Acetylcholinesterase Activity Levels Research Articles

Neuroprotective effect of ranolazine improves behavioral discrepancies in a rat model of scopolamine-induced dementia.

Ranolazine (Rn), an antianginal agent, acts in the central nervous system and has been used as a potential treatment agent for pain and epileptic disorders. Alzheimer's disease (AD) is one of the most prevalent neurodegenerative diseases and the leading factor in dementia in the elderly. We examined the impact of Rn on scopolamine (Sco)-induced dementia in rats. Thirty-two albino male rats were divided into four groups: control, Rn, Sco, and Rn + Sco. A significant decrease in the escape latency in the Morris water maze test after pre-treatment with Rn explained better learning and memory in rats. Additionally, Rn significantly upregulated the activities of the antioxidant enzymes in the treated group compared to the Sco group but substantially reduced acetylcholinesterase activity levels in the hippocampus. Moreover, Rn dramatically reduced interleukin-1 β (IL-1β) and IL-6 and upregulated the gene expression of brain-derived neurotrophic factor (BDNF). Furthermore, in the Sco group, the hippocampal tissue's immunohistochemical reaction of Tau and glial factor activating protein (GFAP) was significantly increased in addition to the upregulation of the Caspase-3 gene expression, which was markedly improved by pre-treatment with Rn. The majority of pyramidal neurons had large vesicular nuclei with prominent nucleoli and appeared to be more or less normal, reflecting the all-beneficial effects of Rn when the hippocampal tissue was examined under a microscope. Our findings indicated that Rn, through its antioxidative, anti-inflammatory, and anti-apoptotic effects, as well as the control of the expression of GFAP, BDNF, and Tau proteins, has a novel neuroprotective impact against scopolamine-induced dementia in rats.

Positive association of acetylcholinesterase (AChE) with the neutrophil-to-lymphocyte ratio and HbA1c, and a negative association with hydrogen sulfide (H2S) levels among healthy African Americans, and H2S-inhibition and high-glucose-upregulation of AChE in cultured THP-1 human monocytes

The incidence of Alzheimer's disease (AD) is higher in people over the age of 65 and in African Americans (AA). Elevated acetylcholinesterase (AChE) activity has been considered a major player in the onset of AD symptoms. As a result, many FDA-approved AD drugs target AChE inhibition to treat AD patients. Hydrogen sulfide (H2S) is a signaling molecule known to downregulate oxidative stress and inflammation. The neutrophil-to-lymphocyte ratio (NLR) in the blood is widely used as a biomarker to monitor inflammation and immunity. This study examined the hypothesis that plasma AChE levels have a negative association with H2S levels and that a positive association exists between levels of NLR, HbA1c, and ROS with the AChE in the peripheral blood. The fasting blood sample was taken from 114 African Americans who had provided written informed consent approved by the IRB. The effect of H2S and high-glucose treatment on AChE activity levels was also investigated in THP-1 human monocytes. There was a significant negative relationship between AChE and the levels of H2S (r = -0.41, p = 0.001); a positive association between the levels of AChE with age (r = 0.26, p = 0.03), NLR (r = 0.23, p = 0.04), ROS (r = 0.23, p = 0.04) and HbA1c levels (r = 0.24, p = 0.04), in AA subjects. No correlation was seen between blood levels of AChE and acetylcholine (ACh). Blood creatinine had a negative correlation (r = -0.23, p = 0.04) with ACh levels. There was a significant effect of H2S on AChE inhibition and of high glucose in upregulating AChE activity in cultured monocytes. This study suggests hyperglycemia and lower H2S status can contribute to an increase in the AChE activity levels. Future clinical studies are needed to examine the potential benefits of supplementation with hydrogen sulfide pro-drugs/compounds in reducing the AChE and the cognitive dysfunctions associated with AD.

