Discernment scheme for paraquat poisoning: A five-year experience in Shiraz, Iran

Ameliorative Potential of Sudachitin Against Paraquat Induced Renal Toxicity in Rats Via Regulating Nrf2/Keap1 Pathway: An Inflammatory, Apoptotic and Histopathological Assessment

Paraquat (PQ) is a noxious herbicide which is well known for its adverse effects on vital organs including kidneys. Sudachitin (SCN) is a plant derived flavone that is obtained from Citrus sudachi and demonstrates a range of pharmacological potentials. This investigation was executed to assess the protective effects of SCN to counteract PQ instigated renal damage in albino rats (Rattus norvegicus). Twenty-four rats were apportioned in 4 different groups i. e., control group, PQ (5 mg/kg) intoxicated group, PQ (5 mg/kg)+SCN (20 mg/kg) cotreated group and SCN (20 mg/kg) only administrated group. Our findings revealed that exposure to PQ reduced the expressions of Nrf2 (nuclear factor erythroid 2-related factor 2) and its cytoprotective genes while escalating the expression of keap1. Furthermore, PQ intoxication reduced the activities of superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GSR), heme-oxygenase-1 (HO-1) and glutathione (GSH) contents while increasing the levels of malondialdehyde (MDA) and reactive oxygen species (ROS). Moreover, PQ exposure significantly increased the levels of neutrophil gelatinous-associated lipocalin (NGAL), urea, kidney injury molecule-1(KIM-1) as well as creatine while reducing creatine clearance. Additionally, PQ upregulated the levels of inflammatory markers including interleukin-6 (IL-6), tumor necrosis- α (TNF- α), nuclear factor- κB (NF-κB), interleukin 1beta (IL-1β), and cyclo-oxygenase-2 (COX-2). Moreover, PQ administration upregulated the expression of Bax (Bcl-2-associated X protein) and (cysteine-aspartic acid protease) Caspase-3 while downregulating the expressions of (B-cell lymphoma 2 protein) Bcl-2. Besides, PQ exposure prompted various histopathological damages in renal tissues. Nonetheless, SCN substantially restored aforementioned alterations in the renal tissues owing to its anti-oxidative, anti-inflammatory and anti-apoptotic potential.

Situation Analysis of Suicide and Self-Harm in the WHO Eastern Mediterranean Region

OBJECTIVE

An estimated 41,000 lives are lost to suicide each year in World Health Organization Eastern Mediterranean Region Office (WHO EMRO) countries. The objective of this study was to conduct a situation analysis for suicide and self-harm in the WHO EMRO region.

METHODS

Data on suicide were obtained from the WHO Global Health Estimates for the years 2000-2019. Information on risk groups efforts to prevent self-harm and suicide in the EMRO region were retrieved through scientific studies, grey literature, and public websites.

RESULTS

During 2000-2019, the age-standardized suicide rate was 6.7 per 100,000 inhabitants, albeit there are concerns regarding data quality. Self-harm and suicide remain criminal acts in more than half of the countries. Few countries have a national plan for prevention of suicide. Toxic agents, such as pesticides and black henna, are easily available and frequently used for suicide in some areas, as are firearms and self-immolation. Successful prevention measures include means restriction and psychosocial interventions after self-harm.

CONCLUSION

Many WHO EMRO countries remain underserved in terms of mental health care. Decriminalization of suicide and means restriction might be further promoted. Online-based tools for mental health literacy and psychosocial therapy are other options to explore.

