Delayed death following paraquat poisoning: three case reports and a literature review

Prognosis prediction of procalcitonin within 24 h for acute diquat poisoning

BACKGROUND

To explore the predictive value of procalcitonin (PCT) within 24 h after poisoning for prognosis of acute diquat poisoning.

METHODS

This retrospective study included acute diquat poisoning patients in the Nanyang City Hospital between May 2017 and July 2021.

RESULTS

Among the 45 patients included, 27 survived. The maximum PCT value within 24 h after poisoning was significantly higher in the non-survival patients [9.65 (2.63, 22.77) vs. 0.15 (0.10, 0.50) µg/mL, P < 0.001] compared to the survival patients. The area under the ROC curve (AUC) indicated that the maximum PCT value within 24 h had a good predictive value (AUC = 0.905, 95% CI: 0.808-1.000) compared to ingested quantity (AUC = 0.879, 95% CI: 0.776-0.981), serum creatinine (AUC = 0.776, 95% CI: 0.640-0.912), or APACHE II score (AUC = 0.778, 95% CI: 0.631-0.925). The predictive value of maximum PCT value within 24 h was comparable with blood lactate (AUC = 0.904, 95%CI: 0.807-1.000).

CONCLUSIONS

The maximum PCT value within 24 h after poisoning might be a good predictor for the prognosis of patients with acute diquat poisoning.

Effects of early repeated hemoperfusion combined with hemodialysis on the prognosis of patients with paraquat poisoning

OBJECTIVE

To investigate the effect of early, repeated hemoperfusion in conjunction with hemodialysis on the health status, blood-gas indices, and prognosis of patients with paraquat (PQ) poisoning.

METHODS

In this retrospective study, clinical data of 149 PQ-poisoned patients treated at Xianyang First People's Hospital between January 2019 and January 2022 were analysed. Sixty-two patients who received conventional treatment coupled with early, repeated hemoperfusion were designated as the control group. The remaining 87 patients, who were subjected to additional hemodialysis on the basis of the control group, were designated in the experimental group. A comparison was made between the two groups regarding the changes in liver function, renal function, and blood-gas indices before and after the treatment. Three-month survival outcomes of both groups were analyzed using Cox regression, with survival curves drawn for different prognostic factors.

RESULTS

The experimental group exhibited significantly lower levels of indirect bilirubin (IBiL) and glutamic-pyruvic transaminase (ALT) after the treatment compared to the control group (all P < 0.05), as well as markedly lower levels of total bilirubin (TBil), direct bilirubin (DBil), glutamic-oxaloacetic transaminase (AST), alkaline phosphatase (ALP), urea nitrogen (BUN), and creatinine (Cr) (all P < 0.01). The experimental group also demonstrated significantly improved arterial partial pressure of oxygen (PaO2) and PaO2/inspired oxygen (FIO2) ratios, along with reduced arterial carbon dioxide partial pressure (PaCO2) after the treatment (all P < 0.05). Moreover, a significantly higher three-month survival rate was observed in the experimental group compared to the control group (P < 0.001). According to Cox regression analysis, blood purification mode, age, urine PQ concentration upon admission, the timing of initial gastric lavage and bowl cleanse, and the timing of initial blood purification were identified as independent factors affecting the patients' 90-day prognosis.

CONCLUSION

Early, repeated hemoperfusion coupled with hemodialysis significantly improves the blood-gas indices and liver and kidney function in patients with PQ poisoning, while also extending their short-term survival.

Diagnostic Dilemma in Fatal Paraquat Poisoning: An Autopsy Case Report

Paraquat is a highly toxic agent used as an herbicide worldwide. Despite its easy and widespread availability, data regarding cases of paraquat poisoning in India is limited. Diagnosis often becomes difficult without a clear history, owing to its rather nonspecific and varying presentation. In the present case, a 22-year-old man was brought with a history of high-grade fever, sore throat, and oral ulcers for around a week. He was symptomatically treated at multiple hospitals and was worked up for suspected diagnoses like diphtheria and influenza (H1N1). Later during treatment, it was revealed that "Paraxzone" was procured online by the patient himself two weeks before the onset of his symptoms. Thence, the treatment regimen was modified following suspicion of paraquat poisoning. However, the delay in diagnosis led to the worsening his condition, and the patient succumbed to death due to pulmonary and renal complications after 16 days of survival. The postmortem examination, supplemented with histopathological evaluation, supported the diagnosis of paraquat poisoning. Paraquat poisoning can mimic a myriad of clinical conditions. Thorough history taking, a high degree of suspicion, and collaborative work with the investigating agency are of paramount importance while dealing with cases of suspected paraquat poisoning in hospital settings.

