Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.1.1.7 (acetylcholinesterase)
28,390 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The organophosphorus (OP) pesticide malathion is a highly neurotoxic compound. Although some studies have reported neurotoxicity signs after the in utero exposure to OP pesticides, there is no evidence of the exclusive contribution of the lactational exposure to malathion as a possible cause of neurotoxicity in the offspring. In this study, we investigated the exclusive contribution of malathion exposure through maternal milk on the activity of acetylcholinesterase (AChE), as well as on biochemical parameters related to the oxidative stress (glutathione levels, lipid peroxidation and glutathione reductase and glutathione peroxidase activities) in the brain of suckling mice. The same parameters were also evaluated in the brains of the respective mothers, which where directly exposed to malathion during the lactational period (daily s.c. injections; doses of 20, 60 and 200mg/kg of body weight). Our results showed that the lactational exposure to malathion caused a high inhibitory effect of the brain AChE activity in the offspring, even when dams were exposed to the lowest malathion dose (20mg/kg). Brain AChE activity was also inhibited in mothers; however, only at the highest malathion dose (200mg/kg). No changes were observed in the biochemical parameters related to the oxidative stress for both dams and pups brains. The present study shows, for the first time, that the exposure of neonatal mice to malathion via lactation inhibits the activity of brain AChE in the offspring. These data, summed to the fact that OP pesticides are excreted in human milk, makes relevant the lactational exposure to these xenobiotics in terms of human health concerns.
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PMID:Lactational exposure to malathion inhibits brain acetylcholinesterase in mice. 1671 98

Erythrocytes are excellent models for the study of interactions of xenobiotics with biomembranes. Present work is designed to study the in vitro effects of some organophosphates (ethion, chlorpyrifos, dimethoate and monocrotophos) on rat erythrocytes. Treatment of erythrocytes with organophosphates resulted in decreased erythrocyte glucose-6-phosphate dehydrogenase (G-6-PD) activity, whereas activities of glutathione-s-transferase (GST) and glutathione reductase (GR) were increased. Reduced Glutathione (GSH) content of RBCs was decreased after treatment with the pesticides. Increased activities of GST and GR were due to induction of natural defense mechanism of erythrocytes against the toxicity of the pesticides. Membrane bound enzymes like acetylcholinesterase (AChE), Na(+)-K(+)-ATPase and Ca(2+)-ATPase were also inhibited. Altered activities of these enzymes along with decreased GSH content indicate increased oxidative stress in erythrocytes after treatment with organophosphates.
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PMID:Erythrocyte antioxidant enzymes in toxicological evaluation of commonly used organophosphate pesticides. 1687 49

The current study was carried out to investigate the potential role of 4,5 dihydroxy benzene 1,3 disulfonic acid di sodium salt (Tiron) and glutathione (GSH) either individually or in combination against aluminum (Al)-induced toxicity in Wistar rats. Animals were exposed to aluminum chloride at a dose of 172.5mg/kg/d orally for 10 weeks. Tiron and GSH were administered at a dose of 471-mg/kg/d i.p. and 100mg/kg/d orally, respectively, for 7 consecutive days. Tiron is a diphenolic chelating compound which forms water soluble complexes with a large number of metal ions. Induction of oxidative stress was recorded in brain and serum after Al exposure. Significant decrease was recorded in reduced glutathione (GSH), glutathione reductase (GR), glutathione peroxidase (GP(x)), catalase (CAT), superoxide dismutase (SOD), acetyl cholinesterase (AChE) and an increase was observed in thiobarbituric acid reacting substance (TBARS) and glutathione-S-transferase (GST) in brain and serum. Most of the above parameters responded positively to individual therapy with Tiron, but more pronounced beneficial effects on the above-described parameters were observed when Tiron was administered in combination with GSH. Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) studies also showed significantly high concentration of Al in brain and blood. Tiron was slightly more effective then GSH in reducing the concentration of Al from the brain and blood, however, no further improvement was recorded when Tiron was administered in combination with GSH in reducing the concentration of Al.
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PMID:Role of combined administration of Tiron and glutathione against aluminum-induced oxidative stress in rat brain. 1731 27

