Polystyrene microplastics affect learning and memory in mice by inducing oxidative stress and decreasing the level of acetylcholine

The alarming link between environmental microplastics and health hazards with special emphasis on cancer

Microplastic contamination is a burgeoning environmental issue that poses serious threats to animal and human health. Microplastics enter the human body through nasal, dermal, and oral routes to contaminate multiple organs. Studies have advocated the existence of microplastics in human breast milk, sputum, faeces, and blood. Microplastics can find their ways to the sub-cellular moiety via active and passive approaches. At cellular level, microplastics follow clathrin and caveolae-dependent pathways to invade the sub-cellular environment. These environmental contaminants modulate the epigenetic control of gene expression, status of inflammatory mediators, redox homeostasis, cell-cycle proteins, and mimic the endocrine mediators like estrogen and androgen to fuel carcinogenesis. Furthermore, epidemiological studies have suggested potential links between the exposure to microplastics and the onset of chronic diseases. Microplastics trigger uncontrolled cell proliferation and ensuing tissue growth leading to various cancers affecting the lungs, blood, breasts, prostate, and ovaries. Additionally, such contamination can potentially affect sub-cellular signaling and injure multiple organs. In essence, numerous reports have claimed microplastic-induced toxicity and tumorigenesis in human and model animals. Nonetheless, the underlying molecular mechanism is still elusive and warrants further investigations. This review provides a comprehensive analysis of microplastics, covering their sources, chemistry, human exposure routes, toxicity, and carcinogenic potential at the molecular level.

A review on micro- and nanoplastics in humans: Implication for their translocation of barriers and potential health effects

As emerging contaminants, micro- and nanoplastics (MNPs) can absorb and leach various toxic chemicals and ultimately endanger the health of the ecological environment and humans. With extensive research on MNPs, knowledge about MNPs in humans, especially their translocation of barriers and potential health effects, is of utmost importance. In this review, we collected literature published from 2000 to 2023, focusing on MNPs on their occurrence in humans, penetrating characteristics in the placental, blood-brain, and blood-testis barriers, and exposure effects on mammalian health. The characteristics and distributions of MNPs in human samples were analyzed, and the results demonstrated that MNPs were ubiquitous in most human samples, except for kidneys and cerebrospinal fluid. In addition, the phenomenon of MNPs crossing barriers and their underlying mechanisms were discussed. We also summarized the potential factors that may affect the barrier crossing and health effects of MNPs, including characteristics of MNPs, exposure doses, administration routes, exposure durations, co-exposure to other pollutants, and genetic predisposition. Exposure to MNPs may cause cytotoxicity, neurotoxicity, and developmental and reproductive toxicity in mammals. People are encouraged to reduce their exposure to MNPs to prevent these adverse health effects. Finally, we discussed the shortcomings of current research on MNPs in humans, providing a valuable reference for understanding and evaluating the potential health risks from MNP exposure in mammals, including humans.

Size-dependent deleterious effects of nano- and microplastics on sperm motility

INTRODUCTION

Growing concerns regarding the reproductive toxicity associated with daily life exposure to micro-/nano-plastics (abbreviated as MNPs) have become increasingly prevalent. In reality, MNPs exposure involves a heterogeneous mixture of MNPs of different sizes rather than a single size.

METHODS

In this study, an oral exposure mouse model was used to evaluate the effects of MNPs of four size ranges: 25-30 nm, 1-5 µm, 20-27 µm, and 125-150 µm. Adult male C57BL/6 J mice were administered environmentally relevant concentrations of 0.1 mg MNPs/day for 21 days. After that, open field test and computer assisted sperm assessment (CASA) were conducted. Immunohistochemical analyses of organ and cell type localization of MNPs were evaluated. Testicular transcriptome analysis was carried out to understand the molecular mechanisms.

RESULTS

Our result showed that MNPs of different size ranges all impaired sperm motility, with a decrease in progressive sperm motility, linearity and straight-line velocity of sperm movement. Alterations did not manifest in animal locomotion, body weight, or sperm count. Noteworthy effects were most pronounced in the smaller MNPs size ranges (25-30 nm and 1-5 µm). Linear regression analysis substantiated a negative correlation between the size of MNPs and sperm curvilinear activity. Immunohistochemical analysis unveiled the intrusions of 1-5 µm MNPs, but not 20-27 µm and 125-150 µm MNPs, into Leydig cells and testicular macrophages. Further testicular transcriptomic analysis revealed perturbations in pathways related to spermatogenesis, oxidative stress, and inflammation. Particularly within the 1-5 µm MNPs group, a heightened perturbation in pathways linked to spermatogenesis and oxidative stress was observed.

CONCLUSIONS

Our data support the size-dependent impairment of MNPs on sperm functionality, underscoring the pressing need for apprehensions about and interventions against the escalation of environmental micro-/nano-plastics contamination. This urgency is especially pertinent to small-sized MNPs.

Polystyrene nanoplastics exacerbate aflatoxin B1-induced hepatic injuries by modulating the gut-liver axis

Dietary pollution of Aflatoxin B1 (AFB1) poses a great threat to global food safety, which can result in serious hepatic injuries. Following the widespread use of plastic tableware, co-exposure to microplastics and AFB1 has dramatically increased. However, whether microplastics could exert synergistic effects with AFB1 and amplify its hepatotoxicity, and the underlying mechanisms are still unelucidated. Here, mice were orally exposed to 100 nm polystyrene nanoplastics (NPs) and AFB1 to investigate the influences of NPs on AFB1-induced hepatic injuries. We found that exposure to only NPs or AFB1 resulted in colonic inflammation and the impairment of the intestinal barrier, which was exacerbated by combined exposure to NPs and AFB1. Meanwhile, co-exposure to NPs exacerbated AFB1-induced dysbiosis of gut microbiota and remodeling of the fecal metabolome. Moreover, NPs and AFB1 co-exposure exhibited higher levels of systemic inflammatory factors compared to AFB1 exposure. Additionally, NPs co-exposure further exacerbated AFB1-induced hepatic fibrosis and inflammation, which could be associated with the overactivation of the TLR4/MyD88/NF-κB pathway. Notably, Spearman's correlation analysis revealed that the exacerbation of NPs co-exposure was closely associated with microbial dysbiosis. Furthermore, microbiota from NPs-exposed mice (NPsFMT) partly reproduced the exacerbation of NPs on AFB1-induced systemic and hepatic inflammation, but not fibrosis. In summary, our findings indicate that gut microbiota could be involved in the exacerbation of NPs on AFB1-induced hepatic injuries, highlighting the health risks of NPs.

Oral Exposure to Microplastics Affects the Neurochemical Plasticity of Reactive Neurons in the Porcine Jejunum

Plastics are present in almost every aspect of our lives. Polyethylene terephthalate (PET) is commonly used in the food industry. Microparticles can contaminate food and drinks, posing a threat to consumers. The presented study aims to determine the effect of microparticles of PET on the population of neurons positive for selected neurotransmitters in the enteric nervous system of the jejunum and histological structure. An amount of 15 pigs were divided into three groups (control, receiving 0.1 g, and 1 g/day/animal orally). After 28 days, fragments of the jejunum were collected for immunofluorescence and histological examination. The obtained results show that histological changes (injury of the apical parts of the villi, accumulations of cellular debris and mucus, eosinophil infiltration, and hyperaemia) were more pronounced in pigs receiving a higher dose of microparticles. The effect on neuronal nitric oxide synthase-, and substance P-positive neurons, depends on the examined plexus and the dose of microparticles. An increase in the percentage of galanin-positive neurons and a decrease in cocaine and amphetamine-regulated transcript-, vesicular acetylcholine transporter-, and vasoactive intestinal peptide-positive neurons do not show such relationships. The present study shows that microparticles can potentially have neurotoxic and pro-inflammatory effects, but there is a need for further research to determine the mechanism of this process and possible further effects.

Using marine mussels to assess the potential ecotoxicological effects of two different commercial microplastics

Microplastics (MPs) in the aquatic environment pose a serious threat to biota, by being confounded with food. These effects occur in mussels which are filter-feeding organisms. Mussels from the genus Mytilus sp. were used to evaluate the ecotoxicological effects of two MPs, polypropylene (PP) and polyethylene terephthalate (PET), after 4 and 28-days. Measured individual endpoints were condition index and feeding rate; and sub-individual parameters, metabolism of phase I (CYP1A1, CYP1A2 and CYP3A4) and II (glutathione S-transferases - GSTs), and antioxidant defense (catalase - CAT). MPs decreased both condition index (CI) and feeding rate (FR). No alterations occurred in metabolic enzymes, suggesting that these MPs are not metabolized by these pathways. Furthermore, lack of alterations in GSTs and CAT activities suggests the absence of conjugation and oxidative stress. Overall, biochemical markers were not responsive, but non-enzymatic responses showed deleterious effects caused by these MPs, which may be of high ecological importance.

Cytotoxicity of amine-modified polystyrene MPs and NPs on neural stem cells cultured from mouse subventricular zone

Microplastics (MPs) and nanoplastics (NPs) are found in various environments such as aquatic, terrestrial, and aerial areas. Once ingested and inhaled, these tiny plastic debris damaged the digestive and respiratory organ systems in animals. In humans, the possible connection between MPs and various diseases such as lung diseases has been raised. Yet, the impact of MPs on the human nervous system has been unclear. Previous research using animals and cultured cells showed possible neurotoxicity of MPs and NPs. In this study, we used neural stem cells cultured from mouse subventricular zone to examine the effects of polystyrene (PS) NPs and MPs with sizes of 0.1 μm, 1 μm, and 2 μm on the cell proliferation and differentiation. We observed that only positively charged NPs and MPs, but not negatively charged ones, decreased cell viability and proliferation. These amine-modified NPs and MPs decreased both neurogenesis and oligodendrogenesis. Finally, fully differentiated neurons and oligodendrocytes were damaged and removed by the application of NPs and MPs. All these effects varied among different sizes of NPs and MPs, with the greatest effects from 1 μm and the least effects from 2 μm. These results clearly demonstrate the cytotoxicity and neurotoxicity of PS-NPs and MPs.

