Acetylcholinesterase Concentration Research Articles

Effect of thiamethoxam on the behavioral profile alteration and toxicity of adult zebrafish at environmentally relevant concentrations

Thiamethoxam (THM) is a commercial neonicotinoid insecticide with broad-spectrum insecticidal activity. It has been widely detected in the aquatic environment, but its behavioral toxicity on aquatic organisms received limited attention. In this study, adult zebrafish were exposed to THM at three levels (0.1, 10, and 1000 μg/L) for 45 days to investigate its effect on their ecological behavior, histopathology, bioaccumulation, and stress response. The bioconcentration factor in zebrafish brain was significantly higher (p < 0.05) at low concentration of THM (0.1 μg/L) than in other treatment groups. In terms of individual behavior, the locomotor activity, aggregation, and social activity of fish were enhanced after THM exposure, but the memory of the food zone was disturbed and abnormal swimming behavior was observed. THM exposure caused brain tissue necrosis, erythrocyte infiltration, cloudy swelling, and other pathological changes in brain tissue and affected the concentrations of acetylcholinesterase and cortisol related to neurotoxicity. The condition factor and organ coefficients (brain, heart, and intestine) of zebrafish were markedly impacted by THM treatment at 0.1 and 1000 μg/L, respectively. This finding showed that THM was more harmful to fish behavior than lethality, reproduction, and growth, and a behavioral study can be a useful tool for ecological risk assessment.

Role of non-neuronal cholinergic system in the early stage response of epithelial-mesenchymal transformation related markers in A549 cells induced by coal particles

ObjectiveThis study was aimed to investigate the role of non-neuronal cholinergic system (NNCS) in the early stage response of epithelial-mesenchymal transformation (EMT) related markers in human lung adenocarcinoma A549 cells induced by coal particles. MethodsA549 cells were exposed to different concentrations of GBW11110K, GBW11126D and exogenous acetylcholinesterase (AChE) (the exposure doses were determined according to the results of CCK-8 experiment, and the doses that had no significant effects on cell viability were selected) for 24 h. After exposure, the indexes of oxidative stress (SOD and MDA), inflammatory factors (IL-6 and TNF-α), EMT marker proteins (E-cadherin and vimentin), AChE enzymatic activity and mRNA expression levels of different types of acetylcholine receptors (CHRM3, CHRM5, CHRNA5, CHRNA7, CHRNA9 and CHRNB2) were determined. ResultsGBW11110K and GBW11126D exposure could lead to the following injury effects: the levels of oxidative stress and inflammatory factors changed to a certain extent (SOD decreased gradually, while MDA, IL-6 and TNF-α increased). The protein level of E-cadherin decreased while the vimentin level increased (P < 0.05), suggesting the occurrence of EMT. The AChE enzymatic activity decreased gradually. The expression of acetylcholine receptor mRNA changed as follows (GBW11110K/GBW11126D: CHRM3 (↑↑), CHRM5 (↓↓), CHRNA5 (↓↓), CHRNA7 (↓↓), CHRNA9 (– ↑), CHRNB2 (– –). The addition of exogenous AChE recombinant protein could antagonize the damage effects caused by the coal particles to a certain extent. ConclusionThe coal particle exposure could induce the change of oxidative stress response, inflammatory response and EMT related markers, down-regulate the AChE enzymatic activity, and interfere the mRNA expression levels of AChRs in A549 cells. The addition of exogenous AChE recombinant protein could reverse the above effects to a certain extent.

Stimuli-responsive conductive hydrogel touch sensor for electrochemical and fluorescence monitoring of acetylcholinesterase activity and inhibition

In this study, we produced a stimuli-responsive electrochemical and fluorescence biosensor using carbonized diselenide-crosslinked polymer dot-loaded polydopamine nanoparticles (PDA@dsPD) incorporated into polyvinyl alcohol/chitosan hydrogel, to examine the activity and inhibition of acetylcholinesterase (AChE). The PDA@dsPD inside the hydrogels (i.e., PDA@dsPD-Hydrogel) was sensitive to AChE in the presence of acetylthiocholine, which formed thiocholine that dissolved the diselenide bonds and simultaneously released polydopamine nanoparticles; this affected the optical and electronic performance of the hydrogel. The electronic response-based pressure and strain on the PDA@dsPD-Hydrogel shifted to 23 % when the AChE concentration was 300 U/L, while in the absence of AChE, this value shifted to 46 %. The PDA@dsPD-Hydrogels were able to visualize the AChE fluorescence signal expressed by PC-12 cells, in addition to an increase in electronic conductivity after the cleavage of the diselenide bond. In contrast, no change in the electrochemical or fluorescence signals was observed in the presence of neostigmine, an AChE inhibitor. The novel PDA@dsPD-Hydrogel can even be connected to a wireless electronic device to facilitate the detection of AChE via smartphones.

