GC-TOF-MS-based serum metabolomic investigations of naked oat bran supplementation in high-fat-diet-induced dyslipidemic rats

A metabolomics perspective reveals the mechanism of the uric acid-lowering effect of Prunus salicina Lindl. cv. "furong" polyphenols in hypoxanthine and potassium oxybate-induced hyperuricemic mice

The incidence of hyperuricemia (HUA) shows a gradually increasing trend towards affecting younger individuals, and it can significantly harm the overall health status of the body. Based on a metabolomics perspective, this study reveals the mechanism of the uric acid-lowering action of Prunus salicina Lindl. cv. "furong" polyphenols (PSLP) on a hyperuricemia mouse model induced by hypoxanthine and potassium oxybutyrate. The results demonstrate that PSLP comprise an effective treatment strategy for reducing the levels of serum uric acid (SUA), serum creatinine (SCr) and blood urea nitrogen (BUN) in HUA mice (p < 0.05), wherein the maximum decrease rates are up to 44.50%, 29.46%, and 32.95%, respectively. PSLP are observed to exert a pronounced inhibitory effect on the activities of xanthine oxidase (XOD) and adenosine deaminase (ADA) in the livers of HUA mice, with reductions of up to 16.36% and 20.13%, respectively. These findings illustrate that PSLP exert a significant uric acid-lowering effect. Subsequent metabolomic analysis of mouse serum identified 28 potential biomarkers for hyperuricemia, whose levels were markedly diminished by PSLP. This process involved alterations in purine, glycine, the pentose phosphate pathway, and galactose metabolism. Twenty-eight potential biomarkers were identified for hyperuricemia by subsequent metabolomic analysis of mouse serum, whose levels were markedly reversed by PSLP intervention. The regulation of HUA by PSLP involved alterations in purine metabolism, glycerolipid metabolism, the pentose phosphate pathway, and galactose metabolism. The mechanism of PSLP ameliorated hyperuricemia might be attributed to reduction of the level of the uric acid precursor ribose-5-phosphate in the pentose phosphate pathway, the inhibition of the activities of uric acid synthase XOD and ADA in purine metabolism, and reduction of the synthesis of the end product uric acid. This study provides a theoretical basis for the development of functional foods based on PSLP, which can potentially reduce uric acid levels.

Urine and Dried Blood Spots From Children and Pregnant Women Reveal Phytochemicals, Amino Acids, and Carnitine Metabolites as Cowpea Consumption Biomarkers

SCOPE

Legumes consumption has been proven to promote health across the lifespan; cowpeas have demonstrated efficacy in combating childhood malnutrition and growth faltering, with an estimated malnutrition prevalence of 35.6% of children in Ghana. This cowpea feeding study aimed to identify a suite of metabolic consumption biomarkers in children and adults.

METHODS AND RESULTS

Urine and dried blood spots (DBS) from 24 children (9-21 months) and 21 pregnant women (>18 years) in Northern Ghana are collected before and after dose-escalated consumption of four cowpea varieties for 15 days. Untargeted metabolomics identified significant increases in amino acids, phytochemicals, and lipids. The carnitine metabolism pathway is represented by 137 urine and 43 DBS metabolites, with significant changes to tiglylcarnitine and acetylcarnitine. Additional noteworthy candidate biomarkers are mansouramycin C, N-acetylalliin, proline betaine, N2, N5-diacetylornithine, S-methylcysteine, S-methylcysteine sulfoxide, and cis-urocanate. S-methylcysteine and S-methylcysteine sulfoxide are targeted and quantified in urine.

CONCLUSION

This feeding study for cowpea biomarkers supports the utility of a suite of key metabolites classified as amino acids, lipids, and phytochemicals for dietary legume and cowpea-specific food exposures of global health importance.