ROS-dependent degeneration of human neurons induced by environmentally relevant levels of micro- and nanoplastics of diverse shapes and forms

Our study explores the pressing issue of micro- and nanoplastics (MNPs) inhalation and their subsequent penetration into the brain, highlighting a significant environmental health concern. We demonstrate that MNPs can indeed penetrate murine brain, warranting further investigation into their neurotoxic effects in humans. We then proceed to test the impact of MNPs at environmentally relevant concentrations, with focusing on variations in size and shape. Our findings reveal that these MNPs induce oxidative stress, cytotoxicity, and neurodegeneration in human neurons, with cortical neurons being more susceptible than nociceptors. Furthermore, we examine the role of biofilms on MNPs, demonstrating that MNPs can serve as a vehicle for pathogenic biofilms that significantly exacerbate these neurotoxic effects. This sequence of investigations reveals that minimal MNPs accumulation can cause oxidative stress and neurodegeneration in human neurons, significantly risking brain health and highlights the need to understand the neurological consequences of inhaling MNPs. Overall, our developed in vitro testing battery has significance in elucidating the effects of environmental factors and their associated pathological mechanisms in human neurons.

Neurotoxicities induced by micro/nanoplastics: A review focusing on the risks of neurological diseases

Pollution of micro/nano-plastics (MPs/NPs) is ubiquitously prevalent in the environment, leading to an unavoidable exposure of the human body. Despite the protection of the blood-brain barrier, MPs/NPs can be transferred and accumulated in the brain, which subsequently exert negative effects on the brain. Nevertheless, the potential neurodevelopmental and/or neurodegenerative risks of MPs/NPs remain largely unexplored. In this review, we provide a systematic overview of recent studies related to the neurotoxicity of MPs/NPs. It covers the environmental hazards and human exposure pathways, translocation and distribution into the brain, the neurotoxic effects, and the possible mechanisms of environmental MPs/NPs. MPs/NPs are widely found in different environment matrices, including air, water, soil, and human food. Ambient MPs/NPs can enter the human body by ingestion, inhalation and dermal contact, then be transferred into the brain via the blood circulation and nerve pathways. When MPs/NPs are present in the brain, they can initiate a series of molecular or cellular reactions that may harm the blood-brain barrier, cause oxidative stress, trigger inflammatory responses, affect acetylcholinesterase activity, lead to mitochondrial dysfunction, and impair autophagy. This can result in abnormal protein folding, loss of neurons, disruptions in neurotransmitters, and unusual behaviours, ultimately contributing to the initiation and progression of neurodegenerative changes and neurodevelopmental abnormalities. Key challenges and further research directions are also proposed in this review as more studies are needed to focus on the potential neurotoxicity of MPs/NPs under realistic conditions.

Microplastics in water: Occurrence, fate and removal

A global study on tap water samples has found that up to 83% of these contained microplastic fibres. These findings raise concerns about their potential health risks. Ingested microplastic particles have already been associated with harmful effects in animals, which raise concerns about similar outcomes in humans. Microplastics are ubiquitous in the environment, commonly found disposed in landfills and waste sites. Within indoor environments, the common sources are synthetic textiles, plastic bottles, and packaging. From the various point sources, they are globally distributed through air and water and can enter humans through various pathways. The finding of microplastics in fresh snow in the Antarctic highlights just how widely they are dispersed. The behaviour and health risks from microplastic particles are strongly influenced by their physicochemical properties, which is why their surfaces are important. Surface interactions are also important in pollutant transport via adsorption onto the microplastic particles. Our review covers the latest findings in microplastics research including the latest statistics in their abundance, their occurrence and fate in the environment, the methods of reducing microplastics exposure and their removal. We conclude by proposing future research directions into more effective remediation methods including new technologies and sustainable green remediation methods that need to be explored to achieve success in microplastics removal from waters at large scale.

A critical review on male-female reproductive and developmental toxicity induced by micro-plastics and nano-plastics through different signaling pathways

It is widely accepted that humans are constantly exposed to micro-plastics and nano-plastics through various routes, including inhalation of airborne particles, exposure to dust, and consumption of food and water. It is estimated that humans may consume thousand to millions of micro-plastic particles, equating to several milligrams per day. Prolonged exposure to micro-plastics and nano-plastics has been linked to negative effects on different living organisms, including neurotoxicity, gastrointestinal toxicity, nephrotoxicity, and hepatotoxicity, and developmental toxicities. The main purpose of this review is to explore the effect of micro-plastics and nano-plastics on the male and female reproductive system, as well as their offspring, and the associated mechanism implicated in the reproductive and developmental toxicities. Micro-plastics and nano-plastics have been shown to exert negative effects on the reproductive system of both male and female mammals and aquatic animals, including developmental impacts on gonads, gametes, embryo, and their subsequent generation. In addition, micro-plastics and nano-plastics impact the hypothalamic-pituitary axes, leading to oxidative stress, reproductive toxicity, neurotoxicity, cytotoxicity, developmental abnormalities, poor sperm quality, diminishes ovarian ovulation and immune toxicity. This study discusses the so many different signaling pathways associated in the male and female reproductive and developmental toxicity induced by micro-plastics and nano-plastics.

The effects of micro- and nanoplastics on the central nervous system: A new threat to humanity?

Given the widespread production and use of plastics, poor biodegradability, and inadequate recycling, micro/nanoplastics (MNPs) have caused widespread environmental pollution. As a result, humans inevitably ingest MNPs through various pathways. However, there is still no consensus on whether exposure to MNPs has adverse effects on humans. This article aims to provide a comprehensive overview of the knowledge of MNPs and the potential mechanisms of their impact on the central nervous system. Numerous in vivo and in vitro studies have shown that exposure to MNPs may pass through the blood-brain barrier (BBB) and lead to neurotoxicity through impairments in oxidative and inflammatory balance, neurotransmitter alternation, nerve conduction-related key enzymes, and impact through the gut-brain axis. It is worth noting that MNPs may act as carriers and have more severe effects on the body when co-exposed with other substances. MNPs of smaller sizes cause more severe harm. Despite the scarcity of reports directly relevant to humans, this review brings together a growing body of evidence showing that exposure to MNPs disturbs neurons and has even been found to alter the memory and behavior of organisms. This effect may lead to further potential negative influence on the central nervous system and contribute to the development of other diseases such as central nervous system inflammation and Parkinson 's-like neurodegenerative disorders. There is a need further to investigate the threat of MNPs to human health.

Mind over Microplastics: Exploring Microplastic-Induced Gut Disruption and Gut-Brain-Axis Consequences

As environmental plastic waste degrades, it creates an abundance of diverse microplastic particles. Consequently, microplastics contaminate drinking water and many staple food products, meaning the oral ingestion of microplastics is an important exposure route for the human population. Microplastics have long been considered inert, however their ability to promote microbial dysbiosis as well as gut inflammation and dysfunction suggests they are more noxious than first thought. More alarmingly, there is evidence for microplastics permeating from the gut throughout the body, with adverse effects on the immune and nervous systems. Coupled with the now-accepted role of the gut-brain axis in neurodegeneration, these findings support the hypothesis that this ubiquitous environmental pollutant is contributing to the rising incidence of neurodegenerative diseases, like Alzheimer's disease and Parkinson's disease. This comprehensive narrative review explores the consequences of oral microplastic exposure on the gut-brain-axis by considering current evidence for gastrointestinal uptake and disruption, immune activation, translocation throughout the body, and neurological effects. As microplastics are now a permanent feature of the global environment, understanding their effects on the gut, brain, and whole body will facilitate critical further research and inform policy changes aimed at reducing any adverse consequences.

Potential Effects of Environmental and Occupational Exposure to Microplastics: An Overview of Air Contamination

Microplastics (MPs) are now ubiquitous environmental contaminants that lead to unavoidable human exposure; they have received increasing attention in recent years and have become an emerging area of research. The greatest concern is the negative impacts of MPs on marine, fresh-water, and terrestrial ecosystems, as well as human health, to the extent that the World Health Organization (WHO) calls for increased research and standardized methods to assess exposure to MPs. Many countries and international organizations are implementing or proposing legislation in this regard. This review aims to summarize the current state of legislation, indoor and outdoor contamination, and potential human health risk due to exposure to airborne MPs, considering that occupational exposure to MPs is also becoming a growing area of concern. Even though research regarding MPs has continuously increased in the last twenty years, the effects of MPs on human health have been scarcely investigated, and toxicity studies are still limited and not directly comparable, due to the lack of standardized studies in this field.

