Evaluation of the effects of chlorpyrifos combined with lipopolysaccharide stress on neuroinflammation and spatial memory in neonatal rats

Hibiscetin attenuates lipopolysaccharide-evoked memory impairment by inhibiting BDNF/caspase-3/NF-κB pathway in rodents

This study explores the neuroprotective potential of hibiscetin concerning memory deficits induced by lipopolysaccharide (LPS) injection in rats. The aim of this study is to evaluate the effect of hibiscetin against LPS-injected memory deficits in rats. The behavioral paradigms were conducted to access LPS-induced memory deficits. Various biochemical parameters such as acetyl-cholinesterase activity, choline-acetyltransferase, antioxidant (superoxide dismutase, glutathione transferase, catalase), oxidative stress (malonaldehyde), and nitric oxide levels were examined. Furthermore, neuroinflammatory parameters such as tumor necrosis factor-α, interleukin-1β (IL-1β), IL-6, and nuclear factor-kappa B expression and brain-derived neurotrophic factor as well as apoptosis marker i.e., caspase-3 were evaluated. The results demonstrated that the hibiscetin-treated group exhibited significant recovery in LPS-induced memory deficits in rats by using behavioral paradigms, biochemical parameters, antioxidant levels, oxidative stress, neuroinflammatory markers, and apoptosis markers. Recent research suggested that hibiscetin may serve as a promising neuroprotective agent in experimental animals and could offer an alternative in LPS-injected memory deficits in rodent models.

Chlorpyrifos-induced dysregulation of synaptic plasticity in rat hippocampal neurons

Chlorpyrifos (CPF) is a widely used organophosphorus pesticide. Increasing evidence has shown that exposure to CPF in early life might induce neurodevelopmental disorders, but the pathogenesis remains uncertain. Synaptic plasticity plays a crucial role in neurodevelopment. This study aimed to investigate the effect of CPF on synaptic plasticity in hippocampal neurons and establish the cellular mechanism underlying these effects. Using CPF-exposed rat and primary hippocampal neurons model, we analyzed the impact of CPF on the synaptic morphology, the expression level of a presynaptic protein, a postsynaptic protein and ionotropic glutamate receptors (iGluRs), as well as the effects on the Wnt/β-catenin pathway. We found that the synapses were shortened, the spines were decreased, and the expression of synaptophysin (Syp), postsynaptic density-95 (PSD-95), GluN1, GluA1 and Wnt7a, as well as active β-catenin in primary hippocampal neurons was decreased. Our study suggests that CPF exposure induced dysregulation of synaptic plasticity in rat hippocampal neurons, which might provide novel information regarding the mechanism of CPF-induced neurodevelopmental disorders.

3-Indolepropionic acid prevented chlorpyrifos-induced hepatorenal toxicities in rats by improving anti-inflammatory, antioxidant, and pro-apoptotic responses and abating DNA damage

The application of chlorpyrifos (CPF), an organophosphorus pesticide to control insects, is associated with oxidative stress and reduced quality of life in humans and animals. Indole-3-propionic acid (IPA) is a by-product of tryptophan metabolism with high antioxidant capacity and has the potential to curb CPF-mediated toxicities in the hepatorenal system of rats. It is against this background that we explored the subacute exposure of CPF and the effect of IPA in the liver and kidney of thirty rats using five cohort experimental designs (n = 6) consisting of control (corn oil 2 mL/kg body weight), CPF alone (5 mg/kg), IPA alone (50 mg/kg), CPF + IPA₁ (5 mg/kg + 25 mg/kg), and CPF + IPA₂ (5 mg/kg + 50 mg/kg). Subsequently, we evaluated biomarkers of hepatorenal damage, oxidative and nitrosative stress, inflammation, DNA damage, and apoptosis by spectrophotometric and enzyme-linked immunosorbent assay methods. Our results showed that co-treatment with IPA decreased CPF-upregulated serum hepatic transaminases, creatinine, and urea; reversed CPF downregulation of SOD, CAT, GPx, GST, GSH, Trx, TRx-R, and TSH; and abated CPF upregulation of XO, MPO, RONS, and LPO. Co-treatment with IPA decreased CPF-upregulated IL-1β and 8-OHdG levels, caspase-9 and caspase-3 activities, and increased IL-10. In addition, IPA averts CPF-induced histological changes in the liver and kidney of rats. Our results demonstrate that co-dosing CPF-exposed rats with IPA can significantly decrease CPF-induced oxidative stress, pro-inflammatory responses, DNA damage, and subsequent pro-apoptotic responses in rats' liver and kidneys. Therefore, supplementing tryptophan-derived endogenous IPA from exogenous sources may help avert toxicity occasioned by inadvertent exposure to harmful chemicals, including CPF-induced systemic perturbation of liver and kidney function.

