Acute diquat intoxication. Interest of its repeated determination in urine and the evaluation of renal proximal tubule integrity

[A Preliminary Study on the Plasma Metabolomic Profiles of Patients Suffering From Acute Diquat Poisoning]

Objective

To analyze the plasma metabolomic features of patients suffering from acute diquat (DQ) poisoning and to explore the molecular mechanism and potential biomarkers of DQ poisoning.

Methods

A total of 7 patients suffering from acute DQ poisoning were enrolled in the DQ poisoning group. The poisoning of these patients occurred within a 12-h window at the time of enrollment. Meanwhile, 7 healthy immediate family members of the patients were enrolled as the normal controls. Liquid chromatography-mass spectrometry (LC-MS) was used to perform non-targeted metabolomic profiling of the plasma samples and to screen and identify differential metabolites and metabolic pathways.

Results

A total of 104 metabolites were screened and identified (P<0.05 and the variable importance in the projection [VIP]>1). Compared with those of the control group, 61 metabolites, such as sorbitol and galactitol, were up-regulated, and 43 metabolites, such as myo-inositol and gamma-glutamylcysteine, were down-regulated in the DQ poisoning group. Pathway enrichment analysis revealed changes in 11 metabolic pathways, including those for galactose metabolism and linoleic acid metabolism (P<0.05).

Conclusion

Metabolomics analysis of plasma samples from DQ poisoning patients shows that DQ mainly interferes with the metabolism of energy, amino acids, and lipids, thus causing metabolic disorders. Some potential biomarkers closely associated with oxidative stress and organ damage of the liver, kidney, and nervous system have been identified.

Protective activities of ellagic acid and urolithins against kidney toxicity of environmental pollutants: A review

Oxidative stress and inflammation are two possible mechanisms related to nephrotoxicity caused by environmental pollutants. Ellagic acid, a powerful antioxidant phytochemical, may have great relevance in mitigating pollutant-induced nephrotoxicity and preventing the progression of kidney disease. This review discusses the latest findings on the protective effects of ellagic acid, its metabolic derivatives, the urolithins, against kidney toxicity caused by heavy metals, pesticides, mycotoxins, and organic air pollutants. We describe the chelating, antioxidant, anti-inflammatory, antifibrotic, antiautophagic, and antiapoptotic properties of ellagic acid to attenuate nephrotoxicity. Furthermore, we present the molecular targets and signaling pathways that are regulated by these antioxidants, and suggest some others that should be explored. Nevertheless, the number of reports is still limited to establish the efficacy of ellagic acid against kidney damage induced by environmental pollutants. Therefore, additional preclinical studies on this topic are required, as well as the development of well-designed clinical trials.

Acute diquat poisoning causes rhabdomyolysis

We studied the case of a 36-year-old female patient who self-administered about 30 ml of diquat solution (200 g/L) during a suicide attempt. She developed nausea, vomiting, dizziness, and weakness in her limbs and was admitted to the emergency department of our hospital 4 h later. The patient developed progressive swelling and pain in both calves 12 h after admission. Based on symptoms, lower limb color Doppler ultrasound, and elevated levels of myoglobin and creatine kinase, the patient was diagnosed with rhabdomyolysis caused by diquat poisoning. The patient recovered and was discharged after treatment with hemoperfusion, continuous venovenous hemodialysis, acid suppression, liver protection, low-dose glucocorticoids, etc. Rhabdomyolysis caused by diquat poisoning has not been previously reported. We attempted to analyze the mechanism of this symptom through a literature review. We recommend the routine monitoring of creatine phosphokinase (CK) and myoglobin (MYO) in patients with diquat poisoning to avoid missed diagnosis. Further, the mechanism of this poisoning symptom was discussed through the literature review.

Human and experimental toxicology of diquat poisoning: Toxicokinetics, mechanisms of toxicity, clinical features, and treatment

Diquat (1,1'-ethylene-2,2'-bipyridinium ion; DQ) is a nonselective quick-acting herbicide, which is used as contact and preharvest desiccant to control terrestrial and aquatic vegetation. Several cases of human poisoning were reported worldwide mainly due to intentional ingestion of the liquid formulations. Its toxic potential results from its ability to produce reactive oxygen and nitrogen species through redox cycling processes that can lead to oxidative stress and potentially cell death. Kidney is the main target organ due to DQ toxicokinetics and redox cycling. There is no antidote against DQ intoxications, and the efficacy of treatments currently applied is still unsatisfactory. The aim of this work was to review the most relevant human and experimental findings related to DQ, characterizing its chemistry, activity as herbicide, mechanisms of toxicity, consequences of poisoning, and potential therapeutic approaches taking into account previous experience in developing antidotes for paraquat, a more toxic bipyridinium herbicide.

