Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 3.358
Filtrar
1.
Life Sci ; 250: 117585, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32243928

RESUMO

AIMS: Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) have been associated with risk factors for metabolic syndrome (MetS). Our objective was to evaluate the effect of nicotinamide (NAM) on the activities, expression and protein content of cholinesterases in a MetS model. MAIN METHODS: MetS was induced in male rats administrating 40% fructose to the drinking water for 16 weeks. Additionally, from 5th week onward, the carbohydrate solution was replaced by NAM, at several concentrations for 5 h each morning for the next 12 weeks. In the 15th week, the glucose tolerance test was conducted, and blood pressure was measured. After the treatment period had concluded, the biochemical profile; oxidant stress; proinflammatory markers; and the activity, quantity and expression of cholinesterases were evaluated, and molecular docking analysis was performed. KEY FINDINGS: The MetS group showed anthropometric, hemodynamic and biochemical alterations and increased cholinesterase activity, inflammation and stress markers. In the liver, cholinesterase activity and mRNA, free fatty acid, tumor necrosis factor-alpha (TNF-α), and thiobarbituric acid-reactive substance (TBARS) levels were increased, while reduced glutathione (GSH) levels were decreased. NAM partially or totally decreased risk factors for MetS, markers of stress and inflammation, and the activity (serum and liver) and expression (liver) of cholinesterases. Molecular docking analysis showed that NAM has a greater affinity for cholinesterases than acetylcholine (ACh), suggesting NAM as an inhibitor of cholinesterases. SIGNIFICANCE: Supplementation with 40% fructose induced MetS, which increased the activity and expression of cholinesterases, oxidative stress and the inflammation. NAM attenuated these MetS-induced alterations and changes in cholinesterases.


Assuntos
Inflamação/metabolismo , Síndrome Metabólica/tratamento farmacológico , Niacinamida/uso terapêutico , Estresse Oxidativo , Receptores Colinérgicos/metabolismo , Acetilcolinesterase/metabolismo , Animais , Antropometria , Anti-Inflamatórios/uso terapêutico , Arildialquilfosfatase/metabolismo , Butirilcolinesterase/metabolismo , Colinesterases/metabolismo , Frutose , Regulação da Expressão Gênica , Teste de Tolerância a Glucose , Hemodinâmica , Humanos , Peroxidação de Lipídeos , Fígado/enzimologia , Masculino , Síndrome Metabólica/induzido quimicamente , Simulação de Acoplamento Molecular , Ratos , Ratos Sprague-Dawley
2.
Ecotoxicology ; 29(3): 314-326, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32107698

RESUMO

Anthropogenic activities promote changes in community structure and decrease the species abundance of amphibians. The aim of this study was to assess potential alterations in the antioxidant system and cholinesterase activity, histopathological and oxidative damage in Lithobates catesbeianus tadpoles exposed to water from the Cascavel River, in Southern Brazil. Water samples (140 L each) were collected from the headwater, urban and rural areas of the river. Tadpoles were acclimated for seven days. After acclimatization tadpoles were reared in water from the river, except for the control aquarium. After seven days, a portion of the liver was removed and prepared for cholinesterase (ChE), superoxide dismutase (SOD), catalase (CAT) and lipid peroxidation (LPO) analysis; another part of the tissue was prepared for histological examination. An elevation of CAT activity was observed for water from both urban and rural environments. A decrease in LPO reaction was detected, mainly among the tadpoles exposed to water from the rural area. These alternations can cause delay the metamorphosis and lead to metabolic dysfunction, interfering in survival capacity and diminishing, not only individual fitness, but that of the whole population.


Assuntos
Antioxidantes/metabolismo , Colinesterases/metabolismo , Rana catesbeiana/fisiologia , Poluentes Químicos da Água/toxicidade , Animais , Brasil , Larva/fisiologia , Peroxidação de Lipídeos , Metamorfose Biológica/efeitos dos fármacos , Rios , Poluentes Químicos da Água/metabolismo
3.
Phytochemistry ; 169: 112162, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31627115

