Comparative toxicological evaluation of carvacrol, acetylcarvacrol anda fipronil-based pesticide in human blood cells

Plant-derived chemicals are promising substances to control arthropod pests, although synthetic ones are still the most frequently used. Thus, comparative toxicological studies are needed to determine if natural substances are safe alternatives to replace the use of synthetic chemicals. This study aimed to compare the toxicity of carvacrol (natural origin), acetylcarvacrol (semi-synthetic) and a fipronil-based pesticide (synthetic). We assessed the effects of these chemicals on hemolytic activity, erythrocytes morphology and leucocyte viability using whole blood from human subjects. Additionally, DNA damage was evaluated through comet and DNA fragmentation assays. Fipronil and carvacrol caused hemolysis at concentrations ranging from 0.5 to 2.0%, whereas acetylcarvacrol did not cause hemolysis at 0.5 and 0.75%. Fipronil and carvacrol caused severe alterations in erythrocytes' morphology at 2%, such as ghost erythrocytes, elliptocyte-like shape and rouleau-like shape, presenting only 3.3 and 8.3% normal cells, respectively, at this concentration. However, 73.3% erythrocytes incubated with 2% acetylcarvacrol exhibited normal morphology. Fipronil considerably reduced leucocytes viability, decreasing it to 78% at 2%. Carvacrol and acetylcarvacrol showed no differences in leucocyte viability for 0.5 to 1.0%, but a decrease was observed for 2% carvacrol. The comet assay showed similar DNA damage for fipronil and carvacrol, but it was significantly lower for 1 and 2% acetylcarvacrol. Incubation with genomic DNA showed that only fipronil caused fragmentation of this molecule. Thus, we conclude that carvacrol and fipronil can present similar toxicity at higher concentrations. However, acetylation of carvacrol significantly reduced its toxicity to human blood cells compared with the other chemicals.

The hepato- and neuroprotective effect of gold Casuarina equisetifolia bark nano-extract against Chlorpyrifos-induced toxicity in rats

BACKGROUND

The bark of Casuarina equisetifolia contains several active phytoconstituents that are suitable for the biosynthesis of gold nanoparticles (Au-NPs). These nanoparticles were subsequently evaluated for their effectiveness in reducing the toxicity induced by Chlorpyrifos (CPF) in rats.

RESULTS

Various hematological and biochemical measurements were conducted in this study. In addition, markers of oxidative stress and inflammatory reactions quantified in liver and brain tissues were evaluated. Histopathological examinations were performed on both liver and brain tissues. Furthermore, the native electrophoretic protein and isoenzyme patterns were analyzed, and the relative expression levels of apoptotic genes in these tissues were determined. The hematological and biochemical parameters were found to be severely altered in the group injected with CPF. However, the administration of Au-C. equisetifolia nano-extract normalized these levels in all treated groups. The antioxidant system markers showed a significant decrease (P ≤ 0.05) in conjunction with elevated levels of inflammatory and fibrotic markers in both liver and brain tissues of the CPF-injected group. In comparison, the pre-treated group exhibited a reduction in these markers when treated with the nano-extract, as opposed to the CPF-injected group. Additionally, the nano-extract mitigated the severity of histopathological lesions induced by CPF in both liver and brain tissues, with a higher ameliorative effect observed in the pre-treated group. Electrophoretic assays conducted on liver and brain tissues revealed that the nano-extract prevented the qualitative changes induced by CPF in the pre-treated group. Furthermore, the molecular assay demonstrated a significant increase in the relative expression of apoptotic genes in the CPF-injected rats. Although the nano-extract ameliorated the relative expression of these genes compared to the CPF-injected group, it was unable to restore their values to normal levels.

CONCLUSION

Our results demonstrated that the nano-extract effectively reduced the toxicity induced by CPF in rats at hematological, biochemical, histopathological, physiological, and molecular levels, in the group pre-treated with the nano-extract.

Shotgun Proteomic-Based Approach with a Q-Exactive Hybrid Quadrupole-Orbitrap High-Resolution Mass Spectrometer for Protein Adductomics on a 3D Human Brain Tumor Neurospheroid Culture Model: The Identification of Adduct Formation in Calmodulin-Dependent Protein Kinase-2 and Annexin-A1 Induced by Pesticide Mixture

Pesticides are increasingly used in combinations in crop protection, resulting in enhanced toxicities for various organisms. Although protein adductomics is challenging, it remains a powerful bioanalytical tool to check environmental exposure and characterize xenobiotic adducts as putative toxicity biomarkers with high accuracy, facilitated by recent advances in proteomic methodologies and a mass spectrometry high-throughput technique. The present study aims to predict the potential neurotoxicity effect of imidacloprid and λ-cyhalothrin insecticides on human neural cells. Our protocol consisted first of 3D in vitro developing neurospheroids derived from human brain tumors and then treatment by pesticide mixture. Furthermore, we adopted a bottom-up proteomic-based approach using nanoflow ultraperformance liquid chromatography coupled with a high-resolution mass spectrometer for protein-adduct analysis with prediction of altered sites. Two proteins were selected, namely, calcium-calmodulin-dependent protein kinase-II (CaMK2) and annexin-A1 (ANXA1), as key targets endowed with primordial roles. De novo sequencing revealed several adduct formations in the active site of 82-ANXA1 and 228-CaMK2 as a result of neurotoxicity, predicted by the added mass shifts for the structure of electrophilic precursors. To the best of our knowledge, our study is the first to adopt a proteomic-based approach to investigate in depth pesticide molecular interactions and their potential to adduct proteins which play a crucial role in the neurotoxicity mechanism.