Oat bran prevents high-fat-diet induced muscular dysfunction, systemic inflammation and oxidative stress through reconstructing gut microbiome and circulating metabolome

Western-type diet characterized by high fat emerges a promoter of skeletal muscle dysfunctions. Oat bran was typically considered a healthy food of premium quality for its abundant dietary fiber. The present study comprehensively explored the effects of a diet rich in oat bran on skeletal muscle disfunctions in high-fat diet (HFD) fed mice. Dietary-fiber-rich oat bran significantly ameliorated HFD-induced skeletal muscle function abnormalities, as evidenced by a phenotype improvement in mice grip strength and endurance treadmill running distance, accompanied with the regulation of muscle functions related gene expressions, namely Fis1, Cytc, Mhy2 and Mhy4. Oat bran suppressed the production of systemic inflammatory cytokines while promoted superoxide dismutase and glutathione. Furthermore, oat bran significantly impacted gut microbiota composition by promoting short chain fatty acids (SCFAs) producers and certain probiotic genera, along with the enhancement of SCFAs. Oat bran also significantly decreased the circulating levels of inflammation-related metabolites and played roles in MAPK signaling, thereafter influencing skeletal muscle functions. Collectively, benefits from integration of biomedical indicators, microbiomics, and metabolomics demonstrates the benefits of oat bran consumption on prevention of HFD-related muscular dysfunctions via alleviating HFD-induced inflammation, gut dysbiosis, and systemic metabolism, pinpointing a novel mechanism underlying the muscle-promoting property of oat bran.

Novel application potential of cinaciguat in the treatment of mixed hyperlipidemia through targeting PTL/NPC1L1 and alleviating intestinal microbiota dysbiosis and metabolic disorders

Mixed hyperlipidemia, characterized by high levels of triglycerides and cholesterol, is a key risk factor leading to atherosclerosis and other cardiovascular diseases. Existing clinical drugs usually only work on a single indicator, decreasing either triglyceride or cholesterol levels. Developing dual-acting agents that reduce both triglycerides and cholesterol remains a great challenge. Pancreatic triglyceride lipase (PTL) and Niemann-Pick C1-like 1 (NPC1L1) have been identified as crucial proteins in the transport of triglycerides and cholesterol. Here, cinaciguat, a known agent used in the treatment of acute decompensated heart failure, was identified as a potent dual inhibitor targeting PTL and NPC1L1. We presented in vitro evidence from surface plasmon resonance analysis that cinaciguat interacted with PTL and NPC1L1. Furthermore, cinaciguat exhibited potent PTL-inhibition activity. Fluorescence-labeled cholesterol uptake analysis and confocal imaging showed that cinaciguat effectively inhibited cholesterol uptake. In vivo evaluation showed that cinaciguat significantly reduced the plasma levels of triglycerides and cholesterol, and effectively alleviated high-fat diet-induced intestinal microbiota dysbiosis and metabolic disorders. These results collectively suggest that cinaciguat has the potential to be further developed for the therapy of mixed hyperlipidemia.

Pharmacometabolomics for the Study of Lipid-Lowering Therapies: Opportunities and Challenges

Lipid-lowering therapies are widely used to prevent the development of atherosclerotic cardiovascular disease (ASCVD) and related mortality worldwide. "Omics" technologies have been successfully applied in recent decades to investigate the mechanisms of action of these drugs, their pleiotropic effects, and their side effects, aiming to identify novel targets for future personalized medicine with an improvement of the efficacy and safety associated with the treatment. Pharmacometabolomics is a branch of metabolomics that is focused on the study of drug effects on metabolic pathways that are implicated in the variation of response to the treatment considering also the influences from a specific disease, environment, and concomitant pharmacological therapies. In this review, we summarized the most significant metabolomic studies on the effects of lipid-lowering therapies, including the most commonly used statins and fibrates to novel drugs or nutraceutical approaches. The integration of pharmacometabolomics data with the information obtained from the other "omics" approaches could help in the comprehension of the biological mechanisms underlying the use of lipid-lowering drugs in view of defining a precision medicine to improve the efficacy and reduce the side effects associated with the treatment.