Chronic oral exposure of aluminum chloride in rat modulates molecular and functional neurotoxic markers relevant to Alzheimer’s disease

Aluminum is an environmentally abundant potential neurotoxic agent that may result in oxidative damage to a range of cellular biomarkers. The potential sources of aluminum accumulation in the body include drinking water, food, medicines, vaccines, and aluminum cookware utensils, etc. The accumulation of aluminum in the brain is reported to be associated with cholinergic dysfunction, oxidative stress and neuronal damage, which may ultimately cause Alzheimer’s disease. Since chronic exposure to aluminum leads to its accumulation in the brain, so this study was done by a long-term (24 weeks) low dose (20 mg/kg) oral exposure of aluminum chloride in rats. In this chronic model, we have evaluated the major hallmarks of Alzheimer’s disease including amyloid-beta (Aβ1–42) and phosphorylated-tau (p231-tau) protein in brain tissue. Furthermore, we evaluated the level of acetyl cholinesterase activity, inflammatory cytokines such as TNF-α, IL-6 and IL-1β, and oxidative stress biomarkers in the rat brain in this model. The neurobehavioral parameters were also assessed in animals by using spontaneous locomotor activity, passive avoidance, rotarod test and novel object recognition test to evaluate alteration in learning, memory and muscle co-ordination. We found that chronic oral exposure to aluminum chloride causes a significant increase in structural hallmarks such as Aβ1–42 and p231-tau levels along with pro-inflammatory cytokines (TNF-α and IL-6), oxidative stress, and a decrease in antioxidant markers such as GSH and catalase in the brain tissue. These biomarkers significantly affected neurobehavioral parameters in animals. This study provides a mechanistic understanding of chronic aluminum-induced neuronal toxicity in the brain with relevance to Alzheimer’s disease.

Genetic Differences in Dorsal Hippocampus Acetylcholinesterase Activity Predict Contextual Fear Learning Across Inbred Mouse Strains.

Learning is a critical behavioral process that is influenced by many neurobiological systems. We and others have reported that acetylcholinergic signaling plays a vital role in learning capabilities, and it is especially important for contextual fear learning. Since cholinergic signaling is affected by genetic background, we examined the genetic relationship between activity levels of acetylcholinesterase (AChE), the primary enzyme involved in the acetylcholine metabolism, and learning using a panel of 20 inbred mouse strains. We measured conditioned fear behavior and AChE activity in the dorsal hippocampus, ventral hippocampus, and cerebellum. Acetylcholinesterase activity varied among inbred mouse strains in all three brain regions, and there were significant inter-strain differences in contextual and cued fear conditioning. There was an inverse correlation between fear conditioning outcomes and AChE levels in the dorsal hippocampus. In contrast, the ventral hippocampus and cerebellum AChE levels were not correlated with fear conditioning outcomes. These findings strengthen the link between acetylcholine activity in the dorsal hippocampus and learning, and they also support the premise that the dorsal hippocampus and ventral hippocampus are functionally discrete.

Hydrolase-Treated Royal Jelly Attenuates H2O2- and Glutamate-Induced SH-SY5Y Cell Damage and Promotes Cognitive Enhancement in a Rat Model of Vascular Dementia.

Vascular dementia (VaD) is the second most common type of dementia following Alzheimer's disease, but the therapeutic efficacy is still not effective. This makes the searching for novel neuroprotective agents important. Therefore, we hypothesized that royal jelly, a well-known traditional medicine, could attenuate memory impairment and brain damage in vascular dementia. This study determined the effects of royal jelly hydrolysate (RJH) and possible mechanism of cell damage and cognitive-enhancing effect in animal study. An in vitro study assessed the effects of RJH on acetylcholinesterase inhibitor, cell viability, and cell damage in SH-SY5Y neuroblastoma cells. Then, an in vivo study examined vascular dementia by the occlusion of the right middle cerebral artery (Rt.MCAO); adult male Wistar rats had been orally given RJH at doses ranging from 10, 50, to 100 mg/kg for 14 days before and 14 days after the occlusion of Rt.MCAO to mimic the VaD condition. Rats' spatial memory was evaluated using Morris water maze and radial arm maze every 7 days after Rt.MCAO throughout a 14-day experimental period, and then, they were sacrificed and the acetylcholinesterase (AChE) activity in the hippocampus was determined. The results showed that RJH has no cytotoxic effect with the final concentration up to 500 μg protein/ml and reduces cell death from the H2O2- and glutamate-induced cell damage in in vitro neuroblastoma cells. Importantly, RJH significantly improved memory performance in Morris water maze test and radial arm maze and decreased the level of acetyl cholinesterase activity. In conclusion, RJH is the potential neuroprotective agent and cognitive enhancer for VaD.