Methylated and ethylated dialkylphosphate metabolites of organophosphate pesticides: DNA damage in bone marrow cells of Balb/c mice

Dialkylphosphates (DAPs), metabolites of organophosphate (OP) pesticides, are widely distributed in the environment and are often used as biomarkers of OP exposure. Recent reports indicate that DAPs may be genotoxic, both in vitro and in vivo. We have examined the genotoxicity of the methylated DAPs dimethyldithiophosphate (DMDTP) and dimethylphosphate (DMTP) and the ethylated DAPs diethyldithiophosphate (DEDTP) and diethylphosphate (DETP), in comparison with their parental compounds, malathion and terbufos, respectively, in bone marrow polychromatic erythrocytes (PCE) of male and female Balb/c mice. We also compared DNA damage (comet assay) induced by DMDTP and dimethyl phosphate (DMP) in human cell lines. Both DMDTP and DMP caused DNA damage in peripheral blood mononuclear cells, HeLa cells, and the hepatic cell lines HepG2 and WRL-68. In the in vivo micronucleus assay, methylated and ethylated DAPs increased micronucleated PCE cells in both male and female mice. Female mice were more susceptible to DNA damage. In comparison to their parental compounds, methylated DAPs, particularly DMTP, were more genotoxic than malathion; DEDTP, DETP, and terbufos were similar in potency. These results suggest that DAPs may contribute to DNA damage associated with OP pesticide exposure.

Lycopene attenuates chlorpyrifos-induced hepatotoxicity in rats via activation of Nrf2/HO-1 axis

Chlorpyrifos (CPF), is an organophosphate pesticide that is widely used for agricultural purposes. However, it has well-documented hepatotoxicity. Lycopene (LCP) is a plant-derived carotenoid with antioxidant and anti-inflammatory activities. The present work was designed to evaluate the potential hepatoprotective actions of LCP against CPF-induced hepatotoxicity in rats. Animals were assigned into five groups namely: Group I (Control), Group II (LCP), Group III (CPF), Group IV (CPF + LCP 5 mg/kg), and Group V (CPF + LCP 10 mg/kg). LCP offered protection as evidenced by inhibiting the rise in serum activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and lactate dehydrogenase (LDH) induced by CPF. This was confirmed histologically as LCP-treated animals showed liver tissues with less proliferation of bile ducts and periductal fibrosis. LCP significantly prevented the rise in hepatic content of malondialdehyde (MDA), depletion of reduced glutathione (GSH), and exhaustion of glutathione-s-transferase (GST) and superoxide dismutase (SOD). Further, LCP significantly prevented hepatocyte death as it ameliorated the increase in Bax and the decrease in Bcl-2 expression induced by CPF in liver tissues as determined immunohistochemically. The observed protective effects of LCP were further confirmed by a significant enhancement in heme oxygenase-1 (HO-1) and NF-E2-related factor 2 (Nrf2) expression. In conclusion, LCP possesses protective effects against CPF-induced hepatotoxicity. These include antioxidation and activation of the Nrf2/HO-1 axis.

Organophosphate pesticide-induced toxicity through DNA damage and DNA repair mechanisms

Organophosphate pesticides (OPs) are widely used in agriculture, healthcare, and other industries due to their ability to kill pests. However, OPs can also have genotoxic effects on humans who are exposed to them. This review summarizes the research on DNA damage caused by OPs, the mechanisms behind this damage, and the resulting cellular effects. Even at low doses, OPs have been shown to damage DNA and cause cellular dysfunction. Common phenomena seen in cells that are exposed to OPs include the formation of DNA adducts and lesions, single-strand and double-strand DNA breaks, and DNA and protein inter and intra-cross-links. The present review will aid in comprehending the extent of genetic damage and the impact on DNA repair pathways caused by acute or chronic exposure to OPs. Additionally, understanding the mechanisms of the effects of OPs will aid in correlating them with various diseases, including cancer, Alzheimer's, and Parkinson's disease. Overall, knowledge of the potential adverse effects of different OPs will help in monitoring the health complications they may cause.

