Acrylamide Neurotoxicity as a Possible Factor Responsible for Inflammation in the Cholinergic Nervous System

Optimization of cellular microenvironment of custom 3D printed brain-mimetic hydrogel and its application in drug neurotoxicity evaluation

In this study, a customized biomimetic brain-mimetic hydrogel model was developed using Digital Light Processing (DLP) 3D printing technology. This model aims to optimize the cellular microenvironment for the growth of neural stem cells and to evaluate the neurotoxicity of various drugs effectively. By precisely controlling the material composition, printing process, and structural design, the pore structure, water absorption, mechanical properties, and formability of the hydrogel were optimized, creating a more biomimetic microenvironment for the survival and proliferation of neural stem cells. Our developed composite hydrogel (GelMA-HAMA-SilMA-Gelatin) achieved a relatively low elastic modulus, excellent water absorption, good biocompatibility, and superior printability by adjusting printing parameters. This makes it better suited to approximate the optimal microenvironment for neural stem cell growth, enhancing cellular proliferation and vitality. Furthermore, our research demonstrated that the 3D hollow brain-mimetic hydrogel model, which features macronutrient channels and microporous networks, significantly improved the survival and proliferation of neural stem cells. Using this model, the neurotoxicity of acrylamide and oxaliplatin was evaluated, confirming the model's effectiveness in evaluating drug neurotoxicity and its ability to demonstrate cellular sensitivity to drug dosages. Compared to conventional two-dimensional adherent cell culture models, our three-dimensional brain-mimetic model can more accurately simulate the complex in vivo environment, offering new perspectives for drug screening and neurotoxicity evaluation. This study not only demonstrates the application potential of 3D printing technology in optimizing cellular microenvironments and drug screening but also emphasizes the importance of considering the cellular microenvironment during drug development. Ultimately, it provides new strategies and tools for evaluating drug safety.

Protective Effect of Sulfur-Containing Heterocyclic Analogs Against Acrylamide-Induced Behavioral and Biochemical Alterations in Zebrafish

Acrylamide (ACR) is a water-soluble monomer with broad consumer applications, even in foods due to thermal processes. Acute exposure to ACR may lead to neurotoxic effects such as ataxia and skeletal muscle weakness in humans and experimental animals. Oxidative stress is the primary pathway in ACR toxicity; therefore, this study aimed to evaluate the possible protective effect of benzo[b]thiophene analogs as an antioxidant drug for ACR poisoning. For this purpose, adult zebrafish were chosen as the experimental model considering the 3Rs of research. Hydroxyl containing benzo[b]thiophene analogs, 1-(3-hydroxybenzo[b]thiophen-2-yl) ethanone (BP) and 1-(3-hydroxybenzo[b]thiophen-2-yl) propan-1-one hydrate (EP) were injected via intraperitoneal (i.p.) route at an effective dose of 5 mg/kg one hour before the exposure of ACR (0.75 mM) for three days. ACR fish showed aberrant socio-behavior with low exploration, tight circling, negative scototaxis, disrupted aggression, and tight shoaling. These results indicated depression comorbid and anxiety-like phenotype. BP and EP partially reduced the aberrant socio-behavior. BP and EP elevated the antioxidant defense and reduced the oxidative damage in the brain caused by ACR. Cellular and tissular alterations caused by ACR were visualized through histopathological study. BP and EP administration reduced and repaired the cellular changes via the antioxidant mechanism. BP and EP altered the axonal growth and regeneration gene and synaptic vesicle cycle gene expression necessary for neurotransmission. This combined gain-of-function of redox mechanism at molecular, cellular, and tissular levels explains the behavioral improvement at the organismal level of the organization.

Complications of Polyacrylamide Hydrogel Facial Injection: Clinical Studies and Literature Review

BACKGROUND

Polyacrylamide hydrogel (PAHG) is a new biomaterial that emerged in the last century and has been widely used in human filler procedures, such as injectable breast augmentation and facial contour improvement. However, as the implantation time of the material increases, various complications have been reported, which reflects that the safety of this material has not been adequately studied. Therefore, a more in-depth experimental analysis becomes particularly important.

METHODS

We collected lesion tissues from six patients with PAHG facial injection. The lesion tissues were examined histologically and molecularly.