Occupational respiratory disorders in Iran: a review of prevalence and inducers

The link between occupational respiratory diseases (ORD) and exposure to harmful factors that are present in the workplace has been well shown. Factors such as physical activity, age and duration of occupational exposure playing important roles in ORD severity, should be identified in the workplace, their effects on workers health should be studied, and ultimately, exposure to them must be minimized. We carried out a literature review by searching PubMed, Scopus, and Web of Science databases to retrieve studies published from 1999 until the end of April 2023 reporting the prevalence and inducers of ORD in Iran. In Iranian workers, several ORD such as interstitial lung disease, silicosis, occupational asthma, pulmonary inflammatory diseases, chronic obstructive pulmonary diseases, and lung cancers have been reported. It was indicated that ORD mainly occur due to repeated and prolonged exposure to noxious agents in the workplace. We also extracted the prevalence of ORD in different regions of Iran from the retrieved reports. Based on our literature review, the prevalence of ORD among Iranian workers highlights the importance of regular assessment of the risk of exposure to noxious agents in the workplace to develop measures for preventing potential adverse effects.

Dimethyl fumarate attenuates paraquat-induced pulmonary oxidative stress, inflammation and fibrosis in mice

Paraquat (PQ) is the most important cationic bipyridyl herbicide in the agricultural industry, which is very toxic to humans and animals and causes disruption in many organs, mainly in the lungs. Dimethyl fumarate (DMF) is an immune-modulating drug used in the treatment of multiple sclerosis and psoriasis shows antioxidant, anti-inflammatory, and antifibrotic effects. In this study, the ameliorative effects of DMF (10, 30 and 100 mg/kg, orally) on PQ (30 mg/kg) model of lung damage were evaluated in male mice. DMF was given daily for 7 days and PQ was administrated in the fourth day in a single dose. On the eighth day, the animals were sacrificed, and their lung tissue were removed. The results indicated that DMF can ameliorate PQ-induced the significant increase in lung index, hydroxyproline, as well as TBARS, TGF-β, NF-κB and decrease in the amount of total thiol, catalase, glutathione peroxidase, superoxide dismutase, Nrf-2, and INF-γ. The histopathological results confirmed indicated findings. The results showed that the protective effect of DMF on PQ-induced toxicity is mediated through antioxidant, anti-inflammatory and antifibrotic activities.

Serum creatinine in predicting mortality after paraquat poisoning: A systematic review and meta-analysis

Although the prognostic value of blood creatinine levels in patients with paraquat (PQ) poisoning has been studied for a long time, the results are still controversial. Therefore, we performed the first meta-analysis to comprehensively assess the value of blood creatinine in predicting the prognosis of patients with PQ poisoning. We searched PubMed, EMBase, Web of Science, ScienceDirect, Cochrane Library, China National Knowledge Infrastructure, China Science and Technology Journal Database, and China Online Journals to identify all relevant papers published up to June 2022. Data were extracted for pooled analysis, heterogeneity testing, sensitivity analysis, publication bias analysis, and subgroup analysis. Ultimately, 10 studies involving 862 patients were included. The I2 of diagnostic odds ratio (DOR), sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of this study were all greater than 50%, which showed the existence of heterogeneity in this study, and a random effects model was used for the combination of the above five effect sizes. Pooled analysis showed a high predictive value of blood creatinine for prognosis of PQ poisoning [pooled DOR:22.92, 95% confidence interval (CI):15.62-33.65, P < 0.001]. The combined sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio were 86% (95% CI: 0.79-0.91), 78% (95% CI: 0.69-0.86), 4.01 (95% CI: 2.81-5.71), and 0.17 (95% CI: 0.12-0.25), respectively. Deeks publication bias test revealed there was publication bias. Sensitivity analysis showed no significant differences in the estimates of impact. Serum creatinine is an effective predictor of mortality in patients with PQ poisoning.

The efficacy of hemodialysis on paraquat poisoning mortality: A systematic review and meta-analysis

BACKGROUND

Paraquat (PQ) poisoning is a serious public health concern, especially in developing countries, due to its easy access and lack of awareness of potential harms. No effective treatment has been reported yet. Conventional hemodialysis (HD) is still used in many centers for excreting PQ or reducing acute kidney injury, but there is no consensus on its efficacy. Therefore, we aimed to review the HD efficacy in PQ poisoning mortality.

MATERIALS AND METHODS

We searched Web of Science, PubMed, Excerpta Medical Database, Google Scholar, Scopus, Cochrane, Web of Knowledge, Pro-Quest, ScienceDirect, Springer, Clinical Key, Scientific Information Database, Magiran, and Iran-doc, in publications before January 1, 2020. We compared patients who underwent HD (Group 1) with those who did not (Group 2). The outcome was considered mortality/survival. The data were analyzed by Comprehensive Meta-analysis Software.

RESULTS

This systematic review and meta-analysis included five studies with a combined total of 203 patients. The patients in the Group 1 had higher mortality than Group 2 (odds ratio, 2.84; 95% confidence interval: 1.22-6.64; P = 0.02). There was no evidence of publication bias (P value for Egger's test = 0.833).

CONCLUSION

Although HD did not affect the survival of patients, other variables such as the amount of ingested PQ, poisoning severity, the time between PQ ingestion and the start of HD, duration, and times of HD sessions may influence the results regarding mortality.

Paraquat induced oxidative stress, DNA damage, and cytotoxicity in lymphocytes

Paraquat (PQ) is a herbicide belonging to the group of bipyridylium salts. The objective of this study was to evaluate oxidative stress, DNA damage, and cytotoxicity induced by paraquat in peripheral lymphocyte cells in vivo as well as pathological changes in various tissues. For this purpose, 28 male Wistar rats in 6 different groups were poisoned by paraquat gavage and blood samples were taken from the hearts of rats after during the poisoning period. Oxidative stress, DNA damage, cell membrane integrity, serum lactate dehydrogenase, and cytotoxicity, were investigated by Ferric Reducing Antioxidant Potential (FRAP) test, alkaline comet assay, measuring serum lactate dehydrogenase (LDH), Hoechst staining and flow cytometry with propidium iodide (PI) respectively. The lung, kidney, and liver tissues were also examined pathologically. Paraquat caused dose-dependent DNA damage in peripheral lymphocyte cells and significant oxidative cell membrane damage. The most damage was caused by a single dose of 200 mg/kg b.w of paraquat by gavage. The gradual exposure to a dose of 300 mg/kg b.w of paraquat showed less damage, which could be due to the activation of the antioxidant defense mechanism.

•

Paraquat induced oxidative stress.

•

Paraquat increases serum lactate dehydrogenase.

•

Oxidative stress Inducted by exposure to paraquat Inducted DNA damage.

Paraquat poisoning in Andaman and Nicobar Islands - Government must intervene

Paraquat poisoning is a grave public health problem in the Andaman and Nicobar islands of India. To evaluate various aspects of paraquat poisoning that influence the outcome, a retrospective study was planned. In this case series study, the information about all cases of acute paraquat poisoning who were admitted to GB Pant Hospital, Port-Blair, in a 12-year period (January 2007-December 2018) were evaluated. A total of 29 referred patients were evaluated with the majority from the early productive age of 16-30 years (68.97%). The case fatality rate was 100%. Most of the incidents took place in South Andaman district (68.97%) and during the rainy season (55.17%). Initially, they presented with local symptoms like mouth and throat pain with ulceration (48.27%), vomiting (44.82%), breathlessness (34.48%), epigastric and abdominal pain (31.03%), hematemesis (27.58%), and oliguria (20.68%). Later on, major organ dysfunctions like a respiratory failure (65.51%), acute kidney injury (62.08%), acute liver failure (55.17%), cardiac dysfunction (31.03%), and multiorgan failure (58.62%) ensued. Patients who were referred early had a significantly longer hospital stay. Few received advanced care, like, methyl prednisolone (24.12%), cyclophosphamide (10.34%), Mesna/NAC (06.89%), charcoal tablets (10.34%), mechanical ventilation (06.89%), and hemodialysis (10.34%). Apart from hemodialysis in acute kidney injury patients and steroid pulse, no other modalities showed improved hospital survival duration. Primary prevention especially government laws, public awareness, and education of health professionals regarding the seriousness of this problem are the keys to get rid of this incurable poisoning in these islands. The government should prioritize preventive works in the south Andaman district and during the rainy season to avoid catastrophe each year and if possible should ban it. Methyl prednisolone therapy and hemodialysis might be advocated to have a better outcome.