Determination of erythrocyte number and their indices and enzymatic activity of: glucose-6-phosphate dehydrogenase (G-6PD), superoxide dismutase (SOD), acetylcholinesterase (AchE), glutathione reductase (GR) and hexokinase (Hx) in peripheral blood erythrocytes of workers chronically exposed to mercury vapours during the production of chloride (the mercuric electrolysis method). The studied workers were equipment operators, electricians and electrolysis maintenance men at the chloride production department using the mercuric electrolysis method. The study involved 46 men, aged 21 to 56, (x = 39 +/- 10.4) exposed to mercury vapours for the period from 7 months to 32 years (x = 14.7+/-10.8), working in a three shift system, for 8 hours a day. Smokers constituted 50% of the studied group (23 men). Urine mercury concentrations of workers exposed to mercury vapours were in the range from 10 to 215 microg/dm3 (x = 81,4 +/- 72,9) and in blood in range 4 do 72 microg/dm3 (x=16.3 +/- 15,0). Controls were 46 men aged 20-54, (x=33.6 +/- 9.8), workers and voluntary blood donors, who never experienced occupational exposure to mercury vapours or other chemicals, and to physical agents. The percentage of smokers in the control group was 34.7% (16 men). Basic haematological determinations (hematocrit - Hct, Hb concentration, erythrocyte number in mm3 of blood, mean red cell hemoglobin concentration (MCHC), mean red cell volume (MCV) and enzymatic studies (activity of G-6PD, SOD, AchE, GR, Hx) in peripheral blood samples obtained from workers and controls were performed. Hematological parameters of the peripheral blood were determined using AVL 808 hematological counter, following the manufacturer's instructions. Activity of the studied enzymes was estimated by the spectrophotometric method described by Beutler, following the recommendations of the International Committee for Standardisation in Hematology. Values of Ht were higher in all the subgroups exposed to Hg workers (divided according to duration of exposure or urine mercury concentrations) in comparison to the control group. The erythrocyte number in mm3 of peripheral blood was also higher in the exposed workers group than in controls. MCHC in the total group exposed to mercury vapours was lower than in the controls. In the subgroup exposed to mercury vapours for < 10 years, the value of this parameter was lower than in the control group; whereas in the subgroups separated in respect to mercury concentration in the urine, it was lower only in workers showing the highest urine concentration of this metal. In workers exposed to mercury vapours, MCV index values were lower than in the controls. In the subgroups of workers who smoked and those who did not smoke, they were also lower than in the controls; whereas in the group of the longest exposed workers from 21 to 35 years, it was found to be higher than in controls. The activity of G6PD was lower in the group of subjects occupationally exposed to mercury vapours than in the control group - 5.60 +/- 1.60 and 7.41 +/- 0.43 IU/gHb respectively. When comparing the subgroups of smokers and non-smokers with the controls, workers showed lower G6PD activity than in the matching control subgroups - 6.24 +/- 1.97 and 7.44 +/-0.22 IU/gHb in the subgroups of smokers and 4.97 +/- 0.72 and 7.38 +/- 0.18 IU/gHb in non-smokers respectively. Erythrocyte G6PD activity was lower in all studied groups separated in respect to exposure time - 5.54 +/- 1.75, 6.02 +/- 2.05 and 5.54 +/- 1.05 IU/gHb respectively. The same pattern of changes was observed in the subgroups separated in respect to mercury concentration in the urine compared to the controls. The lowest enzyme activity was found in the subgroups showing the highest mercury concentration in the urine wnen compared with the subgroup with the lowest urine concentration of this metal - 5.19 +/- 1.50 and 6.00 +/- 1.84 IU/gHb respectively SOD activity in the group of workers exposed to mercury was lower compared to the controls - 2289.97 +/- 122.31 and 2418.03 +/- 60.28 IU/gHb respectively. The smoking and non-smoking workers showed respective SOD activities on - 2305.43 +/- 102.75 and 2274.50 +/- 124.5 IU/gHb; whereas in the matching subgroup of controls - 2452.11 +/- 88.72 and 2382.09 +/- 91.22 IU/gHb, respectively. The activity of this enzyme in all investigated groups selected in respect to length of employment, revealed lower values when compared with the controls - 2271.20 +/- 115.23 in the group with under 10 years of exposure, 2335.11 +/-167.71 IU/gHb in those exposed for 11-20 years, and 2290.40 +/- 26.12 IU/gHb in the subgroup exposed for the longest period of time. Similar changes were observed in the activity of this enzyme in the subgroups separated in respect to mercury concentration in the urine when SOD activity was compared with the controls. The AchE activity was higher in the group exposed to mercury vapours compared to the controls and the respective values were - 50.22 +/- 14.44 and 36.87 +/- 2.92 IU/gHb. In the subgroups separated in respect to length of exposure, the activity of this enzyme was statistically significantly higher than in the control group. The GR activity levels were lower in the exposed group - 8.01 +/-2.54 IU/gHb, compared to the controls - 10.24 +/- 1.24 IU/gHb. In the subgroups of smokers and non-smokers, GR activity was lower, 8.48 +/- 2.37 and 7.54 +/- 2.68 IU/gHb, compared to smokers and non-smokers in the control group, 10.26 +/- 1.01 and 10.16 +/- 1.03 IU/gHb, respectively. The GR activity was also statistically significantly lower in all groups separated in respect to duration of exposure, with the values of 8.56 +/-2.39, 8.26 +/- 2.38, 7.06 +/- 2.75 IU/gHb, respectively in subject groups and 10.24 +/- 1.35 in the control group. Similar changes were noticed in the subgroup separated in respect to mercury concentration in the urine. The Hx activity was lower in the group exposed to mercury vapours - 1.08 +/-0.11. compared with the controls - 1.21 +/- 0.16 IU/gHb. The enzyme activity showed a similar pattern in the subgroups separated in respect to duration of exposure when they were compared with the control group. Exposure to mercury vapours present changes in the red blood cells, manifested by increased (when compared with the control group), number of erythrocytes in peripheral and decreased mean cell volume and mean cell hemoglobin concentration values, as well as changes in the metabolic processes occurring in the erythrocytes. In subjects exposed to mercury vapours some metabolic processes may be additionally modified by addiction to cigarette smoking.
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PMID:[Red cell system and selected red cell enzymes in men occupationally exposed to mercury vapours]. 1778 49