Azocalixarene-Based Supramolecular System for the Detection of Paraquat via an Improved Indicator Displacement Assay

In view of the lethal toxicity of paraquat (PQ) on human health, herein, a simple indicator displacement assay (IDA) based on an azo-modified calixarene host (azoCX[4]) and a fluorophore guest (p-DPD) were elaborately constructed for PQ detection in environmental water samples and plant surfaces. The fluorescent signal of p-DPD in the probe can be quenched by azoCX[4] through a photon-induced electron transfer process and recovered upon the addition of PQ within 10 s. The detection range of the p-DPD@azoCX[4] probe was calculated to be 0.35-8 μM in the Tris-HCl buffer solutions (pH = 7.4). Moreover, this probe exhibited excellent detection selectivity toward PQ over five herbicides (glyphosate, bispyribac, atrazine, ametryn, and bensulfuron methyl), together with anti-interference abilities in the presence of inorganic ions (K⁺, Na⁺, Zn²⁺, Ni²⁺, Li⁺, F^-, Cl^-, Br^-, CO₃^2-, HCO₃^-, and NO₃^-) and amino acids (Asp, Arg, Glu, Ala, and Cys). Particularly, the probe was successfully used to detect PQ in real water samples with acceptable accuracy and showed potential applications for on-site detection with paper-based test strips and on the leaf surface. We believe that this simplified IDA-based probe provided an effective detecting tool for PQ, and the design strategy would guide the further development of new IDA sensing systems.

Rare fatal poisoning through dermal exposure to paraquat

Paraquat skin contact occurs less frequently and is rarely fatal. This article reports a case of a 45-year-old man who presented with dysphagia, respiratory distress and grade two, and third skin burns focusing on the upper body after accidental exposure to paraquat. He was admitted to the hospital 6 days after the first contact. The urine sodium dithionate test was strongly positive. The O₂ saturation at admission was 52%, which reached 91% with a bag valve mask. Rising blood liver enzymes, urea, creatinine, and respiratory acidosis in the venous blood gas analysis were observed in the lab data. In the course of hospitalization, the patient was intubated due to oxygen level dropping. Evidence of acute respiratory distress syndrome and decreased level of consciousness was also observed. However, despite treatment with corticosteroids, antioxidants, and hemodialysis, he died on the fourth day of hospitalization. It is concluded that dermal exposure with paraquat could be life-threatening if the patient presented late with organ involvement.

Adsorption of Cationic Pollutants from Water by Cotton Rope Coated with Cyclodextrin Polymers

The contamination from perilous organic compounds (pesticide and dyes) in water generates a significant problem for the environment and humans. A modified textile was prepared by a coating of anionic cyclodextrin polymer, obtained from the cross-linking between citric acid and β-cyclodextrin in the presence of poly (vinyl alcohol), on the cotton cord for cationic pollutant removal from an aqueous solution. Its physicochemical properties were also characterized by gravimetry, titration, stereomicroscopy, SEM, TGA, ¹³C NMR, and ATR-FTIR. The CC2 system exhibited 79.2% coating yield, 1.12 mmol/g COOH groups, 91.3% paraquat (PQ) removal, 97.0% methylene blue (MB) removal, and 98.3% crystal violet (CV) removal for 25 mg/L of initial concentration. The kinetics was fitted to the pseudo-second-order model using 6 h of contact time. The isotherm was suitable for the Langmuir isotherm with a maximum adsorption of 26.9 mg/g (PQ), 23.7 mg/g (MB), and 30.3 mg/g (CV). After 120 h of contact time in water and 5% v/v of HCI in ethanol, the weight loss was 7.5% and 5.6%, respectively. Finally, the recyclability performance reached 84.8% (PQ), 95.2% (MB), and 96.9% (CV) after five reuses.

