Metabonomic study of aristolochic acid-induced nephrotoxicity in rats

Integrating Epigenetics, Proteomics, and Metabolomics to Reveal the Involvement of Wnt/β-Catenin Signaling Pathway in Oridonin-Induced Reproductive Toxicity

Oridonin is the primary active component in the traditional Chinese medicine Rabdosia rubescens, displaying anti-inflammatory, anti-tumor, and antibacterial effects. It is widely employed in clinical therapy for acute and chronic pharyngitis, tonsillitis, as well as bronchitis. Nevertheless, the clinical application of oridonin is significantly restricted due to its reproductive toxicity, with the exact mechanism remaining unclear. The aim of this study was to investigate the mechanism of oridonin-induced damage to HTR-8/SVneo cells. Through the integration of epigenetics, proteomics, and metabolomics methodologies, the mechanisms of oridonin-induced reproductive toxicity were discovered and confirmed through fluorescence imaging, RT-qPCR, and Western blotting. Experimental findings indicated that oridonin altered m6A levels, gene and protein expression levels, along with metabolite levels within the cells. Additionally, oridonin triggered oxidative stress and mitochondrial damage, leading to a notable decrease in WNT6, β-catenin, CLDN1, CCND1, and ZO-1 protein levels. This implied that the inhibition of the Wnt/β-catenin signaling pathway and disruption of tight junction might be attributed to the cytotoxicity induced by oridonin and mitochondrial dysfunction, ultimately resulting in damage to HTR-8/SVneo cells.

Mice kidney biometabolic process analysis after cantharidin exposure using widely-targeted metabolomics combined with network pharmacology

Cantharidin (CTD) is a principal bioactive component of traditional Chinese medicine Mylabris used in cancer treatment. However, CTD clinical application is limited due to nephrotoxicity, and the mechanism is unknown. The present study used widely-targeted metabolomics, network pharmacology, and cell experiments to investigate the nephrotoxicity mechanism after CTD exposure. In mice exposed to CTD, serum creatinine and urea nitrogen levels increased with renal injury. Then, 74 differential metabolites were detected, including 51 up-regulated and 23 down-regulated metabolites classified as amino acids, small peptides, fatty acyl, arachidonic acid metabolite, organic acid, and nucleotides. Sixteen metabolic pathways including tyrosine, sulfur, and pyrimidine metabolism were all disrupted in the kidney. Furthermore, network pharmacology revealed that 258 metabolic targets, and pathway enrichment indicated that CTD could activate oxidative phosphorylation and oxidative stress (OS). Subsequently, HK-2 cell experiments demonstrated that CTD could reduce superoxide dismutase while increasing malondialdehyde levels. In conclusion, after CTD exposure, biometabolic processes may be disrupted with renal injury in mice, resulting in oxidative phosphorylation and OS.

Acute and Subchronic Toxicity Studies of Aristolochic Acid A in Tianfu Broilers

Simple Summary

Aristolochic acid (AA) is a chemical compound present in traditional Chinese medicine, which is widely used for anti-infection, anti-viral and anti-bacterial treatment, as antibiotics were banned in the poultry industry. However, long-term use of this drug in high doses can cause harmful damage to the kidneys of animals. Therefore, in this study, the acute toxicity test and subchronic toxicity test of AA were carried out in order to explore the nephrotoxicity mechanism of AA on Tianfu broilers. In this study, the LD50 of AA to male Tianfu broilers was 14.52 mg/kg. Subchronic exposure to high doses of AA in broilers can cause nephrotoxicity by breaking the redox balance to form oxidative stress, along with promoting apoptosis of renal cells. In conclusion, AA has been found to damage broilers’ kidneys in high doses. This study provides suggestions for the clinical application of traditional Chinese medicine containing AA in the poultry industry.

Abstract

Aristolochic acid (AA) is one of the components of some traditional Chinese medicines, which has high toxic potential in animals, leading to huge economic losses in the breeding industry. The purpose of this study is to evaluate the toxicology of AA on Tianfu broilers through acute and subchronic toxicity tests. The results showed that the median lethal dose of AA to Tianfu broilers was 14.52 mg/kg. After continuous intraperitoneal injection of AA solution (1.452 mg/kg) for 28 days, the swollen and necrotic renal tubular epithelial cells were histologically observed; in addition, blood urea nitrogen (BUN) and creatinine (Cre) were significantly increased, indicating AA could induce serious kidney lesions in broilers. Moreover, the ROS, the apoptosis rate and the depolarization rate of the mitochondrial membrane potential of broilers’ renal cells increased. The results of QRT-PCR showed that AA reduced the mRNA expressions of HO-1, NQO1, Raf-1 and Bcl-2, while the expressions of Bax and Caspase-3 increased, which show that AA aroused oxidative stress and promoted the apoptosis of renal cells. In conclusion, AA has been found to damage broilers’ kidneys by breaking the redox balance to form oxidative stress, along with promoting apoptosis of renal cells.

