Cognitive Impairment and Neurodegenerative Diseases Development Associated with Organophosphate Pesticides Exposure: a Review Study

The role of CXCL12/CXCR4/CXCR7 axis in cognitive impairment associated with neurodegenerative diseases

Neurodegenerative diseases, including Alzheimer's Disease (AD), Parkinson's Disease (PD), Multiple Sclerosis (MS), and Amyotrophic Lateral Sclerosis (ALS), are characterized by progressive neuronal loss and cognitive impairment (CI). The: Cysteine-X-cysteine chemokine ligand 12(CXCL12)/CXC chemokine receptor type 4 (CXCR4)/CXC chemokine receptor type 7 (CXCR7) axis has emerged as a critical molecular pathway in the development of CI in these disorders. This review explores the role of this axis in the pathogenesis of CI across these neurodegenerative diseases, synthesizing current evidence and its implications for targeted therapies. In AD, dysregulation of this axis contributes to amyloid-β accumulation and tau hyperphosphorylation, leading to synaptic dysfunction and cognitive decline. PD studies reveal that CXCL12/CXCR4 signaling influences dopaminergic neuron survival and microglial activation, affecting cognitive function. In MS, the axis modulates neuroinflammation and demyelination processes, impacting cognitive performance. ALS research indicates that the CXCL12/CXCR4/CXCR7 pathway is involved in motor neuron degeneration and associated cognitive deficits. Across these diseases, the axis influences neuroinflammation, synaptic plasticity, and neuronal survival through various signaling cascades, including PI3K/AKT, MAPK, and JAK/STAT pathways. Emerging evidence suggests that modulating this axis could provide neuroprotective effects and potentially alleviate cognitive symptoms. This review highlights the potential of the CXCL12/CXCR4/CXCR7 axis as a therapeutic target for addressing CI in neurodegenerative diseases. It also underscores the need for further research to fully elucidate its role and develop effective interventions, potentially leading to improved clinical management strategies for these devastating disorders.

Neuroinflammation and neurodegeneration in Huntington's disease: genetic hallmarks, role of metals and organophosphates

Huntington's disease (HDs) is a fatal, autosomal dominant, and hereditary neurodegenerative disorder characterized by progressive motor dysfunction, cognitive decline, and psychiatric disturbances. HD is well linked to mutation in the HTT gene, which leads to an abnormal expansion of trinucleotide CAG repeats, resulting in the production of the mHTT protein and responsible for abnormally long poly-Q tract. These abnormal proteins disrupt cellular processes, including neuroinflammation, endoplasmic reticulum (ER) stress, and mitochondrial dysfunction, ultimately leading to selective neuronal loss in the brain. Epidemiological studies reveal significant regional variability in HDs prevalence, with the highest rates observed in North America and the lowest in Africa. In addition to genetic factors, environmental influences such as exposure to metals, and chemicals, and lifestyle factors like alcohol and tobacco use may exacerbate disease progression. This review explores the molecular mechanisms underlying HDs and emphasize the role of neuroinflammatory mediators and environmental factors, in HD research. Understanding these complex interactions is crucial for developing targeted interventions that can slow or halt the progression of this devastating disease.

Prenatal exposure to a mixture of organophosphate ester and organophosphorus pesticides in relation to child neurodevelopment in the Shanghai Birth Cohort