An ecotoxicological protocol with caged mussels, Mytilus galloprovincialis, was developed to evaluate the potential impact of an offshore gas platform in the central Adriatic Sea. Reference organisms were collected on a seasonal basis from an unpolluted site and transplanted for four weeks in both the sampling area and to the investigated platform. Chemical analyses of trace metals in mussel tissues were integrated with a multi-biomarker approach for the early detection of biological responses at several cellular targets. Induction of metallothioneins, peroxisomal proliferation and activity of acetylcholinesterase were measured as markers for specific classes of chemicals. Special attention was given to oxyradical metabolism and appearance of oxidative-mediated toxicity to reveal a more general onset of cellular disturbance. In addition to individual antioxidants (superoxide dismutase, catalase, glutathione S-transferases, glutathione reductase, Se-dependent and Se-independent glutathione peroxidases, and levels of total glutathione), the total oxyradical scavenging capacity (TOSC) allowed a quantification of the overall capability to neutralize specific forms of intracellular reactive oxygen species (ROS; i.e. peroxyl and hydroxyl radicals). Cellular damages were evaluated as lysosomal destabilization (membrane stability, accumulation of lipofuscin and neutral lipids), lipid peroxidation products (malondialdehyde) and DNA integrity (strand breaks and micronuclei); the air survival test was finally applied to evaluate the overall physiological condition of mussels. Concentration of trace metals (As, Ba, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Zn) revealed only limited variations in transplanted mussels during various experimental periods and such changes appeared partly related to natural fluctuations. Among biological responses, variations of antioxidants and lysosomal stability were confirmed as sensitive early warning signals for biological disturbance of both natural and anthropogenic origin. The presented protocol with caged mussels allowed marked biological effects caused by the investigated platform to be excluded, and represented a useful approach that is easy to extend for monitoring the impact of offshore activities in the Adriatic sea.
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PMID:An ecotoxicological protocol with caged mussels, Mytilus galloprovincialis, for monitoring the impact of an offshore platform in the Adriatic Sea. 1789 9