Investigation of simple, objective, and effective indicators for predicting acute paraquat poisoning outcomes

Initial symptoms of paraquat (PQ) toxicity are often not obvious, and the lack of advanced testing equipment and medical conditions in the primary hospital make it difficult to provide early diagnosis and timely treatment. To explore simple, objective, and effective indicators of prognosis for primary clinicians, we retrospectively analyzed acute PQ poisoning in 190 patients admitted to our hospital from 2008 to 2017. Based on their condition at the time of discharge, patients were categorized into either the survival group (n = 71) or the mortality group (n = 119). Age, PQ ingested amount, urinary PQ, urinary protein, white blood cell (WBC), and serum creatinine (Cr) were the key factors associated with the prognosis for PQ poisoning. We identified specific diagnostic thresholds for these key indicators of PQ poisoning: PQ ingested amount (36.50 mL), urinary PQ (semiquantitative result "++"), urinary protein (semiquantitative result "±"), WBC (16.50 × 10⁹/L), and serum Cr (102.10 µmol/L). Combining these five indicators to identify poisoning outcomes was considered objective, accurate, and convenient. When the combined score was <1, the predicted probability of patient death was 6%. When the combined score was ≥3, the predicted probability of patient death was 96%. These findings provide metrics to assist primary clinicians in predicting outcomes of acute PQ poisoning at earlier stages, a basis for administering treatment.

Exploration of therapeutic role of montelukast and dexamethasone combination against paraquat induced inhalational toxicity

OBJECTIVES

To explore the therapeutic role of a single dose combination of montelukast (MON) and dexamethasone (DXM) through intra-peritoneal route against paraquat (PQ)-intoxicated experimental Wistar rats.

METHODS

In vivo the survival rate was investigated following the administration of both MON and DXM in PQ exposed rats. Lungs parameters including enhanced pause (Penh), tidal volume (TV) and breath per minute (BPM) were determined using the whole body plethysmograph (WBP). Further chest imaging and histopathological studies were conducted to evaluate the lungs injury. In vivo the antioxidant activity was carried out by determining the levels of catalase (SOD), superoxide dismutase (CAT) and glutathione peroxidase (GSH-Px). Lungs tissue concentration of different proinflammatory cytokines like IL-1β, IL-6, TGF-β1 and TNF-α was also determined. Finally, expression of NF-kB and p-NF-kB was investigated by western blot.

RESULTS

Results of survival rate and levels of lungs parameters indicated therapeutic potential of combination treatment of MON and DXM. Protective activity on lungs was reflected in chest imaging and histopathological investigations. Moreover, combination treatment exhibited significant increased levels of all anti-oxidant parameters. Significant decrease in the levels of IL-1β; IL-6; TGF-β1 and TNF-α was also observed with the combination treatment of MON and DXM. Evidence of significant down regulation of NF-kB and phospho-NF-kB was also found with the combination treatment of MON and DXM.

CONCLUSIONS

Given the advantage of therapeutic synergism activity of MON and DXM, it may be used in the prophylaxis of PQ-intoxication following clinical trials.

