Abnormalities of serum lipid metabolism in patients with acute paraquat poisoning caused by ferroptosis.

As the mechanism of paraquat (PQ) poisoning is still not fully elucidated, and no specific treatment has been developed in medical practice, the management of PQ poisoning continues to present a medical challenge. In this study, the objective was to investigate the early metabolic changes in serum metabolism and identify the key metabolic pathways involved in patients with PQ poisoning. Quantitative analysis was conducted to determine the relevant metabolites. Additionally, experiments were carried out in both plasma and cell to elucidate the mechanisms underlying metabolic disorder and cell death in PQ poisoning. The study found that polyunsaturated fatty acids (PUFAs) and their metabolites, such as arachidonic acid (AA) and hydroxy eicosatetraenoic acids (HETEs), were significantly increased by non-enzymatic oxidative reaction. Reactive oxygen species (ROS) production increased rapidly at 2 h after PQ poisoning, followed by an increase in PUFAs at 12 h, and intracellular glutathione, cysteine (Cys), and Fe2+ at 24 h. However, at 36 h later, intracellular glutathione and Cys decreased, HETEs increased, and the expression of SLC7A11 and glutathione peroxidase 4 (GPX4) decreased. Ultrastructural examination revealed the absence of mitochondrial cristae. Deferoxamine was found to alleviate lipid oxidation, and increase the viability of PQ toxic cells in the low dose. In conclusion, unsaturated fatty acids metabolism was the key metabolic pathways in PQ poisoning. PQ caused cell death through the induction of ferroptosis. Inhibition of ferroptosis could be a novel strategy for the treatment of PQ poisoning.

Plasma Concentration After the First Hemoperfusion has a High Predictive Value in Medium Level Acute Paraquat-Poisoned Patients.

BACKGROUND: Paraquat ( PQ) is very poisonous to humans and animals and there is no effective clinical antidote . The efficacy of hemoperfusion (HP) treatment for PQ poisoning remains controversial. To explore new ways to predict the prognosis of patients with acute PQ poisoning and assist in the development of better hemopurification treatment strategies. METHODS: The clinical data of patients who were intoxicated with PQ through contact were diagnosed with PQ poisoning by high-performance liquid chromatography. Samples were collected by the Emergency Intensive Care Unit of the First Affiliated Hospital of Wenzhou Medical University from January 2012 to November 2016. Based on the prognosis, the patients were grouped into survival and death groups. Comparisons of the differences in the clinical indexes were performed, including the initial concentration of PQ at admission, PQ concentration after first HP, the number of HP cartridges used for the first hemoperfusion, whether HP was combined with continuous renal replacement therapy, and the number of concurrent organ injuries between the 2 groups. In addition, data were analyzed using multivariate logistic regression models and receiver operating characteristic curves. Moreover, prognostic factors in patients with acute PQ poisoning were analyzed. RESULTS: Overall, 128 patients with acute PQ poisoning were enrolled in this study. The median plasma PQ concentrations of the patients at admission were 21 and 834 ng/mL (range: 50-1,099,118 ng/mL). The multiple logistic regression model revealed that the initial concentration of PQ and the PQ concentration after the first perfusion were independent risk factors for death in patients with acute PQ poisoning. The PQ concentration in the survival group after the first HP was <516 ng/mL and was mainly distributed at approximately 100 ng/mL. The percentage of patients whose concentration after the first HP was <516 ng/mL in the death group was only 19%. CONCLUSIONS: The initial plasma PQ concentration after admission and PQ concentration after the first HP are risk factors for death in patients with acute PQ poisoning. Moreover, PQ concentration after the first HP had a high predictive value for death. When the initial plasma PQ concentration after admission ranges from 50 ng/mL to 5000 ng/mL, the rapid reduction in plasma PQ concentration after HP treatment could improve the prognosis of patients with acute PQ poisoning.

Simultaneous determination of five essential amino acids in plasma of Hyperlipidemic subjects by UPLC-MS/MS.

