Screening of Antibiotics against β-amyloid as Anti-amyloidogenic Agents: A Drug Repurposing Approach

Author(s):  
Jahangir Alam ◽  
Varun Jaiswal ◽  
Lalit Sharma

Background: β-amyloid (Aβ) production and aggregation is the main culprit of Alzheimer’s disease (AD). AD is becoming crisis where no treatment available for halting the disease progression. Antibiotics are used not only to treat infections, but also some of the non-contagious diseases and have found active as anti-amyloidogenic agents. Objective: The work aim’s to investigate anti-amyloidogenic activity of antibiotics as re-purposing agents via inhibiting Aβ aggregation and fibril formation employing in-silico and in-vitro approaches. Mehtods: In-silico screening was designed with receptor and ligand preparation, grid formation, docking simulation and its analysis. Thioflavin T-amyloid binding and protease-digestion studies were intended as in-vitro assays. The pharmacological potential of antibiotics as anti-amyloidogenic agents was assessed by these methods. Results: Paromomycin and Neomycin were identified with higher order of estimated free energy of binding in in-silico sreening. In in-vitro screening, paromomycin significantly (p<0.01) reduced the fluorescence intensity and resistance to tryptic degradation of Aβ(1-42) peptides while neomycin had no or little effect (p<0.01) when compared to control. Results from docking and wet lab studies were found in correlation. Conclusion: Paromomycin exhibited higher anti-Aβ aggregating and defibrillogenic activity than neomycin and leaves an indication for further in-vivo testing and could be a future promising anti-amyloidal candidate for the treatment of several amyloidoses.

2018 ◽  
Vol 21 (3) ◽  
pp. 215-221
Author(s):  
Haroon Khan ◽  
Muhammad Zafar ◽  
Helena Den-Haan ◽  
Horacio Perez-Sanchez ◽  
Mohammad Amjad Kamal

Aim and Objective: Lipoxygenase (LOX) enzymes play an important role in the pathophysiology of several inflammatory and allergic diseases including bronchial asthma, allergic rhinitis, atopic dermatitis, allergic conjunctivitis, rheumatoid arthritis and chronic obstructive pulmonary disease. Inhibitors of the LOX are believed to be an ideal approach in the treatment of diseases caused by its over-expression. In this regard, several synthetic and natural agents are under investigation worldwide. Alkaloids are the most thoroughly investigated class of natural compounds with outstanding past in clinically useful drugs. In this article, we have discussed various alkaloids of plant origin that have already shown lipoxygenase inhibition in-vitro with possible correlation in in silico studies. Materials and Methods: Molecular docking studies were performed using MOE (Molecular Operating Environment) software. Among the ten reported LOX alkaloids inhibitors, derived from plant, compounds 4, 2, 3 and 1 showed excellent docking scores and receptor sensitivity. Result and Conclusion: These compounds already exhibited in vitro lipoxygenase inhibition and the MOE results strongly correlated with the experimental results. On the basis of these in vitro assays and computer aided results, we suggest that these compounds need further detail in vivo studies and clinical trial for the discovery of new more effective and safe lipoxygenase inhibitors. In conclusion, these results might be useful in the design of new and potential lipoxygenase (LOX) inhibitors.


2019 ◽  
Vol 12 (1) ◽  
pp. 58-71 ◽  
Author(s):  
Suchitil Rivera-Marrero ◽  
Laura Fernández-Maza ◽  
Samila León-Chaviano ◽  
Marquiza Sablón-Carrazana ◽  
Alberto Bencomo-Martínez ◽  
...  