Aged polystyrene microplastics exacerbate alopecia associated with tight junction injuries and apoptosis via oxidative stress pathway in skin

Microplastics (MPs) are pervasive pollutants in the natural environment and contribute to increased levels of illness in both animals and humans. However, thespecific impacts of MPs on skin damage and alopeciaare not yet well understood. In this study, we have examined the effects of two types of polystyrene MPs (pristine and aged) on skin and hair follicle damage in mice. UV irradiation changed the chemical and physical properties of the aged MPs, including functional groups, surface roughness, and contact angles. In both in vivo and in vitro experiments, skin and cell injuries related to oxidative stress, apoptosis, tight junctions (TJs), alopecia, mitochondrial dysfunction, and other damages were observed. Mechanistically, MPs and aged MPs can induce TJs damage via the oxidative stress pathway and inhibition of antioxidant-related proteins, and this can lead to alopecia. The regulation of cell apoptosis was also observed, and this is involved in the ROS-mediated mitochondrial signaling pathway. Importantly, aged MPs showed exacerbated toxicity, which may be due to their elevated surface irregularities and altered chemical compositions. Collectively, this study suggests a potential therapeutic approach for alopecia and hair follicle damage caused by MPs pollution.

Microplastics induced endoplasmic reticulum stress to format an inflammation and cell death in hepatocytes of carp (Cyprinus carpio)

Microplastics (MPs) are a serious threat to the living environment of aquatic organisms. However, there are fewer studies on the toxicity of microplastics to freshwater organisms. This study aimed to establish a polystyrene microplastics (PS-MPs) model by feeding carp (Cyprinus carpio) PS-MP (1000 ng/L) particles 8 μm in size. HE staining revealed a mass of inflammatory cells infiltrated in the carp hepatopancreas. The activities of alkaline phosphatase (AKP), aspartate transaminase (AST), lactate dehydrogenase (LDH), and alanine transaminase (ALT) were strengthened considerably, suggesting that PS-MPs cause injury to the hepatopancreas of carp. Real-Time polymerase chain reaction and western blotting results indicated increased levels of glucose-regulated protein 78 (GRP78), (PKR)-like ER kinase (PERK), eukaryotic translation initiation Factor 2α (EIF2α) and activating transcription Factor 4 (ATF4) genes and increased levels of inflammatory factors downstream of endoplasmic reticulum stress (ERs) thioredoxin-interacting protein (TXNIP), NOD-like receptor protein 3 (NLRP3), interleukin-18 (IL-18), interleukin-1β (IL-1β), and caspase 1. Increased expression of microtubule-associated protein-2 (LC3II), autophagy-related 5 (ATG5) and autophagy-related 12 (ATG12) genes revealed that PS-MPs promoted autophagy in carp hepatocytes. The enhanced expression of the Caspase 12, Caspase 3, and Bax genes suggested that PS-MPs led to the apoptosis of carp hepatocytes. These results suggest that PS-MPs result in serious injury to the hepatopancreas of carp. The present study of PS-MPs in freshwater fish from the aspect of endoplasmic reticulum stress was conducted to provide references and suggestions for toxicological studies of PS-MPs in freshwater environments.

Polystyrene microplastics induced disturbances in neuronal arborization and dendritic spine density in mice prefrontal cortex

An increasing use of plastics in daily life leads to the accumulation of microplastics (MPs) in the environment, posing a serious threat to the ecosystem, including humans. It has been reported that MPs cause neurotoxicity, but the deleterious effect of polystyrene (PS) MPs on neuronal cytoarchitectural morphology in the prefrontal cortex (PFC) region of mice brain remains to be established. In the present study, Swiss albino male mice were orally exposed to 0.1, 1, and 10 ppm PS-MPs for 28 days. After exposure, we found a significant accumulation of PS-MPs with a decreased number of Nissl bodies in the PFC region of the entire treated group compared to the control. Morphometric analysis in the PFC neurons using Golgi-Cox staining accompanied by Sholl analysis showed a significant reduction in basal dendritic length, dendritic intersections, nodes, and number of intersections at seventh branch order in PFC neurons of 1 ppm treated PS-MPs. In neurons of 0.1 ppm treated mice, we found only decrease in the number of intersections at the seventh branch order. While 10 ppm treated neurons decreased in basal dendritic length, dendritic intersections, followed by the number of intersections at the third and seventh branch order were observed. As well, spine density on the apical secondary branches along with mRNA level of BDNF was significantly reduced in all the PS-MPs treated PFC neurons, mainly at 1 ppm versus control. These results suggest that PS-MPs exposure affects overall basal neuronal arborization, with the highest levels at 1 and 10 ppm, followed by 0.1 ppm treated neurons, which may be related to the down-regulation of BDNF expression in PFC.

Oxidized/unmodified-polyethylene microplastics neurotoxicity in mice: Perspective from microbiota-gut-brain axis

Microplastics (MPs) are inevitably oxidized in the environment, and their potential toxicity to organisms has attracted wide attention. However, the neurotoxicity and mechanism of oxidized polyethylene (Ox-PE) MPs to organisms remain unclear. Herein, we prepared oxidized low-density polyethylene (Ox-LDPE) and established a model of MPs exposure by continuously orally gavage of C57BL/6 J mice with LDPE-MPs/Ox-LDPE-MPs for 28 days with or without oral administration of Lactobacillus plantarum DP189 and galactooligosaccharides (DP189&GOS). The experimental results indicated that LDPE-MPs or Ox-LDPE-MPs caused several adverse effects in mice, mainly manifested by behavioral changes, disruption of the intestinal and blood-brain barrier (BBB), and simultaneous oxidative stress, inflammatory reactions, and pathological damage in the brain and intestines. Brain transcriptomic analysis revealed that the cholinergic synaptic signaling pathways, which affect cognitive function, were significantly disrupted after exposure to LDPE-MPs or Ox-LDPE-MPs. Real-time quantitative polymerase chain reaction and Western Blotting results further demonstrated that the critical genes (Slc5a7, Chat and Slc18a3) and proteins (Chat and Slc18a3) in the cholinergic synaptic signaling pathway were significantly down-regulated after exposure to LDPE-MPs or Ox-LDPE-MPs. These alterations lead to reduced acetylcholine concentration, which causes cognitive dysfunction in mice. Importantly, the DP189&GOS interventions effectively mitigated the MPs-induced cognitive dysfunction and intestinal microbiota alteration, improved intestinal and BBB integrity, attenuated the oxidative stress and inflammatory response, and also saw a rebound in the release of acetylcholine. These results indicated that LDPE-MPs and Ox-LDPE-MPs exert neurotoxic effects on mice by inducing oxidative stress, inflammatory responses, and dysregulation of cholinergic signaling pathways in the mouse brain. That probiotic supplementation is effective in attenuating MPs-induced neurotoxicity in mice. Overall, this study reveals the potential mechanisms of neurotoxicity of LDPE-MPs and Ox-LDPE-MPs on mice and their improvement measures, necessary to assess the potential risks of plastic contaminants to human health.

Polystyrene Nano- and Microplastic Particles Induce an Inflammatory Gene Expression Profile in Rat Neural Stem Cell-Derived Astrocytes In Vitro

Microplastics are considered an emerging environmental pollutant due to their ubiquitous presence in the environment. However, the potential impact of microplastics on human health warrants further research. Recent studies have reported neurobehavioral and neurotoxic effects in marine and rodent models; however, their impact on the underlying cellular physiology in mammals remains unclear. Herein, we exposed neural stem cells and neural stem cell-derived astrocytes, oligodendrocytes, and neurons to various sizes and concentrations of polystyrene nano- and microplastics. We investigated their cellular uptake, impact on cytotoxicity, and alteration of gene expression through transcriptome profiling. The cell type most affected by decreased viability were astrocytes after 7 days of repeated exposure. Transcriptional analysis showed that 1274 genes were differentially expressed in astrocytes exposed to 500 nm microplastics, but only 531 genes were altered in astrocytes exposed to 50 nm nanoplastics. Both canonical pathway and Kyoto Encyclopedia of Genes and Genomes analysis showed that upregulated pathways were involved in neuroinflammation, innate and adaptive immunity, cell migration, proliferation, extracellular matrix remodeling, and cytoskeleton structures. The downregulated pathways were involved in lipid metabolism, specifically fatty acid oxidation and cholesterol metabolism. Our results show that neural stem cell-derived astrocytes repeatedly exposed to nano- and microplastics for 7 days undergo changes that are hallmarks of astrogliosis.

Cerebral neurotoxicity of amino-modified polystyrene nanoplastics in mice and the protective effects of functional food Camellia pollen

Accumulating evidence suggests that nanoplastics contribute to an increased risk of brain damage, however, the precise underlying mechanisms remain unclear. Here, we subjected mice to long-term exposure to amino-modified polystyrene nanoplastics (APS-NPs). These nanoplastics were detected in the mouse brain; coupled with the observed upregulation of Alzheimer's disease-associated genes (APP and MAPT). To further explore nanoplastic damage mechanisms and the corresponding protective strategies against these mechanisms in vitro, we used hCMEC/D3 and HT22 cells. Results showed that APS-NPs disrupted tight junction proteins (Occludin and ZO-1) via TLR2/MMP9 axis, resulting in blood-brain barrier permeation; this was significantly mitigated by functional food Camellia pollen treatment. APS-NPs initiated iNOS and nNOS upregulation within neurons resulting in Sirtuin 1 deacetylase inactivation and CBP acetyltransferase stimulation, ultimately leading to Ac-Tau formation. This process was attenuated by Camellia pollen, which also ameliorated the APS-NPs-induced neuronal apoptosis mediated by the p53/Bax/Bcl-2 axis. Network pharmacology analysis of Camellia pollen offered a further theoretical understanding of its potential applications in preventing and treating nervous system disorders, such as Alzheimer's disease. This study established that Camellia pollen protects the brain against APS-NPs-mediated blood-brain barrier damage and alleviates neuronal apoptosis and Alzheimer's disease-like neurotoxicity. This study elucidates the mechanisms underlying polystyrene-induced brain damage and can be used to inform future prevention and treatment strategies.