Appraisal of sub-chronic exposure to lambada-cyhalothrin and/or methomyl on the behavior and hepato-renal functioning in Oreochromis niloticus: Supportive role of taurine-supplemented feed

The existing study was designed to inspect the toxicological consequences of two pesticides; lambda-cyhalothrin (LCT) and methomyl (MTM) and their combination on Nile tilapia (Oreochromis niloticus) behaviors, oxidative stress, hepato-renal function indices and microarchitectural alterations. In addition, the efficiency of taurine (TUR) to rescue their toxicity was also considered. Juvenile O. niloticus were assigned into eight groups. The control and TUR groups were fed on a basal diet and TUR-enriched (10 g kg¹) diet, respectively. The other groups were fed on a basal diet, and exposed to LCT (0.079 µg L^-1), MTM (20.39 µg L^-1 and (LCT + MTM). The last three groups were (LCT + TUR), (MTM + TUR), and (LCT + MTM + TUR) and fed on a TUR-enriched diet during exposure to LCT and/or MTM for 60 days. The exposure to LCT and/or MTM resulted in several behavioral alterations and stress via enhanced cortisol and nor-epinephrine levels. A significant elevation of serum 8-hydroxy-2- deoxyguanosine, aspartate and alanine aminotransferases, lactate dehydrogenase, Alkaline phosphatase, urea, creatinine was also observed in these groups. Furthermore, reduced antioxidant enzymes activities, including (catlase, glutathione peroxidase, and superoxide dismutase) with marked histopathological lesions in both liver and kidney tissues were detected. The up-regulated Bax and down-regulated Bcl-2 proteins were expressed in the liver and kidney tissues of LCT and/or MTM -exposed groups. Interestingly, all the observed alterations in behaviors, biochemical indices, and histo-architecture of renal and hepatic tissues were mitigated by TUR supplementation. The findings suggest that feeding O. niloticus dietary TUR may help to reduce the negative effects of LCT and/or MTM, and can also support kidney and liver health in O. niloticus, making it a promising aquaculture feed supplement.

Crocin Protects Malathion-Induced Striatal Biochemical Deficits by Inhibiting Apoptosis and Increasing α-Synuclein in Rats' Striatum

Long-term exposure to organophosphates might result in neurodegenerative diseases, comprising Parkinson's disease. Malathion is an organophosphate pesticide with high neurotoxicity. Oxidative stress, apoptosis, and α-synuclein accumulation are important underlying mechanisms in Parkinson's disease. According to studies, crocin, an active constituent of saffron, has anti-apoptotic, anti-inflammatory, and antioxidant properties. Thus, the effect of crocin on malathion-induced striatal biochemical deficits in rats was investigated in this study. Six groups of male Wistar rats were used: 1. control (normal saline); 2. malathion (100 mg/kg/day, i.p.); 3. crocin (10 mg/kg/day, i.p.) + malathion; 4. levodopa (10 mg/kg/day, i.p.) + malathion; 5. crocin (40 mg/kg/day, i.p.); and 6. polyethylene glycol (PEG) (vehicle of levodopa) groups. The drugs were administered for 28 days. The amounts of Bcl-2, Bax, and caspases 3, 8, and 9 proteins in the striatum were measured by western blotting. Also, the amounts of protein and mRNA level of the α-synuclein in striatum tissue were measured by western blotting and RT-qPCR methods. Malathion induced apoptosis by increasing the amount of Bax/Bcl2 ratio and caspases 3 and 9 proteins in rat striatum tissue. It also increased the protein and mRNA level of α-synuclein in striatal tissue. Co-administration of crocin or levodopa with malathion inhibited the toxic effects of malathion on striatal tissue. Crocin ameliorates the neurotoxic effect of malathion by its anti-apoptotic activity and regulating the expression of proteins involved in Parkinson's disease pathogenesis. As a result, crocin has the potential to be used as a treatment for malathion-induced neurotoxicity.

Association between pesticide usage during pregnancy and neonatal hyperbilirubinemia requiring treatment: the Japan Environment and Children's Study

BACKGROUND

Maternal exposure to pesticides during pregnancy may cause oxidative hemolysis leading to neonatal hyperbilirubinemia. This investigation examined for associations between maternal use of pesticides or repellents during pregnancy and neonatal hyperbilirubinemia requiring phototherapy.

METHODS

We used the dataset from the Japan Environment and Children's Study, a large national birth cohort study registered from January 31, 2011 to March 31, 2014. The fixed data of 61,751 live births were used to evaluate the presence of neonatal hyperbilirubinemia and potential confounding factors. We employed multiple logistic regression analysis to identify correlations between the frequency of maternal pesticide or repellent use during pregnancy and clinically relevant neonatal hyperbilirubinemia.

RESULTS

After controlling for confounding factors, there were significant associations between neonatal hyperbilirubinemia necessitating phototherapy and the frequent use of indoor insecticide spray (OR 1.21, 95% CI 1.05-1.38). For spray- or lotion-type insect repellents, an opposite relationship was observed (more than a few times a week: OR 0.70, 95% CI 0.61-0.81, up to a few times a month: OR 0.84, 95% CI 0.78-0.91).

