An NMR-based metabonomic investigation of the subacute effects of melamine in rats

Causal association between blood metabolites and risk of hypertension: a Mendelian randomization study

Background

Previous studies have indicated a strong link between blood metabolites and hypertension, however the causality of metabolites and hypertension is unknown.

Methods

Two-sample Mendelian randomization (MR) analysis was performed to assess the causal relationship between 486 blood metabolites and essential hypertension (EHT). Blood metabolite GWAS data was utilized as the exposure, with EHT GWAS data as the outcome. To further verify the results, another different source of EHT GWAS data was repeatedly analyzed. The major MR analytic approach used to determine causality was inverse variance weighted (IVW), with MR-Egger, Weighted Median, and MR-PRESSO models serving as supplements. We used the Cochran Q test to examine heterogeneity. Horizontal pleiotropy was examined using MR-Egger intercept and MR-PRESSO global test. The MR Steiger test confirmed the causal relationship between blood metabolites and EHT.

Results

In this study, nine blood metabolites associated with EHT were preliminarily identified by MR analysis, including four known metabolites (N-acetylornithine, X-12510-2-aminooctanoic acid, creatine, hexadecanedioate) and five unknown metabolites. Then another source of EHT GWAS data was repeatedly analyzed for further verification, and two overlapped metabolites (N-acetylornithine, X-12510-2-aminooctanoic acid) were found. There was a negative correlation between N-acetylornithine and EHT (OR = 0.987, 95% CI = 0.980-0.993, P = 1.01 × 10-4), Cochran's Q test suggested there was no heterogeneity (Q = 31.7586, P = 0.1331), MR-Egger intercept and MR-PRESSO global test suggested there was no horizontal pleiotropy (P > 0.05), Leave-one-out analysis indicated that no single single-nucleotide polymorphism (SNP) had a significant effect on the results, and MR Steiger test confirmed that the direction of causality was correct (P < 0.001). There was a negative correlation between X-12510-2-aminooctanoic acid and EHT (OR = 0.982, 95% CI = 0.972-0.993, P = 0.0017), and there was no evidence of heterogeneity or pleiotropy in multiple sensitivity analyses.

Conclusion

The study discovered some blood metabolites causally linked to EHT, which might lead to new understandings of the pathophysiology of hypertension.

Metabolomic analysis of the serum and urine of rats exposed to diazinon, dimethoate, and cypermethrin alone or in combination

BACKGROUND

Multiple pesticides are often used in combination for plant protection and public health. Therefore, it is important to analyze the physiological changes induced by multiple pesticides exposure. The objective of this study was to investigate the combined toxicity of the widely-used organophosphorus and pyrethroid pesticides diazinon, dimethoate, and cypermethrin.

METHODS

Male Wistar rats were administrated by gavage once daily with the three pesticides individual or in combination for consecutive 28 days. The metabolic components of serum and urine samples were detected by using 1H nuclear magnetic resonance (NMR)-based metabolomics method. Histopathological examination of liver and kidneys and serum biochemical determination were also carried out.

RESULTS

The results showed that after the 28-day subacute exposure, serum glutamic transaminase and albumin were significantly increased and blood urea nitrogen was significantly decreased in the rats exposed to the mixture of the pesticides compared with the control rats, suggesting that the co-exposure impaired liver and kidney function. Metabolomics analysis indicated that the indicators 14 metabolites were statistically significant altered in the rats after the exposure of the pesticides. The increase in 3-hydroxybutyric acid in urine or decrease of lactate and N-acetyl-L-cysteine in serum could be a potentially sensitive biomarker of the subchronic combined effects of the three insecticides. The reduction level of 2-oxoglutarate and creatinine in urine may be indicative of dysfunction of liver and kidneys.

CONCLUSION

In summary, the exposure of rats to pesticides diazinon, dimethoate, and cypermethrin could cause disorder of lipid and amino acid metabolism, induction of oxidative stress, and dysfunction of liver and kidneys, which contributes to the understanding of combined toxic effects of the pesticides revealed by using the metabolomics analysis of the urine and serum profiles.