RESULTS

Complications caused by PAHG facial injection included pain, subcutaneous nodules, swelling and gel displacement. Western blot revealed decreased expression of neural tissue markers, and increased expression of macrophage markers and oxidative stress-related factors. The results of this study provide new insights into the mechanism and development of PAHG facial injection complications.

CONCLUSION

This report explores the possible mechanism of PAHG complications after facial injection from a new perspective of oxidative stress and inflammation for the first time, which provides a reference for researchers and clinicians to further understand the characteristics of materials and strictly control surgical indications to reduce complications.

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Toxicological landscape of Fuzi: a comprehensive study on the spatial distribution of toxicants and regional neurotoxicity variability in zebrafish

Fuzi, a Chinese herb widely used in clinical settings, exhibits varying levels of toxicity depending on its geographical origin. Diester-type alkaloids are the primary contributors to the toxicity of Fuzi. This study aims to investigate regional differences and underlying mechanisms of Fuzi-induced neurotoxicity across China. Matrix-assisted laser desorption/Ionization mass spectrometry imaging (MALDI-MSI) method was employed to map the spatial distribution of six key diester-type alkaloids from Fuzi samples originating from five major regions. The results showed that the diester-type alkaloids were primarily distributed in the cuticle of Anguo- and Ludian-Fuzi, in the cuticle, cork, and pith of Butuo-Fuzi, in the phloem and pith tissues of Chenggu-Fuzi, and in the cuticle, cork, inner phloem, and pith of Jiangyou-Fuzi. When zebrafish were exposed to a Fuzi decoction for 24 h, it was observed that Jiangyou-Fuzi induced the most significant neurobehavioral abnormalities, lipid peroxidation damage, and aberrant neurotransmitters release. RNA sequencing analysis further indicated that the amino acid metabolism, ErbB, cGMP-PKG, and p53 signaling pathways-regulated by changes in the expression of Glub, Mao, GAB1, PRKG1B, PSEN2, and BAXα genes were disrupted to varying extents by Fuzi from different origins. In summary, the regional variability in the neurotoxicity of Fuzi can be attributed to differences in the distribution of its active compounds and underlying mechanisms. Among the samples tested, Jiangyou-Fuzi exhibited the highest neurotoxicity, followed by Anguo-, Chenggu-, Ludian-, and Butuo-Fuzi.

The effects of microplastics exposure on quail's hypothalamus: Neurotransmission disturbance, cytokine imbalance and ROS/TGF-β/Akt/FoxO3a signaling disruption

Microplastics (MPs) have become a major focus of environmental toxicology, raising concerns about their potential adverse effects on animal organs and body systems. As these tiny particles infiltrate ecosystems, they may pose risks to the health of organisms across diverse species. In this study, we attempted to examine the neurotoxic effects of MPs exposure on avian hypothalamus by using an animal model-Japanese quail (Coturnix japonica). The quails of 7-day-old were exposed to 0.02 mg/kg, 0.4 mg/kg and 8 mg/kg polystyrene microplastic (PS-MPs) of environmental relevance for 35 days. The results showed PS-MPs exposure did damages to hypothalamic structure characterized by neuron malformation, irregular arrangement and cellular vacuolation after 5-week exposure. PS-MPs exposure also induced Nissl body reduction and dissolution in the hypothalamus. Moreover, the decrease of acetylcholinesterase (AchE) activity and increasing acetylcholine (Ach) indicated that PS-MPs exposure caused hypothalamic neurotransmission disturbance. PS-MPs exposure also led to neuroinflammation by disrupting the balance between proinflammatory and anti-inflammatory cytokines. Moreover, increasing reactive oxygen species (ROS) and malondialdehyde (MDA) generation with reducing antioxidants indicated PS-MPs led to hypothalamic oxidative stress. Additionally, RNA-Seq analysis found that both transforming growth factor-β (TGF-β) signaling and forkhead box O (FoxO) signaling were disturbed in the hypothalamus by PS-MPs exposure. Especially, the increasing ROS led to TGF-β activation and then induced hypothalamic inflammation by nuclear factor κB (NF-κB) activation. The present study concluded that oxidative stress might be an important mechanistic signaling involved in MPs neurotoxicology.

