scholarly journals Accelerating Drug Discovery Efforts for Trypanosomatidic Infections Using an Integrated Transnational Academic Drug Discovery Platform

2019 ◽  
Vol 24 (3) ◽  
pp. 346-361 ◽  
Author(s):  
Carolina B. Moraes ◽  
Gesa Witt ◽  
Maria Kuzikov ◽  
Bernhard Ellinger ◽  
Theodora Calogeropoulou ◽  
...  

According to the World Health Organization, more than 1 billion people are at risk of or are affected by neglected tropical diseases. Examples of such diseases include trypanosomiasis, which causes sleeping sickness; leishmaniasis; and Chagas disease, all of which are prevalent in Africa, South America, and India. Our aim within the New Medicines for Trypanosomatidic Infections project was to use (1) synthetic and natural product libraries, (2) screening, and (3) a preclinical absorption, distribution, metabolism, and excretion–toxicity (ADME-Tox) profiling platform to identify compounds that can enter the trypanosomatidic drug discovery value chain. The synthetic compound libraries originated from multiple scaffolds with known antiparasitic activity and natural products from the Hypha Discovery MycoDiverse natural products library. Our focus was first to employ target-based screening to identify inhibitors of the protozoan Trypanosoma brucei pteridine reductase 1 ( TbPTR1) and second to use a Trypanosoma brucei phenotypic assay that made use of the T. brucei brucei parasite to identify compounds that inhibited cell growth and caused death. Some of the compounds underwent structure-activity relationship expansion and, when appropriate, were evaluated in a preclinical ADME-Tox assay panel. This preclinical platform has led to the identification of lead-like compounds as well as validated hits in the trypanosomatidic drug discovery value chain.

Marine Drugs ◽  
2020 ◽  
Vol 18 (4) ◽  
pp. 187 ◽  
Author(s):  
María Álvarez-Bardón ◽  
Yolanda Pérez-Pertejo ◽  
César Ordóñez ◽  
Daniel Sepúlveda-Crespo ◽  
Nestor M. Carballeira ◽  
...  

Neglected Tropical Diseases (NTD) represent a serious threat to humans, especially for those living in poor or developing countries. Almost one-sixth of the world population is at risk of suffering from these diseases and many thousands die because of NTDs, to which we should add the sanitary, labor and social issues that hinder the economic development of these countries. Protozoan-borne diseases are responsible for more than one million deaths every year. Visceral leishmaniasis, Chagas disease or sleeping sickness are among the most lethal NTDs. Despite not being considered an NTD by the World Health Organization (WHO), malaria must be added to this sinister group. Malaria, caused by the apicomplexan parasite Plasmodium falciparum, is responsible for thousands of deaths each year. The treatment of this disease has been losing effectiveness year after year. Many of the medicines currently in use are obsolete due to their gradual loss of efficacy, their intrinsic toxicity and the emergence of drug resistance or a lack of adherence to treatment. Therefore, there is an urgent and global need for new drugs. Despite this, the scant interest shown by most of the stakeholders involved in the pharmaceutical industry makes our present therapeutic arsenal scarce, and until recently, the search for new drugs has not been seriously addressed. The sources of new drugs for these and other pathologies include natural products, synthetic molecules or repurposing drugs. The most frequent sources of natural products are microorganisms, e.g., bacteria, fungi, yeasts, algae and plants, which are able to synthesize many drugs that are currently in use (e.g. antimicrobials, antitumor, immunosuppressants, etc.). The marine environment is another well-established source of bioactive natural products, with recent applications against parasites, bacteria and other pathogens which affect humans and animals. Drug discovery techniques have rapidly advanced since the beginning of the millennium. The combination of novel techniques that include the genetic modification of pathogens, bioimaging and robotics has given rise to the standardization of High-Performance Screening platforms in the discovery of drugs. These advancements have accelerated the discovery of new chemical entities with antiparasitic effects. This review presents critical updates regarding the use of High-Throughput Screening (HTS) in the discovery of drugs for NTDs transmitted by protozoa, including malaria, and its application in the discovery of new drugs of marine origin.


Molecules ◽  
2019 ◽  
Vol 24 (2) ◽  
pp. 314 ◽  
Author(s):  
Joana Araújo ◽  
Carla Fernandes ◽  
Madalena Pinto ◽  
Maria Tiritan

According to the World Health Organization, the exacerbated use of antibiotics worldwide is increasing multi-resistant infections, especially in the last decade. Xanthones are a class of compounds receiving great interest in drug discovery and development that can be found as natural products or obtained by synthesis. Many derivatives of xanthones are chiral and associated with relevant biological activities, including antimicrobial. The aim of this review is to compile information about chiral derivatives of xanthones from natural sources and their synthesized examples with antimicrobial activity.