Lipidized PrRP Analog Exhibits Strong Anti-Obesity and Antidiabetic Properties in Old WKY Rats with Obesity and Glucose Intolerance

Prolactin-releasing peptide (PrRP) is an anorexigenic neuropeptide that has potential for the treatment of obesity and its complications. Recently, we designed a palmitoylated PrRP31 analog (palm¹¹-PrRP31) that is more stable than the natural peptide and able to act centrally after peripheral administration. This analog acted as an anti-obesity and glucose-lowering agent, attenuating lipogenesis in rats and mice with high-fat (HF) diet-induced obesity. In Wistar Kyoto (WKY) rats fed a HF diet for 52 weeks, we explored glucose intolerance, but also prediabetes, liver steatosis and insulin resistance-related changes, as well as neuroinflammation in the brain. A potential beneficial effect of 6 weeks of treatment with palm¹¹-PrRP31 and liraglutide as comparator was investigated. Liver lipid profiles, as well as urinary and plasma metabolomic profiles, were measured by lipidomics and metabolomics, respectively. Old obese WKY rats showed robust glucose intolerance that was attenuated by palm¹¹-PrRP31, but not by liraglutide treatment. On the contrary, liraglutide had a beneficial effect on insulin resistance parameters. Despite obesity and prediabetes, WKY rats did not develop steatosis owing to HF diet feeding, even though liver lipogenesis was enhanced. Plasma triglycerides and cholesterol were not increased by HFD feeding, which points to unincreased lipid transport from the liver. The liver lipid profile was significantly altered by a HF diet that remained unaffected by palm¹¹-PrRP31 or liraglutide treatment. The HF-diet-fed WKY rats revealed astrogliosis in the brain cortex and hippocampus, which was attenuated by treatment. In conclusion, this study suggested multiple beneficial anti-obesity-related effects of palm¹¹-PrRP31 and liraglutide in both the periphery and brain.

Hepatotoxic effects of melamine exposure from the weaning period in rats: a flow cytometric, electron microscopic, and histopathologic study

This study aims to investigate the effects of melamine exposure from the weaning period (21st postnatal days in rats) on liver tissue. Female Wistar albino rats (n = 18) were divided into three groups. About 0.1-ml saline was applied to the control group by gavage for 21 days from the postnatal 21st day. The second group was taken 50-mg/kg melamine (in 0.1-ml saline) and the third group was taken 75-mg/kg melamine (in 0.1-ml saline) p.o. On the postnatal 45th day, all rats were sacrificed under anesthesia. Then, liver tissues were cut into three parts and two of them placed in neutral formalin for histopathological and flow cytometric analysis, and one of them placed in 2.5% glutaraldehyde. Histopathological analysis was performed with hematoxylin & eosin, Masson trichrome, periodic acid Schiff stained sections, and also with transmission electron microscopy. Apoptosis (Annexin V positivity) was analyzed by flow cytometry. According to histopathological analysis, hepatocyte damage, sinusoidal dilatation, and inflammatory cell infiltration significantly increased in both melamine groups compared with the control group. Apoptosis significantly increased in the 50 and 75-mg melamine groups compared with the control group. In the results of transmission electron microscopy analysis, there was abnormal chromatin distribution in the hepatocyte nuclei, loss in the cristae of the mitochondria, and organelle loss in large areas in the cytoplasm in both melamine exposure groups. As result, melamine exposure from the weaning period causes liver damage with increasing doses.

Urinary Metabonomic Profiling Discriminates Between Children with Autism and Their Healthy Siblings

Background

Autism spectrum disorder (ASD) is a complicated neuropsychiatric disease that displays significant heterogeneity. The diagnosis of ASD is currently primarily dependent upon descriptions of clinical symptoms, and it remains urgent to find biological markers for the detection and diagnosis of autism. The current study applied the urinary metabolic profiling approach to characterize metabolic phenotypes in ASD.

Material/Methods

Urine was obtained from children with ASD and their matched healthy siblings. Samples were analyzed using ¹H NMR-based methods designed to measure a broad range of metabolites. Partial least-square-discriminant analysis (PLS-DA) was used to develop models to identify metabonomic variations that can be used to distinguish between individuals with ASD and their unaffected siblings.

Results

A significant difference was observed between the metabolomic profiles of children with ASD and that of their healthy siblings. An increase in the levels of tryptophan, hippurate, glycine, and creatine, and a decrease in trigonelline, melatonin, pantothenate, serotonin, and taurine were observed compared to the control group. We conclude that several metabolic pathways are affected by autism, which suggests that a gut-brain link may be important in the pathophysiology of ASD.

Conclusions

¹H NMR-based metabonomic analysis of the urine can determine perturbations of specific metabolic pathways related to ASD and help identify a characteristic metabolic fingerprint to better understand the disease and its causes.