RESUMO

Twelve undescribed triterpenoid pentacyclic glycosides, medicagenic acid (3-O-ß-D-glucuronopyranosyl-28-O-{[ß-D-glucopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)]-[α-L-rhamnopyranosyl-(1 → 3)]-4-O-acetyl-ß-D-fucopyranosyl-(1→)}-2ß,3ß-dihydroxyolean-12-ene-23,28-dioic acid, 3-O-ß-D-glucuronopyranosyl-28-O-{[α-L-rhamnopyranosyl-(1 → 2)]-[ß-D-apiofuranosyl-(1 → 3)]-4-O-acetyl-ß-D-fucopyranosyl-(1→)}-2ß,3ß-dihydroxyolean-12-ene-23,28-dioic acid, 3-O-ß-D-glucuronopyranosyl-28-O-{[α-L-rhamnopyranosyl-(1 → 2)]-3,4-O-diacetyl-ß-D-fucopyranosyl-(1→)}-2ß,3ß-dihydroxyolean-12-ene-23,28-dioic acid, 28-O-{[6-O-acetyl-ß-D-glucopyranosyl-(1 → 2)]-[2-O-acetyl-α-L-rhamnopyranosyl-(1 → 4)-ß-D-glucopyranosyl-(1 → 6)]-ß-D-glucopyranosyl-(1→)}-2ß,3ß-dihydroxyolean-12-ene-23,28-dioic acid, 28-O-{[6-O-acetyl-ß-D-glucopyranosyl-(1 → 2)]-[3-O-acetyl-α-L-rhamnopyranosyl-(1 → 4)-ß-D-glucopyranosyl-(1 → 6)]-ß-D-glucopyranosyl-(1→)}-2ß,3ß-dihydroxyolean-12-ene-23,28-dioic acid, 28-O-{[6-O-acetyl-ß-D-glucopyranosyl-(1 → 2)]-[4-O-acetyl-α-L-rhamnopyranosyl-(1 → 4)-ß-D-glucopyranosyl-(1 → 6)]-ß-D-glucopyranosyl-(1→)}-2ß,3ß-dihydroxyolean-12-ene-23,28-dioic acid, 28-O-{[6-O-acetyl-ß-D-glucopyranosyl-(1 → 2)]-[ß-D-glucopyranosyl-(1 → 6)]-ß-D-glucopyranosyl-(1→)}-2ß,3ß-dihydroxyolean-12-ene-23,28-dioic acid, 28-O-{[ß-D-glucopyranosyl-(1 → 2)]-[ß-D-glucopyranosyl-(1 → 6)]-ß-D-glucopyranosyl-(1→)}-2ß,3ß-dihydroxyolean-12-ene-23,28-dioic acid), zanhic acid (3-O-ß-D-glucuronopyranosyl-28-O-{[ß-D-glucopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)]-[α-L-rhamnopyranosyl-(1 → 3)]-4-O-acetyl-ß-D-fucopyranosyl-(1→)}2ß,3ß,16α-trihydroxyolean-12-ene-23,28-dioic acid, 3-O-ß-D-glucuronopyranosyl-28-O-{[ß-D-glucopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)]-ß-D-fucopyranosyl-(1→)}-2ß,3ß,16α-trihydroxyolean-12-ene-23,28-dioic acid), 29-hydroxy-medicagenic acid (3-O-ß-D-glucuronopyranosyl-28-O-{[ß-D-glucopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)]-[α-L-rhamnopyranosyl-(1 → 3)]-4-O-acetyl-ß-D-fucopyranosyl-(1→)}-2ß,3ß,29ß-trihydroxyolean-12-ene-23,28-dioic acid) and herniaric acid (28-O-{[6-O-acetyl-ß-D-glucopyranosyl-(1 → 2)]-[α-L-rhamnopyranosyl-(1 → 4)-ß-D-glucopyranosyl-(1 → 6)]-ß-D-glucopyranosyl-(1→)}-2ß,3ß-dihydroxyolean-18-ene-23,28-dioic acid) were isolated from the whole plant extract of Herniaria glabra L. (Caryophyllaceae), wild growing in the Ukraine. In addition, five known triterpenoid saponins; i.e. herniariasaponins 1, 4, 5, 6, and 7 were also isolated. Their structures were elucidated by HRESIMS, 1D and 2D NMR spectroscopy, as well as by comparison with the literature data. Twelve herniariasaponins, the purified crude extract, and the saponin fraction were evaluated in vitro for their xanthine oxidase, collagenase, elastase, and tyrosinase inhibitory activity. Moreover, herniariasaponins 4, 5, and 7 were screened for their cholinesterase inhibitory potential. As a result, no or low inhibition towards the mentioned enzymes was observed.


Assuntos
Caryophyllaceae/química , Inibidores Enzimáticos/farmacologia , Extratos Vegetais/farmacologia , Saponinas/farmacologia , Animais , Colinesterases/metabolismo , Colagenases/metabolismo , Inibidores Enzimáticos/química , Inibidores Enzimáticos/isolamento & purificação , Conformação Molecular , Monofenol Mono-Oxigenase/antagonistas & inibidores , Monofenol Mono-Oxigenase/metabolismo , Elastase Pancreática/antagonistas & inibidores , Elastase Pancreática/metabolismo , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Saponinas/química , Saponinas/isolamento & purificação , Estereoisomerismo , Ucrânia , Xantina Oxidase/antagonistas & inibidores , Xantina Oxidase/metabolismo
4.
Artigo em Inglês | MEDLINE | ID: mdl-31874287

RESUMO

Pharmaceutical drugs are usually and continuously carried to the aquatic environment in different ways. Thus, they are pseudo-persistent in the environment, and they may exert deleterious effects on aquatic organisms. The objective of the present study was to investigate the acute and chronic effects of two widely used pharmaceutical drugs, paracetamol (analgesic and antipyretic) and propranolol (ß-blocker) on the activity of specific biomarkers (namely cholinesterase enzymes and lactate dehydrogenase) of the neotropical fish Phalloceros harpagos. The obtained results indicate an inhibition of the activity of the enzyme lactate dehydrogenase (LDH) after acute exposure to paracetamol, and an increase in cholinesterase activity in acutely propranolol-exposed fish. Chronic exposure to both drugs did not modify the enzymatic activities. Such short-term changes in enzymatic activities may be harmful to organisms, altering the preferential pathway of energy metabolism, and may induce behavioral changes that may compromise prey capture and predator escape, and in the longer term may induce population declines.


