Determination of 12 potential nephrotoxicity biomarkers in rat serum and urine by liquid chromatography with mass spectrometry and its application to renal failure induced by Semen Strychni

Multi-residue screening of pesticides in Panax Ginseng C. A. Meyer by ultra-high-performance liquid chromatography with quadrupole time-of-flight mass spectrometry

In this study, an efficient screening method based on a modified quick, easy, cheap, effective, rugged, and safe extraction method combined with ultra-high-performance liquid chromatography coupled to tandem quadrupole time-of-flight mass spectrometry was established for the determination of 90 pesticides residues in Panax Ginseng. The accuracy of the method was then verified by analyzing the false positive rate and the screening detection limit in Ginseng. The results revealed that the screening detection limit of 33 of 90 pesticide residues were 0.01mg·kg^-1 , 22 species were 0.05 mg·kg^-1 , 11 species were 0.10 mg·kg^-1 , 8 species were 0.20 mg·kg^-1 , and another 16 species were greater than 0.20 mg·kg^-1 . A total of 73 pesticides were ultimately suitable to be practically applied for rapid analysis of pesticide residues in Ginseng. Finally, the established method was used to analyze the pesticide residues in 35 Ginseng samples available on the market. And the residual of Dimethomorph, Azoxystrobin, Tebuconazole, Pyraclostrobin was relatively severe in Ginseng samples. This work expanded the range of pesticides detected and provided a rapid, effective method for pesticides screening in Ginseng. This article is protected by copyright. All rights reserved.

Investigation of the detoxification effect of licorice on Semen Strychni-induced acute toxicity in rats using a HPLC-Q-TOF/MS-based metabolomics approach

Semen Strychni, a traditional Chinese medicine (TCM), has been widely used to treat paraplegia, facial nerve palsy and myasthenia gravis. However, its clinical application is greatly limited due to its fatal toxicity. To investigate the acute toxicity of Semen Strychni and the detoxification effect of licorice, a high-performance liquid chromatography tandem quadrupole time-of-flight mass spectrometry (HPLC-Q-TOF/MS) based urinary metabolomics method was developed in this study. After intraperitoneal injection to rats with Semen Strychni extract, the serum biochemical indexes were changed significantly, the liver and kidney showed severe necrosis and edema. Then the poisoned rat model was subsequently used for metabolomics research. Through principal component analysis (PCA) and orthogonal partial least squares-discriminant analysis (OPLS-DA), we finally identified 19 endogenous differential metabolites involved in amino acid metabolism, glycerophospholipid metabolism, tricarboxylic acid (TCA) cycle, oxidative stress and energy metabolism. In addition, 4 exogenous compounds from Semen Strychni (3 prototypes and 1 metabolite) were also identified in the present study. Results showed that the alterations of 23 compounds caused by Semen Strychni were significantly reversed after licorice treatment, which indicated that restoring the endogenous metabolic disorder and accelerating the metabolism of the main toxic components might be the possible detoxification mechanisms of licorice. This study may provide an integral understanding for the acute toxicity of Semen Strychni and the detoxification effect of licorice, thereby contributing to the clinical use of Semen Strychni and licorice.

The hepatoprotective effect and mechanism of lotus leaf on liver injury induced by Genkwa Flos

OBJECTIVES

As a traditional Chinese medicine, lotus leaf was reported to have significant hepatoprotective effect. To explore the hepatoprotective mechanism of lotus leaf, a rapid and reliable UPLC-MS/MS method was conducted to simultaneously determine six specific endogenous substances including 5-oxoproline, phenylalanine, tryptophan, C₁₈ -phytosphingosine, lysophosphatidylcholine (16 : 0) and lysophosphatidylcholine (18 : 1).

METHODS

With the help of HPLC-FT-ICR-MS, the chemical constituents of louts leaf extract were elucidated. By observing histopathological changes and determining hepatotoxicity-related biochemical indicators, rat model of liver injury was developed and the hepatoprotective effect of lotus leaf was verified. With the developed UPLC-MS/MS method, six endogenous metabolites related to hepatotoxicity were monitored to investigate the hepatoprotective mechanism of lotus leaf.

KEY FINDINGS

In the qualitative analysis, a total of twenty compounds including ten flavonoids, nine alkaloids and one proanthocyanidin were identified. Based on the results of determining six endogenous metabolites related to hepatotoxicity, it was predicted that the hepatoprotective mechanism of lotus leaf might be related to glutathione metabolism, phenylalanine metabolism, tryptophan metabolism, sphingolipid metabolism and phospholipid metabolism.