Ginkgolide C Alleviates Acute Lung Injury Caused by Paraquat Poisoning via Regulating the Nrf2 and NF-κB Signaling Pathways

Paraquat (PQ), a highly toxic herbicide and primary attack for lung, results in severe acute lung injury (ALI) appeared as evident oxidative stress, inflammation, and apoptosis. Increasing evidence elucidates that nuclear factor erythroid-2-related factor 2 (Nrf2) and its associated nuclear factor-κB (NF-κB) exhibit many merits for protection of ALI by coordinating a fine-turned response to oxidative stress, inflammation, and apoptosis. Ginkgolide C (GC) has been reported to be a safe and potent therapeutic agent against ALI. However, whether GC could protect ALI induced by PQ poisoning and the possible underlining mechanisms have remained not to be fully elucidated. A rat model of ALI and a model of acute type II alveolar epithelial cell (RLE-6TN) injury constructed by exposure to PQ were applied to discuss the protective effect of GC. Furthermore, Nrf2 gene silencing RLE-6TN cells were used to discuss the exact mechanism. We confirmed that GC significantly ameliorated the histopathological damages, ultrastructural changes, lung injury score, W/D ratio, and Hyp activity of lung tissue and inhibited polymorphonuclear neutrophil (PMN) infiltration after PQ poisoning. Further results revealed that GC remarkably activated Nrf2-based cytoprotective system and inhibited NF-κB-induced inflammatory injury as well as apoptosis. Taken together, we concluded that GC preserved protection of PQ-induced ALI via the Nrf2-NF-κB dependent signal pathway, which may provide us novel insights into the treatment strategies for PQ poisoning.

Cotton Cord Coated with Cyclodextrin Polymers for Paraquat Removal from Water

The contamination of hazardous agrochemical substances in water caused essential trouble for humans and the environment. The functional textile was used as an effective adsorbent for paraquat removal from an aqueous solution. The coating of anionic cyclodextrin polymer, issued from the cross-linking between 1,2,3,4-butanetetracarboxylic acid and β−cyclodextrin in the presence of poly (vinyl alcohol), on the cotton cord, was firstly investigated. Their physicochemical characteristics were also characterized by gravimetry, acid–base titration, ATR-FTIR, ¹³C NMR, TGA, and stereo-microscopy. The BDP5 system revealed 107.3% coating yield, 1.13 mmol/g COOH groups, and 95.1% paraquat removal for 25 mg/L of initial concentration. The pseudo-second-order model was appropriate for kinetics using 6 h of contact time. Langmuir isotherm was suitable with the maximum adsorption of 30.3 mg/g for paraquat adsorption. The weight loss was 10.7% and 7.8%, respectively, for water and 5% v/v of HCI in ethanol after 120 h of contact time. Finally, the reusability efficiency stayed at 88.9% after five regeneration.

Adsorption of Cationic Contaminants by Cyclodextrin Nanosponges Cross-Linked with 1,2,3,4-Butanetetracarboxylic Acid and Poly(vinyl alcohol)

Cationic organic pollutants (dyes and pesticides) are mainly hydrosoluble and easily contaminate water and create a serious problem for biotic and abiotic species. The elimination of these dangerous contaminants from water was accomplished by adsorption using cyclodextrin nanosponges. These nanosponges were elaborated by the cross-linking between 1,2,3,4-butanetetracarboxylic acid and β-cyclodextrin in the presence of poly(vinyl alcohol). Their physicochemical characteristics were characterized by gravimetry, acid-base titration, TGA, 13C NMR, ATR-FTIR, Raman, X-ray diffraction, and Stereomicroscopy. The BP5 nanosponges displayed 68.4% yield, 3.31 mmol/g COOH groups, 0.16 mmol/g β-CD content, 54.2% swelling, 97.0% PQ removal, 96.7% SO removal, and 98.3% MG removal for 25 mg/L of initial concentration. The pseudo-second-order model was suitable for kinetics using 180 min of contact time. Langmuir isotherm was suitable for isotherm with the maximum adsorption of 120.5, 92.6, and 64.9 mg/g for paraquat (PQ), safranin (SO), and malachite green (MG) adsorption, respectively. Finally, the reusability performance after five regeneration times reached 94.1%, 91.6%, and 94.6% for PQ, SO, and MG adsorption, respectively.

