Erythrocyte Cholinesterase Activity Research Articles

Evaluation of Changes in Acetylcholinesterase Activity in Workers of Mehriz Elixir Pesticide Plant in Yazd

Background and Aims: Some pesticide chemical compounds, such as organophosphates and carbamates, interfere with or inhibit cholinesterase activity. Employees working in pesticide factories are one of the groups at risk of pesticide poisoning. This study aimed to evaluate the effect of work on exposure to toxins on the serum level of erythrocyte cholinesterase activity.
 Materials and Methods: This research was conducted on Mehriz Elixir Pesticide Factory workers. Blood samples were taken from 76 employees in 2 groups as a control group, and 38 workers were exposed to organophosphorus toxins three months after starting work in a factory. Cholinesterase activity was analyzed using the Elman method, and data were analyzed using SPSS software version 22.
 Results: The mean age of the subjects was 35.07 years, which was 35.26 in the exposure group (n = 38) and 34.89 in the control group (n = 38). The activity of acetylcholinesterase enzyme in the control group at 0, 10, and 20 minutes was 12.78 ku/l, 14.24 ku/l, and 15.45 ku/l, respectively. The acetylcholinesterase enzyme activity in the exposed group was 10.77 ku/l, 10.40 ku/l, and 10.36 ku/l at 0, 10, and 20 minutes, respectively. At all stages, the mean acetylcholinesterase activity in the control group was higher than the exposed group, but significant differences were observed at 10 and 20 minutes between the 2 groups.
 Conclusion: Exposure of workers to organophosphate inhibits acetylcholinesterase, which manifests by a decrease in the activity of this enzyme.

Changes in blood oxidative stress biomarker and cholinesterase activity after general vs spinal anesthesia for elective cesarean sections

Background & Objective: There is an increased ratio of cesarean sections (CS) compared to normal deliveries the world over. Both general and regional anesthetic techniques are in practice for CS. Limited information is available on the determination of blood cholinesterase (ChE) activity in conjunction with oxidative stress biomarkers after the CS. The purpose of the present study was to determine and compare the plasma and erythrocyte ChE activity as well as malondialdehyde (MDA) level and total antioxidant status in pregnant women before anesthesia and after the use of general anesthesia (GA) or spinal anesthesia (SA) for elective CS.
 Methodology: A pre-post study was conducted on 102 full-term pregnant women, who underwent elective CS in four hospitals at Duhok (Iraq) from January 2022 to July 2022. GA with propofol and SA with bupivacaine 0.5% were administered to 52 and 50 women, respectively. Maternal blood samples before anesthesia and after the completion of operation were assayed for the ChE activity in the plasma and erythrocytes, and plasma oxidative stress biomarkers malondialdehyde and total antioxidant status.
 Results: Plasma ChE activity significantly decreased in the GA and SA groups after the cesarean-deliveries compared to the corresponding pre-anesthetic values. The plasma MDA level in both GA and SA groups, but not the total antioxidant status, was significantly reduced. Estimation of the odds ratio and the relative risk indicated that a risk factor is associated with the reduced plasma ChE activity in women after the CS when the general anesthetic propofol is used.
 Conclusion: Both general anesthesia with propofol and spinal anesthesia with bupivacaine inhibited plasma cholinesterase activity and reduced oxidative stress biomarker malondialdehyde after the cesarean sections.
 Abbreviations: CS - Cesarean section; ChE: Cholinesterase; EChE: Erythrocyte Cholinesterase; MDA: Malondialdehyde; OS: Oxidative Stress; PChE: Plasma ChE; TAS: Total Antioxidant Status.
 Key words: Anesthesia, Spinal; Cesarean section; General anesthesia; Malondialdehyde; Oxidative stress
 Citation: Karam RS, Mohammad FK. Changes in blood oxidative stress biomarker and cholinesterase activity after general vs spinal anesthesia for elective cesarean sections. Anaesth. pain intensive care 2023;27(3):396−404; DOI: 10.35975/apic.v27i3.2244
 Received: March 23, 2023; Reviewed: May 06, 2023; Accepted: May 09, 2023

