguinarine (Sang) is a natural alkaloid and distributed in several plants of Papaveraceae. The antitumor, antioxidant, antimicrobial and anti-inflammatory effects of Sang were extensively reported, but its speciality and mechanism against Lepidoptera insects were still unknown. In this study, detailed toxicological parameters of Sang against silkworms, Bombyx mori (B. mori), were determined by a toxicological test. Then, a nuclear magnetic resonance-based (NMR) metabolomics method was adopted to analyze the changes in hemolymph metabolites of silkworms after feeding Sang. The growth of fourth-instar larvae was significantly ceased by the oral administration of 0.05–0.3% Sang and vast deaths appeared in 0.3% Sang group on Day 4 and Day 5. The quantitative analysis of metabolites indicated that trehalose and citrate levels in hemolymph were increased after 24 h of feeding 0.3% Sang, whereas the concentrations of pyruvate, succinate, malate and fumarate were decreased. In addition, the enzymatic determination and reverse transcription quantitative PCR (RT-qPCR) showed that the trehalase (THL) activity and the transcriptional level of one gene coding THL were uniformly weakened by 0.3% Sang. One of the important mechanisms of Sang against silkworms might be interpreted as follows. Sang impaired trehalose hydrolysis, reduced THL activity and transcription, and led to the inhibition of energy metabolism, consequent antigrowth and high lethality in larvae of B. mori. Our findings offered new insights into the insecticidal effect of Sang from the perspective of energy metabolism and provided the basis for the application of Sang in the control of Lepidoptera pests.

Metabolic remodeling of cardiomyocytes identified in phosphoinositide-dependent kinase 1-deficient mice

Metabolic remodeling plays an essential role in the pathophysiology of heart failure (HF). Many studies have shown that the disruption of phosphoinositide-dependent protein kinase-1 (PDK1) caused severe and lethal HF; however, the metabolic pattern of PDK1 deletion remains ambiguous. 1H nuclear magnetic resonance-based metabolomics was applied to explore the altered metabolic pattern in Pdk1-deficient mice. Principle component analysis showed significant separation as early as 4 weeks of age, and dysfunction of metabolism precedes a morphological change in Pdk1-deficient mice. A time trajectory plot indicated that disturbed metabolic patterns were related to the pathological process of the HF in Pdk1-deficient mice, rather than the age of mice. Metabolic profiles demonstrated significantly increased levels of acetate, glutamate, glutamine, and O-phosphocholine in Pdk1 deletion mice. Levels of lactate, alanine, glycine, taurine, choline, fumarate, IMP, AMP, and ATP were significantly decreased compared with controls. Furthermore, PDK1 knockdown decreased the oxygen consumption rate in H9C2 cells as determined using a Seahorse XF96 Analyzer. These findings imply that the disruption of metabolism and impaired mitochondrial activity might be involved in the pathogenesis of HF with PDK1 deletion.

Nuclear magnetic resonance-based metabolomics and metabolic pathway networks from patient-matched esophageal carcinoma, adjacent noncancerous tissues and urine.

BACKGROUNDSeveral studies have demonstrated a correlation between esophageal cancer (EC) and perturbed urinary metabolomic profiles, but none has described the correlation between urine metabolite profiles and those of the tumor and adjacent esophageal mucosa in the same patient.AIMTo investigate how urinary metabolic phenotypes were linked to the changes in the biochemical landscape of esophageal tumors.METHODSNuclear magnetic resonance-based metabolomics were applied to esophageal tumor tissues and adjacent normal mucosal tissues alongside patient-matched urine samples.RESULTSAnalysis revealed that specific metabolite changes overlapped across both metrics, including glucose, glutamate, citrate, glycine, creatinine and taurine, indicating that the networks for metabolic pathway perturbations in EC, potentially involved in but not limited to disruption of fatty acid metabolism, glucose and glycolytic metabolism, tricarboxylic acid cycle and glutaminolysis. Additionally, changes in most urinary biomarkers correlated with changes in biomarker candidates in EC tissues, implying enhanced energy production for rapid cell proliferation.CONCLUSIONOverall, these associations provide evidence for distinct metabolic signatures and pathway disturbances between the tumor tissues and urine of EC patients, and changes in urinary metabolic signature could reflect reprogramming of the aforementioned metabolic pathways in EC tissues. Further investigation is needed to validate these initial findings using larger samples and to establish the underlying mechanism of EC progression.

