scholarly journals Lipid and fatty acid metabolism in trypanosomatids

2021 ◽  
Vol 8 (11) ◽  
pp. 262-275
Author(s):  
Giovana Parreira de Aquino ◽  
Marco Antonio Mendes Gomes ◽  
Roberto Köpke Salinas ◽  
Maria Fernanda Laranjeira-Silva
Keyword(s):  
De Novo ◽  
Neglected Tropical Diseases ◽  
Treatment Options ◽  
Life Cycles ◽  
Protozoan Parasites ◽  
Life Cycle Stages ◽  
Leishmania Spp ◽  
Causative Agents ◽  
Major Energy Source ◽  
Antiparasitic Drugs

Trypanosomiases and leishmaniases are neglected tropical diseases that have been spreading to previously non-affected areas in recent years. Identification of new chemotherapeutics is needed as there are no vaccines and the currently available treatment options are highly toxic and often ineffective. The causative agents for these diseases are the protozoan parasites of the Trypanosomatidae family, and they alternate between invertebrate and vertebrate hosts during their life cycles. Hence, these parasites must be able to adapt to different environments and compete with their hosts for several essential compounds, such as amino acids, vitamins, ions, carbohydrates, and lipids. Among these nutrients, lipids and fatty acids (FAs) are essential for parasite survival. Trypanosomatids require massive amounts of FAs, and they can either synthesize FAs de novo or scavenge them from the host. Moreover, FAs are the major energy source during specific life cycle stages of T. brucei, T. cruzi, and Leishmania. Therefore, considering the distinctive features of FAs metabolism in trypanosomatids, these pathways could be exploited for the development of novel antiparasitic drugs. In this review, we highlight specific aspects of lipid and FA metabolism in the protozoan parasites T. brucei, T. cruzi, and Leishmania spp., as well as the pathways that have been explored for the development of new chemotherapies.

scholarly journals Bisphosphonate-Based Molecules as Potential New Antiparasitic Drugs

Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2602 ◽  
Author(s):  
Joice Castelo Branco Santos ◽  
Jonathas Alves de Melo ◽  
Sweta Maheshwari ◽  
Wendy Marina Toscano Queiroz de Medeiros ◽  
Johny Wysllas de Freitas Oliveira ◽  
...  
Keyword(s):  
Chagas Disease ◽  
Mevalonate Pathway ◽  
Neglected Tropical Diseases ◽  
New Drugs ◽  
Synthesis Process ◽  
Antiparasitic Activity ◽  
The World ◽  
Leishmania Spp ◽  
Antiparasitic Drugs ◽  
Antiparasitic Agents

Neglected tropical diseases such as Chagas disease and leishmaniasis affect millions of people around the world. Both diseases affect various parts of the globe and drugs traditionally used in therapy against these diseases have limitations, especially with regard to low efficacy and high toxicity. In this context, the class of bisphosphonate-based compounds has made significant advances regarding the chemical synthesis process as well as the pharmacological properties attributed to these compounds. Among this spectrum of pharmacological activity, bisphosphonate compounds with antiparasitic activity stand out, especially in the treatment of Chagas disease and leishmaniasis caused by Trypanosoma cruzi and Leishmania spp., respectively. Some bisphosphonate compounds can inhibit the mevalonate pathway, an essential metabolic pathway, by interfering with the synthesis of ergosterol, a sterol responsible for the growth and viability of these parasites. Therefore, this review aims to present the information about the importance of these compounds as antiparasitic agents and as potential new drugs to treat Chagas disease and leishmaniasis.

scholarly journals Microorganisms as a Potential Source of Molecules to Control Trypanosomatid Diseases

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1388
Author(s):  
Manuel Jesús Chan-Bacab ◽  
María Manuela Reyes-Estebanez ◽  
Juan Carlos Camacho-Chab ◽  
Benjamín Otto Ortega-Morales
Keyword(s):  
Heterotrophic Bacteria ◽  
Neglected Tropical Diseases ◽  
New Drugs ◽  
Future Research ◽  
Fungal Metabolites ◽  
Lead Compounds ◽  
Current State ◽  
Causative Agents ◽  
Antiparasitic Drugs ◽  
New Generation