Method for measurement of the quaternary amine compounds paraquat and diquat in human urine using high-performance liquid chromatography-tandem mass spectrometry

We have developed a highly selective and sensitive analytical method to quantify paraquat and diquat by use of high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The sample preparation includes solid phase extraction that uses weak cation exchange cartridges. These highly charged dual quaternary amines were not retained by standard reversed phase columns, but they could be adequately separated through HPLC with a HILIC column. The detection was carried out with a triple quadrupole mass spectrometer with an electrospray ionization probe in positive ion mode in multiple reaction monitoring. Repeated analysis in human urine samples spiked with low (5 ng/ml), medium (15 ng/ml), and high (30 ng/ml) concentrations of the analytes yielded relative standard deviations of less than 9%. The extraction efficiencies ranged from 77.7% to 94.2%. The limits of detection were in the range of 1 ng/ml.

Fatal diquat intoxication

Background. Since the introduction of diquat in agriculture practice in 1960's, about 40 cases of poisoning have been described in detail in medical literature. Case report. We presented two cases. A case one, a 35-year-old, previously healthy, woman ingested 14% diquat solution. The poisoning had fulminant course, consisted of severe stomachache, vomiting, cardiocirculatory shock, respiratory failure and cardiac arrest 20 hours post-ingestion. Autopsy revealed myocardial infarction, bronchopneumonia and incipient renal damage. A case two, a 64-year-old man developed severe gastroenteritis, corrosive lesions of mucosal surfaces, acute renal injury, arrhythmias, brain stem infarction and bronchopneumonia. The diagnosis of diquat poisoning was made retrospectively upon the clinical picture and identification of pesticides he had been exposed to. The patient died 18 days post-exposure. The most prominent findings on autopsy were pontine hemorrhage and infarction, bronchopneumonia, left ventricle papillary muscle infarction and renal tubular damage. Conclusion. Cardiocirculatory disturbances led to fatal complications, the heart and brain infarction. We pointed out the heart as one of the most severely affected organs in diquat poisoning.

Oral mucosal response to exposure to diquat: a rare occupational injury

Diquat is a quaternary ammonium herbicide closely related to paraquat, and is used commonly by commercial and domestic gardeners. The systemic toxicity of this group of compounds is well-known, but isolated human oral mucosal responses to topical exposure are not well-reported. We present details of an accidental mucosal exposure to diquat during manufacture and the resultant injury, and give guidance for appropriate management of such an exposure.

Determination of paraquat and diquat in human body fluids by high-performance liquid chromatography/tandem mass spectrometry

Paraquat (PQ) and diquat (DQ) in human whole blood and urine were analyzed by high-performance liquid chromatography/tandem mass spectrometry (HPLC/MS/MS) with positive ion electrospray ionization (ESI). The compounds were extracted with Sep-Pak C18 cartridges from whole blood and urine samples containing ethyl paraquat as an internal standard. The separation of PQ and DQ was carried out using ion-pair chromatography with heptafluorobutyric acid in 20 mM ammonium acetate and acetonitrile gradient elution for successful coupling with MS. Both compounds formed base peaks due to [M-H]+ ions by HPLC/ESI-MS and the product ions produced from each [M-H]+ ion by HPLC/MS/MS. Selective reaction monitoring (SRM) showed much higher sensitivity for both body fluids. Therefore, a detailed procedure for the detection of compounds by SRM with HPLC/MS/MS was established and carefully validated. The recoveries of PQ and DQ were 80.8-95.4% for whole blood and 84.2-96.7% for urine. The calibration curves for PQ and DQ showed excellent linearity in the range of 25-400 ng ml(-1) of whole blood and urine. The detection limits were 10 ng ml(-1) for PQ and 5 ng ml(-1) for DQ in both body fluids. The intra- and inter-day precision for both compounds in whole blood and urine samples were not greater than 13.0%. The data obtained from the determination of PQ and DQ in rat blood after oral administration of the compounds are also presented.

A case of fatal diquat poisoning: toxicokinetic data and autopsy findings

CASE REPORT

A 37-year-old man ingested in a suicide attempt 300 mL of a diquat solution (equivalent to 60 g diquat ion). The initial diquat serum concentration was 64 microg/mL 4 hours after poisoning. The clinical course was characterized by a progressive anuria and by neurological disorders (coma and seizures). The patient died 26 hours after poisoning from refractory cardiocirculatory collapse. Extracorporeal techniques removed 1.09 g of diquat which could be considered as significant in regard to the total amount that was likely absorbed, but they did not influence the clinical outcome. There was marked renal tubular damage at autopsy and the highest diquat tissue concentration was found in the kidneys.