In vitro Inhibition of Human Plasma and Erythrocyte Cholinesterases by a Selected Drugs (Enzymes Inhibitors)

The inhibitory effect for human plasma and erythrocyte cholinesterase activity by six drugs already known as an enzyme inhibitors (Cimetidine, Ciprofloxacin, Donepezil, Sildenafil, Erythromycin, and Chlorpheniramine) was tested in vitro. The affinity toward the cholinesterase system was evaluated by using different concentrations of the investigated drugs. The cholinesterase activities were determined by using the modified electrometric method. Each drug showed different ability to inhibit cholinesterase activity depending on its concentration and its selectivity to the either plasma or erythrocyte cholinesterase; only Donepezil and Chlorpheniramine showed higher inhibitory effect. Ciprofloxacin showed moderate inhibition of cholinesterase but still statistically insignificant. Cimetidine, Sildenafil and Erythromycin showed little inhibitory activity although they have a good inhibitory effect on the liver enzyme system Cytochrome P450 (CYP450 ).

Blood cholinesterase activities and oxidative stress status among farmworkers using pesticides in Duhok, KRG, Iraq

Background: The use of pesticides by farmworkers poses considerable health risks. This study was undertaken to examine plasma and erythrocyte cholinesterase activities, plasma oxidative biomarkers malondialdehyde (MDA), and total antioxidant status (TAS) among farmworkers using different pesticide products in Duhok, northern of Iraq. Methods: This is a case-control study conducted between November 2021 to July 2022 on 92 male farmworkers who were exposed to pesticides in comparison with 44 non-exposed male subjects (control). The availability and uses of pesticides were obtained from 19 agrochemical shops and the farmworkers exposed to pesticides. Demographic data of pesticide-exposed farmworkers and their practice of pesticide applications were recorded. Plasma and erythrocyte cholinesterase activities and plasma MDA and TAS levels were determined in both groups. Results: The farmworkers had a significant 10.0% increase in plasma MDA level, with no significant changes in blood cholinesterase activities or the TAS level. Odds and risk ratios of reduced plasma cholinesterase activity (20.0%) suggested an association of health risks in pesticide-exposed farmworkers. Most of the pesticide products (278) in use were insecticides (47.0%), which comprised mainly 26.0% pyrethroids and 3.0-7.0% anticholinesterase insecticides, among others. The majority of the farmworkers (51%) were merely aware of the general target use of the pesticide, and 75% had an exposure history of > 5 years. Pesticide application was mostly (50.0%) manual, and 54.0% used insufficient personal protection equipment; 32.0% ate and drank at work, 48.0% practiced disposal of empty pesticide containers by burning and/or burying them, whereas 25.0% dumped the containers indiscriminately, and 25% disposed them at garbage sites openly. Conclusion: The farmworkers, with only a marginal increase in oxidative stress biomarker MDA, did not suffer from significant reductions in blood cholinesterase activities, although odds and risk ratios of reduced plasma cholinesterase activity suggested a health risk. Implementation of a national program is needed to measure pre-exposure blood cholinesterase activities in farmworkers.

MONITORING BLOOD CHOLINESTERASE ACTIVITY OF FARMWORKERS: IN VITRO INHIBITION BY DIPHENHYDRAMINE AND CARBARYL

Plasma and erythrocyte cholinesterase (ChE) activities of male farm workers exposed to pesticides during their routine work were lower than those of unexposed control subjects by 14 and 4%, respectively. Diphenhydramine and Carbaryl inhibited plasma and erythrocyte ChE activities in vitro in pesticide-exposed and unexposed subjects. The percentages of in vitro ChE inhibition induced by carbaryl in the plasma and erythrocytes of unexposed controls ranged between 47-85% and 19-47%, respectively, whereas they were 35-60% and 3-12% in the pesticide-exposed group, respectively. In vitro pretreatment of plasma and erythrocyte ChE with diphenhydramine (20 μM) significantly reduced the inhibitory effect of carbaryl (10 μM) on them by 18% and 10%, respectively. In conclusion, subjects exposed to pesticides during their routine work in agriculture are at risk of reduced blood ChE activity. Diphenhydramine appeared to partially protect blood ChE in vitro from additional carbaryl-induced enzyme inhibition in both pesticide-exposed and unexposed subjects.