Oat β Glucan Ameliorates Renal Function and Gut Microbiota in Diabetic Rats

Diabetic nephropathy is a severe complication of diabetes and the leading cause of end-stage renal disease and death. Therefore, we must find effective prevention and treatment approaches to the problem. Oat has a long history of use for its nutritional and medicinal properties, such as maintaining physiological blood glucose levels. Oat β glucan is one of the major bioactive substances produced by oat. However, the protective effects of oat β glucan on diabetic nephropathy are still unclear. This study generated a rat model of diabetic nephropathy to explore the potent therapeutic ability and mechanism of oat β glucan in renal function by 16S rRNA genes sequencing. Diabetic nephropathy model was established in forty rats by left nephrectomy and single intraperitoneal injection of streptozotocin. These rats were randomly divided into the model group and three oat β glucan intervention groups. Twenty rats underwent sham operation and were randomly divided into normal control group and oat β glucan control group. Animals were treated by oral gavage for 8 consecutive weeks. The results showed that oat β glucan reduced blood glucose level and improved renal function (P &lt; 0.05). Oat β glucan significantly improved serum inflammatory levels (P &lt; 0.05). The diversity of intestinal microflora in diabetic nephropathy rats decreased with time prolongation, while oat β-glucan reversed the result. Compared with the model group at week 8, the abundances of Eubacterium, Butyricicoccus, and Ruminococcus were elevated significantly after oat β glucan intervention (P &lt; 0.05). Correlation analysis indicated that abundances of Eubacterium, Butyricicoccus, and Ruminococcus were significantly negatively correlated with the levels of renal impairment markers. In summary, the findings of this study showed that oat β glucan can increase the diversity of intestinal flora, regulate the composition of intestinal flora, modulate intestinal flora metabolism, alleviate the inflammatory response, and further delay the development of diabetic nephropathy. Therefore, oat β glucan has the potential to be developed into the novel and safe drug for diabetic nephropathy.

Targeted metabolomic analysis of plasma fatty acids in acute myocardial infarction in young adults

BACKGROUND AND AIMS

Acute myocardial infarction (AMI) in young adults has distinct clinical features and risk profile as compared with that in elder adults. The pathophysiologic mechanism of AMI in young adults remains unclear. In this study, we used targeted metabolomics to measure metabolic profile and analyzed plasma fatty acids levels in young adults with AMI, seeking to determine whether circulating fatty acid metabolism was correlated with the occurrence of AMI in young adults.

METHODS AND RESULTS

Consecutive young and elder patients admitted to hospital for AMI were enrolled. Plasma samples of all participants were obtained after overnight fast and then measured using ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS) based targeted metabolomic platform. A total of 201 plasma metabolites were measured using UPLC-MS/MS. Several plasma fatty acids were significantly altered in young AMI patients compared with control or elder AMI patients, which also showed significant prediction value for AMI in young adults. Percentage of short chain fatty acids (SCFAs) was decreased and long chain increased in AMI as compared with control. Moreover, alpha-linolenic acid and linoleic acid metabolism (ALALAM) pathway metabolites were gradually increased in control, young, and elder AMI patients. Altered fatty acid correlation network further identified fatty acid metabolism disorder in AMI in young adults.

CONCLUSION

By utilizing targeted metabolomic technique, we have found several altered fatty acids and respective pathways that show diagnostic value for AMI in young adults. SCFA and long-chain fatty acid (LCFA) were differentially altered in AMI patients.

Polyphenols and avenanthramides extracted from oat (Avena sativa L.) grains and sprouts modulate genes involved in glucose and lipid metabolisms in 3T3 L1 adipocytes

This study aimed to evaluate the effect of polyphenol (PE) and avenanthramide (AE) extracts from oat grains (OG) and sprouts (OS) on genes related to glucose and lipid metabolisms in 3T3 L1 adipocytes. The AE-OS exerted the greatest effect on genes involved in glucose metabolism, increasing Glut4, Irs1, and Pi3k expression by 3.0- to 3.9-fold. Conversely, the PE-OS exerted the greatest effect on genes involved in lipid metabolism, decreasing Fasn and Acaca expression by 0.2- to 0.3-fold, and increasing Cpt1a and Acadm expression by 2.7- to 3.0-fold. These effects were mainly related to their high content of avenanthramides A (2p), B (2f), and C (2c), quercetin 3-O-rutinoside, kaempferol, sinapoylquinic acid, and apigenin and luteolin derivatives according to the chemometric analysis. In conclusion, this study demonstrated that oat sprouts extract exerts a greater effect than oat grains on the regulation of genes involved in glucose and lipid metabolisms in adipocytes. PRACTICAL APPLICATIONS: This study demonstrates that polyphenols and avenanthramides extracted from oat (Avena sativa L.) grains and sprouts modulate key genes involved in glucose and lipid metabolisms in adipocytes and that oat sprouts exert a greatest health beneficial effect than oat grains due to their higher content of bioactive compounds. In addition, the chemometric analysis identified the bioactive compounds that can be associated with the beneficial effects of oat grains and sprouts, which can be further used for the identification of oat varieties and oat-derived products with high content of these bioactive compounds and, thus, with high nutraceutical potential.