NMR as a "Gold Standard" Method in Drug Design and Discovery

Studying disease models at the molecular level is vital for drug development in order to improve treatment and prevent a wide range of human pathologies. Microbial infections are still a major challenge because pathogens rapidly and continually evolve developing drug resistance. Cancer cells also change genetically, and current therapeutic techniques may be (or may become) ineffective in many cases. The pathology of many neurological diseases remains an enigma, and the exact etiology and underlying mechanisms are still largely unknown. Viral infections spread and develop much more quickly than does the corresponding research needed to prevent and combat these infections; the present and most relevant outbreak of SARS-CoV-2, which originated in Wuhan, China, illustrates the critical and immediate need to improve drug design and development techniques. Modern day drug discovery is a time-consuming, expensive process. Each new drug takes in excess of 10 years to develop and costs on average more than a billion US dollars. This demonstrates the need of a complete redesign or novel strategies. Nuclear Magnetic Resonance (NMR) has played a critical role in drug discovery ever since its introduction several decades ago. In just three decades, NMR has become a "gold standard" platform technology in medical and pharmacology studies. In this review, we present the major applications of NMR spectroscopy in medical drug discovery and development. The basic concepts, theories, and applications of the most commonly used NMR techniques are presented. We also summarize the advantages and limitations of the primary NMR methods in drug development.

The effects of hexaconazole and epoxiconazole enantiomers on metabolic profile following exposure to zebrafish (Danio rerio) as well as the histopathological changes

Hexaconazole and epoxiconazole are the worldwidely used fungicides. However, limited information is known about the toxicological effects of their enantiomers on aquatic organisms. In this study, zebrafish were separately exposed to 100 and 1000 μgL^-1 hexaconazole and epoxiconazole enantiomers for 21 d ¹H NMR-based metabolomics analysis showed that the exposure of low and high dose of hexaconazole enantiomers altered energy metabolism, lipid metabolism and amino acid metabolism of zebrafish, with the different metabolic profiles resulted from the same dose of (+)-hexaconazole and (-)-hexaconazole. Similar to hexaconazole enantiomers, the metabolic profiles, including the changes related to energy metabolism, lipid metabolism and amino acid metabolism, were demonstrated in low and high dose epoxiconazole enantiomers treatment groups. There are differences in the metabolic profiles of zebrafish between exposed to (+)-epoxiconazole and (-)-epoxiconazole of the same dose. The results of histological examination revealed that the exposure of both enantiomers for hexaconazole and epoxiconazole resulted in the similar histopathological changes. The exposure of hexaconazole and epoxiconazole enantiomers at low and high dose resulted the vacuolization and swell in the liver of the female and male zebrafish. Compared to female zebrafish, more liver damage was found in male zebrafish in the hexaconazole enantiomers exposure groups. The reduction of spermatids was observed in hexaconazole and epoxiconazole enantiomers treatment groups of both doses. Hexaconazole enantiomers exposure of low and high dose resulted the increase in the number of mature eggs, while such effect was not observed in epoxiconazole enantiomers exposure groups. Hexaconazole and epoxiconazole enantiomers exposure resulted in no changes in brains of female and male zebrafish. As a result, both triazole-based chiral bactericides, hexaconazole and epoxiconazole, have similar toxicological effects but their mechanisms of action are not exactly the same. The above results will play an important part in making the differences in toxic effects of hexaconazole and epoxiconazole enantiomers clear. What's more, it is an indispensable part for an integrated environmental risk assessment.

Toxicity and metabolomics study of isocarbophos in adult zebrafish (Danio rerio)

Although isocarbophos is a widely used insecticide, its toxicity to aquatic organisms has not been well characterized. In this study, zebrafish were exposed to isocarbophos at concentrations of 50 µg L^-1 and 200 µg L^-1 to assess its bioaccumulation, metabolic disruption, and oxidative stress. Metabolomics analysis based on ¹H NMR spectroscopy showed that 50 µg L^-1 and 200 µg L^-1 isocarbophos exposure induced increases in leucine, isoleucine, valine, and alanine compared to levels in the control. Lactate, creatine, and taurine were reduced in the 50 µg L^-1 isocarbophos exposure group, and only lactate decreased in response to 200 µg L^-1 isocarbophos. After zebrafish were exposed to 50 and 200 µg L^-1 isocarbophos for 28 days, the activities of antioxidant enzymes (SOD, CAT, and GPx) and GSH contents decreased significantly in the liver. This result indicates that there was significant oxidative stress in the liver. Furthermore, changes in metabolite profiles significantly covaried with changes in several oxidative stress endpoints based on partial least squares regression. These results will contribute to the environmental risk assessment of isocarbophos and clarify the mechanism underlying its toxicity in zebrafish.