Poisoning Cases Reported to Poison Information Centre, Ahmedabad, India: A Three Year Observational Study.

Introduction:Morbidity and mortality associated with pesticide poisoning is a major public health issue, especially in lower and middle income countries, including India. Timely understanding of poisoning trends is required for improved prevention. The objective of the present study was to analyze the trend of poisoning cases in Ahmedabad, India in the period of 2015–2017.Methods:Detailed history, including demographic data, risk factors, poisoning history, agents involved, and occupational influence were collected for poisoning cases reported to the Poison Information Centre in Ahmedabad. Cholinesterase activity and HPTLC method for detection of sanguinarine in urine were used to investigate the agents of poisoning. Non-parametric tests, such as Chi-square test and Mann-Whitney U Test were applied to test statistical significance between the groups. All statistical analysis was carried out using IBM SPSS Statistics for Windows, Version 26.0. Armonk, NY: IBM Corp.Results:A total 1373 poisoning cases were investigated. The incidence and fatality rate was found to be higher in males compared to females (M/F ratio 1.89:1). About 91.62% of the poisoning were through the oral route. Erythrocyte cholinesterase activity assay results indicated that 41.29% of the cases were due to organophosphorus/carbamate poisoning. Insecticides were found to be the agent of poisoning in 26.29% cases, and 11.07% of all the cases were agricultural workers. Poisoning with medications, household pesticides and chemicals were also reported. Few cases of food poisoning with sanguinarine were detected.Conclusions:The data presented here suggest that pesticides used for agriculture are the major source of poisonings. Implementation of usage guidelines, educating farmers and vulnerable population, and finding novel alternatives for highly toxic chemicals may be helpful in decreasing the number of poisoning cases.

Hearing screening and cholinesterase activity among rural workers exposed to pesticides.

Agricultural activities and exposure to pesticides increase the risk of hearing loss and might reduce cholinesterase activity. To describe and analyze the correlation between hearing screening and plasma and erythrocyte cholinesterase activity relative to rural workers exposed to pesticides. Cross-sectional, quantitative, descriptive and explanatory study conducted with 71 rural workers exposed to pesticides. Data were collected by means of an instrument to characterize exposure to pesticides, hearing screening and blood samples to measure plasma and erythrocyte cholinesterase activity. Each participant used three different pesticides, on average, glyphosate being the most frequently mentioned. About 60.6% of the sample exhibited hearing abnormalities and 32.4% complained of tinnitus. Erythrocyte cholinesterase activity was within the normal range in all the cases; one single participant exhibited reduced plasma cholinesterase activity. There was not significant correlation between the hearing screening and cholinesterase levels. Audiological evaluation should be included in the assessment of rural workers. Monitoring workers exposed to pesticides should not be restricted to cholinesterase activity alone, because this method is insufficient to detect actual exposure to pesticides.

Cholinesterase Level in Erythrocyte or Serum: Which is More Predictive of the Clinical Outcome in Patients with Acute Organophosphate Poisoning?

Background: Acute organophosphate poisoning (AOPP) is related to several clinical complications that may be fatal. The aim of this study was to evaluate the effects of demographic, clinical and laboratory findings on AOPP outcome. Methods: In this retrospective cross-sectional study, medical records of all patients with AOPP admitted to Imam Reza Hospital, Mashhad, Iran, were reviewed from January 2016 to December 2017. Demographic data, clinical presentations, erythrocyte cholinesterase (RBC-ChE) and serum cholinesterase (S-ChE) activities were studied and evaluated in relation to clinical outcome of the patients. Results: A total of 64 patients (37 male, 27 female) were evaluated from whom 6 patients (9.4%) died. Statistically significant relationships were found between the outcome of the patients and RBC-ChE activity (p =0.008), intratracheal intubation (p=0.003), and abnormal blood pressure (p =0.009). Despite the lower mean S-ChE levels in the deceased patients and loss of consciousness in 42.2% (n=27) of patients, there was no statistically significant correlations between these factors and patients’ outcome (p =0.147, p =0.075, respectively). Conclusion: RBC-ChE activity, need for intratracheal intubation, and abnormal blood pressure on admission were important predictive factors in the clinical outcome of AOPP. Although S-ChE activity, level of consciousness, white blood cell count and blood glucose level on admission provide useful information, these data had no prognostic value in patients with AOPP.