On-line enrichment and determination of aristolochic acid in medicinal plants using a MOF-based composite monolith as adsorbent

In this study, modified UiO-66-NH₂ and N-methylolacrylamide (NMA) were used as common monomers to prepare a metal organic framework (MOF)-based composite monolith through in-situ polymerization, which was used as a new adsorbent to purify and enrich aristolochic acid-I (AA-I) in medicinal plants. The MOF-based composite monolithic column was characterized by nitrogen adsorption-desorption isotherm, mercury intrusion porosimetry and scanning electron microscopy (SEM). The adsorption ability of MOF-based composite monolith for AA-I was compared with that of the polymer monolith without MOF added. The results proved that the addition of UiO-66-NH₂ can increase both the specific surface area and the permeability of the monolith. Moreover, the adsorption amount of AA-I on the monolith improved. This proposed on-line solid phase extraction (SPE) method showed good linear relationship in the range 0.044 ~ 400 μg/mL with r = 0.9994; the limit of detection (LOD) was 13.08 ng/mL and the limit of quantification (LOQ) was 44.00 ng/mL; the intra-day and inter-day accuracies were less than 0.97%; the inter-column accuracies was less than 6.11%; the recovery was in the range of 91.11%~106.48%. The method was found to be easy, accurate and convenient for on-line enrichment and purification of AA-I in medicinal plants.

In situ metabolomics in nephrotoxicity of aristolochic acids based on air flow-assisted desorption electrospray ionization mass spectrometry imaging

Understanding of the nephrotoxicity induced by drug candidates is vital to drug discovery and development. Herein, an in situ metabolomics method based on air flow-assisted desorption electrospray ionization mass spectrometry imaging (AFADESI-MSI) was established for direct analysis of metabolites in renal tissue sections. This method was subsequently applied to investigate spatially resolved metabolic profile changes in rat kidney after the administration of aristolochic acid I, a known nephrotoxic drug, aimed to discover metabolites associated with nephrotoxicity. As a result, 38 metabolites related to the arginine–creatinine metabolic pathway, the urea cycle, the serine synthesis pathway, metabolism of lipids, choline, histamine, lysine, and adenosine triphosphate were significantly changed in the group treated with aristolochic acid I. These metabolites exhibited a unique distribution in rat kidney and a good spatial match with histopathological renal lesions. This study provides new insights into the mechanisms underlying aristolochic acids nephrotoxicity and demonstrates that AFADESI-MSI-based in situ metabolomics is a promising technique for investigation of the molecular mechanism of drug toxicity.

Aristolochic Acid-Induced Genotoxicity and Toxicogenomic Changes in Rodents

Aristolochic acid (AA) is a group of structurally related nitrophenanthrene carboxylic acids found in many plants that are widely used by many cultures as traditional herbal medicines. AA is a causative agent for Chinese herbs nephropathy, a term replaced later by AA nephropathy. Evidence indicates that AA is nephrotoxic, genotoxic, and carcinogenic in humans; and it also induces tumors in the forestomach, kidney, renal pelvis, urinary bladder, and lung of rats and mice. Therefore, plants containing AA have been classified as carcinogenic to humans (Group 1) by the International Agency for Research on Cancer. In our laboratories, we have conducted a series of genotoxicity and toxicogenomic studies in the rats exposed to AA of 0.1–10 mg/kg for 12 weeks. Our results demonstrated that AA treatments induced DNA adducts and mutations in the kidney, liver, and spleen of rats, as well as significant alteration of gene expression in both its target and nontarget tissues. AA treatments altered mutagenesis- or carcinogenesis-related microRNA expression in rat kidney and resulted in significant changes in protein expression profiling. We also applied benchmark dose (BMD) modeling to the 3-month AA-induced genotoxicity data. The obtained BMDL₁₀ (the lower 95% confidence interval of the BMD₁₀ that is a 10% increase over the background level) for AA-induced mutations in the kidney of rats was about 7 μg/kg body weight per day. This review constitutes an overview of our investigations on AA-induced genotoxicity and toxicogenomic changes including gene expression, microRNA expression, and proteomics; and presents updated information focused on AA-induced genotoxicity in rodents.

Toxicity and Its Mechanism Study of Arecae semen Aqueous Extract in Wistar Rats by UPLC-HDMS-Based Serum Metabolomics

Background

Arecae semen (AS) is officially recorded in Chinese Pharmacopoeia and it is known for its multiple functions, including antidepressive, antioxidant, anti-inflammatory, and cholesterol-lowering effects, which have been confirmed by modern pharmacological study. Previous study in our laboratory showed that long-term oral administration of Arecae semen (AS) is officially recorded in Chinese Pharmacopoeia and it is known for its multiple functions, including antidepressive, antioxidant, anti-inflammatory, and cholesterol-lowering effects, which have been confirmed by modern pharmacological study. Previous study in our laboratory showed that long-term oral administration of Hypothesis. The aim of this work was to characterize the metabolome, evaluate the metabolic changes, and study the mechanisms of the toxicity induced by different treatment doses of ASAE via metabolomics.

Methods

Wistar rats were administered orally two different doses of ASAE (1500 and 4500 mg/kg/d) for 30 days. The investigation was carried out to evaluate the safety of ASAE. And, the UPLC-HDMS-based serum metabolomics in conjunction with multivariate statistical techniques was applied to investigate the serum metabolite profile and potential markers of toxicity induced by different doses of ASAE.