CONCLUSION

The frequent use of indoor insecticide spray during pregnancy showed an increased risk of neonatal hyperbilirubinemia requiring phototherapy, which was absent for spray- or lotion-type insect repellents.

IMPACT

The frequent use of indoor insecticide spray during pregnancy showed an increased risk of neonatal hyperbilirubinemia requiring phototherapy, which was absent for spray- or lotion-type insect repellents. This is the first study examining the effects of maternal exposure to pesticides or repellents on clinically relevant neonatal hyperbilirubinemia using a dataset from a nationwide birth cohort study. This large-scale Japanese cohort study revealed that the frequent use of indoor insecticide spray during pregnancy may increase the risk of neonatal hyperbilirubinemia requiring treatment.

Immunotoxic role of organophosphates: An unseen risk escalating SARS-CoV-2 pathogenicity

Consistent gathering of immunotoxic substances on earth is a serious global issue affecting people under pathogenic stress. Organophosphates are among such hazardous compounds that are ubiquitous in nature. They fuel oxidative stress to impair antiviral immune response in living entities. Aside, organophosphates promote cytokine burst and pyroptosis in broncho-alveolar chambers leading to severe respiratory ailments. At present, we witness COVID-19 outbreak caused by SARS-CoV-2. Infection triggers cytokine storm coupled with inflammatory manifestations and pulmonary disorders in patients. Since organophosphate-exposure promotes necroinflammation and respiratory troubles hence during current pandemic situation, additional exposure to such chemicals can exacerbate inflammatory outcome and pulmonary maladies in patients, or pre-exposure to organophosphates might turn-out to be a risk factor for compromised immunity. Fortunately, antioxidants alleviate organophosphate-induced immunosuppression and hence under co-exposure circumstances, dietary intake of antioxidants would be beneficial to boost immunity against SARS-CoV-2 infection.

The release of contaminants from steel slags and natural aggregates: Evaluation of toxicity and genotoxicity

Steel slags (SS) are the major waste produced by iron and steel industry. Slags may be reused as recycled materials, instead of natural aggregates (NA), to reduce the final disposal in a landfill and the exploitation of raw materials. However, the reuse of SS may generate a potential release of toxic compounds for the environment and humans. The purpose of this study was to evaluate the toxicity and genotoxicity of SS, in comparison with NA, by using an integrated chemical-biological approach to enable their safe reuse in engineering applications. Leaching solutions from samples were obtained by using short-term leaching tests (CEN EN 12457-2, 2004) usually adopted for the evaluation of waste recovery and final disposal. Chemical analyses of leachates were performed according to the Italian legislation on waste recovery (Ministerial Decree 186/2006). The leaching solutions were assayed by using toxicity test on Daphnia magna. Moreover, mutagenicity/genotoxicity tests on Salmonella typhimurium, Allium cepa, and human leucocytes and fibroblasts were carried out. The releases of pollutants from all samples were within the limits of the Italian legislation for waste recovery. Despite the effects that SS and NA could have on different cells, in terms of toxicity and genotoxicity, globally, SS do not seem to be any more hazardous than NA. This ecotoxicological assessment, never studied before, is important for promoting further studies that may support the decision-making process regarding the use of such types of materials.

Pterocarpus mildbraedii leaf extract ebbs propanil-induced oxidative and apoptotic damage in the liver of rats

Phytochemicals derived from plant sources are well recognized as sources of pharmacologically potent drugs in the treatment of several oxidative stress-related ailments. Dichloromethane/methanol (1:1) leaf extract of Pterocarpus mildbraedii was evaluated for its possible protection against oxidative stress and apoptosis in the liver of male Wistar rats exposed to propanil (PRP). In the experimental design, olive oil served as the vehicle, and rats were grouped into control (2 mL/kg olive oil), PRP (200 mg/kg/day), Pterocarpus mildbraedii extract (200 mg/kg/day), and Pterocarpus mildbraedii extract (200 mg/kg/day)+PRP (200 mg/kg/day), and treated daily, p.o., for seven days. Oxidative stress parameters, B-cell lymphoma 2 (Bcl-2), Bcl 2-associated X protein (Bax), p53, caspases (9/3), and terminal transferase dUTP nick end labeling (TUNEL) assays were observed in all groups. Propanil significantly elevated superoxide dismutase and lipid peroxidation levels, while concomitantly depleting GSH and p53 levels. Further, PRP enhanced the expressions of caspase-9, caspase-3, Bax, and TUNEL-positive cells in the liver of rats. However, these observed alterations were reversed following treatment with Pterocarpus mildbraedii extract. Our studies suggest that Pterocarpus mildbraedii extract protected against PRP toxicity by reducing oxidative stress and attenuating critical endpoints in the intrinsic apoptotic pathway.