Assuntos
Acetaminofen/toxicidade , Colinesterases/metabolismo , Ciprinodontiformes/metabolismo , L-Lactato Desidrogenase/metabolismo , Propranolol/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Biomarcadores/metabolismo , Poluição Química da Água
5.
PLoS Pathog ; 15(12): e1008213, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31809524

RESUMO

Cholinesterase (ChE) function in schistosomes is essential for orchestration of parasite neurotransmission but has been poorly defined with respect to the molecules responsible. Interrogation of the S. mansoni genome has revealed the presence of three ChE domain-containing genes (Smche)s, which we have shown to encode two functional acetylcholinesterases (AChE)s (Smache1 -smp_154600 and Smache2 -smp_136690) and a butyrylcholinesterase (BChE) (Smbche1 -smp_125350). Antibodies to recombinant forms of each SmChE localized the proteins to the tegument of adults and schistosomula and developmental expression profiling differed among the three molecules, suggestive of functions extending beyond traditional cholinergic signaling. For the first time in schistosomes, we identified ChE enzymatic activity in fluke excretory/secretory (ES) products and, using proteomic approaches, attributed this activity to the presence of SmAChE1 and SmBChE1. Parasite survival in vitro and in vivo was significantly impaired by silencing of each smche, either individually or in combination, attesting to the essential roles of these molecules. Lastly, in the first characterization study of a BChE from helminths, evidence is provided that SmBChE1 may act as a bio-scavenger of AChE inhibitors as the addition of recombinant SmBChE1 to parasite cultures mitigated the effect of the anti-schistosome AChE inhibitor 2,2- dichlorovinyl dimethyl phosphate-dichlorvos (DDVP), whereas smbche1-silenced parasites displayed increased sensitivity to DDVP.


Assuntos
Colinesterases/metabolismo , Schistosoma mansoni/enzimologia , Animais , Camundongos , Transdução de Sinais/fisiologia
6.
Chem Biodivers ; 16(12): e1900434, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31587473

RESUMO

Terpenes are a widespread group of secondary metabolites that can be found in various family plants such as the Lamiaceae. In view of their numerous valuable biological activities, the industrial production of concrete terpenes and essential oils rich in the substances is intensively studied. Monoterpenes constitute a significant part of the whole group of the aforementioned secondary metabolites. This is due to their numerous biological activities and their ability to permeate the skin. Despite the fact that these substances have gain popularity, they are not comprehensively characterized. The presented review is based on studies of the biological activities of the most important monoterpenes and the essential oils rich in these compounds. The authors focused attention on antioxidant activity, inhibition towards acetyl- and butyrylcholinesterase, and α-amylase and α-glucosidase, antifungal, hepatoprotective, sedative properties, and their skin permeation enhancement.


Assuntos
Monoterpenos/química , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/patologia , Animais , Antioxidantes/química , Colinesterases/química , Colinesterases/metabolismo , Lamiaceae/química , Lamiaceae/metabolismo , Monoterpenos/farmacologia , Monoterpenos/uso terapêutico , Fator 2 Relacionado a NF-E2/química , Fator 2 Relacionado a NF-E2/metabolismo , Óleos Voláteis/química , Estresse Oxidativo/efeitos dos fármacos
7.
Biomed Pharmacother ; 118: 109318, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31398669

RESUMO

BACKGROUND: In the context of the cholinergic anti-inflammatory pathway, the clinical trial Anticholium® per Se (EudraCT Number: 2012-001650-26, ClinicalTrials.gov NCT03013322) addressed the possibility of taking adjunctive physostigmine salicylate treatment in septic shock from bench to bedside. Pharmacokinetics (PK) are likely altered in critically ill patients; data on physostigmine PK and target concentrations are sparse, particularly for continuous infusion. Our objective was to build a population PK (popPK) model for physostigmine, and further evaluate pharmacodynamics (PD) and concentration-response relationship in this setting. METHODS: In the randomized, double-blind, placebo-controlled trial, 20 patients with perioperative septic shock either received an initial dose of 0.04 mg/kg physostigmine salicylate, followed by continuous infusion of 1 mg/h for up to 120 h, or equivalent volumes of 0.9% sodium chloride (placebo group). Physostigmine plasma concentrations and acetylcholinesterase (AChE) activity were measured; concentration-response associations were evaluated, and popPK and PD modeling was performed with NONMEM. RESULTS: Steady state physostigmine plasma concentrations reached 7.60 ±â€¯2.81 ng/mL (mean ±â€¯standard deviation [SD]). PK was best described by a two-compartment model with linear clearance. Significant covariate effects were detected for body weight and age on clearance, as well as a high inter-individual variability of the central volume of distribution. AChE activity was significantly reduced to 30.5%-50.6% of baseline activity during physostigmine salicylate infusion. A sigmoidal direct effect PD model best described enzyme inhibition by physostigmine, with an estimated half maximal effective concentration (EC50) of 5.99 ng/mL. CONCLUSIONS: PK of physostigmine in patients with septic shock displayed substantial inter-individual variability with body weight and age influencing the clearance. Physostigmine inhibited AChE activity with a sigmoidal concentration-response effect.