Results

Coupled with blood biochemistry and histopathology results, the significant difference in metabolic profiling was observed between 1500 and 4500 mg/kg/d dosages of ASAE-treated rats and normal rats by using pattern recognition analysis, indicating that changes in serum metabolites must have occurred. Some significant changed metabolites such as arachidonic acid, linoleic acid, stearic acid, and LPC (18 : 1) have been found and identified. These biochemical changes in serum metabolites are related to the perturbation of linoleic acid metabolism, arachidonic acid metabolism, glycerophospholipid metabolism, and purine metabolism, which may be helpful to further understand the cardiotoxicity and neurotoxicity of ASAE.

Conclusion

The study shows that the metabolomic method may be a valuable tool for studying the essence of toxicity induced by traditional Chinese medicine.

The footprints of mitochondrial impairment and cellular energy crisis in the pathogenesis of xenobiotics-induced nephrotoxicity, serum electrolytes imbalance, and Fanconi's syndrome: A comprehensive review

Fanconi's Syndrome (FS) is a disorder characterized by impaired renal proximal tubule function. FS is associated with a vast defect in the renal reabsorption of several chemicals. Inherited and/or acquired conditions seem to be connected with FS. Several xenobiotics including many pharmaceuticals are capable of inducing FS and nephrotoxicity. Although the pathological state of FS is well described, the exact underlying etiology and cellular mechanism(s) of xenobiotics-induced nephrotoxicity, serum electrolytes imbalance, and FS are not elucidated. Constant and high dependence of the renal reabsorption process to energy (ATP) makes mitochondrial dysfunction as a pivotal mechanism which could be involved in the pathogenesis of FS. The current review focuses on the footprints of mitochondrial impairment in the etiology of xenobiotics-induced FS. Moreover, the importance of mitochondria protecting agents and their preventive/therapeutic capability against FS is highlighted. The information collected in this review may provide significant clues to new therapeutic interventions aimed at minimizing xenobiotics-induced renal injury, serum electrolytes imbalance, and FS.

Safety investigation of Pulsatilla chinensis saponins from chronic metabonomic study of serum biomedical changes in oral treated rat

ETHNOPHARMACOLOGICAL RELEVANCE

Pulsatilla chinensis (Bunge) Regel is a valuable traditional Chinese medicine (TCM) which is widely used for the treatment of schistosomiasis, inflammatory, bacterial infections. In recent years, P chinensis has been reported to exhibit antitumor activities. However, the mechanisms underlying its toxic effects remain largely unresolved. This paper is designed to investigate the damage of long-term oral P. chinensis saponins (PRS) and to explore its potential damage mechanisms by serum metabonomics approach.

MATERIALS AND METHODS

The serum samples from control and PRS treated rats were analyzed by ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) in positive ionization mode and negative ionization mode. Liver function index of ALT, AST and ALP, blood biochemistry and biomarkers were examined to identify specific changes of injury. Acquired data were subjected to principal component analysis (PCA) for differentiating the control and PRS treated groups. Then, serum metabolic profiling was analyzed and pathway analysis performed on the biomarkers reversed after PRS treated and further integration of metabolic networks.

RESULTS

The results suggested that serum liver function indexes of ALT had significantly changed and stage increased. AST, ALP detection content show volatility changes. Changes in the 15 biomarkers found in the serum, such as acetaminophen glucuronide, 9 E, 11 E-linoleic acid, chenodeoxycholic acid, monoacylglycerides, sphingomyelin (SM), 7-ketodeoxycholic acid and 12-keto-deoxycholic acid, which were closely related to changes in liver injury. It could be seen clearly that with the change of the dosing time, the biomarkers in the serum have undergone obvious, regular and progressive changes through the score plot and corresponding loading plot. The underlying regulations of PRS-perturbed metabolic pathways were discussed according to the identified metabolites.

CONCLUSION

The present study proves the potential of UPLC-QTOF-MS based metabonomics in mapping metabolic response. Long-term oral administration of P. chinensis saponins can cause chronic liver injury, and its safety needs further attention. It is of great significance in safeguarding human health to explore the damage mechanism of Pulsatilla chinensis saponins on liver by serum metabolomics.

Aristolochic acid I determine the phenotype and activation of macrophages in acute and chronic kidney disease

Acute and chronic kidney injuries are multifactorial traits that involve various risk factors. Experimental animal models are crucial to unravel important aspects of injury and its pathophysiological mechanisms. Translating knowledge obtained from experimental approaches into clinically useful information is difficult; therefore, significant attention needs to be paid to experimental procedures that mimic human disease. Herein, we compared aristolochic acid I (AAI) acute and chronic kidney injury model with unilateral ischemic-reperfusion injury (uIRI), cisplatin (CP)- or folic acid (FA)-induced renal damage. The administration of AAI showed significant changes in serum creatinine and BUN upon CKD. The number of neutrophils and macrophages were highly increased as well as AAI-induced CKD characterized by loss of tubular epithelial cells and fibrosis. The in vitro and in vivo data indicated that macrophages play an important role in the pathogenesis of AA-induced nephropathy (AAN) associated with an excessive macrophage accumulation and an alternative activated macrophage phenotype. Taken together, we conclude that AA-induced injury represents a suitable and relatively easy model to induce acute and chronic kidney injury. Moreover, our data indicate that this model is appropriate and superior to study detailed questions associated with renal macrophage phenotypes.