Systematic mapping of organophosphate contaminant (OPC) research trends between 1990 and 2018

Since the addition of polybrominated diphenyls and organochlorine pesticides (OCPs) to the world banned list, toxic organophosphate contaminants (OPCs) such as organophosphate flame retardants and organophosphate pesticides have been, respectively, used as substitutes. These chemicals are reported to be more toxic than their halogenated counterparts. It is rare to find a study that focuses on visualising the publication trends of these chemical classes. In this study, we employed a bibliometric model to systematically map research activities between 1990 and 2018 using OPC articles retrieved from the WoS and Scopus databases. A total of 1090 articles were retrieved from the hybrid databases with an article/author and author/article ratio of 0.33 and 3.02, respectively. Articles on OPC studies were positively correlated with the number of years (r² = 0.96; y = 0.23x² - 3.82x + 27.90) suggesting an increase in the number of articles on this subject in future. The USA ranked first in terms of articles (n = 245) and citations (n = 12,922) followed by China and India (203 and 89 articles, respectively). Articles from China and the USA had strong collaboration with other countries. Research priorities and top author keywords included pesticides (n = 112), organophosphate (n = 83) and acetylcholinesterase (n = 60) and were also well represented in keywords-plus. Developed countries had higher outputs compared to developing countries. It was observed that from our thematic literature classifications, human toxicity, ecotoxicological impacts, and environmental monitoring of OPCs were of greater importance to scholars, thus indicating the direction of future research. Futuristic studies need to foster partnership with policymakers, journalists, consultants, farmers, artisans and community workers on OPC research. This will not only enhance scientific communication and community engagement but will also increase the awareness of these pollutants to the general public.

Thyroid disrupting pesticides mancozeb and fipronil in mixture caused oxidative damage and genotoxicity in lymphoid organs of mice

The interference in endocrine signaling in particular of hypothyroid-pituitary-thyroid axis during embryonic/neonatal development increases the risk of long-lasting immune dysfunctioning. Anticipating that, environmentally realistic exposure of established thyroid disrupting pesticides of dithiocarbamate group mancozeb and phenylpyrazole fipronil was given to mice as individual and as mixtures (MIX-I/MIX-II) during the critical initiation phase of the immune response from postnatal day (PND) 31 till PND 60 (maturation phase). The direct exposure effect was assessed at PND 61 and the persistent effect was assessed at PND 91. Pronounced oxidative stress/genotoxicity in lymphoid organs at even low dose mixture exposure of pesticides (MIX-I/ MIX-II) continued to suppress the immune system till adulthood; might be due to the synergistic/additive action. The oxidative stress/genotoxicity effect was prevented on T4 supplementation to inhibit immunotoxicity as T4 is an immune enhancer and antioxidants. Oxidative stress/genotoxicity is suggested as a mechanism of thyroid disruption mediated immune suppression.

Assessment of the cytotoxic and mutagenic potential of dichlorvos (DDVP) using in silico classification model; a health hazard awareness in Nigeria

Dichlorvos (DDVP) has been abused in Nigeria for suicide attempts, topical applications to treat an ectoparasitic infestation, and indiscriminate use on farm produce. Exposure to this compound in subacute concentration can cause toxicity in different tissues by alteration of the cellular antioxidative defence mechanism. This analysis is aimed at the systematic profiling of DDVP to assess its cytotoxic and mutagenic potential for human vulnerability using an in silico classification model. DDVP was grouped into categories of analogue chemical compounds generated from inventories based on structural alerts that measure the biological effects on cell lines and animal models using the quantitative structure-activity relationship (QSAR) model. The cytotoxic and mutagenic potential of DDVP was assessed by analyzing target endpoints like skin sensitization, oral/inhalation toxicity, neurotoxicity and mutagenicity. DDVP shows moderate sensitization potential that can induce skin irritation during prolonged exposure because of the presence of dichlorovenyl side-chain that interacts with cellular proteins and causes degradation. 50% lethal dose (LD₅₀) of DDVP per body weight was determined to be 26.2 mg/kg in a rat model at 95% confidence range for acute oral toxicity, and 14.4 mmol/L was estimated as 50% lethal concentration (LC₅₀) in the atmosphere due to acute inhalation toxicity. DDVP can also inhibit acetylcholinesterase in the nervous system to produce nicotinic and muscarinic symptoms like nausea, vomiting, lacrimation, salivation, bradycardia, and respiratory failure may cause death. The widely used pesticide causes weak DNA methylation which can repress gene transcription on promoter sites. DDVP is volatile so it can cause oral and inhalation toxicity coupled with neurotoxicity during prolonged exposure. Serum cholinesterase blood tests should be encouraged in federal and state hospitals to investigate related health challenges as DDVP is still used in Nigeria.