Saliva NMR metabolomics: Analytical issues in pediatric oral health research.

Saliva metabolome is a promising diagnostic tool concerning oral and systemic diseases. We aimed at establishing a suitable protocol for saliva collection and gauging the relative impacts of gender, dentition stage, and caries on the saliva metabolome of a small children cohort. A nuclear magnetic resonance-based metabolomics cross-sectional study of children saliva (n=38) compared the effects of: (a) stimulation and unstimulation conditions, and (b) collection through passive drool and using an absorbing device. Multivariate and univariate statistical analyses were applied to evaluate such effects and those related to gender, dentition stage and caries. No significant differences were found between unstimulated and stimulated saliva, and the former was used for subsequent studies. Swab collection induced significant changes in sample composition, indicating passive drool as preferential. The impacts of gender and dentition stage were not significant compared to that of caries, which induced variations in the levels of 21 metabolites. These comprised amino acids and monosaccharides observed for the first time to our knowledge regarding children caries, suggesting protein hydrolysis and deglycosylation. Unstimulated passive drool saliva metabolome may carry a caries signature.

Identification of nitric oxide inhibitory compounds from the rhizome of Curcuma xanthorrhiza

Curcuma xanthorrhiza is a natural source of traditional medicines with numerous biological properties. This study profiles the metabolites in different fractions (hexane, chloroform, ethyl acetate and methanol) of the ethanolic extracts of C. xanthorrhiza using a nuclear magnetic resonance-based metabolomics approach. The nitric oxide (NO) inhibitory activity was determined using a Griess assay. The bioactivity and phytochemical constituents were correlated using partial least squares regression that indicated the differences between the 4 solvents based on the identified metabolites and their bioactivities. The results showed that the ethyl acetate fractions of C. xanthorrhiza had the highest NO inhibitory activity, this high activity is associated with the large quantity of curcuminoids found in this fraction. The metabolites that are responsible for the bioactivity are curcumin, demethoxycurcumin, l-hydroxy-1,7-bis(4-hydroxy-3-methoxyphenyl)-6-heptene-3,5-dione, and 1-(4-hydroxy-3,5-dimethoxyphenyl)-7-(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione. Ultra-performance liquid chromatography–tandem mass spectrometry was used to identify more metabolites in the active fraction, including bisdemethoxycurcumin and 1,7-bis(4-hydroxy-3-methoxyphenyl)-heptane-3,5-diol. The findings suggested that the ethyl acetate fraction of C. xanthorrhiza showed significant activity and can be a potential natural source of NO inhibitors.

Bioactive Compound Prodigiosin in Vivo Affecting the Nutrient Metabolism of Weaned Rats

Nuclear magnetic resonance-based metabolomics, intestinal microorganisms, and nutrient absorption were investigated to examine the effects of prodigiosin (PG) on the nutrient metabolism of weaned r...

Serum nuclear magnetic resonance-based metabolomics in patients with diffuse large B-cell lymphoma: a pilot study

Objective To discover new biomarkers for diffuse large B-cell lymphoma (DLBCL) diagnosis and prognosis using nuclear magnetic resonance (NMR)-based serum metabolomics. Methods High-resolution serum 1H NMR spectra were collected from 7 DLBCL patients and 7 healthy controls. Spectra were processed using stoichiometry pattern-recognition methods [principal component analysis (PCA) and orthogonal partial least squares discrimination analysis (OPLS-DA)]. Results Significant difference (P < 0.05) in 9 metabolites was observed between DLBCL and healthy control by OPLS-DA (variable interpretation rate R2Y = 99.0% and prediction rate Q2= 94.5%). Compared with the healthy control group, higher levels of lactate (r= 0.60, P < 0.01), glycine (r= 0.84, P < 0.001), creatine (r= 0.63, P < 0.01), and choline (r= 0.69, P < 0.01), lower levels of acetate (r=-0.88, P < 0.001), high-density lipoprotein (r=-0.77, P < 0.001), citrate (r=-0.82, P < 0.001), glutamine (r=-0.53, P < 0.05) and phosphocholine/glycerophosphocholine (r=-0.62, P < 0.001) were detected in the serum samples of DLBCL. Conclusion The results of this study offer an evidence for significant changes between DLBCL patients and healthy people in serum metabolite profiles utilizing NMR-based serum metabolomics. Key words: Lymphoma, large B-cell, diffuse; Metabolomics; Serum; Nuclear magnetic resonance, biomolecular