Cardioprotective effects and mechanism of Radix Salviae miltiorrhizae and Lignum Dalbergiae odoriferae on rat myocardial ischemia/reperfusion injury

Radix Salviae miltiorrhizae (SM) and Lignum Dalbergiae odoriferae (DO) are traditional Chinese medicinal herbs used to treat ischemic heart disease and other cardiovascular diseases; however, to the best of our knowledge, there are currently few studies regarding their effects. The present study aimed to investigate the cardioprotective effects of SM and DO during myocardial ischemia/reperfusion (MI/R) injury in rats, and explore the molecular mechanisms that underlie their actions. In the present study, Sprague-Dawley rats were pretreated with SM, the aqueous extract of DO (DOA) and the volatile oil of DO (DOO), either as a monotherapy or in combination for 7 days. Subsequently, the rats were subjected to 30 min of ischemia followed by 180 min of reperfusion. Traditional pharmacodynamic evaluation and metabonomics based on gas chromatography/time-of-flight mass spectrometry were used to identify the therapeutic effects of these traditional Chinese medicines. The results revealed that SM, DOA and DOO monotherapies ameliorated cardiac function, and this effect was strengthened further when used in combined therapies. Among the combined treatments, SM + DOO exhibited the greatest potential (P<0.05) to improve electrocardiogram results and heart rate, reduce the heart weight index and myocardial infarct size, and decrease the levels of creatine kinase-MB and lactate dehydrogenase. In addition, metabonomics-based findings, including the principal component analysis and partial least squares discriminant analysis score plot of the metabolic state in rat serum, provided confirmation for the aforementioned results, verifying that SM + DOO exerted synergistic therapeutic efficacies to exhibit a greater effect on rats with MI/R injury when compared with the other pretreatment groups. Furthermore, the most effective duration of SM + DOO treatment was 30 min and the least effective duration was 180 min. Treatment with SM + DOO also significantly (P<0.01) reduced the number of terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling-positive cells, tumor necrosis factor-α andinterleukin-6 expression, and malondialdehyde content, and increased the serum and tissue activity of superoxide dismutase. These results indicated that the combined effects of SM + DOO may be more effective compared with the single pretreatments against MI/R injury in rats. This effect may be achieved partly through anti-apoptotic, antioxidant and anti-inflammatory activities. Therefore, SM + DOO may be considered an effective and promising novel strategy for the prophylaxis and treatment of ischemic heart disease.

Predicting points of departure for risk assessment based on in vitro cytotoxicity data and physiologically based kinetic (PBK) modeling: The case of kidney toxicity induced by aristolochic acid I

Aristolochic acids are naturally occurring nephrotoxins. This study aims to investigate whether physiologically based kinetic (PBK) model-based reverse dosimetry could convert in vitro concentration-response curves of aristolochic acid I (AAI) to in vivo dose response-curves for nephrotoxicity in rat, mouse and human. To achieve this extrapolation, PBK models were developed for AAI in these different species. Subsequently, concentration-response curves obtained from in vitro cytotoxicity models were translated to in vivo dose-response curves using PBK model-based reverse dosimetry. From the predicted in vivo dose-response curves, points of departure (PODs) for risk assessment could be derived. The PBK models elucidated species differences in the kinetics of AAI with the overall catalytic efficiency for metabolic conversion of AAI to aristolochic acid Ia (AAIa) being 2-fold higher for rat and 64-fold higher for mouse than human. Results show that the predicted PODs generally fall within the range of PODs derived from the available in vivo studies. This study provides proof of principle for a new method to predict a POD for in vivo nephrotoxicity by integrating in vitro toxicity testing with in silico PBK model-based reverse dosimetry.

The Progress of Metabolomics Study in Traditional Chinese Medicine Research

Traditional Chinese medicine (TCM) has played important roles in health protection and disease treatment for thousands of years in China and has gained the gradual acceptance of the international community. However, many intricate issues, which cannot be explained by traditional methods, still remain, thus, new ideas and technologies are needed. As an emerging system biology technology, the holistic view adopted by metabolomics is similar to that of TCM, which allows us to investigate TCM with complicated conditions and multiple factors in depth. In this paper, we tried to give a timely and comprehensive update about the methodology progression of metabolomics, as well as its applications, in different fields of TCM studies including quality control, processing, safety and efficacy evaluation. The herbs investigated by metabolomics were selected for detailed examination, including Anemarrhena asphodeloides Bunge, Atractylodes macrocephala Kidd, Pinellia ternate, etc.; furthermore, some valuable results have been obtained and summarized. In conclusion, although the study of metabolomics is at the early phase and requires further scrutiny and validation, it still provides bright prospects to dissect the synergistic action of multiple components from TCM. Overall, with the further development of analytical techniques, especially multi-analysis techniques, we expect that metabolomics will greatly promote TCM research and the establishment of international standards, which is beneficial to TCM modernization.