Organophosphate toxicity: updates of malathion potential toxic effects in mammals and potential treatments

Organophosphorus insecticides toxicity is still considered a major global health problem. Malathion is one of the most commonly used organophosphates nowadays, as being considered to possess relatively low toxicity compared with other organophosphates. However, widespread use may lead to excessive exposure from multiple sources. Mechanisms of MAL toxicity include inhibition of acetylcholinesterase enzyme, change of oxidants/antioxidants balance, DNA damage, and facilitation of apoptotic cell damage. Exposure to malathion has been associated with different toxicities that nearly affect every single organ in our bodies, with CNS toxicity being the most well documented. Malathion toxic effects on liver, kidney, testis, ovaries, lung, pancreas, and blood were also reported. Moreover, malathion was considered as a genotoxic and carcinogenic chemical compound. Evidence exists for adverse effects associated with prenatal and postnatal exposure in both animals and humans. This review summarizes the toxic data available about malathion in mammals and discusses new potential therapeutic modalities, with the aim to highlight the importance of increasing awareness about its potential risk and reevaluation of the allowed daily exposure level.

Outcome of patients with chlorpyrifos intoxication

INTRODUCTION

There is a paucity of literature analyzing outcome of chlorpyrifos intoxication.

METHODS

A total of 40 patients with chlorpyrifos intoxication were seen at Chang Gung Memorial Hospital between 2008 and 2017. Patients were stratified into two subgroups according to their prognosis, as good (n = 12) or poor (n = 28). Good prognosis group were defined as patients who survived without serious complications, and poor prognosis group included patients who died and survived after development of severe complications. Demographic, clinical, laboratory, and mortality data were obtained for analysis.

RESULTS

Patients aged 53.8 ± 16.3 years and most were male (80.0%). All patients (100.0%) developed acute cholinergic crisis such as emesis (45.0%), respiratory failure (42.5%), tachycardia (30.0%), kidney injury (22.5%), and seizure (7.5%). Intermediate syndrome developed in 12.5% of patients, but none had delayed neuropathy (0%). The poor prognosis group suffered higher incidences of respiratory failure (p = 0.011), kidney injury (p = 0.026), and prolonged corrected QT interval (p = 0.000), and they had higher blood urea nitrogen level (p = 0.041), lower Glasgow coma scale score (p = 0.011), and lower monocyte count (p = 0.023) than good prognosis group. All patients were treated with atropine and pralidoxime therapy, but six patients (15.0%) still died of intoxication. In a multivariate logistic regression model, blood urea nitrogen was a significant risk factor for poor prognosis (odds ratio: 1.375, 95% confidence interval: 1.001-1.889, p = 0.049). Nevertheless, no mortality risk factor could be identified.

CONCLUSION

The mortality rate of patients with chlorpyrifos intoxication was 15.0%. Furthermore, acute cholinergic crisis, intermediate syndrome, and delayed neuropathy developed in 100.0%, 12.5%, and 0% of patients, respectively.

Organophosphate insecticide exposure and telomere length in U.S. adults

BACKGROUND

Organophosphate insecticides have been widely used for >30 years, and are reported to be associated with various age-related chronic diseases. While shortening of telomere length has been considered as a marker of cellular aging, only a few small studies have been conducted to examine any difference of telomere length in workers exposed to organophosphates versus controls. Epidemiologic studies of the dose-response associations between environmental organophosphate exposure and telomere length in the general population are few.

OBJECTIVE

This study aimed to evaluate the association between levels of organophosphate insecticide exposure and telomere length in the general population.

METHODS

We analyzed data for 1724 participants aged 20 years or more from the National Health and Nutrition Examination Survey 1999-2002. Organophosphate insecticide exposure was estimated using measures of urinary concentrations for 3,5,6-trichloro-2-pyridinol (TCPY) and six non-specific dialkyl phosphate metabolites, e.g., diethyl thiophosphate (DETP). Multiple linear regression was conducted to assess the association between organophosphate exposure and telomere length.

RESULTS

After controlling for sociodemographic and physical factors and urinary creatinine, participants in the second quartile for urinary TCPY had 0.06 (95% CI: 0.02-0.10) T/S ratio shorter telomere length than those in the lowest quartile. By contrast, participants in the second and third tertiles of urinary DETP had 0.08 (95% CI: 0.02-0.14) and 0.06 (95% CI, 0.01-0.11) T/S ratio longer telomere length than those in the lowest tertile. For other five metabolites, there was no association with telomere length.

CONCLUSIONS

Levels of environmental exposures to certain organophosphate insecticides may be linked to altered telomere length in adults in the general population. Although our findings may need to be replicated, we provide the first evidence that environmental exposure to organophosphates may contribute to the alteration of telomere length, which is potentially related to biological aging and to the development of various chronic diseases.