5‑Aminosalicylic acid attenuates paraquat‑induced lung fibroblast activation and pulmonary fibrosis of rats

Pulmonary fibrosis is one of the most important pathological processes associated with paraquat (PQ) poisoning. 5‑Aminosalicylic acid (5‑ASA) has been shown to be a promising agent against fibrotic diseases. In the present study, the alleviating role of 5‑ASA was evaluated in a rat model of pulmonary fibrosis induced by PQ intragastric poisoning (80 mg/kg). Wistar rats were divided into control, PQ, 5‑ASA (30 mg/kg daily, 14 days) and PQ + 5‑ASA groups. Histological examination revealed congestion, edema and inflammatory cell infiltration in the bronchial and alveolar walls at 3 days after PQ exposure. Alveolar septum thickening with alveolar lumen narrowing was observed at 14 days, while fibroblast proliferation, increase in collagen fiber number and fibrous thickening of the alveolar walls were observed at 28 day. All the aforementioned pulmonary injury changes in the PQ group were attenuated in the PQ + 5‑ASA group. Hydroxyproline (HYP) content increased in the lung tissues of the rats at 14 days after PQ treatment and reached a peak at 28 days. Compared with the PQ group, HYP contents of lung tissue decreased at 14 and 28 days after PQ + 5‑ASA treatment. Masson's trichrome staining revealed that the increase in the amount of collagen fibers in the lung tissues of rats in the PQ group was inhibited by 5‑ASA treatment, further confirming the alleviating effect of 5‑ASA on fibrosis. In addition, the results showed that 5‑ASA attenuated the upregulation of transforming growth factor‑β1 and phosphorylated‑SMAD3, and the reduction of peroxisome proliferator activated receptor γ induced by PQ in lung tissue of rats and human lung fibroblast WI‑38 VA13 cells. In conclusion, the results suggested that 5‑ASA had an alleviating effect on PQ‑induced pulmonary fibrosis, partly by suppressing the activation of the TGF‑β1 signaling pathway.

Adsorption of Paraquat by Poly(Vinyl Alcohol)-Cyclodextrin Nanosponges

The contamination of hydrosoluble pesticides in water could generate a serious problem for biotic and abiotic components. The removal of a hazardous agrochemical (paraquat) from water was achieved by adsorption processes using poly(vinyl alcohol)-cyclodextrin nanosponges, which were prepared with various formulations via the crosslinking between citric acid and β-cyclodextrin in the presence of poly(vinyl alcohol). The physicochemical properties of nanosponges were also characterized by different techniques, such as gravimetry, thermogravimetry, microscopy (SEM and Stereo), spectroscopy (UV-visible, NMR, ATR-FTIR, and Raman), acid-base titration, BET surface area analysis, X-ray diffraction, and ion exchange capacity. The C10D-P2 nanosponges displayed 60.2% yield, 3.14 mmol/g COOH groups, 0.335 mmol/g β-CD content, 96.4% swelling, 94.5% paraquat removal, 0.1766 m2 g-1 specific surface area, and 5.2 × 10-4 cm3 g-1 pore volume. The presence of particular peaks referring to specific functional groups on spectroscopic spectra confirmed the successful polycondensation on the reticulated nanosponges. The pseudo second-order model (with R2 = 0.9998) and Langmuir isotherm (with R2 = 0.9979) was suitable for kinetics and isotherm using 180 min of contact time and a pH of 6.5. The maximum adsorption capacity was calculated at 112.2 mg/g. Finally, the recyclability of these nanosponges was 90.3% of paraquat removal after five regeneration times.

A review on the pharmacokinetic properties and toxicity considerations for chloroquine and hydroxychloroquine to potentially treat coronavirus patients

The SARS-CoV-2 virus, caused a novel emerged coronavirus disease, is growing rapidly worldwide. Few studies have evaluated the efficacy and safety of Chloroquine (CQ), an old antimalarial drug, and Hydroxychloroquine (HCQ) in the treatment of COVID-19 infection. HCQ is derived from CQ by adding a hydroxyl group into it and is a less toxic derivative of CQ for the treatment of COVID-19 infection because it is more soluble. This article summarizes pharmacokinetic properties and toxicity considerations for CQ and HCQ, drug interactions, and their potential efficacy against COVID-19. The authors also look at the biochemistry changes and clinical uses of CQ and HCQ, and supportive treatments following toxicity occurs. It was believed that CQ and HCQ may provide few benefits to COVID-19 patients. A number of factors should be considered to keep the drug safe, such as dose, in vivo animal toxicological findings, and gathering of metabolites in plasma and/or tissues. The main conclusion of this review is that CQ and HCQ with considered to their ADMET properties has major shortcomings and fully irresponsible.