The potency of newly developed asymmetric bispyridinium oximes (K027, K048) in reactivating acetylcholinesterase and in eliminating oxidative stress induced by acute exposure to malathion was evaluated in mouse prefrontal cortex using in vivo methods. Malathion (1g/kg, dissolved in saline) was administered subcutaneously. The asymmetric bispyridinium oximes K027 or K048 (1/4 of LD(50), dissolved in saline, i.p.) were administered immediately after malathion and atropine sulfate (20mg/kg, dissolved in saline, i.p.). Control group received saline instead of malathion and antidotes. Acetylcholinesterase activity and biochemical parameters related to oxidative stress (glutathione levels, glutathione peroxidase and glutathione reductase activity and lipid peroxidation) were evaluated in mouse prefrontal cortex at two different time points (3 or 24 h after malathion poisoning). Malathion administration markedly inhibited cortical acetylcholinesterase activity (around 55%) at 3h after malathion challenge and such inhibition was maintained till 24 h after poisoning. Although neither atropine sulfate nor oximes were able to eliminate cortical acetylcholinesterase inhibition at 3h after malathion poisoning, K027 (in combination with atropine) completely eliminated the inhibitory effect of malathion exposure on cortical acetylcholinesterase activity at 24 h after malathion administration. K048 (in combination with atropine) significantly decreased acetylcholinesterase inhibition at 24 h after malathion poisoning. Even though glutathione levels and glutathione peroxidase and glutathione reductase activities were not affected, malathion administration markedly increased lipid peroxidation in the prefrontal cortex at 24 h after poisoning and the oxime K027 (in combination with atropine) was able to significantly decrease such phenomenon. Thus, our results clearly demonstrate that the newly developed asymmetric bispyridinium oximes K027 and K048 are able to reverse malathion-induced acetylcholinesterase inhibition in mouse prefrontal cortex. Moreover, the ameliorative effect of the oxime K027 on the increased lipid peroxidation observed at 24 h after malathion poisoning suggests a potential link between the hyperstimulation of cholinergic system and oxidative stress in the mouse prefrontal cortex after malathion exposure.
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PMID:Temporal effects of newly developed oximes (K027, K048) on malathion-induced acetylcholinesterase inhibition and lipid peroxidation in mouse prefrontal cortex. 1803 20

The wide use of the organophosphate insecticide malathion is accompanied by the risk of human exposure, especially in developing countries, which underlines the need of basic studies in this area. Some reports have shown that low doses of malathion, in a repeated treatment regimen, are unable to reduce acetylcholinesterase (AChE) activity in the rat brain, in contrast to the inhibitory effect in acute treatment. In order to investigate if AChE activity is affected by repeated low-level malathion administration, female Wistar rats were exposed to malathion (50 and 100 mg/kg, intraperitoneally) for 3 consecutive days. Exposure to malathion 50 mg/kg did not affect AChE activity, as previously observed. Contrary to expectation, 100 mg/kg malathion produced a significant increase in AChE activity in both cerebral cortex and hippocampus. Besides AChE inhibition, malathion may act as a pro-oxidative agent by interfering with antioxidant defences, as shown by a decrease of glutathione peroxidase and glutathione reductase activity in the cerebral cortex (100 mg/kg malathion). These effects are in contrast to response in the hippocampus where the increase in AChE activity correlates positively with the antioxidant defences, while the opposite was found in the cerebral cortex. These data indicate that, with low doses, and after a short period of exposure, malathion induces an up-regulation of AChE activity, a pattern similar to that found in the hippocampus for the antioxidant defences studied. The cerebral cortex was more vulnerable to malathion, as reflected in a decrease of two antioxidant enzymes. This study indicates that (i) alternatively to AChE inhibition, interference with the antioxidant defence system may be another important target for malathion toxicity; (ii) hippocampal and cortical AChE activity in rats can be increased after repeated low-dose malathion exposure. This response suggests the occurrence of a pathophysiological response in order to maintain the homeostasis of the cholinergic system in these cerebral structures.
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PMID:Antioxidant and acetylcholinesterase response to repeated malathion exposure in rat cerebral cortex and hippocampus. 1834 13