Serum Metabolomics Reveals Underlying Mechanisms of Cholesterol-Lowering Effects of Oat Consumption: A Randomized Controlled Trial in a Mildly Hypercholesterolemic Population

INTRODUCTION

The purpose of this study is to examine the effects of oat supplementation on serum lipid in a population of adults with mild hypercholesterolemia and reveal the underlying mechanisms with serum untargeted metabolomics.

METHODS AND RESULTS

In this placebo-controlled trial, 62 participants from Nanjing, China, with mild elevations in cholesterol are randomly assigned to receive 80 g oats (containing 3 g beta-glucan) or rice daily for 45 days. Fasting blood samples are collected at the beginning, middle, and end of the trial. Compared with the rice group, oat consumption significantly decreases serum total cholesterol (TC) (-8.41%, p = 0.005), low-density lipoprotein cholesterol (LDL-c) (-13.93%, p = 0.001), and non high-density lipoprotein cholesterol (non-HDL-c) (-10.93%, p = 0.017) levels. There are no significant between-group differences in serum triglyceride (TG), apolipoprotein B (Apo B), glycated albumin, or fasting blood glucose levels. An orthogonal partial least squares discriminant analysis (OPLS-DA) suggests a clear separation in metabolic profiles between the groups after the intervention. Twenty-one metabolites in the oat group are significantly different from those in the rice group, among which 14 metabolites show a decreased trend. In comparison, seven metabolites show an increased trend. Correlations analysis from both groups indicate that most metabolites [e.g., sphinganine and phosphatidylcholine (PC)(20:5(5Z,8Z,11Z,14Z,17Z)/20:1(11Z))] have positive correlations with serum cholesterol levels. Kyoto Encyclopedia of Gene and Genomes pathway analysis suggests that oat consumption regulated glycerophospholipid, alanine, aspartate and glutamate, sphingolipid, and retinol metabolism.

CONCLUSION

Oat consumption has beneficial effects on serum lipids profiles. The underlying mechanisms involve glycerophospholipid, alanine, aspartate and glutamate, sphingolipid, and retinol metabolism in adults.

Serum Metabolomic Profiling to Reveal Potential Biomarkers for the Diagnosis of Fatty Liver Hemorrhagic Syndrome in Laying Hens

Fatty liver hemorrhage syndrome (FLHS), a nutritional and metabolic disease that frequently occurs in laying hens, causes serious losses to the poultry industry. Nowadays, the traditional clinical diagnosis of FLHS still has its limitations. Therefore, searching for some metabolic biomarkers and elucidating the metabolic pathway in vivo are useful for the diagnosis and prevention of FLHS. In the present study, a model of FLHS in laying hens induced by feeding a high-energy, low-protein diet was established. Gas chromatography time-of-flight mass spectrometry (GC-TOF-MS) was used to analyze the metabolites in serum at days 40 and 80. The result showed that, in total, 40 differential metabolites closely related to the occurrence and development of FLHS were screened and identified, which were mainly associated with lipid metabolism, amino acid metabolism, and energy metabolism pathway disorders. Further investigation of differential metabolites showed 10 potential biomarkers such as 3-hydroxybutyric acid, oleic acid, palmitoleic acid, and glutamate were possessed of high diagnostic values by analyzing receiver operating characteristic (ROC) curves. In conclusion, this study showed that the metabolomic method based on GC-TOF-MS can be used in the clinical diagnosis of FLHS in laying hens and provide potential biomarkers for early risk evaluation of FLHS and further insights into FLHS development.