Neurotoxicity of organophosphate esters (OPEs) and organophosphorus pesticides (OPPs) has been documented in toxicological studies, though epidemiological evidence remains inconsistent. The developing fetal brain is susceptible to environmental exposures. Thus, we aim to investigate how prenatal exposure to OPEs and OPPs as mixture affects offspring neurodevelopment in preschool-aged children. In a study involving 530 mother-child dyads from the Shanghai Birth Cohort (SBC) with enrollment occurring between 2013 and 2016, 14 OPEs/OPPs metabolites were evaluated using high-performance liquid chromatography/tandem mass spectrometry (HPLC/MS-MS) in maternal urine collected during both the first and second trimester. Child neurodevelopment was evaluated using the parent-reported Behavior Rating Inventory of Executive Function-Preschool version (BRIEF-P) and the Strengths and Difficulties Questionnaire (SDQ). We utilized multivariable linear regression and Bayesian kernel machine regression (BKMR) to estimate associations with individual and mixture component, respectively. We also investigated whether these associations varied by child sex. Of the 14 OPEs/OPPs metabolites, 6 were quantifiable in over 75 % of the samples. Higher prenatal O,O-dimethyl phosphate (DMP) concentrations in the first and second trimesters, as well as O,O-dimethyl thiophosphate (DMTP) in the second trimester, were associated with more behavioral difficulties. When stratified by child sex, the statistically significant inverse associations were observed exclusively in girls. Results from BKMR showed that the overall effect of prenatal exposure to OPEs and OPPs mixtures was associated with some neurodevelopmental domains in girls. For example, holding the mixture at the 75th percentile compared to the 50th percentile during the first trimester was associated with a 0.65 increase in SDQ total scores (95 % confidence interval: 0.03-1.26). DMP and DMTP may be the dominant contributors. Our findings add to the literature on the effect of prenatal exposure to OPEs and OPPs on offspring neurodevelopment and suggest that the effect seems to be sex-specific. Additional research is required to validate our findings and elucidate the underlying mechanisms.

Nanopaper Integrated Smart Device: An Opto-Electrochemical Biosensor for Real-Time Dual On-Field Detection of Organophosphorus Pesticides

The frequent and excessive use of organophosphorus pesticides in the agriculture industry raises persistent concerns regarding their environmental protection and public health implications. Addressing these issues requires the development of affordable and reliable sensing platforms for on-field monitoring to mitigate their adverse impacts promptly. This study utilizes nanocellulose papers (bacterial and TEMPO-oxidized) combined with butyrylcholinesterase to create a novel reagent-free and orthogonal nanobioplatform featuring smart opto-electrochemical dual outputs. An integrated nano-PAD, preloaded with enzymes and enzymatic substrates, is fabricated using wax-printing and screen-printing technologies. The nano-PAD measures opto-electroactive products, specifically indoxyl and thiocholine, whose concentrations correlate directly with the enzymatic inhibition caused by paraoxon, used as the organophosphate model. To enhance user convenience and meet the requirements for smart real-time point-of-need detection, integration of the nano-PAD with a smartphone-operated miniaturized potentiostat and a self-developed portable smart optical reader is achieved. The developed bioanalytical platform, further supported by a self-developed Android application, enables accurate and efficient quantification of dual signals in real time. The system covers a wide detection range of paraoxon (20-100 ppb) and demonstrates reliable recovery levels (ranging from 98 to 107%) in a real matrix, specifically wastewater. Given these demonstrated capabilities, this innovative biosensing strategy holds substantial potential for practical application in environmental surveillance, facilitating timely and informed environmental management decisions, particularly in resource-limited settings where traditional analytical tools are inaccessible.

Implication of Pyrethroid Neurotoxicity for Human Health: A Lesson from Animal Models

Pyrethroids, synthetic insecticides used in pest management, pose health risks, particularly neurotoxic effects, with studies linking exposure to a neurodegenerative disorder. This review examines the neurotoxic mechanisms of pyrethroids analyzing literature from animal model studies. It identifies critical targets for neurotoxicity, including ion channels, oxidative stress, inflammation, neuronal cell loss, and mitochondrial dysfunction. The review also discusses key therapeutic targets and signaling pathways relevant to Pyrethroids neurotoxicity management, including calcium, Wnt/β-catenin, mTOR, MAPK/Erk, PI3K/Akt, Nrf2, Nurr1, and PPARγ. Our findings demonstrate that pyrethroid exposure triggers multiple neurotoxic pathways that bear resemblance to the mechanisms underlying neurotoxicity. Oxidative stress and inflammation emerge as prominent factors that contribute to neuronal degeneration, alongside disrupted mitochondrial function. The investigation highlights the significance of ion channels as primary neurodegeneration targets while acknowledging the potential involvement of various other receptors and enzymes that may exacerbate neurological damage. Additionally, we elucidate how pyrethroids may interfere with therapeutic targets associated with neuronal dysfunction, potentially impairing treatment efficacy.Also, exposure to these chemicals can alter DNA methylation patterns and histone modifications, ultimately leading to changes in gene expression that may enhance susceptibility to neurological disorders. Pyrethroid neurotoxicity poses a significant public health risk, necessitating future research for protective strategies against pesticide-induced neurological disorders and understanding the interplay between neurodegenerative diseases, potentially leading to innovative therapeutic interventions.