Can kissing cause paraquat poisoning: A case report and review of literature

BACKGROUND

Paraquat is an effective, broad-spectrum, highly toxic quaternary ammonium herbicide. Paraquat poisoning has been reported frequently in recent years. It has severe lung, kidney, liver, and nervous system toxicity, and there is currently no specific antidote. Paraquat poisoning may follow ingestion, inhalation, and skin contact. There have been no previous reports of paraquat poisoning that resulted from kissing. This rare case provides a new reference for the prevention of paraquat poisoning.

CASE SUMMARY

A 27-year-old man came to the emergency department complaining that he had come into contact with paraquat by kissing his girlfriend, who had taken 80-120 mL 20% paraquat. After admission, his lung computed tomography (CT) showed increased lung markings. Redness and a burning sensation developed on his tongue, which progressed to painful erosions and coalescent ulcers. The final diagnosis was mild paraquat poisoning. Anti-inflammatory, antioxidant, and symptomatic treatment were initiated and continued for 7 d. Dyspnea did not occur, subsequent lung CT showed no significant changes, and the tongue pain was slightly improved. One month after discharge, the tongue injury was resolved.

CONCLUSION

This case indicated that the tongue and lung tissues are particularly vulnerable to paraquat toxicity, even after a limited exposure.

Cytoprotective Activity of p-Terphenyl Polyketides and Flavuside B from Marine-Derived Fungi against Oxidative Stress in Neuro-2a Cells

The influence of p-terphenyl polyketides 1-3 from Aspergillus candidus KMM 4676 and cerebroside flavuside B (4) from Penicillium islandicum (=Talaromyces islandicus) against the effect of neurotoxins, rotenone and paraquat, on Neuro-2a cell viability by MTT and LDH release assays and intracellular ROS level, as well as DPPH radical scavenging activity, was investigated. Pre-incubation with compounds significantly diminished the ROS level in rotenone- and paraquat-treated cells. It was shown that the investigated polyketides 1-3 significantly increased the viability of rotenone- and paraquat-treated cells in two of the used assays but they affected only the viability of paraquat-treated cells in the LDH release assay. Flavuside B statistically increased the viability of paraquat-treated cells in both MTT and LDH release assays, however, it increased the viability of rotenone-treated cells in the LDH release assay. Structure-activity relationships for p-terphenyl derivatives, as well as possible mechanisms of cytoprotective action of all studied compounds, were discussed.

Lanostane Triterpenoid Metabolites from a Penares sp. Marine Sponge Protect Neuro-2a Cells against Paraquat Neurotoxicity

The results of an investigation of the protective effects of five lanostane triterpenoids: 3β-acetoxy-7β,8β-epoxy-5α-lanost-24-en-30,9α-olide (1), 3β-hydroxy-7β,8β-epoxy-5α-lanost-24-en- 30,9α-olide (2), 29-nor-penasterone (3), penasterone (4), and acetylpenasterol (5), from a marine sponge, Penares sp., against paraquat-induced neuroblastoma Neuro-2a cell damage, are described. The influence of all compounds on viability of the Neuro-2a cells treated with paraquat (PQ) was studied with MTT and fluorescein diacetate assays as well as propidium iodide straining. 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity of the compounds as well as their influence on reactive oxygen species (ROS) level and mitochondrial membrane potential in PQ-treated neuronal cells were analyzed. Finally, the effect of the compounds on intracellular level of heat shock protein 70 kDa (Hsp70) and neurite outgrowth in PQ-treated Neuro-2a cells were studied. Studied triterpenoids demonstrated protective effects against PQ-induced neurotoxicity associated with the ability to reduce ROS intracellular level and diminish mitochondrial dysfunction. Acetylpenasterol (5), as a more promising neuroprotective compound, significantly increased the viability of Neuro-2a cells incubated with PQ as well as decreased intracellular ROS level in these cells. Moreover, acetylpenasterol induced Hsp70 expression in PQ-treated cells. It was also shown to inhibit PQ-induced neurite loss and recovered the number of neurite-bearing cells. The relationship between neuroprotective activity of the investigated compounds 1–5 and their chemical structure was also discussed.