Zinc Ameliorates Acrylamide-Induced Cognitive Impairment in Male Wistar Rats: Modulation of Oxidative Stress, Neuro-inflammation, and Neurotrophic Pathways

This study investigated the neuromodulatory potential of zinc against acrylamide-induced cognitive impairment. Acrylamide (AA), a toxic substance commonly found in certain foods such as potato, grains and coffee, is known to cause neurological damage and severe cognitive decline. Twenty (20) male Wistar rats were divided into four groups (n = 5) by random selection. All groups except Control (Group 1) which received 1 mL/kg water daily, were induced with an oral dose of 10 mg/kg of Acrylamide. Acrylamide (AA) (Group 2) was left untreated, while Low Zinc (AA + LZN-Group 3) and High zinc (AA + HZN-Group 4) were orally treated respectively with 10 mg/kg and 30 mg/kg of Zinc for 8 weeks. Zinc treatment mitigated the anxiety-like behavior and spatial and non-spatial memory deficit which are all signs of cognitive impairment observed in the AA group. Zinc reverses the significant decrease in superoxide dismutase (SOD) and catalase, significant increase in malondialdehyde (MDA) and interleukin 1β (IL-1β) caused by AA demonstrating its antioxidant and anti-inflammatory properties. Zinc also demonstrated potency in up-regulating brain-derived neurotrophic factor (BDNF) gene expression and down-regulating acetylcholinesterase (AChE) expression. Zinc treatment at both doses significantly increased the number of dentate gyrus cells. This study demonstrates the ability of zinc to mitigate the cognitive impairment secondary to acrylamide exposure.

Exposure to acrylamide and increased risk of depression mediated by inflammation, oxidative stress, and alkaline phosphatase: Evidence from a nationally representative population-based study

BACKGROUND

The health risk associated with acrylamide exposure has emerged as a significant issue of public health, attracting global attention. However, epidemiologic evidence on whether and how daily acrylamide exposure increases depression risk of the general population is unclear.

METHODS

The study included 3991 adults from the National Health and Nutrition Examination Survey. The urinary metabolites of acrylamide (N-Acetyl-S-(2-carbamoylethyl)-L-cysteine [AAMA] and N-Acetyl-S-(2-carbamoyl-2-hydroxyethyl)-L-cysteine [GAMA]) identified as reliable indicators of acrylamide exposure were examined to determine their relationships with depressive symptoms that were evaluated using the 9-item Patient Health Questionnaire. Besides, the measurements of alkaline phosphatase (ALP) and biomarkers of inflammation (white blood cell [WBC] count) and anti-oxidative stress (albumin [ALB]) were conducted to investigate their mediation roles in above relationships.

RESULT

AAMA, GAMA, and ΣUAAM (AAMA+GAMA) were linearly associated with increased risk of depressive symptoms. Each 2.7-fold increase in AAMA, GAMA, or ΣUAAM was associated with a 30 % (odds ratio: 1.30; 95 % confidence interval: 1.09, 1.55), 47 % (1.47; 1.16, 1.87), or 36 % (1.36; 1.13, 1.63) increment in risk of depressive symptoms, respectively. Increased WBC count (mediated proportion: 4.48-8.00 %), decreased ALB (4.88-7.78 %), and increased ALP (4.93-5.23 %) significantly mediated the associations between acrylamide metabolites and depressive symptoms.

CONCLUSIONS

Acrylamide exposure of the general adult population was related to increased risk of depressive symptoms, which was mediated in part by inflammation, oxidative stress, and increased ALP. Our findings provided pivotal epidemiologic evidence for depression risk increment from exposure to acrylamide.

Zinc ameliorates acrylamide-induced oxidative stress and apoptosis in testicular cells via Nrf2/HO-1/NfkB and Bax/Bcl2 signaling pathway

BACKGROUND

Acrylamide is a toxic substance formed in some foods that require high-temperature cooking processes and has been implicated as a gonadotoxic agent. Zinc, on the other hand, is a known antioxidant with fertility-enhancing properties. Hence, this study was designed to explore the possible ameliorative effect of zinc in acrylamide-induced gonadotoxicity.

METHODS

Twenty-four male Wistar rats were randomized into control, acrylamide (10 mg/kg of acrylamide), acrylamide + 1 mg/kg of zinc, and acrylamide + 3 mg/kg of zinc. The administration was via the oral route and lasted for 56 days.