2013 ◽  
Vol 19 (3) ◽  
pp. 335-343 ◽  
Author(s):  
Kelly L. Johnston ◽  
Louise Ford ◽  
Mark J. Taylor

Neglected tropical diseases (NTDs) are a group of 17 diseases that typically affect poor people in tropical countries. Each has been neglected for decades in terms of funding, research, and policy, but the recent grouping of them into one unit, which can be targeted using integrated control measures, together with increased advocacy has helped to place them on the global health agenda. The World Health Organization has set ambitious goals to control or eliminate 10 NTDs by 2020 and launched a roadmap in January 2012 to guide this global plan. The result of the launch meeting, which brought together representatives from the pharmaceutical industry, donors, and politicians, was the London Declaration: a series of commitments to provide more drugs, research, and funds to achieve the 2020 goals. Drug discovery and development for these diseases are extremely challenging, and this article highlights these challenges in the context of the London Declaration, before focusing on an example of a drug discovery and development program for the NTDs onchocerciasis and lymphatic filariasis (the anti- Wolbachia consortium, A·WOL).


2019 ◽  
Vol 20 (12) ◽  
pp. 1295-1314 ◽  
Author(s):  
Pone Kamdem Boniface ◽  
Ferreira Igne Elizabeth

Objective: Human African Trypanosomiasis (HAT), also known as sleeping sickness is one of the 20 neglected tropical diseases listed by the World Health Organization, which lead to death if left untreated. This disease is caused by Trypanosoma brucei gambiense, which is the chronic form of the disease present in western and central Africa, and by T. brucei rhodesiense, which is the acute form of the disease located in eastern and southern Africa. Many reports have highlighted the effectiveness of flavonoid-based compounds against T. brucei. Methods: A literature search was conducted for naturally occurring and synthetic anti-T brucei flavonoids by referencing textbooks and scientific databases (SciFinder, PubMed, Science Direct, Wiley, ACS, SciELO, Google Scholar, Springer, among others) from their inception until February 2019. Results: The present review summarizes the current standings and perspectives for the use of flavonoids as lead compounds for the potential treatment of HAT. Conclusion: Flavonoids isolated from different parts of plants and species were reported to exhibit moderate to high in vitro antitrypanosomal activity against T. brucei. In addition, synthetic flavonoids revealed anti-T. brucei activity. Molecular interactions of bioactive flavonoids with T. brucei protein targets showed promising results.


2020 ◽  
Vol 27 ◽  
Author(s):  
Kush K. Maheshwari ◽  
Debasish Bandyopadhyay

Background: Neglected tropical diseases (NTDs) affect a huge population of the world and majority of the victims belong to the poor community of the developing countries. Until now, the World Health Organization (WHO) has identified 20 tropical diseases as NTDs that must be addressed with high priority. However, many heterocyclic scaffolds have demonstrated potent therapeutic activity against several NTDs. Objective: There are three major objectives: (1) To discuss the causes, symptoms, and current status of all the 20 NTDs; (2) To explore the available heterocyclic drugs, and their mechanism of actions (if known) that are being used to treat NTDs; (3) To develop general awareness on NTDs among the medicinal/health research community and beyond. Methods: The 20 NTDs have been discussed according to their alphabetic orders along with the possible heterocyclic remedies. Current status of treatment with an emphasis on the heterocyclic drugs (commercially available and investigational) has been outlined. In addition, brief discussion of the impacts of NTDs on socio-economic condition is included. Results: NTDs are often difficult to diagnose and the problem is worsened by the unhealthy hygiene, improper awareness, and inadequate healthcare in the developing countries where these diseases primarily affect poor people. The statistics include duration of suffering, numbers affected, and access to healthcare and medication. The mechanism of actions of various heterocyclic drugs, if reported, have been briefly summarized. Conclusion: Scientists and pharmaceutical corporations should allocate more resources to reveal the in-depth mechanism of actions of many heterocyclic drugs that are currently being used for the treatment of NTDs. Analysis of current heterocyclic compounds and development of new medications can help in the fight to reduce/remove the devastating effects of NTDs. An opinion-based concise review has been presented. Based on available literature, this is the first effect to present all the 20 NTDs and related heterocyclic compounds under the same umbrella.


2020 ◽  
Vol 14 (2) ◽  
pp. 134-144 ◽  
Author(s):  
Matthew P. Ameh ◽  
Mamman Mohammed ◽  
Yusuf P. Ofemile ◽  
Magaji G. Mohammed ◽  
Ada Gabriel ◽  
...  