The objective of this study was to investigate the effects of two different PAHs and a complex petrochemical mixture on the common goby, Pomatoschistus microps, using selected biomarkers as effect criteria. Benzo[a]pyrene (BaP) and anthracene were used as reference substances, while the water accommodated fraction of #4 fuel-oil (#4 WAF) was used as an example of a petrochemical mixture. P. microps was used since it is both a suitable bioindicator and a good test organism. Groups of fish were exposed to different concentrations of each of the test substances for 96 h and the activities of several enzymes commonly used as biomarkers were determined at the end of the bioassays. All the substances inhibited P. microps acetylcholinesterase (AChE) indicating that they have at least one mechanism of neurotoxicity in common: the disruption of cholinergic transmission by inhibition of AChE. An induction of lactate dehydrogenase (LDH) activity was found in fish exposed to BaP or to anthracene, suggesting an increase of the anaerobic pathway of energy production. On the contrary, inhibition of LDH was found in fish exposed to #4 WAF, suggesting a distinct effect of the mixture. An induction of P. microps glutathione S-transferase (GST) activity was found in fish exposed to BaP or to #4 WAF, while an inhibition was observed after exposure to anthracene. These results suggest that GST is involved in the detoxification of BaP and #4 WAF, but not of anthracene. All the substances increased catalase activity and isolated PAHs also increased superoxide dismutase, glutathione reductase and glutathione peroxidase activities, while #4 WAF did not cause significant alterations on these enzymes. These results suggest that all the substances may induce oxidative stress on P. microps, with BaP and anthracene apparently having more oxidative stress potential than #4 WAF.
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PMID:Acute effects of Benzo[a]pyrene, anthracene and a fuel oil on biomarkers of the common goby Pomatoschistus microps (Teleostei, Gobiidae). 1834 79

The cognitive-enhancing activities of E-harpagoside and 8-O-E-p-methoxycinnamoylharpagide (MCA-Hg) isolated from Scrophularia buergeriana were evaluated in scopolamine-induced amnesic mice by the Morris water maze and by passive avoidance tests. E-harpagoside and MCA-Hg significantly improved the impairment of reference memory induced by scopolamine in the Morris water maze test. The mean escape latency, the mean path length and swimming movement were also improved by both compounds. In passive avoidance test, E-harpagoside and MCA-Hg (2 mg/kg body weight, p.o.) significantly ameliorated scopolamine-induced amnesia by as much as 70% of the level found in normal control mice. Donepezil, an acetylcholinesterase inhibitor and the most widely used drug for AD treatment was employed as a positive control. The activity of acetylcholinesterase was inhibited significantly by E-harpagoside or MCA-Hg within the cortex and hippocampus to a level similar to that observed in mice treated with donepezil (2 mg/kg body weight, p.o.). Moreover, treatment with E-harpagoside or MCA-Hg to scopolamine-induced amnesic mice significantly decreased TBARS level which was accompanied by an increase in the activities or contents of glutathione reductase, SOD and reduced GSH. We believe these data demonstrate that E-harpagoside or MCA-Hg exerted potent cognitive-enhancing activity through both anti-acetylcholinesterase and antioxidant mechanisms.
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PMID:Cognitive-enhancing and antioxidant activities of iridoid glycosides from Scrophularia buergeriana in scopolamine-treated mice. 1846 17

The current therapeutic advance in which future drugs are designed to possess varied pharmacological properties and act on multiple targets has stimulated the development of the multimodal drug, ladostigil (TV3326; (N-propargyl-(3R) aminoindan-5yl)-ethyl methyl carbamate). Ladostigil combines neuroprotective effects with monoamine oxidase (MAO)-A and MAO-B and cholinesterase (ChE) inhibitory activities in a single molecule, as a potential treatment for Alzheimer's disease (AD) and Lewy body disease. In the present study, we demonstrate that ladostigil (10(-6)-10 muM) dose-dependently increased cell viability, associated with increased activity of catalase and glutathione reductase and decrease of intracellular reactive oxygen species production in a cytotoxic model of human SH-SY5Y neuroblastoma cells exposed to hydrogen peroxide (H(2)O(2)). In addition, ladostigil significantly upregulated mRNA levels of several antioxidant enzymes (catalase, NAD(P)H quinone oxidoreductase 1 and peroxiredoxin 1) in both H(2)O(2)-treated SH-SY5Y cells, as well as in the high-density human SK-N-SH neuroblastoma cultured apoptotic models. In vivo chronic treatment with ladostigil (1 mg/kg per os per day for 30 days) markedly upregulated mRNA expression levels of various enzymes involved in metabolism and oxidation processes in aged rat hippocampus. In addition to its unique combination of ChE and MAO enzyme inhibition, these results indicate that ladostigil displays neuroprotective activity against oxidative stress-induced cell apoptosis, which might be valuable for aging and age-associated neurodegenerative diseases.
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PMID:The novel cholinesterase-monoamine oxidase inhibitor and antioxidant, ladostigil, confers neuroprotection in neuroblastoma cells and aged rats. 1875 29


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