Chlorpyrifos-oxon induced neuronal cell death via endoplasmic reticulum stress-triggered apoptosis pathways

Chlorpyrifos (CPF) is one of the organophosphorus pesticides widely used throughout the world. Epidemiological studies suggested a link between CPF exposure and neurologic disorders, while the molecular mechanisms remain inconclusive. In the present study, we investigated the impacts of chlorpyrifos-oxon (CPO), the major toxic CPF metabolite, on cell apoptosis, and explored possible mechanism associated with endoplasmic reticulum (ER) stress in SH-SY5Y cells. Results showed that CPO exposure induced dose-dependent apoptosis and expression of ER stress-related proteins in SH-SY5Y cells. Pretreatment with 4-PBA (an ER stress inhibitor) effectively inhibited the expression of GRP78, GRP94, p-IRE1α, and XBP1-s, and apoptotic events. Pretreatment with STF-083010 (an IRE1α inhibitor) partially attenuated CPO-induced apoptosis. In addition, CPO exposure significantly evoked the generation of reactive oxygen species (ROS) which could be eliminated by pretreatment of 4-PBA. Of note, buffering the ROS generation with antioxidant NAC had little impact on the expression of p-IRE1α, and only partially attenuated CPO-induced apoptosis. In contrast, co-pretreatment with NAC and STF-083010 effectively inhibited CPO-induced apoptotic events. Collectively, our results indicate that CPO exposure exerts neuronal cytotoxicity via ER stress downstream-regulated IRE1α/XBP1 signaling pathway and ROS generation-triggered apoptosis. These findings highlight the role of ER stress in CPF-induced neurotoxicity, and provide a promising target for the intervention of organophosphate-associated neurodegenerative diseases.

Is exposure to pesticides associated with biological aging? A systematic review and meta-analysis

OBJECTIVE

Exposure to pesticides is a risk factor for various diseases, yet its association with biological aging remains unclear. We aimed to systematically investigate the relationship between pesticide exposure and biological aging.

METHODS

PubMed, Embase and Web of Science were searched from inception to August 2023. Observational studies investigating the association between pesticide exposure and biomarkers of biological aging were included. Three-level random-effect meta-analysis was used to synthesize the data. Risk of bias was assessed by the Newcastle-Ottawa Scale.

RESULTS

Twenty studies evaluating the associations between pesticide exposure and biomarkers of biological aging in 10,368 individuals were included. Sixteen reported telomere length and four reported epigenetic clocks. Meta-analysis showed no statistically significant associations between pesticide exposure and the Hannum clock (pooled β = 0.27; 95 %CI: -0.25, 0.79), or telomere length (pooled Hedges'g = -0.46; 95 %CI: -1.10, 0.19). However, the opposite direction of effects for the two outcomes showed an indication of possible accelerated biological aging. After removal of influential effect sizes or low-quality studies, shorter telomere length was found in higher-exposed populations.

CONCLUSION

The existing evidence for associations between pesticide exposure and biological aging is limited due to the scarcity of studies on epigenetic clocks and the substantial heterogeneity across studies on telomere length. High-quality studies incorporating more biomarkers of biological aging, focusing more on active chemical ingredients of pesticides and accounting for potential confounders are needed to enhance our understanding of the impact of pesticides on biological aging.