Assuntos
Modelos Biológicos , Fisostigmina/análogos & derivados , Choque Séptico/tratamento farmacológico , Idoso , Colinesterases/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fisostigmina/administração & dosagem , Fisostigmina/farmacocinética , Fisostigmina/uso terapêutico , Choque Séptico/sangue
8.
J Environ Sci Health B ; 54(11): 883-891, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31311415

RESUMO

The characterization of soluble cholinesterases (ChEs) together with carboxylesterases (CEs) in Ficopomatus enigmaticus as suitable biomarkers of neurotoxicity was the main aim of this study. ChEs of F. enigmaticus were characterized considering enzymatic activity, substrate affinity (acetyl-, butyryl-, propionylthiocholine), kinetic parameters (Km and Vmax) and in vitro response to model inhibitors (eserine hemisulfate, iso-OMPA, BW284C51), and carbamates (carbofuran, methomyl, aldicarb, and carbaryl). CEs were characterized based on enzymatic activity, kinetic parameters and in vitro response to carbamates (carbofuran, methomyl, aldicarb, and carbaryl). Results showed that cholinesterases from F. enigmaticus showed a substrate preference for acetylthiocholine followed by propionylthiocholine; butyrylthioline was not hydrolyzed differently from other Annelida species. CE activity was in the same range of cholinesterase activity with acetylthiocholine as substrate; the enzyme activity showed high affinity for the substrate p-nytrophenyl butyrate. Carbamates inhibited ChE activity with propionylthiocholine as substrate to a higher extent than with acetylthiocoline. Also CE activity was inhibited by all tested carbamates except carbaryl. In vitro data highlighted the presence of active forms of ChEs and CEs in F. enigmaticus that could potentially be inhibited by pesticides at environmentally relevant concentration.


Assuntos
Anelídeos/enzimologia , Inibidores da Colinesterase/toxicidade , Colinesterases/química , Neurotoxinas/toxicidade , Animais , Anelídeos/efeitos dos fármacos , Biomarcadores/química , Carbamatos/química , Carbaril/química , Carbaril/toxicidade , Carbofurano/química , Carbofurano/toxicidade , Hidrolases de Éster Carboxílico/antagonistas & inibidores , Hidrolases de Éster Carboxílico/química , Hidrolases de Éster Carboxílico/metabolismo , Inibidores da Colinesterase/química , Colinesterases/metabolismo , Cinética , Metomil/química , Metomil/toxicidade , Neurotoxinas/química
9.
Chemosphere ; 235: 885-899, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31284137

RESUMO

Harmful effects of triclosan (TCS) have been reported on several organisms; however, effects on early life stages of marine vertebrates are limited. Therefore, the objective of this work was to assess the effects of TCS during early development of the flatfish Solea senegalensis after initial characterization of cholinesterases (ChEs) and determination of selected biochemical markers baseline levels. Characterization of ChEs and determination of biochemical markers baseline levels of cholinergic activity, energy metabolism and oxidative stress were analysed in sole at 3 days after hatching (dah) and at the onset and end of metamorphosis. To assess TCS effects, fish were exposed during 96h to 30-500 µg L-1 TCS until 3 dah. Fish at 13 dah were exposed during 48h to 200-1,500 µg L-1 TCS and maintained until complete metamorphosis. Effects on survival, malformations, length, metamorphosis progression and biochemical markers were evaluated. The main ChE active form present in sole early life stages is acetylcholinesterase and baseline levels of oxidative stress and energy metabolism biomarkers changed according to fish developmental stage. Triclosan induced malformations (EC50 = 180 µg L-1 at 3 dah), decreased growth (95 µg L-1 at 3 dah; 548 µg L-1 at 24 dah) and affected metamorphosis progression (391 µg L-1 at 17 dah). Impairment of antioxidant system was observed, with TCS affecting catalase at the end of metamorphosis test, however, no oxidative damage on lipids was detected. Glutathione S-transferase was the most sensitive endpoint during early larval test (LOEC = 30 µg L-1). Exposure to TCS affected S. senegalensis at individual and sub-individual levels, both at early larval stage and during the critical period of metamorphosis.


Assuntos
Linguados/embriologia , Larva/efeitos dos fármacos , Metamorfose Biológica/efeitos dos fármacos , Triclosan/toxicidade , Acetilcolinesterase/metabolismo , Animais , Catalase/metabolismo , Colinesterases/metabolismo , Metabolismo Energético/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Triclosan/metabolismo
10.
Fish Physiol Biochem ; 45(4): 1355-1366, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31177354

RESUMO

Cholinesterases are multifunctional enzymes and have been associated with diverse physiological functions in addition to their classical role at synapses. In the present study, cholinesterase (ChE) isozymes have been characterised in mucous secretions and their activity has been localised in the epidermis of Labeo rohita and Cirrhinus mrigala. Zymography using specific substrates and inhibitors revealed the presence of two ChE isozymes-ChE-1 and ChE-2. The isozyme ChE-1 was characterised as an atypical butyrylcholinesterase and ChE-2 as a typical acetylcholinesterase in skin mucous secretions of both the fish species. Enzyme histochemical analysis demonstrated the presence of ChE activity in the epidermis of the fish species investigated. In both the fish species, strong ChE activity was observed in the outer-layer epithelial cells, taste buds and neuromasts. The middle and basal layer epithelial cells showed moderate to weak ChE activity. Club cells and mucous goblet cells showed the absence of ChE activity. Characterisation with specific inhibitors indicates that acetylcholinesterase (AChE) was the major cholinesterase type expressed in the epidermis of the two fish species investigated. Immunohistochemical localisation of apoptotic and cell proliferation markers, in addition, revealed high expression of active caspase 3 in the outer-layer epithelial cells, and proliferating cell nuclear antigen (PCNA) in the middle and basal layer epithelial cells. High ChE activity in caspase 3-positive cells in the outer layer of the epidermis and low in PCNA-positive cells in middle and basal layers could point towards the possible involvement of ChEs in cell death and their final extrusion from skin surface.


