Cholinesterase Activity Research Articles

Biomarkers of Pesticide Exposure in a Traditional Brazilian Amazon Community

In 2008, Brazil became the country with the highest pesticide use in the world, with over one billion liters of pesticides applied to crops in 2009. The impacts of these products on public health are wide-ranging. Vast territories are affected, involving different population groups, such as workers in various fields of activity, the population that consumes contaminated food, and people living around factories, such as traditional communities. This study aimed to assess human exposure to pesticides through epidemiological and laboratory data of residents of the Santo Antônio quilombola community in Concórdia do Pará, Amazon region, Brazil. Epidemiological data were collected using a semi-structured questionnaire, which included factors such as sex, age, length of residence, and level of exposure to pesticides. The modified Ellman method was used to assess the activity of cholinesterases, and flow cytometry was performed for cytokine analysis. Analysis of collected blood samples showed that, in most cases, there was no significant reduction in the activity of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) compared to other studies in the scientific literature. Meanwhile, there was an increase in the levels of IFN-γ cytokines, especially IL-6, in all groups. The findings of this study highlight the urgent need for a comprehensive monitoring program, considering that some conditions other than pesticide exposure can alter the activities of the biomarkers used in this study.

Assessing the Potential of 1,2,3-Triazole-Dihydropyrimidinone Hybrids Against Cholinesterases: In Silico, In Vitro, and In Vivo Studies.

Combining the pharmacological properties of the 1,2,3-triazole and dihydropyrimidinone classes of compounds, two small families of mono- and di(1,2,3-triazole)-dihydropyrimidinone hybrids, A and B, were previously synthesized. The main objective of this work was to investigate the potential anti-Alzheimer effects of these hybrids. The inhibitory activities of cholinesterases (AChE and BuChE), antioxidant activity, and the inhibitory mechanism through in silico (molecular docking) and in solution (STD-NMR) experiments were evaluated. The 1,2,3-triazole-dihydropyrimidinone hybrids (A and B) showed moderate in vitro inhibitory activity on eqBuChE (IC50 values between 1 and 58.4 μM). The best inhibitor was the hybrid B4, featuring two 1,2,3-triazole cores, which exhibited stronger inhibition than galantamine, with an IC50 of 1 ± 0.1 μM for eqBuChE, through a mixed inhibition mechanism. Among the hybrids A, the most promising inhibitor was A1, exhibiting an IC50 of 12 ± 2 µM, similar to that of galantamine. Molecular docking and STD-NMR experiments revealed the key binding interactions of these promising inhibitors with BuChE. Hybrids A and B did not display Artemia salina toxicity below 100 μM.

Glycosylation of chrysin with β-d-glucose tetraacetate (LQFM280) enhances its in vitro and in vivo neuroprotective effects against the toxicity induced by 3-nitropropionic acid.

Chrysin (CHR) is a naturally occurring flavonoid found in the human diet, recognized for its potential in preventing neurodegenerative diseases. However, its limited water solubility restricts its bioavailability and therapeutic applications. To address this issue and bolster the neuroprotective properties of CHR for potential nutraceutical or medicinal use, we investigated a novel compound, LQFM280, formed by conjugating CHR with β-d-glucose tetraacetate. We conducted both in vitro (using SH-SY5Y cells, mutant STHdhQ111/Q111 cells, and wild-type STHdhQ7/Q7 cells), and in vivo (mice) neurotoxicity experimental model induced by 3-nitropropionic acid, which mimic biological changes akin to Huntington's disease in humans. Compared to non-glycosylated CHR, LQFM280 showed superior in vitro effects in preventing neurotoxicity caused by increased mitochondrial vulnerability due to mutant huntingtin. In vivo findings demonstrated that LQFM280 has heightened efficacy in mitigating weight loss, memory and locomotor impairment, oxidative stress, and disruptions in the antioxidant defense system, as well as succinate dehydrogenase, and cholinesterase activities induced by 3-nitropropionic acid. These findings underscore the significant enhancement of chrysin's neuroprotective effects through glycosylation with β-d-glucose tetraacetate, positioning it as a promising candidate for use as a nutraceutical or food supplement to promote health benefits.

