The gastrointestinal nematodes (GIN) stand out as an important cause of disease in small ruminant, especially on goat farm. Widespread resistance to synthetic anthelminthics has stimulated the research for alternative strategies of parasite control, including the use of medicinal plants. The present work summarizes the in vitro and in vivo studies of plants with activity against GIN of goats, focusing on the description of chemical constituents related to this effect. This review retrieved 56 scientific articles from 2008 to 2018 describing more than 100 different plant species. The most frequently investigated family was Fabaceae (30.7%). Most in vitro studies on the activity of plant extracts and fractions were carried out with of free-living stages nematodes. In vivo studies were conducted mainly with the use of plants in animal feed and generally showed lower effectiveness compared to in vitro assays. The main plant secondary metabolites associated with anthelmintic effect are condensed tannins, saponin and flavonoids. However, the studies with compounds isolated from plants and elucidation of their mechanisms of action are scarce. Herbal medicines are thought to be promising sources for the development of effective anthelmintic agents.
The enhancement of cholinergic functions via acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibition is considered a valuable therapeutic strategy for the treatment of Alzheimer’s disease. This study aimed to evaluate the in vitro effect of ZINC390718, previously filtered using computational approaches, on both cholinesterases and to characterize, using a molecular dynamics (MD) simulation, the possible binding mode of this compound inside the cholinesterase enzymes. The in vitro cytotoxicity effect was also investigated using a primary astrocyte-enriched glial cell culture. ZINC390718 presented in vitro dual inhibitory activity against AChE at a high micromolar range (IC50 = 543.8 µM) and against BuChE (IC50 = 241.1 µM) in a concentration-dependent manner, with greater activity against BuChE. The MD simulation revealed that ZINC390718 performed important hydrophobic and H-bond interactions with the catalytic residue sites on both targets. The residues that promoted the hydrophobic interactions and H-bonding in the AChE target were Leu67, Trp86, Phe123, Tyr124, Ser293, Phe295, and Tyr341, and on the BuChE target, they were Asp70, Tyr332, Tyr128, Ile442, Trp82, and Glu197. The cytotoxic effect of Z390718, evaluated via cell viability, showed that the molecule has low in vitro toxicity. The in vitro and in silico results indicate that ZINC390718 can be used as chemotype for the optimization and identification of new dual cholinesterase inhibitors.
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 (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
1 July 2015 in Revista Brasileira de Farmacognosia
The species Marcetia taxifolia (A.St.-Hil.) DC., Melastomataceae, which is endemic of the rupestrian fields of northeastern Brazil, contains a significant amount of flavonoids. In this work, the potential of the ethanolic extract of M. taxifolia as the active principle in a sunscreen photoprotection (UV-A and UV-B) formulation was investigated. The Liquid Chromatography High Performance-Diode Array Detector quantification (quercetin), total flavonoid content, antioxidant activity through 2.2-diphenyl-1- picrylhydrazil method, photoprotective activity against UV-B and UV-A radiation in vitro (spectrophotometric method) and potential for eye irritation using the methodology of the hen egg test-chorioallantoic membrane were performed in the extract. After that, the formulations were prepared using different concentrations of active ethanolic extract (5, 10, 20 and 30%) and the evaluation of the sun protection factor was carried out using the same methodology used for the crude extract. The crude extract showed UV-A photoprotection and low eye irritation in the hen egg test-chorioallantoic membrane test. All formulations containing M. taxifolia extract had ≥ 6 sun protection factor. Its shows the possibility to use this extracts as a sunscreen in pharmaceutical preparations