A sensitive and selective fluorescent probe for acetylcholinesterase: Synthesis, performance, mechanism and application

The detection of acetylcholinesterase (AChE) activity is of great significance for studying the physiological functions of AChE and clinical diagnosis of pesticide poisoning. Herein, a small-molecule fluorescent probe BDFA was rationally designed and readily synthesized via a one-step reaction, which enables qualitative and quantitative detection of AChE. BDFA emits a slight fluorescence in an aqueous medium, while the fluorescence is significantly enhanced under the catalysis of AChE. Mechanism studies reveal that BDFA eliminates the N, N-dimethyl carbamate protective group in the presence of AChE and then spontaneously undergoes intramolecular cyclization conversion to generate an intense fluorescent product. Based on the above mechanism, BDFA exhibits a sensitive, selective, rapid and stable “turn-on” fluorescence response to AChE, without interference from pH, ions, thiols, amino acids and other enzymes. The fluorescence intensity of BDFA at 525 nm has a linear relationship with the AChE concentration in the range of 0.0045–1.0 U/mL, and the detection limit is 4.5 mU/mL. Moreover, BDFA is suitable for rapidly diagnosing AChE activity in blood samples, thus providing an efficient and convenient tool for diagnosing organophosphorus and carbamate pesticide poisoning. Compared with the reported AChE fluorescent probes, BDFA exhibits apparent advantages including simple synthesis, low detection limit and fast response speed.

Microfluidic Paper Based Analytical Devices for the Detection of Carbamate Pesticides.

Microfluidic paper-based analytical devices (μ-PADs) are a new technology platform for the development of extremely low-cost sensing applications. In this study, μ-PADs has been developed for quantitative determination of carbamate pesticides. Key experimental parameters including concentration and volume of acetylcholinesterase, acetylthiocholine iodide and 5,5'-dithiobis-(2-nitrobenzoicacid), incubation time and image capturing time were systematically optimized. Under optimal conditions, the method showed wide range of linearity (0.25-16mg/L), repeatability (4%-5% RSD) and intermediate precision (7%-10% RSD). Limit of detection was observed to be 0.4, 0.24 and 0.46mg/L for carbaryl, carbosulfan and furathiocarb, respectively. An acceptable mean recovery (87% to 94%) was observed for the three pesticides at 1mg/L fortification level. The results reveal that the developed method requires minimal reagents, simple and is easy to handle. It can be used for the quantification of carbamate pesticides in resource limited laboratories without the need for the conventional analytical instruments.

Rapid screening for acetylcholinesterase inhibitors in Selaginella doederleinii Hieron by using functionalized magnetic Fe3O4 nanoparticles.

Insufficient acetylcholine (ACh) can cause cognitive and memory dysfunction, clinically known as, Alzheimer's disease (AD). Acetylcholinesterase (AChE) can hydrolyze ACh into acetic acid and inactivate choline. Therefore, inhibiting the activity of AChE would help to improve the effectiveness of AD treatment. Currently, the methods for rapid screening of AChE inhibitors are limited. This study reports the application of AChE-immobilized magnetic nanoparticles as a drug screening tool to screen AChE inhibitors for natural products. First, AChE was immobilized on a surface of amino-modified magnetic nanoparticles using covalent binding and the AChE concentration, and the pH as well as time was optimized to obtain the maximum enzyme immobilization yield (61.4μg/mg), and the kinetic model indicated that AChE-immobilized magnetic nanoparticles and the substrate had the high affinity and specificity. Then, a ligand fishing experiment was carried out using a mixed model of tacrine (an inhibitor of AChE) and caffeic acid (a non-inhibitor of AChE) to verify the specificity of the immobilized AChE, and the conditions for ligand fishing were further optimized. Finally, the optimized immobilized AChE was combined with UPLC-MS to screen for AChE inhibitors in Selaginella doederleinii Hieron extracts. Four compounds were confirmed to be potent AChE inhibitors. Among the four compounds, amentoflavone had a stronger AChE inhibitory effect than tacrine (positive control) with an IC50 of 0.73±0.009μmol/L. The results showed that AChE-functionalized magnetic nanoparticles can be used in the discovery of target drugs from complex matrices.