RESULTS

Zinc treatment ameliorated acrylamide-impaired sperm quality, normal testicular histoarchitecture, and hormonal balance, which was accompanied by increased testicular malondialdehyde and interleukin-1β and decreased testicular superoxide dismutase (SOD) and catalase (CAT). Furthermore, zinc prevented acrylamide-induced downregulation of testicular nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), and B-cell lymphoma 2 (BCl2) expression and upregulation of testicular nuclear factor kappa B (NF-κB) and bcl-2-like protein 4 (bax) expression.

CONCLUSION

In conclusion, zinc may protect against acrylamide-induced testicular toxicity, mediated by its antioxidant, anti-inflammatory, and antiapoptotic effects.

Traditional food processing and Acrylamide formation: A review

Tradition methods that are applied for the processing of food commonly use relatively high temperature and long cooking time for the preparation of foods. This relatively high temperature and long processing time of foods especially in the presence of carbohydrate is highly associated with the formation of acrylamide. Acrylamide is a process contaminant that is highly toxic to humans and remains as a global issue. The occurrence of acrylamide in traditional foods is a major public health problem. Studies that are conducted in different countries indicated that traditionally processed foods are highly linked to the formation of acrylamide. Therefore, understanding the factors influencing acrylamide formation during traditional food processing techniques is crucial for ensuring food safety and minimizing exposure to this harmful chemical compound. Several research reports indicate that proper food processing is the most effective solution to address food safety concerns by identifying foods susceptible to acrylamide formation. This review aims to provide an overview of traditional food processing techniques and their potential contribution to the formation acrylamide and highlight the importance of mitigating its formation in food products. The information obtained in this review may be of great value to future researchers, policymakers, society, and manufacturers.

Metabolomic modelling and neuroprotective effects of carvacrol against acrylamide toxicity in rat's brain and sciatic nerve

The study aimed to investigate the harmful effects of acrylamide (AA), which forms in carbohydrate-rich foods at temperatures above 120°C, on the central and peripheral nervous systems and to evaluate the potential neuroprotective effects of carvacrol (CRV). Male Wistar Albino rats were subjected to AA (40 mg/kg/bw/day) and CRV (50 mg/kg/bw/day) for 15 days. Following the last administration, evaluations revealed disrupted gait, heightened thermal sensitivity and altered paw withdrawal thresholds in AA-exposed rats. Notably, AA reduced glutathione (GSH) and raised malondialdehyde (MDA) levels in both brain and sciatic nerve tissues. AA raised nuclear factor erythroid 2-related factor 2 (Nrf2), caspase 3 and nuclear factor κB (NF-κB) gene expressions while decreasing NR4A2. CRV co-administration mitigated gait abnormalities, elevated GSH levels and lowered MDA levels in both tissues. CRV also modulated gene expression, reducing Nrf2 and NF-κB while increasing NR4A2. Histopathological signs of AA-induced neurodegeneration and elevated glial fibrillary acidic protein levels observed in brain and sciatic nerve tissues were rectified with simultaneous administration of CRV, thereby demonstrating neuroprotective efficacy in both regions. This study is pioneering in demonstrating CRV's neuroprotective potential against AA-induced neurotoxicity in both central and peripheral nervous systems, effectively addressing limitations in the literature. In conclusion, the study revealed AA-induced neurodegeneration in the brain and sciatic nerve, with CRV significantly mitigating this neurotoxicity. This novel research underscores CRV's promise as a neuroprotective agent against AA-induced adverse effects in both the central and peripheral nervous systems.

Effect of Acrylamide and Mycotoxins in SH-SY5Y Cells: A Review

Thermal processes induce the formation of undesired toxic components, such as acrylamide (AA), which has been shown to induce brain toxicity in humans and classified as Group 2A by the International Agency of Research in Cancer (IARC), as well as some mycotoxins. AA and mycotoxins' toxicity is studied in several in vitro models, including the neuroblastoma cell line model SH-SY5Y cells. Both AA and mycotoxins occur together in the same food matrix cereal base (bread, pasta, potatoes, coffee roasting, etc.). Therefore, the goal of this review is to deepen the knowledge about the neurological effects that AA and mycotoxins can induce on the in vitro model SH-SY5Y and its mechanism of action (MoA) focusing on the experimental assays reported in publications of the last 10 years. The analysis of the latest publications shows that most of them are focused on cytotoxicity, apoptosis, and alteration in protein expression, while others are interested in oxidative stress, axonopathy, and the disruption of neurite outgrowth. While both AA and mycotoxins have been studied in SH-SY5Y cells separately, the mixture of them is starting to draw the interest of the scientific community. This highlights a new and interesting field to explore due to the findings reported in several publications that can be compared and the implications in human health that both could cause. In relation to the assays used, the most employed were the MTT, axonopathy, and qPCR assays. The concentration dose range studied was 0.1-10 mM for AA and 2 fM to 200 µM depending on the toxicity and time of exposure for mycotoxins. A healthy and varied diet allows the incorporation of a large family of bioactive compounds that can mitigate the toxic effects associated with contaminants present in food. Although this has been reported in some publications for mycotoxins, there is still a big gap for AA which evidences that more investigations are needed to better explore the risks for human health when exposed to AA and mycotoxins.