Association between organophosphorus insecticides exposure and osteoarthritis in patients with arteriosclerotic cardiovascular disease

BACKGROUND

Organic phosphorus insecticides (OPPs) are a class of environmental pollutants widely used worldwide with potential human health risks. We aimed to assess the association between exposure to OPPs and osteoarthritis (OA) particularly in participants with atherosclerotic cardiovascular disease (ASCVD).

METHODS

Participants' information was obtained from data in the National Health and Nutrition Examination (NHANES). Weighted logistic regression models were utilized to detect associations between OPPs metabolites and OA. Restricted cubic spline plots (RCS) were drawn to visualize the dose-response relationship between each metabolite and OA prevalence. Weighted quantile sum (WQS) regression and Bayesian kernel-machine regression (BKMR), were applied to investigate the joint effect of mixtures of OPPs on OA.

RESULTS

A total of 6871 samples were included in our study, no significant associations between OPPs exposure and OA incidence were found in whole population. However, in a subset of 475 individuals with ASCVD, significant associations between DMP (odds ratio [OR] as a continuous variable = 1.22, 95% confidence interval [CI]: 1.07,1.28), DEP ((odds ratio [OR] of the highest tertile compared to the lowest = 2.43, 95% confidence interval [CI]: 1.21,4.86), and OA were observed. DMP and DEP showed an increasing dose-response relationship to the prevalence of OA, while DMTP, DETP, DMDTP and DEDTP showed a nonlinear relationship. Multi-contamination modeling revealed a 1.34-fold (95% confidence intervals:0.80, 2.26) higher prevalence of OA in participants with high co-exposure to OPPs compared to those with low co-exposure, with a preponderant weighting (0.87) for the dimethyl dialkyl phosphate metabolites (DMAPs). The BKMR also showed that co-exposure of mixed OPPs was associated with an increased prevalence of OA, with DMP showing a significant dose-response relationship.

CONCLUSION

High levels of urine dialkyl phosphate metabolites (DAP) of multiple OPPs are associated with an increased prevalence of OA in patients with ASCVD, suggesting the need to prevent exposure to OPPs in ASCVD patients to avoid triggering OA and further avoid the occurrence of cardiovascular events caused by OA.

Revisiting the focal role of endostatin and environmental factors in Alzheimer's disease

Alzheimer's disease (AD) is a condition initiated by the assimilation of β-amyloid plaques (Aβ) and tau tangles, leading to neurodegeneration. It involves frequently cognitive decline as well as memory impairment in patients. Efforts in therapeutic interventions are currently facing challenges in identifying targets within this scaffold that can significantly alter the clinical course for individuals with AD. Moreover, in AD, neurons release a protein called endostatin, which accumulates in Aβ plaques and enhances AD. This accumulation of Aβ in the triggers a cascade of events leading to synaptic dysfunction, neuroinflammation, and ultimately neuronal death. Environmental factors nowadays increase the risk of AD with prolonged exposure of heavy metals such as copper (Cu), lead (Pb), mercury (Hg), cadmium (Cd), and other pesticides. It has been observed that these factors can cause the aggregation of Aβ and tau which initiates the plaque formation and hence leads to enhanced pathogenesis of AD. This review summarizes the interlinking between heavy metals, environmental factors, pesticides, endostatin, and progression of AD has been deliberated with recent findings.

Changes in motor behavior and lumbar motoneuron morphology following repeated chlorpyrifos exposure in rats

Chlorpyrifos is an organophosphate pesticide associated with numerous health effects including motor performance decrements. While many studies have focused on the health effects following acute chlorpyrifos poisonings, almost no studies have examined the effects on motoneurons following occupational-like exposures. The main objective of this study was to examine the broad effects of repeated occupational-like chlorpyrifos exposures on spinal motoneuron soma size relative to motor activity. To execute our objective, adult rats were exposed to chlorpyrifos via oral gavage once a day, five days a week for two weeks. Chlorpyrifos exposure effects were assessed either three days or two months following the last exposure. Three days following the last repeated chlorpyrifos exposure, there were transient effects in open-field motor activity and plasma cholinesterase activity levels. Two months following the chlorpyrifos exposures, there were delayed effects in sensorimotor gating, pro-inflammatory cytokines and spinal lumbar motoneuron soma morphology. Overall, these results offer support that subacute repeated occupational-like chlorpyrifos exposures have both short-term and longer-term effects in motor activity, inflammation, and central nervous system mechanisms.