CONCLUSIONS

This study could be a meaningful investigation to provide mechanistic insights into the hepatoprotective effect of lotus leaf and further lay a theoretical basis for the clinical application of lotus leaf.

Guanidinoacetic acid deficiency: a new entity in clinical medicine?

Guanidinoacetic acid (GAA, also known as glycocyamine or betacyamine) is a naturally-occurring derivative of glycine and a direct metabolic precursor of creatine, a key player in high-phosphate cellular bioenergetics. GAA is found in human serum and urine, with circulating GAA likely reflects an equilibrium between its endogenous production and utilization/excretion. GAA deficiency (as indicated by low serum GAA) has been reported in various conditions yet this intriguing clinical entity appears to be poorly characterized as yet, either as a primary deficit or a sequel of secondary disease. This minireview article summarizes the inherited and acquired disorders with apparent GAA deficiency and discusses a possible relevance of GAA shortfall in clinical medicine.

Cyclophilin D knockout protects the mouse kidney against cyclosporin A-induced oxidative stress

Mitochondrial dysfunction and oxidative stress have been implicated in cyclosporin A (CsA)-induced nephrotoxicity. CsA interacts with cyclophilin D (CypD), an essential component of the mitochondrial permeability transition pore and regulator of cell death processes. Controversial reports have suggested that CypD deletion may or may not protect cells against oxidative stress-induced cell death. In the present study, we treated wild-type (WT) mice and mice lacking CypD [peptidylprolyl isomerase F knockout (Ppif-/-) mice] with CsA to test the role and contribution of CypD to the widely described CsA-induced renal toxicity and oxidative stress. Our results showed an increase in the levels of several known uremic toxins as well as the oxidative stress markers PGF2α and 8-isoprostane in CsA-treated WT animals but not in Ppif-/- animals. Similarly, a decline in S-adenosylmethionine and the resulting methylation potential indicative of DNA hypomethylation were observed only in CsA-treated WT mice. This confirms previous reports of the protective effects of CypD deletion on the mouse kidney mediated through a stronger resistance of these animals to oxidative stress and DNA methylation damage. However, a negative effect of CsA on the glycolysis and overall energy metabolism in Ppif-/- mice also indicated that additional, CypD-parallel pathways are involved in the toxic effects of CsA on the kidney. In summary, CsA-mediated induction of oxidative stress is associated with CypD, with CypD deletion providing a protective effect, whereas the reduction of energy production observed upon CsA exposure did not depend on the animals' CypD status.

Metabolic profiling of metformin treatment for low-level Pb-induced nephrotoxicity in rat urine

Chronic kidney disease is a worldwide problem, and Pb contamination is a potential risk factor. Since current biomarkers are not sensitive for the diagnosis of Pb-induced nephrotoxicity, novel biomarkers are needed. Metformin has both hypoglycaemic effects and reno-protection ability. However, its mechanism of action is unknown. We aimed to discover the early biomarkers for the diagnosis of low-level Pb-induced nephrotoxicity and understand the mechanism of reno-protection of metformin. Male Wistar rats were randomly divided into control, Pb, Pb + ML, Pb + MH and MH groups. Pb (250 ppm) was given daily via drinking water. Metformin (50 or 100 mg/kg/d) was orally administered. Urine was analysed by nuclear magnetic resonance (NMR)-based metabolomics coupled with multivariate statistical analysis, and potential biomarkers were subsequently quantified. The results showed that Pb-induced nephrotoxicity was closely correlated with the elevation of 5-aminolevulinic acid, D-lactate and guanidinoacetic acid in urine. After co-treatment with metformin, 5-aminolevulinic acid and D-lactate were decreased. This is the first demonstration that urinary 5-aminolevulinic acid, D-lactate and guanidinoacetic acid could be early biomarkers of low-level Pb-induced nephrotoxicity in rats. The reno-protection of metformin might be attributable to the reduction of D-lactate excretion.