High-fat diet exacerbated motor dysfunction via necroptosis and neuroinflammation in acrylamide-induced neurotoxicity in mice

Health risks associated with acrylamide (ACR) or high-fat diet (HFD) exposure alone have been widely concerned in recent years. In a realistic situation, ACR and HFD are generally co-existence, and both are risk factors for the development of neurological diseases. The purpose of the present study was to investigate the combined effects of ACR and HFD on the motor nerve function. As a result, neurobehavioral tests and Nissl staining disclosed that long-term HFD exacerbated motor dysfunction and the damage of spinal cord motor neurons in ACR-exposed mice. Co-exposure of ACR and HFD resulted in morphological changes in neuronal mitochondria of the spinal cord, a significantly reduced mitochondrial subunits NDUFS1, UQCRC2, and MTCO1, released the mitochondrial DNA (mtDNA) into the cytoplasm, and promoted the production of reactive oxygen species (ROS). Combined exposure of HFD and ACR activated the calpain/CDK5/Drp1 axis and caused the mitochondrial excessive division, ultimately increasing MLKL-mediated necroptosis in spinal cord motor neurons. Meanwhile, HFD significantly exacerbated ACR-induced activation of NFkB, NLRP3 inflammasome, and cGAS-STING pathway. Taken together, our findings demonstrated that combined exposure of ACR and HFD aggravated the damage of spinal cord motor neurons via neuroinflammation and necroptosis signaling pathway, pointing to additive effects in mice than the individual stress effects.

Preventive and therapeutic effects of azithromycin on acrylamide-induced neurotoxicity in rats

BACKGROUND

Acrylamide (ACR) can induce neurotoxicity through different pathways, including oxidative stress and apoptosis. Azithromycin is well-known for its antioxidant and anti-apoptotic properties.

OBJECTIVE

To evaluate the potential neuroprotective effect of azithromycin in an in vivo model of ACR-induced neurotoxicity, by investigating its impact on oxidative stress and apoptosis pathways.

METHODS

Male rats were divided into eleven groups at random (n = 6). 1:control (vehicle), 2:ACR (50 mg/kg, 11 days, I.P.), 3-7:ACR+ azithromycin (3.1, 6.25, 12.5, 25, 50 mg/kg, 11 days, I.P.), 8-9:ACR+ azithromycin (3.1, 6.25 mg/kg, from day 3-11), 10: ACR+ vitamin E (200 mg/kg, every other day, I.P.), 11. Azithromycin (50 mg/kg). Following the treatment period, a gait score examination was performed, and malondialdehyde (MDA), glutathione (GSH), Bcl-2-associated X protein (Bax)/B-cell lymphoma 2 (Bcl-2) ratio and caspase-3 levels in the cerebral cortex were measured.

RESULTS

Gait abnormality, a drop in GSH, and an increase in lipid peroxidation, Bax/Bcl-2 ratio, and caspase-3 levels were all significantly triggered by ACR in the cerebral cortex versus the control group. Azithromycin 3.1 and 6.25 mg/kg with ACR and azithromycin 6.25 mg/kg with ACR from day 3-11 ameliorated movement disorders caused by ACR. Azithromycin in all doses and both protocols along with ACR decreased the MDA level. Azithromycin (3.1, 6.25 mg/kg) along with ACR in both protocols increased the level of GSH, reduced the Bax/Bcl-2 ratio and caspase-3 amounts in the brain tissue versus the ACR group.

CONCLUSIONS

Administration of azithromycin had both preventive and therapeutic effects on ACR-induced neurotoxicity through its antioxidant and antiapoptotic properties.