BACKGROUND: Millions of adults have been reported with hyperlipemia in the world. It is still unclear whether the plasma level of essential amino acids (AAs) will be influenced by the hyperlipemia. This study was aimed to investigate the AAs levels and the underlying metabolic relationship in hyperlipidemic subjects. METHODS: An ultra-high performance liquid chromatography-tandem mass spectrometric (UPLC-MS/MS) method was developed for the determination of phenylalanine (Phe), valine (Val), histidine (His), tryptophan (Trp), and methionine (Met). Plasma samples (100 µL) were precipitated by acetonitrile (300 µL) and analyzed on a BEH C18 (2.1 mm × 100 mm, 1.7 µm) column at 40 °C by gradient elution. The mobile phase composed of 0.1% formic acid and acetonitrile was used with flow rate at 0.2-0.4 ml/0-3 min. Five AAs were determined at positive electrospray ionization (ESI+) at m/z 118.1/72.1 (Val), 150.12/104.02(Met), 156.06/110.05(His), 166.1/120.1(Phe), and 205.2/188.02 (Trp). A total of 75 healthy subjects and 83 hyperlipidemic subjects, who had blood routine test and plasma lipid test were determined by developed UPLC-MS/MS. RESULTS: It was shown that there was good linearity for Val, Met, His, Phe, and Trp within 1-100 µg/mL. The relative standard deviations of precision and accuracy were all within 15%. The level of Val, Phe, Trp, His, and Met were 35.34 ± 15.64, 22.72 ± 9.13, 17.23 ± 4.94, 16.78 ± 13.64, and 6.24 ± 1.97 µg/mL in healthy subjects, while they were 38.04 ± 16.70, 22.41 ± 8.45, 15.62 ± 5.77, 18.35 ± 14.49, and 6.21 ± 1.97 µg/mL in hyperlipidemic subjects respectively. The Spearman's correlations analysis showed that there were high correlations between Val, Phe, Trp, His, Met and triglyceride in healthy subjects. While, those correlations decreased in hyperlipemia cases. CONCLUSION: A convenient and sensitive method for simultaneous determination of Val, Phe, Trp, His, and Met in human plasma was developed. There was a high correlation between Val, Phe, Trp, His, Met and triglyceride. Hyperlipemia influences the metabolic balance of His, Phe, Trp, Met and Val.

Metabolomics Analysis in Acute Paraquat Poisoning Patients Based on UPLC-Q-TOF-MS and Machine Learning Approach.

Most paraquat (PQ) poisoned patients died from acute multiple organ failure (MOF) such as lung, kidney, and heart. However, the exact mechanism of intoxication is still unclear. In order to find out the initial toxic mechanism of PQ poisoning, a blood metabolomics study based on ultraperformance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) and efficient machine learning approach was performed on 23 PQ poisoned patients and 29 healthy subjects. The initial PQ plasma concentrations of PQ poisoned patients were >1000 ng/mL, and the blood samples were collected at before first hemoperfusion (HP), after first HP, and after last HP. The results showed that PQ poisoned patients all differed from healthy subjects, whatever they were before or after first HP or after last HP. The efficient machine learning approaches selected key metabolites from three UPLC/Q-TOF-MS data sets which had the highest classification performance in terms of classification accuracy, Matthews Correlation Coefficients, sensitivity, and specificity, respectively. The mass identification revealed that the most important metabolite was adenosine, which sustained in low level, regardless of whether PQ poisoned patients received HP treatment. In conclusion, decreased adenosine was the most important metabolite in PQ poisoned patients. The metabolic disturbance caused by PQ poisoning cannot be improved by HP treatment even the PQ was cleared from the blood.

Diagnostic value of complete blood count in paraquat and organophosphorus poisoning patients.