Electrochemical recognition of taurine biomarker in unprocessed human plasma samples using silver nanoparticlebased nanocomposite: A new platform for early stage diagnosis of neurodegenerative diseases of the nervous system

The rapid and accurate determination of the level of taurine biomarker in various tissues and body fluids can be of great interest in the early diagnosis of several important pathologies and diseases. In the present study, an innovative electrochemical interface for quantitation of taurine based on ternary signal amplification strategy was fabricated. In this work, silver nanoparticles were electrodeposited onto green and biocompatible nanocomposite containing α-cyclodextrin as conductive matrix. Therefore, a double layer film based on α-cyclodextrin and silver nanoparticles was exploited to develop a highly sensitive electrochemical sensor for detection of taurine. Fully electrochemical methodology was used to prepare a transducer on a glassy carbon electrode which provided a high surface area towards sensitive detection of taurine biomarker. The surface morphology of electrode surface was characterized by high-resolution field emission scanning electron microscope (FE-SEM). The proposed sensing platform provides a simple tool for taurine detection. The calibration curve for taurine concentration was linear in 0.7 nM to 0.1 mM with low limit of quantification of 0.7 nM. The practical analytical utility of the modified electrode was illustrated by determination of taurine in unprocessed human plasma samples with recovery of 90.8% to 104%.

Total glycosides of Paeony shows Neuroprotective effects against Semen Strychni-induced neurotoxicity by recovering secretion of hormones and improving brain energy metabolism

In this study, we investigated the protective effect of total glycosides of paeony against Semen Strychni-induced neurotoxicity and discussed some probably mechanisms. Levels of estrone, estradiol, estriol and growth hormone in male rats' serum were determined by ELISA, levels of ATP and substances associated with energy metabolism in rats' brain were determined by HPLC and levels of progesterone was determined by a UPLC-MS/MS method. The results showed that neurotoxicity induced by Semen Strychni could cause a significant decrease (p < 0.05, compare to the blank group) in secretion of estrogens and GH and disorder brain energy metabolism at the same time. While, rats with total glycosides of paeony pre-protection (orally administrated with total glycosides of paeony for 15 days before administrating Semen Strychni extract) showed a much better condition in the secretion of hormones and brain energy metabolism, and showed no significant changes in most of those associated substances when comparing to the blank group. Our study indicated that total glycosides of paeony have neuroprotective effects on Semen Strychni-induced neurotoxicity. It could recover the disordered hormone secretion and improve the brain energy metabolism. Total glycosides of paeony is potential to be further used in clinic to protect against neurotoxicity induced by other reasons.

Investigation of the protective effect of Paeonia lactiflora on Semen Strychni-induced neurotoxicity based on monitoring nine potential neurotoxicity biomarkers in rat serum and brain tissue

Semen Strychni has been widely used as a traditional Chinese herb medicine, but its clinical use was limited for its potential neurotoxicity and nephrotoxicity. This study aimed to investigate S. Strychni-induced neurotoxicity and the neuro-protective effect of Paeonia lactiflora based on monitoring nine potential neurotoxicity biomarkers in rat serum and brain tissue. A sensitive liquid chromatography-tandem mass spectrometry method was developed and validated to monitor serotonin, tryptophan, dopamine, tyrosine and glutamate in serum and five brain regions (prefrontal cortex, hippocampus, striatum, cerebellum and hypothalamus). Analytes were separated on a CAPCELL CORE PC column (150 mm × 2 mm, 2.7 μm) with a gradient program of acetonitrile-water (0.2 % formic acid) and a total runtime of 7.5 min. In addition, enzyme-linked immunosorbent assay was conducted to determine four kinds of protein (tryptophan hydroxylase, tyrosine hydroxylase, endogenous brain-derived neurotrophic factor and nerve growth factor). Results demonstrated that the administration of S. Strychni could cause certain endogenous substances disorder. These analytes were found significantly changed (p < 0.05) in serum (except glutamate) and in certain tested brain regions in S. Strychni extract group. Pretreatment of P. lactiflora could significantly reverse the S. Strychni-induced neurotoxicity and normalize the levels of such endogenous substances. The study could be further used in predicting and monitoring neurotoxicity caused by other reasons, and it was expected to be useful for improving clinical use of S. Strychni through pretreatment with P. lactiflora.