Trypanosomatids are the causative agents of leishmaniasis and trypanosomiasis, which affect about 20 million people in the world’s poorest countries, leading to 95,000 deaths per year. They are often associated with malnutrition, weak immune systems, low quality housing, and population migration. They are generally recognized as neglected tropical diseases. New drugs against these parasitic protozoa are urgently needed to counteract drug resistance, toxicity, and the high cost of commercially available drugs. Microbial bioprospecting for new molecules may play a crucial role in developing a new generation of antiparasitic drugs. This article reviews the current state of the available literature on chemically defined metabolites of microbial origin that have demonstrated antitrypanosomatid activity. In this review, bacterial and fungal metabolites are presented; they originate from a range of microorganisms, including cyanobacteria, heterotrophic bacteria, and filamentous fungi. We hope to provide a useful overview for future research to identify hits that may become the lead compounds needed to accelerate the discovery of new drugs against trypanosomatids.

scholarly journals Social science and the complexity of tropical medicine

2020 ◽  
Vol 5 (2) ◽  
Author(s):  
David Gaus
Keyword(s):  
Social Science ◽  
Yellow Fever ◽  
Viral Infections ◽  
Neglected Tropical Diseases ◽  
Life Cycles ◽  
Tropical Medicine ◽  
Tropical Diseases ◽  
Treatment And Prevention ◽  
Causative Agents ◽  
Tropical Climates

In the name of biomedicine, humankind has witnessed incredible advances in causative agents, life cycles, treatment, and prevention of many population-crushing parasitic, bacterial, and viral infections such as Malaria, Typhoid, and Yellow Fever. Originally designed to protect imperial troops in tropical climates from maladies previously unknown in the fatherland, the now anachronistic term "tropical medicine" attempts to capture the interplay of local culture, poverty, and the environment - areas where biomedicine encounters major limitations. The existence of the thirteen "Neglected Tropical Diseases" (NTDs) responsible for disabling conditions that mostly affect the world's poorest populations, are a testament to the shortcomings of biomedically-driven tropical medicine.

scholarly journals The Truman Show for protozoan parasites: A review of in vitro cultivation platforms

2021 ◽  
Vol 15 (8) ◽  
pp. e0009668
Author(s):  
Smita Sutrave ◽  
Martin Heinrich Richter
Keyword(s):  
Disease Transmission ◽  
New Technologies ◽  
Neglected Tropical Diseases ◽  
Severe Disease ◽  
In Vitro Models ◽  
Life Cycles ◽  
In Vitro Cultivation ◽  
Protozoan Parasites ◽  
In Vivo Models

Protozoan parasites are responsible for severe disease and suffering in humans worldwide. Apart from disease transmission via insect vectors and contaminated soil, food, or water, transmission may occur congenitally or by way of blood transfusion and organ transplantation. Several recent outbreaks associated with fresh produce and potable water emphasize the need for vigilance and monitoring of protozoan parasites that cause severe disease in humans globally. Apart from the tropical parasite Plasmodium spp., other protozoa causing debilitating and fatal diseases such as Trypanosoma spp. and Naegleria fowleri need to be studied in more detail. Climate change and socioeconomic issues such as migration continue to be major drivers for the spread of these neglected tropical diseases beyond endemic zones. Due to the complex life cycles of protozoa involving multiple hosts, vectors, and stringent growth conditions, studying these parasites has been challenging. While in vivo models may provide insights into host–parasite interaction, the ethical aspects of laboratory animal use and the challenge of ready availability of parasite life stages underline the need for in vitro models as valid alternatives for culturing and maintaining protozoan parasites. To our knowledge, this review is the first of its kind to highlight available in vitro models for protozoa causing highly infectious diseases. In recent years, several research efforts using new technologies such as 3D organoid and spheroid systems for protozoan parasites have been introduced that provide valuable tools to advance complex culturing models and offer new opportunities toward the advancement of parasite in vitro studies. In vitro models aid scientists and healthcare providers in gaining insights into parasite infection biology, ultimately enabling the use of novel strategies for preventing and treating these diseases.

scholarly journals The Functioning of Na+-ATPases from Protozoan Parasites: Are These Pumps Targets for Antiparasitic Drugs?