Background: Alzheimer’s disease (AD) is the most common form of dementia. Neuroimaging methods have widened the horizons for AD diagnosis and therapy. The goals of this work are the synthesis of 2-(3-fluoropropyl)-6-methoxynaphthalene (5) and its [18F]-radiolabeled counterpart ([18F]Amylovis), the in silico and in vitro comparative evaluations of [18F]Amylovis and [11C]Pittsburg compound B (PIB) and the in vivo preclinical evaluation of [18F]Amylovis in transgenic and wild mice. </p><p> Methods: Iron-catalysis cross coupling reaction, followed by fluorination and radiofluorination steps were carried out to obtain 5 and 18F-Amylovis. Protein/A&#223; plaques binding, biodistribution, PET/CT Imaging and immunohistochemical studies were conducted in healthy/transgenic mice. </p><p> Results: The synthesis of 5 was successful obtained. Comparative in silico studies predicting that 5 should have affinity to the A&#946;-peptide, mainly through &#960;-&#960; interactions. According to a dynamic simulation study the ligand-A&#946; peptide complexes are stable in simulation-time (&#916;G = -5.31 kcal/mol). [18F]Amylovis was obtained with satisfactory yield, high radiochemical purity and specific activity. The [18F]Amylovis log Poct/PBS value suggests its potential ability for crossing the blood brain barrier (BBB). According to in vitro assays, [18F]Amylovis has an adequate stability in time. Higher affinity to A&#946; plaques were found for [18F]Amylovis (Kd 0.16 nmol/L) than PIB (Kd 8.86 nmol/L) in brain serial sections of 3xTg-AD mice. Biodistribution in healthy mice showed that [18F]Amylovis crosses the BBB with rapid uptake (7 %ID/g at 5 min) and good washout (0.11&#177;0.03 %ID/g at 60 min). Comparative PET dynamic studies of [18F]Amylovis in healthy and transgenic APPSwe/PS1dE9 mice, revealed a significant high uptake in the mice model. </p><p> Conclusion: The in silico, in vitro and in vivo results justify that [18F]Amylovis should be studied as a promissory PET imaging agent to detect the presence of A&#946; senile plaques.


2020 ◽  
Vol 3 (4) ◽  
pp. 989-1000
Author(s):  
Mustapha Abdullahi ◽  
Shola Elijah Adeniji

AbstractMolecular docking simulation of thirty-five (35) molecules of N-(2-phenoxy)ethyl imidazo[1,2-a]pyridine-3-carboxamide (IPA) with Mycobacterium tuberculosis target (DNA gyrase) was carried out so as to evaluate their theoretical binding affinities. The chemical structure of the molecules was accurately drawn using ChemDraw Ultra software, then optimized at density functional theory (DFT) using Becke’s three-parameter Lee–Yang–Parr hybrid functional (B3LYP/6-311**) basis set in a vacuum of Spartan 14 software. Subsequently, the docking operation was carried out using PyRx virtual screening software. Molecule 35 (M35) with the highest binding affinity of − 7.2 kcal/mol was selected as the lead molecule for structural modification which led to the development of four (4) newly hypothetical molecules D1, D2, D3 and D4. In addition, the D4 molecule with the highest binding affinity value of − 9.4 kcal/mol formed more H-bond interactions signifying better orientation of the ligand in the binding site compared to M35 and isoniazid standard drug. In-silico ADME and drug-likeness prediction of the molecules showed good pharmacokinetic properties having high gastrointestinal absorption, orally bioavailable, and less toxic. The outcome of the present research strengthens the relevance of these compounds as promising lead candidates for the treatment of multidrug-resistant tuberculosis which could help the medicinal chemists and pharmaceutical professionals in further designing and synthesis of more potent drug candidates. Moreover, the research also encouraged the in vivo and in vitro evaluation study for the proposed designed compounds to validate the computational findings.


2020 ◽  
Author(s):  
Tamara Rubilar ◽  
Elena Susana Barbieri ◽  
Ayelén Gázquez ◽  
Marisa Avaro ◽  
Mercedes Vera-Piombo ◽  
...  

