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1.
Chemosphere ; 242: 125293, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31896202

RESUMO

The effects produced by the ethyl-carbamates: ethyl-4-bromophenyl carbamate (LQM 919) and ethyl-4-chlorophenyl carbamate (LQM 996) on the mortality and behavior of Apis mellifera were evaluated by the acute oral toxicity test and the acute contact toxicity test. The oral lethal dose, 50% of the ethyl-carbamates was >145.24 µg per bee, and the oral lethal dose, 50% of propoxur was 0.072 µg per bee. Therefore, according to the OECD criteria, the ethyl-carbamates were classified as relatively nontoxic orally; meanwhile, propoxur was classified as highly toxic orally. In the contact test, lethal concentrations 50% of the ethyl-carbamates were 4.83 and 2.23 µg/cm2 for LQM 919 and LQM 996, respectively; therefore, they were at least 10-fold less lethal (p < 0.05) than propoxur (0.22 µg/cm2). The ethyl-carbamates reduced the activity of A. mellifera acetylcholinesterase by up to 30%. The ki and kd values of both ethyl-carbamates were lower (p < 0.05) than those of propoxur and indicated that they are weak inhibitors and with low affinity to A. mellifera acetylcholinesterase, which along with the absence of behavioral alterations suggests that the mortality caused by ethyl carbamates is not related to damage to the nervous system. According to these results, the evaluated ethyl-carbamates can be considered a low ecotoxic risk for A. mellifera.


Assuntos
Acetilcolinesterase/metabolismo , Abelhas/efeitos dos fármacos , Carbamatos/toxicidade , Poluentes Ambientais/toxicidade , Inseticidas/toxicidade , Animais , Abelhas/enzimologia , Comportamento Animal/efeitos dos fármacos , Exposição Dietética/efeitos adversos , Exposição Ambiental/efeitos adversos , Dose Letal Mediana , Testes de Toxicidade Aguda
2.
Toxicol Lett ; 320: 64-72, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31794810

RESUMO

Oxime-based acetylcholinesterase reactivators (briefly oximes) regenerate organophosphate-inactivated acetylcholinesterase and restore its function. Poor blood-brain-barrier passage and fast elimination from blood limit their actual use in treatment of patients exposed to organophosphates. Previous in vitro results implicated further testing of cucurbit[7]uril as a delivery vehicle for bisquaternary oximes. The present paper focuses on cell toxicity, in vivo safety and influence of cucurbit[7]uril on oxime pharmacokinetics and pharmacodynamics. Neither the K027 nor the complex caused any cell toxicity, changes in blood biochemistry or hepato- or nephrotoxicity in tested concentrations. The encapsulation of K027 increased and accelerated the blood-brain-barrier penetration. The peripheral oxime exposure also increased, supporting the suggestion that cucurbit[7]uril protects the circulating oxime from rapid renal clearance. Contrary to the comparable in vitro reactivation power of K027 and the encapsulated K027, we failed to confirm this in vivo. In theory, this might result from the non-specific binding of molecules to the cucurbit[7]uril or the interaction of K027 with cucurbit[7]uril being too strong for acetylcholinesterase reactivation. Precise explanation requires additional in silico, in vitro and also in vivo experiments.


Assuntos
Acetilcolinesterase/sangue , Acetilcolinesterase/metabolismo , Encéfalo/efeitos dos fármacos , Hidrocarbonetos Aromáticos com Pontes/farmacocinética , Reativadores da Colinesterase/farmacocinética , Eritrócitos/efeitos dos fármacos , Imidazóis/farmacocinética , Oximas/farmacocinética , Compostos de Piridínio/farmacocinética , Células A549 , Animais , Encéfalo/enzimologia , Hidrocarbonetos Aromáticos com Pontes/administração & dosagem , Hidrocarbonetos Aromáticos com Pontes/toxicidade , Sobrevivência Celular/efeitos dos fármacos , Reativadores da Colinesterase/administração & dosagem , Reativadores da Colinesterase/toxicidade , Relação Dose-Resposta a Droga , Eritrócitos/enzimologia , Feminino , Proteínas Ligadas por GPI/sangue , Proteínas Ligadas por GPI/metabolismo , Células Hep G2 , Humanos , Imidazóis/administração & dosagem , Imidazóis/toxicidade , Injeções Intramusculares , Masculino , Dose Máxima Tolerável , Camundongos Endogâmicos ICR , Oximas/administração & dosagem , Oximas/toxicidade , Compostos de Piridínio/administração & dosagem , Compostos de Piridínio/toxicidade , Medição de Risco , Distribuição Tecidual
3.
Toxicol Lett ; 321: 21-31, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31830555