Metabolomics and its application to the evaluation of the efficacy and toxicity of traditional Chinese herb medicines

Traditional Chinese herb medicines (TCHMs) have been used in the treatment of a variety of diseases for thousands of years in Asian countries. The active components of TCHMs usually exert combined synergistic therapeutic effects on multiple targets, but with less potential therapeutic effect based on routine indices than Western drugs. These complex effects make the assessment of the efficacy of TCHMs and the clarification of their underlying mechanisms very challenging, and therefore hinder their wider application and acceptance. Metabolomics is a crucial part of systems biology. It allows the quantitative measurement of large numbers of the low-molecular endogenous metabolites involved in metabolic pathways, and thus reflects the fundamental metabolism status of the body. Recently, dozens of metabolomic studies have been devoted to prove the efficacy/safety, explore the underlying mechanisms, and identify the potential biomarkers to access the action targets of TCHMs, with fruitful results. This article presents an overview of these studies, focusing on the progress made in exploring the pharmacology and toxicology of various herbal medicines.

"Omics" in pharmaceutical research: overview, applications, challenges, and future perspectives

In the post-genomic era, biological studies are characterized by the rapid development and wide application of a series of "omics" technologies, including genomics, proteomics, metabolomics, transcriptomics, lipidomics, cytomics, metallomics, ionomics, interactomics, and phenomics. These "omics" are often based on global analyses of biological samples using high through-put analytical approaches and bioinformatics and may provide new insights into biological phenomena. In this paper, the development and advances in these omics made in the past decades are reviewed, especially genomics, transcriptomics, proteomics and metabolomics; the applications of omics technologies in pharmaceutical research are then summarized in the fields of drug target discovery, toxicity evaluation, personalized medicine, and traditional Chinese medicine; and finally, the limitations of omics are discussed, along with the future challenges associated with the multi-omics data processing, dynamics omics analysis, and analytical approaches, as well as amenable solutions and future prospects.

Application of metabonomics in research of inflammatory bowel disease

Inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohn's disease (CD), is a chronic non-specific inflammatory disorder of the gastrointestinal tract. The etiology and pathogenesis of IBD are still not entirely understood today and are thought to be caused by the interaction of multiple factors, including environmental, genetic, infectious and immune factors. The lack of typical clinical features also leads to a difficult diagnosis of IBD. In recent years, metabonomics is becoming a very important way to find biomarkers and investigate disease mechanisms. In this paper we review the main technologies of metabonomics and their present application in IBD.

Application of morbid animal model in drug safety evaluation of traditional Chinese medicine

During thousands of years of clinical validation and practice, the efficacy and safety of traditional Chinese medicine (TCM) have been widely recognized in the prevention and treatment for various diseases. However, further toxicology research of TCM new drugs is still necessary.

Metabolomics in nephrotoxicity

Nephrotoxicity or renal toxicity can be a result of hemodynamic changes, direct injury to cells and tissue, inflammatory tissue injury, and/or obstruction of renal excretion. Nephrotoxicity is frequently induced by a wide spectrum of therapeutic drugs and environ mental pollutants. Knowledge of the complex molecular and pathophysiologic mechanisms leading to nephrotoxicity remains limited, in part, by research that historically focused on single or relatively few risk markers. As such, current kidney injury biomarkers are inadequate in terms of sensitivity and specificity. In contrast, metabolomics enables screening of a vast array of metabolites simultaneously using NMR and MS to assess their role in nephrotoxicity development and progression. A more comprehensive understanding of these biochemical pathways would also provide valuable insight to disease mechanisms critical for drug development and treatment.

Progress and perspectives of biomarker discovery in Chinese medicine research

Biomarker discovery in Chinese medicine (CM) has recently attracted a great deal of attention, owing to the promise of high-throughput technologies development and the potential of Chinese herbal medicine. Furthermore, it seems that pattern classification in CM might be serving as inspirational analogy and a practical guide, which might contribute to biomarkers discovery rather than just being used as diagnostic method. Although much work is still needed to identify markers, efforts are now being directed towards discovering biomarkers or biomarkers based network that could target herbal formulae. In this article, we review progress in biomarker discovery development, discuss current biomarker discovery in CM highlighting challenges and opportunities of pattern classification and presenting a perspective of the future integrative modeling approaches as an emerging trend in biomarker discovery.

Evaluating weight of evidence in the mystery of Balkan endemic nephropathy

Balkan endemic nephropathy (BEN) is a chronic, progressive wasting disease of the kidneys, endemic in certain rural regions of the Balkan nations Croatia, Serbia, Bulgaria, and Romania. It is irreversible and ultimately fatal. Though this disease was first described in the 1950s, its causes have been a mystery and a source of much academic and clinical contention. Possible etiologic agents that have been explored include exposure to metals and metalloids, viruses and bacteria, and the dietary toxins aristolochic acid (AA) and ochratoxin A (OTA). AA is a toxin produced by weeds of the genus Aristolochia, common in Balkan wheat fields. Aristolochia seeds may intermingle with harvested grains and thus inadvertently enter human diets. OTA is a mycotoxin (fungal toxin) common in many foods, including cereal grains. In this study, we analyzed the weight of evidence for each of the suspected causes of BEN using the Bradford Hill criteria (BHC): nine conditions that determine weight of evidence for a causal relationship between an agent and a disease. Each agent postulated to cause BEN was evaluated using the nine criteria, and for each criterion was given a rating based on the strength of the association between exposure to the substance and BEN. From the overall available scientific evidence for each of these suspected risk factors, AA is the agent with the greatest weight of evidence in causing BEN. We describe other methods for testing causality from epidemiological studies, which support this conclusion of AA causing BEN.