Assuntos
Colinesterases/metabolismo , Cyprinidae/metabolismo , Epiderme/enzimologia , Proteínas de Peixes/metabolismo , Muco/metabolismo , Animais , Cyprinidae/anatomia & histologia , Epiderme/anatomia & histologia , Isoenzimas/metabolismo
11.
Mol Biol Rep ; 46(4): 4517-4527, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31209743

RESUMO

The present study aimed to compare the effect of carvacrol essential oil and carvacrol nanoemulsion against experimental Alzheimer's (AD). Forty male albino rats were used and divided into four groups as follow: control, AlCl3 induced AD, carvacrol oil treated and carvacrol nanoemulsion treated groups. Brain nor-epinephrine, serotonin and dopamine were analyzed by high performance liquid chromatography (HPLC). Levels of brain Thiobarbituric acid-reactive substances (TBARS), Superoxide dismutase (SOD), reduced glutathione (GSH), cholinesterase, and advanced oxidation protein product (AOPP) were evaluated. Urinary 8-hydroxyguanosine (8-OHdG) level was evaluated by HPLC. Brain Cyclooxygenase 1 and 2 (COX 1and 2) were analyzed by immunohistochemistry. AD induced by AlCl3 in rats was depicted by the significant increase in the neurotransmitters levels which is accompanied with high degree of oxidative stress that was revealed in the elevated level of urinary 8-OHdG along with significant elevation in AOPP, TBARS, and cholinesterase levels and a significant decrease in SOD and GSH; these results are confirmed by immunohistochemistry analysis of COX 1 and 2. On the other hand, the treatment with carvacrol oil and carvacrol nanoemulsion were capable of mitigate effects mediated by AlCl3 administration in treated rats. While the treatment with both approached succeeded to retract the negative impact of AlCl3; but the effect of carvacrol nanoemulsion was more notable than the essential oil. Carvacrol oil and carvacrol nanoemulsion were eminent to overturn AlCl3 induced brain AD which could be imputed to antioxidant and anti-inflammatory capabilities of carvacrol to alter oxidative stress effect. In extension; carvacrol nanoemulsion were evident to give more effective and efficient way in carvacrol delivery to pass through blood brain barriers and ameliorate brain changes.


Assuntos
Doença de Alzheimer/metabolismo , Nanopartículas/uso terapêutico , /análise , Produtos da Oxidação Avançada de Proteínas/metabolismo , Animais , Antioxidantes/metabolismo , Encéfalo/metabolismo , Colinesterases/metabolismo , Modelos Animais de Doenças , Glutationa/metabolismo , Masculino , Nanopartículas/química , Fármacos Neuroprotetores/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Prostaglandina-Endoperóxido Sintases/metabolismo , Ratos , Ratos Wistar , Superóxido Dismutase/metabolismo , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo
12.
Chem Biol Interact ; 309: 108714, 2019 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-31228470

RESUMO

Acetylcholinesterase (AChE) is an enzyme which terminates the cholinergic neurotransmission, by hydrolyzing acetylcholine at the nerve and nerve-muscle junctions. The reversible inhibition of AChE was suggested as the pre-treatment option of the intoxications caused by nerve agents. Based on our derived 3D-QSAR model for the reversible AChE inhibitors, we designed and synthesized three novel compounds 8-10, joining the tacrine and aroylacrylic acid phenylamide moieties, with a longer methylene chain to target two distinct, toplogically separated anionic areas on the AChE. The targeted compounds exerted low nanomolar to subnanomolar potency toward the E. eel and human AChE's as well as the human BChE and showed mixed inhibition type in kinetic studies. All compounds were able to slow down the irreversible inhibition of the human AChE by several nerve agents including tabun, soman and VX, with the estimated protective indices around 5, indicating a valuable level of protection. Putative noncovalent interactions of the selected ligand 10 with AChE active site gorge were finally explored by molecular dynamics simulation suggesting a formation of the salt bridge between the protonated linker amino group and the negatively charged Asp74 carboxylate side chain as a significant player for the successful molecular recognition in line with the design strategy. The designed compounds may represent a new class of promising leads for the development of more effective pre-treatment options.


Assuntos
Substâncias para a Guerra Química/química , Inibidores da Colinesterase/química , Colinesterases/metabolismo , Substâncias Protetoras/química , Acetilcolinesterase/química , Acetilcolinesterase/metabolismo , Sítios de Ligação , Domínio Catalítico , Substâncias para a Guerra Química/metabolismo , Inibidores da Colinesterase/metabolismo , Colinesterases/química , Humanos , Cinética , Simulação de Dinâmica Molecular , Compostos Organofosforados/química , Compostos Organofosforados/metabolismo , Substâncias Protetoras/metabolismo , Relação Quantitativa Estrutura-Atividade , Soman/química , Soman/metabolismo
13.
Chem Biol Interact ; 310: 108702, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31247192