Pesticides and aging: Preweaning exposure to Chlorpyrifos induces a general hypomotricity state in late-adult rats

The molecular and behavioral effects of the developmental exposure to low doses of Chlorpyrifos (CPF) have been intensively studied in young (neonates and adolescents), and adult animals. However, no study examined influences of developmental CPF exposure in older adult or geriatric rats. This is relevant as such ages are generally linked to cognitive decline and the onset of specific neurodegenerative disorders, some of them previously associated with CPF exposure in both preclinical and human studies. 1 mg/kg/mL of CPF was orally administered to both male and female Wistar rats from Postnatal day 10 to 15. Animals' spatial memory, learning, compulsivity, motricity, and anxiety were analyzed with Morris Water Maze (15-16 months of age) and the Plus-maze (at 18 months of age). Results showed that postnatal CPF exposure did not alter either spatial memory, compulsive-like behaviors, or anxiety levels in late-adult rats. However, CPF exposed rats were hyposensitive to brief disruptions (Probe stage) following the learning phase and showed a general decrease in locomotor activity in both paradigms. These data are relevant as it is the first time that developmental exposure to CPF has been studied at such a late age, observing important effects in locomotor activity that could be linked to specific pathologies previously associated with CPF effects in people. Future studies should extend these findings to other behaviors and molecular outcomes.

The performance of the alarmin HMGB1 in pediatric diseases: From lab to clinic

INTRODUCTION

The ubiquitously expressed nonhistone nuclear protein high-mobility group box protein 1 (HMGB1) has different functions related to posttranslational modifications and cellular localization. In the nucleus, HMGB1 modulates gene transcription, replication and DNA repair as well as determines chromosomal architecture. When the post-transcriptional modified HMGB1 is released into the extracellular space, it triggers several physiological and pathological responses and initiates innate immunity through interacting with its reciprocal receptors (i.e., TLR4/2 and RAGE). The effect of HMGB1-mediated inflammatory activation on different systems has received increasing attention. HMGB1 is now considered to be an alarmin and participates in multiple inflammation-related diseases. In addition, HMGB1 also affects the occurrence and progression of tumors. However, most studies involving HMGB1 have been focused on adults or mature animals. Due to differences in disease characteristics between children and adults, it is necessary to clarify the role of HMGB1 in pediatric diseases.

METHODS AND RESULTS

Through systematic database retrieval, this review aimed to first elaborate the characteristics of HMGB1 under physiological and pathological conditions and then discuss the clinical significance of HMGB1 in the pediatric diseases according to different systems.

CONCLUSIONS

HMGB1 plays an important role in a variety of pediatric diseases and may be used as a diagnostic biomarker and therapeutic target for new strategies for the prevention and treatment of pediatric diseases.

Analysis of PON1 gene polymorphisms (rs662 and rs854560) and inflammatory markers in organophosphate pesticides exposed cohorts from two distinct populations

BACKGROUND AND OBJECTIVES

Organophosphate (OPs) anticholinesterases are one of the main groups of pesticides used in agriculture. Harmful effects of OPs on health have been attributed primarily for irreversible inhibition of acetylcholinesterase (AChE) at nerve synapse. However, studies have shown that inhibition of AChE alone cannot explain all the maladies encountered in prolonged exposure to OPs. Predisposition to population heterogeneity and irregularities in various biochemicals like paraoxonases and inflammatory biochemicals are the possible affects of OPs long term exposure that may lead to sequels of diseases and are less addressed in literature. The study was aimed to assess the cholinergic enzymes (AChE and BChE), PON1, and inflammatory markers (IL1β, IL6, TNFα, CRP, Apo AI, Apo B) and determine the toxicogenetics association of PON1 gene (rs 662 and rs 85456) to chronically OPs exposed groups from Pakistan and Cameroon.