Acrylamide toxicity in aquatic animals and its mitigation approaches: an updated overview

Acrylamide (ACR) is widely applied in various industrial activities, as well as in the water purification process. Furthermore, ACR is synthesized naturally in some starchy grains exposed to high temperatures for an extended time during the cooking process. Because of its widespread industrial usage, ACR might be released into water stream sources. Also, ACR poses a high risk of contaminated surface and ground-water resources due to its high solubility and mobility in water. Furthermore, animal studies have indicated that ACR exposure may cause cancer (in many organs such as lung, prostate, uterus, and pancreas), genetic damage (in both somatic and germ cells), and severe effects on reproduction and development. Recently, numerous studies have shown that ACR has a mild acute cytotoxic impact on aquatic species, particularly during early life stages. Besides, wide-spectrum usage of ACR in many industrial activities presented higher environmental risks as well as major hazards to consumer health. This literature was designed to include all potential and accessible reports on ACR toxicity related with aquatic species. The Preferred Reporting Items for Systematic Reviews were applied to evaluate the risk effects of ACR on aquatic organisms, the ACR sub-lethal concentration in the ecosystem, and the possible protective benefits of various feed additives against ACR toxicity in fish. The major findings are summarized in Tables 2 and 3. The primary aim of this literature was to specify the hazards of ACR toxicity related with fish welfare and possible suggested strategies to reduce its risks.

Two decades of research in dietary acrylamide: What do we know today

After nearly two decades since acrylamide was first raised as a potential safety issue in foods, significant progress has been made in understanding its formation during cooking, how to reduce levels in the most concerned foods, and the possible cancer risk to humans. Despite the huge wealth of knowledge gathered on this topic over the past years, a few new discoveries in occurrence, mitigation, analysis and risk assessment are worthy to note. This short review highlights the salient novelties pertaining to acrylamide, particularly in the areas of formation & analysis, existing and possible future regulations in the European Union, and finally considerations that may lead to possibly revisiting the toxicity of acrylamide and the main metabolite, glycidamide.

Acute acrylamide poisoning with severe symptoms in a short time: a case report

BACKGROUND

Acrylamide poisoning is often reported as chronic poisoning presenting with peripheral neuropathy or carcinogenic action due to long-term exposure to low concentrations. However, there have been few reports of acute poisoning due to oral ingestion of acrylamide, where the symptoms appear a few hours after ingestion. Here, we report a case of acute acrylamide poisoning where a high concentration was ingested in a short time, resulting in a fatal outcome due to the rapid course of events.

CASE PRESENTATION

The patient was an adolescent female who ingested 150 ml (148 g) of acrylamide with suicidal intent. A disorder of consciousness was observed when the emergency medical team arrived 36 min later. An hour later, tracheal intubation and intravenous access were performed at a hospital, and 2 h after that, she was transported to our hospital. After she arrived at the hospital, circulatory dynamics could not be maintained despite vasopressor and colloid osmotic infusion, and hemodialysis could not be introduced. Subsequently, cardiopulmonary arrest occurred, and the patient passed away 7 h after ingestion. In the present case, severe symptoms appeared shortly after acrylamide ingestion, unlike other reported cases. In previous report summarizing animal studies, there was a relationship among the symptoms of acute poisoning, the dose, and onset time. The data from this case were compared to those from previous reports, and we were able to predict the early appearance of severe symptoms based on this comparison.

CONCLUSION

The severity of acute acrylamide poisoning by oral ingestion was primarily dependent on the amount and rate of ingestion.

Protective effect of rutin on spinal motor neuron in rats exposed to acrylamide and the underlying mechanism