Complete blood count (CBC) is one of the most extensively used tests in clinical practice. In order to determine the diagnostic value of the CBC in paraquat (PQ) and organophosphorus (OPPs) poisoning, the CBC indices of PQ- and OPPs-poisoned patients were investigated in this study. A total of 96 PQ poisoning patients, 90 OPPs poisoning patients, and 188 healthy subjects were included in this study. The PQ- and OPPs-poisoned patients were divided into different groups according to their clinical symptoms. All CBC indices were analyzed by Fisher discriminant, partial least-squares discriminant analysis (PLS-DA), variance analysis, and receiver operating characteristic (ROC). The discriminant results showed that 87.7% of original grouped cases correctly classified between PQ-poisoned patients, OPPs-poisoned patients, and healthy subjects. The PLS-DA results showed that the important variable order was different in PQ- and OPPs-poisoned patients. Both white blood cell (WBC) and neutrophil (NE) counts were the most important indexes in PQ- and OPPs-poisoned patients. In OPPs poisoning patients, WBC and NE showed statistical differences between the severe poisoning group and the moderate poisoning group. Their areas under the ROC curve (AUC) were 0.673 (WBC) and 0.669 (NE), which were higher than cholinesterase (CHE; AUC 0.326). In conclusion, the CBC indices had a diagnostic value in PQ and OPPs poisoning; WBC and NE were the first responses and had clinical significance in PQ and OPPs poisoning; moreover, they are better than CHE in diagnosing OPPs poisoning.

Early Metabolome Profiling and Prognostic Value in Paraquat-Poisoned Patients: Based on Ultraperformance Liquid Chromatography Coupled To Quadrupole Time-of-Flight Mass Spectrometry.

Paraquat (PQ) has caused countless deaths throughout the world. There remains no effective treatment for PQ poisoning. Here we study the blood metabolome of PQ-poisoned patients using ultraperformance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF MS). Patients were divided into groups according to blood PQ concentration. Healthy subjects served as controls. Metabolic features were statistically analyzed using multivariate pattern-recognition techniques to identify the most important metabolites. Selected metabolites were further compared with a series of clinical indexes to assess the prognostic value. PQ-poisoned patients showed substantial differences compared with healthy subjects. Based on variable of importance in the project (VIP) values and statistical analysis, 17 metabolites were selected and identified. These metabolites well-classified low PQ-poisoned patients, high PQ-poisoned patients, and healthy subjects, which was better than that of a complete blood count (CBC). Among the 17 metabolites, 20:3/18:1-PC (PC), LPA (0:0/16:0) (LPA), 19-oxo-deoxycorticosterone (19-oxo-DOC), and eicosapentaenoic acid (EPA) had prognostic value. In particular, EPA was the most sensitive one. Besides, the levels of EPA was correlated with LPA and 19-oxo-DOC. If EPA was excessively consumed, then prognosis was poor. In conclusion, the serum metabolome is substantially perturbed by PQ poisoning. EPA is the most important biomarker in early PQ poisoning.

Fisher Discrimination of Metabolic Changes in Rats Treated with Aspirin and Ibuprofen.

BACKGROUND: Aspirin and ibuprofen are the most frequently prescribed non-steroidal anti-inflammatory drugs in the world. However, both are associated with a variety of toxicities. We applied serum metabonomics and Fisher discrimination for the early diagnosis of its toxic reaction in order to help diagnose these toxicities. METHODS: A total of 45 rats were randomly divided into Control group, Aspirin group, and Ibuprofen groups. The experiment groups were given intragastric aspirin (15 mg/kg) or ibuprofen (15 mg/kg) for 3 weeks. Liver function tests were performed and blood metabonomics were analyzed by gas chromatography-mass spectrometry. RESULTS: The most important compounds altered were trihydroxybutyric acid and l-alanine in the aspirin group, and acetoacetic acid, l-alanine, and trihydroxybutyric acid in the ibuprofen group. With respect to metabolic profiles, all 3 groups were completely distinct from one another. Fisher discrimination showed that 91.1% of the original grouped cases were correctly classified by the third week. However, only 55.6% of liver function tests were able to classify grouped cases correctly. CONCLUSION: Trihydroxybutyric acid, l-alanine, and acetoacetic acid were the most significant indicators of altered serum metabolites following intragastric administration of aspirin and ibuprofen in rates. These metabolomic data may be used for classification of aspirin and ibuprofen toxicity.

Serum metabolic changes in rats after intragastric administration of dextromethorphan.