Metabolic Profiling Analysis of the Alleviation Effect of the Fractions of Niuhuang Jiedu Tablet on Realgar Induced Toxicity in Rats

Niuhuang Jiedu Tablet (NJT) is a classical formula in treating acute tonsillitis, pharyngitis, and so on. In the formula, significant level of Realgar as a potentially toxic element is contained. Our previous experiments revealed that it was less toxic for combined Realgar in NJT. However, the active fraction of this prescription with toxicity alleviation effect on Realgar was still obscure. NJT was divided into five different polar fractions (NJT-PET, NJT-25, NJT-50, NJT-75, and NJT-95), and we explored the toxicity alleviation effect on Realgar. Based on 1H NMR spectra of urine and serum from rats, PCA and PLS-DA were performed to identify different metabolic profiles. Liver and kidney histopathology examinations and serum clinical chemistry analysis were also performed. With pattern recognition analysis of metabolites in urine and serum, Realgar group showed a clear separation from control group, while the metabolic profiles of NJT-PET, NJT-25, NJT-50, and NJT-95 groups were similar to Realgar group, and the metabolic profiles of NJT and NJT-75 groups were very close to control group. Statistics results were confirmed by the histopathological examination and biochemical assay. The present work indicated that 75% EtOH fraction of NJT was the most valid fraction with the toxicity alleviation effect on Realgar.

Enantioselective bioaccumulation following exposure of adult zebrafish (Danio rerio) to epoxiconazole and its effects on metabolomic profile as well as genes expression

Although epoxiconazole is the worldwidely used fungicide, limited information is known about its toxic effects and bioaccumulation behavior in freshwater ecosystems. In this study, zebrafish were exposed to epoxiconazole at concentrations of 100 and 1000 μg L^-1 for 21 d. ¹H NMR-based metabolomics analysis showed that low- and high-dose epoxiconazole exposure resulted in two similar but not identical patterns for the change of endogenous metabolites related to energy, lipid and amino acid metabolism. The expression of genes associated with mitochondrial respiratory chain, ATP synthesis and fatty acid β-oxidation were further measured to explore the reason for the disturbed energy metabolism, finding epoxiconazole had an inhibition effect on the genes expression of the above ways. Significant enantioselectivity was observed with (+)-epoxiconazole enrichment in the bioaccumulation process. These results will be of great importance in understanding the toxic effects induced by epoxiconazole and provide important basis for its comprehensive environmental assessment.

Impact of novel palmitoylated prolactin-releasing peptide analogs on metabolic changes in mice with diet-induced obesity

Analogs of anorexigenic neuropeptides, such as prolactin-releasing peptide (PrRP), have a potential as new anti-obesity drugs. In our previous study, palmitic acid attached to the N-terminus of PrRP enabled its central anorexigenic effects after peripheral administration. In this study, two linkers, γ-glutamic acid at Lys¹¹ and a short, modified polyethylene glycol at the N-terminal Ser and/or Lys¹¹, were applied for the palmitoylation of PrRP31 to improve its bioavailability. These analogs had a high affinity and activation ability to the PrRP receptor GPR10 and the neuropeptide FF2 receptor, as well as short-term anorexigenic effect similar to PrRP palmitoylated at the N-terminus. Two-week treatment with analogs that were palmitoylated through linkers to Lys¹¹ (analogs 1 and 2), but not with analog modified both at the N-terminus and Lys¹¹ (analog 3) decreased body and liver weights, insulin, leptin, triglyceride, cholesterol and free fatty acid plasma levels in a mouse model of diet-induced obesity. Moreover, the expression of uncoupling protein-1 was increased in brown fat suggesting an increase in energy expenditure. In addition, treatment with analogs 1 and 2 but not analog 3 significantly decreased urinary concentrations of 1-methylnicotinamide and its oxidation products N-methyl-2-pyridone-5-carboxamide and N-methyl-4-pyridone-3-carboxamide, as shown by NMR-based metabolomics. This observation confirmed the previously reported increase in nicotinamide derivatives in obesity and type 2 diabetes mellitus and the effectiveness of analogs 1 and 2 in the treatment of these disorders.

Metabolomics study of the therapeutic mechanism of Schisandra Chinensis lignans in diet-induced hyperlipidemia mice

Background

Schisandra, a globally distributed plant, has been widely applied for the treatment of diseases such as hyperlipidemia, fatty liver and obesity in China. In the present work, a rapid resolution liquid chromatography coupled with quadruple-time-of-flight mass spectrometry (RRLC-Q-TOF-MS)-based metabolomics was conducted to investigate the intervention effect of Schisandra chinensis lignans (SCL) on hyperlipidemia mice induced by high-fat diet (HFD).