Novel methodologies in analysis of small molecule biomarkers and living cells

Enzyme-linked immuno-sorbent assay (ELISA) is widely used for biomarker detection. A good biomarker can distinguish patients from healthy or benign diseases. However, the ELISA method is not suitable for small molecule or trace substance detection. Along with the development of new technologies, an increasing level of biomaterials, especially small molecules, will be identified as novel biomarkers. Quantitative immuno-PCR, chromatography-mass spectrometry, and nucleic acid aptamer are emerging methodologies for detection of small molecule biomarkers, even in living cells. In this review, we focus on these novel technologies and their potential for small molecule biomarkers and living cell analysis.

Metabonomic study on the antidepressant-like effects of banxia houpu decoction and its action mechanism

The aim of this study was to establish an experimental model for metabonomic profiles of the rat's brain and then to investigate the antidepressant effect of Banxia Houpu decoction (BHD) and its possible mechanisms. Behavioral research and metabonomics method based on UPLC-MS were used to assess the efficacy of different fractions of BHD on chronic unpredictable mild stress (CUMS) model of depression. There was a significant difference between the BHD group and the model group. Eight endogenous metabolites, which are contributing to the separation of the model group and control group, were detected, while BHD group regulated the perturbed metabolites showing that there is a tendency of recovery compared to control group. Therefore, we think that those potential metabolite biomarkers have some relationship with BHD's antidepression effect. This work appraised the antidepressant effect of Banxia Houpu decoction as well as revealing a metabonomics method, a valuable parameter in the TCM research.

General toxicity of Pinellia ternata (Thunb.) Berit. in rat: a metabonomic method for profiling of serum metabolic changes

ETHNOPHARMACOLOGICAL RELEVANCE

BX is a traditional Chinese medicine (TCM) from the plant Pinellia ternata(Thunb.) Berit. It has been traditionally used to treat cough, vomiting, infection and inflammation. Despite of its potentially clinical utility, it also has many side effects and toxicity.

AIM OF THE STUDY

We propose here an ultra performance liquid chromatography coupled with quadrupole time-of-fight mass spectrometry (UPLC Q-TOF/MS) metabonomics approach to elucidate the toxicity in rats induced by orally administered BX in multiple organs including the kidney, liver, and heart.

MATERIALS AND METHODS

Serum samples were collected from Sprague-Dawley male rats exposed to BX (6g/kg/day, n=10) and healthy controls (n=10) at the 48 h, 144 h, 240 h, and 336 h postdose for LC/MS analyses. Through principal component analysis and orthogonal partial least squares-discriminant analysis of the integrated serum MS data, we distinguished the BX group from the healthy control group and identified the differential metabolites and pertinent altered biological pathways in response to the herbal toxin. The liver, kidney, heart were assessed using conventional histopathological examinations at the end point of the experiment. The serum samples at the 336 h postdose were assessed using biochemistry test.

RESULTS

Significant differences in the serum levels of phospholipids, amino acids, L-carnitine and L-acetylcarnitine were observed in BX-induced rats, indicating the perturbations of phospholipid metabolism, amino acid metabolism and carnitine metabolism in BX-induced rats.

CONCLUSIONS

In the paper, we used metabonomics approach to study the toxicity of BX for the first time. With blood biochemistry, histopathological examinations and metabonomics methods, we validated that oral administration of crude BX caused no obvious liver and kidney toxicity in SD rats. BX may possess certain cardio toxicity in SD rats. The metabolism changes suggested that metabonomic approach was a promising tool to study and diagnose TCM-induced toxicity.

Urinary metabonomic study of the surface layer of Poria cocos as an effective treatment for chronic renal injury in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Poria cocos Wolf (Polyporaceae) is a well-known medicinal fungus. The epidermis of the sclerotia ("Fu-Ling-Pi" in Chinese) is used as a diuretic and traditionally used for promoting urination and reduce edema.

AIM OF THE STUDY

Traditional Chinese medicines (TCM) treat many diseases through multi-components, multi-ways and multi-targets. However, the molecular mechanisms of TCM are not yet well understood. In the present work, ultra performance liquid chromatography-based metabonomics analysis was applied to investigate the urinary metabolite profiling of the renoprotective effect of FLP on adenine-induced chronic kidney disease (CKD) rat model and involved possible mechanism.

MATERIAL AND METHODS

A metabonomic approach based on ultra performance liquid chromatography coupled with quadrupole time-of-flight high-sensitivity mass spectrometry and a novel mass spectrometry(Elevated Energy) data collection technique was developed. The resulting dataset was analyzed by principal component analysis and partial least squares discriminant analysis. The identification of all potential biomarkers was performed using reference standard by comparing their mass spectra, MS(E) fragments information, isotopic pattern and MassLynx i-FIT algorithm.