Dextromethorphan is recognized as a substance of abuse around the world. An estimated 3.1 million people between the ages of 12 and 25 years (5.3%) misused over-the-counter cough and cold medications in 2006. In this study, we developed a serum metabolomic method by gas chromatography-mass spectrometry (GC-MS) to evaluate the effect of abuse of dextromethorphan on rats. The dextromethorphan-treated rats were given 12, 24 and 48 mg/kg (low, medium, high) of dextromethorphan by intragastric administration each day for 3 days. Partial least squares-discriminate analysis revealed that intragastric administration of dextromethorphan induced metabolic perturbations. Compared with the control (healthy) group, the levels of propanoic acid, urea, heptafluorobutanoic acid, 2-hexyldecanoic acid and butanedioic acid of the low group decreased; levels of propanoic acid and heptafluorobutanoic acid of the medium group decreased, while that of benzoic acid increased; and levels of 2-hexyldecanoic acid, glycerol and butanedioic acid of the high group increased. These biomarkers are involved in the citric acid cycle, urea cycle, glycerolipid metabolism and tricarboxylic acid cycle. The results indicate that the metabolomic method by GC-MS may be useful to elucidate abuse of dextromethorphan. According to the pathological changes in the liver at different dosages, dextromethorphan is not hepatotoxic after intragastric administration of 12, 24 and 48 mg/kg for 3 days.

Tissue metabolic changes for effects of pirfenidone in rats of acute paraquat poisoning by GC-MS.

We developed a metabolomic method to evaluate the effect of pirfenidone on rats with acute paraquat (PQ) poisoning, through the analysis of various tissues (lung, liver, kidney, and heart), by gas chromatography-mass spectrometry (GC-MS). Thirty-eight rats were randomly divided into a control group, an acute PQ (20 mg kg-1) poisoning group, a pirfenidone (20 mg kg-1) treatment group, and a pirfenidone (40 mg kg-1) treatment group. Partial least squares-discriminate analysis (PLS-DA) revealed metabolic alterations in rat tissue samples from the two pirfenidone treatment groups after acute PQ poisoning. The PLS-DA 3D score chart showed that the rats in the acute PQ poisoning group were clearly distinguished from the rats in the control group. Also, the two pirfenidone treatment groups were distinguished from the acute PQ poisoning group and control group. Additionally, the pirfenidone (40 mg kg-1) treatment group was separated farther than the pirfenidone (20 mg kg-1) treatment group from the acute PQ poisoning group. Evaluation of the pathological changes in the rat tissues revealed that treatment with pirfenidone appeared to decrease pulmonary fibrosis in the acute PQ poisoning rats. The results indicate that pirfenidone induced beneficial metabolic alterations in the tissues of rats with acute PQ poisoning. Rats with acute PQ poisoning exhibited a certain reduction in biochemical indicators after treatment with pirfenidone, indicating that pirfenidone could protect liver and kidney function. Accordingly, the developed metabolomic approach proved to be useful to elucidate the effect of pirfenidone in rats of acute PQ poisoning.

Correlations of Cerebrospinal Fluid/Plasma Fibroblast Growth Factor 21 Ratio with Metabolic Parameters in Chinese Individuals of Normal Weight.

BACKGROUND: Fibroblast growth factor 21 (FGF21) is an important metabolic regulator that has multiple beneficial effects on glucose homeostasis and lipid metabolism. Although circulating levels of FGF21 are mainly derived from liver, FGF21 is also found in other tissues and fluids including the cerebrospinal fluid (CSF). The aim of the present study was to investigate the relationships of CSF and/or plasma FGF21 levels with metabolic parameters in a normal-weight Chinese population. METHODS: Forty-five subjects (22 males and 23 females) were recruited from a patient population undergoing surgery for lower extremity injuries due to ligament damage or bone fractures below the knee in the Beijing Jishuitan Hospital. The levels of FGF21 in CSF and plasma were determined by radioimmunoassay and enzyme-linked immunosorbent assay, respectively. RESULTS: No significant differences were detected in the levels of FGF21 in CSF and plasma between males (CSF: 158.01 ± 12.10 pg/mL; plasma: 206.19 ± 7.22 pg/mL) and females (CSF: 159.27 ± 17.85 pg/mL; plasma: 203.10 ± 7.53 pg/mL). The level of FGF21 in CSF was about 75% of that in plasma. The FGF21 level in CSF was positively correlated with triglyceride level, whereas plasma FGF21 level was negatively correlated with alanine aminotransferase in women but not in men. The CSF/plasma FGF21 ratio was positively correlated with CSF FGF21 in both genders and with peripheral glucose, triglyceride, and gamma-glutamyl transferase levels in female Chinese patients. CONCLUSIONS: These results have important implications regarding the potential central actions of FGF21.