Paraquat exposure over generation affects lifespan and reproduction through mitochondrial disruption in C. elegans

Paraquat (methyl viologen), is a non-selective contact herbicide and well known mitochondrial toxicant. Mitochondria are the center of cellular metabolism, and involved in the development, lifespan, and reproduction of an organism. Mitochondria are dynamic organelles that are inherited maternally through the germline and carry multiple copies of their own genome (mtDNA). It is important to understand the effects of acute and chronic stress caused by mitochondrial toxicants over multiple generations at the cellular and organism levels. Using the model nematode C. elegans, we show that acute and chronic exposure to paraquat affects reproduction, longevity, gene expression, and mitochondrial physiology. Acute exposure to paraquat in N2 (wild type) causes induction of mitochondrial unfolded protein response (mtUPR), increased expression of mitochondrial superoxide dismutase, decreased mitochondrial membrane potential (Δψm), a dose-dependent progression from linear to fragmented mitochondria, and dose-dependent changes in longevity. Chronic exposure to a low dose of paraquat (0.035 mM) over multiple generations in N2 causes a progressive decline of fertility, leading to complete loss of fertile embryo production by the third generation. The mutation in CEP-1 [cep-1(gk138)], a key regulator of stress-induced apoptosis in the germline, causes increased sensitivity to chronic paraquat relative to N2 with no fertile embryo production beyond the second generation. Whereas, mitochondrial electron transport chain (complex III) mutant [isp-1(qm150)], which display constitutive activation of mtUPR showed increased tolerance and produced fertile embryo out to the fourth generation. The N2, cep-1(gk138), and isp-1(qm150) strain's lifespan over multiple generations exposed to chronic paraquat were measured. Fertility and lifespan data together indicate a trade-off between reproduction and somatic maintenance during chronic paraquat exposure. We have proposed that mitochondrial signaling, dynamics, and CEP-1 mediated germline apoptosis is involved in this trade-off.

ADME and toxicity considerations for tramadol: from basic research to clinical implications

INTRODUCTION

Tramadol is widely being used in chronic pain management for improving patients' life quality and reducing trauma. Although it is listed in several medicinal guidelines, its use is controversial because of the conflicting results obtained in pharmacokinetic/pharmacodynamic studies. This multi-receptor drug acts as µ₁ opioid receptor agonist, monoamine reuptake inhibitor, and inhibitor of ligand-gated ion channels and some special protein-coupled receptors.

AREAS COVERED

This review provides a comprehensive view on the pharmacokinetic, pharmacodynamic, and toxicity of tramadol with a deep look on its side effects, biochemical and pathological changes, and possible drug interactions. In addition, the main ways of tramadol poisoning management describe according to in vivo and clinical trial studies.

EXPERT OPINION

Given the broad spectrum of targets, increasing the cases of overdoses and toxicity, and probable drugs interaction, it is necessary to take another look at the pharmacology of tramadol. Regarding the adverse effects of tramadol on different tissues, especially the nervous system and liver tissue, more attentions to tramadol metabolites, their interaction with other drugs, and active agents seem critical. Seizure as the most cited effect of tramadol and its destructive effects on tissues would alleviate by co-administration with drugs with antioxidant properties.

Oxidative stress delays development and alters gene expression in the agricultural pest moth, Helicoverpa armigera

Stress is a widespread phenomenon that all organisms must endure. Common in nature is oxidative stress, which can interrupt cell homeostasis to cause cell damage and may be derived from respiration or from environmental exposure through diet. As a result of the routine exposure from respiration, many organisms can mitigate the effects of oxidative stress, but less is known about responses to oxidative stress from other sources. Helicoverpa armigera is a major agricultural pest moth that causes significant damage to crops worldwide. Here, we examined the effects of oxidative stress on H. armigera by chronically exposing individuals to paraquat-a free radical producer-and measuring changes in development (weight, developmental rate, lifespan), and gene expression. We found that oxidative stress strongly affected development in H. armigera, with stressed samples spending more time as caterpillars than control samples (>24 vs. ~15 days, respectively) and therefore living longer overall. We found 1,618 up- and 761 down-regulated genes, respectively, in stressed versus control samples. In the up-regulated gene set, was an over-representation of biological processes related to cuticle and chitin development, glycine metabolism, and oxidation-reduction. Oxidative stress clearly impacts physiology and biochemistry in H. armigera and the interesting finding of an extended lifespan in stressed individuals could demonstrate hormesis, the phenomenon whereby toxic compounds can actually be beneficial at low doses. Collectively, our findings provide new insights into physiological and gene expression responses to oxidative stress in invertebrates.