The potential toxicity of microplastics on human health

Microplastics are plastic particles, films, and fibers with a diameter of < 5 mm. Given their long-standing existence in the environment and terrible increase in annual emissions, concerns were raised about the potential health risk of microplastics on human beings. In particular, the increased consumption of masks during the COVID-19 pandemic has dramatically increased human contact with microplastics. To date, the emergence of microplastics in the human body, such as feces, blood, placenta, lower airway, and lungs, has been reported. Related toxicological investigations of microplastics were gradually increased. To comprehensively illuminate the interplay of microplastic exposure and human health, we systematically reviewed the updated toxicological data of microplastics and summarized their mode of action, adverse effects, and toxic mechanisms. The emerging critical issues in the current toxicological investigations were proposed and discussed. Our work would facilitate a better understanding of MPs-induced health hazards for toxicological evaluation and provide helpful information for regulatory decisions.

Pharmacotherapeutic potential of ginkgetin against polystyrene microplastics-instigated testicular toxicity in rats: A biochemical, spermatological, and histopathological assessment

Polystyrene microplastics (PSMPs) have emerged as a ubiquitous environmental toxicant that affects different organs including testes. Ginkgetin (GNG) is a biflavonoid that shows antioxidant properties. The current research was undertaken to evaluate the ameliorative potential of GNG against PSMPs-instigated testicular damages. Forty-eight albino rats (male) were randomly divided into 4 equal groups: control, PSMPs-treated group (0.01 mgkg-1), GNG + PSMPs-exposed group (25 mgkg-1 + 0.01 mgkg-1), and only GNG-supplemented group (25 mgkg-1). After 56 days of treatment, it was revealed that PSMPs significantly reduced the activity of glutathione peroxidase (GPx), catalase (CAT), superoxide dismutase (SOD), and glutathione reductase (GSR), while concurrently augmented the levels of lipid peroxidation marker, i.e., malondialdehyde (MDA) along with reactive oxygen species (ROS). Rats administered with PSMPs showed a significant reduction in the spermatogenic indices (sperm count, viability, and motility), HOS coiled tail sperm along with increased sperm structural deformities, i.e., tail, head, and mid-piece. Additionally, PSMPs exposure decreased the levels of testosterone, luteinizing (LH), and follicle-stimulating hormones (FSH). Besides, administration of PSMPs reduced the steroidogenic enzymes (13β-HSD, StAR, and 17β-HSD) and Bcl-2 expression, while augmented the caspase-3 and Bax expression. PSMPs also elevated the levels of inflammatory markers (IL-6, IL-1β, TNF-α, and NF-κB) and activity of COX-2 in the testes. Furthermore, PSMPs treatment induced various histopathological damages in the testes of rats. Therefore, findings of the current study suggested that GNG effectively mitigated the PSMPs-induced testicular toxicity owing to its chemoprotective potential possibly through its anti-inflammatory, antioxidant, anti-apoptotic, and androgenic properties.

Microplastics exposure induced and exacerbated the development of systemic lupus erythematosus in mice

Environmental exposure may function as a contributing risk factor in the development of systemic lupus erythematosus (SLE). Recently, the global issue of microplastics (MPs) pollution has garnered increasing concern, yet its potential impact on SLE remains unexplored. This study seeks to elucidate the ramifications of MPs exposure on lupus manifestations in spontaneous lupus MRL/lpr mice and normal C57L/6 mice. MPs exposure demonstrated the capacity to induce lupus-like symptoms in C57BL/6 mice and exacerbate lupus symptoms in MRL/lpr mice. This was manifested by MPs triggering abnormal elevation of spleen DN T, plasma cells, serum anti-dsDNA, ANA, IL-6, and TNF-α, coupled with a reduction in spleen CD4+/CD8+ cell ratio, and impairment in renal pathology. Moreover, a 4D-DIA quantitative proteomic analysis was employed to unveil substantial alterations in renal proteins attributed to MPs exposure. The findings indicated that the KEGG pathways significantly enriched by MPs-associated different proteins in C57BL/6 mice were closely aligned with the enriched KEGG pathways associated with lupus. Unlike C57BL/6 mice, there were no significantly enriched KEGG pathways identified among the MPs-associated different proteins in MRL/lpr mice. In addition, proteins related to the SLE pathway illuminated that MPs exposure induced renal damage through activation of MHCII and histone H3, culminating in the production of MAC in both C57BL/6 and MRL/lpr mice. However, a specific elevation in cathepsin and elastase caused by MPs was observed in C57BL/6 mice but not in MRL/lpr mice. This study represents a significant stride in bridging the existing knowledge gap pertaining to the intricate relationship between MPs exposure and the development of SLE.

Voluntary exercise during puberty promotes spatial memory and hippocampal DG/CA3 synaptic transmission in mice

Physical exercise has been shown to have an impact on memory and hippocampal function across different age groups. Nevertheless, the influence and mechanisms underlying how voluntary exercise during puberty affects memory are still inadequately comprehended. This research aims to examine the impacts of self-initiated physical activity throughout adolescence on spatial memory. Developing mice were exposed to a 4-wk voluntary wheel running exercise protocol, commencing at the age of 30 d. After engaging in voluntary wheel running exercise during development, there was an enhancement in spatial memory. Moreover, hippocampal dentate gyrus and CA3 neurons rather than CA1 neurons exhibited an increase in the miniature excitatory postsynaptic currents and miniature inhibitory postsynaptic currents. In addition, there was an increase in the expression of NR2A/NR2B subunits of N-methyl-D-aspartate receptors and α1GABAA subunit of gamma-aminobutyric acid type A receptors, as well as dendritic spine density, specifically within dentate gyrus and CA3 regions rather than CA1 region. The findings suggest that voluntary exercise during development can enhance spatial memory in mice by increasing synapse numbers and improving synaptic transmission in hippocampal dentate gyrus and CA3 regions, but not in CA1 region. This study sheds light on the neural mechanisms underlying how early-life exercise improves cognitive function.

The enhancement in toxic potency of oxidized functionalized polyethylene-microplastics in mice gut and Caco-2 cells

Microplastics (MPs) are inevitably oxidized in the environment, however, to date, no studies have discussed the biological toxicity of oxidized polyethylene (Ox-PE) MPs. In this study, oxidized low-density polyethylene (Ox-LDPE), a representative Ox-PE, was prepared using a selective oxidation method. The difference in toxicity between LDPE-MPs and Ox-LDPE-MPs were evaluated in C57BL/6 mice and Caco-2 cells. The proton nuclear magnetic resonance (1H NMR) and Fourier transform infrared (FTIR) spectroscopy analyses revealed that some hydrocarbon-containing groups were transformed into carboxyl and ketone groups during selective oxidation. In vivo experiment results showed that LDPE-MPs and Ox-LDPE-MPs exists in the intestinal (duodenum and colon) of mice, and Ox-LDPE-MPs caused more severe intestinal histological changes, oxidative stress, and inflammatory response. The gut microbiota data showed that the relative abundance of Lactobacillus decreased significantly in the LDPE-MP- and Ox-LDPE-MP-exposed groups (P < 0.05). The predicted Kyoto Encyclopedia of Genes and Genomes (KEGG) metabolic pathway suggested that exposure to LDPE-MPs or Ox-LDPE-MPs inhibited glycan biosynthesis and metabolism in the flora (P < 0.05). In vitro experiment results showed that selective oxidation to LDPE promoted its uptake by cells and aggravated adverse effects on cells, including reduced cell viability, damaged cell membrane, oxidative stress, and mitochondrial depolarization. The major mechanism of the increased toxicity of Ox-LDPE-MPs may be its easier accumulation and the ionic effect of oxygen-containing functional groups. Overall, these findings provide insights on the differences in toxicity between LDPE-MPs and Ox-LDPE-MPs. They also provide new perspectives for understanding the biohazards of MPs, which are necessary to accurately assess the potential environmental and health risks of these plastic pollutants.

A systematic review of the impacts of exposure to micro- and nano-plastics on human tissue accumulation and health

Micro- and nano-plastics (MNPs) pollution has become a pressing global environmental issue, with growing concerns regarding its impact on human health. However, evidence on the effects of MNPs on human health remains limited. This paper reviews the three routes of human exposure to MNPs, which include ingestion, inhalation, and dermal contact. It further discusses the potential routes of translocation of MNPs in human lungs, intestines, and skin, analyses the potential impact of MNPs on the homeostasis of human organ systems, and provides an outlook on future research priorities for MNPs in human health. There is growing evidence that MNPs are present in human tissues or fluids. Lab studies, including in vivo animal models and in vitro human-derived cell cultures, revealed that MNPs exposure could negatively affect human health. MNPs exposure could cause oxidative stress, cytotoxicity, disruption of internal barriers like the intestinal, the air-blood and the placental barrier, tissue damage, as well as immune homeostasis imbalance, endocrine disruption, and reproductive and developmental toxicity. Limitedly available epidemiological studies suggest that disorders like lung nodules, asthma, and blood thrombus might be caused or exacerbated by MNPs exposure. However, direct evidence for the effects of MNPs on human health is still scarce, and future research in this area is needed to provide quantitative support for assessing the risk of MNPs to human health.