MATERIALS AND METHODS

AChE, BChE and PON1 were measured by colorimetric method using spectrophotometry. Inflammatory markers were determined by Elisa assay. PCR-restriction fragment length polymorphism (PCR-RFLP) using salting out method was employed for SNP genotyping.

RESULTS

The results revealed the significant (p ≤ 0.05) inhibition of cholinergic enzymes PON 1 was found to be 6.91 ng/mL±1.03 and 2.84 ng/mL±1.40 (mean ± SD) in Pakistan and Cameroon groups respectively. IL6, TNFα, CRP were increased and Apo AI was less while Apo B was increased in OP exposed groups in both population groups. SNPs analysis of PON1 showed significant differences in allelic and genotype frequencies of OPs exposed and non-exposed groups.

CONCLUSIONS

PON1 was noticeably less in Cameroonian than Pakistani, albeit both groups have significant decrease in PON1 actity. In addition, the study concludes that OPs induce low grade inflammation, an aetiology of many diseases. Selected PON1 SNPs analysis showed a significant toxicogenetics association with OPs exposure marker enzymes. The results of this study may help in regulation of usage of OPs anticholinesterases in different populations. The study will further open new avenues in toxicogenetic and exploration of SNPs based strategies on organophosphate intoxication.

Agrochemicals and neurogenesis

Agrochemicals or pesticides are compounds widely used to prevent, destroy or mitigate pests such as insects, rodents, herbs and weeds. However, most of them also act as environmental estrogens, anti-estrogens and/or antiandrogenic chemicals. In addition, both herbicides (such as glyphosate and paraquat) and insecticides (such as pyrethroids, organophosphates, neonicotinoids and rotenone) have been shown to exert significant adverse effects on hippocampal neurogenesis. These effects are particularly important because neurogenesis dysregulation could be associated with cognitive decline and neuropathologies such as Alzheimer's disease. This review focuses on the most commonly used agrochemicals in Argentina and their effects on the hippocampal neurogenesis of mammals. It also discusses the disruption of hormone synthesis and action as a possible mechanism through which these chemical compounds could alter the brain functions. Finally, we propose some lines of research to study the potential endocrine mechanisms involved in the effects of agrochemicals on human health and biodiversity.

Ameliorative Effect of Beta vulgaris Root Extract on Chlorpyrifos-Induced Oxidative Stress, Inflammation and Liver Injury in Rats

Exposure to organophosphorus insecticides causes several health problems to animals and humans. Red beetroot (RBR) is rich in antioxidant ingredients and possesses a promising hepatoprotective activity. This study evaluated the potential of RBR extract to prevent chlorpyrifos (CPF)-induced liver injury, with an emphasis on oxidative stress, inflammation and apoptosis. Rats received 10 mg/kg CPF and were treated with 300 mg/kg RBR extract for 28 days. CPF caused liver injury evidenced by elevated serum levels of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and bilirubin, along with several histological alterations. Hepatic lipid peroxidation (LPO) and nitric oxide (NO) levels, as well as inducible nitric oxide synthase (iNOS) and pro-inflammatory cytokines were increased in CPF-intoxicated rats. RBR prevented CPF-induced histological alterations, and ameliorated liver function, LPO, NO, iNOS and pro-inflammatory cytokines. RBR boosted glutathione and antioxidant enzymes, and increased Nrf2 expression. In addition, RBR diminished Bax and caspase-3, and increased Bcl-2 expression. In conclusion, RBR prevented CPF-induced liver injury via attenuation of oxidative stress, inflammation and apoptosis. RBR enhanced antioxidant defenses, suggesting that it could be used as a potential therapeutic intervention to minimize CPF hepatotoxicity.