Cells ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 2225
Author(s):  
Claudia F. Dick ◽  
José Roberto Meyer-Fernandes ◽  
Adalberto Vieyra
Keyword(s):  
Plasmodium Falciparum ◽  
Toxoplasma Gondii ◽  
Mammalian Cells ◽  
Life Cycles ◽  
Therapeutic Interventions ◽  
Potential Candidate ◽  
Protozoan Parasites ◽  
Antiparasitic Drugs ◽  
P Type ◽  
Structural Homologue

The ENA ATPases (from exitus natru: the exit of sodium) belonging to the P-type ATPases are structurally very similar to the sarco/endoplasmic reticulum Ca2+-ATPase (SERCA); they exchange Na+ for H+ and, therefore, are also known as Na+-ATPases. ENA ATPases are required in alkaline milieu, as in the case for Aspergillus, where other transporters cannot mediate an uphill Na+ efflux. They are also important for salt tolerance, as described for Arabidopsis. During their life cycles, protozoan parasites might encounter a high pH environment, thus allowing consideration of ENA ATPases as possible targets for controlling certain severe parasitic diseases, such as Chagas’ Disease. Phylogenetic analysis has now shown that, besides the types IIA, IIB, IIC, and IID P-type ATPases, there exists a 5th subgroup of ATPases classified as ATP4-type ATPases, found in Plasmodium falciparum and Toxoplasma gondii. In malaria, for example, some drugs targeting PfATP4 destroy Na+ homeostasis; these drugs, which include spiroindolones, are now in clinical trials. The ENA P-type (IID P-type ATPase) and ATP4-type ATPases have no structural homologue in mammalian cells, appearing only in fungi, plants, and protozoan parasites, e.g., Trypanosoma cruzi, Leishmania sp., Toxoplasma gondii, and Plasmodium falciparum. This exclusivity makes Na+-ATPase a potential candidate for the biologically-based design of new therapeutic interventions; for this reason, Na+-ATPases deserves more attention.

scholarly journals ApiAP2 Transcription Factors in Apicomplexan Parasites

Pathogens ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 47 ◽  
Author(s):  
Myriam Jeninga ◽  
Jennifer Quinn ◽  
Michaela Petter
Keyword(s):  
Transcription Factor ◽  
Life Cycle ◽  
Life Cycles ◽  
Transcription Factor Family ◽  
Important Species ◽  
Apicomplexan Parasites ◽  
Life Cycle Stages ◽  
Parasite Plasmodium ◽  
Causative Agents ◽  
Parasite Biology

Apicomplexan parasites are protozoan organisms that are characterised by complex life cycles and they include medically important species, such as the malaria parasite Plasmodium and the causative agents of toxoplasmosis (Toxoplasma gondii) and cryptosporidiosis (Cryptosporidium spp.). Apicomplexan parasites can infect one or more hosts, in which they differentiate into several morphologically and metabolically distinct life cycle stages. These developmental transitions rely on changes in gene expression. In the last few years, the important roles of different members of the ApiAP2 transcription factor family in regulating life cycle transitions and other aspects of parasite biology have become apparent. Here, we review recent progress in our understanding of the different members of the ApiAP2 transcription factor family in apicomplexan parasites.

Naphthoquinones and derivatives for chemotherapy: perspectives and limitations of their anti-trypanosomatids activities

2020 ◽  
Vol 26 ◽  
Author(s):  
Luíza Dantas-Pereira ◽  
Edézio F. Cunha-Junior ◽  
Valter V. Andrade-Neto ◽  
John F. Bower ◽  
Guilherme A. M. Jardim ◽  
...  
Keyword(s):  
Large Scale ◽  
Neglected Tropical Diseases ◽  
Folk Medicine ◽  
Leishmania Species ◽  
Parasitic Infections ◽  
Mechanistic Analysis ◽  
Leishmania Spp ◽  
Nanomolar Range