RESUMO

Competing substrate kinetic analysis of human butyrylcholinesterase (BChE) and acetylcholinesterase (AChE) from the time-course of enzyme-catalyzed substrate hydrolysis, using spectrophotometric assays is described. This study is based on the use of a chromogenic reporter "visible" substrate (substrate A), whose complete hydrolysis time course is retarded by a competing "invisible" substrate (substrate B). For BChE, four visible substrates were used, two thiocholine esters, benzoylthiocholine and butyrylthiocholine, and two aryl-acylamides, o-nitro trifluoro acetaminide and 3-(acetamido)-N,N,N-trimethylanilinium. Three different competing invisible substrates were used, phenyl acetate, acetylcholine and butyrylcholine. For AChE, two visible substrates were used, acetylthiocholine and 3-(acetamido)-N,N,N-trimethylanilinium. For AChE, acetylcholine was competing with visible substrates. The ratio (R) of bimolecular rate constants, kcat/Km, for all couples of substrates, invisible/visible (B/A) covered all possible limit situations, R ≪ 1, R ≈ 1 and R ≫ 1. The kinetic approach, based on the method developed by Golicnik and Masson allowed determination of binding and catalytic parameters of cholinesterases for both visible and invisible substrates. This analysis was applied to michaelian and non-michaelian catalytic behaviors (activation and inhibition by excess substrate). Reevaluation of catalytic parameters obtained for acetylcholine and butyrylcholine more than 50 years ago was made. The method is fast, reliable, and particularly suitable for poorly soluble substrates and for substrates B when no direct spectrophotometric assays exist. Moreover, replacing substrate B by a reversible inhibitor, mechanism of cholinesterase inhibition was possible to study. It is therefore, useful for screening libraries of new substrates and inhibitors, and/or screening of new cholinesterase mutants. This method can be applied to any other enzymes.


Assuntos
Biocatálise , Colinesterases/metabolismo , Especificidade por Substrato , Acetilcolinesterase/metabolismo , Butirilcolinesterase/metabolismo , Inibidores da Colinesterase , Humanos , Hidrólise , Cinética , Análise Espectral/métodos , Fatores de Tempo
14.
Molecules ; 24(9)2019 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-31064071

RESUMO

As a longstanding problem, Alzheimer's disease (AD) has stymied researchers in the medical field with its increasing incidence and enormous treatment difficulty. Silymarin has always been valued by researchers for its good efficacy and safety in treating liver disease. Recent studies have shown that silymarin also has good pharmacological activity in the nervous system, especially for the treatment of AD. Silymarin can control the production of Aß by inhibiting the precursor substance of Aß (ß-amyloid precursor protein), and it can inhibit the polymerization of Aß. Silymarin can also increase the acetylcholine content in the nervous system by inhibiting cholinesterase activity. At the same time, it also has the effect of resisting oxidative stress and the inflammatory response of the nervous system. These pharmacological activities contribute to the inhibition of the onset of AD. The good efficacy of silymarin on AD and its high safety and availability give it huge potential for the treatment of AD.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Precursor de Proteína beta-Amiloide/antagonistas & inibidores , Silimarina/uso terapêutico , Acetilcolina/metabolismo , Animais , Anti-Inflamatórios/farmacologia , Inibidores da Colinesterase/farmacologia , Colinesterases/metabolismo , Humanos , Estrutura Molecular , Sistema Nervoso/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Silimarina/farmacologia
15.
Artigo em Inglês | MEDLINE | ID: mdl-31129174

RESUMO

The importance of trace elements in ecotoxicological investigations is a well-known issue when monitoring polluted areas such as commercial harbors. Copper represents one of the most common metal contaminants, often detected in these areas as it is widely employed in various fields and has many sources of inflow in the marine environment. Pachygrapsus marmoratus is a widespread intertidal crab species that has been extensively studied in ecology, ethology and population genetics. Ecotoxicological studies have also been performed, exclusively on the adult stage. In the present study we investigated the mortality and biochemical (oxidative stress and neurotoxicity) responses of P. marmoratus larvae exposure to environmental relevant concentration of copper. Results showed dose-dependent responses in terms of larval mortality, with a calculated LC50 value of 0.5 mg/L of Cu2+. The LC50 concentration was used as the starting point for subsequent biochemical response evaluation. Results also demonstrated dose-dependent activation of antioxidant systems assuming a compensatory antioxidant activity to prevent higher cellular damage when larvae were exposed to the highest concentrations of copper. Moreover, a significant enhancement of neurotransmitter activities was observed, assuming a possible direct interaction of copper with the enzymes or an increase of free copper ion aliquot into the cells.


Assuntos
Braquiúros/efeitos dos fármacos , Cobre/toxicidade , Animais , Biomarcadores/metabolismo , Braquiúros/metabolismo , Catalase/metabolismo , Colinesterases/metabolismo , Cobre/administração & dosagem , Relação Dose-Resposta a Droga , Feminino , Glutationa Peroxidase/metabolismo , Larva/efeitos dos fármacos , Mortalidade , Estresse Oxidativo/efeitos dos fármacos , Superóxido Dismutase/metabolismo , Testes de Toxicidade , Poluentes Químicos da Água/administração & dosagem , Poluentes Químicos da Água/toxicidade
16.
PLoS One ; 14(4): e0216077, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31039204