Screening and Optimization of Pathogenic Strains of Pseudomonas sp. for Cholinesterase Enzyme Activity

The identification and optimization of pathogenic strains of Pseudomonas sp. with significant Cholinesterase enzyme activity has promising implications for environmental and medical applications. This study aimed to screen various Pseudomonas strains to identify those exhibiting high cholinesterase activity and to optimize the conditions for maximal enzyme production. Multiple Pseudomonas strains were isolated and characterized from diverse clinical samples, employing selective media and biochemical assays to determine cholinesterase activity. The strains with maximum enzyme activity were further subjected to optimization experiments, including variations in growth conditions such as Temperature, pH and Nutrient availability. The findings revealed sample no.39 among the collected 50 samples had significant enzyme activity of 0.19151 IU is obtained when choline chloride was 0.3999%, Ammonium Chloride was 0.01M, pH was 7.0, Temperature was 27°C and Time of incubation was 24hrs. These results not only advance our understanding of Pseudomonas sp. enzyme capabilities but also offer potential applications in bioremediation, biosensor development and pharmaceutical industries. Future research will focus on the molecular characterization of the cholinesterase enzyme and its applications in various industrial processes.

Does temperature influence on biomarker responses to copper exposure? The invasive bivalve Limnoperna fortunei (Dunker 1857) as a model

Biomarkers are useful tools for assessing the early warning effects of pollutants. However, their responses can be influenced by confounding factors. In this study, we investigated the influence of temperature on multiple biomarkers in the invasive freshwater bivalve Limnoperna fortunei exposed to copper (Cu). The mussels were exposed to low and high environmental Cu concentrations at two temperatures (15 °C and 25 °C). After 96 h, the oxidative stress, neurotoxicity, and metabolic parameters were assessed. Our results showed that temperature is a key factor influencing biomarker responses in mussels, with higher glutathione S-transferase activity and lower energy reserves at cold temperature. In addition, the effects of Cu were greater at the highest concentration at 15 °C (increased lipid peroxidation and cholinesterase activity). Overall, these findings suggest that cold stress increases the susceptibility of L. fortunei to metal effects and highlight the importance of including temperature in toxicity testing and biomonitoring. In addition, using the invasive bivalve L. fortunei as a model could prove valuable in its role as a sentinel species for other organisms.

Neuroprotective effects of punicalagin and/or micronized zeolite clinoptilolite on manganese-induced Parkinson's disease in a rat model: Involvement of multiple pathways.

Manganism, a central nervous system dysfunction correlated with neurological deficits such as Parkinsonism, is caused by the substantial collection of manganese chloride (MnCl2) in the brain. To explore the neuroprotective effects of natural compounds, namely, micronized zeolite clinoptilolite (ZC) and punicalagin (PUN), either individually or in combination, against MnCl2-induced Parkinson's disease (PD). Fifty male albino rats were divided into 5 groups (Gps). Gp I was used as the control group, and the remaining animals received MnCl2 (Gp II-Gp V). Rats in Gps III and IV were treated with ZC and PUN, respectively. Gp V received both ZC and PUN as previously reported for the solo-treated plants. ZC and/or PUN reversed the depletion of monoamines in the brain and decreased acetyl choline esterase activity, which primarily adjusted the animals' behavior and motor coordination. ZC and PUN restored the balance between glutamate/γ-amino butyric acid content and markedly improved the brain levels of brain-derived neurotrophic factor and nuclear factor erythroid 2-related factor 2/heme oxygenase-1 and decreased glycogen synthase kinase-3 beta activity. ZC and PUN also inhibited inflammatory and oxidative markers, including nuclear factor kappa-light-chain-enhancer of activated B cells, Toll-like receptor 4, nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3 and caspase-1. Bcl-2-associated X-protein and B-cell leukemia/lymphoma 2 protein (Bcl-2) can significantly modify caspase-3 expression. ZC and/or PUN ameliorated PD in rats by decreasing the levels of endoplasmic reticulum (ER) stress markers (p-protein kinase-like ER kinase (PERK), glucose-regulated protein 78, and C/EBP homologous protein (CHOP)) and enhancing the levels of an autophagy marker (Beclin-1). ZC and/or PUN mitigated the progression of PD through their potential neurotrophic, neurogenic, anti-inflammatory, antioxidant, and anti-apoptotic activities and by controlling ER stress through modulation of the PERK/CHOP/Bcl-2 pathway.

Biomarker responses in fish caged in a rice field during a bifenthrin application

The use of pesticides in integrated rice-fish farming could have an impact on fish health. The present study aimed to evaluate, for the first time, the biological effects of the insecticide bifenthrin on fish (Piaractus mesopotamicus and Hoplosternum littorale) using a caging experiment. Fish were divided into two sites: control (C) and bifenthrin exposure (BF). Two cages (n = 8 fish/cage) per species were placed separately at each site. The BF application (Seizer ®) was carried out with a coastal sprayer according to the BF recommended dose for rice cultivation (0.1 L/ha). After 72 hours, fish were collected, and gills, liver, brain, and muscle were dissected for the analysis of biomarkers of accumulation, oxidative stress, and neurotoxicity. In P. mesopotamicus, the main changes were observed in the muscle, where BF accumulated and induced neurotoxicity (inhibition of cholinesterase activity) and oxidative stress (activation of antioxidant enzymes, decreased glutathione levels, increased lipid peroxidation). The gills and liver also showed changes in some markers of the antioxidant system. In H. littorale, BF exposure induced changes in oxidative stress biomarkers in liver (activation of antioxidant enzymes and lipid peroxidation) and gill tissues (alteration in antioxidant markers). These results show that the use of bifenthrin in rice fields poses a risk to fish farming under current pesticide management practices. Furthermore, its use could affect other species in these agroecosystems, highlighting the need for further studies to assess the ecological and productive consequences in a context of increasing pyrethroid use worldwide.

Enhanced Recognition Memory through Dual Modulation of Brain Carbonic Anhydrases and Cholinesterases.

This study introduces a novel multitargeting strategy that combines carbonic anhydrase (CA) activators and cholinesterase (ChE) inhibitors to enhance cognitive functions. A series of tacrine-based derivatives with amine/amino acid moieties were synthesized and evaluated for their dual activity on brain CA isoforms and ChEs (AChE and BChE). Several derivatives, notably compounds 26, 30, 34, and 40, demonstrated potent CA activation, particularly of hCA II and VII, and strong ChE inhibition with subnanomolar to low nanomolar IC50 values. In vivo studies using a mouse model of social recognition memory showed that these derivatives significantly improved memory consolidation at doses 10-100 times lower than the reference compounds (either alone or in combination). Molecular modeling and ADMET predictions elucidated the compound binding modes and confirmed favorable pharmacokinetic and safety profiles. The findings suggest that dual modulation of CA and ChE activities is a promising strategy for treating cognitive deficits associated with neurodegenerative and psychiatric disorders.

Biomarkers and metal content in white seabream (Diplodus sargus) and its relationship with the occurrence of the Abnormal Tough Syndrome

There is still controversy on the cause of the incidence of abnormal tough syndrome (ATS) in some fish species, mainly the white seabream (Diplodus sargus). This work analyses the incidence of the ATS in white seabream in areas with a different extent of heavy metal pollution and its possible relationship with fish health. Muscular cholinesterase (ChE) activities were selected to assess their potential as biomarkers of ATS occurrence. Among the trace elements Zn, Cu, Pb, and As in muscle and Cu in liver were significantly higher in the fish from the most polluted marina location. ATS incidence (33 %) was also recorded in this site with individuals showing a significantly lower body condition but ChE activities did not reflect any neurotoxic impact on the fish, neither did detoxification and oxidative stress damage. However, a significant negative association was seen between AChE activity and muscle body burden of Hg, Cu, and Se in fish from the less impacted sites, which suggests a certain neurotoxic modulation by these metals. It also alerts for the consumption of fish from recreational activities that do not follow any regulatory measures.

The medicinal plant Buddleja asiatica and its relation to the welfare of local people in the Pan‐Himalayan region: Past, present, and future perspectives

Societal Impact StatementGlobalization and rapid shifts in culture and economy threaten indigenous and local knowledge (ILK) systems, and large intergenerational gaps in this knowledge already exist. Buddleja asiatica is a deciduous shrub or small tree with traditional medicinal applications but is currently largely overlooked as a medicinal resource. This study investigates the traditional uses of B. asiatica in indigenous communities in the Pan‐Himalayan region through ethnobotanical field surveys, with a view to preserving cultural heritage and strengthening economic resilience in these communities, as well as developing B. asiatica as a medicinal resource. Prioritizing the well‐being of mountain communities, this study aims to bridge community development with nature.SummaryBuddleja asiatica Lour. (Scrophulariaceae) is widely distributed across the Pan‐Himalayan region. It has traditional medicinal applications and cultural value, as well as ecological significance. We conducted an ethnobotanical study combining field surveys from Nepal and Xizang, China with a literature review using Web of Science (WoS) to review the ethnobotanical, phytochemical, and pharmacological aspects of this species. Our study highlights the cultural significance of B. asiatica within indigenous communities and, in particular, the use of the leaves to make a starter culture for the preparation of wine. However, an evident intergenerational gap in knowledge transfer exists. The phytochemical investigation revealed the presence of various chemical classes (carbohydrates, terpenoids, flavonoids, saponins, esters, steroids, glycosides, and fatty acids), of which 15 phytoconstituents were first reported from various parts of B. asiatica. The potential medicinal properties of these chemicals include anti‐inflammatory, antioxidant, cytotoxic, antihepatotoxic, antimicrobial, and cholinesterase activities. We combine these lines of evidence to show the prospects for the livelihoods of local people across this region and propose future research directions.

Inhibitory Effects of Aspirin and Ibuprofen Overdose on Cholinesterase Activity: In Vivo and In Vitro Studies.

In recent years, it has been reported that long-term use of Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) may have protective effects against neurodegenerative diseases by inhibiting the activity of cholinesterase enzymes. The exact biological mechanism of these protective effects is not yet known. This study aims to assess the in vivo and in vitro effects of aspirin and ibuprofen injection on the activity of acetylcholinesterase and butyrylcholinesterase. In this experimental study, 70 adult male mice (20-25 g) were divided randomly into 7 groups (n= 10) including a control group that received normal saline and other groups that received different dosages of aspirin and ibuprofen (100, 200, and 300 mg/kg) in the form of intraperitoneal injection. Mice were anesthetized by ether, and blood samples were taken from the heart. Ellman´s methods were used to measure cholinesterase, erythrocytes, and serum, respectively. The activity of cholinesterase enzymes in serum and erythrocytes decreased significantly (P<0.0001) in treated groups with aspirin and ibuprofen compared to the control samples after 3 and 24 hours. However, these inhibitory effects were variable depending on the dose of the injected drugs, and they were statistically significant at higher injection doses in vitro and in vivo analysis. The result of this study showed that non-steroidal anti-inflammatory drugs can inhibit the activity of the cholinesterase enzymes in both in vivo and in vitro conditions compared to the control group.

A short-term exposure to saxitoxin triggers a multitude of deleterious effects in Daphnia magna at levels deemed safe for human health

Harmful algal blooms and the toxins produced during these events are a human and environmental health concern worldwide. Saxitoxin and its derivatives are potent natural aquatic neurotoxins produced by certain freshwater cyanobacteria and marine algae species during these bloom events. Saxitoxins effects on human health are well studied, however its effects on aquatic biota are still largely unexplored. This work aims at evaluating the effects of a pulse acute exposure (24 h) of the model cladoceran Daphnia magna to 30 μg saxitoxin L−1, which corresponds to the safety guideline established by the World Health Organization (WHO) for these toxins in recreational freshwaters. Saxitoxin effects were assessed through a comprehensive array of biochemical (antioxidant enzymes activity and lipid peroxidation), genotoxicity (alkaline comet assay), neurotoxicity (total cholinesterases activity), behavioral (swimming patterns), physiological (feeding rate and heart rate), and epigenetic (total 5-mC DNA methylation) biomarkers. Exposure resulted in decreased feeding rate, heart rate, total cholinesterases activity and catalase activity. Contrarily, other antioxidant enzymes, namely glutathione-S-transferases and selenium-dependent Glutathione peroxidase had their activity increased, together with lipid peroxidation levels. The enhancement of the antioxidant enzymes was not sufficient to prevent oxidative damage, as underpinned by lipid peroxidation enhancement. Accordingly, average DNA damage level was significantly increased in STX-exposed daphnids. Total DNA 5-mC level was significantly decreased in exposed organisms. Results showed that even a short-term exposure to saxitoxin causes significant effects on critical molecular and cellular pathways and modulates swimming patterns in D. magna individuals. This study highlights sub-lethal effects caused by saxitoxin in D. magna, suggesting that these toxins may represent a marked challenge to their thriving even at a concentration deemed safe for humans by the WHO.

Optimization of bioactivities of solvent extracts of bark and heartwood of Pterocarpus marsupium and exploration of neuroprotective effect linking to the major Phytoconstituents

The study aims to evaluate the neuroprotective properties of Pterocarpus marsupium Roxb. The bioactive optimized hydroalcohol-extracted fractions of bark (PMBHA) and heartwood (PMHHA) at 300 and 400 mg/kg were examined in rats with scopolamine-induced neurotoxicity to study oxidative, neurochemical, and neuroinflammation biomarkers. Phenol and flavonoid-rich radical scavengers in contributing total antioxidant capacities of PMBHA and PMHHA quenched peroxyl radicals and protected the cellular membrane and lipoproteins from ROS in DPPH, ORAC, and CAP-e tests. In anticholinesterase activities, PMBHA inhibited AChE (IC50: 54.40 ± 0.98 µg/mL) and BChE (IC50: 50.95 ± 0.98 µg/mL) mixed-competitively, while PMHHA inhibited cholinesterase activities (AChE: 42.23 ± 0.54, and BChE: 47.19 ± 0.65 µg/mL) competitively. Dosage at 300 and 400 mg/kg of PMBHA and PMHHA improved serum and brain oxidative indicators (MDA, SOD, CAT, and GSH), and restored proinflammatory cytokines (TNF-α, and IL-6) leading to enhanced brain cholinesterase and β-secretase levels in neurotoxic rats. GC-MS reported antioxidant, anti-inflammatory, and neuroprotective compounds of PMBHA catechol, thiamet-G, d-Gala-l-ido-octonic amide, falcarinol, D-mannose, ribitol, 1,2,4-cyclopentanetrione, 3-(2-pentenyl)-, hexadecanoic acid methyl ester, n-hexadecanoic acid, oleic acid, and 3,5-Dimethoxybenzyl alcohol, α-epi-7-epi-5-Eudesmol, 1 R,4aR,7 R,8aR)-7-(2-Hydroxypropan-2-yl)-1,4a-dimethyldecahydro naphthalen-1-ol, arctiol, 1,1,4,7-tetramethyldecahydro-1 H-cyclopropa[e]azulene-4,7-diol, 2-Propen-1-ol, 3-(2,6,6-trimethyl-1-cyclohexen-1-yl), 4-t-Butyl-2-[4-nitrophenyl]phenol in PMHHA were responsible in neuroprotection in neurotoxic rats. However, heartwood demonstrated better neuroprotective activities than the bark of P. marsupium due to some of the key compounds (1 R,4aR,7 R,8aR)-7-(2-Hydroxypropan-2-yl)-1,4a-dimethyldecahydronaphthalen-1-ol, 2-Propen-1-ol, 3-(2,6,6-trimethyl-1-cyclohexen-1-yl)-, 4-t-Butyl-2-[4-nitrophenyl]phenol, 1,1,4,7-Tetramethyldecahydro-1 H-cyclopropa[e]azulene-4,7-diol.

Effects of Dietary Chitosan on Growth Performance, Serum Biochemical Indices, Antioxidant Capacity, and Immune Response of Juvenile Tilapia (Oreochromis niloticus) under Cadmium Stress.

The objective of this study was to examine the effects of varying levels of dietary chitosan supplementation on mitigating cadmium stress and its influence on growth performance, serum biochemical indices, antioxidant capacity, immune response, inflammatory response, and the expression of related genes in juvenile Genetically Improved Farmed Tilapia (GIFT, Oreochromis niloticus). Five groups of juvenile tilapias (initial body weight 21.21 ± 0.24 g) were fed five diets with different levels (0%, 0.5%, 1.0%, 1.5%, and 2.0%) of chitosan supplementation for 60 days under cadmium stress (0.2 mg/L Cd2+). The findings indicated that, compared with the 0% chitosan group, dietary chitosan could significantly increase (p < 0.05) the final weight (Wf), weight gain rate (WGR), specific growth rate (SGR), daily growth index (DGI), and condition factor (CF), while the feed conversion ratio (FCR) expressed the opposite trend in juvenile GIFT. Dietary chitosan could significantly increase (p < 0.05) the activities (contents) of cholinesterase (CHE), albumin (ALB), lactate dehydrogenase (LDH), alkaline phosphatase (ALP), acid phosphatase (ACP), and lysozyme (LZM), while glutamic pyruvic transaminase (GPT), glutamic oxaloacetic transaminase (GOT), and complement 3 (C3) in the serum of juvenile GIFT expressed the opposite trend. Dietary chitosan could significantly increase (p < 0.05) the activities of superoxide dismutase (SOD) and catalase (CAT) and significantly decrease (p < 0.05) the activities (contents) of glutathione S-transferase (GST), glutathione peroxidase (GSH-Px), and malondialdehyde (MDA) in the serum of juvenile GIFT. Dietary chitosan could significantly increase (p < 0.05) the activities (contents) of CAT, GST, GSH-Px, and total antioxidant capacity (T-AOC) and significantly decrease (p < 0.05) the contents of MDA in the liver of juvenile GIFT. Dietary chitosan could significantly increase (p < 0.05) the activities (contents) of SOD, GSH-Px, T-AOC, Na+-K+-ATPase, and Ca2+-ATPase and significantly decrease (p < 0.05) the activities (contents) of CAT, GST, and MDA in the gills of juvenile GIFT. Dietary chitosan could significantly up-regulate (p < 0.05) the gene expression of cat, sod, gst, and gsh-px in the liver of juvenile GIFT. Dietary chitosan could significantly up-regulate (p < 0.05) the gene expression of interferon-γ (inf-γ) in the gills and spleen and significantly down-regulate (p < 0.05) the gene expression of inf-γ in the liver and head kidney of juvenile GIFT. Dietary chitosan could significantly down-regulate (p < 0.05) the gene expression of interleukin-6 (il-6), il-8, and tumor necrosis factor-α (tnf-α) in the liver, gills, head kidney, and spleen of juvenile GIFT. Dietary chitosan could significantly up-regulate (p < 0.05) the gene expression of il-10 in the liver, gills, head kidney, and spleen of juvenile GIFT. Dietary chitosan could significantly up-regulate (p < 0.05) the gene expression of transforming growth factor-β (tgf-β) in the liver and significantly down-regulate (p < 0.05) the gene expression of tgf-β in the head kidney and spleen of juvenile GIFT. In conclusion, dietary chitosan could mitigate the impact of cadmium stress on growth performance, serum biochemical indices, antioxidant capacity, immune response, inflammatory response, and related gene expression in juvenile GIFT. According to the analysis of second-order polynomial regression, it was found that the optimal dietary chitosan levels in juvenile GIFT was approximately 1.42% to 1.45%, based on its impact on Wf, WGR, SGR, and DGI.

Design, synthesis, molecular modeling, in vitro evaluation of novel piperidine-containing hydrazone derivatives as cholinesterase inhibitors.

In an effort to develop new and effective therapeutic agents for Alzheimer's disease, a series of hydrazone derivatives bearing piperidine rings have been designed and synthesized. The chemical structures of the compounds were characterized by various spectroscopic techniques. In vitro antioxidant and cholinesterase activities of the compounds were evaluated. Among the compounds, N12 exhibited the most antioxidant activity in all methods (CUPRAC, FRAP, DPPH, ABTS). In vitro acetylcholinesterase (AChE) activity results of the compounds showed good IC50 values between 14.124 ± 0.084 and 49.680 ± 0.110 µM were obtained (IC50 = 38.842 ± 0.053 µM for Donepezil). Among the compounds, N7 and N6 are much more effective derivatives than the standard compound donepezil with IC50 values of 14.124 ± 0.084 and 17.968 ± 0.072 µM, respectively. In vitro, butyrylcholinesterase (BChE) inhibition values of the compounds were between 13.505 ± 0.025 and 52.230 ± 0.027 μm. Among the compounds, N6 has the highest BChE inhibition with an IC50 value of 13.505 μm in the series. The cytotoxicity and AChE inhibitory activity of the compounds on SH-SY5Y cell lines were also evaluated. Kinetic studies were also performed to determine the behavior of the compounds as competitive or noncompetitive inhibitors. The binding modes of N6, which was determined to be highly effective according to in vitro analyses, with AChE and BChE were investigated using molecular docking studies, and the stability of the complexes was determined by molecular dynamics simulations. These findings indicated that AChE and BChE enzymes maintained their overall structural stability and compactness during interactions with compound N6.

Effect of curcumin-donepezil combination on spatial memory, astrocyte activation, and cholinesterase expressions in brain of scopolamine-treated rats.

The study investigated the effect of co-administration of curcumin and donepezil on several markers of cognitive function (such as spatial memory, astrocyte activation, cholinesterase expressions) in the brain cortex and hippocampus of scopolamine-treated rats. For seven consecutive days, a pre-treatment of curcumin (50mg/kg) and/or donepezil (2.5mg/kg) was administered. On the seventh day, scopolamine (1mg/kg) was administered to elicit cognitive impairment, 30min before memory test was conducted. This was followed by evaluating changes in spatial memory, cholinesterase, and adenosine deaminase (ADA) activities, as well as nitric oxide (NO) level were determined. Additionally, RT-qPCR for glial fibrillary acidic protein (GFAP) and cholinesterase gene expressions was performed in the brain cortex and hippocampus. Also, GFAP immunohistochemistry of the brain tissues for neuronal injury were performed in the brain cortex and hippocampus. In comparison to the control group, rats given scopolamine had impaired memory, higher levels of acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and ADA activities, as well as elevated markers of oxidative stress. In addition to enhanced GFAP immunoreactivity, there was also overexpression of the GFAP and BChE genes in the brain tissues. The combination of curcumin and donepezil was, however, observed tobetter ameliorate these impairments in comparison to thedonepezil-administered rat group. Hence, this evidence provides more mechanisms to support the hypothesis that the concurrent administration of curcumin and donepezil mitigates markers of cognitive dysfunction in scopolamine-treated rat model.

Near-infrared fluorescent probe for ultrasensitive detection of organophosphorus pesticides and visualization of their interaction with butyrylcholinesterase in living cells

The toxicity of organophosphorus pesticides (OPs) can catastrophically cause liver cell damage and inhibit the catalytic activity of cholinesterase. We designed and synthesized a near-infrared fluorescent probe HP-LZB with large Stokes shift which can specifically identify and detect butyrylcholinesterase (BChE) and visually explore the interaction between OPs and endogenous BChE in living cells. Fluorescence was turned on when HP-LZB was hydrolyzed into HP-LZ in the presence of BChE, and OPs could inhibit BChE's activity resulting in a decrease of fluorescence. Six OPs including three oxon pesticides (paraoxon, chlorpyrifos oxon and diazoxon) and their corresponding thion pesticides (parathion, chlorpyrifos and diazinon) were investigated. Both in vitro and cell experiments indicated that only oxon pesticides could inhibit BChE's activity. The limits of detection (LODs) of paraoxon, chlorpyrifos oxon and diazoxon were as low as 0.295, 0.007 and 0.011 ng mL−1 respectively and the recovery of OPs residue in vegetable samples was satisfactory. Thion pesticides themselves could hardly inhibit the activity of BChE and are only toxic when they are converted to their corresponding oxon form in the metabolic process. However, in this work, thion pesticides were found not be oxidized into their oxon forms in living HepG2 cells due to the lack of cytochrome P450 in hepatoma HepG2 cell lines. Therefore, this probe has great application potential in effectively monitoring OPs in real plant samples and visually exploring the interaction between OPs and BChE in living cells.

