ABSTRACT
To develop tools to investigate the biological functions of butyrylcholinesterase (BChE) and the mechanisms by which BChE affects Alzheimer's disease (AD), we synthesized several selective, nanomolar active, pseudoirreversible photoswitchable BChE inhibitors. The compounds were able to specifically influence different kinetic parameters of the inhibition process by light. For one compound, a 10-fold difference in the IC50-values (44.6 nM cis, 424 nM trans) in vitro was translated to an "all or nothing" response with complete recovery in a murine cognition-deficit AD model at dosages as low as 0.3 mg/kg.
Subject(s)
Alzheimer Disease/drug therapy , Butyrylcholinesterase/metabolism , Cholinesterase Inhibitors/therapeutic use , Cognition/drug effects , Neuroprotective Agents/therapeutic use , Nootropic Agents/therapeutic use , Alzheimer Disease/chemically induced , Amyloid beta-Peptides , Animals , Azo Compounds/chemical synthesis , Azo Compounds/metabolism , Azo Compounds/radiation effects , Azo Compounds/therapeutic use , Carbamates/chemical synthesis , Carbamates/metabolism , Carbamates/radiation effects , Carbamates/therapeutic use , Cholinesterase Inhibitors/chemical synthesis , Cholinesterase Inhibitors/metabolism , Cholinesterase Inhibitors/radiation effects , Kinetics , Mice , Molecular Docking Simulation , Neuroprotective Agents/chemical synthesis , Neuroprotective Agents/metabolism , Neuroprotective Agents/radiation effects , Nootropic Agents/chemical synthesis , Nootropic Agents/metabolism , Nootropic Agents/radiation effects , Peptide Fragments , Protein Binding , StereoisomerismABSTRACT
A controlled cross-sectional study of family growers of fruit and vegetables was conducted between October 2009 and October 2010 to characterize the use of pesticides, establish the socio-demographic profile, and analyze cholinesterase activity in small-scale agricultural workers in Southern Brazil. Data was collected for 173 workers and 179 controls. A structured questionnaire was applied collecting socio-demographic information and determining knowledge and work practices in relation to pesticide use. The benchmarks for total cholinesterase (ChEs) and butyrylcholinesterase (BuChE) were obtained from the average enzymatic activity of the occupationally unexposed group (control). The mean age of the exposed population was 40.0 ± 11.2 years. The symptoms differed significantly (p<0.05) between the exposed and unexposed populations. Forty (23.1%) workers showed symptoms associated with exposure to pesticides. The average value of enzymatic activity in the occupationally unexposed group for ChEs was 6.3 μmol/mL/min among males and 5.6 μmol/mL/min among females while for BuChE was 2.4 μmol/mL/min among males and 2.0 μmol/mL/min among females. Eight (4.6%) workers had high inhibition (>30%) of ChEs activity, whereas no workers showed high inhibition (>50%) of BuChE. Potential factors involved include gender, education, pesticide orientation, exposure, and hygiene measures.
Realizou-se um estudo transversal controlado, com hortifruticultores, durante o período de outubro de 2009 a outubro de 2010, a fim de caracterizar o uso de praguicidas, estabelecer o perfil sócio demográfico e analisar a atividade das colinesterases em trabalhadores rurais do sul do Brasil. Os dados foram obtidos de 173 trabalhadores e 179 controles. Um formulário estruturado foi aplicado obtendo informações sócio demográficas, conhecimento e práticas de trabalho relacionadas com o uso de praguicidas. Os valores de referência para colinesterases totais (ChEs) e butirilcolinesterase (BuChE) foram obtidos a partir da média da atividade enzimática do grupo controle. A idade média da população exposta foi de 40,0±11,2 anos. Os sinais/sintomas foram significativamente diferentes (p<0,05) entre a população exposta e não exposta. Quarenta trabalhadores (23,1%) apresentaram sinais/sintomas relacionados com a exposição aos praguicidas. O valor médio do grupo controle foi de 6,3 μmol/mL/min para o gênero masculino e 5,6 μmol/mL/min para o gênero feminino na ChEs; 2,4 μmol/mL/min para o gênero masculino e 2,0 μmol/mL/min para o gênero feminino na BuChE. Do total de trabalhadores (n=173), 08 (4,6%) apresentaram inibição elevada (>30%) das atividades das ChEs, e para BuChE nenhum trabalhador apresentou alta inibição (>50%). Dentre os fatores que poderiam estar envolvidos destacam-se o gênero, escolaridade, orientação para trabalhar com praguicidas, exposição e medidas de higiene.
Subject(s)
Humans , Rural Workers , Cholinesterase Inhibitors/radiation effects , Agrochemicals , Cross-Sectional Studies , Occupational Exposure/classificationABSTRACT
Galantamine hydrobromide was subjected to different stress conditions (acidic, alkaline, thermal, photolytic and oxidative). Degradation was found to occur under acidic, photolytic and oxidative conditions, while the drug was stable under alkaline and elevated temperature conditions. A stability-indicating reversed-phase liquid chromatographic method was developed for the determination of the drug in the presence of its degradation products. The method was validated for linearity, precision, accuracy, specificity, selectivity and intermediate precision. Additionally, the degradation kinetics of the drug was assessed in relevant cases. The kinetics followed a first order behavior in the case of acidic and photolytic degradation, while a two-phase kinetics behavior was found for the oxidative degradation. The degradation products were characterized by mass spectrometry and nuclear magnetic resonance spectroscopy. Dehydration, epimerization and N-oxidation were the main processes observed during the degradation of galantamine. Moreover, if sufficient material could be isolated the inhibitory activity against the target enzyme acetylcholinesterase was also assessed.