Formation and Characterization of a Stable Monolayer of Active Acetylcholinesterase on Planar Gold.

Enzyme activity is the basis for many biosensors where a catalytic event is used to detect the presence and amount of a biomolecule of interest. To create a practical point-of-care biosensor, these enzymes need to be removed from their native cellular environments and immobilized on an abiological surface to rapidly transduce a biochemical signal into an interpretable readout. This immobilization often leads to loss of activity due to unfolded, aggregated, or improperly oriented enzymes when compared to the native state. In this work, we characterize the formation and surface packing density of a stable monolayer of acetylcholinesterase (AChE) immobilized on a planar gold surface and quantify the extent of activity loss following immobilization. Using spectroscopic ellipsometry, we determined that the surface concentration of AChE on a saturated Au surface in a buffered solution was 2.77 ± 0.21 pmol cm-2. By calculating the molecular volume of hydrated AChE, corresponding to a sphere of 6.19 nm diameter, divided by the total volume at the AChE-Au interface, we obtain a surface packing density of 33.4 ± 2.5% by volume. This corresponds to 45.1 ± 3.4% of the theoretical maximum monolayer coverage, assuming hexagonal packing. The true value, however, may be larger due to unfolding of enzymes to occupy a larger volume. The enzyme activity and kinetic measurements showed a 90.6 ± 1.4% decrease in specific activity following immobilization. Finally, following storage in a buffered solution for over 100 days at both room temperature and 4 °C, approximately 80% of this enzyme activity was retained. This contrasts with the native aqueous enzyme, which loses approximately 75% of its activity within 1 day and becomes entirely inactive within 6 days.

Near-infrared fluorescent probe for in vivo monitoring acetylcholinesterase activity

Acetylcholinesterase (AChE) plays an important role in the process of chemotherapy drug-induced cell apoptosis and is also an apoptosis marker to diagnose disease and assay the effect of the drug. Thus, we designed and synthesized a novel near-infrared fluorescent probe (NFL-SF) to detect AChE activity, which contained near-infrared (NIR) fluorophore NFL-OH and 2-thienylformyl chloride as the recognition unit. The probe has higher specificity and sensitivity to AChE and excellent biocompatibility. With the increasing concentration of AChE, the probe displayed an enhanced fluorescence signal at 745 nm for 30 min, with the detection limit of 0.2 mU/mL. In addition, NFL-SF not only detected exogenous AChE activity, but also effectively monitored the endogenous AChE activity of chemotherapeutic drug-induced cell apoptosis in living cells. When the AChE activity was inhibited with donepezil, the fluorescence intensity of the NIR channel was significantly reduced. Notably, the probe was successfully applied to in vivo imaging of nude mice. We believe that this probe could provide a strategy for rapidly and visually monitoring AChE activity.

Scopolamine으로 유도된 인지장애 마우스의 기억력 개선 효과에 대한 인삼, 생지황, 발효홍삼 추출물의 비교 연구

In this study, we investigated the effects of Ginseng Radix (G), Rehmanniae Radix (R), and Fermented red-ginseng extracts (FRG) on cognitive function in scopolamine-induced memory-impaired mice. We measured the effects of G, R, and FRG on the improvement of memory and cognition via behavior analysis. In addition, we measured the acetylcholinesterase (AChE) activity in the hippocampus of each group of mice. The expression of β-amyloid, Tau, and BDNF in the brain tissues were observed through immunohistochemical staining. Ginseng Radix (G) and Fermented red-ginseng (FRG) have effectively improved cognitive function in the water maze test. Ginseng Radix (G), Rehmanniae Radix (R), and Fermented red-ginseng (FRG) have improved the willingness of mice to explore the new environment, as confirmed by Y maze test. In addition, immunohistochemical staining revealed that Ginseng Radix (G) decreased the expression of β-amyloid and Tau in the hippocampus. In addition, fermented red-ginseng (FRG) increased the expression of BDNF. Ginseng Radix (G), Rehmanniae Radix (R), and Fermented red-ginseng (FRG) have decreased the concentration of acetylcholinesterase in the hippocampus as compared with the control group of mice. In conclusion, Ginseng Radix (G), Rehmanniae Radix (R), and Fermented red-ginseng (FRG) are considered to have the potential for development as candidate drugs to control the progression of Alzheimer