Metabolomic profiling in evaluation of cultivated oat species with different ploidy level

The article presents biochemical characteristics identified during the analysis of metabolomic profiles. The object of this study was the landraces of cultivated oat species Avena strigosa Schreb., A. abyssinica Hochst. and A. sativa L. with different ploidy levels from the global collection of the Department of Genetic Resources of Oats, Rye, and Barley of VIR. Metabolic profiling was performed using an Agilent 6850 gas chromatograph (Agilent Technologies, USA). The main task of this evaluation was determination of differences between cultivated oat species of diploid, tetraploid and hexaploid ploidy levels according to their metabolomic spectra. These spectra reflect the metabolic state of genotypes of various ecological and geographical origin. The investigation touched on the most important groups of metabolites important for the resistance formation nutritional, medicinal and dietary benefits. Particular, attention was paid to biologically active compounds that determine the functional value of daily human foods − phenolic compounds, free amino acids and sugar acids. The most informative indicators, which separate the oat with different ploidy levels were: isofucosterol, xylitol, MAG-1 18: 0, linolenic, undecylic, threonic, glutamic and methylmalonic acids.

A Urine Metabonomics Study of Rat Bladder Cancer by Combining Gas Chromatography-Mass Spectrometry with Random Forest Algorithm

A urine metabolomics study based on gas chromatography-mass spectrometry (GC-MS) and multivariate statistical analysis was applied to distinguish rat bladder cancer. Urine samples with different stages were collected from animal models, i.e., the early stage, medium stage, and advanced stage of the bladder cancer model group and healthy group. After resolving urea with urease, the urine samples were extracted with methanol and, then, derived with N, O-Bis(trimethylsilyl) trifluoroacetamide and trimethylchlorosilane (BSTFA + TMCS, 99 : 1, v/v), before analyzed by GC-MS. Three classification models, i.e., healthy control vs. early- and middle-stage groups, healthy control vs. advanced-stage group, and early- and middle-stage groups vs. advanced-stage group, were established to analyze these experimental data by using Random Forests (RF) algorithm, respectively. The classification results showed that combining random forest algorithm with metabolites characters, the differences caused by the progress of disease could be effectively exhibited. Our results showed that glyceric acid, 2, 3-dihydroxybutanoic acid, N-(oxohexyl)-glycine, and D-turanose had higher contributions in classification of different groups. The pathway analysis results showed that these metabolites had relationships with starch and sucrose, glycine, serine, threonine, and galactose metabolism. Our study results suggested that urine metabolomics was an effective approach for disease diagnosis.

Effect of cassava flour on the lipidic and redox profile of Wistar rats with dyslipidemia

One of the major risk factors for cardiovascular disease is high total cholesterol. It is known that some foods can reduce plasma cholesterol, such as oats. Cassava flour has a similar amount of fiber when compared to oats. The objective of this study was to evaluate the hypocholesterolemic potential of cassava flour. Thirty Wistar rats (eight weeks old) were divided into three groups: control, high-cholesterol diet, high-cholesterol diet + cassava flour, and were treated for 8 weeks. The weight and food consumption of the animals were evaluated weekly. After euthanasia, analyzes of biochemical and oxidative stress profiles were performed, besides the histological analysis of the liver. Cassava flour protected animals from lipoperoxidation, according to thiobarbituric acid-reactive substances results and improved superoxide dismutase activity and thiol content; however, failed to improve the lipid profile and catalase. Cassava flour was possibly able to slow the progression of NASH according to liver histology. PRACTICAL APPLICATIONS: Lifestyle and nutritional habits have been considered important factors associated with the development of dyslipidemia and other chronic diseases. Medicines for chronic diseases are often expensive and have present side effects, and therefore, it is preferable to prevent them through food. Cassava flour is a food widely consumed by Brazilians, which is inexpensive and contains no gluten. Understanding more about one of the most used foods in Brazil is important for health professionals to be able to prescribe it for the correct purposes.

Glucose challenge metabolomics implicates the change of organic acid profiles in hyperlipidemic subjects

Hyperlipidemia (HLP) is a major risk factor of diabetes and cardiovascular disease. Here, we applied gas chromatography-mass spectrometry to study differences in postprandial organic acid profiles in healthy and HLP subjects. In fasting status, six intermediates of the tricarboxylic acid cycle showed significant differences in HLP and healthy controls (P < 0.05). The percentage changes of 17 metabolites including three intermediates of the tricarboxylic acid cycle were significantly different during the oral glucose tolerance test. Postprandial changes in ethylmalonic acid and pimelic acid were negatively associated with HOMA-IR (homeostasis model assessment of insulin resistance; all P < 0.05) in the HLP group. Postprandial metabolism of organic acid profiles revealed energy metabolism perturbations in HLP. Our findings provide new insights into the complex physiological regulation of HLP postprandial metabolism.