Nuclear magnetic resonance-based metabolomics approach to evaluate preventive and therapeutic effects of Gastrodia elata Blume on chronic atrophic gastritis

Chronic atrophic gastritis (CAG) is one of the most common digestive system diseases worldwide which defined by WHO as initial step of cancer. Gastrodia elata Blume (GEB) is a traditional herbal with multiple pharmacological activities which was widely used in Asian countries. This study aims to explore the preventive and therapeutical effects of Gastrodia elata Blume on auto-immune induced CAG in rats. Tissues of stomachs were collected and submitted to 1H NMR-based metabolomics analysis and histopathological inspection. The biochemical indexes of MDA, SOD, GSH, NO and XOD were measured. Gastrodia elata Blume could apparently ameliorate the damaged gastric glands and the biochemical parameters, enhance gastric acid secretion, and significantly relieve the inflammation of the stomach. Orthogonal signal correction-partial least squares-discriminant analysis (OSC-PLS-DA) of NMR profiles and correlation network analysis revealed that Gastrodia elata Blume could effectively treat CAG via regulating energy and purine metabolisms, and by anti-oxidation and anti-inflammation effects.

Biomonitoring of workers using nuclear magnetic resonance-based metabolomics of exhaled breath condensate: A pilot study

Exhaled breath condensate (EBC) is a non-invasive biological matrix that allows easy access to the lung epithelial lining fluid. It can provide, for instance, useful biochemical information in workers following inhalatory exposure. Recently, nuclear magnetic resonance (NMR)-based metabolomics has been applied to EBC profiling to identify metabolic phenotypes (“metabotypes”) of relevance in respiratory medicine.We aimed at verifying if NMR-based metabolomics of EBC, combined with statistical analysis, could find differences in metabolomic profiles between groups of subjects occupationally exposed to levels of airborne inhalable dust, phenol, formaldehyde and volatile organic compounds (VOCs) below regulatory limits.Samples were collected from 20 blue-collar workers without wearing a mask (therefore “exposed” to ambient air) and after wearing a mask (“not exposed”). This procedure was only allowed after the standard air quality tests had shown levels of airborne xenobiotics below the occupational exposure limit or even below the LOD. Ten white-collar controls were also included.After partial least squares discriminant analysis, the exposed to the controlled plant environment and the not exposed groups were clearly separated, and discrimination was due to alteration of fatty acids and alcohols, whose statistical significance was also evaluated.Our results show that NMR-based metabolomics of EBC is a useful tool that has the potential to be successfully used in occupational health to distinguish between subjects exposed and non-exposed to very low airborne levels of chemicals.

Analysis of salivary phenotypes of generalized aggressive and chronic periodontitis through nuclear magnetic resonance-based metabolomics.

Recent findings about the differential gene expression signature of periodontal lesions have raised the hypothesis of distinctive biological phenotypes expressed by generalized chronic periodontitis (GCP) and generalized aggressive periodontitis (GAgP) patients. Therefore, this cross-sectional investigation was planned, primarily, to determine the ability of nuclear magnetic resonance (NMR) spectroscopic analysis of unstimulated whole saliva to discriminate GCP and GAgP disease-specific metabolomic fingerprint and, secondarily, to assess potential metabolites discriminating periodontitis patients from periodontally healthy individuals (HI). NMR-metabolomics spectra were acquired from salivary samples of patients with a clinical diagnosis of GCP (n=33) or GAgP (n=28) and from HI (n=39). The clustering of HI, GCP, and GAgP patients was achieved by using a combination of the Principal Component Analysis and Canonical Correlation Analysis on the NMR profiles. These analyses revealed a significant predictive accuracy discriminating HI from GCP, and discriminating HI from GAgP patients (both 81%). In contrast, the GAgP and GCP saliva samples seem to belong to the same metabolic space (60% predictive accuracy). Significantly lower levels (P<0.05) of pyruvate, N-acetyl groups and lactate and higher levels (P<0.05) of proline, phenylalanine, and tyrosine were found in GCP and GAgP patients compared with HI. Within the limitations of this study, CGP and GAgP metabolomic profiles were not unequivocally discriminated through a NMR-based spectroscopic analysis of saliva.