RESUMO

Nerve agents inhibit acetylcholinesterase (AChE), leading to a build-up of acetylcholine (ACh) and overstimulation at cholinergic synapses. Current post-exposure nerve agent treatment includes atropine to treat overstimulation at muscarinic synapses, a benzodiazepine anti-convulsant, and an oxime to restore the function of AChE. Aside from the oxime, the components do not act directly to reduce the overstimulation at nicotinic synapses. The false transmitters acetylmonoethylcholine (AMECh) and acetyldiethylcholine (ADECh) are analogs of ACh, synthesised similarly at synapses. AMECh and ADECh are partial agonists, with reduced activity compared to ACh, so it was hypothesised the false transmitters could reduce overstimulation. Synthetic routes to AMECh and ADECh, and their precursors, monoethylcholine (MECh) and diethylcholine (DECh), were devised, allowing them to be produced easily on a laboratory-scale. The mechanism of action of the false transmitters was investigated in vitro. AMECh acted as a partial agonist at human muscarinic (M1 and M3) and muscle-type nicotinic receptors, and ADECh was a partial agonist only at certain muscarinic subtypes. Their precursors acted as antagonists at muscle-type nicotinic, but not muscarinic receptors. Administration of MECh and DECh improved neuromuscular function in the soman-exposed guinea-pig hemi-diaphragm preparation. False transmitters may therefore help reduce nerve agent induced overstimulation at cholinergic synapses.


Assuntos
Acetilcolina/análogos & derivados , Antídotos/farmacologia , Colina/análogos & derivados , Inibidores da Colinesterase/envenenamento , Diafragma/inervação , Agentes Neurotóxicos/envenenamento , Neurotransmissores/farmacologia , Intoxicação por Organofosfatos/tratamento farmacológico , Soman/envenenamento , Sinapses/efeitos dos fármacos , Acetilcolina/síntese química , Acetilcolina/metabolismo , Acetilcolina/farmacologia , Acetilcolinesterase/metabolismo , Animais , Antídotos/síntese química , Células CHO , Linhagem Celular Tumoral , Colina/síntese química , Colina/farmacologia , Cricetulus , Agonismo Parcial de Drogas , Cobaias , Humanos , Masculino , Neurotransmissores/síntese química , Intoxicação por Organofosfatos/enzimologia , Intoxicação por Organofosfatos/fisiopatologia , Receptores Colinérgicos/efeitos dos fármacos , Receptores Colinérgicos/genética , Receptores Colinérgicos/metabolismo , Sinapses/enzimologia
4.
J Enzyme Inhib Med Chem ; 35(1): 330-343, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31856607

RESUMO

Cholinesterase inhibitor plays an important role in the treatment of patients with Alzheimer's disease (AD). Herein, we report the medicinal chemistry efforts leading to a new series of 1,3-dimethylbenzimidazolinone derivatives. Among the synthesised compounds, 15b and 15j showed submicromolar IC50 values (15b, eeAChE IC50 = 0.39 ± 0.11 µM; 15j, eqBChE IC50 = 0.16 ± 0.04 µM) towards acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Kinetic and molecular modelling studies revealed that 15b and 15j act in a competitive manner. 15b and 15j showed neuroprotective effect against H2O2-induced oxidative damage on PC12 cells. This effect was further supported by their antioxidant activity determined in a DPPH assay in vitro. Morris water maze test confirmed the memory amelioration effect of the two compounds in a scopolamine-induced mouse model. Moreover, the hepatotoxicity of 15b and 15j was lower than tacrine. In summary, these data suggest 15b and 15j are promising multifunctional agents against AD.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Antioxidantes/farmacologia , Benzimidazóis/farmacologia , Inibidores da Colinesterase/farmacologia , Desenho de Drogas , Acetilcolinesterase/metabolismo , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/antagonistas & inibidores , Peptídeos beta-Amiloides/metabolismo , Animais , Antioxidantes/síntese química , Antioxidantes/química , Benzimidazóis/síntese química , Benzimidazóis/química , Butirilcolinesterase/metabolismo , Morte Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Inibidores da Colinesterase/síntese química , Inibidores da Colinesterase/química , Relação Dose-Resposta a Droga , Electrophorus , Células Hep G2 , Cavalos , Humanos , Camundongos , Camundongos Endogâmicos ICR , Modelos Moleculares , Estrutura Molecular , Células PC12 , Fragmentos de Peptídeos/antagonistas & inibidores , Fragmentos de Peptídeos/metabolismo , Agregados Proteicos/efeitos dos fármacos , Ratos , Relação Estrutura-Atividade
5.
Food Chem ; 307: 125523, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31639572

RESUMO

Lutein is a bioactive found in dark leafy vegetables that may be used as a nutraceutical agent in foodstuff and an inhibitor of key enzymes of the human body such as those involved in the cholinergic system. However, its high hydrophobicity leads to low bioavailability and must be overcome if lutein is to be added in foods. The objective of this study was to evaluate the influence of nanoencapsulated lutein in the activity of the acetylcholinesterase enzyme. The in vitro study was carried out using water in order to evaluate the impact of encapsulation on the hydrophilicity of lutein. In vitro assays showed that lutein, both free and nanoencapsulated, presented a mixed-type inhibition behavior, and encapsulated lutein was able to inhibit acetylcholinesterase activity even in an aqueous medium. Inhibition was also showed by the in silico docking results which show that lutein interacted with the pocket region of the enzyme.