Methods

Hyperlipidemia mice were orally administered with SCL (100 mg/kg) once a day for 4 weeks. Serum biochemistry assay of triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-c) and high-density lipoprotein cholesterol (HDL-c) was conducted to confirm the treatment of SCL on lipid regulation. Metabolomics analysis on serum samples was carried out, and principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) were carried out for the pattern recognition and characteristic metabolites identification. The relative levels of critical regulatory factors of liver lipid metabolism, sterol regulatory element-binding proteins (SREBPs) and its related gene expressions were measured by quantitative real-time polymerase chain reaction (RT-PCR) for investigating the underlying mechanism.

Results

Oral administration of SCL significantly decreased the serum levels of TC, TG and LDL-c and increased the serum level of HDL-c in the hyperlipidemia mice, and no effect of SCL on blood lipid levels was observed in control mice. Serum samples were scattered in the PCA scores plots in response to the control, HFD and SCL group. Totally, thirteen biomarkers were identified and nine of them were recovered to the normal levels after SCL treatment. Based on the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways analysis, the anti-hyperlipidemia mechanisms of SCL may be involved in the following metabolic pathways: tricarboxylic acid (TCA) cycle, synthesis of ketone body and cholesterol, choline metabolism and fatty acid metabolism. Meanwhile, SCL significantly inhibited the mRNA expression level of hepatic lipogenesis genes such as SREBP-1c, fatty acid synthase (FAS) and acetyl-CoA carboxylase (ACC), and decreased the mRNA expression of liver X receptor α (LXRα). Moreover, SCL also significantly decreased the expression level of SREBP-2 and 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR) in the liver of hyperlipidemia mice.

Conclusion

Anti-hyperlipidemia effect of SCL was confirmed by both serum biochemistry and metabolomics analysis. The mechanism may be related to the down-regulation of LXRα/SREBP-1c/FAS/ACC and SREBP2/HMGCR signaling pathways.

1H NMR-based metabolomics analysis of adult zebrafish (Danio rerio) after exposure to diniconazole as well as its bioaccumulation behavior

As a systemic triazole fungicide, limited information is known about diniconazole. In this study, toxicological effects and bioaccumulation behavior of diniconazole in zebrafish were both evaluated to perform an overall assessment of its environmental risk towards aquatic organisms. The ¹H NMR-based metabolomics analysis revealed that 70 μg L^-1 diniconazole exposure increased valine, leucine, isoleucine, alanine, lactate and choline, accompanied by decreased glucose, creatine and taurine, in comparison to the control. In the exposure group of 300 μg L^-1 diniconazole, only down-regulated glucose and creatine were observed. The above results indicated that diniconazole disturbed energy metabolism, amino acid metabolism and lipid metabolism. Histological examination showed that the swell and vacuolization in the liver, as well as the reduction of spermatids in the diniconazole exposure groups. No enantioselectivity was observed in the bioaccumulation process of both 70 and 300 μg L^-1 diniconazole exposure groups. The above results play a vital role for a comprehensive environmental assessment of diniconazole.

A comparative study of the main constituents and antidepressant effects of raw and vinegar-baked Bupleuri Radix in rats subjected to chronic unpredictable mild stress

Bupleuri Radix (BR) is a traditional Chinese medicine (TCM) widely used in Asian nations, which originates fromBupleurum chinenseDC orBupleurum scorzonerifoliumWilld.

Metabolomic Study on Idiosyncratic Liver Injury Induced by Different Extracts of Polygonum multiflorum in Rats Integrated with Pattern Recognition and Enriched Pathways Analysis

Currently, numerous liver injury cases related to a famous Chinese herb- Polygonum Multiflorum (Heshouwu in Chinese) have attracted great attention in many countries. Our previous work showed that Heshouwu-induced hepatotoxicity belonged to idiosyncratic drug-induced liver injury (IDILI). Unfortunately, the components and mechanisms attributed to IDILI of Heshouwu are difficult to determine and thus remain unknown. Attempts to explore puzzles, we prepared the chloroform (CH)-, ethyl acetate (EA)-, and residue (RE) extracts of Heshouwu to investigate IDILI constituents and underlying mechanisms, using biochemistry, histopathology, and metabolomics examinations. The results showed that co-treatment with non-toxic dose of lipopolysaccharide (LPS) and EA extract could result in evident liver injury, indicated by the significant elevation of plasma alanine aminotransferase and aspartate aminotransferase activities, as well as obvious liver histologic damage; whereas other two separated fractions, CH and RE extracts, failed to induce observable liver injury. Furthermore, 21 potential metabolomic biomarkers that differentially expressed in LPS/EA group compared with other groups without liver injury were identified by untargeted metabolomics, mainly involved two pathways: tricarboxylic acid cycle and sphingolipid metabolism. This work illustrated EA extract had close association with the idiosyncratic hepatotoxicity of Heshouwu and provided a metabolomic insight into IDILI of different extracts from Heshouwu.