Where ferroptosis inhibitors and paraquat detoxification mechanisms intersect, exploring possible treatment strategies

Paraquat (PQ) is a fast-acting and effective herbicide that is used throughout the world to eliminate weeds. Over the past years, PQ was considered one of the most popular poisoning substances for suicide, and PQ poisoning accounts for about one-third of suicides around the world. Poisoning with PQ may cause multiorgan failure, pulmonary fibrosis, and ultimately death. Exposure to PQ results in the accumulation of PQ in the lungs, causing severe damage and, eventually, fibrosis. Until now, no effective antidote has been found to treat poisoning with PQ. In general, the toxicity of PQ is due to the formation of high energy oxygen free radicals and the peroxidation of unsaturated lipids in the cell. Ferroptosis is the result of the loss of glutathione peroxidase 4 (GPX4) activity that transforms iron-dependent lipid hydroperoxides to lipid alcohols, which are inert in the biological environment. Impaired iron metabolism and lipid peroxidation are increasingly known as the driving agents of ferroptosis. The contribution of ferroptosis to the development of cell death during poisoning with PQ has not yet been addressed. There is growing evidence about the relationship between PQ poisoning and ferroptosis. This raises the possibility of using ferroptosis inhibitors for the treatment of PQ poisoning. In this hypothesis-driven review article, we elaborated how ferroptosis inhibitors might circumvent the toxicity induced by PQ and may be potentially useful for the treatment of PQ toxicity.

Evaluation of gastric lavage efficiency and utility using a rapid quantitative method in a swine paraquat poisoning model

BACKGROUND

Gastric lavage (GL) is one of the most critical early therapies for acute paraquat (PQ) poisoning; however, details of the treatment protocol remain to be established.

METHODS

A rapid quantitative method involving sodium dithionite testing was developed. It was validated for the determination of the PQ concentrations in gastric juice and eluate samples from a swine acute PQ poisoning model with early or delay GL, or without. The vital signs, laboratory testing, and PQ plasma concentrations were collected for therapeutic effect evaluation.

RESULTS

The reaction conditions of the test were optimized for two types of samples. Early GL at one hour (H1) could improve the signs and symptoms after acute PQ poisoning at 24 hours (H24). In contrast, GL at 6 hours (H6) could only partially relieve the vital signs. The H1 GL group effectively reduced the peak of the plasma PQ concentration. In addition, the PQ concentrations in the plasma and the gastric juice were significantly decreased in both the GL groups as compared to the untreated group at H24. Moreover, there was no significant difference in the washing efficiencies calculated from the total eluates between the two GL groups. However, the washing efficiency of the first 10 L eluate is superior to that of the additional 10 L eluate.

CONCLUSION

GL only at early stage may it benefit PQ poisoning in an animal model. The currently used 20 L GL volume may need to be reduced in view of the low washing efficiency in the later 10 L eluate. The rapid quantitative method can be used for gastric juice sample and has a certain value for clinical GL practices.

Paraquat Degradation From Contaminated Environments: Current Achievements and Perspectives

Paraquat herbicide has served over five decades to control annual and perennial weeds. Despite agricultural benefits, its toxicity to terrestrial and aquatic environments raises serious concerns. Paraquat cannot rapidly degrade in the environment and is adsorbed in clay lattices that require urgent environmental remediation. Advanced oxidation processes (AOPs) and bioaugmentation techniques have been developed for this purpose. Among various techniques, bioremediation is a cost-effective and eco-friendly approach for pesticide-polluted soils. Though several paraquat-degrading microorganisms have been isolated and characterized, studies about degradation pathways, related functional enzymes and genes are indispensable. This review encircles paraquat removal from contaminated environments through adsorption, photocatalyst degradation, AOPs and microbial degradation. To provide in-depth knowledge, the potential role of paraquat degrading microorganisms in contaminated environments is described as well.