Assuntos
Acetilcolinesterase/metabolismo , Cápsulas/química , Luteína/química , Simulação de Acoplamento Molecular , Nanopartículas/química , Acetilcolinesterase/química , Sítios de Ligação , Suplementos Nutricionais/análise , Humanos , Interações Hidrofóbicas e Hidrofílicas , Cinética , Luteína/metabolismo , Estrutura Terciária de Proteína
6.
Bioelectrochemistry ; 131: 107392, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31707277

RESUMO

A flexible acetylcholinesterase (AChE) film biosensor, based on a AuNPs-MoS2-reduced graphene oxide/polyimide flexible film (rGO/PI) electrode, has been synthesized for paraoxon detection. In this study, the rGO/PI film acts as the flexible substrate and AuNPs are reduced by monolayer MoS2 under illumination. Transmission electron microscopy revealed that AuNPs are uniformly dispersed on the MoS2-rGO/PI electrode surface with a diameter ~10nm. X-ray photoelectron spectroscopy indicated that a strong binding force exists between reduced AuNPs and monolayer MoS2. The AChE modified AuNPs-MoS2-rGO/PI flexible film biosensor is used to hydrolyze acetylcholine chloride and obtain a large current response at 0.49V by differential pulse voltammetry, demonstrating successful immobilization of AChE. In view of the inhibition of paraoxon on the AChE, under optimal conditions, the AChE/AuNPs-MoS2-rGO/PI film biosensor shows a linear response over a concentration range 0.005-0.150µg/mL, a sensitivity of 4.44 uA/µg/mL, a detection limit of 0.0014µg/mL, acceptable reproducibility and stability to paraoxon. The flexible film biosensor has also proved used for detection of paraoxon in real samples.


Assuntos
Acetilcolinesterase/metabolismo , Técnicas Biossensoriais , Dissulfetos/química , Ouro/química , Grafite/química , Inseticidas/análise , Molibdênio/química , Nanopartículas/química , Paraoxon/análise , Limite de Detecção
7.
J Enzyme Inhib Med Chem ; 35(1): 118-128, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31694418

RESUMO

A series of novel quinolinone derivatives bearing dithiocarbamate moiety were designed and synthesised as multifunctional AChE inhibitors for the treatment of AD. Most of these compounds exhibited strong and clearly selective inhibition to eeAChE. Among them, compound 4c was identified as the most potent inhibitor to both eeAChE and hAChE (IC50 = 0.22 µM for eeAChE; IC50 = 0.16 µM for hAChE), and it was also the best inhibitor to AChE-induced Aß aggregation (29.02% at 100 µM) and an efficient inhibitor to self-induced Aß aggregation (30.67% at 25 µM). Kinetic and molecular modelling studies indicated that compound 4c was a mixed-type inhibitor, which could interact simultaneously with the catalytic anionic site (CAS) and the peripheral anionic site (PAS) of AChE. In addition, 4c had good ability to cross the BBB, showed no toxicity on SH-SY5Y neuroblastoma cells and was well tolerated in mice at doses up to 2500 mg/kg (po).


Assuntos
Acetilcolinesterase/metabolismo , Doença de Alzheimer/tratamento farmacológico , Inibidores da Colinesterase/química , Quinolonas/química , Tiocarbamatos/química , Animais , Barreira Hematoencefálica/metabolismo , Inibidores da Colinesterase/administração & dosagem , Inibidores da Colinesterase/efeitos adversos , Desenho de Drogas , Feminino , Humanos , Masculino , Camundongos , Simulação de Acoplamento Molecular , Ligação Proteica , Quinolonas/administração & dosagem , Quinolonas/efeitos adversos
8.
J Enzyme Inhib Med Chem ; 35(1): 211-226, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31760822

RESUMO

Pursuing the widespread interest on multi-target drugs to combat Alzheimer´s disease (AD), a new series of hybrids was designed and developed based on the repositioning of the well-known acetylcholinesterase (AChE) inhibitor, tacrine (TAC), by its coupling to benzofuran (BF) derivatives. The BF framework aims to endow the conjugate molecules with ability for inhibition of AChE (bimodal way) and of amyloid-beta peptide aggregation, besides providing metal (Fe, Cu) chelating ability and concomitant extra anti-oxidant activity, for the hybrids with hydroxyl substitution. The new TAC-BF conjugates showed very good activity for AChE inhibition (sub-micromolar range) and good capacity for the inhibition of self- and Cu-mediated Aß aggregation, with dependence on the linker size and substituent groups of each main moiety. Neuroprotective effects were also found for the compounds through viability assays of neuroblastoma cells, after Aß1-42 induced toxicity. Structure-activity relationship analysis provides insights on the best structural parameters, to take in consideration for future studies in view of potential applications in AD therapy.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Benzofuranos/farmacologia , Inibidores da Colinesterase/farmacologia , Fármacos Neuroprotetores/farmacologia , Tacrina/farmacologia , Acetilcolinesterase/metabolismo , Doença de Alzheimer/metabolismo , Animais , Benzofuranos/química , Inibidores da Colinesterase/síntese química , Inibidores da Colinesterase/química , Relação Dose-Resposta a Droga , Electrophorus , Humanos , Modelos Moleculares , Estrutura Molecular , Fármacos Neuroprotetores/síntese química , Fármacos Neuroprotetores/química , Relação Estrutura-Atividade , Tacrina/química
9.
Toxicol Lett ; 321: 83-89, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31863869