Single-walled carbon nanotubes disturbed the immune and metabolic regulation function 13-weeks after a single intratracheal instillation

Due to their unique physicochemical properties, the potential health effects of single-walled carbon nanotubes (SWCNTs) have attracted continuous attention together with their extensive application. In this study, we aimed to identify local and systemic health effects following pulmonary persistence of SWCNTs. As expected, SWCNTs remained in the lung for 13 weeks after a single intratracheal instillation (50, 100, and 200μg/kg). In the lung, the total number of cells and the percentages of lymphocytes and neutrophils significantly increased at 200μg/kg compared to the control, and the Th1-polarized immune response was induced accompanying enhanced expression of tissue damage-related genes and increased release of chemokines. Additionally, SWCNTs enhanced the expression of antigen presentation-related proteins on the surface of antigen-presenting cells, however, maturation of dendritic cells was inhibited by their persistence. As compared to the control, a significant increase in the percentage of neutrophils and a remarkable decrease of BUN and potassium level were observed in the blood of mice treated with the highest dose. This was accompanied by the down-regulation of the expression of antigen presentation-related proteins on splenocytes. Moreover, protein and glucose metabolism were disturbed with an up-regulation of fatty acid β-oxidation. Taken together, we conclude that SWCNTs may induce adverse health effects by disturbing immune and metabolic regulation functions in the body. Therefore, careful application of SWCNTs is necessary for the enforcement of safety in nano-industries.

NMR- and LC-MS/MS-based urine metabolomic investigation of the subacute effects of hexabromocyclododecane in mice

In the present study, both untargeted and targeted metabolomics approaches were used to evaluate the subacute effects of hexabromocyclododecane (HBCD) on mice urine metabolome. Untargeted metabolomics based on (1)H NMR showed that HBCD exposure disturbed mice metabolism in both dosed groups, especially in high dosed group. The low-dose HBCD led to a decrease in alanine, malonic acid, and trimethylamine (TMA). High-dose HBCD-treated mice developed high levels of citric acid and 2-ketoglutarate, together with decreased alanine, acetate, formate, TMA, 3-hydroxybutyrate, and malonic acid. Targeted metabolomics for metabolic profiling of 20 amino acids identified alanine, lysine, and phenylalanine as significantly disturbed metabolites. These results indicated that subchronic exposure to HBCD caused a disturbance of mice metabolism, especially in TCA cycle, lipid metabolism, gut microbial metabolism, and homeostasis of amino acids, and the application of untargeted and targeted metabolomics combined with conventional toxicology approaches to evaluate the subacute effects of pollutants will provide more comprehensive information and aid in predicting health risk of these pollutants.

Huang-Lian-Jie-Du decoction treated sepsis via regulating ERK and SRC/STAT3 pathways and ameliorating metabolic status

LPS disturbed the metabolomic profiles and activated the ERK and SRC/STAT3 signaling pathways of mice, and HLJDD exerted therapeutic effects on sepsis induced by LPS.

(1)H NMR-based metabolic profiling of liver in chronic unpredictable mild stress rats with genipin treatment

Genipin, a hydrolyzed metabolite of geniposide extracted from the fruit of Gardenia jasminoides Ellis, has shown promise in alleviating depressive symptoms, however, the antidepressant mechanism of genipin remains unclear and incomprehensive. In this study, the metabolic profiles of aqueous and lipophilic extracts in liver of the chronic unpredictable mild stress (CUMS)-induced rat with genipin treatment were investigated using proton nuclear magnetic resonance ((1)H NMR) spectroscopy coupled with multivariate data analysis. Significant differences in the metabolic profiles of rats in the CUMS model group (MS) and the control group (NS) were observed with metabolic effects including decreasing in choline, glycerol and glycogen, increasing in lactate, alanine and succinate, and a disordered lipid metabolism, while the moderate dose (50mg/kg) of genipin could significantly regulate the concentrations of glycerol, lactate, alanine, succinate and the lipid to their normal levels. These biomakers were involved in metabolism pathways such as glycolysis/gluconeogensis, tricarboxylic acid (TCA) cycle and lipid metabolism, which may be helpful for understanding of antidepressant mechanism of genipin.