Tiger nut/coconut dietary intervention as antidotal nutritional remediation strategy against neurobehavioural deficits following organophosphate-induced gut-brain axis dysregulation in mice

Organophosphate poisoning remains a global health crisis without efficacious treatments to prevent neurotoxicity. We examined whether antidotal tiger nut and coconut dietary intervention could ameliorate neurobehavioral deficits from organophosphate dichlorvos-induced gut-brain axis dysregulation in a mouse model. Mice were divided into groups given control diet, dichlorvos-contaminated diets, or dichlorvos plus nut-enriched diets. They were exposed to a DDVP-contaminated diet for 4 weeks before exposure to the treatment diets for another 8 weeks. This was followed by behavioural assessments for cognitive, motor, anxiety-, and depressive-like behaviours. Faecal samples (pre- and post-treatment), as well as blood, brain, and gut tissues, were collected for biochemical assessments following euthanasia. Dichlorvos-exposed mice displayed impairments in cognition, motor function, and mood along with disrupted inflammatory and antioxidant responses, neurotrophic factor levels, and acetylcholinesterase activity in brain and intestinal tissues. Weight loss and altered short-chain fatty acid levels additionally indicated gut dysfunction. However, intervention with tiger nut and/or coconut- enriched diet after dichlorvos exposure attenuated these neurobehavioral, and biochemical alterations. Our findings demonstrate organophosphate-induced communication disruptions between the gut and brain pathways that manifest in neuropsychiatric disturbances. Overall, incorporating fibre-rich nuts may represent an antidotal dietary strategy to reduce neurotoxicity and prevent brain disorders associated with organophosphate poisoning.

Molecular docking analysis of chlorpyrifos at the human α7-nAChR and its potential relationship with neurocytoxicity in SH-SY5Y cells

The organophosphate insecticide chlorpyrifos (CPF), an acetylcholinesterase inhibitor, has raised serious concerns about human safety. Apart from inducing synaptic acetylcholine accumulation, CPF could also act at nicotinic acetylcholine receptors, like the α7-isoform (α7-nAChR), which could potentially be harmful to developing brains. Our aims were to use molecular docking to assess the binding interactions between CPF and α7-nAChR through, to test the neurocytotoxic and oxidative effects of very low concentrations of CPF on SH-SY5Y cells, and to hypothesize about the potential mediation of α7-nAChR. Docking analysis showed a significant binding affinity of CPH for the E fragment of the α7-nAChR (ΔGibbs: -5.63 to -6.85 Kcal/mol). According to the MTT- and Trypan Blue-based viability assays, commercial CPF showed concentration- and time-dependent neurotoxic effects at a concentration range (2.5-20 µM), ten-folds lower than those reported to have crucial effects for sheer CPF. A rise of the production of radical oxygen species (ROS) was seen at even lower concentrations (1-2.5 µM) of CPF after 24h. Notably, our docking analysis supports the antagonistic actions of CPF on α7-nAChR that were recently published. In conclusion, while α7-nAChR is responsible for neuronal survival and neurodevelopmental processes, its activity may also mediate the neurotoxicity of CPF.