The present study aimed to investigate the protective effect of rutin on the injury of spinal motor neuron in rats exposed to acrylamide (ACR) the underlying mechanism. Fifty male Sprague-Dawley rats, aged 7-8 weeks, were randomly divided into control group, ACR group (20 mg/kg), low dose(100 mg/kg), medium dose (200 mg/kg) and high dose(400 mg/kg) rutin groups, ten rats in each group. The rats were given intragastric administration for 21 days. Every week, a neurobehavioral test was conducted. Nissl staining was used to observe the morphological changes in motor neurons in the L4-L6 segment of the spinal cord. Immunohistochemistry was used to identify AChE and ChAT in the rat spinal cord. Western blot was used to identify the expression of AChE, ChAT, P-ERK, ERK, and Nrf2 proteins in the rat spinal cord. The commercial kits were used to detect the presence of SOD, GSH, and LDH in the rat spinal cord. At the start of the second week, the medium and high dosage rutin group's rats' gait scores significantly decreased as compared to those of the ACR group. When rutin dosage was increased, the Nissl staining revealed that Nissl bodies was staining intensified compared to the ACR group. Immunohistochemistry and Western blot analysis revealed that AChE and ChAT expression changed when rutin dose was raised, but P-ERK and Nrf2 expression steadily increased in the spinal cord of rats in the medium and high dose groups compared to the ACR group. In the spinal cord of rats in each dosage group compared to the ACR group, the findings of the oxidative stress indices demonstrated that the expression levels of SOD and GSH rose with the increase of rutin dose, while the expression of LDH reduced with the rise of rutin dose. Rutin has an anti-oxidative impact through up-regulating the expression of P-ERK and Nrf2 proteins in the ERK/Nrf2 pathway, which may be connected to its protective action on motor neurons in the spinal cord of rats exposed to ACR.

Are microplastics contributing to pollution-induced neurotoxicity? A pilot study with wild fish in a real scenario

Pollution-induced neurotoxicity is of high concern. This pilot study investigated the potential relationship between the presence of microplastics (MPs) in the brain of 180 wild fish (Dicentrarchus labrax, Platichthys flesus, Mugil cephalus) from a contaminated estuary and the activity of the acetylcholinesterase (AChE) enzyme. MPs were found in 9 samples (5% of the total), all of them from D. labrax collected in the summer, which represents 45% of the samples of this species collected in that season (20). Seventeen MPs were recovered from brain samples, with sizes ranging from 8 to 96 μm. Polyacrylamide, polyacrylic acid and one biopolymer (zein) were identified by Micro-Raman spectroscopy. Fish with MPs showed lower (p ≤ 0.05) AChE activity than those where MPs were not found. These findings point to the contribution of MPs to the neurotoxicity induced by long-term exposure to pollution, stressing the need of further studies on the topic to increase 'One Health' protection.

Neurotoxicity of acrylamide in adult zebrafish following short-term and long-term exposure: evaluation of behavior alterations, oxidative stress markers, expression of antioxidant genes, and histological examination of the brain and eyes

In the present work, 224 adult female zebrafish (56 fish in each group) were randomly divided into four groups (two control groups and two toxicity groups) as per duration of exposure (7 and 21 days). All fish of the two toxicity groups were exposed to 0.610 mM acrylamide (ACR) concentration for 7 and 21 days. The effects of ACR exposure on behavior, oxidative stress biomarkers, molecular expression of antioxidant genes (sod, cat, and nrf2), and histopathological examination of the brain and eye were examined. Our result shows that ACR exposure for 7 days produced an anxiety-like behavior in zebrafish. Short-term exposure of ACR resulted in alterations of oxidative stress markers (SOD and CAT activity, and the level of GSH and MDA) in the brain and eye of zebrafish. However, the antioxidant defense system of adult female zebrafish could be able to counteract the free radicals generated in long-term ACR exposure as indicated by non-significant difference in oxidative insult following short-term and long-term exposure. ACR exposure downregulated the mRNA expression of the sod, cat, and nrf2 (nuclear factor erythroid 2-related factor 2) genes in the brain and eye without significant difference between the two toxicity groups. Mild histological changes in the dorsal telencephalic area, tectum opticum, medulla, and hypothalamus area of the brain of zebrafish have been observed following short-term and long-term ACR exposure. In the eye, marked histological changes in the retinal pigmented epithelium layer (RPE), structural changes of the photoreceptor layer (PRL) with disorganized layer of rods and cones, and reduction of the relative thickness of the RPE, PRL, outer nuclear layer (ONL), and inner nuclear layer (INL) have been noted following ACR exposure for 21 days as compared to 7 days. ACR produced neurobehavioral aberrations and oxidative stress within 7 days of exposure, while various histological changes in the brain and eyes have been observed following long-term exposure (21 days) to ACR.

Investigating the effect of telmisartan on acrylamide-induced neurotoxicity through in vitro and in vivo methods

Objectives

Acrylamide (ACR) is an environmental contaminant and neurotoxin. Telmisartan is an AT1 blocker that has neuroprotective properties basically through its anti-oxidant effect. The effect of telmisartan on ACR-induced neurotoxicity was investigated in this study.