Metabolomic characterization of hypertension and dyslipidemia

BACKGROUND

Hypertension and dyslipidemia are two main risk factors for cardiovascular diseases (CVD). Moreover, their coexistence predisposes individuals to a considerably increased risk of CVD. However, the regulatory mechanisms involved in hypertension and dyslipidemia as well as their interactions are incompletely understood.

OBJECTIVES

The aims of our study were to identify metabolic biomarkers and pathways for hypertension and dyslipidemia, and compare the metabolic patterns between hypertension and dyslipidemia.

METHODS

In this study, we performed metabolomic investigations into hypertension and dyslipidemia based on a "healthy" UK population. Metabolomic data from the Husermet project were acquired by gas chromatography-mass spectrometry and ultra-performance liquid chromatography-mass spectrometry. Both univariate and multivariate statistical methods were used to facilitate biomarker selection and pathway analysis.

RESULTS

Serum metabolic signatures between individuals with and without hypertension or dyslipidemia exhibited considerable differences. Using rigorous selection criteria, 26 and 46 metabolites were identified as potential biomarkers of hypertension and dyslipidemia respectively. These metabolites, mainly involved in fatty acid metabolism, glycerophospholipid metabolism, alanine, aspartate and glutamate metabolism, are implicated in insulin resistance, vascular remodeling, macrophage activation and oxidised LDL formation. Remarkably, hypertension and dyslipidemia exhibit both common and distinct metabolic patterns, revealing their independent and synergetic biological implications.

CONCLUSION

This study identified valuable biomarkers and pathways for hypertension and dyslipidemia, and revealed common and different metabolic patterns between hypertension and dyslipidemia. The information provided in this study could shed new light on the pathologic mechanisms and offer potential intervention targets for hypertension and dyslipidemia as well as their related diseases.

Feces and liver tissue metabonomics studies on the regulatory effect of aspirin eugenol eater in hyperlipidemic rats

Background

Based on the pro-drug principle, aspirin and eugenol were esterified to synthesize aspirin eugenol ester (AEE). The anti-hyperlipidemia effect of aspirin eugenol ester has been confirmed in hyperlipidemic rat induced by high fat diet (HFD). However, its effect on liver and feces metabonomic profiles remains unknown.

Methods

Suspension of AEE was prepared in 5% carboxymethyl cellulose sodium (CMC-Na). Thirty rats were divided into control, model and AEE groups. The control and model rats were fed with normal diet or HFD for 13 weeks, respectively. Rats in AEE-treated group were fed with HFD for 8 weeks to induce hyperlipidemia, and then given AEE once daily by oral gavage for 5 weeks at the dosage of 54 mg/kg body weight. After drug intervention, lipid profile analysis and oil red O staining were carried out to confirm the lipid accumulation in liver tissue. UPLC-Q-TOF/MS-based liver and feces metabonomics coupled with pathway analysis were conducted to evaluate the changes of metabolic profile and endogenous metabolites.

Results

In liver tissue, oral administration of AEE significantly reduced lipid droplets and the levels of triglyceride (TG) and low-density lipoprotein (LDL). Using principal component analysis (PCA) and partial least squares-discriminate analysis (PLS-DA), distinct changes in metabolite patterns in feces and liver were observed. Liver and feces samples in control, model and AEE groups were scattered in PLS-DA score plots. 28 metabolites in liver and 22 in feces were identified as potential biomarkers related to hyperlipidemia. As possible drug targets, the perturbations of those biomarkers can be regulated by administration of AEE.

Conclusion

Anti-hyperlipidemia effect of AEE was confirmed by lipid analysis, oil red O staining and metabolomics analysis. The mechanism of AEE might be associated with the changes in the metabolism of glycerophospholipid, amino acid, fatty acid, sphingolipid, purine, bile acid and glutathione.

Electronic supplementary material

The online version of this article (10.1186/s12944-017-0633-0) contains supplementary material, which is available to authorized users.