RESUMO

Acetylcholinesterase (AChE) is a pivotal enzyme in neurotransmission. Its inhibition leads to cholinergic crises and could ultimately result in death. A related enzyme, butyrylcholinesterase (BChE), may act in the CNS as a co-regulator in terminating nerve impulses and is a natural plasma scavenger upon exposure to organophosphate (OP) nerve agents that irreversibly inhibit both enzymes. With the aim of improving reactivation of cholinesterases phosphylated by nerve agents sarin, VX, cyclosarin, and tabun, ten phenyltetrahydroisoquinoline (PIQ) aldoximes were synthesized by Huisgen 1,3 dipolar cycloaddition between alkyne- and azide-building blocks. The PIQ moiety may serve as a peripheral site anchor positioning the aldoxime moiety at the AChE active site. In terms of evaluated dissociation inhibition constants, the aldoximes could be characterized as high-affinity ligands. Nevertheless, high binding affinity of these oximes to AChE or its phosphylated conjugates did not assure rapid and selective AChE reactivation. Rather, potential reactivators of phosphylated BChE, with its enlarged acyl pocket, were identified, especially in case of cyclosarin, where the reactivation rates of the lead reactivator was 100- and 6-times that of 2-PAM and HI-6, respectively. Nevertheless, the return of the enzyme activity was affected by the nerve agent conjugated to catalytic serine, which highlights the lack of the universality of reactivators with respect to both the target enzyme and OP structure.


Assuntos
Butirilcolinesterase/metabolismo , Reativadores da Colinesterase/farmacologia , Agentes Neurotóxicos/toxicidade , Intoxicação por Organofosfatos/tratamento farmacológico , Oximas/farmacologia , Acetilcolinesterase/química , Acetilcolinesterase/metabolismo , Butirilcolinesterase/química , Inibidores da Colinesterase/toxicidade , Reativadores da Colinesterase/síntese química , Ativação Enzimática , Proteínas Ligadas por GPI/agonistas , Proteínas Ligadas por GPI/antagonistas & inibidores , Proteínas Ligadas por GPI/química , Proteínas Ligadas por GPI/metabolismo , Humanos , Cinética , Intoxicação por Organofosfatos/enzimologia , Organofosfatos/toxicidade , Compostos Organofosforados/toxicidade , Compostos Organotiofosforados/toxicidade , Oximas/síntese química , Conformação Proteica , Sarina/toxicidade , Relação Estrutura-Atividade
10.
J Enzyme Inhib Med Chem ; 35(1): 31-41, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31645149

RESUMO

The present study describes the synthesis of a novel series of thiazolidin-4-one and thiazinan-4-one using 1-(2-aminoethyl)pyrrolidine as amine precursor. All compounds were synthesised by one-pot three component cyclocondensation reaction from the amine, a substituted benzaldehyde and a mercaptocarboxylic acid. The compounds were obtained in moderate to good yields and were identified and characterised by 1H, 13 C, 2 D NMR and GC/MS techniques. The compounds also were screened for their in vitro acetylcholinesterase (AChE) activity in hippocampus and cerebral cortex on Wistar rats. The six most potent compounds have been investigated for their cytotoxicity by cell viability assay of astrocyte primary culture, an important cell of central nervous system. We highlighted two compounds (6a and 6k) that had the lowest IC50 in hippocampus (5.20 and 4.46 µM) and cerebral cortex (7.40 and 6.83 µM). These preliminary and important results could be considered a starting point for the development of new AChE inhibitory agents.