Pantao Pill Improves the Learning and Memory Abilities of APP/PS1 Mice by Multiple Mechanisms.

Background: To explore the effect and mechanisms of Pantao Pill (PTP) on cognitive impairment. Methods: Network pharmacology was performed to analyze the mechanism of PTP treating cognitive impairment. The targets of PTP and cognitive impairment were predicted and used to construct protein-protein interaction (PPI) networks. The intersection network was selected, and the core network was obtained through topological analysis. Enrichment analysis was conducted to obtain the GOBP terms and KEGG pathways. We then performed experiments to validate the results of the network pharmacology by using an APP/PS1 transgenic mouse model. The APP/PS1 mice were divided into four groups: the model group, the high-dose PTP (3.6 g/kg·d) group, the low-dose PTP (1.8 g/kg·d) group, and the positive control group (donepezil hydrochloride, 2 mg/kg·d). Wild-type (WT) C57 mice served as a normal control group. PTP and donepezil were administered by gavage for 8 weeks. Results: Network pharmacology showed that PTP might improve cognitive impairment by regulating autophagy, apoptosis, and oxidative stress. For the Morris water maze test, a significant difference was shown in the total swimming distance among groups (p < 0.05) in the positioning navigation experiment, and with training time extension, the swimming speed increased (p < 0.01). In the space probe test, PTP administration significantly reduced the swimming path length and the escape latency of APP/PS1 mice (p < 0.05 or p < 0.01), whereas it had no effect on the swimming speed (p > 0.05). PTP (3.6 g/kg/d) rescued the reduction of norepinephrine and acetylcholine levels (p < 0.05), and increased the acetylcholinesterase concentration (p < 0.05) in the brain tissue. PTP (1.8 g/kg/d) increased the norepinephrine level (p < 0.01). PTP rescued the activity reduction of superoxide dismutase in the brain tissue (p < 0.01) and the neuron cell pyknosis in the hippocampal CA region (p < 0.05). PTP reduced ATG12 and PS1 expression (p < 0.05 or p < 0.01), and increased Bcl-2 expression in the brain tissue (p < 0.05). Conclusion: PTP can significantly improve the learning and memory abilities of APP/PS1 mice, and the mechanism may be related to the increase of neurotransmitter acetylcholine and norepinephrine levels, the reduction of the excessive autophagic activation, and the suppression of oxidative stress and excessive apoptotic activity.

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

Acrylamide (ACR) is a chemical compound that exhibits neurotoxic and genotoxic effects. It causes neurological symptoms such as tremors, general weakness, numbness, tingling in the limbs or ataxia. Numerous scientific studies show the effect of ACR on nerve endings and its close connection with the cholinergic system. The cholinergic system is part of the autonomic nervous system that regulates higher cortical functions related to memory, learning, concentration and attention. Within the cholinergic system, there are cholinergic neurons, anatomical cholinergic structures, the neurotransmitter acetylcholine (ACh) and cholinergic receptors. Some scientific reports suggest a negative effect of ACR on the cholinergic system and inflammatory reactions within the body. The aim of the study was to review the current state of knowledge on the influence of acrylamide on the cholinergic system and to evaluate its possible effect on inflammatory processes. The cholinergic anti-inflammatory pathway (CAP) is a neuroimmunomodulatory pathway that is located in the blood and mucous membranes. The role of CAP is to stop the inflammatory response in the appropriate moment. It prevents the synthesis and the release of pro-inflammatory cytokines and ultimately regulates the local and systemic immune response. The cellular molecular mechanism for inhibiting cytokine synthesis is attributed to acetylcholine (ACh), the major vagal neurotransmitter, and the α7 nicotinic receptor (α7nAChR) subunit is a key receptor for the cholinergic anti-inflammatory pathway. The combination of ACh with α7nAChR results in inhibition of the synthesis and release of pro-inflammatory cytokines. The blood AChE is able to terminate the stimulation of the cholinergic anti-inflammatory pathway due to splitting ACh. Accordingly, cytokine production is essential for pathogen protection and tissue repair, but over-release of cytokines can lead to systemic inflammation, organ failure, and death. Inflammatory responses are precisely regulated to effectively protect against harmful stimuli. The central nervous system dynamically interacts with the immune system, modulating inflammation through the humoral and nervous pathways. The stress-induced rise in acetylcholine (ACh) level acts to ease the inflammatory response and restore homeostasis. This signaling process ends when ACh is hydrolyzed by acetylcholinesterase (AChE). There are many scientific reports indicating the harmful effects of ACR on AChE. Most of them indicate that ACR reduces the concentration and activity of AChE. Due to the neurotoxic effect of acrylamide, which is related to the disturbance of the secretion of neurotransmitters, and its influence on the disturbance of acetylcholinesterase activity, it can be concluded that it disturbs the normal inflammatory response.