The SARS-CoV-2 outbreak has spread rapidly and globally generating a new coronavirus disease (COVID-19) since December 2019 that turned into a pandemic. Effective drugs are urgently needed and drug repurposing strategies offer a promising alternative to dramatically shorten the process of traditional de novo development. Based on their antiviral uses, the potential affinity of sea urchin pigments to bind main protease (Mpro) of SARS-CoV-2 was evaluated in silico. Docking analysis was used to test the potential of these sea urchin pigments as therapeutic and antiviral agents. All pigment compounds presented high molecular affinity to Mpro protein. However, the 1,4-naphtoquinones polihydroxilate (Spinochrome A and Echinochrome A) showed high affinity to bind around the Mpro´s pocket target by interfering with proper folding of the protein mainly through an H-bond with Glu166 residue. This interaction represents a potential blockage of this protease´s activity. All these results provide novel information regarding the uses of sea urchin pigments as antiviral drugs and suggest the need for further in vitro and in vivo analysis to expand all therapeutic uses against SARS-CoV-2. <br>


Author(s):  
Tamara Rubilar ◽  
Elena Susana Barbieri ◽  
Ayelén Gázquez ◽  
Marisa Avaro ◽  
Mercedes Vera-Piombo ◽  
...  

The SARS-CoV-2 outbreak has spread rapidly and globally generating a new coronavirus disease (COVID-19) since December 2019 that turned into a pandemic. Effective drugs are urgently needed and drug repurposing strategies offer a promising alternative to dramatically shorten the process of traditional de novo development. Based on their antiviral uses, the potential affinity of sea urchin pigments to bind main protease (Mpro) of SARS-CoV-2 was evaluated in silico. Docking analysis was used to test the potential of these sea urchin pigments as therapeutic and antiviral agents. All pigment compounds presented high molecular affinity to Mpro protein. However, the 1,4-naphtoquinones polihydroxilate (Spinochrome A and Echinochrome A) showed high affinity to bind around the Mpro´s pocket target by interfering with proper folding of the protein mainly through an H-bond with Glu166 residue. This interaction represents a potential blockage of this protease´s activity. All these results provide novel information regarding the uses of sea urchin pigments as antiviral drugs and suggest the need for further in vitro and in vivo analysis to expand all therapeutic uses against SARS-CoV-2. <br>


2020 ◽  
Vol 175 (2) ◽  
pp. 236-250 ◽  
Author(s):  
Jonathan T Haselman ◽  
Jennifer H Olker ◽  
Patricia A Kosian ◽  
Joseph J Korte ◽  
Joseph A Swintek ◽  
...  

Abstract Chemical safety evaluation is in the midst of a transition from traditional whole-animal toxicity testing to molecular pathway-based in vitro assays and in silico modeling. However, to facilitate the shift in reliance on apical effects for risk assessment to predictive surrogate metrics having characterized linkages to chemical mechanisms of action, targeted in vivo testing is necessary to establish these predictive relationships. In this study, we demonstrate a means to predict thyroid-related metamorphic success in the model amphibian Xenopus laevis using relevant biochemical measurements during early prometamorphosis. The adverse outcome pathway for thyroperoxidase inhibition leading to altered amphibian metamorphosis was used to inform a pathway-based in vivo study design that generated response-response relationships. These causal relationships were used to develop Bayesian probabilistic network models that mathematically determine conditional dependencies between biochemical nodes and support the predictive capability of the biochemical profiles. Plasma thyroxine concentrations were the most predictive of metamorphic success with improved predictivity when thyroid gland sodium-iodide symporter gene expression levels (a compensatory response) were used in conjunction with plasma thyroxine as an additional regressor. Although thyroid-mediated amphibian metamorphosis has been studied for decades, this is the first time a predictive relationship has been characterized between plasma thyroxine and metamorphic success. Linking these types of biochemical surrogate metrics to apical outcomes is vital to facilitate the transition to the new paradigm of chemical safety assessments.