Assuntos
Acetilcolinesterase/metabolismo , Inibidores da Colinesterase/farmacologia , Tiazinas/farmacologia , Tiazolidinas/farmacologia , Animais , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/enzimologia , Inibidores da Colinesterase/síntese química , Inibidores da Colinesterase/química , Relação Dose-Resposta a Droga , Hipocampo/efeitos dos fármacos , Hipocampo/enzimologia , Estrutura Molecular , Ratos , Ratos Wistar , Relação Estrutura-Atividade , Tiazinas/síntese química , Tiazinas/química , Tiazolidinas/síntese química , Tiazolidinas/química
11.
Ecotoxicol Environ Saf ; 187: 109673, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31698196

RESUMO

The herbicide glyphosate [N- (phosphonomethyl) glycine; PMG] and the insecticide chlorpyrifos [O, O-diethyl O- (3,5,6-trichloro-2-pyridinyl) -phosphorothioate, CPF] are widely used in agricultural practices around the world and can reach aquatic environments. Therefore, it is necessary to characterize the toxicity of these pesticides on non-target species. The use of biomarkers as a tool to assess responses of organisms exposed to pollutants requires the understanding of their natural fluctuation and the dose-response relationship. In the present work, the effect of the exposure to PMG and CPF on the acetylcholinesterase activity (AChE, biomarker of neurotoxicity) in Cnesterodon decemmaculatus, a native teleost, was evaluated in different environmental conditions. Semi-static bioassays of acute toxicity were carried out under controlled conditions during the four weather seasons of the year using animals of homogeneous size. Circannual rhythms in the basal levels of AChE activity in homogenates of the anterior section were confirmed. Statistically significant average inhibition of AChE activity (47.1 ±â€¯0.7% for 1 µg CPF × L-1; 69.7 ±â€¯2.5% for 5 µg CPF × L-1; 23.1 ±â€¯1.1% for 1 mg PMG × L-1 and 32.9 ±â€¯3.3% for 10 mg PMG × L-1) was determined during summer, winter and spring weather seasons. Interestingly, animals exhibit an increased susceptibility to exposure during the autumn season (inhibition of 55.4 ±â€¯0.6% for 1 µg CPF × L-1; 81.9 ±â€¯3.3% for 5 µg CPF × L-1; 41.4 ±â€¯1.7% for 1 mg PMG × L-1 and 61.1 ±â€¯0.3% for 10 mg PMG × L-1). A different sensitivity of the enzyme between seasons was evaluated by in vitro tests. The inhibition pattern for chlorpyrifos-oxon (CPF-oxon, the active metabolite of CPF) was not affected when test was performed using homogenates of unexposed specimens of summer or autumn. Otherwise, PMG in vitro inhibitory effect was not observed in a wide range of concentrations. The results confirm that AChE activity is a sensitive biomarker for exposure to CPF and PMG, even at environmentally relevant concentrations. Finally, this work highlights the existence of seasonal variations in the dose-response relationship, which could be due to variations in the metabolism of the pollutants.


Assuntos
Acetilcolinesterase/metabolismo , Clorpirifos/análogos & derivados , Inibidores da Colinesterase/toxicidade , Ciprinodontiformes/metabolismo , Glicina/análogos & derivados , Estações do Ano , Poluentes Químicos da Água/toxicidade , Animais , Biomarcadores/metabolismo , Clorpirifos/toxicidade , Relação Dose-Resposta a Droga , Água Doce/química , Glicina/toxicidade
12.
Food Chem ; 309: 125766, 2020 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-31718836

RESUMO

This study aimed to identify by UPLC-PDA-Q/TOF-MS and quantify by UPLC-PDA phenolic compounds (26 flavonols and 2 phenolic acids) and carotenoids (16) from berries of different cultivars of Hippophaë rhamnoides and determine correlations between these variables and in vitro anticholinergic and on-line antioxidant potential. Isorhamnetin derivatives presented over 65% of total flavonols, but quercetin and kaempferol derivatives were also determined. Carotenes accounted for 19 to 47%, xanthophylls 16 to 81% of total carotenoids. Pearson's correlations between AChE and BuChE inhibition and phenolic acid content were low (r = 0.388 and 0.355), moderate for carotenoids (0.504 and 0.437) and high for flavonols (0.851 and 0.614). The PCA biplot showed the highest correlation between anticholinergic activity and all-trans-ß-cryptoxanthin, quercetin-3-O-glucoside, isorhamnetin-3-O-(2-rhamnosyl)glucoside, kaempferol-3-O-hexoside-7-O-rhamnoside, isorhamnetin-3-O-(6-rhamnosyl)hexoside, isorhamnetin-3-O-rutinoside, and isorhamnetin-3-O-glucoside concentrations. The results obtained can be used to identify sea buckthorn cultivars, develop crops and production, and design functional products rich in flavonols and carotenoids with anticholinergic properties.