Biomarker Responses of the Clam Ruditapes decussatus Exposed to a Complex Mixture of Environmental Stressors under the Influence of an Urban Wastewater-Treatment Plant.

To evaluate the potential impact of an urban wastewater-treatment plant on Ria Formosa coastal lagoon, a sentinel species, the clam Ruditapes decussatus, was exposed along a gradient of the effluent's dispersal for 1 mo. Three exposure sites were selected to study the responses of 3 biomarkers: electron transport system, acetylcholinesterase, and lipid peroxidation. As complementary data, morphometric measurements, condition index, and lipid and protein content were considered together with in situ physicochemical characterization of the sites (temperature, salinity, pH, and dissolved oxygen). Electron transport system activity levels were between 35.7 and 50.5 nmol O2 /min g protein, acetylcholinesterase activity levels ranged from 2.6 to 3.8 nmol/min g protein, and lipid peroxidation ranged from 174.7 to 246.4 nmol malondialdehyde/g protein. The exposure sites shaped the response not only of biomarkers but also of "health" parameters (protein, lipids, and condition index). Lipid peroxidation was the most responsive biomarker also associated with electron transport system, especially at the closest site to the urban wastewater-treatment plant. Because of the presence of complex mixtures of contaminants in urban effluents, biomarker responses can provide valuable information in environmental assessment. However, it is vital to identify all biological and ecological factors induced by the natural life cycle of clams. Abiotic factors can mask or overlap the response of biomarkers and should be considered in a multibiomarker approach. Environ Toxicol Chem 2021;40:272-283. © 2020 SETAC.

Histochemical Staining of Acetylcholinesterase in Carnolian Honeybee (Apis mellifera carnica) Brain after Chronic Exposure to Organophosphate Diazinon

Abstract Organophosphate insecticides are known to inhibit the activity of enzyme acetylcholinesterase. They affect olfactory learning and memory formation in honeybees. These insecticides cause mushroom body inactivation in honeybees, but their influence on other brain regions involved in olfactory perception and memory is unknown. The goal of this study was to study the effects of organophosphate insecticide diazinon on carnolian honeybee (Apis mellifera carnica) acetylcholinesterase activity in the olfactory brain regions of antennal lobe, mushroom body and lateral procerebrum (lateral horn). The lamina, medulla and lobula of optic lobes were also analyzed. The level of acetylcholinesterase activity was visualized using the histochemical staining method. Densitometric analysis of histochemical signals indicated that diazinon inhibited acetylcholinesterase activity only in the lip of calyces of mushroom body, but not in other analyzed olfactory regions, antennal lobe and lateral procerebrum. The visual brain system optic lobes were also unaffected. This is in accordance with the literature reporting that mushroom body is the main brain center for olfactory learning and memory formation in honeybees.

Arthrophytum scoparium Extract Improves Memory Impairment and Affects Acetylcholinesterase Activity In Mice Brain.