Background: The World Health Organization included snakebite envenomation among Neglected Tropical Diseases in 2017. The importance of natural products from plants is enormous, given that most prescribed drugs originate from plants. Among this is Mucuna pruriens and Mimosa pudica, with many registered patents asserting their health benefits. Objective: This study investigated the in vitro neutralizing effects of Mucuna pruriens seed and Mimosa pudica root extracts on venoms of Naja nigricollis and Bitis arietans. Methods: In mice, the LD50 and phytochemical analysis of M. pruriens and M. pudica plant extracts were carried out prior to the evaluation of their haemolytic and fibrinolytic effect. Their effects on the activities of phospholipase A2 (PLA2) were also assessed. Results: At a concentration of 50 mg/ml, both plant extracts were found to neutralize the fibrinolytic activity of N. nigricollis, but 400 mg/ml was required to neutralize the fibrinolytic activity of B. arietans. In haemolytic studies, 50 mg/ml concentration of M. pruriens extract suppressed haemolysis caused by N. nigricollis venom by 70% but at the same concentration, M. pudica extract reduced haemolysis by 49.4%. M. pruriens, at 50 mg/ml concentration, only inhibited phospholipase A2 activity by 7.7% but higher concentrations up to 400mg/ml had no effect against the venom of N. nigricollis; at 200 mg/ml. M. pudica extract inhibited PLA2 activity by 23%. Conclusion: The results suggest that M. pruriens and M. pudica may be considered as promising antivenom agents for people living in a snake-bite prone environment.


Biomolecules ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 458
Author(s):  
Emmanuel Broni ◽  
Samuel K. Kwofie ◽  
Seth O. Asiedu ◽  
Whelton A. Miller ◽  
Michael D. Wilson

The huge burden of leishmaniasis caused by the trypanosomatid protozoan parasite Leishmania is well known. This illness was included in the list of neglected tropical diseases targeted for elimination by the World Health Organization. However, the increasing evidence of resistance to existing antimonial drugs has made the eradication of the disease difficult to achieve, thus warranting the search for new drug targets. We report here studies that used computational methods to identify inhibitors of receptors from natural products. The cell division cycle-2-related kinase 12 (CRK12) receptor is a plausible drug target against Leishmania donovani. This study modelled the 3D molecular structure of the L. donovani CRK12 (LdCRK12) and screened for small molecules with potential inhibitory activity from African flora. An integrated library of 7722 African natural product-derived compounds and known inhibitors were screened against the LdCRK12 using AutoDock Vina after performing energy minimization with GROMACS 2018. Four natural products, namely sesamin (NANPDB1649), methyl ellagic acid (NANPDB1406), stylopine (NANPDB2581), and sennecicannabine (NANPDB6446) were found to be potential LdCRK12 inhibitory molecules. The molecular docking studies revealed two compounds NANPDB1406 and NANPDB2581 with binding affinities of −9.5 and −9.2 kcal/mol, respectively, against LdCRK12 which were higher than those of the known inhibitors and drugs, including GSK3186899, amphotericin B, miltefosine, and paromomycin. All the four compounds were predicted to have inhibitory constant (Ki) values ranging from 0.108 to 0.587 μM. NANPDB2581, NANPDB1649 and NANPDB1406 were also predicted as antileishmanial with Pa and Pi values of 0.415 and 0.043, 0.391 and 0.052, and 0.351 and 0.071, respectively. Molecular dynamics simulations coupled with molecular mechanics Poisson–Boltzmann surface area (MM/PBSA) computations reinforced their good binding mechanisms. Most compounds were observed to bind in the ATP binding pocket of the kinase domain. Lys488 was predicted as a key residue critical for ligand binding in the ATP binding pocket of the LdCRK12. The molecules were pharmacologically profiled as druglike with inconsequential toxicity. The identified molecules have scaffolds that could form the backbone for fragment-based drug design of novel leishmanicides but warrant further studies to evaluate their therapeutic potential.


Biomolecules ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1518 ◽  
Author(s):  
Ana L. Chávez-Hernández ◽  
Norberto Sánchez-Cruz ◽  
José L. Medina-Franco

Natural products and semi-synthetic compounds continue to be a significant source of drug candidates for a broad range of diseases, including coronavirus disease 2019 (COVID-19), which is causing the current pandemic. Besides being attractive sources of bioactive compounds for further development or optimization, natural products are excellent substrates of unique substructures for fragment-based drug discovery. To this end, fragment libraries should be incorporated into automated drug design pipelines. However, public fragment libraries based on extensive collections of natural products are still limited. Herein, we report the generation and analysis of a fragment library of natural products derived from a database with more than 400,000 compounds. We also report fragment libraries of a large food chemical database and other compound datasets of interest in drug discovery, including compound libraries relevant for COVID-19 drug discovery. The fragment libraries were characterized in terms of content and diversity.


Author(s):  
Tommaso C. Bulfone ◽  
Stephen P. Samuel ◽  
Philip L. Bickler ◽  
Matthew R. Lewin

The World Health Organization (WHO) recently added snakebite envenoming to the priority list of Neglected Tropical Diseases (NTD). It is thought that ~75% of mortality following snakebite occurs outside the hospital setting, making the temporal gap between a bite and antivenom administration a major therapeutic challenge. Small molecule therapeutics (SMTs) have been proposed as potential pre-referral treatments for snakebite to help address this gap. Herein, we discuss the characteristics, potential uses and development of SMTs as potential treatments for snakebite envenomation. We focus on SMTs that are secretory phospholipase A2 (sPLA2) inhibitors and metalloprotease (MP) inhibitors.


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