Assuntos
Antioxidantes/química , Carotenoides/análise , Inibidores da Colinesterase/análise , Cromatografia Líquida de Alta Pressão/métodos , Hippophae/química , Fenóis/análise , Acetilcolinesterase/química , Acetilcolinesterase/metabolismo , Butirilcolinesterase/química , Butirilcolinesterase/metabolismo , Inibidores da Colinesterase/química , Flavonóis/análise , Frutas/química , Frutas/metabolismo , Hippophae/metabolismo , Análise de Componente Principal
13.
J Enzyme Inhib Med Chem ; 34(1): 712-727, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31852270

RESUMO

The design of multi-target directed ligands (MTDLs) is a valid approach for obtaining effective drugs for complex pathologies. MTDLs that combine neuro-repair properties and block the first steps of neurotoxic cascades could be the so long wanted remedies to treat neurodegenerative diseases (NDs). By linking two privileged scaffolds with well-known activities in ND-targets, the flavonoid and the N,N-dibenzyl(N-methyl)amine (DBMA) fragments, new CNS-permeable flavonoid - DBMA hybrids (1-13) were obtained. They were subjected to biological evaluation in a battery of targets involved in Alzheimer's disease (AD) and other NDs, namely human cholinesterases (hAChE/hBuChE), ß-secretase (hBACE-1), monoamine oxidases (hMAO-A/B), lipoxygenase-5 (hLOX-5) and sigma receptors (σ1R/σ2R). After a funnel-type screening, 6,7-dimethoxychromone - DBMA (6) was highlighted due to its neurogenic properties and an interesting MTD-profile in hAChE, hLOX-5, hBACE-1 and σ1R. Molecular dynamic simulations showed the most relevant drug-protein interactions of hybrid 6, which could synergistically contribute to neuronal regeneration and block neurodegeneration.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Inibidores Enzimáticos/farmacologia , Flavonoides/farmacologia , Metilaminas/farmacologia , Regeneração Nervosa/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Acetilcolinesterase/metabolismo , Doença de Alzheimer/metabolismo , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Araquidonato 5-Lipoxigenase/metabolismo , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Ácido Aspártico Endopeptidases/metabolismo , Barreira Hematoencefálica/efeitos dos fármacos , Barreira Hematoencefálica/metabolismo , Butirilcolinesterase/metabolismo , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Flavonoides/química , Humanos , Masculino , Metilaminas/química , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Modelos Moleculares , Estrutura Molecular , Monoaminoxidase/metabolismo , Fármacos Neuroprotetores/síntese química , Fármacos Neuroprotetores/química
15.
Invest Ophthalmol Vis Sci ; 60(14): 4759-4773, 2019 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-31738824

RESUMO

Purpose: Reaggregates from E6 embryonic chicken retina exhibit areas corresponding to an inner plexiform layer (IPL), which presents an ideal in vitro model to test conditions and constraints of cholinergic and glutamatergic network formation, providing a basis for retinal tissue engineering. Here, we show that ipl formation is regulated by cholinergic starburst amacrine cells (SACs), a glial scaffold and by L-glutamate. Methods: Rosetted spheroids were cultured in absence or presence of 0.2 to 0.4 mM L-glutamate and analyzed by immuno- and enzyme histochemistry, proliferation, and apoptosis assays. Results: After 2 days in vitro (div), ipl formation was announced by acetylcholinesterase+ (AChE) and choline acetyltransferase+ (ChAT) cells. Individual vimentin+ or transitin+ Müller glial cell precursors (MCPs) in ipl centers coexpressed ChAT. Comparable to in vivo, pairwise arranged ChAT+ SACs formed two laminar subbands. Projections of calretinin+ amacrine cells (ACs) into ipl associated with MCP processes. In L-glutamate-, or NMDA-treated spheroids ipls were disrupted, including loss of SACs and MCs; coincubation with NMDA receptor inhibitor MK-801 prevented these effects. Also, many Pax6+ cells, comprising most ACs, were lost, while rho4D2+ rod photoreceptors were increased. Cell proliferation was slightly increased, while apoptosis remained unaffected. Conclusions: This demonstrated: (1) a far-advanced differentiation of an IPL in retinal spheroids, as never described before; (2) ipl sublamination was initiated by cholinergic precursor cells, which-functioning as "ipl founder cells"-(3) gave rise to neurons and glial cells; (4) these SACs and MCPs together organized ipl formation; and (5) this process was counteracted by NMDA-dependent glutamate actions.


Assuntos
Diferenciação Celular/fisiologia , Colinérgicos/farmacologia , Células Ependimogliais/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo , Retina/embriologia , Transdução de Sinais/fisiologia , Esferoides Celulares/efeitos dos fármacos , Acetilcolinesterase/metabolismo , Animais , Proliferação de Células/fisiologia , Células Cultivadas , Embrião de Galinha , Colina O-Acetiltransferase/metabolismo , Crioultramicrotomia , Ácido Glutâmico/farmacologia , Imuno-Histoquímica , Marcação In Situ das Extremidades Cortadas , Neurônios Retinianos/citologia , Esferoides Celulares/metabolismo , Fixação de Tecidos , Vimentina/metabolismo
16.
BMC Complement Altern Med ; 19(1): 296, 2019 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-31694704

RESUMO

BACKGROUND: Bergenia ciliata is a medicinal plant used for the treatment of diarrhea, vomiting, fever, cough, diabetes, cancer, pulmonary disorders and wound healing. METHODS: In this study, Bergenia ciliata crude extract, subfractions, and isolated compounds were evaluated for their antioxidant and anticholinesterase potential. The free radical scavenging capacities of the extracts determined using DPPH and ABTS assays. The anticholinesterase potentials were determined using acetylcholine esterase and butyryl choline esterase enzymes. To determine the phytochemical composition, the extracts were subjected to HPLC analysis and silica gel column isolation. Based on HPLC fingerprinting results, the ethyl acetate fraction was found to have more bioactive compounds and was therefore subjected to silica gel column isolation. As a result, three compounds; pyrogallol, rutin, and morin were isolated in the pure state. The structures of the isolated compounds were elucidated using spectroscopic techniques like 1H-NMR, IR and UV-Visible. RESULTS: The crude extract showed maximum anticholinesterase (acetylcholinesterase = 90.22 ± 1.15% and butyrylcholinesterase = 88.22 ± 0.71%) and free radical scavenging (87.37 ± 2.45 and 83.50 ± 0.70% respectively against DPPH and ABTS radicals) potentials. The total phenolic contents (expressed as equivalent of gallic acid; mgGAE/g) were higher in ethyl acetate fraction (80.96 ± 1.74) followed by crude extract (70.65 ± 0.86) while the flavonoid contents (expressed as quercetin equivalent; mgQE/g) and were higher in crude extract (88.40 ± 1.12) followed by n-butanol fraction (60.10 ± 1.86). The isolated bioactive compounds pyrogallol, rutin, and morin were found active against ABTS and DPPH free radicals. Amongst them, pyrogallol was more active against both free radicals. Reasonable anticholinesterase activities were recorded for pyrogallol against selected enzymes. CONCLUSION: The extracts and isolated compounds showed antioxidant and acetylcholinesterase inhibitory potentials. It was concluded that this plant could be helpful in the treatment of oxidative stress and neurological disorders if used in the form of extracts.


Assuntos
Antioxidantes/química , Inibidores da Colinesterase/química , Extratos Vegetais/química , Saxifragaceae/química , Acetilcolinesterase/química , Antioxidantes/isolamento & purificação , Butirilcolinesterase/química , Inibidores da Colinesterase/isolamento & purificação , Flavonoides/química , Flavonoides/isolamento & purificação , Fenóis/química , Fenóis/isolamento & purificação , Extratos Vegetais/isolamento & purificação , Rizoma/química
17.
J Environ Public Health ; 2019: 3084501, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31611921

RESUMO

Biomonitoring of pesticides exposure has currently become a matter of great public concern due to the potential health effects of pesticides. This study assessed levels of acetylcholinesterase (AChE) inhibition and associated health effects in uncontrolled smallholder farming systems in rural Tanzania. A cross-sectional study was conducted of 90 exposed farmers and 61 nonexposed controls from horticultural zones. A structured questionnaire was administered, and a capillary blood sample of 10 µl was used to measure AChE activity using an Erythrocyte Acetylcholinesterase Test Mate Photometric Analyzer kit (Model 400). A multiple logistic regression model was used to investigate determinants of pesticide exposure. The study revealed that smallholder farmers are occupationally exposed to pesticides. Exposed farmers had significantly lower AChE levels. The use of personal protective equipment (PPE) did not significantly reduce the likelihood of AChE inhibition. Women, younger and older farmers, and underweight, overweight, and obese farmers were at increased risk of AChE inhibition. Increase in age (10 years) increased likelihood of AChE inhibition by 6.7%, while decrease in BMI increased likelihood of AChE inhibition by 86.7% while increased pesticides contact hours increased risk of having lower AChE at about 3 times. The number of exposure symptoms (14.10 ± 7.70) was higher in exposed farmers than unexposed. Self-reported symptoms are confirmed to correlate to lower AChE. Prevalence of tiredness (71.6% against 15.5%), fatigue (64.8% against 27.6%), soreness in joints (59.1% against 20.7%), thirst (52.3% against 12.1%), skin irritation (52.1% against 17.2%), salivation and abdominal pain (50% against 8.6% and 31.0%, respectively), muscle weakness (47.7% against 24.1%), and memory loss (47.7% against and 29.3%) differed significantly between exposed and control. This study provides useful information regarding the level of occupational and environmental exposure to pesticides in smallholder horticultural production systems. Pesticides use needs to be controlled at farm level by developing pesticides monitoring and surveillance systems.


Assuntos
Acetilcolinesterase/sangue , Fazendeiros/estatística & dados numéricos , Exposição Ocupacional/estatística & dados numéricos , Praguicidas , Adulto , Doenças dos Trabalhadores Agrícolas/induzido quimicamente , Doenças dos Trabalhadores Agrícolas/enzimologia , Doenças dos Trabalhadores Agrícolas/epidemiologia , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Exposição Ocupacional/efeitos adversos , Equipamento de Proteção Individual/estatística & dados numéricos , Praguicidas/efeitos adversos , Praguicidas/análise , Prevalência , Fatores de Risco , População Rural , Autorrelato , Tanzânia
18.
J Agric Food Chem ; 67(43): 11986-11993, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31593461

RESUMO

Global Natural Product Social feature-based networking was applied to follow the phytochemicals, including nine flavonoid glycosides, six catechins, and three flavonols in Huangjinya green tea. Further, a new 8-O-4'-type neolignan glycoside, camellignanoside A (1), and 15 known compounds (2-16) were isolated through a variety of column chromatographies, and the structure was elucidated extensively by ultra performance liquid chromatography-quadrupole-time-of-flight-tandem mass spectrometry, 1H and 13C nuclear magnetic resonance, heteronuclear single-quantum correlation, heteronuclear multiple-bond correlation, 1H-1H correlation spectroscopy, rotating frame nuclear Overhauser effect spectroscopy, and Nuclear Overhauser effect spectroscopy, and circular dichroism spectroscopies. Compounds 1 and 2 showed acetylcolinesterase inhibition activity, with IC50 = 0.75 and 0.18 µM, respectively.


Assuntos
Camellia sinensis/química , Inibidores da Colinesterase/química , Glicosídeos/química , Lignanas/química , Extratos Vegetais/química , Acetilcolinesterase/química , Cromatografia Líquida de Alta Pressão , Humanos , Cinética , Estrutura Molecular , Folhas de Planta/química , Espectrometria de Massas em Tandem , Chá/química
19.
Chem Biol Interact ; 314: 108845, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31593690

RESUMO

Phenazines, naturally produced by bacteria and archaeal Methanosarcina species are nitrogen-containing tricyclic molecules with antibiotic, antitumoral, and antiparasitic activities. Phenazines are used as electron acceptors-donors in wide range of fields including environmental biosensors. In this study, the inhibitory effects of a synthetic phenazine dye, methylene violet 3RAX (also known as diethyl safranine) on human erythrocyte AChE and human plasma BChE were tested and also its inhibitory mechanisms for both enzymes were studied in detail. Kinetic analyses showed that methylene violet 3RAX acts as a hyperbolic noncompetitive inhibitor of AChE with Ki value of 1.58 ±â€¯0.36 µM; α = 1; ß = 0.12 ±â€¯0.0003. On the other hand, it caused linear competitive inhibition of BChE with Ki value of 0.51 ±â€¯0.006 µM; α = ∞. In conclusion, methylene violet 3RAX which is a highly effective inhibitor of both human AChE and human BChE with Ki values in low micromolar range may be a promising candidate for the treatment of Alzheimer's disease.


Assuntos
Acetilcolinesterase/metabolismo , Butirilcolinesterase/metabolismo , Inibidores da Colinesterase/química , Fenotiazinas/química , Acetilcolinesterase/química , Butirilcolinesterase/química , Inibidores da Colinesterase/metabolismo , Humanos , Cinética , Fenotiazinas/metabolismo
20.
Zhongguo Zhong Yao Za Zhi ; 44(15): 3213-3220, 2019 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-31602874

RESUMO

A total of 27 endophytic fungal strains were isolated from Huperzia serrata,which were richly distributed in the stems and leaves while less distributed in roots. The 27 strains were identified by Internal Transcribed Spacer( ITS) r DNA molecular method and one of the strains belongs to Basidiomycota phylum,and other 26 stains belong to 26 species,9 general,6 families,5 orders,3 classes of Ascomycota Phylum. The dominant strains were Colletotrichum genus,belonging to Glomerellaceae family,Glomerellales order,Sordariomycetes class,Ascomycota Phylum,with the percentage of 48. 15%. The inhibitory activities of the crude extracts of 27 endophytic fungal strains against acetylcholinesterase( ACh E) and nitric oxide( NO) production were evaluated by Ellman's method and Griess method,respectively. Crude extracts of four fungi exhibited inhibitory activities against ACh E with an IC50 value of 42. 5-62. 4 mg·L~(-1),and some fungi's crude extracts were found to inhibit nitric oxide( NO) production in lipopolysaccharide( LPS)-activated RAW264. 7 macrophage cells with an IC50 value of 2. 2-51. 3 mg·L~(-1),which indicated that these fungi had potential anti-inflammatory activities.The chemical composition of the Et OAc extract of endophytic fungus HS21 was also analyzed by LCMS-IT-TOF. Seventeen compounds including six polyketides,four diphenyl ether derivatives and seven meroterpenoids were putatively identified.


Assuntos
Ascomicetos/química , Ascomicetos/classificação , Huperzia/microbiologia , Acetilcolinesterase , Animais , Anti-Inflamatórios/isolamento & purificação , Anti-Inflamatórios/farmacologia , Ascomicetos/isolamento & purificação , Inibidores da Colinesterase/isolamento & purificação , Inibidores da Colinesterase/metabolismo , Endófitos/classificação , Endófitos/isolamento & purificação , Camundongos , Células RAW 264.7
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