Ventilator settings and outcome of respiratory failure in paraquat-induced pulmonary injury

Paraquat is a nonselective contact herbicide that has significant importance in clinical toxicology due to its high mortality rate. The cause of mortality in the acute phase of poisoning is a multi-organ failure while in the sub-acute phase is alveolar injury and lung fibrosis. The aim of this study was to evaluate the advantages and drawbacks of mechanical ventilation (MV) in paraquat-induced pulmonary injury and its consequential respiratory failure (PIPI-CRF). This retrospective descriptive analytical study was done to investigate the outcome of patients who had developed PIPI-CRF and underwent conventional treatments with invasive MV in three teaching hospitals in Shiraz, Iran, from March 2010 to February 2015. In total, 44 patients (mean age of 27.9 ± 9.98 years) had undergone MV due to PIPI-CRF. None of the patients had a successful wean off from the ventilator. Although all the patients’ were on aggressive life support and full efforts to resuscitate were carried out in case of cardiac arrest, all of them expired. We suggest that in the case of conventional treatment of paraquat poisoning, only noninvasive ventilation should be applied. However, considering the chance of patient’s survival performing novel treatments, such as extracorporeal membrane oxygenation (ECMO), lung protective ventilation with optimal positive end-expiratory pressure (PEEP) could be applied only in such circumstances.

Clinical Features, Treatment, Prognosis, and Mortality in Paraquat Poisonings: A Hospital-Based Study in Iran

Objective:

The aim of the present study was to evaluate the demographics, clinical characteristics, fatal dose, the efficacy of treatments, and prognosis in paraquat (PQ) poisoning in the Kerman Province of Iran.

Methods:

This analytical cross-sectional study was conducted on 126 PQ poisoned patients who were referred to Afzalipour Hospital during 2006–2015. Demographic variables such as age and gender, signs and symptoms of poisoning, the estimated ingested dosage of PQ, and clinical outcome were extracted from medical records. Patients were compared and categorized into two groups considering the outcome: survivors and nonsurvivors. Patients with nonoral exposures, combined drug exposures, PQ exposures more than 24 h before the presentation, and critical underlying diseases were not included in the study.

Findings:

Our results indicated that the mean dose of PQ used by all patients was 2358 mg, which was reported as 1846 and 2812 mg in females and males, respectively. Moreover, the results showed that the highest mortality rate was in patients with respiratory distress, followed by oral ulceration and excess salivation. In all PQ-poisoned patients, the dose of greater than approximately 2250 mg predicted death with 86.2% specificity and 75.7% sensitivity.

Conclusion:

Based on the results of the present study, the mortality rate in PQ-poisoned patients depended on the dose of poison, blood sugar level, and aspartate transaminase levels. Our results suggest that these parameters have excellent prognostic value for the prediction of mortality.

Beclin 1, LC3, and p62 expression in paraquat-induced pulmonary fibrosis

Paraquat (PQ) is a highly toxic herbicide to humans. Pulmonary fibrosis is one of the most typical features of PQ poisoning, which develops from several days to weeks after ingestion. However, the mechanism of fibrosis is still unclear. In this study, we aimed to determine expressions of autophagy-related markers Beclin 1, microtubule-associated protein light chain 3 (LC3), and p62 in PQ-poisoned lungs and to explore the role of autophagy in pulmonary fibrosis induced by PQ. We detected markers of lung fibrosis and expressions of autophagy-related protein in the specimens from eight fatal cases of PQ poisoning by hematoxylin and eosin staining, Masson's trichrome staining, and immunohistochemistry. Based on the staining results of lung fibrosis, these cases were divided into two groups, fibrosis and non-fibrosis groups. The correlation between autophagy protein expressions and pulmonary fibrosis was examined. The results demonstrated that the autophagy-related proteins were significantly expressed in fibrosis group compared with the non-fibrosis group. There was a significantly positive correlation between these protein expressions and severity of lung fibrosis. In conclusion, autophagy dysfunction may be involved in lung fibrogenesis caused by PQ poisoning. This may be a promising clue for understanding the molecular mechanism underlying PQ-induced lung fibrosis and provide evidence for treating fibrosis by regulating the level of autophagy.