Biological Monitoring of Pesticide Exposure: a review. Introduction

Pesticides are used worldwide in agriculture, industry, public health and for domestic applications: as a consequence, a great part of the population may be exposed to these compounds. In spite of this extensive use, knowledge on the health risks associated with prolonged exposure is rather poor, and major uncertainties still exist. Epidemiological observations in man have so far produced little conclusive information, mainly because of weaknesses in exposure assessment. Therefore, information on the type and levels of exposure is fundamental in order to better understand and characterize risk to human health. Exposure assessment can be carried out via measurement of environmental concentrations, as well as via determination of the chemical or its metabolites in body tissues (biological monitoring). Besides indices of internal dose, biological monitoring also includes measurements of early effects attributable to interaction between the chemical agent and the human body. Biological monitoring has the advantage, over environmental monitoring, of determining the dose actually absorbed via any possible route: differences in absorption can be taken into account. whether they are due to biological variability or to use of protective equipment. When, in some cases, a combination of occupational and non-occupational exposure occurs, this also can be taken into consideration by biological monitoring. Few reference documents have been published on biological monitoring of pesticides. For this reason, the Office of Occupational Health of the World Health Organization gave ICPS a mandate to prepare a monograph specifically addressed to reviewing methods for biological monitoring of pesticide exposure. This review is based on more than 300 studies published over the period 1980-1999. For the most representative chemical classes, the available biological exposure indices are reported. Both indices of internal dose and. when available, of early effects are discussed. The reported tests were used to monitor exposure of pesticide applicators in agriculture and public health, manufacturing and formulating workers. subjects poisoned after accidental exposure or attempted suicide, volunteers involved in pharmacokinetic studies, as well as sub-groups of the general population exposed to environmentally persistent pesticides. Single chapters deal with organophosphorus insecticides, carbamate pesticides, dithiocarbamates, phenoxyacids, quaternary ammonium compounds. coumarin rodenticides, synthetic pyrethroids, organochlorine pesticides, chlorotriazines, and pentachlorophenol.

Vaginally applied diquat intoxication

CASE REPORT

We report the case of a woman who introduced 20 mL of diquat concentrate intravaginally. Abdominal pain, vomiting, diarrhea, burning chest pains, and somnolence appeared within the first 24 hours. The vulva and vagina were corrosively inflamed. Acute renal failure appeared on the third day and was treated by 6 hemodialyses over 6 days. The patient was dysarthric with spastic tetraparesis for 3 months. The electroencephalogram, diffusely slow on day 3, was normal on day 28. The electromyoneurogram was normal at all times. Biopsy of a peripheral nerve performed on day 57 following intoxication showed no myelin or axonal alterations.

Mechanisms of toxicity, clinical features, and management of diquat poisoning: a review

USES: Diquat (1,1'-ethylene-2,2'-bipyridilium) is a nonselective bipyridyl herbicide, related structurally to paraquat, which is used both as a contact herbicide and a preharvest desiccant. In comparison to paraquat, diquat is used much less widely in agriculture.

MECHANISMS OF TOXICITY

Diquat is a potent redox cycler and is readily converted to a free radical which, in reaction with molecular oxygen, generates superoxide anions and subsequently other redox products. These products can induce lipid peroxidation in cell membranes, and potentially cause cell death.

FEATURES

Over the period 1968-1999, only 30 cases of diquat poisoning were reported in detail in the literature, of which 13 (43%) were fatal. Local and systemic effects have been reported following diquat exposure, with systemic features being invariably associated with ingestion. In severe and usually fatal cases, gastrointestinal mucosal ulceration, paralytic ileus, hypovolemic shock, acute renal failure, and coma have been reported.

MANAGEMENT

After rapid confirmation of the diagnosis using a qualitative urine test, gut decontamination may be considered in patients who present within 1 hour of a life-threatening ingestion (>6 g). Supportive measures including fluid and electrolyte replacement should then be employed. Although hemofiltration and hemodialysis are of proven value if renal failure supervenes, there is no clinical evidence that hemodialysis or hemoperfusion removes toxicologically significant amounts of diquat, thereby reducing the risk of organ failure and preventing a fatal outcome in severe cases.

Renal failure and corrosive airway and gastrointestinal injury after ingestion of diluted diquat solution

A 66-year-old man ingested 200 mL of Dexol Industries Weed and Grass Killer Concentrate (Torrance, CA), which contains 1.84% diquat dibromide, a herbicide structurally similar to paraquat. He remained asymptomatic for 8 hours, and then a sore throat and vomiting developed. Twenty hours after ingestion, esophagitis, mucositis, epiglottitis, and acute renal failure developed, from which he slowly recovered. This is the first report of systemic diquat toxicity from ingestion of a diluted diquat solution.

Simple method for analysis of diquat in biological fluids and tissues by high-performance liquid chromatography

A simple HPLC method has been described to quantify diquat in biological fluids and tissues. This method permits separation and quantification of diquat from blood, bile, urine, liver and kidney. It does not require special pretreatment of the samples prior to analysis, nor a specially prepared analytical column. Various concentrations of diquat were added (10-300 nmol/ml or g) to fluids or tissues. Analysis of blank samples revealed no substances that interfere with diquat elution. Excellent recovery (95-105%) was obtained. Diquat (120 mumol/kg, i.v.) was injected to rats and quantified in bile, blood and liver. Concentration of diquat was higher in blood and bile than liver. Therefore, this method is applicable for quantification of diquat in toxicological samples, and may be used to determine structurally similar compounds such as paraquat.

Full thickness skin burns secondary to an unusual exposure to diquat dibromide

Diquat dibromide is a commonly used herbicide. The product label cautions against allowing the material to contact the skin as severe skin irritation is possible as well as absorption of the material into the systemic circulation. Waterproof footwear and clothing should be worn to minimize skin contact. A case of full thickness burns of the feet requiring skin grafting occurred following prolonged exposure of the soles of the feet to diquat dibromide.