Evaluation of genotoxic effects in workers and residents of rural areas exposed to pesticides in Brazil

Brazil is one of the world’s largest consumers of pesticides. This intense use impacts the environment and exposes a wide range of individuals to pesticides, including rural workers who are occupationally exposed and rural residents who are environmentally exposed. We aimed to evaluate the effects of occupational exposure to pesticides on the health of rural workers and rural residents. We conducted an epidemiological study with 104 farmers and 23 rural residents of Casimiro de Abreu (Rio de Janeiro, Brazil). A comparison group (urban residents) comprised 103 residents of the urban area of the same city. We determined the activity of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) using a modified version of Ellman’s method to evaluate exposure. In addition, we performed genotoxic and mutagenic analyses with the comet assay and the cytokinesis-block micronucleus (CBMN) assay. There was a reduction in cholinesterase activity, mainly BChE, in rural workers and rural residents compared with urban residents (p = 0.002). There was an increase in genotoxic effects in rural workers compared with urban residents (comet assay, p < 0.001; CBMN assay, p < 0.001). In addition, there was a greater chance of genotoxic changes in rural workers exposed to pesticides based on the comet assay (odds ratio [OR] 7.6, 95 % confidence interval [CI] 6.6–15.9) and the CBMN assay (OR 22.7, 95 % CI 10.3–49.9). We found that individuals occupationally exposed to pesticides are more likely to have genotoxic effects. These findings are useful for the development of programs to monitor populations exposed to genotoxic substances and allow the development of strategies for the prevention, control, and surveillance of effects that result from occupational and environmental exposures to pesticides.

Chemical characterization and biological properties of oyster and shiitake mushrooms extracts and their liposomal formulations

In recent years, the production of liposomal formulations using mushroom extracts has gained increasing interest to increase the bioavailability of bioactive compounds in the nutraceutical field. Based on this information, we aimed to determine the antioxidant capacity (by DPPH, ABTS, CUPRAC and FRAP assays) and enzyme inhibition (against cholinesterase, amylase, glucosidase and tyrosinase) activities of alone and liposomal formulations of Pleurotusostreatus (OYE) or Lentinusedodes (SHE) in different extracts solvents which were methanol (MeOH), aqua (Aq), methanol/aqua (MeOH/Aq). The extracts and formulations were chemically characterized using HPLC-DAD. The mean diameter of SL:SHE and SL:OYE (in MeOH/Aq) extended in range between 60 and 165 nm. The entrapment yields of SL:SHE and SL:OYE (in MeOH/Aq) were 63.8% ± 3.7% and 71.2% ± 2.8%, respectively. HPLC-DAD analysis revealed that ferulic and cinnamic acids were main components in the liposomal formulations. Liposomal formulations (in MeOH) showed higher antioxidant activity in the FRAP and CUPRAC assays. SL:SHE (in Aq) showed effective enzyme inhibition activity on acetylcholinesterase, tyrosinase, amylase and glucosidase enzymes. Based on our findings, the liposomal formulations can be a valuable strategy in preparing functional applications with shiitake and oyster mushrooms.

Investigation of cholinesterase and α-glucosidase enzyme activities, and molecular docking and dft studies for 1,2-disubstituted cyclopentane derivatives with phenyl and benzyl units.

Six known products (4-9) were prepared from reaction of adipoyl chloride with 1,2,3-trimethoxybenzene according to the literature. From (2,3,4-trimethoxyphenyl)(2-(2,3,4-trimethoxyphenyl)cyclopent-1-en-1-yl)methanone (4) of them, four new 1,2-disubstituted cyclopentane derivatives (10-13) with phenyl and benzyl units were synthesized by reactions such as hydrazonation, catalytic hydrogenation and bromination. The obtained compounds 4-13 were examined for their in vitro inhibitory activity against acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and α-glucosidase enzymes. All compounds 4-13 showed inhibition at nanomolar level with Ki values in the range of 45.53 ± 7.35-631.96 ± 18.88nM for AChE, 84.30 ± 9.92-622.10 ± 35.14nM for BChE, and 25.47 ± 4.46-48.87 ± 7.33 for α-Glu. In silico molecular docking studies of the potent compounds were performed in the active sites of AChE (PDB: 1E66), BChE (PDB: 1P0I), and α-glucosidase (PDB: 5ZCC) to compare the effect of bromine atom on the inhibition mechanism. The optimized molecular structures, HOMO-LUMO energies and molecular electrostatic potential maps for the compounds were calculated by using density functional theory with B3LYP/6-31 + G(d,p).