Predictive value of the maximum serum creatinine value and growth rate in acute paraquat poisoning patients

This retrospective and a single-center study evaluated the prognostic value of the maximum serum creatinine value (maxCr) and the maximum serum creatinine growth rate (Vmax) after paraquat (PQ) ingestion. One hundred and seventy-one patients with PQ poisoning were treated with a uniform protocol. Demographic variables, clinical manifestations, relevant laboratory data, maxCr and Vmax of all patients were recorded and calculated. The time after PQ ingestion of maxCr and Vmax were also recorded. Vmax and MaxCr exhibited statistically significant differences between the survivor (n = 53) and death (n = 118) groups. Vmax appeared earlier in the death group than the survivor group. Regard to the receiver operating characteristic (ROC) curve analysis, Vmax had an AUC of 0.861 (95% CI, 0.801–0.921) and the optimal cut-off value of 6.21 μmol/(L·h) (sensitivity, 76.3%; specificity, 81.1%). MaxCr had an area under the curve (AUC) of 0.821 (95% CI, 0.752–0.889) and the optimal cut-off value of 225.5 µmol/L (sensitivity, 82.2%; specificity, 67.9%). The comparison of the AUC in the two parameters showed no significant difference, but Vmax appeared earlier than maxCr. Based on binary logistic regression analysis, MaxCr and Vmax both showed strong predictive powers for evaluating the prognosis of acute PQ poisoning patients.

Paraquat initially damages cochlear support cells leading to anoikis-like hair cell death

Paraquat (PQ), one of the most widely used herbicides, is extremely dangerous because it generates the highly toxic superoxide radical. When paraquat was applied to cochlear organotypic cultures, it not only damaged the outer hair cells (OHCs) and inner hair cells (IHCs), but also caused dislocation of the hair cell rows. We hypothesized that the dislocation arose from damage to the support cells (SCs) that anchors hair cells within the epithelium. To test this hypothesis, rat postnatal cochlear cultures were treated with PQ. Shortly after PQ treatment, the rows of OHCs separated from one another and migrated radially away from IHCs suggesting loss of cell-cell adhesion that hold the hair cells in proper alignment. Hair cells dislocation was associated with extensive loss of SCs in the organ of Corti, loss of tympanic border cells (TBCs) beneath the basilar membrane, the early appearance of superoxide staining and caspase-8 labeling in SCs below the OHCs and disintegration of E-cadherin and β-catenin in the organ of Corti. Damage to the TBCs and SCs occurred prior to loss of OHC or IHC loss suggesting a form of detachment-induced apoptosis referred to as anoikis.

Clinical features and prognosis of paraquat poisoning in French Guiana: A review of 62 cases

Paraquat is a nonselective contact herbicide of great toxicological importance, being associated with high mortality rates. Because of its high toxicity, the European Union withdrew it from its market in 2007. The aim of this study is to analyze all cases of paraquat poisoning hospitalized in French Guiana in order to assess their incidence and main characteristics.Medical records of all paraquat intoxicated patients hospitalized from 2008 until 2015 were reviewed in this retrospective study.Demographics, clinical presentation, and laboratory data were evaluated.A total of 62 cases were reviewed. The incidence of paraquat poisoning was 3.8/100,000 inhabitants/year. There were 44 adults and 18 children younger than 16 years of age. The median ages were 31 years [18.08-75.25] in adults and 13.4 years [0.75-15.08] in children, respectively. The median duration of hospitalization was longer in children [15.5 days (1-24)] than in adults [2 days (1-30)], P < .01. The majority of cases was due to self-poisoning (84%).Children had ingested a lower quantity of paraquat [48.8 mg/kg (10-571.1)] than adults [595.8 mg/kg (6-3636.4), P = .03]. There were more deaths among adults (65%) than in children (22%), P = .004. The severity and outcome was determined primarily by the amount of paraquat ingested.In conclusion, French Guiana has the largest cohort of paraquat poisonings in the European Union. The major factor affecting the prognosis of patients was the ingested amount of paraquat. The administration of activated charcoal or Pemba, in situ, within the first hour after ingestion of paraquat is essential.