: Chagas disease, Sleeping sickness and Leishmaniasis, caused by trypanosomatids Trypanosoma cruzi, Trypanosoma brucei and Leishmania spp., respectively, are considered neglected tropical diseases, and they especially affect impoverished populations in the developing world. The available chemotherapies are very limited and a search for alternatives is still necessary. In folk medicine, natural naphthoquinones have been employed for the treatment of a great variety of illnesses, including parasitic infections. This review is focused on the anti-trypanosomatid activity and mechanistic analysis of naphthoquinones and derivatives. Among all the series of derivatives tested in vitro, naphthoquinone-derived 1,2,3-triazoles were very active on T. cruzi infective forms in blood bank conditions, as well as in amastigotes of Leishmania spp. naphthoquinones containing a CF3 on a phenyl amine ring inhibited T. brucei proliferation in the nanomolar range, and naphthopterocarpanquinones stood out for their activity on a range of Leishmania species. Some of these compounds showed a promising selectivity index (SI) (30 to 1900), supporting further analysis in animal models. Indeed, high toxicity to the host and inactivation by blood components are crucial obstacles to be overcome to use naphthoquinones and/or their derivatives for chemotherapy. Multidisciplinary initiatives embracing medicinal chemistry, bioinformatics, biochemistry, and molecular and cellular biology need to be encouraged to allow the optimization of these compounds. Large scale automated tests are pivotal for the efficiency of the screening step, and subsequent evaluation of both the mechanism of action in vitro and pharmacokinetics in vivo are essential for the development of a novel, specific and safe derivative, minimizing adverse effects.

scholarly journals Therapeutic clinical trials to combat COVID-19 pandemic in India: analysis from trial registry

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Angelika Batta ◽  
Raj Khirasaria ◽  
Vinod Kapoor ◽  
Deepansh Varshney
Keyword(s):  
Clinical Trials ◽  
De Novo ◽  
Treatment Options ◽  
Drug Repurposing ◽  
Trial Registry ◽  
Therapeutic Treatment ◽  
Clinical Trial Registry ◽  
Clear Cut ◽  
Therapeutic Trials ◽  
Microsoft Office

AbstractObjectivesWith the emergence of Novel corona virus, hunt for finding a preventive and therapeutic treatment options has already begun at a rapid pace with faster clinical development programs. The present study was carried out to give an insight of therapeutic interventional trials registered under clinical trial registry of India (CTRI) for COVID-19 pandemic.MethodsAll trials registered under CTRI were evaluated using keyword “COVID” from its inception till 9th June 2020. Out of which, therapeutic interventional studies were chosen for further analysis. Following information was collected for each trial: type of therapeutic intervention (preventive/therapeutic), treatment given, no. of centers (single center/multicentric), type of institution (government/private), study design (randomized/single-blinded/double-blinded) and sponsors (Government/private). Microsoft Office Excel 2007 was used for tabulation and analysis.ResultsThe search yielded total of 205 trials, out of which, 127 (62%) trials were interventional trials. Out of these, 71 (56%) were AYUSH interventions, 36 (28.3%) tested drugs, 9 (7%) tested a nondrug intervention, rest were nutraceuticals and vaccines. About 66 (56%) were therapeutic trials. Majority were single-centered trials, i.e. 87 (73.7%). Trials were government funded in 57 (48.3%) studies. Majority were randomized controlled trials, i.e. 67 (56.8%). AYUSH preparations included AYUSH-64, Arsenic Album, SamshamaniVati etc.ConclusionsThe number of therapeutic interventional clinical trials was fair in India. A clear-cut need exists for an increase in both quantity and quality of clinical trials for COVID-19. Drug repurposing approach in all systems of medicine can facilitate prompt clinical decisions at lower costs than de novo drug development.

scholarly journals 4E Interacting Protein as a Potential Novel Drug Target for Nucleoside Analogues in Trypanosoma Brucei

2021 ◽  
Vol 9 (4) ◽  
pp. 826
Author(s):  
Dorien Mabille ◽  
Camila Cardoso Santos ◽  
Rik Hendrickx ◽  
Mathieu Claes ◽  
Peter Takac ◽  
...  
Keyword(s):  
Mode Of Action ◽  
Drug Target ◽  
Drug Targets ◽  
De Novo ◽  
Treatment Options ◽  
Adenosine Kinase ◽  
Nucleoside Analogues ◽  
Purine Salvage ◽  
Interacting Protein ◽  
Novel Drug