RESUMO

Cholinesterases (ChE), the enzymes whose primary function is the hydrolysis of choline esters, are widely expressed throughout the nature. Although they have already been found in plants and microorganisms, including ascomycete fungi, this study is the first report of ChE-like activity in fungi of the phylum Basidiomycota. This activity was detected in almost a quarter of the 45 tested aqueous fungal extracts. The ability of these extracts to hydrolyse acetylthiocholine was about ten times stronger than the hydrolytic activity towards butyrylthiocholine and propionylthiocholine. In-gel detection of ChE-like activity with acetylthiocholine indicated a great variability in the characteristics of these enzymes which are not characterized as vertebrate-like based on (i) differences in inhibition by excess substrate, (ii) susceptibility to different vertebrate acetylcholinesterase and butyrylcholinesterase inhibitors, and (iii) a lack of orthologs using phylogenetic analysis. Limited inhibition by single inhibitors and multiple activity bands using in-gel detection indicate the presence of several ChE-like enzymes in these aqueous extracts. We also observed inhibitory activity of the same aqueous mushroom extracts against insect acetylcholinesterase in 10 of the 45 samples tested; activity was independent of the presence of ChE-like activity in extracts. Both ChE-like activities with different substrates and the ability of extracts to inhibit insect acetylcholinesterase were not restricted to any fungal family but were rather present across all included Basidiomycota families. This study can serve as a platform for further research regarding ChE activity in mushrooms.


Assuntos
Basidiomycota/enzimologia , Colinesterases/metabolismo , Animais , Basidiomycota/genética , Inibidores da Colinesterase/farmacologia , Colinesterases/genética , Drosophila melanogaster/enzimologia , Genes Fúngicos , Lipase/metabolismo , Filogenia , Especificidade por Substrato/efeitos dos fármacos
17.
Chem Biol Interact ; 308: 224-234, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31100279

RESUMO

Alzheimer's disease (AD) is a multifactorial neurodegenerative process whose effective treatment will require drugs that can act simultaneously on multiple pathogenic targets. Here, we present an overview of our previous multitarget studies of five groups of novel hybrid structures that combine, through spacers, five pharmacophores that have been found promising for AD treatment: γ-carbolines, carbazoles, tetrahydrocarbazoles, phenothiazines, and aminoadamantanes. Biological activity of the compounds was assessed by a battery of assays. These included inhibitory potency against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) as indicators of potential for cognition enhancement and against carboxylesterase (CaE) to exclude unwanted inhibition of this biotransformation pathway. Displacement of propidium from the peripheral anionic site of AChE was determined as a predictor of anti-aggregation activity. Binding to the two sites of the NMDA subtype of the glutamate receptor was conducted as an additional indicator of potential cognition enhancement and neuroprotection. Propensity to protect against mitochondrial triggers of cell death was evaluated by tests of mitochondrial potential and calcium-induced swelling as indicators of mitochondrial permeability transition. Antioxidant potential was measured to evaluate the tendency to prevent oxidative stress. Potential for disease modification was gauged by the ability to stimulate microtubule assembly. Finally, binding modes of conjugates to AChE and BChE were studied using quantum mechanical-assisted molecular docking. We found selective BChE inhibitors (conjugates of γ-carbolines and phenothiazine I, γ-carbolines and carbazoles II, and aminoadamantanes and carbazoles III) as well as inhibitors of both cholinesterases (conjugates of γ-carbolines and methylene blue IV and bis-γ-carbolines with ditriazole-containing spacers V). These compounds combined potentials for cognition enhancement, neuroprotection, and disease modification. None of the conjugates exhibited high potency against CaE, thereby precluding potential drug-drug interactions from CaE inhibition. Thus, the studied compounds exhibited positive characteristics of multitarget drugs, indicating their potential for the next generation of AD therapeutics.


Assuntos
Adamantano/química , Carbazóis/química , Carbolinas/química , Inibidores da Colinesterase/química , Fenotiazinas/química , Adamantano/metabolismo , Adamantano/uso terapêutico , Doença de Alzheimer/tratamento farmacológico , Sítios de Ligação , Carbazóis/metabolismo , Carbazóis/uso terapêutico , Carbolinas/metabolismo , Carbolinas/uso terapêutico , Inibidores da Colinesterase/metabolismo , Inibidores da Colinesterase/uso terapêutico , Colinesterases/química , Colinesterases/metabolismo , Humanos , Simulação de Acoplamento Molecular , Fenotiazinas/metabolismo , Fenotiazinas/uso terapêutico
18.
Chem Biol Interact ; 308: 179-184, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31100280