Association of urinary metabolites of organophosphate and pyrethroid insecticides, and phenoxy herbicides with endometriosis

Endometriosis is a hormone-responsive gynecologic disease, signifying its connotations across a woman's life span. Previous studies suggested that endocrine disrupting chemicals were risk factors for endometriosis. Nevertheless, little is known on exposure to organophosphate, pyrethroid and phenoxy acid pesticides on endometriosis diagnosis. In this study, we determined the concentrations of 11 pesticides, metabolites of organophosphate and pyrethroid insecticides, and phenoxy herbicides, in urine collected from 619 reproductive-age women in Utah and California, using liquid chromatography-tandem mass spectrometry. The association of urinary concentrations of pesticides with an increase in the odds of endometriosis diagnosis was examined in 594 women who underwent laparoscopy/laparotomy (operative cohort: n = 471) or pelvic magnetic resonance imaging (population cohort: n = 123), during 2007-2009. 2-Isopropyl-4-methyl-6-hydroxypyrimidine (IMPY), malathion dicarboxylic acid (MDA), para-nitrophenol (PNP), 3,5,6-trichloro-2-pyridinol (TCPY), 3-phenoxybenzoic acid (3-PBA), and 2,4-dichlorophenoxyacetic acid (2,4-D) were detected in ≥95% of the urine samples analyzed. Urinary concentrations of IMPY, MDA, PNP, 3-PBA and 2,4-D tended to be higher in younger, non-Hispanic black, nulliparous and less affluent women. IMPY was the most dominant compound in urine followed by PNP and TCPY. When women in the 4th quartile of IMPY and the 2nd quartile of TCPY concentrations (μg/g creatinine) were compared with women in the 1st quartile, the odds ratios (ORs) for diagnosis of endometriosis increased significantly in unadjusted models (IMPY OR = 1.89, 95% confidence interval (Cl) = 1.12-3.20; TCPY OR = 1.65, 95% Cl = 1.02-2.69) for the operative (n = 471) and entire data set (n = 594), respectively. Our results suggest that exposure to elevated concentrations of diazinon (the parent compound of IMPY) and chlorpyrifos and chlorpyrifos-methyl (parent compounds of TCPY) may be associated with endometriosis.

Walnut Polyphenol Extract Protects against Malathion- and Chlorpyrifos-Induced Immunotoxicity by Modulating TLRx-NOX-ROS

Malathion (MT) and chlorpyrifos (CPF) are immunotoxic organophosphate pesticides that are used extensively in agriculture worldwide. Dietary polyphenols protect against a variety of toxins. In this study, walnut polyphenol extract (WPE) prevents MT- or CPF-induced toxicity to splenic lymphocytes in vitro. WPE promotes the proliferation of MT-exposed splenocytes, as indicated by increases in the proportions of splenic T-lymphocyte subpopulations (CD3+, CD4+, and CD8+ T cells) and levels of T-cell-related cytokines interleukin (IL)-2, interferon-γ, IL-4, and granzyme B, and decreases the apoptosis-associated proteins Bax and p53. WPE also significantly enhances the proliferation of CPF-exposed splenic B lymphocytes (CD19+ B cells) and levels of the B-cell-related cytokine IL-6, leading to decreases of the apoptosis-associated proteins Bax and p53. These effects are related to reduced production of reactive oxygen species (ROS), as evidenced by normalized hydroxyl radical (•OH), malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), and glutathione (GSH) levels, which are associated with decreased expression of NADPH oxidase 2 (NOX2) and dual oxidase 1 (DUOX1). WPE inhibits the production of ROS and expression of NOX by regulating toll-like receptors 4 and 7 in MT- and CPF-exposed splenic lymphocytes. In conclusion, WPE protects against MT- or CPF-mediated immunotoxicity and inhibits oxidative damage by modulating toll-like receptor (TLR)x-NOX-ROS.

Multivariate response surface methodology assisted modified QuEChERS extraction method for the evaluation of organophosphate pesticides in fruits and vegetables cultivated in Nilgiris, South India

An effective, simple and sensitive analytical method has been developed employing liquid chromatography coupled with tandem mass spectrometry and validated for estimation of five organophosphate pesticides at trace levels in six fruits and twelve vegetables. Plackett-Burman design and central composite design was used to screen and optimize the significant factors in modified QuEChERS (quick, easy, cheap, effective, rugged and safe) extraction method. The method evaluation was done by matrix-matched calibration with linearity ranging from 5 to 500 µg/L with a correlation coefficient more than 0.990. The detection and quantification limit ranged from 0.1 to 1.0 µg/kg and 0.5 to 5 µg/kg, respectively. The mean recoveries were in the range of 76.89-110.30 % with the relative standard deviation less than 13.26% for all pesticides. Further, the method developed was applied to analyze real samples cultivated in the hill areas of Nilgiris, South India.