Human African trypanosomiasis is a neglected parasitic disease for which the current treatment options are quite limited. Trypanosomes are not able to synthesize purines de novo and thus solely depend on purine salvage from the host environment. This characteristic makes players of the purine salvage pathway putative drug targets. The activity of known nucleoside analogues such as tubercidin and cordycepin led to the development of a series of C7-substituted nucleoside analogues. Here, we use RNA interference (RNAi) libraries to gain insight into the mode-of-action of these novel nucleoside analogues. Whole-genome RNAi screening revealed the involvement of adenosine kinase and 4E interacting protein into the mode-of-action of certain antitrypanosomal nucleoside analogues. Using RNAi lines and gene-deficient parasites, 4E interacting protein was found to be essential for parasite growth and infectivity in the vertebrate host. The essential nature of this gene product and involvement in the activity of certain nucleoside analogues indicates that it represents a potential novel drug target.

scholarly journals S. pseudintermedius and S. aureus lineages with transmission ability circulate as causative agents of infections in pets for years

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Laura Ruiz-Ripa ◽  
Carmen Simón ◽  
Sara Ceballos ◽  
Carmelo Ortega ◽  
Myriam Zarazaga ◽  
...  
Keyword(s):  
Treatment Options ◽  
Companion Animals ◽  
Clinical History ◽  
Multidrug Resistant ◽  
Hospital Environment ◽  
Antimicrobial Resistance Profile ◽  
Causative Agents ◽  
Veterinary Hospital ◽  
Coagulase Positive Staphylococci

Abstract Background Staphylococcus pseudintermedius (SP) and Staphylococcus aureus (SA) are common colonizers of companion animals, but they are also considered opportunistic pathogens, causing diseases of diverse severity. This study focused on the identification and characterization of 33 coagulase-positive staphylococci isolated from diseased pets (28 dogs and five cats) during 2009–2011 in a veterinary hospital in Spain in order to stablish the circulating lineages and their antimicrobial resistance profile. Results Twenty-eight isolates were identified as SP and five as SA. Nine methicillin-resistant (MR) isolates (27%) carrying the mecA gene were detected (eight MRSP and one MRSA). The 55% of SP and SA isolates were multidrug-resistant (MDR). MRSP strains were typed as ST71-agrIII-SCCmecII/III-(PFGE) A (n=5), ST68-agrIV-SCCmecV-B1/B2 (n=2), and ST258-agrII-SCCmecIV-C (n=1). SP isolates showed resistance to the following antimicrobials [percentage of resistant isolates/resistance genes]: penicillin [82/blaZ], oxacillin [29/mecA] erythromycin/clindamycin [43/erm(B)], aminoglycosides [18–46/aacA-aphD, aphA3, aadE], tetracycline [71/tet(M), tet(K)], ciprofloxacin [29], chloramphenicol [29/catpC221], and trimethoprim-sulfamethoxazole [50/dfrG, dfrK]. The dfrK gene was revealed as part of the radC-integrated Tn559 in two SP isolates. Virulence genes detected among SP isolates were as follow [percentage of isolates]: siet [100], se-int [100], lukS/F-I [100], seccanine [7], and expB [7]. The single MRSA-mecA detected was typed as t011-ST398/CC398-agrI-SCCmecV and was MDR. The methicillin-susceptible SA isolates were typed as t045-ST5/CC5 (n=2), t10576-ST1660 (n=1), and t005-ST22/CC22 (n=1); the t005-ST22 feline isolate was PVL-positive and the two t045-ST45 isolates were ascribed to Immune Evasion Cluster (IEC) type F. Moreover, the t10576-ST1660 isolate, of potential equine origin, harbored the lukPQ and scneq genes. According to animal clinical history and data records, several strains seem to have been acquired from different sources of the hospital environment, while some SA strains appeared to have a human origin. Conclusions The frequent detection of MR and MDR isolates among clinical SP and SA strains with noticeable virulence traits is of veterinary concern, implying limited treatment options available. This is the first description of MRSA-ST398 and MRSP-ST68 in pets in Spain, as well the first report of the dfrK-carrying Tn559 in SP. This evidences that current transmissible lineages with mobilizable resistomes have been circulating as causative agents of infections among pets for years.

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