Prognostic Significance of Creatine Phospokinase (CPK) Levels in Assessing the Severity of Organophosphorus Poisoning Compound Poisoning

Organophosphorus poisoning (OP poisoning) is common poisoning specially in developing countries like India. This compound is easily available, cheap and is used in agricultural field as pesticides. Both accidental and suicidal poisoning has been reported. Laboratory parameters like erythrocyte cholinesterase activity has been used to support clinical diagnosis and to predict prognosis and it is costly. Pseudocholinesterase is cheaper alternative but it is less reliable. There are few other biochemical markers including CPK which is usually raised in cases of acute OP poisoning and it is a cheaper investigation and is easily performed in all laboratories. Hence this study was done to evaluate role of creatine phosphokinase levels to support clinical diagnosis as well as predicting prognosis in acute OP compound poisoning. Materials and Methods: It was a prospective observational study which included 50 patients who presented within 6 hours of consumption of OP compound afterconsidering inclusion and exclusion criteria. Patients were categorized into mild, moderate and severe poisoning according to POP score and initial CPK levels were noted. Data expressed in percentages and chi-square test was used to know statistical significance. Results: Out of 50 patients, 28 (56%)had mild, 16 (32%) had moderate and 6 (12%) had severe poisoning. Initial CPK levels were positively correlated with POP score. Four deaths occurred in our studyout of which one had moderate poisoning and threehad severe poisoning. Conclusion: Initial CPK levels correlated with severity of OP compound poisoning and mortality.

Interaction between polymorphisms in cell-cycle genes and environmental factors in regulating cholinesterase activity in people with exposure to omethoate.

Cholinesterase activity (ChA), the effective biomarker for organophosphate pesticide exposure, is possibly affected by single nucleotide polymorphisms (SNPs) in cell-cycle-related genes. One hundred and eighty workers with long-term exposure to omethoate and 115 healthy controls were recruited to explore the gene–gene and gene–environment interactions. The acetylthiocholine and dithio-bis-(nitrobenzoic acid) method was used to detect the cholinesterase activities in whole blood, erythrocytes and plasma. Genetic polymorphisms were determined by the PCR-RFLP and direct PCR electrophoresis methods. Statistical results showed that the cholinesterase activities of whole blood, erythrocytes and plasma in the exposure group were significantly lower than those in the control group (p < 0.001), and erythrocyte cholinesterase activities were associated with gender, smoking and drinking in the exposure group (p < 0.05). Single-locus analyses showed that there is a statistically significant difference in the ChA among the genotypes CC, CA and AA of the p21 rs1801270 locus in the control group (p = 0.033), but not in the exposure group. A significant interaction between genes and environmental factors (i.e. p53, p21, mdm2, gender, smoking and drinking) affecting ChA was found through a generalized multifactor dimensionality reduction analysis. These obtained markers will be useful in further marker-assisted selection in workers with exposure to omethoate.

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 the protective effects of vitamin C on serum and erythrocyte cholinesterase activity of male rats exposed to malathion.

IntroductionMalathion is one of organophosphate poisons (OPPs) that inhibit cholinesterase activity and induce oxidative stress in target organs, such as the reproductive system. The aim of this study was to assess the effects of Malathion on serum and erythrocyte cholinesterase activity in male rats and also to assess the protective effects of vitamin C in this regard.MethodsThis experimental study was performed in the Pharmacology Laboratory of the Pharmacy Faculty and in the Advanced Histology Techniques Laboratory of the Medical Faculty of Mashhad University of Medical Sciences (MUMS) in January 2014. Thirty male wistar rats, weighting 200–250 g, were divided into five groups of six. The different groups were exposed as follows: group 1: Malathion 50 mg/kg; group 2: Vitamin C; group 3: Malathion plus Vitamin C with the specified doses; sham group: normal saline; and control group: no exposure. After six weeks, 3 ml blood samples were taken from the rats, and titrimetric and Ellman methods were used to assess serum and erythrocyte cholinesterase activity, respectively. The data was analyzed by SPSS 16, and p < 0.05 was considered significant.ResultsThe activities of serum and erythrocyte cholinesterase were inhibited significantly in the Malathion exposed group compared to the control group (p < 0.001). The administration of Vitamin C alone significantly increased the activities of serum and erythrocyte cholinesterase. The serum and erythrocyte cholinesterase inhibition showed improvement in the group that received both Malathion and Vitamin C.ConclusionMalathion reduced the activities of serum and erythrocyte cholinesterase in exposed animals. It probably has the same intoxication effects on people who are exposed. Improvement of cholinesterase activity by antioxidant effects of Vitamin C suggests that Vitamin C supplementation can be used to decrease side effects of OPP exposure.

Evaluation of chronic intoxication by organophosphate insecticides among hygiene workers in the city of Fez, Morocco

Summary Context of the study The use of pesticides in the field of public health involves a risk for both humans and the environment. Objective The purpose of this study, carried out for the first time in the center of Morocco, was to evaluate chronic intoxication by organophosphate insecticides. This was done through the evaluation of cholinesterase activity as a biomarker of pesticide intoxication among a population of hygiene workers who daily handled these products, in six districts of the city of Fez. Method This study is a descriptive cross-sectional study including 30 consenting hygiene workers carried out during a period of 4 months (February-May 2015). The study included a physical examination and biotoxicological measurements: plasma and erythrocyte acetylcholinesterase activity. Erythrocyte acetylcholinesterase activity was determined by spectrophotometric method at ambient laboratory temperature (25 °C) using the kit “Test Mat - model 400”. Results Twenty-nine subjects of the studied population were of male gender with an average age of 48 ± 8 years and a body mass index of 25.67 ± 2.09 kg/m 2 ; and only one subject was of female gender aged 56, and a body mass index of 26.25 kg/m 2 . The somatic clinical examination of the participants in this study revealed neither serious clinical history nor cases of pesticide poisoning. The mode value of erythrocyte cholinesterase activity was 54, and that of plasmatic cholinesterase activity was 65. The measured cholinesterase activity is not correlated with age but it is correlated with the body mass index. Three cases showed a decrease in cholinesterase activity of the order of (35%, 36%, and 25%) compared to 30% as recommended by the World Health Organization. Conclusion These results relating to the determination of cholinesterase activity, although preliminary, should reassure the exposed persons and the authorities concerned without neglecting the systematic control of the three cases detected. The use of organophosphates in the field of public health requires regular checking, precautions, and training of the hygiene workers to avoid any serious health risk.

Establishing the Cholinesterase Levels in Jordan : An Investigation and Monitoring Model for Pesticides Outbreak = تحديد مستوى الكولين أستريز في الأردن : نموذج تقصي و رصد لحدوث انتشار التسمم بالمبيدات

Background Aims: To establish and validate the method used to analyze cholinesterase in blood and to establish a baseline level among Jordanians living in a heavy agricultural activity area and as well as among those living in an urban non-agricultural area. Materials and Methods: Modified Ellman procedure was used to analyze 851 and 1033 blood samples from heavy agricultural activity and urban area for cholinesterase activity in erythrocytes and Plasma. Results: sample collected from heavy agricultural activity showed low cholinesterase level average 1037U/L ± 279 and 23 U/gHb ± 7.9 compared with urban area average 1616 U/L ± 662 and 31 U/gHb ± 13 for plasma and erythrocyte respectively. The levels in workers living in heavy agriculture activity showed 52% inhibition in plasma and 41.1% in erythrocyte when compared to the established normal levels that were observed in urban area. Conclusions: Clinicians using cholinesterase for clinical diagnosis and management should be aware that baseline levels are different according to the residence of their patients.

Cholinesterase Research Outreach Project (CROP): measuring cholinesterase activity and pesticide use in an agricultural community.

BackgroundAustralian farmers and their workers are exposed to a wide variety of pesticides. Organophosphate (OP) insecticides are a widely used class of pesticide used for animal husbandry practices (Naphthalophos for sheep dipping, jetting and drench), crop production for pest control (Dimethoate) and in public health (Maldison for head lice). Acute poisonings with this class of insecticide are reported among agricultural workers and children around the globe, due to the inhibition of acetylcholinesterase (AChE). Less is known about chronic exposures. Regular monitoring of erythrocyte AChE will enable farmers to identify potential exposure to organophosphate insecticides and take action to reduce exposures and improve their health and safety practices. This study aims to assess and improve the integration of AChE monitoring into routine point of care health clinics, and provide farming and non-farming people with a link between their AChE activity and their household chemical and agrichemical use.Methods/DesignThe research will target individuals who work on mixed farming enterprises and routinely using OPs (n = 50) and non-farmers (n = 30). Baseline data are collected regarding demographic, health conditions and behaviours, Kessler 10 (K10) scores, chemical use and personal protection. Baseline anthropometric measures include height, weight, hip and waist circumference, body fat analysis and, biochemical analysis of fasted total serum cholesterol, triglycerides, low-density cholesterol (LDL), high-density cholesterol (HDL) and blood glucose. Analysis of erythrocyte cholinesterase (EAChE) activity is also conducted using a finger prick test. Testing of EAChE is then repeated in all participants every 3 weeks for a maximum of three times over a period 10 weeks. Participants are provided with full feedback and counselling about their EAChE activity after each reading and a detailed summary provided to all participants at the completion of the study. Data will be analysed using repeated measures within a general linear model.DiscussionThis work will provide an evidence base and recommendations for the integration of EAChE monitoring into Australian rural health clinics, leading to research which will further quantify pesticide exposure both on the farm and in the home, highlighting the importance of sustaining and providing a safe work and home environment for farming communities.Trial registrationACTRN12613001256763

Pesticide exposure and genetic variation in xenobiotic-metabolizing enzymes interact to induce biochemical liver damage

Metabolic activation of pesticides in the liver may result in highly reactive intermediates capable of impairing various cellular functions. Nevertheless, the knowledge about the effect of pesticide exposure on liver function is still limited. This study assessed whether exposure to pesticides elicits early biochemical changes in biomarkers of liver function and looked for potential gene-environmental interactions between pesticide exposure and polymorphisms of pesticide-metabolizing genes. A longitudinal study was conducted in farm-workers from Andalusia (South Spain), during two periods of the same crop season with different degree of pesticide exposure. Blood samples were taken for the measurement of serum and erythrocyte cholinesterase activities as well as for determining clinical chemistry parameters as biomarkers of liver function. Serum lipid levels were also measured as they may help to monitor the progress of toxic liver damage. A reduction in serum cholinesterase was associated with decreased levels of all clinical chemistry parameters studied except HDL-cholesterol. Conversely, a decreased erythrocyte cholinesterase (indicating long-term pesticide exposure) was associated with increased levels of aspartate aminotransferase and alkaline phosphatase and increased levels of triglycerides, total cholesterol and LDL-cholesterol, but reduced levels of HDL-cholesterol. Changes in liver biomarkers were particularly associated with the PON155M/192R haplotype. The obtained results therefore support the hypothesis that pesticide exposure results in subtle biochemical liver toxicity and highlight the role of genetic polymorphisms in pesticide-metabolizing enzymes as biomarkers of susceptibility for developing adverse health effects.

