RESUMO
Inhibition of cholinesterases is a common strategy for the treatment of several disorders, especially Alzheimer´s disease. In vitro assays represent a critical step towards identifying molecules with potential anticholinesterase effect. This study aimed at providing a comprehensive review of the methodologies used in vitro for the anticholinesterase activity based on the spectrophotometry of Ellman's method. This work used two databases (PubMed and ScienceDirect) to search for original articles and selected publications between 1961 and 2019, which reported in vitro spectrophotometry assays for anticholinesterase activity. After the search process and the selection of publications, the final sample consisted of 146 articles published in several journals submitted by researchers from different countries. Although the studies analyzed in this work are all within the same conception of in vitro tests based on Ellman's method, one can observe a wide divergence in the origin and concentration of enzyme, the choice and pH of the buffer, the concentration of the substrate, the sample diluent, incubation time, temperature, and time of the spectrophotometric reading interval. There is no consensus in the methodology of studies with in vitro tests for anticholinesterase assessment. The methodological variations related to kinetic parameters may interfere in the characterization of cholinesterase inhibitors.
Assuntos
Doença de Alzheimer , Inibidores da Colinesterase , Acetilcolinesterase/metabolismo , Inibidores da Colinesterase/química , Inibidores da Colinesterase/farmacologia , Colinesterases/metabolismo , Humanos , Cinética , EspectrofotometriaRESUMO
The dual inhibition of human acetylcholinesterase (hAChE) and butyrylcholinesterase (hBuChE) plays an important role in Alzheimer's disease treatment. Thus, this study aims identify promising dual inhibitors against hAChE and hBuChE by in silico approaches (pharmacophore-based virtual screening and molecular docking). Ten 3 D pharmacophore models for dual inhibitors using default genetic parameters were built by GALAHAD™ available on SYBYL-X 2.0. Validation steps were carried out according to Energy (<100.0 kcal/mol), Pareto = 0, Area under the ROC Curve (>0.70), Boltzmann-Enhanced Discrimination of ROC curve (BEDROC >0.50) and structure-activity relationship (SAR) for known inhibitors. The best dual pharmacophore model based on internal/external statistical parameters and SAR data (one hydrogen bond acceptor, two hydrogen bond donors and four hydrophobic centers) was employed in virtual screening at Sigma-Aldrich® subset (n = 214,446) of ZINC database by UNITY module of SYBYL-X 2.0. According to superposition values (QFIT), the best ranked compounds were prioritized for molecular docking and partition coefficient analysis (clog p < 5.0). 37 top-ranked compounds (QFIT > 64.22) from pharmacophore model showed affinity in hAChE (-10.2 < Affinity energy < -6.3 kcal/mol) and hBuChE (-10.9 < Affinity energy < -2.3 kcal/mol) binding sites. Next, liposolubity prediction and commercially available showed that ZINC43198636, ZINC43198637 and ZINC00390718 can be potential dual inhibitors against hAChE and hBuChE.Communicated by Ramaswamy H. Sarma.