The fabrication and assessment of mosquito repellent cream for outdoor protection

Mosquito-borne infections like dengue, malaria, chikungunya, etc. are a nuisance and can cause profound discomfort to people. Due to the objectional side effects and toxicity associated with synthetic pyrethroids, N,N-diethyl-3-methylbenzamide (DEET), N,N-diethyl phenylacetamide (DEPA), and N,N-di ethyl benzamide (DEBA) based mosquito repellent products, we developed an essential oil (EO) based mosquito repellent cream (EO-MRC) using clove, citronella and lemongrass oil. Subsequently, a formulation characterization, bio-efficacy, and safety study of EO-MRC were carried out. Expression of Anti-OBP2A and TRPV1 proteins on mosquito head parts were studied by western blotting. In-silico screening was also conducted for the specific proteins. An FT-IR study confirmed the chemical compatibility of the EOs and excipients used in EO-MRC. The thermal behaviour of the best EOs and their mixture was characterized by thermogravimetric analysis (TGA). GC–MS examination revealed various chemical components present in EOs. Efficacy of EO-MRC was correlated with 12% N,N-diethyl benzamide (DEBA) based marketed cream (DBMC). Complete protection time (CPT) of EO-MRC was determined as 228 min. Cytotoxicity study on L-132 cell line confirmed the non-toxic nature of EO-MRC upon inhalation. Acute dermal irritation study, acute dermal dose toxicity study, and acute eye irritation study revealed the non-toxic nature of EO-MRC. Non-target toxicity study on Danio rerio confirmed EO-MRC as safer for aquatic non-target animals. A decrease in the concentration of acetylcholinesterase (AChE) was observed in transfluthrin (TNSF) exposed Wistar rats. While EO-MRC did not alter the AChE concentrations in the exposed animals. Results from western blotting confirmed that Anti-OBP2A and TRPV1 proteins were inhibited in TNSF exposed mosquitoes. Mosquitoes exposed to EO-MRC showed a similar expression pattern for Anti-OBP2A and TRPV1 as the control group. In silico study revealed eight identified compounds of the EOs play significant roles in the overall repellency property of the developed product. The study emphasizes the mosquito repellent activity of EO-MRC, which could be an effective, eco-friendly, and safer alternative to the existing synthetic repellents for personal protection against mosquitoes during field conditions.

Differential effects of voluntary and forced exercise trainings on spatial learning ability and hippocampal biomarkers in aged female rats

This study aimed to compare the effects of voluntary and forced exercise trainings on cognitive functions and to evaluate their relationship with hippocampal synaptic proteins, neurotrophic factors and markers of oxidative damage in aged female rats. Aged female rats were randomly assigned to control, voluntary exercise training and forced exercise training groups. Voluntary or forced exercise trainings were performed for 12 weeks. At the end of the training period, cognitive functions of the animals were assessed with Morris water maze (MWM) test. After the behavioral test, hippocampus tissues were taken for the analysis of synaptophysin, acetylcholinesterase (AChE), brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), malondialdehyde (MDA), protein carbonyl (PC), glutathione (GSH) and superoxide dismutase (SOD). During the MWM test, the number of platform crossings was higher in the voluntary exercise group than in the control group (P < 0.05). In the hippocampus tissue, levels of the synaptophysin, BDNF, NGF and SOD were higher, but MDA levels were lower in the voluntary exercise group than in the control group (P < 0.05). Additionally, hippocampal AChE concentration was higher, but PC levels were lower in the both voluntary and forced exercise groups than in the control group (P < 0.05). In conclusion, voluntary exercise was more effective intervention to improve spatial learning ability in aging process. Increased neurotrophic factors, synaptic proteins, and improved oxidative damage may play a role in these positive effects.