Nuclear magnetic resonance-based metabolomics in respiratory medicine.

Footnotes This manuscript has recently been accepted for publication in the European Respiratory Journal . It is published here in its accepted …

Changes in serum metabolites in response to ingested colostrum and milk in neonatal calves, measured by nuclear magnetic resonance-based metabolomics analysis

Uptake of colostrum is of central importance for establishing a passive immunity transfer in neonatal calves. Studies of absorption and transmission of colostral immunoglobulins have been widely reported; however, changes in the serum in response to the absorption of colostral components in neonatal calves have not been completely characterized. Here, a nuclear magnetic resonance-based metabolomics approach was used to investigate the changes in metabolites in ingested colostrum, milk, and serum after neonatal calves were fed colostrum or milk. Twenty-seven neonatal male Holstein calves were assigned to 1 of the following groups: (1) calves not fed colostrum or milk and slaughtered approximately 2 h after birth (control group, n = 6), (2) calves fed colostrum at 1 to 2 h after birth and slaughtered 8 h after birth (n = 6), (3) calves fed 2 colostrum meals (at 1-2 and 10-12 h after birth) and slaughtered 24 h after birth (n = 6), (4) calves fed 3 colostrum meals (at 1-2, 10-12, and 22-24 h after birth) and slaughtered 36 h after birth (n = 6), or (5) calves fed 2 milk meals (1-2 and 10-12 h after birth) and slaughtered 24 h after birth (n = 3). Concentrations of valine, leucine, lactate, lysine, and isoleucine were higher and concentrations of lactose were lower in the groups fed colostrum and milk compared with groups not fed colostrum and milk, respectively. Metabolite changes between groups fed or not fed colostrum and milk were similar and may reflect the primary metabolic requirements of ingestion by the small intestine of neonatal calves. Concentrations of serum metabolites choline, valine, leucine, and glutamate were higher in the serum of calves that received colostrum compared with control calves. Furthermore, concentrations of serum phenylalanine, valine, and glutamate were significantly higher, whereas serum concentrations of citrate and very low density lipoproteins were lower in calves that received colostrum compared with calves fed milk. Our results indicate that concentrations of leucine, valine, and glutamate, which were higher in the calves that ingested colostrum, may transfer into the bloodstream, and that these metabolites are associated with health benefits in the neonatal calves that received colostrum. These findings provide novel information to help us understand the mechanism by which colostrum components are metabolized and absorbed in the small intestine and then transferred into bloodstream of neonatal calves.

NMR-based metabolic toxicity of low-level Hg exposure to earthworms

Mercury is a globally distributed toxicant to aquatic animals and mammals. However, the potential risks of environmental relevant mercury in terrestrial systems remain largely unclear. The metabolic profiles of the earthworm Eisenia fetida after exposure to soil contaminated with mercury at 0.77 ± 0.09 mg/kg for 2 weeks were investigated using a two-dimensional nuclear magnetic resonance-based (1H-13C NMR) metabolomics approach. The results revealed that traditional endpoints (e.g., mortality and weight loss) did not differ significantly after exposure. Although histological examination showed sub-lethal toxicity in the intestine as a result of soil ingestion, the underlying mechanisms were unclear. Metabolite profiles revealed significant decreases in glutamine and 2-hexyl-5-ethyl-3-furansulfonate in the exposed group and remarkable increases in glycine, alanine, glutamate, scyllo-inositol, t-methylhistidine and myo-inositol. More importantly, metabolic network analysis revealed that low mercury in the soil disrupted osmoregulation, amino acid and energy metabolisms in earthworms. A metabolic net link and schematic diagram of mercury-induced responses were proposed to predict earthworm responses after exposure to mercury at environmental relevant concentrations. These results improved the current understanding of the potential toxicity of low mercury in terrestrial systems.