RESUMO

Within the alpha/beta hydrolase fold superfamily of proteins, the COesterase group (carboxylesterase type B, block C, cholinesterases …) diverged from the other groups through simultaneous integration of an N-terminal, first disulfide bond and a significant increase in the protein mean size. This first disulfide bond ties a large Cys loop, which in the cholinesterases is named the omega loop and forms the upper part of the active center gorge, essential for the high catalytic activity of these enzymes. In some non-catalytic members of the family, the loop may be necessary for heterologous partner recognition. Reshuffling of this protein portion occurred at the time of emergence of the fungi/metazoan lineage. Homologous proteins with this first disulfide bond are absent in plants but they are found in a limited number of bacterial genomes. In prokaryotes, the genes coding for such homologous proteins may have been acquired by horizontal transfer. However, the cysteines of the first disulfide bond are often lost in bacteria. Natural expression in bacteria of CO-esterases comprising this disulfide bond may have required compensatory mutations or expression of new chaperones. This disulfide bond may also challenge expression of the eukaryote-specific cholinesterases in prokaryotic cells. Yet recently, catalytically active human cholinesterase variants with enhanced thermostability were successfully expressed in E. coli. The key was the use of a peptidic sequence optimized through the Protein Repair One Stop Shop process, an automated structure- and sequence-based algorithm for expression of properly folded, soluble and stable eukaryotic proteins. Surprisingly however, crystal structures of the optimized cholinesterase variants expressed in bacteria revealed co-existing formed and unformed states of the first disulfide bond. Whether the bond never formed, or whether it properly formed then broke during the production/analysis process, cannot be inferred from the structural data. Yet, these features suggest that the recently acquired first disulfide bond is difficult to maintain in E. coli-expressed cholinesterases. To explore the fate of the first disulfide bond throughout the cholinesterase relatives, we reanalyzed the crystal structures of representative COesterases members from natural prokaryotic or eukaryotic sources or produced as recombinant proteins in E. coli. We found that in most cases this bond is absent.


Assuntos
Proteínas de Bactérias/química , Carboxilesterase/química , Colinesterases/metabolismo , Dissulfetos/química , Proteínas de Bactérias/metabolismo , Carboxilesterase/metabolismo , Colinesterases/química , Colinesterases/genética , Bases de Dados de Proteínas , Escherichia coli/metabolismo , Evolução Molecular , Humanos
19.
Anim Genet ; 50(3): 287-292, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30994195

RESUMO

Plasma cholinesterase (PCHE) activity is an important auxiliary test in human clinical medicine. It can distinguish liver diseases from non-liver diseases and help detect organophosphorus poisoning. Animal experiments have confirmed that PCHE activity is associated with obesity and hypertension and changes with physiological changes in an animal's body. The objective of this study was to locate the genetic loci responsible for PCHE activity variation in ducks. PCHE activity of Pekin duck × mallard F2 ducks at 3 and 8 weeks of age were analyzed, and genome-wide association studies were conducted. A region of about 1.5 Mb (21.8-23.3 Mb) on duck chromosome 9 was found to be associated with PCHE activity at both 3 and 8 weeks of age. The top SNP, g.22643979C>T in the butyrylcholinesterase (BCHE) gene, was most highly associated with PCHE activity at 3 weeks (-logP = 21.45) and 8 weeks (-logP = 27.60) of age. For the top SNP, the strong associations of CC and CT genotypes with low PCHE activity and the TT genotype with high PCHE activity indicates the dominant inheritance of low PCHE activity. Problems with block inheritance or linkage exist in this region. This study supports that BCHE is a functional gene for determining PCHE levels in ducks and that the genetic variations around this gene can cause phenotypic variations of PCHE activity.


Assuntos
Colinesterases/genética , Patos/genética , Animais , Proteínas Aviárias/sangue , Proteínas Aviárias/genética , Proteínas Aviárias/metabolismo , Butirilcolinesterase/genética , Colinesterases/sangue , Colinesterases/metabolismo , Cruzamentos Genéticos , Patos/sangue , Patos/metabolismo , Feminino , Estudos de Associação Genética , Masculino , Polimorfismo de Nucleotídeo Único
20.
Microb Pathog ; 132: 137-140, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31028864

RESUMO

The role of cholinesterase in inflammatory reactions has been described in several infectious diseases. However, in Brucella spp. this has not yet been studied. Therefore, the objective of this study was to evaluate whether experimental infection by Brucella ovis alters the cholinergic activity in pro- or anti-inflammatory responses to the disease. For the study 48 mice were used, 24 infected by B. ovis and 24 non-infected. We collected samples of whole blood on days 7, 15, 30 and 60 post-infection (PI) by B. ovis. Acetylcholinesterase (AChE) activity in the blood increased on days 15 and 60 PI (P < 0.05). Butyrylcholinesterase (BChE) activity in serum increased on days 7 and 60 PI (P < 0.05). An increase in serum free radical levels occurred on days 7, 15 and 60 PI (P < 0.05), and consequently superoxide dismutase activity increased on day 15 PI (P < 0.05). A reduction in catalase activity occurred when the infection became chronic (60 PI). The increase in AChE and BChE characterized a pro-inflammatory response, since these enzymes regulate levels of acetylcholine (ACh) and butyrylcholine (BuSCh), molecules with anti-inflammatory properties. Therefore, with the increase of cholinesterase activity, there was an extracellular reduction of ACh, an inhibitor of several inflammatory mediators. This proinflammatory response of B. ovis infection leads to oxidative stress, and consequently to cellular damage.


Assuntos
Acetilcolinesterase/metabolismo , Brucella ovis/patogenicidade , Butirilcolinesterase/metabolismo , Colinesterases/metabolismo , Acetilcolina/metabolismo , Acetilcolinesterase/sangue , Animais , Brucelose/sangue , Butirilcolinesterase/sangue , Catalase , Colina/análogos & derivados , Colina/metabolismo , Colinérgicos/farmacologia , Colinesterases/sangue , DNA Bacteriano/análise , Modelos Animais de Doenças , Inflamação , Masculino , Camundongos , Estresse Oxidativo , Espécies Reativas de Oxigênio/sangue , Espécies Reativas de Oxigênio/metabolismo , Soro/enzimologia , Superóxido Dismutase
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA