In the effort to obtain multitarget compound interfering with inflammation, oxidative stress, and tumorigenesis, we synthesized a small library of pyrazole compounds, selecting 4a, 4f, and 4g as the most noteworthy being IC50 against platelet ROS production induced by thrombin of about 10 µM. The in vitro antioxidant potential of the three molecules was evaluated, and since they show a remarkable antioxidative activity, their effect on several parameter indicative of oxidative status and on the efficiency of the aerobic metabolism was tested. The three molecules strongly inhibit superoxide anion production, lipid peroxidation, NADPH oxidase activity and almost restore the oxidative phosphorylation efficiency in thrombin-stimulated platelet, demonstrating a protective effect against oxidative stress. This effect was confirmed in endothelial cell in which 4a, 4f, and 4g show an interesting inhibition activity on H2O2-stimulated EA.hy926 cells. At last, antiproliferative activity of 4a, 4f, and 4g was submitted to a large screening at the NCI. The molecules show interesting anticancer activity, among them the most remarkable is 4g able to strongly inhibit the proliferation of both solid tumor and leukemia cells lines. In conclusion, all the three newly synthetized pyrazoles show remarkable antioxidant and antiproliferative effect worthy of further study.
Molecules containing the pyrazole nucleus are widely reported as promising candidates to develop new antimicrobial compounds against multidrug-resistant (MDR) bacteria, where available antibiotics may fail. Recently, aiming at improving the too-high minimum inhibitory concentrations (MICs) of a pyrazole hydrochloride salt (CB1H), CB1H-loaded nanoparticles (CB1H-P7 NPs) were developed using a potent cationic bactericidal macromolecule (P7) as polymer matrix. Here, CB1H-P7 NPs have been successfully tested on several clinical isolates of Gram-positive and Gram-negative species, including relevant MDR strains. CB1H-P7 NPs displayed very low MICs (0.6-4.8 µM), often two-fold lower than those of P7, on 34 out of 36 isolates tested. Upon complexation, the antibacterial effects of pristine CB1H were improved by 2-16.4-fold, and, unexpectedly, also the already potent antibacterial effects of P7 were 2-8 times improved against most of bacteria tested when complexed with CB1H. Time-killing experiments performed on selected species established that CB1H-P7 NPs were bactericidal against
Aiming at developing a dermal formulation against melanoma, the synthesized imidazo-pyrazoles 2-phenyl-2,3-dihydro-1H-imidazo[1,2-b]pyrazole-7-carboxylic acid (3-methoxy-4-phenoxy-benzylidene)-hydrazide (4G) and 2-phenyl-2,3-dihydro-1H-imidazo[1,2-b]pyrazole-7-carboxylic acid (4-benzyloxy-3-methoxy-benzylidene)-hydrazide (4I) were screened on patient-isolated melanoma cells (MEOV NT) and on Vemurafenib (PLX4032)-resistant (MEOV PLX-R) ones. Since 4I on MEOV PLX-R cells was 1.4-fold more effective than PLX, a hydrogel formulation containing 4I (R4HG-4I) was prepared in parallel with an empty R4-based hydrogel (R4HG) using a synthesized antibacterial resin (R4) as gelling agent. Thanks to its high hydrophilicity, porosity (85%), and excellent swelling capability (552%), R4 allowed to achieve R4HG and R4HG-4I with high equilibrium degree of swelling (EDS) and equilibrium water content (EWC). Chemometric-assisted ATR-FTIR analyses confirmed the chemical structure of swollen and fully dried (R4HG-D and R4HG-4I-D) hydrogels. The morphology of R4HG-D and R4HG-4I-D was examined by optical microscopy and SEM, while UV–vis analyses were carried out to obtain the drug loading (DL%) and the encapsulation efficiency (EE%) of R4HG-4I. Potentiometric titrations were performed to determine the equivalents of NH3+ in both R4HG and R4HG-4I. The swelling and water release profiles of both materials and related kinetics were assessed by equilibrium swelling rate and water loss studies, respectively, while their biodegradability over time was assessed by in vitro degradation experiments determining their mass loss. Rheological experiments established that both R4HG and R4HG-4I are shear-thinning Bingham pseudoplastic fluids with low yield stress, thus assuring easy spreadability in a future topical application. Release studies evidenced a sustained and quantitative release of 4I governed mainly by diffusion. Upon favorable results from further experiments in a more realistic 3D model of melanoma, R4HG-4I could represent a starting point to develop new topical therapeutic options to adjuvate the treatments of melanoma cells also when resistant to currently available drugs.