Urine and serum metabolite profiling of rats fed a high-fat diet and the anti-obesity effects of caffeine consumption

In this study, we investigated the clinical changes induced by a high fat diet (HFD) and caffeine consumption in a rat model. The mean body weight of the HFD with caffeine (HFDC)-fed rat was decreased compared to that of the HFD-fed rat without caffeine. The levels of cholesterol, triglycerides (TGs), and free fatty acid, as well as the size of adipose tissue altered by HFD, were improved by caffeine consumption. To investigate the metabolites that affected the change of the clinical factors, the urine and serum of rats fed a normal diet (ND), HFD, and HFDC were analyzed using ultra performance liquid chromatography quadruple time-of-flight mass spectrometry (UPLC-Q-TOF-MS), gas chromatography (GC-TOF-MS), and linear trap quadruple mass spectrometry (LTQ-XL-MS) combined with multivariate analysis. A total of 68 and 52 metabolites were found to be different in urine and serum, respectively. After being fed caffeine, some glucuronide-conjugated compounds, lysoPCs, CEs, DGs, TGs, taurine, and hippuric acid were altered compared to the HFD group. In this study, caffeine might potentially inhibit HFD-induced obesity and we suggest possible biomarker candidates using MS-based metabolite profiling.

Rapid colorimetric detection of melamine by H2O2–Au nanoparticles

A simple, rapid and sensitive detection method by the naked eye for melamine in dairy products is reported.

Toxicity assessment of Arisaematis Rhizoma in rats by a 1H NMR-based metabolomics approach

A ¹H NMR based metabolomics approach combined with serum biochemistry and histopathological examination was used to study the toxicity of Arisaematis Rhizoma by intragastrical administration for the first time.

A metabolic profiling analysis of the acute toxicological effects of the realgar (As₂S₂) combined with other herbs in Niuhuang Jiedu Tablet using ¹H NMR spectroscopy

ETHNOPHARMACOLOGICAL RELEVANCE

Niuhuang Jiedu Tablet (NJT), composed of Realgar (As₂S₂), Bovis Calculus Artificialis, Borneolum Synthcticum, Gypsum Fibrosum, Rhei Radix et Rhizoma (RR), Scutellariae Radix (SR), Platycodonis Radix (PR) and Glycyrrhizae Radix et Rhizoma (GR), is an effective formula of traditional Chinese medicine (TCM) used in treating acute tonsillitis, pharyngitis, periodontitis and mouth ulcer. In the formula, significant level of realgar (As₂S₂) as a potentially toxic element is contained. In our pervious experiments, NJT was significantly less toxic than realgar (As₂S₂), and the material bases of toxicity alleviation effect to realgar (As₂S₂) were RR, SR, PR and GR. However, the toxicity alleviation effect of each above mentioned four herbs to realgar (As₂S₂) and their synergistic detoxification effects to realgar (As₂S₂) were still obscure.

MATERIALS AND METHODS

Male Wistar rats were divided into 11 groups: control, group R (treated with Realgar), group RRSPG (treated with Realgar, RR, SR, PR and GR), group RRSP (treated with Realgar, RR, SR and PR), group RRSG (treated with Realgar, RR, SR and GR), group RRPG (treated with Realgar, RR, PR and GR), group RSPG (treated with Realgar, SR, PR and GR), group RR (treated with Realgar and RR), group RS (treated with Realgar and SR), group RP (treated with Realgar and PR) and group RG (treated with Realgar and GR). Based on (1)H NMR spectra of urine and serum from rats, PCA and PLS-DA were performed to identify different metabolic profiles. Liver and kidney histopathology examinations and serum clinical chemistry analysis were also performed.

RESULTS

The metabolic profiles of groups RR, RS, RP and RG were similar to those of group R, while the metabolic profiles of groups RRSPG, RRSP, RRSG, RRPG and RSPG were almost in line with those of control group. Statistics results were confirmed by the histopathological examination and biochemical assay.

CONCLUSION

The present work suggested that the toxicity alleviation effects of RR, SR, PR and GR to realgar (As₂S₂) were not obvious when combined with realgar (As₂S₂) respectively, but they had synergistic detoxification effects on realgar (As₂S₂) mutually.

A (1)H NMR-Based Metabonomic Investigation of Time-Related Metabolic Trajectories of the Plasma, Urine and Liver Extracts of Hyperlipidemic Hamsters

The hamster has been previously found to be a suitable model to study the changes associated with diet-induced hyperlipidemia in humans. Traditionally, studies of hyperlipidemia utilize serum- or plasma-based biochemical assays and histopathological evaluation. However, unbiased metabonomic technologies have the potential to identify novel biomarkers of disease. Thus, to obtain a better understanding of the progression of hyperlipidemia and discover potential biomarkers, we have used a proton nuclear magnetic resonance spectroscopy (¹H-NMR)-based metabonomics approach to study the metabolic changes occurring in the plasma, urine and liver extracts of hamsters fed a high-fat/high-cholesterol diet. Samples were collected at different time points during the progression of hyperlipidemia, and individual proton NMR spectra were visually and statistically assessed using two multivariate analyses (MVA): principal component analysis (PCA) and orthogonal partial least squares-discriminant analysis (OPLS-DA). Using the commercial software package Chenomx NMR suite, 40 endogenous metabolites in the plasma, 80 in the urine and 60 in the water-soluble fraction of liver extracts were quantified. NMR analysis of all samples showed a time-dependent transition from a physiological to a pathophysiological state during the progression of hyperlipidemia. Analysis of the identified biomarkers of hyperlipidemia suggests that significant perturbations of lipid and amino acid metabolism, as well as inflammation, oxidative stress and changes in gut microbiota metabolites, occurred following cholesterol overloading. The results of this study substantially broaden the metabonomic coverage of hyperlipidemia, enhance our understanding of the mechanism of hyperlipidemia and demonstrate the effectiveness of the NMR-based metabonomics approach to study a complex disease.

1H NMR-based metabonomic analysis of the serum and urine of rats following subchronic exposure to dichlorvos, deltamethrin, or a combination of these two pesticides

Metabonomic analysis, clinical chemical analysis and histopathology were used to investigate the toxic effects of subchronic exposure to dichlorvos, deltamethrin, and a combination of these two pesticides, in rats. Weight loss, hind limb weakness and histopathological changes in kidney tissue were only observed in rats exposed to high doses of deltamethrin, or a combination of deltamethrin and dichlorvos. Urinary metabonomic analysis indicated that exposure to a mixture of dichlorvos and deltamethrin was followed by increases in urinary lactate, dimethylamine, N-glycoprotein (NAC) and glycine similar to those observed in rats treated with either dichlorvos or deltamethrin alone. Serum metabonomic analysis suggests that dichlorvos induced an increase in lactate and alanine and a decrease in dimethylglycine (DMG), NAC and very low- and low-density lipoprotein (VLDL/LDL). High levels of lactate and low levels of NAC and VLDL/LDL were observed in the deltamethrin treatment group. Treating rats with a mixture of dichlorvos and deltamethrin caused an increase in serum lactate, trimethylamine-N-oxide (TMAO), choline and alanine, with the highest levels of these metabolites observed in those that received the highest dose. Exposure to a mixture of dichlorvos and deltamethrin also resulted in a decrease in serum acetone, DMG, NAC, and VLDL/LDL. Changes in serum TMAO, alanine, choline and acetone in this treatment group were higher than in rats treated with either dichlorvos or deltamethrin. These results suggest that exposing rats to subchronic doses of dichlorvos, deltamethrin, or a combination of these pesticides, disrupted the energy metabolism of the liver and reduced kidney function.

Four years follow-up of 101 children with melamine-related urinary stones

The melamine-contaminated milk powder incidence occurred in China in 2008. Many studies have been published regarding the epidemiology, clinical symptoms, diagnosis and treatment of melamine-related urinary stones. The objective of this study is to follow-up the effects of melamine-contaminated milk powder consumption on kidney and body growth in children with melamine-related urinary stones 4 years ago. One hundred and one children with melamine-related urinary stones were followed up by urinalysis, renal function tests and urinary ultrasonography. The data of body weight and height, clinical signs and complications were collected. Eighty normal children without the history of consuming melamine-contaminated milk powder were collected as controls. Eighty-one children with melamine-related urinary stones were successfully followed up. Of 45 cases with melamine-related urinary stones treated conservatively after discharge, 34 disappeared completely, 6 dissolved partially, 1 increased in size and 4 did not change at 4 years follow-up. The percentages of under-height and under-weight infants were significantly higher in melamine-related urinary stones group compared to the controls, respectively (p < 0.05). Routine blood, renal and bladder function tests as well as urinalysis were normal in all children. No urological tumors were detected. No noticeable impact of melamine-related urinary stones on kidney and bladder was found at 4 years follow-up. However, whether or not melamine-related urinary stones had effect on body growth needs follow-up in future.

Toxicity of melamine: the public health concern

Melamine contamination in food has resulted in sickness and deaths of human infants, pets, and farm animals in the past decade. The majority of the victims suffered from acute kidney injury, nephrolithiasis, and urolithiasis. Since then, animal studies have revealed the possible target organs of the melamine toxicity and the extent of the adverse effects of the contaminant. State-of-the-art analytical methods have been developed to achieve the "zero tolerance" aim for such economically motivated adulteration. These studies provide in-depth understanding of the melamine toxicity and promising analytical methods, which can help us safeguard our dairy food source.