Arthrophytum scoparium (Pomel) Iljin (Amaranthaceae family) has been widely used in traditional Tunisian medicine to treat many disorders such as migraine, headache, and neurological disorders. This study investigates the effect of Arthrophytum scoparium Aqueous Extract (ASAE) on cognitive impairments and oxidative injury induced by galactose (10%) in a mouse model. The mice were divided randomly into 4 experimental groups, including the control group (saline water 9 ‰), Galactose group, Scop group (300 mg/kg/d), and Scop+Gal group (300 mg/kg/d). Mice received the corresponding solutions by intraperitoneal injection (i.p.) for 7 days before the Y-maze active tests. Galactose 10% was given to all groups except control and Scop groups, 30 min before the trial. Levels of Acetylcholinesterase Activity (AChE), Ascorbic Acid (AA), Gluthatione (GSH) and Malondialdehyde (MDA) in mice brains were examined. Chronic administration of galactose significantly impaired cognitive performance in Y maze, caused marked oxidative damages and a significant increase in the acetylcholinesterase activity as compared to other groups. On the contrary, ASAE (300 mg/kg) treatment suppressed galactoseinduced oxidative damage by ameliorating the increased levels of GSH and AA. Moreover, ASAE treatment reduced brain AChE activities in the galactose-induced model. These findings suggest that ASAE exerts potent anti-amnesic effects via the modulation of cholinergic and antioxidant activities. The observed pharmacological activities should be further evaluated by detailed experimental studies and validated by clinical trials.

Larvicidal, biochemical and physiological effects of acetamiprid and thiamethoxam against Culex pipiens L. (Diptera: Culicidae).

The resistance of mosquitos to conventional insecticides created an urgent need for using alternative insecticides. In this study, the toxicity of the neonicotinoids (acetamiprid and thiamethoxam) was evaluated against the 3rd larval instar of Culex pipens. In the larvicidal assay, acetamiprid and thiamethoxam showed promising larvicidal activity against Cx. pipiens, with LC50 values of 0.0093 and 0.0305 ppm after 24 hrs, 0.0078 and 0.0206 ppm after 48 hrs and 0.0065 and 0.0137 ppm after 72 hrs of insecticidal exposure. The activity of acetylcholinesterase (AChE), carboxylesterase, (α-esterase), (β-esterase), and glutathione S- transferase (GST) were determined after 72 hrs of insecticidal exposure. Acetamiprid showed a significant increase in the activity level of AChE, GST, carboxylesterase, α, and β- esterases than thiamethoxam. The hemocytes of the treated 3rd larval instar of Cx. pipens were sensitive to both insecticides and showed remarkable deformation compared with control. Therefore, both detoxification enzymes and physiological resistance play a great role in neonicotinoids detoxification.

Antiepileptic potential of Bacopa monnieri in the rat brain during PTZ-induced epilepsy with reference to cholinergic system and ATPases

Epilepsy is a chronic central nervous system disorder that occurs not only with the imbalance of glutamatergic neurons and inhibitory gamma-aminobutyric acid (γ-GABA) neurons, but also with abnormal Central cholinergic neuronal regulation. Since long term usage of antiepileptic drugs cause high incidence of pharmacoresistance and untoward side effects, attention has been paid in recent years to screen bioactive compounds from natural medicinal plants for the treatment of several neurological disorders including Epilepsy. Keeping in view of relative importance of natural medicinal plants, the present study is mainly focused to characterize the anti-convulsant effect of Bacopa monnieri (BM), an Indian herb which is being extensively used in Ayurvedic treatments related to neurological complications. The present study is designed to assess the neurotoxicity of Pentylene tetrazole (PTZ), an epileptic compound with particular reference to Cholinergic system and ATPases in different brain regions of rat to explore the possible antiepileptic effect of different extracts of BM in comparison with Diazepam (DZ) (Reference control). The activity levels of Acetyl cholinesterase (AChE) and ATPases were decreased in different regions of brain during PTZ induced epilepsy which were increased in epileptic rats pretreated with different extracts of Bacopa monnieri except EAE and AE. In addition Acetylcholine (ACh), levels were increased during PTZ induced epilepsy when compared with normal control and levels were reversed on pretreatment with different extracts of BM. Recoveries of these parameters suggest that the bioactive factors present in the extracts offer neuroprotection by interrupting the pathological cascade that occurs during epileptogenesis.