Moringa oleifera Ameliorates Chlorpyrifos Induced Oxidative Stress in Male Wistar Rats

Background: Chlorpyrifos is a widely used organophosphate pesticide. It exerts its toxic effect by inhibiting of cholinesterases and induction of oxidative stress. Methods: In the present study,Soya oil, Chlopyrifos,Moringa oleifera, Chlopyrifos + Moringa oleifera, were given to male rats through gavage for 2 weeks.The influence of chlorpyrifos on brain cholinesterase activity and indicators of oxidative stress malondialdehydecatalase, glutathione, superoxide dismutaseand also histopathological changes in the brain of Wistar rats was investigated compared to control group. Results: There was significant increase in the brain malondialdehyde of the chlopyrifos group compared to the control and chlopyrifos+Moringa oleifera group. Also there were significant decreases in the superoxide dismutase, catalase, glutathione and acetylcholinesterase concentrations in the chlopyrifosgroup compared to the control and chlopyrifos + Moringa oleifera group. The rats showed significant changes in body, liver, kidneys and heart weights No significant haematological changes were seen following treatment. While some histopathological changes were detected in brain tissues in the chlopyrifos treated group, less histopathological changes were observed in chlopyrifos +Moringa oleifera treated groups at the end of the 2 weeks’ study. Conclusion: Overall, these results support the hypothesis that chlopyrifos causes oxidative stress and Moringa oleiferaextract can help reduce the changes induced by chlopyrifos.

Alteration of the α5 GABA receptor and 5HTT lead to cognitive deficits associated with major depressive-like behaviors in a 14-day combined stress rat model

Introduction: Current models used to study the pathophysiology of major depressive disorder (MDD) are laborious and time consuming. This study examined the effect of a 14-day combined stress model (CS; corticosterone injection and restraint stress) in male Sprague-Dawley rats and also compare the effect of CS versus 28-day corticosterone treatment on depressive-like behaviour and cognitive deficits. Materiel and methods: Depressive-like behaviours and cognitive deficits were assessed in the forced swim test (FST), sucrose preference (SPT), Morris water maze (MWM) and novel object recognition (NORT) tests. Real-time PCR and ELISA were respectively used to detect expression of the serotonin transporter (5-HTT), serotonin 1 A receptor (5-HT1A), α5 GABAA receptor, and the concentrations of corticosterone (plasma), GABA and acetylcholinesterase (AChE) in the hippocampus and Prefrontal cortex (PFC). Results CS group showed increased immobility time in the FST, time to reach the MWM platform, higher corticosterone level, and increased expressions of hippocampal and PFC 5-HT1A and α5 GABAA receptors, and AChE compared to their control groups. In contrast, reductions in SPT ratio, discrimination index in NORT, time in target quadrant, and hippocampal 5-HTT expression was noted relative to their control group. Compared to the 28-day corticosterone only group, PFC 5-HT1A, Hippocampal 5-HTT were reduced, while PFC 5-HTT, Hippocampal α5 GABAA receptors, and AChE concentrations were higher in the CS group. Conclusion: Our CS model induced depressive-like behaviour with early cognitive deficits in rats affecting both hippocampus and PFC. The CS model may be useful in investigating new and comprehensive treatment strategies for MDD.

Possible Contribution of Altered Cholinergic Activity in the Visual Cortex in Visual Hallucinations in Parkinson's Disease.