Harnessing the power of bacterial laccases for xenobiotic degradation in water: A 10-year overview

Industrialization and population growth are leading to the production of significant amounts of sewage containing hazardous xenobiotic compounds. These compounds pose a threat to human and animal health, as well as the overall ecosystem. To combat this issue, chemical, physical, and biological techniques have been used to remove these contaminants from water bodies affected by human activity. Biotechnological methods have proven effective in utilizing microorganisms and enzymes, particularly laccases, to address this problem. Laccases possess versatile enzymatic characteristics and have shown promise in degrading different xenobiotic compounds found in municipal, industrial, and medical wastewater. Both free enzymes and crude enzyme extracts have demonstrated success in the biotransformation of these compounds. Despite these advancements, the widespread use of laccases for bioremediation and wastewater treatment faces challenges due to the complex composition, high salt concentration, and extreme pH often present in contaminated media. These factors negatively impact protein stability, recovery, and recycling processes, hindering their large-scale application. These issues can be addressed by focusing on large-scale production, resolving operation problems, and utilizing cutting-edge genetic and protein engineering techniques. Additionally, finding novel sources of laccases, understanding their biochemical properties, enhancing their catalytic activity and thermostability, and improving their production processes are crucial steps towards overcoming these limitations. By doing so, enzyme-based biological degradation processes can be improved, resulting in more efficient removal of xenobiotics from water systems. This review summarizes the latest research on bacterial laccases over the past decade. It covers the advancements in identifying their structures, characterizing their biochemical properties, exploring their modes of action, and discovering their potential applications in the biotransformation and bioremediation of xenobiotic pollutants commonly present in water sources.

Machine learning and XAI approaches highlight the strong connection between O 3 and N O 2 pollutants and Alzheimer's disease

Alzheimer's disease (AD) is the most common type of dementia with millions of affected patients worldwide. Currently, there is still no cure and AD is often diagnosed long time after onset because there is no clear diagnosis. Thus, it is essential to study the physiology and pathogenesis of AD, investigating the risk factors that could be strongly connected to the disease onset. Despite AD, like other complex diseases, is the result of the combination of several factors, there is emerging agreement that environmental pollution should play a pivotal role in the causes of disease. In this work, we implemented an Artificial Intelligence model to predict AD mortality, expressed as Standardized Mortality Ratio, at Italian provincial level over 5 years. We employed a set of publicly available variables concerning pollution, health, society and economy to feed a Random Forest algorithm. Using methods based on eXplainable Artificial Intelligence (XAI) we found that air pollution (mainly O 3 and N O 2 ) contribute the most to AD mortality prediction. These results could help to shed light on the etiology of Alzheimer's disease and to confirm the urgent need to further investigate the relationship between the environment and the disease.

Implications of organophosphate pesticides on brain cells and their contribution toward progression of Alzheimer's disease

The most widespread neurodegenerative disorder, Alzheimer's disease (AD) is marked by severe behavioral abnormalities, cognitive and functional impairments. It is inextricably linked with the deposition of amyloid β (Aβ) plaques and tau protein in the brain. Loss of white matter, neurons, synapses, and reactive microgliosis are also frequently observed in patients of AD. Although the causative mechanisms behind the neuropathological alterations in AD are not fully understood, they are likely influenced by hereditary and environmental factors. The etiology and pathogenesis of AD are significantly influenced by the cells of the central nervous system, namely, glial cells and neurons, which are directly engaged in the transmission of electrical signals and the processing of information. Emerging evidence suggests that exposure to organophosphate pesticides (OPPs) can trigger inflammatory responses in glial cells, leading to various cascades of events that contribute to neuroinflammation, neuronal damage, and ultimately, AD pathogenesis. Furthermore, there are striking similarities between the biomarkers associated with AD and OPPs, including neuroinflammation, oxidative stress, dysregulation of microRNA, and accumulation of toxic protein aggregates, such as amyloid β. These shared markers suggest a potential mechanistic link between OPP exposure and AD pathology. In this review, we attempt to address the role of OPPs on altered cell physiology of the brain cells leading to neuroinflammation, mitochondrial dysfunction, and oxidative stress linked with AD pathogenesis.

Prevalence of Mild Cognitive Impairment in Southern Regions of Colombia

Background

Recent reports suggest that by 2050 there will be an increase of around 310% of cases affected by dementia in Latin American countries. A previous study in a Southern region reported one of the highest prevalences of dementia in Latin America.

Objective

To investigate the prevalence of mild cognitive impairment associated with low education, rurality, and demographic characteristics.