SAT-133 BLOOD ACETYLCHOLINESTERASE ACTIVITY AND COMPARATIVE eGFR IN RURAL FARMERS WITH LOW, INTERMEDIATE, AND HIGH EXPOSURE TO ORGANOPHOSPHOROUS CONTAINING AGROCHEMICALS

Organophosphorous containing agrochemicals (OCAs) are commonly used by farmers to prevent destruction of farm products by pests and weeds. Their role as risk factors of kidney disease is currently being evaluated. Blood acetylcholinesterase inhibition is a recognized marker of exposure to organophosphorous containing chemicals. We conducted a study to determine the proportion of rural farmers who use these agents, their blood acetylcholinesterase activities and comparative estimated glomerular filtration rate (eGFR) in those with low, intermediate, and high exposure. A cross-sectional study of nine rural farming communities in Southwestern Nigeria. Degree of exposure was categorized using the following criteria: (a) Years of active farming - Low (0-10 years) and High (> 10 years), (b) Use of protective garment - Low (Yes), High (No). A score of low for both parameters was categorized as low exposure, a score of low and high in both parameters was graded as intermediate exposure, while a score of high in both parameters was graded as high exposure. All participants were evaluated for kidney function using CKD-EPI equation to calculate the eGFR. Blood acetylcholinesterase activity was evaluated by the modified Ellman’s method. Five hundred and seventy two farmers participated in the study. Two hundred and twenty five (39.3%) were males while 347 (60.7%) were females. Mean age of participants was 52 ± 17.5 (range 18 – 100) years. Years of active farming ranged from 0.5 to 80 years, with a median of 25 years. Blood acetylcholinesterase activity ranged from 0 – 20.1 (mean 3.5 ± 3.5) µmol/min/mL in all participants. Four hundred participants (69.9%) stated that they used organophosphate containing agrochemicals. Exposure was low in 32 (8%), intermediate in 161 (40.6%), and high in 200 (50%) of these participants. Blood acetylcholinesterase activities / eGFR levels in low, intermediate, and high exposures are shown in the table. Statistically, blood acetylcholinesterase activities were similar in those with high compared to those with low exposure (P = 0.338). However, eGFR was significantly lower in those with high compared to those with low exposure (P = 000). Use of organophosphate containing agrochemicals was high in the rural farmers examined. There was a decline in eGFR with higher exposure. However, blood acetylcholinesterase activity levels did not appear to differ significantly among the different groups of exposure studied. There is a need for a prospective study to determine the normal range of blood acetylcholinesterase levels in unexposed individuals to define the minimum duration of exposure to organophosphate agrochemicals neccessary for significant surpression of blood of acetylcholinesterase levels in the rural farmers.

Effects of Phytochemicals on Blood Pressure and Neuroprotection Mediated Via Brain Renin-Angiotensin System.

Background: The renin-angiotensin system (RAS) in the brain plays a crucial role in maintaining blood pressure as well as neuroprotection. This study compared the effects of curcumin, quercetin, and saponin on blood pressure, the brain RAS, and cholinergic system using perindopril, an angiotensin converting enzyme inhibitor (ACEI), as a positive control. Methods: Five-week-old male mice were stabilized and randomly assigned into a control group (n = 8), three phytochemical-treated groups (curcumin (n = 8), quercetin (n = 8), and saponin (n = 8)), and a positive control group (n = 8). The groups treated with the phytochemical were orally administered daily at a dose of 50 mg/kg body weight of phytochemicals. During the experiments, the weight and dietary intakes were measured regularly. After experiments, the brain tissue was homogenized and centrifuged for an additional assay. The concentrations of ACE, angiotensin II (AngII), and aldosterone levels were measured, and the mRNA expressions of renin and ACE were measured. As biomarkers of neuroprotection, the concentrations of acetylcholine (ACh) as well as the concentration and activity of acetylcholine esterase (AChE) were measured. Results: After 4 weeks of treatment, the perindopril group showed the lowest blood pressure. Among the groups treated with the phytochemicals, treatment with curcumin and saponin significantly reduced blood pressure, although such effect was not as high as that of perindopril. Among phytochemicals, curcumin treatment significantly inhibited the concentration and activity of ACE, concentration of AngII, and mRNA expression of ACE. All phytochemical treatments significantly increased the concentration of ACh. The levels of AChE activity in groups exposed to curcumin or saponin (not quercetin) were significantly inhibited, Conclusion: Curcumin administration in rats reduced blood pressure by blocking the brain RAS components and protected the cholinergic system in brain by inhibiting the activity of AChE.