1981 ◽  
Author(s):  
N Pancham ◽  
M A Fournel ◽  
M H Coan

In FVIII:C deficient persons, who also have circulating antibodies to the molecule, replacement therapy with FVIII concentrates elevates the antibody level and is of limited or no value. Treatment with prothrombin complex concentrates, however, has had varying degrees of success in these patients depending on the significance of the bleed.Currently available Anti-Inhibitor Coagulant Concentrates (AICC), containing factors II, VII, IX, and X in their nonactivated as well as activated forms, have been shown to be effective in controlling bleeds in some of these patients.Two commercially available AICC products and two research preparations were evaluated using conventional in vitro clotting techniques. In vivo assays were also performed in animal systems using the Wessler venous stasis assay. Despite similarities by in vitro assays, striking differences exist in the results obtained using the animal systems. As shown by the Wessler venous stasis assay for in vivo testing, the materials are much more active (at least an order of magnitude) than currently manufactured factor IX concentrates.In vitro clotting assays that are now available (namely factors II, VII, IX, X, IIa, Xa, NAPTT, FVIII correctional activity, and FVIII inhibitor bypassing activity assays) do not necessarily predict the in vivo efficacy of these AICC products. Furthermore, there is no correlation between the FVIII correctional activity and the FVIII inhibitor bypassing activity assays which are now being used to monitor these preparations.


Author(s):  
James W. Firman ◽  
Mark T. D. Cronin ◽  
Philip H. Rowe ◽  
Elizaveta Semenova ◽  
John E. Doe

AbstractThere exists consensus that the traditional means by which safety of chemicals is assessed—namely through reliance upon apical outcomes obtained following in vivo testing—is increasingly unfit for purpose. Whilst efforts in development of suitable alternatives continue, few have achieved levels of robustness required for regulatory acceptance. An array of “new approach methodologies” (NAM) for determining toxic effect, spanning in vitro and in silico spheres, have by now emerged. It has been suggested, intuitively, that combining data obtained from across these sources might serve to enhance overall confidence in derived judgment. This concept may be formalised in the “tiered assessment” approach, whereby evidence gathered through a sequential NAM testing strategy is exploited so to infer the properties of a compound of interest. Our intention has been to provide an illustration of how such a scheme might be developed and applied within a practical setting—adopting for this purpose the endpoint of rat acute oral lethality. Bayesian statistical inference is drawn upon to enable quantification of degree of confidence that a substance might ultimately belong to one of five LD50-associated toxicity categories. Informing this is evidence acquired both from existing in silico and in vitro resources, alongside a purposely-constructed random forest model and structural alert set. Results indicate that the combination of in silico methodologies provides moderately conservative estimations of hazard, conducive for application in safety assessment, and for which levels of certainty are defined. Accordingly, scope for potential extension of approach to further toxicological endpoints is demonstrated.


2021 ◽  
Vol 28 ◽  
Author(s):  
Joanda Paolla Raimundo e Silva ◽  
Chonny Alexander Herrera Acevedo ◽  
Thalisson Amorim de Souza ◽  
Renata Priscila Barros de Menezes ◽  
Zoe L. Sessions ◽  
...  

Background: Natural products are useful agents for the discovery of new lead-compounds and effective drugs to combat coronaviruses (CoV). Objective: The present work provides an overview of natural substances, plant extracts, and essential oils as potential antiSARS-CoV agents. In addition, this work evaluates their drug-like properties which are essential in the selection of compounds in order to accelerate the drug development process. Methods: The search was carried out using PubMed, ScienceDirect and SciFinder. Articles addressing plant-based natural products as potential SARS-CoV or SARS-CoV-2 agents within the last seventeen years were analyzed and selected. The descriptors for Chemometrics analyzes were obtained in alvaDesc and the principal component analyzes (PCA) were carried out in SIMCA version 13.0. Results: Based on in vitro assays and computational analyzes, this review covers twenty nine medicinal plant species and more than 300 isolated substances as potential anti-coronavirus agents. Among them, flavonoids and terpenes were the most promising compound classes. In silico analyses of drug-like properties corroborate these findings and indicate promising candidates for in vitro and in vivo studies to validate their activity. Conclusion: This paper highlights the role of ethnopharmacology in drug discovery and simulates the use of integrative (in silico/ in vitro) and chemocentric approaches to strengthen current studies and guide future research in the field of antivirals agents.


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