An analytical strategy to investigate Semen Strychni nephrotoxicity based on simultaneous HILIC-ESI-MS/MS detection of Semen Strychni alkaloids, tyrosine and tyramine in HEK 293t cell lysates

A Previous metabolomics study has demonstrated that tyrosine metabolism might be disrupted by treating with Semen Strychni on the cell nephrotoxicity model. To investigate the relationship between Semen Strychni alkaloids (SAs) and endogenous tyrosine, tyramine under the nephrotoxicity condition, an HILIC-ESI-MS/MS based analytical strategy was applied in this study. Based on the established Semen Strychni nephrotoxicity cell model, strychnine and brucine were identified and screened as the main SAs by an HPLC-Q Exactive hybrid quadrupole Orbitrap mass system. Then, a sensitive HILIC-ESI-MS/MS method was developed to simultaneously monitor strychnine, brucine, tyrosine and tyramine in cell lysate. The analytes were separated by a Shiseido CAPCELL CORE PC (150mm×2.1mm, 2.7μm) HILIC column in an acetonitrile/0.1% formic acid gradient system. All the calibration curves were linear with regression coefficients above 0.9924. The absolute recoveries were more than 80.5% and the matrix effects were between 91.6%-107.0%. With the developed method, analytes were successfully determined in cell lysates. Decreased levels of tyrosine and tyramine were observed only in combination with increased levels of SAs, indicating that the disturbance of tyrosine metabolism might be induced by the accumulation of SAs in kidney cell after exposure of Semen Strychni. The HILIC-ESI-MS/MS based analytical strategy is a useful tool to reveal the relationships between the toxic herb components and the endogenous metabolite profiling in the toxicity investigation of herb medicines.

Detection of inflammatory biomarkers in saliva and urine: Potential in diagnosis, prevention, and treatment for chronic diseases

Inflammation is a part of the complex biological response of inflammatory cells to harmful stimuli, such as pathogens, irritants, or damaged cells. This inflammation has been linked to several chronic diseases including cancer, atherosclerosis, rheumatoid arthritis, and multiple sclerosis. Major biomarkers of inflammation include tumor necrosis factor, interleukins (IL)-1, IL-6, IL-8, chemokines, cyclooxygenase, 5-lipooxygenase, and C-reactive protein, all of which are regulated by the transcription factor nuclear factor-kappaB. Although examining inflammatory biomarkers in blood is a standard practice, its identification in saliva and/or urine is more convenient and non-invasive. In this review, we aim to (1) discuss the detection of these inflammatory biomarkers in urine and saliva; (2) advantages of using salivary and urinary inflammatory biomarkers over blood, while also weighing on the challenges and/or limitations of their use; (3) examine their role(s) in connection with diagnosis, prevention, treatment, and drug development for several chronic diseases with inflammatory consequences, including cancer; and (4) explore the use of innovative salivary and urine based biosensor strategies that may permit the testing of biomarkers quickly, reliably, and cost-effectively, in a decentralized setting.

Validation of a multi-analyte HPLC-DAD method for determination of uric acid, creatinine, homovanillic acid, niacinamide, hippuric acid, indole-3-acetic acid and 2-methylhippuric acid in human urine

During the last decades exposure sciences and epidemiological studies attracts more attention to unravel the mechanisms for the development of chronic diseases. According to this an existing HPLC-DAD method for determination of creatinine in urine samples was expended for seven analytes and validated. Creatinine, uric acid, homovanillic acid, niacinamide, hippuric acid, indole-3-acetic acid, and 2-methylhippuric acid were separated by gradient elution (formate buffer/methanol) using an Eclipse Plus C18 Rapid Resolution column (4.6mm×100mm). No interfering signals were detected in mobile phase. After injection of blank urine samples signals for the endogenous compounds but no interferences were detected. All analytes were linear in the selected calibration range and a non weighted calibration model was chosen. Bias, intra-day and inter-day precision for all analytes were below 20% for quality control (QC) low and below 10% for QC medium and high. The limits of quantification in mobile phase were in line with reported reference values but had to be adjusted in urine for homovanillic acid (45mg/L), niacinamide 58.5(mg/L), and indole-3-acetic acid (63mg/L). Comparison of creatinine data obtained by the existing method with those of the developed method showing differences from -120mg/L to +110mg/L with a mean of differences of 29.0mg/L for 50 authentic urine samples. Analyzing 50 authentic urine samples, uric acid, creatinine, hippuric acid, and 2-methylhippuric acid were detected in (nearly) all samples. However, homovanillic acid was detected in 40%, niacinamide in 4% and indole-3-acetic acid was never detected within the selected samples.

Identification of the toxic components in Semen Strychni and their metabolites in rat serum by high performance liquid chromatography coupled with a Q Exactive high-resolution benchtop quadrupole Orbitrap mass spectrometer

Scheme of the identification of components in vitro and in vivo.

Integrative investigation of Semen Strychni nephrotoxicity and the protective effect of Radix Glycyrrhizae by a UPLC-MS/MS method based cell metabolomics strategy in HEK 293t cell lysates

Scheme of the cell metabolomics strategy workflow.