Brain metabolomics in rats after administration of ketamine.

In this study, we developed a brain metabolomic method, based on gas chromatography-mass spectrometry (GC/MS), to evaluate the effect of ketamine on rats. Pattern recognition analysis, including both principal component analysis and partial least squares-discriminate analysis revealed that ketamine induced metabolic perturbations. Compared with the control group, the levels of glycerol, uridine, cholesterol in rat brain of the ketamine group (50 mg/kg, 14 days) decreased, while the urea levels increased. Our results indicate that metabolomic methods based on GC/MS may be useful to elucidate ketamine abuse through the exploration of biomarkers.

Metabolic changes in rat urine after acute paraquat poisoning and discriminated by support vector machine.

Paraquat is quick-acting and non-selective, killing green plant tissue on contact; it is also toxic to human beings and animals. In this study, we developed a urine metabonomic method by gas chromatography-mass spectrometry to evaluate the effect of acute paraquat poisoning on rats. Pattern recognition analysis, including both partial least squares discriminate analysis and principal component analysis revealed that acute paraquat poisoning induced metabolic perturbations. Compared with the control group, the levels of benzeneacetic acid and hexadecanoic acid of the acute paraquat poisoning group (intragastric administration 36 mg/kg) increased, while the levels of butanedioic acid, pentanedioic acid, altronic acid decreased. Based on these urinary metabolomics data, support vector machine was applied to discriminate the metabolomic change of paraquat groups from the control group, which achieved 100% classification accuracy. In conclusion, metabonomic method combined with support vector machine can be used as a useful diagnostic tool in paraquat-poisoned rats.

Metabolic changes in paraquat poisoned patients and support vector machine model of discrimination.

Numerous people die of paraquat (PQ) poisoning every year in the world. Although several studies regarding paraquat (PQ) poisoning have been conducted, the metabolic changes in plasma remain unknown. In this study, the metabolomics of 15 PQ poisoned patients with plasma PQ concentrations in excess of 0.1 µg/mL and 16 healthy volunteers were investigated. The plasma samples were evaluated through the use of gas chromatography-mass spectrometry (GC/MS) and analyzed by partial least-squares discriminant analysis (PLS-DA). Based on the metabolomics data, a support vector machine (SVM) discrimination model was developed. The results showed the plasma levels of urea, glucose oxime and L-phenylalanine decreased and cholesterol increased in PQ poisoned patients in comparison to healthy volunteers. The SVM discrimination model was developed, and performed with a high degree of accuracy, to distinguish PQ poisoned patients from healthy volunteers. In conclusion, metabolic pathways including the urea cycle, and amino acid, glucose, and cholesterol metabolism were impaired after PQ poisoning. An SVM discrimination model, based on metabolomics data, was established and may become a new powerful tool for the diagnosis of PQ poisoning.

Serum Metabolomics in Rats after Acute Paraquat Poisoning.

Paraquat is one of the most widely used herbicides in the world and is highly toxic to humans and animals. In this study, we developed a serum metabolomic method based on GC/MS to evaluate the effects of acute paraquat poisoning on rats. Pattern recognition analysis, including both principal component analysis and partial least squares-discriminate analysis revealed that acute paraquat poisoning induced metabolic perturbations. Compared with the control group, the level of octadecanoic acid, L-serine, L-threonine, L-valine, and glycerol in the acute paraquat poisoning group (36 mg/kg) increased, while the levels of hexadecanoic acid, D-galactose, and decanoic acid decreased. These findings provide an overview of systematic responses to paraquat exposure and metabolomic insight into the toxicological mechanism of paraquat. Our results indicate that metabolomic methods based on GC/MS may be useful to elucidate the mechanism of acute paraquat poisoning through the exploration of biomarkers.

Effect of Dimethoate on the Activity of Hepatic CYP450 Based on Pharmacokinetics of Probe Drugs.