Biomonitoring of blood cholinesterases and acylpeptide hydrolase activities in rural inhabitants exposed to pesticides in the Coquimbo Region of Chile.

In Chile, agriculture is a relevant economic activity and is concomitant with the use of pesticides to improve the yields. Acute intoxications of agricultural workers occur with some frequency and they must be reported to the surveillance system of the Ministry of Health. However the impacts of chronic and environmental pesticide exposure have been less studied. Among pesticides frequently used in Chile for insects control are organophosphates (OP) and carbamates (CB). They are inhibitors of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). In this study we determined the pattern of both biomarkers activity in three populations with different type of chronic exposure to OP/CB: environmentally exposed (EE), occupationally exposed (OE) and a reference group (RG) without exposure. Besides this, we also measured the activity of acylpeptide hydrolase (APEH), an enzyme involved in relevant functions in the central synapses that is also expressed in erythrocytes and previously reported to be highly inhibited by some OP. A baseline measurement was done in both exposure groups and then a second measurement was done during the spraying season. The RG was measured only once at any time of the year. Our results indicate that people under chronic OP/CB exposure showed an adaptive response through an increase of basal BChE activity. During the spray season only BChE activity was decreased in the EE and OE groups (p<0.05 and p<0.01, respectively) and the higher magnitude of BChE inhibition was observed in the EE group. The analysis of the frequencies of inhibition above 30% (biological tolerance limit declared by Chilean legislation) indicated that BChE was most frequently inhibited in the EE group (53% of the individuals displayed inhibition) and AChE in the OE group (55% of the individuals displayed AChE inhibition). APEH activity showed the highest frequency of inhibition in the EE group independent of its magnitude (64%). Our results demonstrate that the rural population living nearby agricultural settings displays high levels of environmental exposure. APEH activity seems to be a sensitive biomarker for acute low-level exposure and its usefulness as a routine biomarker must to be explored in future studies. Systematic biomonitoring and health outcomes studies are necessary as well as obtaining the baseline for BChE and AChE activity levels with the aim to improve environmental and occupational health policies in Chile.

The Role of Acetylcholine Esterase in Resistance Mechanism of Plutella xylostella to Emamektin Benzoate

One of the resistance mechanism of P. xylostellato emamektin benzoate is target insensitivity which is acetylcholine esterase that responsible for resistance occurrence. The objective of this study was to determine the role of acetylcholinesterase in the resistance mechanism of P. xylostella population to emamektin benzoate. For enzyme activity analysis, larvae homogenate of the third instar of P. xylostella was prepared. The number of insects required for each scour is 1 for each field population. The protein content in P. xylostella homogenate was measured by the Folin-Ciocalteu test. Non-specific esterase activity with an absorption rate was read using ELISA reader tool with λ = 450 nm. The inhibition level of acetylcholinesterase activity by emamectin benzoate in the tested population was 36.84%. The highest inhibition occurs in Puasan (Ngablak) population. The result shows that a α-naphthyl acetate substrate was used so that it was recorded as non-specific esterase activity and did not exhibit esterase activity which specifically describes emamectin benzoate. Non-specific esterase enzyme activity of either α or β-naphthyl acetate substances to benzoic emamectin in the tested population most of the population was still susceptible. On α-naphthyl acetate substrate, the highest absorbance value found in susceptible population to benzoate emamectin (0.773), while the lowest found in Babrik (Ngablak) population (0.083).