RESULTS

By partial least squares-discriminate analysis, 15 biomarkers in rat urine were identified and 11 of them were related to the pathway of adenine metabolism and amino acid metabolism. Among these biomarkers, eight biomarkers like adenine, L-acetylcarnitine, 8-hydroxyadenine, hypoxanthine, creatine, methionine, phytosphingosine and phenylalanine were reversed to the control level in FLP-treated group and six biomarkers like 2,8-dihydroxyadenine, indole-3-carboxylic acid, 3-methyldioxyindole, ethyl-N2-acetyl-L-argininate, 3-O-methyldopa and xanthurenic acid were reversed to high control group by FLP, which indicates that the urinary metabolic pattern significantly changed after FLP treatment.

CONCLUSIONS

Our study indicates that FLP treatment can ameliorate CKD by intervening in some dominating metabolic pathways, such as adenine metabolism and amino acid metabolism. The metabonomic results not only supplied a systematic view of the development and progression of CKD and mechanism studies of FLP but also provided the theoretical basis for the prevention or treatment of CKD.

UPLC Q-TOF/MS-Based Metabolic Profiling of Urine Reveals the Novel Antipyretic Mechanisms of Qingkailing Injection in a Rat Model of Yeast-Induced Pyrexia

Fever is one of the most common clinical symptoms of many diseases. Qingkailing (QKL) injection is widely used in China as a clinical emergency medicine due to its good antipyretic effects. It is a herbal formula which is composed by eight kinds of traditional Chinese medicines (TCM). As a kind of typical multiple constituents and multiple actions of TCM, it is very difficult to elaborate the antipyretic mechanism by conventional pharmacological method. Metabonomics technique provides beneficial tool for this challenge. In this study, an ultra performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC Q-TOF/MS) metabonomics method was developed to explore the changing process of biochemical substances in rats of yeast-induced pyrexia. Partial least squares discriminate analysis (PLS-DA) was used to distinguish the normal control group, the pyrexia model group, and the pyrexia model group treated by QKL injection. The potential biomarkers related to pyrexia were confirmed and identified. MetPA was used to find the possible metabolic pathways. The results indicated that the antipyretic effect of QKL injection on yeast-induced pyrexia rats was performed by repairing the perturbed metabolism of amino acids.

Metabolomic analysis of complex chinese remedies: examples of induced nephrotoxicity in the mouse from a series of remedies containing aristolochic Acid

Aristolochic acid nephropathy is caused by aristolochic acid (AA) and AA-containing herbs. In traditional Chinese medicine, a principle called “Jun-Chen-Zou-Shi” may be utilized to construct a remedial herbal formula that attempts to mitigate the toxicity of the main ingredient. This study used Bu-Fei-A-Jiao-Tang (BFAJT) to test if the compound remedy based on a principle of “Jun-Chen-Zou-Shi” can decrease the toxicity of AA-containing herbs. We compared the three toxicities of AA standard, Madouling (an Aristolochia herb), and a herbal formula BFAJT. AA standard was given for BALB/c mice at a dose of 5 mg/kg bw/day or 7.5 mg/kg bw/day for 10 days. Madouling and BFAJT were given at an equivalence of AA 0.5 mg/kg bw/day for 21 days. Nephrotoxicity was evaluated by metabolomics and histopathology. The urinary metabolomics profiles were characterized by ¹H NMR spectroscopy. The spectral data was analyzed with partial least squares discriminant analysis, and the significant differential metabolites between groups were identified. The result showed different degrees of acute renal tubular injuries, and metabolomics analysis found that the kidney injuries were focused in proximal renal tubules. Both metabolomics and pathological studies revealed that AA standard, Madouling, and BFAJT were all nephrotoxicants. The compositions of the compound remedy did not diminish the nephrotoxicity caused by AA.

A serum metabolomic investigation on lipoprotein lipase-deficient mice with hyperlipidemic pancreatitis using gas chromatography/mass spectrometry

Hypertriglyceridemia (HTG) is often associated with acute pancreatitis. The relationship between these diseases and the role that hypertriglyceridemia plays in acute pancreatitis pathogenesis remains to be elucidated. In the present study, in order to investigate the mechanisms of hyper-lipidemic acute pancreatitis (HLP), we established an animal model using lipoprotein lipase (LPL)-deficient heterozygous mice injected with caerulein. Susceptibility to pancreatitis in LPL-deficient heterozygous mice was compared with that of wild-type mice after intraperitoneal (i.p.) injections of caerulein by determining amylase release and pancreatic pathological scores. Furthermore, serum metabolome was detected through chemical derivatization followed by gas chromatography/mass spectrometry (GC/MS). GC/MS data were analyzed by orthogonal-projection to latent structures-discriminant analysis (OPLS-DA). Caerulein induced increased levels of serum amylase and more severe pancreatic inflammation in LPL-deficient mice compared to wild-type mice. HLP was discriminated more accurately from healthy controls by the metabolites, including valine, leucine and citrate. The metabolites included valine, leucine, citrate, malic acid, proline, tetradecanoic acid (14:0), glutamine and oleic acid (18:1). Changes in energy, fat and amino acid metabolism were also evident. In conclusion, LPL-deficient heterozygous mice with hypertriglyceridemia (HTG) exhibited enhanced susceptibility to acute pancreatitis. GC/MS data revealed differences between healthy and HLP mice. Therefore, this technique is novel and a useful tool for the study of the HLP pathogenetic mechanism.