Materials and Methods

Male Wistar rats were randomly assigned to eight groups (n=6): 1:Control (normal saline), 2:ACR (50 mg/kg, 11 days, IP), 3:ACR+vitamin E (200 mg/kg, every other day, 11 days), 4-6:ACR+telmisartan (0.6, 1.25, and 2.5 mg/kg, 11 days, IP), 7:ACR+telmisartan (0.6 mg/kg, days 3-11), 8:Telmisartan (2.5 mg/kg, 11 days). The behavioral test and blood pressure were assessed after 11 days. Then, the levels of MDA and GSH in brain tissue were measured. The MTT assay was used to evaluate the effect of telmisartan on ACR-induced cytotoxicity.

Results

Exposing PC12 cells to ACR decreased cell viability versus the control group. Pretreating PC12 cells with telmisartan (0.0125, 0.025 µM) enhanced cell viability compared with the ACR group. Compared with control samples, ACR significantly caused motor impairment, elevated MDA, and reduced GSH levels. Locomotor abnormalities were significantly ameliorated by telmisartan (0.6, 1.25 mg/kg, 11 days) and vitamin E versus the ACR group. Receiving telmisartan (0.6, 1.25, and 2.5 mg/kg) and vitamin E along with ACR decreased MDA levels and enhanced GSH content compared with the ACR group. There was no significant difference in animal blood pressure between the groups.

Conclusion

Oxidative stress has a chief role in the neurotoxicity of ACR. Telmisartan (in doses that do not affect blood pressure) ameliorated ACR-induced toxicity by inhibiting oxidative stress.

Special Issue: Cholinergic Control of Inflammation

Inflammation caused by infection, tissue trauma, and disease states such as arthritis and inflammatory bowel disease is perceived by the Central nervous System (CNS) through different routes that, by means of neural reflex circuits, regulate the immune system response [...]

The Mechanism of Acrylamide-Induced Neurotoxicity: Current Status and Future Perspectives

Acrylamide (ACR), a potential neurotoxin, is produced by the Maillard reaction between reducing sugars and free amino acids during food processing. Over the past decade, the neurotoxicity of ACR has caused increasing concern, prompting many related studies. This review summarized the relevant literature published in recent years and discussed the exposure to occupational, environmental, and daily ACR contamination in food. Moreover, ACR metabolism and the potential mechanism of ACR-induced neurotoxicity were discussed, with particular focus on the axonal degeneration of the nervous system, nerve cell apoptosis, oxidative stress, inflammatory response, and gut-brain axis homeostasis. Additionally, the limitations of existing knowledge, as well as new perspectives, were examined, specifically regarding the connection between the neurotoxicity caused by ACR and neurodegenerative diseases, NOD-like receptor protein 3 (NLRP3) inflammasome-related neuroinflammation, and microbiota-gut-brain axis signaling. This review might provide systematic information for developing an alternative pathway approach to assess ACR risk.

Encouraging probiotics for the prevention and treatment of immune-related adverse events in novel immunotherapies against malignant glioma

Among the malignant tumors in the central nervous system (CNS), glioma is the most challenging tumor to the public society, which accounts for the majority of intracranial malignant tumors with impaired brain function. In general, conventional therapies are still unable to provide an effective cure. However, novel immunotherapies have changed the treatment scene giving patients a greater potential to attain long term survival, improved quality of life. Having shown favorable results in solid tumors, those therapies are now at a cancer research hotspot, which could even shrink the growth of glioma cells without causing severe complications. However, it is important to recognize that the therapy may be occasionally associated with noteworthy adverse action called immune-related adverse events (IRAEs) which have emerged as a potential limitation of the therapy. Multiple classes of mediators have been developed to enhance the ability of immune system to target malignant tumors including glioma but may also be associated with the IRAEs. In addition, it is probable that it would take long time after the therapy to exhibit severe immune-related disorders. Gut microbiota could play an integral role in optimal immune development and/or appropriate function for the cancer therapy, which is a vital component of the multidirectional communication between immune system, brain, and gut, also known as gut-brain-immune axis. Here, we show the potential effects of the gut-brain-immune axis based on an "engram theory" for the innovative treatment of IRAEs.