Enhanced cholinergic-tone during the stress induce a depressive-like state in mice

Major depressive disorder has a heterogeneous etiology, since it arises from the interaction of multiple factors and different pathophysiological mechanisms are involved in the symptomatology. This study aimed to investigate the role of the cholinergic system in the susceptibility to stress and, consequently, in the depression-like behavior. C57BL/6 mice were treated with Physostigmine (PHYS), an acetylcholinesterase (AChE) inhibitor, and were submitted to the social defeat stress. For the behavioral evaluation of the locomotor activity, anxiety-like and depression-like behaviors the open field, elevated plus maze, sucrose preference, social interaction and forced swim were used. Hippocampus and prefrontal cortex samples were collected for evaluation of AChE activity, as well as blood samples for analysis of serum cortisol levels. Our results showed that 15 min after the injection of PHYS there was a significant inhibition of AChE activity in the hippocampus and in the prefrontal cortex. On the other hand, in the end of the experimental design, day 12, there was no difference in AChE activity levels. Inhibition of AChE and exposure to the stress led to an increase in cortisol levels. Animals that received PHYS and were exposed to stress showed less social interaction and greater learned helplessness, anhedonia and anxious-like behavior. Taken together, our findings suggest that increasing the cholinergic tone shortly before stress induction impacts on the ability to cope with upcoming stressful situations, leading to a depressive-like state.

Behavioral and neurochemical consequences of perinatal exposure to lead in adult male Wistar rats: protective effect by Centella asiatica.

The present study evaluated the protective effects of Centella asiatica (CA) leaf extract on behavioral deficits and neurotoxicity in adult rat exposed to lead during perinatal period. Adult Wistar rats were exposed to 0.15% lead acetate (Pb) from gestation day 6 through drinking water and the pups were exposed lactationally to Pb till weaning. Significant perturbations in locomotor activity and exploratory behavior were observed in rats exposed to Pb during perinatal period. The levels of lipid peroxidation increased significantly with a reduction in levels of glutathione and activity levels of acetylcholinesterase and antioxidant enzymes in hippocampus, cerebrum, cerebellum, and medulla of brains excised from Pb-exposed rats. Oral supplementation of CA during postweaning period provided significant protection against Pb-induced behavioral impairments and neurotoxicity, without chelating tissue Pb levels. The possible neuroprotective efficacy of CA may be due to its antioxidant potential but not by lowering effects of brain Pb content.

Evaluation of multiwalled carbon nanotubes toxicity in two fish species

Carbon Nanotubes are among the most promising materials for the technology industry. Their unique physical and chemical proprieties may reduce the production costs and improve the efficiency of a large range of products. However, the same characteristics that have made nanomaterials interesting for industry may be responsible for inducing toxic effects on the aquatic organisms. Since the carbon nanotubes toxicity is still a controversial issue, we performed tests of acute and subchronic exposure to a commercial sample of multiwalled carbon nanotubes in two fish species, an exotic model (Danio rerio) and a native one (Astyanax altiparanae). Using the alkaline version of the comet assay on erythrocytes and the piscine micronucleous, also performed on erythrocytes, it was verified that the tested carbon nanotubes sample did not generate apparent genotoxicity by means of single/double DNA strand break or clastogenic/aneugenic effects over any of the species, independently of the exposure period. Although, our findings indicate the possibility of the occurrence of CNTs-DNA crosslinks. Apparently, the sample tested induces oxidative stress after subchronic exposure as shown by activity of superoxide dismutase and catalase. The data obtained by the activity levels of acetylcholinesterase suggests acute neurotoxicity in Astyanax altiparanae and subchronic neurotoxicity in Danio rerio.