Quercetin plays protective role in oxidative induced apoptotic events during chronic chlorpyrifos exposure to rats

Chlorpyrifos (CPF), an organophosphate insecticide has a wider application throughout the world to protect agricultural crops and vegetables from insects. Polyphenolic compounds are considered as beneficial against toxicities induced by organophosphates. The present study was conducted to understand the neuroprotective role of quercetin in chlorpyrifos-induced apoptotic events in rats. Twenty-four male Sprague Dawley rats weighing 170 to 200 g were divided into four groups viz: Control, chlorpyrifos treated (13.5 mg/kg body wt. alternate day), quercetin treated (50 mg/kg body wt. every day) and combined chlorpyrifos + quercetin treated. All the treatments were carried out for a total duration of 60 days. Protein carbonyl content and acetylcholinesterase activity were estimated in serum along with cerebrum and cerebellum to ascertain neurotoxicity. Further, for appraisal of neurodegeneration as a consequence of apoptosis, protein expressions of Bcl-2, Bax, cytochrome c, caspase-8, and caspase-9 were assessed. The results showed that protein carbonyl contents were markedly increased in both serum and brain tissues (cerebrum and cerebellum) of chlorpyrifos-treated rats when compared with control group and were appreciably improved upon simultaneous supplementation with quercetin. Further, chlorpyrifos treatment revealed a significant decrease in the enzyme activity of acetylcholinesterase in serum as well as in cerebrum and cerebellum, which however was increased upon concomitant treatment with quercetin. In chlorpyrifos-treated animals, we have observed a significant decrease in the protein expression level of Bcl-2, but a remarkable increase in the expression levels of Bax, cytochrome c, caspase-8, and caspase-9 in both cerebrum and cerebellum. Interestingly, when chlorpyrifos-treated animals were supplemented with quercetin, a significant increase in the expression of Bcl-2 and an appreciable decline in the expression levels of Bax, cytochrome c, caspase-8, and caspase-9 was observed. In conclusion, the present study advocates that quercetin may prove to be a useful candidate in containing the oxidative-induced apoptotic events during chlorpyrifos exposure.

miR-513a-5p targets Bcl-2 to promote dichlorvos induced apoptosis in HK-2 cells

miRNAs are crucially involved in cellular responses to exotic chemical toxins. However, the role of miRNAs in organophosphates induced cytotoxicity is poorly understood. In present study, we investigated the role of miR-513a-5p in dichlorvos induced cytotoxicity in human kidney cell line HK-2. We found that dichlorvos increased intracellular ROS level, upregulated miR-513a-5p expression and induced apoptosis in HK-2 cells. Moreover, overexpression of miR-513a-5p promoted apoptosis of HK-2 cells with or without exposure to dichlorvos while anti-miR-513a-5p partially suppressed dichlorvos induced apoptosis. Luciferase assay showed that miR-513a-5p could directly bind to the 3'-untranslated regions of Bcl-2. Furthermore, miR-513a-5p decreased the level of Bcl-2 and promoted dichlorvos induced apoptosis in HK-2 cells through the Bcl-2/Bax-Caspase-3 pathway. Taken together, our findings indicate that miR-513a-5p promotes dichlorvos induced apoptosis by targeting Bcl-2.

Imidacloprid exposure cause the histopathological changes, activation of TNF-α, iNOS, 8-OHdG biomarkers, and alteration of caspase 3, iNOS, CYP1A, MT1 gene expression levels in common carp (Cyprinus carpio L.)

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IMI toxication was evaluated with three different methods.

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Pathological lesions were observed after IMI exposure in gills, liver and brain.

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IMI exposure induced iNOS, 8-OHdG and TNF-α activation in gills, liver and brain.

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IMI exposure caused upregulation iNOS, caspase 3 and MT1 expressions in brain.

Imidacloprid (IMI) is a neonicotinoid that is widely used for the protection of crops and carnivores from insects and parasites, respectively. It is well known that imidacloprid exposure has a harmful effect on several organisms. However, there is little information about imidacloprid toxicity in aquatic animals, particularly fish. Thus, in the current study, we assessed the histopathological changes; activation of iNOS, 8-OHdG and TNF-α; and expression levels of caspase 3, iNOS, CYP1A and MT1 genes in the common carp exposed to imidacloprid. For this purpose, fish were exposed to either a low dose (140 mg/L) or a high dose (280 mg/L) of imidacloprid for 24 h, 48 h, 72 h and 96 h. After IMI exposure, we detected hyperplasia of secondary lamellar cells and mucous cell hyperplasia in the gills, as well as hydropic degeneration in hepatocytes and necrosis in the liver. Moreover, 8-OHdG, iNOS and TNF-α activation was found particularly in the gills and liver but also moderately in the brain. Transcriptional analysis showed that caspase 3 expression was altered low dose and high doses of IMI for 72 h and 96 h exposure (p < 0.05), iNOS expression was up-regulated with both low and high doses of IMI and in a time-dependent manner (p < 0.05, p < 0.01, p < 0.001), CYP1A expression was not significantly changed regardless of the dose of IMI and exposure time (p > 0.05) except with low and high doses of IMI for 96 h (p < 0.05), and lastly, MT1 gene expression was up-regulated only in the brain with low doses of IMI for 96 h and high doses of IMI for 48 h, 72 h and 96 h exposure (p < 0.05, p < 0.01). Our results indicated that acute IMI exposure moderately induce apoptosis in the brain but caused severe histopathological lesions, inflammation, and oxidative stress in the gills, liver, and brain of the common carp.