UPLC-Q-TOF/MS-based urine and plasma metabonomics study on the ameliorative effects of aspirin eugenol ester in hyperlipidemia rats

The main objective of this study was to investigate the ameliorative effects of aspirin eugenol ester (AEE) in hyperlipidemic rat. After five-week oral administration of AEE in high fat diet (HFD)-induced hyperlipidemic rats, the impact of AEE on plasma and urine metabonomics was investigated to explore the underlying mechanism by UPLC-Q-TOF/MS analysis. Blood lipid levels and histopathological changes of liver, stomach and duodenum were also evaluated after AEE treatment. Without obvious gastrointestinal (GI) side effects, AEE significantly relieved fatty degeneration of liver and reduced triglyceride (TG), low density lipoprotein (LDL) and total cholesterol (TCH) (P<0.01). Clear separations of metabolic profiles were observed among control, model and AEE groups by using principal component analysis (PCA) and orthogonal partial least-squares-discriminate analysis (OPLS-DA). 16 endogenous metabolites in plasma and 18 endogenous metabolites in urine involved in glycerophospholipid metabolism, fatty acid metabolism, fatty acid beta-oxidation, amino acid metabolism, TCA cycle, sphingolipid metabolism, gut microflora and pyrimidine metabolism were considered as potential biomarkers of hyperlipidemia and be regulated by AEE administration. It might be concluded that AEE was a promising drug candidate for hyperlipidemia treatment. These findings could contribute to the understanding of action mechanisms of AEE and provide evidence for further studies.

Serum metabolomics reveals the mechanistic role of functional foods and exercise for obesity management in rats

Obesity is one of the independent risk factors for several health problems, leading to metabolic perturbations and for which analytical approaches i.e., "metabolomics" is needed to monitor the underlying metabolic changes. In this study, obesity associated changes were assessed via serum metabolites analysis of obese rats fed on high fat diet. Obese rats were subsequently treated with different functional foods used for obesity management including pomegranate, grapefruit, and red cabbage in parallel to swimming exercise. Serum samples were analyzed using gas chromatography-mass spectrometry (GC-MS) followed by multivariate data analysis to classify samples and determine if such treatments can help revert obesity related metabolic changes back to normal status. Results led to the identification of several novel metabolites biomarkers for obesity related to lipids, amino acids and central tricarboxylic acid (TCA) pathways. Distinct variations in metabolite levels were recorded in obese rats compared to normal ones including l-aspartic, l-alanine, l-glutamine, l-glycine, phenylethanolamine, α-aminobutyric acid and β-hydroxybutyric acid. Metabolomics approach developed herein provides novel insight onto the metabolic disturbances associated with obesity, which will assist in future drug design that can help mitigate against such changes.

Identification of weak and gender specific effects in a short 3 weeks intervention study using barley and oat mixed linkage β-glucan dietary supplements: a human fecal metabolome study by GC-MS

INTRODUCTION

Mixed-linkage (1→3),(1→4)-β-d-glucans (BG) reduce cholesterol level and insulin response in humans. Despite this, their role in human metabolism and a mode of action remains largely unknown.

OBJECTIVES

To investigate the effects of three structurally different BG on human fecal metabolome in a full cross-over intervention using GC-MS metabolomics.

METHODS

Over three weeks of intervention, young healthy adults received food supplemented with BG from oat, two different BG from barley or a non-fiber control in a full cross-over design. Untargeted metabolomics and short chain fatty acid analysis was performed on day three fecal samples. ANOVA-simultaneous component analysis was applied to partition the data variation according to the study design, and PLS-DA was used to select most discriminative metabolite markers.

RESULTS

Univariate and multivariate data analysis revealed a dominating effect of inter-individual variances followed by a gender effect. Weak effects of BG intake were identified including an increased level of gamma-amino-butyrate and palmitoleic acid in males and a decreased level of enterolactone in females. Barley and oat derived BG were found to influence the human fecal metabolome differently. Barley BG increased the relative level of formate in males and isobutyrate, isovalerate, 2-methylbutyrate in females. In total 15, 3 and 11 human fecal metabolites were significantly different between control vs. BG, control vs. oat BG, and barley BG vs. oat BG, respectively.

CONCLUSIONS

The study show that human fecal metabolome largely reflects individual (∼28% variation) and gender (∼15% variation) differences, whereas the treatment effect of the BG (∼8% variation) only manifests in a few key metabolites (primarily by the metabolites: d-2-aminobutyric acid, palmitoleic acid, linoleic acid and 11-eicosenoic acid).