Attenuative effects of tamarixetin against polystyrene microplastics-induced hepatotoxicity in rats by regulation of Nrf-2/Keap-1 pathway

Polystyrene microplastics (PS-MPs) are environmental contaminants due to their potential to induce damages in multiple organs specifically liver. Tamarixetin (TMT) is a naturally occurring flavonoid present in Tamarix ramosissima plant that exhibits multiple pharmacological properties. Therefore, the present research was designed to evaluate the palliative role of TMT against PS-MPs instigated liver dysfunction in rats. The exposure to PS-MPs reduced the expressions of nuclear factor erythroid 2-related factor 2 and antioxidant genes, while increasing the expression of Kelch-like ECH-associated protein 1. PS-MPs exposed rats exhibited considerably (p < .05) higher alkaline phosphatase (ALP), aspartate aminotransferase (AST) as well as alanine aminotransferase (ALT) contents. Additionally, PS-MPs treatment resulted in a notable decrease in anti-oxidants activity, that is, glutathione S-transferase (GST), superoxide dismutase (SOD), heme oxygenase-1 (HO-1), glutathione reductase (GSR), glutathione peroxidase (GPx), catalase (CAT) and glutathione (GSH) content, whereas upregulating reactive oxygen species (ROS) and malondialdehyde (MDA) contents. Moreover, PS-MPs intoxication noticeably increased (p < .05) the inflammatory indices (interleukin-1ß [IL-1ß], nuclear factor kappa B [NF-κB], interleukin-6 [IL-6], tumor necrosis factor-α [TNF-α] levels, and cyclooxygenase-2 [COX-2] activity). Besides, Caspase-3 and Bax expressions were upregulated and Bcl-2 expression was decreased after PS-MPs exposure. Additionally, the histomorphological examination revealed notable hepatic damage in PS-MPs treated group. However, TMT treatment substantially (p < .05) recovered all the PS-MPs-induced damages and histopathological changes. Taken together, it can be deduced that TMT might be used as a pharmacological agent to ameliorate hepatic damage.

Nano polystyrene induced changes in anxiety and learning behaviour are mediated through oxidative stress and gene disturbance in mouse brain regions

It is widely reported now that nanoplastic particles have potential neurotoxic effects and may disturb central nervous system (CNS) function. However, the mechanism behind these toxic effects still needs to be elucidated. In the current study, we investigated the effects of polystyrene nanoplastics (PS-NPs) on changes in learning, memory, and anxiety-related behavior in mice based on some selected biochemical, molecular, and histopathological changes in three important brain regions (Cortex, Hypothalamus, and Hippocampus). Male mice were orally administered daily with two doses of 50 nm PS-NPs (0.2 mg/ml and 1 mg/ml) for 8 weeks. We observed decreased expression of neurotransmitter-related genes (VAChT, GAD, and SYP) in the cortex, hypothalamus, and hippocampus areas of the mouse brain. Other biochemical variables including, antioxidant enzymes, biomarkers for oxidative stress, and acetylcholinesterase activity showed significant alterations in all three brain regions. Molecular and neurochemical data thus suggest significant neurobehavioral changes following sub-chronic exposure to PS-NPs which may lead to enhanced anxiety-related and spatial learning and memory-related impairments by affecting limbic areas of the brain.

Photoaged microplastics induce neurotoxicity associated with damage to serotonergic, glutamatergic, dopaminergic, and GABAergic neuronal systems in Caenorhabditis elegans

Microplastics (MPs) are ubiquitous environmental contaminants that cause neurotoxicity in various organisms. MPs are typically affected by light irradiation and undergo photoaging. However, the neurotoxic effects of photoaged polystyrene (P-PS) and its underlying mechanisms remain unclear. In this study, locomotion behaviors, neuronal development, neurotransmitter levels, and the expression of neurotransmission-related genes were investigated in Caenorhabditis elegans exposed to P-PS at environment-relevant concentrations (0.1-100 μg/L). The characterization results showed that photoaging accelerated the aging process and changed the physicochemical properties of the MPs. The toxicity results suggested that exposure to 1-100 μg/L P-PS caused more severe neurotoxicity than virgin polystyrene (V-PS) with endpoints of head thrashes, body bends, wavelength, and mean amplitude. Exposure to P-PS also altered the fluorescence intensity and neurodegeneration percentage of serotonergic, glutamatergic, dopaminergic, and aminobutyric acid (GABA) in transgenic nematodes. Similarly, significant reductions in the levels of these neurotransmitters were also observed. Based on Pearson's correlation, locomotion behaviors were negatively correlated with the neurotransmission of serotonin, glutamate, dopamine, and GABA. Further investigation suggested that the expression of neurotransmitter-related genes (e.g., tph-1, eat-4, and unc-46) was significantly altered in the nematodes. Collectively, the neurotoxic effects of P-PS were attributed to abnormal neurotransmission. This study highlights the potential toxicity of MPs photoaged under environmentally relevant conditions.

Assessing micro and nanoplastics toxicity using rodent models: Investigating potential mitochondrial implications

Mitochondria's role as a central hub in cellular metabolism and signaling cascades is well established in the scientific community, being a classic marker of organisms' response to toxicant exposure. Nonetheless, little is known concerning the effects of emerging contaminants, such as microplastics, on mitochondrial metabolism. Micro- and nanoplastics present one of the major problems faced by modern societies. What was once an environmental problem is now recognized as an one-health issue, but little is known concerning microplastic impact on human health. Indeed, only recently, human exposure to microplastics was acknowledged by the World Health Organization, resulting in a growing interest in this research topic. Nonetheless, the mechanisms behind micro- and nanoplastics toxicity are yet to be understood. Animal models, nowadays, are the most appropriate approach to uncovering this knowledge gap. In the present review article, we explore investigations from the last two years using rodent models and reach to find the molecular mechanism behind micro- and nanoplastics toxicity and if mitochondria can act as a target. Although no research article has addressed the effects of mitochondria yet, reports have highlighted molecular and biochemical alterations that could be linked to mitochondrial function. Furthermore, certain studies described the effects of disruptions in mitochondrial metabolism, such as oxidative stress. Micro- and nanoplastics may, directly and indirectly, affect this vital organelle. Investigations concerning this topic should be encouraged once they can bring us closer to understanding the mechanisms underlying these particles' harmful effects on human health.

Polytetrafluorethylene microplastic particles mediated oxidative stress, inflammation, and intracellular signaling pathway alteration in human derived cell lines

Microplastics (MPs) are now widely distributed across the aerial, terrestrial, and aquatic environments. Thus, exposure to MPs via the oral, inhalation, or dermal routes is inevitable. Polytetrafluoroethylene (PTFE)-MPs is mainly used for manufacturing nonstick cookware, semiconductors, and medical devices; however, their toxicity has been rarely studied. In the present study, six different human cell lines, which are representative of tissues and cells that directly or indirectly come into contact with MPs, were exposed to two different sizes of irregular shape PTFE-MPs (with an average diameter of 6.0 or 31.7 μm). PTFE-MPs-mediated cytotoxicity, oxidative stress, and changes in proinflammatory cytokine production were then evaluated. We found that the PTFE-MPs did not induce cytotoxicity under any of the experimental conditions. However, PTFE-MPs (especially average diameter of 6.0 μm) induced nitric oxide and reactive oxygen species production in all the cell lines tested. Moreover, both sizes of PTFE-MPs increased the secretion of tumor necrosis factor alpha and interleukin-6 from the U937 macrophage cell line and the A549 lung epithelial cell line, respectively. In addition, PTFE-MPs activated the MAPK signaling pathways, especially the ERK pathway, in A549 and U937 cells, and in the THP-1 dendritic cell line. We also found that the expression of the NLRP3 inflammasome was reduced in the U937 and THP-1 cell lines following treatment with the PTFE-MPs sized 31.7 μm average diameter. Furthermore, expression of the apoptosis regulator, BCL2, was markedly increased in the A549 and U937 cell lines. Thus, although PTFE-MPs exert different effects on different cell types, our findings suggest that PTFE-MPs-associated toxicity may be specifically linked to the activation of the ERK pathway, which ultimately induces oxidative stress and inflammation.

The emerging role of microplastics in systemic toxicity: Involvement of reactive oxygen species (ROS)

Plastic pollution is one of the most pressing environmental threats the world is facing currently. The degradation of macroplastics into smaller forms viz. microplastics (MPs) or Nanoplastics (NPs) is a potential threat to both terrestrial and marine ecosystems and also to human health by directly affecting the organs and activating a plethora of intracellular signaling, that may lead to cell death. There is accumulating evidence that supports the serious toxicity caused by MP/NPs at all levels of biological complexities (biomolecules, organelles, cells, tissues, organs, and organ systems) and the involvement of the reactive oxygen species (ROS) in this process. Studies indicate that MPs or NPs can accumulate in mitochondria and further disrupt the mitochondrial electron transport chain, cause mitochondrial membrane damage, and perturb the mitochondrial membrane potential or depolarization of the mitochondria. These events eventually lead to the generation of different types of reactive free radicals, which can induce DNA damage, protein oxidation, lipid peroxidation, and compromization of the antioxidant defense pool. Furthermore, MP-induced ROS was found to trigger a plethora of signaling cascades, such as the p53 signaling pathway, Mitogen-activated protein kinases (MAPKs) signaling pathway including the c-Jun N-terminal kinases (JNK), p38 kinase, and extracellular signal related kinases (ERK1/2) signaling cascades, Nuclear factor erythroid 2-related factor 2 (Nrf2)-pathway, Phosphatidylinositol-3-kinases (PI3Ks)/Akt signaling pathway, and Transforming growth factor-beta (TGF-β) pathways, to name a few. As a consequence of oxidative stress caused by the MPs/NPs, different types of organ damage are observed in living species, including humans, such as pulmonary toxicity, cardiotoxicity, neurotoxicity, nephrotoxicity, immunotoxicity, reproductive toxicity, hepatotoxicity, etc. Although presently, a good amount of research is going on to access the detrimental effects of MPs/NPs on human health, there is a lack of proper model systems, multi-omics approaches, interdisciplinary research, and mitigation strategies.

Gut Microbiota Participates in Polystyrene Microplastics-Induced Hepatic Injuries by Modulating the Gut-Liver Axis

Dietary pollution by polystyrene microplastics (MPs) can cause hepatic injuries and microbial dysbiosis. Epigallocatechin-3-gallate (EGCG), the major polyphenol in green tea, exerts beneficial effects on the liver by modulating the gut microbiota. However, the role of microbiota in MPs-induced hepatic injuries and the protective effect of EGCG have not been clarified. Here, 5 μm MPs were orally administered to mice to induce hepatic injuries. Subsequently, antibiotic cocktail (ABX) and fecal microbial transplant (FMT) experiments were performed to investigate the underlying microbial mechanisms. Additionally, EGCG was orally administered to mice to explore its protection against MPs-induced hepatic injuries. Our results showed that MPs activated systemic and hepatic inflammation, promoted fibrosis, and altered the liver metabolome; meanwhile, MPs damaged the gut homeostasis by disturbing the gut microbiome, promoting colonic inflammation, and impairing the intestinal barrier. Notably, MPs reduced the abundance of the probiotics Akkermansia, Mucispirillum, and Faecalibaculum while increasing the pathogenic Tuzzerella. Interestingly, the elimination of gut microbiota mitigated MPs-induced colonic inflammation and intestinal barrier impairment. Moreover, ABX ameliorated MPs-induced systemic and hepatic inflammation but not fibrosis. Correspondingly, microbiota from MPs-administered mice induced colonic, systemic, and hepatic inflammation, while their profibrosis effect on the liver was not observed. Finally, EGCG elevated the abundance of probiotics and effectively repressed MPs-induced colonic inflammation. MPs-induced systemic and hepatic inflammation, fibrosis, and remodeling of the liver metabolome were also attenuated by EGCG. These findings illustrated that gut microbiota contributed to MPs-induced colonic and hepatic injuries, while EGCG could serve as a potential prevention strategy for these adverse consequences.

Co-exposure to polystyrene microplastics and di-(2-ethylhexyl) phthalate aggravates allergic asthma through the TRPA1-p38 MAPK pathway

Increasing attention has been paid to the potential impact of microplastics (MPs) pollution on human health. MPs and phthalates coexist in the environment, however, the effects of exposure to MPs alone or to a combination of di-(2-ethylhexyl) phthalate (DEHP) and MPs on allergic asthma are unclear. This study investigates the effects of exposure to polystyrene microplastics (PS-MPs) or co-exposure with DEHP, on allergic asthma, and the underlying molecular mechanisms. We established an allergic asthma model using ovalbumin, and mice were exposed to PS-MPs (5 mg/kg bw/day) alone, or combined with DEHP (0.5, 5 mg/kg bw/day), for 28 days. The results showed that in the presence of ovalbumin (OVA) sensitization, exposure to PS-MPs alone slightly affected airway inflammation, and airway hyperresponsiveness, while co-exposure to PS-MPs and DEHP caused more significant damage. Co-exposure also induced more oxidative stress and Th2 immune responses, and activation of the TRPA1 and p38 MAPK pathways. The aggravation of asthmatic symptoms induced by co-exposure to PS-MPs and DEHP were inhibited by blocking TRPA1 ion channel or p38 MAPK pathway. The results demonstrated that co-exposure to PS-MPs and DEHP exacerbates allergic asthma, by exacerbating oxidative stress and inflammatory responses, and activating the TRPA1-p38 MAPK pathway.

Attenuative effect of astilbin on polystyrene microplastics induced testicular damage: Biochemical, spermatological and histopathological-based evidences

Polystyrene microplastics (PS-MPs) are the potential environmental pollutants that possess the ability to induce testicular damage. Astilbin (ASB) is a dihydroflavonol, abundantly reported in multiple plants that has various pharmacological properties. This research elucidated the mitigative potential of ASB against PS-MPs-instigated testicular toxicity. 48 adult male rats (200 ± 10 g) were distributed into 4 groups (n = 12): control, PS-MPs received (0.01 mg/kg), PS-MPs + ASB received (0.01 mg/kg + 20 mg/kg) and ASB supplemented group (20 mg/kg). After 56th day of the trial, animals were sacrificed and testes were harvested for the estimation of biochemical, hormonal, spermatogenic, steroidogenic, apoptotic and histological profiles. PS-MPs intoxication significantly (P < 0.05) lowered glutathione peroxidase (GPx), superoxide dismutase (SOD), glutathione reductase (GSR) as well as catalase (CAT) activities, whereas elevated MDA as well as ROS levels. Besides, the levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), nuclear factor kappa-B (NF-κB) along with cyclooxygenase-2 (COX-2) activity were raised. PS-MPs treatment reduced luteinizing hormone (LH), plasma testosterone and follicle-stimulating hormone (FSH) level besides decreased epididymal sperm number, viability, motility as well as the count of HOS coil-tailed spermatozoa and increased sperm morphological irregularities. PS-MPs exposure lowered steroidogenic enzymes (17β-HSD, 3β-HSD and StAR protein along with Bcl-2 expression, besides increasing Caspase-3 and Bax expressions and histopathological alterations in testicular tissues. However, ASB treatment significantly reversed PS-MPs mediated damage. In conclusion, ASB administration is protective against PS-MPs-instigated testicular damage owing to its anti-inflammatory, anti-apoptotic, antioxidant and androgenic nature.

Polystyrene microplastics promote liver inflammation by inducing the formation of macrophages extracellular traps

Microplastics (MPs), a new and increasing environmental pollutant, can cause ongoing damage to organisms. Although recent studies have revealed mechanisms of action for some of the hepatotoxicity caused by MPs, the role-played by cellular interactions, particularly immune cells, in the process of liver injury has not been elucidated. In the present study, 5-μm polystyrene microplastics (PS-MPs) induced liver inflammation as well as the formation of Macrophage extracellular traps (METs). Macrophage and LMH cell co-culture systems confirmed that PS-MPs-induced METs promote inflammation in hepatocytes. Mechanistically, macrophages actively phagocytose particles after 4 h of exposure to PS-MPs. Subsequently PS-MPs elevated ROS levels and disrupt mitochondrial kinetic homeostasis. Further activation of mitochondrial autophagy and lysosomes. After phagocytosis of PS-MPs by macrophages for 12 h, continued autophagy and lysosome activation eventually lead to lysosome rupture and release of calcium ions to induce the formation of METs. Blocking ROS (NAC) and autophagy (3MA) partially alleviated mitochondrial and lysosomal damage and thus inhibited the formation of METs induced by PS-MPs. NAC also delayed the onset of respiratory burst to alleviate METs formation. In conclusion, our study reveals the mechanism of METs formation in liver inflammation induced by PS-MPs exposure and suggests that lysosomal damage may be one of the key players in the formation of METs induced by PS-MPs.

Sulfate-modified nanosized polystyrene impairs memory by inhibiting ionotropic glutamate receptors and the cAMP-response element binding protein (CREB) pathway in Caenorhabditis elegans

Nanoplastic contamination is an emerging environmental concern worldwide. In particular, sulfate anionic surfactants often appear along with nanosized plastic particles in personal care products, suggesting that sulfate-modified nanosized polystyrene (S-NP) may occur, remain, and spread into the environment. However, whether S-NP adversely affects learning and memory is unknown. In this study, we used a positive butanone training protocol to evaluate the effects of S-NP exposure on short-term associative memory (STAM) and long-term associative memory (LTAM) in Caenorhabditis elegans. We observed that long-term S-NP exposure impairs both STAM and LTAM in C. elegans. We also observed that mutations in the glr-1, nmr-1, acy-1, unc-43, and crh-1 genes eliminated the STAM and LTAM impairment induced by S-NP, and the mRNA levels of these genes were also decreased upon S-NP exposure. These genes encode ionotropic glutamate receptors (iGluRs), cyclic adenosine monophosphate (cAMP)/Ca²⁺ signaling proteins, and cAMP-response element binding protein (CREB)/CRH-1 signaling proteins. Moreover, S-NP exposure inhibited the expression of the CREB-dependent LTAM genes nid-1, ptr-15, and unc-86. Our findings provide new insights into long-term S-NP exposure and the impairment of STAM and LTAM, which involve the highly conserved iGluRs and CRH-1/CREB signaling pathways.

Adverse health effects and mechanisms of microplastics on female reproductive system: a descriptive review

Microplastics (MPs), with a diameter of less than 5 mm, include polymers such as polystyrene, polypropylene, and polyethylene. The MPs occur in different morphologies including fragments, beads, fibers, and films that are swallowed by fresh water and land-based animals and enter their food chain, where they produce hazardous effects such as uterine toxicity, infertility, and neurotoxicity. The aim of this review is to explore the effects of polystyrene MPs (PS-MPs) on the female reproductive system and understand the mechanisms by which they produce reproductive toxicity. Several studies suggested that the exposure to PS-MPs increased the probability of larger ovaries with fewer follicles, decreased the number of embryos produced, and decreased the number of pregnancies in female mice. It also changed sex hormone levels and caused oxidative stress, which could have an impact on fertility and reproduction. Exposure to PS-MPs caused the death of granulosa cells through apoptosis and pyroptosis via activation of the NLRP3/caspase pathway and disruption of the Wnt-signaling pathway. Activation of TL4/NOX2 caused the uterine fibrosis resulting in endometrium thinning. The PS-MPs had a negative impact on ovarian capacity, oocyte maturation, and oocyte quality. Furthermore, the PS-MPs disrupted the hypothalamus-pituitary-gonadal axis in marine animals, resulting in a decrease in hatching rate and offspring body size, causing trans-generational effects. It also reduced fecundity and produced germ-line apoptosis. The main focus of this review was to explore the different mechanisms and pathways through which PS-MPs adversely impact the female reproductive system.

Polystyrene micro- and nanoparticles exposure induced anxiety-like behaviors, gut microbiota dysbiosis and metabolism disorder in adult mice

Plastics have been proven to be a potential threat to the ecosystem, and their toxicity mechanism is still uncertain. In the ecological environment, plastics can be degraded into microplastics (MPs) and nanoplastics (NPs), which can be contaminated and ingested through the food chain. MPs and NPs are associated with severe intestinal injury, intestinal microbiota disorder, and neurotoxicity, but it is still unclear whether MPs- and NPs-induced intestinal microbiota dysbiosis will affect the brain through the gut-brain axis. In the current study, we determined the effects of exposure to polystyrene (PS)-MPs and PS-NPs on anxiety-like behaviors and explored the underlying mechanisms. This study explored the behavioral effects of 30-day and 60-day exposure to PS-NPs and PS-MPs using the open field test (OFT) and elevated plus maze (EPM) test. Behavioral tests showed PS-NPs and PS-MPs treatment remarkedly induced anxiety-like behaviors compared with the control group. Using 16 S rRNA gene sequencing and untargeted metabolomics analyses, we observed that PS-MPs and PS-NPs exposure reduced the beneficial gut microbiota expression level, such as Lachnoclostridium and Lactobacillus, and increased the conditionally pathogenic bacteria expressions level, such as Proteobacteria, Actinobacteria, and Desulfovibrio. In addition, PS-NPs and PS-MPs reduce intestinal mucus secretion and increase intestinal permeability. The results of serum metabonomics suggested that the metabolic pathways, such as ABC transporter pathways, aminoacyl-tRNA biosynthesis, biosynthesis of amino acids, and bile secretion were enriched after PS-NPs and PS-MPs treatment. Besides, neurotransmitter metabolites were also altered by PS-NPs and PS-MPs. It is noteworthy that the correlation analysis showed that the disorder of intestinal microbiota was related to anxiety-like behaviors and neurotransmitter metabolites disorder. The regulation of intestinal microbiota may be a promising treatment strategy for PS-MPs- and PS-NPs-induced anxiety disorder.

Characterizing the binding interactions between virgin/aged microplastics and catalase in vitro

Microplastics (MPs) undergo physical, chemical, and biological aging in the environment, leading to changes in their physicochemical properties, affecting migration characteristics and toxicity. Oxidative stress effects induced by MPs in vivo have been extensively studied, but the toxicity difference between virgin and aged MPs and the interactions between antioxidant enzymes and MPs in vitro have not been reported yet. This study investigated the structural and functional changes of catalase (CAT) induced by virgin and aged PVC-MPs. It was shown that light irradiation aged the PVC-MPs, and the aging mechanism was photooxidation, resulting in a rough surface and appearing holes and pits. Because of the changes in physicochemical properties, aged MPs had more binding sites than virgin MPs. Fluorescence and synchronous fluorescence spectra results suggested that MPs quenched the endogenous fluorescence of CAT and interacted with tryptophane and tyrosine residues. The virgin MPs had no significant effect on the skeleton of CAT, while the skeleton and the polypeptide chains of CAT became loosened and unfolded after binding with the aged MPs. Moreover, the interactions of CAT with virgin/aged MPs increased the α-helix and decreased the β-sheet contents, destroyed the solvent shell, and resulted in a dispersion of CAT. Due to the large size, MPs cannot enter the interior of CAT and have no effects on the heme groups and activity of CAT. The interaction mechanism between MPs and CAT may be that MPs adsorb CAT to form the protein corona, and aged MPs had more binding sites. This study is the first comprehensive investigation of the effect of aging on the interaction between MPs and biomacromolecules and highlights the potential negative effects of MPs on antioxidant enzymes.

Polystyrene microplastics mediate inflammatory responses in the chicken thymus by Nrf2/NF-κB pathway and trigger autophagy and apoptosis

Microplastics (MPs) are now a hot environmental contaminant. However, researchers paid little attention to their effects on immune organs such as the thymus. Here, we exposed chickens to a concentration gradient of polystyrene microplastics (PS-MPs) and then followed the decrease in the thymus index. HE staining showed cellular infiltration in the thymus. The assay kit corroborated that PS-MPs impelled oxidative stress in the thymus: increased MDA levels, downregulated antioxidants such as SOD, CAT, and GSH, and significantly undermined total antioxidant capacity. Western blotting and qRT-PCR results showed that Nrf2/NF-κB, Bcl-2/Bax, and AKT signaling pathways were activated in the thymus after exposure to PS-MPs. It stimulated the increased expression of downstream such as IL-1β, caspase-3, and Beclin1, triggering thymus inflammation, apoptosis, and autophagy. This study provides new insights into the field of microplastic immunotoxicity and highlights potential environmental hazards in poultry farming.

Exposure to nanoplastics induces mitochondrial impairment and cytomembrane destruction in Leydig cells

Plastic particle pollution poses an emerging threat to ecological and human health. Laboratory animal studies have illustrated that nano-sized plastics can accumulate in the testis and cause testosterone deficiency and spermatogenic impairment. In this study, TM3 mouse Leydig cells were in vitro exposed to polystyrene nanoparticles (PS-NPs, size 20 nm) at dosages of 50, 100 and 150 μg/mL to investigate their cytotoxicity. Our results demonstrated that PS-NPs can be internalized into TM3 Leydig cells and led to a concentration-dependent decline in cell viability. Furthermore, PS-NPs stimulation amplified ROS generation and initiated cellular oxidative stress and apoptosis. Moreover, PS-NPs treatment affected the mitochondrial DNA copy number and collapsed the mitochondrial membrane potential, accompanied by a disrupted energy metabolism. The cells exposed to PS-NPs also displayed a down-regulated expression of steroidogenesis-related genes StAR, P450scc and 17β-HSD, along with a decrease in testosterone secretion. In addition, treatment with PS-NPs destructed plasma membrane integrity, as presented by increase in lactate dehydrogenase release and depolarization of cell membrane potential. In summary, these data indicated that exposure to PS-NPs in vitro produced cytotoxic effect on Leydig cells by inducing oxidative injury, mitochondrial impairment, apoptosis, and cytomembrane destruction. Our results provide new insights into male reproductive toxicity caused by NPs.

Pinostrobin alleviates testicular and spermatological damage induced by polystyrene microplastics in adult albino rats

BACKGROUND

Polystyrene microplastics (PS-MPs) have become major environmental pollutants that adversely effects multiple organs specifically testicles. Pinostrobin (PN) is an important flavonoid which, shows several pharmacological potentials.

PURPOSE

The current study was designed to elucidate the mitigative effects of PN against PS-MPs induced testicular toxicities in rats.

METHODS

48 male albino rats were randomly distributed into 4 groups, control, PS-MPs group (0.01 mg/kg), PS-MPs + PN group (0.01 mg/kg of PS-MPs; 40 mg/kg of PN) and PN group (40 mg/kg).

RESULTS

PS-MPs intoxication substantially lessened the activities of glutathione peroxidase (GPx), glutathione reductase (GSR), superoxide dismutase (SOD) along with catalase (CAT) while, raised the level of malondialdehyde (MDA) as well as reactive oxygen species (ROS). Additionally, PS-MPs reduced luteinizing hormone (LH), plasma testosterone, follicle-stimulating hormone (FSH) concentration, sperm motility, sperm count, expression of steroidogenic enzymes and Bcl-2 (anti-apoptotic protein) along with the count of spermatogenic cells. While, dead sperm count, sperm abnormalities (tail, neck and head), Bax and caspase-3 (apoptotic proteins) expression along with histopathological anomalies were elevated. Moreover, PS-MPs exposure increased the level of inflammatory markers. However, PN treatment considerably decreased oxidative stress (OS) by reducing ROS as well as increased sperm motility and alleviated all the damages induced by the PS-MPs.

CONCLUSION

Therefore, it is concluded that PN may prove a potential therapeutic candidate to restore all the PS-MPs-induced testicular toxicities.

Polystyrene microplastics arrest skeletal growth in puberty through accelerating osteoblast senescence

Polystyrene microplastics (PS-MPs) have attracted worldwide attention to their massive accumulation in terrestrial and aquatic ecosystems. It has been demonstrated that MPs are easily to accumulate in organs and exert toxic effects. However, their exposure risk to the skeleton remains unknown. In this study, we observed PS-MPs accumulation in both the long bones and axial bones, leading to reduced body length, as well as femur and tibia length. PS-MPs treated mice exhibited redundant skeletal growth and impaired trabecular bone micro-architecture, which is due to the suppressed osteogenic ability as the number of osteoblasts decreased significantly in PS-MPs treated mice. In histological analysis, we observed the accumulation of senescent osteoblasts in the bone trabecula of PS-MPs treated mice, as well as the impaired autophagy with decreased autophagosome and reduced autophagy-related proteins in the senescent osteoblasts. Re-establishing autophagy effectively reversed the senescent phenotype in osteoblasts and ameliorated PS-MPs induced skeletal growth arrest. Hence, our study reveals the detrimental role of PS-MPs in skeletal growth in puberty through accelerating osteoblast senescence, which may be alleviated by reactivating the autophagy. This study provides new evidence of the PS-MPs on health threats and the potential therapeutic targets to reverse it.

Prenatal and postnatal exposure to polystyrene microplastics induces testis developmental disorder and affects male fertility in mice

Polystyrene microplastics (PS-MPs) can threaten human health, especially male fertility. However, most existing studies have focused on the adulthood stage of male reproduction toxicity caused by relatively short-term PS-MP exposure. This study aimed to investigate the toxic effect of PS-MPs on testicular development and reproductive function upon prenatal and postnatal exposure. Pregnant mice and their offspring were exposed to 0, 0.5 mg/L, 5 mg/L, and 50 mg/L PS-MPs through their daily drinking water from gestational day 1 to postnatal day (PND) 35 or PND70. We found that PS-MP exposure induced testis development disorder by PND35 and spermatogenesis dysfunction by PND70. By combining RNA sequencing results and bioinformatics analysis, the hormone-mediated signaling pathway, G1/S transition of the mitotic cell cycle, coregulation of androgen receptor activity, and Hippo signaling pathway were shown to be involved in testis development on PND35. The meiotic cell cycle, regulation of the immune effector process, neutrophil degranulation, and inflammation mediated by chemokine and cytokine signaling pathways were associated with disturbed spermatogenesis on PND70. These findings show that prenatal and postnatal exposure to PS-MPs resulted in testis development disorder and male subfertility, which may be regulated by the Hippo signaling pathway and involve an immune reaction.

Polystyrene nanoplastics inhibit StAR expression by activating HIF-1α via ERK1/2 MAPK and AKT pathways in TM3 Leydig cells and testicular tissues of mice

Microplastics (MPs) and nanoplastics (NPs) are widely found in water, food and air, and have been found in human blood, lung and feces. Several studies in vivo have shown that MPs and NPs decrease testosterone level. However, the molecular mechanism of MPs and NPs leading to testosterone reduction remains unclear. In the present study, mice were treated with 50 μg/kg·day polystyrene (PS)-NPs by tail vein injection once daily for two consecutive days, the mRNA and protein levels of steroidogenic acute regulatory protein (StAR) decreased significantly in testis. TM3 Leydig cells were treated with non-toxic doses of PS-NPs, hypoxia-inducible factor-1α (HIF-1α) mRNA translation was induced by PS-NPs through mTOR/4E-BP1 pathway, which was activated by the ERK1/2 MAPK and AKT pathways. Simultaneously, increased HIF-1α protein inhibited StAR transcription. Additionally, reactive oxygen species production induced by PS-NPs played a central role in the activation of ERK1/2 MAPK/mTOR and AKT/mTOR signaling pathways. These results suggest that PS-NPs down-regulate StAR expression by increasing HIF-1α, which is induced by activation of mTOR/4E-BP1 through the ERK1/2 MAPK and AKT signaling pathways. Our findings provide new insight into the potential molecular mechanism by which PS-NPs impair testosterone synthesis and male reproductive function.

Male reproductive toxicity of polystyrene microplastics: Study on the endoplasmic reticulum stress signaling pathway

Microplastics (MPs) have raised health concerns in public for its potential reproductive toxicity. In this study, we subjected the Kunming mice to 0.01, 0.1 and 1.0 mg/day polystyrene MPs (10 μm, PS-MPs) for 35 days, aiming to investigate the relevant male reproductive toxicity and latent molecular mechanism. The results showed the decreased sperm counts and motility, while the elevated sperm abnormality in PS-MPs-exposed mice. Testicular H&E staining displayed the vacuolization, atrophy, and even shedding of germ cells in seminiferous tubule. And the testosterone content in serum also decreased with PS-MPs treatment. Moreover, molecular analysis indicated that PS-MPs upregulated the expression trait factors for ERS (e.g., immunoglobulin-binding protein [BIP], inositol-requiring protein 1α [IRE1α], X-box-binding protein 1 splicing [XBP1s], Jun kinase [JNK], and the transcription of CCAAT/enhancer-binding protein (C/EBP) homologous protein [CHOP]) and downstream apoptotic modulator (e.g., Caspase-12, -9, and -3) in the testis. The steroidogenic acute regulatory protein (StAR), the testosterone synthetic initiator, was also downregulated. With the supplementation of ERS inhibitor, the MPs-induced testicular damage and decreased testosterone were improved to almost normal level. Overall, this study suggested that PS-MPs generate reproductive toxicity possibly via activating ERS and apoptosis signaling pathway.

Exposure to polystyrene nanoplastics induces an anxiolytic-like effect, changes in antipredator defensive response, and DNA damage in Swiss mice

Although the in vivo toxicity of nanoplastics (NPs) has already been reported in different model systems, their effects on mammalian behavior are poorly understood. Thus, we aimed to evaluate whether exposure to polystyrene (PS) NPs (diameter: 23.03 ± 0.266 nm) alters the behavior (locomotor, anxiety-like and antipredator) of male Swiss mice, induces brain antioxidant activity, and erythrocyte DNA damage. For this, the animals were exposed to NPs for 20 days at different doses (6.5 ng/kg and 6500 ng/kg). Initially, we did not observe any effect of pollutants on the locomotor activity of the animals (inferred via open field test and Basso mouse scale for locomotion). However, we noticed an anxiolytic-like behavior (in the open field test) and alterations in the antipredatory defensive response of mice exposed to PS NPs, when confronted with their predator potential (snake, Pantherophis guttatus). Furthermore, such changes were associated with suppressing brain antioxidant activity, inferred by lower DPPH radical scavenging activity, reduced total glutathione content, as well as the translocation and accumulation of NPs in the brain of the animals. In addition, we noted that the treatments induced DNA damage, evaluated via a single-cell gel electrophoresis assay (comet assay) applied to circulating erythrocytes of the animals. However, we did not observe a dose-response effect for all biomarkers evaluated and the estimated accumulation of PS NPs in the brain. The values of the integrated biomarker response index and the results of the principal component analysis (PCA) and the hierarchical clustering analysis confirmed the similarity between the responses of animals exposed to different doses of PS NPs. Therefore, our study sheds light on how PS NPs can impact mammals and reinforce the ecotoxicological risk associated with the dispersion of these pollutants in natural environments and their uptake by mammals.

Adverse effects of pristine and aged polystyrene microplastics in mice and their Nrf2-mediated defense mechanisms with tissue specificity

Health hazards associated with microplastics (MPs) remain largely unknown, and the effects of aged MPs, one of their persistent forms, are poorly characterized. Male ICR mice were intratracheally instilled with 0.01 and 1 mg/day pristine and ultraviolet (UV)-aged polystyrene microplastics (PS and APS) with an average diameter of 4 - 5 μm daily for 1 week. UV irradiation caused the PS to have a rough surface, become fragmented, and increase their carbonyl groups. Both PS and APS caused structural damage to the mouse gut, liver, spleen, and testis. Inflammatory infiltration in liver, swollen and congested gut, and loose spleen globules, as well as the loose interstitium of the seminiferous tubules in testis were found in 1 mg/day APS group. Increases in serum alanine aminotransferase and immunoglobulin A levels in 1 mg/day APS group (p < 0.05) demonstrated that APS exposure could induce greater liver and spleen functional damage than PS. Meanwhile, triglyceride and total cholesterol levels in liver were enhanced in 1 mg/day APS group (p < 0.05). Superoxide dismutase and glutathione contents in 0.01 and 1 mg/day APS groups significantly decreased (p < 0.05), which suggesting that PS and APS could interfere with the antioxidant capacity in mice. Nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) levels in the PS and APS groups showed significant increases in the liver and testis (p < 0.05), and a significant decrease in the spleen (p < 0.05), which were analyzed to get a first survey for Nrf2/HO-1-mediated tissue-specific defense mechanisms. In conclusion, acute exposure to PS and APS induced potential metabolic disorders, and APS could produce more serious immune damage and reproductive toxicity. These findings provide new insights in health risk assessment of aged MPs.

The Chemical Composition Characteristics and Health Risk Assessment of Cooking Fume Condensates from Residential Kitchens in Different Regions of China

The aim of this study was to explore the similarities and differences of volatile organic pollutants (VOCs) in cooking fumes (COF) of residential buildings in different regions of China, as well as to evaluate their potential health risks. COF condensates were collected from 10 representative cities in China and analyzed by a GC-MS method. Their effects on α-glucosidase, acetylcholinesterase (AchE), and lactate dehydrogenase (LDH) activities were then detected to evaluate potential health risks. A total of 174 kinds of VOCs, including aldehydes, esters, hydrocarbons, alcohols, and carboxylic acid, were identified. There were 59 identical compounds in the northern and southern regions, and 56 common compounds in spicy and non-spicy regions. Health risk assessment results showed that COF condensate could inhibit the activity of α-glucosidase to varying degrees (61.73-129.25%), suggesting that it had a potential risk of causing hypoglycemia. Daily and 3 and 6 month intakes of COF in minors, adults, and the elderly had both activated and inhibited effects on AchE. The activated effect in the southern and spicy areas was higher than that in northern and non-spicy areas, revealing that different regions and dietary habits had different effects on the risk of neurological diseases caused by changes in AchE activity. For minors, adults, and the elderly, COF had different degrees of activation of LDH at different exposure times and regions. Activation in the northern and non-spicy areas was higher than that in southern and spicy areas, suggesting that the health risks caused by changes in LDH activity levels were significantly increased.