Up to one-third of patients with Parkinson's disease (PD) experience visual hallucinations (VHs). Lewy bodies are sparse in the visual cortices and seem unlikely to explain the hallucinations. Some neuroimaging studies have found that perfusion is reduced in the occipital lobe in individuals with VHs. Recent work has suggested that decreased cholinergic input may directly lead to the decreased perfusion. The investigators hypothesized that individuals with PD and VHs would have biochemical evidence of reduced microvascular perfusion and reduced cholinergic activity in areas of the brain that process visual images. Tissue from Brodmann's area (BA) 18 and BA 19 was obtained from a well-characterized cohort matched for age, gender, and postmortem interval in 69 individuals (PD without VHs, N=11; PD without dementia plus VHs N=10, N=10; PD with dementia plus VHs, N=16; and control subjects, N=32). Von Willebrand factor, vascular endothelial growth factor A, and myelin-associated glycoprotein:proteolipid protein-1 (MAG:PLP1) ratio-a measure of tissue oxygenation relative to metabolic demand, acetylcholinesterase (AChE), butyrylcholinesterase (BChE), choline acetyltransferase, and α-synuclein-were quantified by enzyme-linked immunosorbent assay. The primary outcome was the MAG:PLP1 ratio. There was no biochemical evidence of chronic hypoperfusion in PD, although microvessel density was decreased in ventral BA 18 and BA 19. There was no between-group difference in BChE in either dorsal BA 18 or BA 19. AChE concentration was reduced in individuals with PD compared with control subjects in dorsal and ventral BA 18 and dorsal BA 19, and it was increased in ventral BA 19. These changes were most marked in the PD plus VHs group. These results suggest that changes in cholinergic activity rather than chronic hypoperfusion may underlie VHs in PD.

Inhibition of aluminum chloride-induced amyloid Aβ peptide accumulation and brain neurodegeneration by Bougainvillea spectabilis flower decoction.

Objective(s): To investigate the potential therapeutic effect of Bougainvillea spectabilis flower decoction on aluminum chloride (AlCl3)-induced neurotoxicity. Materials and Methods:Rats received daily intraperitoneal injections of AlCl3 at 10 mg/kg for two months and were treated with B. spectabilis decoction at 50 or 100 mg/kg or saline during the 2nd month of the study. The control group received saline. Brain malondialdehyde (MDA), nitric oxide (NO), reduced glutathione (GSH), acetylcholinesterase (AChE), amyloid Aβ peptide, and interleukin-6 (IL-6) concentrations and paraoxonase-1 (PON-1) activity were determined and brain histology was done. Behavioral and neurological testing included Morris water maze (WMZ), Y maze, and wire hanging. Results:Compared with saline controls, AlCl3 significantly increased brain MDA and NO along with decreased GSH and PON-1 activity. It also increased AChE, IL-6, and amyloid Aβ concentrations. AlCl3 impaired motor strength and memory performance and caused brain neurodegeneration. B. spectabilis decoction given at 50 or 100 mg/kg protected against the biochemical and histopathological alterations evoked by AlCl3 by alleviating the increase in MDA and NO, and decrease in GSH and PON-1 activity. B. spectabilis decoction showed no significant effect on AChE but markedly decreased IL-6 and amyloid Aβ in the brain of AlCl3-treated rats. It also restored memory performance and motor strength, and protected against AlCl3-induced neurodegeneration.Conclusion:These results suggest that B. spectabilis flower decoction might prove of value in the treatment of Alzheimer’s disease.

Pesticides use and health impacts on farmers in Thailand, Vietnam, and Lao PDR: Protocol for a survey of knowledge, behaviours and blood acetyl cholinesterase concentrations.

Pesticides use in Southeast Asia has increased steadily, driven by the growth of large-scale commercial farming, as well as a desire to maximise food production in rural subsistence economies. Given that use of chemical pesticides, such as organophosphates and carbamates, has known potential health impacts, there are concerns about the safety of agricultural workers, and a need for a better evidence base to underpin regulation and worker education. This study, undertaken in 9 districts in Lao PDR, Thailand and Vietnam, will interview agricultural workers to investigate how they use pesticides, their knowledge of risks and self-protective practices, and their self-reported illness symptoms. In each district researchers will recruit and interview 120 participants engaged in vegetable farming, who have recently used pesticides, making a total of 1080 subjects divided equally between the three study countries. Workers’ degree of pesticides exposure will be determined from acetyl cholinesterase concentrations in capillary blood samples collected using field test kits, and these data will be analysed together with the interview findings. Country findings will be compared and contrasted, and general patterns noted. Knowledge gained about risky behaviours, self-protective practices and degree of association with serious pesticides exposure will assist policy makers and inform health improvement programmes.

Cnidoscolus aconitifolius-supplemented diet enhanced neurocognition, endogenous antioxidants and cholinergic system and maintains hippocampal neuronal integrity in male Wistar rats.

Cnidoscolus aconitifolius have been investigated to have abundant phytochemicals. However, study on the effect of Cnidoscolus aconitifolius on neurobehavioral performance when supplemented with diet is lacking. The study is aimed at investigating the memory-enhancing effect of Cnidoscolus aconitifolius-supplemented diet (CAD) using Morris water maze and Novel object recognition test. Ninety male Wistar rats (80-100g) were fed with CAD (1, 2.5, 5 and 10%) continuously for a period of 4, 8 and 12weeks respectively. Six animals per group were used for assessment of memory performance (Morris water maze [MWM] and Novel object recognition test [NORT]); afterwards the brain tissues were harvested for malondialdehyde (MDA), glutathione (GSH) and catalase (CAT) estimation. Acetylcholinesterase (AChE) concentration was also determined. Hippocampal architectural change in the neuron was examined using hematoxylin and eosin (H&E) and cresyl fast violet (Nissl) stain. Higher percentage of CAD significantly (p<0.05) improve memory performance with time-dependent effects in rats fed with CAD on MMW and NORT. MDA significantly (p<0.05) reduce in 1 and 2.5% CAD groups at 4th weeks and in 2.5 and 5% CAD groups at 8th weeks while GSH concentration significantly (p<0.05) increase at 12th weeks in 2.5 and 10% CAD groups. However, CAT concentration significantly (p<0.05) increase in 2.5, and 5%, CAD groups, 1, 5, and 10% CAD groups and in 5, and 10% CAD groups at 4th, 8th and 12th weeks. AChE significantly (p<0.05) reduce at 4th and 12th weeks. Histological assessment reveals no neuronal and pyramidal degeneration (chromatolysis) at the hippocampal Cornu Ammonis 3 (CA3) region. The results suggest that CAD boost memory performance in rats through positive modulation of oxidative stress, cholinergic system and degeneration of hippocampal neurons.

Cnidoscolus aconitifolius-supplemented diet enhanced neurocognition, endogenous antioxidants and cholinergic system and maintains hippocampal neuronal integrity in male Wistar rats.

Cnidoscolus aconitifolius have been investigated to have abundant phytochemicals. However, study on the effect of Cnidoscolus aconitifolius on neurobehavioral performance when supplemented with diet is lacking. The study is aimed at investigating the memory-enhancing effect of Cnidoscolus aconitifolius-supplemented diet (CAD) using Morris water maze and Novel object recognition test. Ninety male Wistar rats (80-100g) were fed with CAD (1, 2.5, 5 and 10%) continuously for a period of 4, 8 and 12weeks respectively. Six animals per group were used for assessment of memory performance (Morris water maze [MWM] and Novel object recognition test [NORT]); afterwards the brain tissues were harvested for malondialdehyde (MDA), glutathione (GSH) and catalase (CAT) estimation. Acetylcholinesterase (AChE) concentration was also determined. Hippocampal architectural change in the neuron was examined using hematoxylin and eosin (H&E) and cresyl fast violet (Nissl) stain. Higher percentage of CAD significantly (p<0.05) improve memory performance with time-dependent effects in rats fed with CAD on MMW and NORT. MDA significantly (p<0.05) reduce in 1 and 2.5% CAD groups at 4th weeks and in 2.5 and 5% CAD groups at 8th weeks while GSH concentration significantly (p<0.05) increase at 12th weeks in 2.5 and 10% CAD groups. However, CAT concentration significantly (p<0.05) increase in 2.5, and 5%, CAD groups, 1, 5, and 10% CAD groups and in 5, and 10% CAD groups at 4th, 8th and 12th weeks. AChE significantly (p<0.05) reduce at 4th and 12th weeks. Histological assessment reveals no neuronal and pyramidal degeneration (chromatolysis) at the hippocampal Cornu Ammonis 3 (CA3) region. The results suggest that CAD boost memory performance in rats through positive modulation of oxidative stress, cholinergic system and degeneration of hippocampal neurons.