"Crocin, a Carotenoid Mitigates Acrylamide Induced Phenotypic Alterations, Oxidative Stress and Dopaminergic Neurodegeneration in Caenorhabditis Elegans: Implications for Neuropathy

Earlier we demonstrated the potential of Crocin, (CR) a well known carotenoid to attenuate experimentally induced neurotoxicity employing a Drosophila model. In the present study we sought to obtain insights on the neuroprotective propensity of CR using acrylamide (ACR) model of neurotoxicity in the nematode, Caenorhabditis elegans. We exposed age-synchronized L4 worms (both wild-type N2 and BZ555 strain to ACR (250mg/L) for 48 h in the presence or absence of CR (10µM). The protective efficacy of CR was assessed in N2 worms by analyzing phenotypic alterations (locomotory behaviour), reproductive functions (brood size and egg laying), biochemical parameters and longevity. The neuroprotective propensity was assessed by direct visualization and quantification of dopaminergic (DA) neurons in the transgenic strain (BZ555). CR treatment not only normalized reproductive functions, but significantly alleviated ACRinduced oxidative stress and mitochondrial dysfunction. Further, CR restored the activity levels of acetylcholinesterase, dopamine levels and markedly reduced the dopaminergic degeneration. CR also extended the lifespan in N2 worms and markedly enhanced the expectancy of short-lived mutant worms (MEV-1). Collectively, these experimental findings reveal that CR significantly attenuates the dopaminergic neurodegeneration and associated physiological/ biochemical dysfunctions induced by ACR in C. elegans. Based on these data we propose that Crocin may be an effective therapeutic adjuvant in the management of oxidative stress mediated neurodegenerative conditions.

Prevalence of chromosomal aberrations in Argentinean agricultural workers

Little is known about biosecurity measures and toxic effects during pesticide application in the province of Jujuy, Argentina, particularly concerning the protective measures and mixture of pesticides used by rural workers. We carried out an observational study of agricultural workers from Jujuy (76 exposed subjects and 53 controls) to investigate the prevalence of chromosomal aberrations (CAs) in human lymphocytes as well as the activity level of acetylcholinesterase (AChE) in red blood cell erythrocytes. Whole blood samples (5mL) were collected in heparinized Vacutainer tubes for cytogenetic analysis and erythrocyte cholinesterase activity determination according to Ellman's method. Cytogenetic results showed a significant CA increase in pesticide-exposed individuals as compared with controls (4.20±0.15 vs. 1.00±0.05, respectively; p<0.001), suggesting that pesticides are clastogenic agents causing DNA damage. Erythrocyte cholinesterase activity was significantly lower in exposed individuals, evidencing the possible occurrence of perturbations in blood as well as neurotoxicity in pesticide sprayers. These results suggest the need for periodic biomonitoring of these biomarkers together with education and training of occupational workers for the safe application of potentially harmful pesticides.

Evaluating Diagnostic Value of Electrophysiological Testing (EMG-NCV) Compared to the Activity Level of Acetylcholinesterase in Serum and Red Blood Cells of Patients with Moderate to Severe Organophosphate Poisoning

Abstract Background: Organophosphate compounds cause poisoning and death more than any other insecticide. These toxins can cause peripheral neuropathy which is delayed for about 3 - 6 weeks and no method has been known for predicting the incidence. It has been claimed that electrophysiological tests (EMG - NCV) can help in predicting the disorder. Objectives: The main purpose of this research was to study EMG - NCV tests in patients with moderate to severe organophosphate poisoning. Methods: This was a cross-sectional study conducted on patients with moderate to severe organophosphate poisoning from 2014 to 2016 in Imam Reza hospital of Mashhad. The minimum sample size was calculated as 68 patients and then all data was collected on the basis of inclusion and exclusion criteria using data collection form designed by the researcher, and finally data were analyzed using SPSS V.21 software, descriptive tests (including mean, median, mode) and analytical tests (K square, ANOVA). Results: Of all 78 patients with the mean age of 27.5010.0, 45 were female and the rest were male. Totally 29.5% of the patients had abnormal EMG - NCV. Although no significant differences were observed between electro diagnostic tests (EMG - NCV) and age, gender, clinical symptoms and levels of acetylcholinesterase serum activity, the relationship between EMG - NCV and RBC levels of acetylcholinesterase activity was significant. Conclusions: Electrophysiological tests are not associated with clinical symptoms (muscle weakness) and they cannot be considered as a determining factor to discharge the patients; therefore, careful examination of the patients or evaluating the level of AChE activity in red blood cells is needed.