Event Abstract Back to Event Phosphodiesterase 4D inhibition boosts remyelination in multiple sclerosis Melissa Schepers1, 2, Dean Paes1, 2, Assia Tiane1, 2, Evelien Houben1, Olga Bruno3, Chiara Brullo3, Niels Hellings1, Jos Prickaerts2 and Tim Vanmierlo1, 2* 1 University of Hasselt, Belgium 2 School for Mental Health and Neuroscience, Maastricht University, Netherlands 3 Sezione di Chimica del Farmaco, Dipartimento di Farmacia, University of Genova, Italy Progressive multiple sclerosis (pMS) is a chronic demyelinating disorder of the central nervous system (CNS). pMS is featured by failing remyelination processes due to the inability of oligodendrocyte precursor cells (OPC) to differentiate into myelin-forming oligodendrocytes. Phosphodiesterase 4 (PDE4) is a family of enzymes that hydrolyze and inactivate cyclic adenosine monophosphate (cAMP), a second messenger crucially involved in OPC differentiation. We recently found that the aspecific PDE4 inhibitor roflumilast induces in vitro and in vivo remyelination. Yet, the use of aspecific PDE4 inhibitors coincides with emetic side-effects at the repair-inducing dose. Therefore, we hypothesize that selective inhibition of PDE4D promotes remyelination at non-emetic doses. The PDE4D inhibitor Gebr32a (5µM) accelerated in vitro OPC differentiation and showed accelerated ex vivo remyelination in lysolecithin-demyelinated mouse brain slices. Next, 10-week-old male C57bl6 mice were subjected to demyelination in the cuprizone model (6 weeks, 0.3% cuprizone w/w). Upon withdrawal of the cuprizone, mice were treated with either with Gebr32a (7days: 0.1mg/kg or 0.3mg/kg) or vehicle. Compared to vehicle, Gebr32a 0.3mg/kg treatment displayed an enhanced remyelination by yielding an increased expression of myelin basic protein (MBP) in the corpus callosum and dendate gyrus while improving memory performance in the object location task (OLT) . The improved remyelination and spatial memory performance following Gebr32a treatment at a non-emetic dose, prompt us to conclude that PDE4D inhibition boosts the endogenous repair mechanisms in cuprizone fed mice and thereby improves cognitive performances. Keywords: Phosphodiesterase (PDE), Multiple scleorsis (MS), Cognition, oligodendrocyte precursor cell (OPC), CNS repair Conference: 13th National Congress of the Belgian Society for Neuroscience , Brussels, Belgium, 24 May - 24 May, 2019. Presentation Type: Poster presentation Topic: Cellular/Molecular Neuroscience Citation: Schepers M, Paes D, Tiane A, Houben E, Bruno O, Brullo C, Hellings N, Prickaerts J and Vanmierlo T (2019). Phosphodiesterase 4D inhibition boosts remyelination in multiple sclerosis. Front. Neurosci. Conference Abstract: 13th National Congress of the Belgian Society for Neuroscience . doi: 10.3389/conf.fnins.2019.96.00034 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 25 Apr 2019; Published Online: 27 Sep 2019. * Correspondence: Mx. Tim Vanmierlo, University of Hasselt, Hasselt, Belgium, tim.vanmierlo@uhasselt.be Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Melissa Schepers Dean Paes Assia Tiane Evelien Houben Olga Bruno Chiara Brullo Niels Hellings Jos Prickaerts Tim Vanmierlo Google Melissa Schepers Dean Paes Assia Tiane Evelien Houben Olga Bruno Chiara Brullo Niels Hellings Jos Prickaerts Tim Vanmierlo Google Scholar Melissa Schepers Dean Paes Assia Tiane Evelien Houben Olga Bruno Chiara Brullo Niels Hellings Jos Prickaerts Tim Vanmierlo PubMed Melissa Schepers Dean Paes Assia Tiane Evelien Houben Olga Bruno Chiara Brullo Niels Hellings Jos Prickaerts Tim Vanmierlo Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.
The promising anti-angiogenetic properties of previously synthesized pyrazolyl ureas provided the rationale for the synthesis of novel 5-aminopyrazoles 2–5, differently decorated on the pyrazole nucleus. All the derivatives were tested by MTT assays and proved to be non-cytotoxic against eight different tumor cell lines and normal fibroblasts. An EdU proliferation assay was carried out on human foreskin fibroblasts and VEGF stimulated human umbilical vein endothelial cells which confirmed the absence of cytotoxicity of the compounds on human cells up to 20 μM concentration. To evaluate the influence of the newly synthesized pyrazoles on MAPK and PI3K signaling pathways, the phosphorylation of ERK1/2 and Akt was analyzed by Western blots from HFF and HUVEC cell lysates stimulated with growth factors in the presence or absence of the compounds. Pyrazoles 3b and 3c showed a significant inhibition of Akt phosphorylation in both tested cell lines with lower phosphorylation levels than the reference compound GeGe-3 in HUVEC. Furthermore, derivatives 2 and 3 appeared to strongly affect the migration of HFF cells in a wound healing assay, confirming their potential ability to interfere with the angiogenesis process. The new pyrazole library extends the structure-activity relationships of the previously isolated compounds and highlights the attractiveness of this chemical class for pathological cell migration and angiogenesis.
G-protein-coupled receptors (GPCRs) represent a family of druggable targets when treating several diseases and continue to be a leading part of the drug discovery process. Trace amine-associated receptors (TAARs) are GPCRs involved in many physiological functions with TAAR1 having important roles within the central nervous system (CNS). By using homology modeling methods, the responsiveness of TAAR1 to endogenous and synthetic ligands has been explored. In addition, the discovery of different chemo-types as selective murine and/or human TAAR1 ligands has helped in the understanding of the species-specificity preferences. The availability of TAAR1-ligand complexes sheds light on how different ligands bind TAAR1. TAAR5 is considered an olfactory receptor but has specific involvement in some brain functions. In this case, the drug discovery effort has been limited. Here, we review the successful computational efforts developed in the search for novel TAAR1 and TAAR5 ligands. A specific focus on applying structure-based and/or ligand-based methods has been done. We also give a perspective of the experimental data available to guide the future drug design of new ligands, probing species-specificity preferences towards more selective ligands. Hints for applying repositioning approaches are also discussed.