Methods

A cross-sectional study recruited a community-dwelling sample of 823 adults from rural and urban areas of two Southern provinces of Colombia from 2020-2022. Participants were assessed with a neuropsychological protocol validated in Colombia. To obtain general and region-specific prevalence rates, age, sex, schooling, and socioeconomic level were considered and controlled for.

Results

Most of the participants reported low education and socioeconomic level, the participation of women was higher. It was determined that the prevalence of mild cognitive impairment (MCI) was 53.6%, with 56.6% in the province of Caquetá followed by 51.9% in the province of Huila. The amnestic MCI represented 42.6%, the amnestic multi-domain was 39%, the non-amnestic 16.55%, and the non-amnestic multi-domain 1.81%. Our participants reported comorbidities such as diabetes and hypertension. We also observed a relationship between exposure to pesticides and MCI.

Conclusions

We observed one of the highest prevalences of MCI in Latin America reported to date. Variables such as age, gender, and education proved risk factors for MCI in the explored regions. Our findings are very much in line with recent studies that highlight the influence of non-canonical risk factors of dementia in underrepresented countries from Latin America.

Effect of pesticides on phosphorylation of tau protein, and its influence on Alzheimer's disease

Alzheimer's disease (AD) is a progressive and neurodegenerative illness which results in alterations in cognitive development. It is characterized by loss/dysfunction of cholinergic neurons, and formation of amyloid plaques, and formation of neurofibrillary tangles, among other changes, due to hyperphosphorylation of tau-protein. Exposure to pesticides in humans occurs frequently due to contact with contaminated food, water, or particles. Organochlorines, organophosphates, carbamates, pyrethroids and neonicotinoids are associated with the most diagnosed incidents of severe cognitive impairment. The aim of this study was to determine the effects of these pesticides on the phosphorylation of tau protein, and its cognitive implications in the development of AD. It was found that exposure to pesticides increased the phosphorylation of tau protein at sites Ser198, Ser199, Ser202, Thr205, Ser396 and Ser404. Contact with these chemicals altered the enzymatic activities of cyclin-dependent kinase 5 and glycogen synthase kinase 3 beta, and protein phosphatase-2A. Moreover, it altered the expression of the microtubule associated protein tau gene, and changed levels of intracellular calcium. These changes affected tau protein phosphorylation and neuroinflammation, and also increased oxidative stress. In addition, the exposed subjects had poor level of performance in tests that involved evaluation of novelty, as test on verbal, non-verbal, spatial memory, attention, and problem-solving skills.

The association between shift work exposure and cognitive impairment among middle-aged and older adults: Results from the Canadian Longitudinal Study on Aging (CLSA)

BACKGROUND

Shift work, especially rotating and night shift work, has been linked to a wide range of detrimental health outcomes. Occupational factors like shift work and their potential impact on cognitive functions have received little attention, and the evidence is inconclusive. The objective of our study is to explore associations between shift work exposure and cognitive impairment indicators based on comparisons with the normative standards from the Canadian population.

METHODS

Cross-sectional analyses were performed using baseline Canadian Longitudinal Study on Aging database, including 47,811 middle-aged and older adults (45-85 years). Three derived shift work variables were utilized: ever exposed to shift work, shift work exposure in longest job, and shift work exposure in current job. Four cognitive function tests were utilized, Rey Auditory Verbal Learning Tests (immediate and delayed) representing memory domain, and Animal Fluency, and Mental Alteration, representing the executive function domain. All cognitive test scores included in study were normalized and adjusted for the participant's age, sex, education and language of test administration (English and French), which were then compared to normative data to create "cognitive impairment' variables. Unadjusted and adjusted multivariable logistic regression models were used to determine associations between shift work variables and cognitive impairment individually (memory and executive function domains), and also for overall cognitive impairment.

RESULT

Overall, one in every five individuals (21%) reported having been exposed to some kind of shift work during their jobs. Exposure to night shift work (both current and longest job) was associated with overall cognitive impairment. In terms of domain-based measures, night shift work (longest job) was associated with memory function impairment, and those exposed to rotating shift work (both current and longest job) showed impairment on executive function measures, when compared to daytime workers.

CONCLUSION

This study suggests disruption to the circadian rhythm, due to shift work has negative impact on cognitive function in middle-aged and older adults and this warrants further investigation.

Brain-targeted nanoreactors prevent the development of organophosphate-induced delayed neurological damage

BACKGROUND

Organophosphate (OP)-induced delayed neurological damage is attributed to permanent neuropathological lesions caused by irreversible OP-neurocyte interactions, without potent brain-targeted etiological antidotes to date. The development of alternative therapies to achieve intracerebral OP detoxification is urgently needed.

METHODS

We designed a brain-targeted nanoreactor by integrating enzyme immobilization and biomimetic membrane camouflaging protocols with careful characterization, and then examined its blood-brain barrier (BBB) permeability both in vitro and in vivo. Subsequently, the oxidative stress parameters, neuroinflammatory factors, apoptotic proteins and histopathological changes were measured and neurobehavioral tests were performed.

RESULTS

The well-characterized nanoreactors exerted favourable BBB penetration capability both in vitro and in vivo, significantly inhibiting OP-induced intracerebral damage. At the cellular and tissue levels, nanoreactors obviously blocked oxidative stress, cellular apoptosis, inflammatory reactions and brain histopathological damage. Furthermore, nanoreactors radically prevented the occurrence of OP-induced delayed cognitive deficits and psychiatric abnormality.

CONCLUSION

The nanoreactors significantly prevented the development of OP-induced delayed neurological damage, suggesting a potential brain-targeted etiological strategy to attenuate OP-related delayed neurological and neurobehavioral disorders.

Overhauling the ecotoxicological impact of synthetic pesticides using plants' natural products: a focus on Zanthoxylum metabolites

The reduction in agricultural production due to the negative impact of insects and weeds, as well as the health and economic burden associated with vector-borne diseases, has promoted the wide use of chemicals that control these "enemies." However, the use of these synthetic chemicals has been recognized to elicit negative impacts on the environment as well as the health and wellbeing of man. In this study, we presented an overview of recent updates on the environmental and health impacts of synthetic pesticides against agro-pest and disease vectors while exhaustive reviewing the potentials of natural plant products from Zanthoxylum species (Rutaceae) as sustainable alternatives. This study is expected to spur further research on exploiting these plants and their chemicals as safe and effective pesticide entities to minimize the impact of their chemical and synthetic counterparts on health and the environment.

The status and natural impact of floriculture production in Ethiopia: a systematic review

Ethiopia's floriculture industry is exceedingly emerging, and, currently, it ranks as the sixth largest exporter of roses worldwide and second largest in Africa. Currently, many flowers, such as rose, gypsophila, carnations, and chrysanthemum, are growing. However, floriculture farms are contributing a high level of health risks and environmental problems in Ethiopia. Thus, the purpose of this paper is to scrutinize the status and impacts of floriculture industries in Ethiopia. The floriculture division is an emerging sector in Ethiopia, and the number of farms, income, job opportunities, and diversity of flowers are increasing. However, the health risks and environmental fates of the sector are also increasing. Ethiopian floriculture farms lack waste disposal technologies and workers' protective equipment and safety, and the chemicals, plastics, and corrugated irons used in the farms are carelessly disposed everywhere. Pesticides, plastics, and fertilizers are also freely discharged into water bodies and terrestrial land, which is causing the development of health risks; aquatic life hazards; and soil, water, and air pollution. However, Ethiopia has no strong and functional system or structure to control the impacts of floriculture farms. The government and the farm owners are not thoughtful about the environmental issues, health concerns, and socioeconomic impacts of the wastes. The government lacks regular control and assessment of farms, and the farms are engaging for their profit. Nevertheless, developed countries are currently using both natural and modern technologies to manage floricultural wastes. Ethiopia should therefore suggest manageable possible approaches and sound management strategies based on the findings of the analyses.