Gut microbiomes of Malawian twin pairs discordant for kwashiorkor

Kwashiorkor, an enigmatic form of severe acute malnutrition, is the consequence of inadequate nutrient intake plus additional environmental insults. To investigate the role of the gut microbiome, we studied 317 Malawian twin pairs during the first 3 years of life. During this time, half of the twin pairs remained well nourished, whereas 43% became discordant, and 7% manifested concordance for acute malnutrition. Both children in twin pairs discordant for kwashiorkor were treated with a peanut-based, ready-to-use therapeutic food (RUTF). Time-series metagenomic studies revealed that RUTF produced a transient maturation of metabolic functions in kwashiorkor gut microbiomes that regressed when administration of RUTF was stopped. Previously frozen fecal communities from several discordant pairs were each transplanted into gnotobiotic mice. The combination of Malawian diet and kwashiorkor microbiome produced marked weight loss in recipient mice, accompanied by perturbations in amino acid, carbohydrate, and intermediary metabolism that were only transiently ameliorated with RUTF. These findings implicate the gut microbiome as a causal factor in kwashiorkor.

Effect of 20(S)-ginsenoside Rg3 on streptozotocin-induced experimental type 2 diabetic rats: a urinary metabonomics study by rapid-resolution liquid chromatography/mass spectrometry

RATIONALE

20(S)-ginsenoside Rg3 is an active component of Panax ginseng. It is known that 20(S)-ginsenoside Rg3 has a protective effect against hyperglycemia, obesity and diabetes in vivo, but the precise mechanisms of these actions have not yet been entirely elucidated.

METHODS

A urinary metabonomics method based on rapid-resolution liquid chromatography/mass spectrometry (RRLC/MS) was developed to investigate the effect of 20(S)-ginsenoside Rg3 on type 2 diabetic rats.

RESULTS

With multivariate statistical analysis, a clear separation between type 2 diabetic rats and those treated with 20(S)-ginsenoside Rg3 was achieved. Six potential biomarkers were found and identified.

CONCLUSIONS

This work shows that the mechanism of the effect of 20(S)-ginsenoside Rg3 on type 2 diabetes may be involved with the regulation of nucleic acid metabolism, energy metabolism and gut flora metabolism.

Review of current and "omics" methods for assessing the toxicity (genotoxicity, teratogenicity and nephrotoxicity) of herbal medicines and mushrooms

ETHNOPHARMACOLOGICAL RELEVANCE

The increasing use of traditional herbal medicines around the world requires more scientific evidence for their putative harmlessness. To this end, a plethora of methods exist, more or less satisfying. In this post-genome era, recent reviews are however scarce, not only on the use of new "omics" methods (transcriptomics, proteomics, metabonomics) for genotoxicity, teratogenicity, and nephrotoxicity assessment, but also on conventional ones.

METHODS

The present work aims (i) to review conventional methods used to assess genotoxicity, teratogenicity and nephrotoxicity of medicinal plants and mushrooms; (ii) to report recent progress in the use of "omics" technologies in this field; (iii) to underline advantages and limitations of promising methods; and lastly (iv) to suggest ways whereby the genotoxicity, teratogenicity, and nephrotoxicity assessment of traditional herbal medicines could be more predictive.

RESULTS

Literature and safety reports show that structural alerts, in silico and classical in vitro and in vivo predictive methods are often used. The current trend to develop "omics" technologies to assess genotoxicity, teratogenicity and nephrotoxicity is promising but most often relies on methods that are still not standardized and validated.

CONCLUSION

Hence, it is critical that toxicologists in industry, regulatory agencies and academic institutions develop a consensus, based on rigorous methods, about the reliability and interpretation of endpoints. It will also be important to regulate the integration of conventional methods for toxicity assessments with new "omics" technologies.

Urinary metabonomics study on biochemical changes in an experimental model of chronic renal failure by adenine based on UPLC Q-TOF/MS

BACKGROUND

Chronic renal failure (CRF) is a serious clinical symptom, occurring as the end result of all kinds of chronic kidney disease and its pathophysiological mechanism is not yet well understood. We investigated the metabolic profiling of urine samples from CRF model rats to find potential disease biomarkers and research pathology of CRF.

METHODS

An animal model of CRF was produced by adenine. Metabolic profiling of the urine was performed by using ultra performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC Q-TOF/MS). Acquired data were subjected to principal component analysis (PCA) for differentiating the CRF and the normal control groups. Potential biomarkers were screened by using S-plot and were identified by the accurate mass, isotopic pattern and MS(E) fragments information obtained from UPLC Q-TOF/MS analysis.

RESULTS

12 metabolites in urine were identified as potential biomarkers. Adenine-induced CRF rats were characterized by the increase of phytosphingosine, adrenosterone, tryptophan, 2,8-dihydroxyadenine, creatinine, and dihydrosphingosine together with the decrease of N-acetylleucine, 3-O-methyldopa, ethyl-N2-acetyl-L-argininate, dopamine, phenylalanine and kynurenic acid in urine. The altered metabolites demonstrated perturbations of amino acids metabolism, phospholipids metabolism and creatinine metabolism in CRF rats.

CONCLUSION

This work shows that metabonomics method is a valuable tool in CRF mechanism study and assists in clinical diagnosis of CRF.