BACKGROUND: Dimethoate (DM), one of the most widely used systemic organophosphate insecticide, has been reported to exert toxic effects after long-time subchronic exposure. This study aims at investigating the toxic effect of DM on liver after repeated administration of low doses of DM in rats. METHODS: Twenty Sprague-Dawley rats were randomly divided into the control group (n = 10) and the DM group (n = 10). After 2 weeks' exposure to DM at low dosage (5 mg/kg), biochemical parameters of hepatic functions were measured, histology and CYP450 expressed in liver was detected. The activities of CYP1A2, CYP2C11, CYP2D1, and CYP3A2 were evaluated by the Cocktail method. RESULTS: The level of AChE (acetylcholinesterase) was significantly decreased, hepatic functions were damaged and the mRNA level of CYP2D1 was significantly increased in the DM group (p < 0.05). The pharmacokinetics of probe drug revealed AUC(0-t), AUC(0-∞), t1/2 and Cmax of metoprolol was shorten in the DM group (p < 0.05). However, there were no statistical differences in MRT, t1/2, CL and Tmax for phenacetin, tolbutamide and midazolam. CONCLUSIONS: A low dosage of DM could induce the activity of CYP2D1 in liver and increase the metabolism of metoprolol when exposed for 2 weeks.

Liquid chromatography mass spectrometry simultaneous determination of vindoline and catharanthine in rat plasma and its application to a pharmacokinetic study.

Vinblastine and vincristine, both of which are bisindole alkaloids derived from vindoline and catharanthine, have been used for cancer chemotherapy; their monomeric precursor molecules are vindoline and catharanthine. A simple and selective liquid chromatography mass spectrometry method for simultaneous determination of vindoline and catharanthine in rat plasma was developed. Chromatographic separation was achieved on a C18 (2.1 × 50 mm, 3.5 µm) column with acetonitrile-0.1% formic acid in water as mobile phase with gradient elution. The flow rate was set at 0.4 mL/min. An electrospray ionization source was applied and operated in positive ion mode; selective ion monitoring mode was used for quantification. Mean recoveries were in the range of 87.3-92.6% for vindoline in rat plasma and 88.5-96.5% for catharanthine. Matrix effects for vindoline and catharanthine were measured to be between 95.3 and 104.7%. Coefficients of variation of intra-day and inter-day precision were both <15%. The accuracy of the method ranged from 93.8 to 108.1%. The method was successfully applied in a pharmacokinetic study of vindoline and catharanthine in rats. The bioavailability of vindoline and catharanthine were 5.4 and 4.7%, respectively.

Pharmacokinetic interaction of entinostat and lapatinib following single and co-oral administration in rats.

1. Entinostat, also known as SNDX-275 or MS-275, is a novel, potent, orally bioavailable, class I selective histone deacetylase inhibitor. Pre-clinical data has show that MS-275 can enhance the activity of lapatinib in HER(2+) metastatic inflammatory and non-inflammatory breast cancer. This study examined whether oral administration of MS-275 to the rats with lapatinib led to any pharmacokinetic interactions. 2. To evaluate pharmacokinetic interaction of MS-275 and lapatinib in rat, a sensitive and simple LC-MS method was developed to simultaneously determine MS-275 and lapatinib in rat plasma with carbamazepine as internal standard (IS). Eighteen rats were divided randomly into three groups, lapatinib group (lapatinib 15 mg/kg, n = 8), MS-275 group (MS-275 15 mg/kg, n = 8) and co-administration group (MS-275 15 mg/kg and lapatinib 15 mg/kg, n = 8). 3. There was no statistical pharmacokinetics difference for MS-275 in MS-275 group and co-administration group; the lapatinib could not influence the pharmacokinetic profile of MS-275 in rats. However, there is a statistical pharmacokinetics difference between lapatinib in the lapatinib group and co-administration group, when co-oral administration MS-275 with lapatinib, AUC increased from 2375.5 to 9900.3 ng/mL h (p < 0.05), Cmax increased from 538.0 to 2578.2 ng/mL (p < 0.01), CL decreased from 6.2 to 1.7 L/h/kg (p < 0.01). 4. These data indicate MS-275 could obviously influence the pharmacokinetic profile of lapatinib in rats, which might cause drug-drug interactions in humans when using lapatinib with MS-275. Further investigations should be carried out to elucidate the synergistic mechanisms between the two drugs.