In vitro kinetic study of donepezil N- oxide metabolites

Objective: The aim of this study was to examine the metabolism of donepezil via N – oxidation of donepezil HCl in vitro, and the kinetic studies at a temperature similar to that of the human body. Methods: Direct reaction of donepezil with hydrogen peroxide and formic acid at room temperature, the N – oxide undergoes a series of rearrangements, the reaction was followed by ultraviolet at λmax= 268 nm at 37 °C. The donepezil N- oxide was also tested as potential cholinesterase inhibitor using electrometric for cholinesterase determination. Results: According to the present work , the structure of donepzil N- oxide was elucidated using spectroscopic analysis , also , in vitro kinetic study at 37 °C using ultraviolet spectrophotometer at λmax = 268 nm showed that the reaction proceeded at a first order reaction . Biologically, the compound was found to inhibit both plasma and erythrocyte cholinesterase activities in vitro .. Conclusion: We concluded that the N- oxide of denepezil undergoes a series of rearrangements, the reaction followed first order at 37 °C. It has a potential anticholinesterase activity

Influence of physical exercise and gender on acetylcholinesterase and butyrylcholinesterase activity in human blood samples

The determination of cholinesterase activity in plasma and erythrocytes serves as a useful and sensitive biomarker of exposure to organophosphorus and carbamate pesticides. However, acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) activity may be influenced by factors such as age, gender, drugs, and physical exercise. The aim of this study was to evaluate the effects of gender and physical exercise on the activity of AChE and BuChE in healthy individuals. The values for both enzymes were lower for women. Physical exercise increased the levels of BuChE, and had no significant effect on AChE. To our knowledge, this is the first clinical study evaluating the influence of physical exercise in levels of these enzymes. Considering that cholinesterase activity is a useful parameter in assessing the exposure of individuals to pesticides, it is important to understand factors that influence the determination of the enzymes in order to avoid the erroneous interpretation of results.

Toxicological evaluation and bioavailability of 14C-fenitrothion bound residues on soybeans towards experimental animals

Under local practice of Egyptian conditions, the application of 14C-fenitrothion on soybeans at a dose of 10 mg insecticide/kg grains, led to the formation of 21% of 14C-bound residues (non-extractable) after 24 weeks of storage. The external residues were 20% and the internal extracts were 55% of the applied dose. Feeding studies on rats revealed that bound residues were bioavailable. After feeding rats for three days with bound 14C-fenitrothion residues, the main portion of radioactivity was eliminated via expired air (42%), urine (20%) and feces (11.5%). About 15% of the administered radioactivity was distributed among various organs as, liver, kidney, lung, fat, intestine, blood, heart, and brain. Toxicity of bound residues of 14C-fenitrothion in stored soybeans was studied in mice through feeding experiments for three months at a concentration of 1.9 mg/kg. The maximum inhibition in plasma and erythrocyte cholinesterase activity was observed 22.5%, 18.9% and 8.6%, 9% after one and seven days, respectively. The obtained results showed a slight significant elevation after three months in the activity of liver enzymes alanine amino transferase, aspartate amino transferase and alkaline phosphatase. A moderate increase in blood urea nitrogen and creatinine concentration was observed in the treated groups at the end of the experimental period. The detected levels of albumin and total protein showed no significant compared to the control values, of controlled animals, after three months.

Acute toxicity of Nerium oleander aqueous leaf extract in rabbits

The median lethal dose was evaluated in rabbits subcutaneously injected with Nerium oleander aqueous leaf extract . The clinical signs , postmortem changes , hematological and biochemical changes were recorded. The results revealed that the median lethal dose was 157.37 mg / kg B. wt. The live animals showed nervous signs in the second days after treatment as crying, ataxia , abdominal respiration , inaddition to a significant increase in body temperature and loss in the body weigth then all animals die during 4 -5 day.The postmortem changes included hemorrhages , and congestion in all organs particularly in the subcutaneous tissue. Hematological changes including increase in the packed cell volume and hemoglobin concentration ,and erythrocytic count and leukocytosis with neutrophilia and lymphopenia .Significant increase in the aspartate and alanine aminotraferease activities , serum sodium and potassium ions , and inhibition in blood cholinesterase activity in both erythrocytes and plasma in 2 and 24 houres after injection as compared to the values in animals before injection.