Synaptotagmin-1 antagonizes paraquat intracellular accumulation and nephrocyte toxicity by up-regulating SERBP1/GLUT2 expression.

Acute kidney injury (AKI) is common and an independent risk factor for mortality in patients with paraquat (PQ) poisoning. Currently, no specific antidote is available. Synaptotagmin-1 (SYT1) has been identified as a key protein that facilitates PQ efflux in PQ-resistant A549 cells, thereby preventing PQ-induced lung injury. However, the protective effect of STY1 on PQ-induced AKI remains to be elucidated. This study exposed human kidney 2 (HK-2) cells overexpressing SYT1 to PQ. These cells exhibited significantly lower levels of growth inhibition, reactive oxygen species production, early apoptosis, and PQ accumulation compared to the parent HK-2 cells. Transcriptomic screening and Western blot analysis revealed that SYT1 overexpression significantly promoted the expression of glucose transporter 2 (GLUT2). Inhibition of GLUT2 completely abolished the protective effects of SYT1 overexpression in HK-2 cells and restored intracellular PQ concentrations. Further immunoprecipitation-shotgun and RNA interference experiments revealed that SYT1 binds to and stabilizes the protein SERPINE1 mRNA-binding protein 1 (SERBP1), enhancing the stability of GLUT2 mRNA and its protein levels. In summary, SYT1 antagonizes PQ intracellular accumulation and prevents nephrocyte toxicity by up-regulating SERBP1/GLUT2 expression. This study identifies a potential target for the treatment of PQ-induced AKI.

Assessment of effects of chronic hydrogen sulfide poisoning on cytochrome P450 isoforms activity of rats by cocktail approach.

Hydrogen sulfide (H2S) is one of the neurotoxic gases with suffocating and irritating. Its main target organs of toxic effects are the central nervous system and respiratory system. Cocktail method was used to evaluate the influence of chronic hydrogen sulfide poisoning on the activities of cytochrome P450 (CYP450) isoforms CYP1A2, CYP2C9, CYP2B6 and CYP2D6, which were reflected by the changes of pharmacokinetic parameters of 4 specific probe drugs phenacetin, tolbutamide bupropion and metroprolol, respectively. The experimental rats were randomly divided into two groups, control group and chronic hydrogen sulfide poisoning group. The chronic hydrogen sulfide poisoning group rats were inhaled 20 ppm for 1 h twice a day for 40 d. The mixture of 4 probes was given to rats through sublingual veins and the blood samples were obtained at a series of time-points through the caudal vein. The concentrations of probe drugs in rat plasma were measured by liquid chromatography-mass spectrometry (LC-MS). In the experiment for chronic hydrogen sulfide poisoning and control group, there was a statistically significant difference in the area under the plasma concentration-time curve from zero to infinity (AUC(0-∞)), plasma clearance (CL) and maximum plasma concentration (C(max)) for phenacetin and bupropion, while there was no statistical pharmacokinetics difference for tolbutamide and metoprolol. Chronic hydrogen sulfide poisoning could induce the activity of CYP1A2 and CYP2B6 of rats.

Effects of repeated allopurinol administration on rat cytochrome P450 activity.

Allopurinol is a popular and widely-prescribed anti-hyperuricemic agent that has been implicated in drug interactions with substrates of several cytochrome P450 (CYP) enzymes. The effect of repeated allopurinol administration (20 mg/kg, once daily for 14 days) on metabolic activity of CYP was assessed in rats. This was a randomized, double-blind, two-way crossover study with a 4-week washout period between phases. The substrates used in this study were phenacetin (CYP1A2), tolbutamide (CYP2C9), omeprazole (CYP2C19) and dextromethorphan (CYP2D6). Validated HPLC-MS/MS was used to quantify all compounds. Our study showed that allopurinol administration inhibited CYP1A2 activity, causing a significant increase in AUC (0-infinity) (P < 0.01) and t1/2 (P < 0.05) of phenacetin, and a distinct decline in CL (P < 0.01). However, there were no significant differences of another three probe drugs in plasma concentrations and the corresponding pharmacokinetic parameters between the allopurinol-treated and normal saline-treated rats. The findings in this study suggested that allopurinol could inhibit CYP1A2 but did not influence CYP2C9, CYP2C19 and CYP2D6 enzymes.