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1.
J Med Chem ; 67(10): 8323-8345, 2024 May 23.
Article in English | MEDLINE | ID: mdl-38722757

ABSTRACT

Leishmaniasis is a neglected tropical disease that is estimated to afflict over 12 million people. Current drugs for leishmaniasis suffer from serious deficiencies, including toxicity, high cost, modest efficacy, primarily parenteral delivery, and emergence of widespread resistance. We have discovered and developed a natural product-inspired tambjamine chemotype, known to be effective against Plasmodium spp, as a novel class of antileishmanial agents. Herein, we report in vitro and in vivo antileishmanial activities, detailed structure-activity relationships, and metabolic/pharmacokinetic profiles of a large library of tambjamines. A number of tambjamines exhibited excellent potency against both Leishmania mexicana and Leishmania donovani parasites with good safety and metabolic profiles. Notably, tambjamine 110 offered excellent potency and provided partial protection to leishmania-infected mice at 40 and/or 60 mg/kg/10 days of oral treatment. This study presents the first account of antileishmanial activity in the tambjamine family and paves the way for the generation of new oral antileishmanial drugs.


Subject(s)
Antiprotozoal Agents , Leishmania donovani , Leishmania mexicana , Animals , Structure-Activity Relationship , Antiprotozoal Agents/pharmacology , Antiprotozoal Agents/chemistry , Antiprotozoal Agents/therapeutic use , Antiprotozoal Agents/chemical synthesis , Antiprotozoal Agents/pharmacokinetics , Mice , Leishmania donovani/drug effects , Leishmania mexicana/drug effects , Drug Discovery , Humans , Female , Leishmaniasis/drug therapy , Mice, Inbred BALB C
2.
Vet Rec ; 194(11): e4089, 2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38809570

ABSTRACT

BACKGROUND: This study examined the experiences of owners of dogs with leishmaniosis who treated their dogs with daily subcutaneous meglumine antimoniate injections. The owners' perceived ease of administering the injections, the occurrence of problems and the effects on the owners and on the dog‒owner bond were evaluated. METHODS: Dogs prescribed meglumine antimoniate as a treatment for leishmaniosis were identified using the database of the veterinary pharmacy of the Faculty of Veterinary Medicine, Utrecht University. An online questionnaire was sent to the owners of these dogs to evaluate the perceived ease of administering the injections, the occurrence of problems and the effects on the owner and the dog-owner bond. RESULTS: Responses were received from 64 dog owners. Most respondents (78%) reported that administering the injections was not difficult. Pain or the development of nodules at the injection site was reported in 50% and 40% of the dogs, respectively. Polyuria was reported in 44% of the dogs. Some owners reported that administering the injections had a negative impact on their psychological wellbeing (20%), and some would have liked more veterinary support (11%). LIMITATIONS: Some questions were answered by a limited number of people, and their responses may not be representative. CONCLUSION: Dog owners remain highly motivated to persevere with meglumine antimoniate treatment and are willing to administer the injections themselves. The availability of active support when needed during the therapy cycle may further improve their acceptance of and confidence in giving the injections.


Subject(s)
Antiprotozoal Agents , Dog Diseases , Leishmaniasis , Meglumine Antimoniate , Dogs , Animals , Meglumine Antimoniate/therapeutic use , Meglumine Antimoniate/administration & dosage , Dog Diseases/drug therapy , Leishmaniasis/veterinary , Leishmaniasis/drug therapy , Surveys and Questionnaires , Humans , Male , Antiprotozoal Agents/therapeutic use , Antiprotozoal Agents/administration & dosage , Female , Ownership , Meglumine/therapeutic use , Meglumine/administration & dosage , Organometallic Compounds/administration & dosage , Organometallic Compounds/therapeutic use , Injections, Subcutaneous/veterinary
3.
Molecules ; 29(10)2024 May 09.
Article in English | MEDLINE | ID: mdl-38792079

ABSTRACT

Infectious diseases caused by trypanosomatids, including African trypanosomiasis (sleeping sickness), Chagas disease, and different forms of leishmaniasis, are Neglected Tropical Diseases affecting millions of people worldwide, mainly in vulnerable territories of tropical and subtropical areas. In general, current treatments against these diseases are old-fashioned, showing adverse effects and loss of efficacy due to misuse or overuse, thus leading to the emergence of resistance. For these reasons, searching for new antitrypanosomatid drugs has become an urgent necessity, and different metabolic pathways have been studied as potential drug targets against these parasites. Considering that trypanosomatids possess a unique redox pathway based on the trypanothione molecule absent in the mammalian host, the key enzymes involved in trypanothione metabolism, trypanothione reductase and trypanothione synthetase, have been studied in detail as druggable targets. In this review, we summarize some of the recent findings on the molecules inhibiting these two essential enzymes for Trypanosoma and Leishmania viability.


Subject(s)
Amide Synthases , Glutathione , NADH, NADPH Oxidoreductases , Trypanosoma , NADH, NADPH Oxidoreductases/metabolism , NADH, NADPH Oxidoreductases/antagonists & inhibitors , Humans , Amide Synthases/metabolism , Amide Synthases/antagonists & inhibitors , Trypanosoma/drug effects , Trypanosoma/metabolism , Glutathione/metabolism , Glutathione/analogs & derivatives , Animals , Spermidine/analogs & derivatives , Spermidine/metabolism , Leishmania/drug effects , Leishmania/metabolism , Trypanocidal Agents/pharmacology , Trypanocidal Agents/therapeutic use , Leishmaniasis/drug therapy , Leishmaniasis/metabolism , Leishmaniasis/parasitology , Trypanosomatina/metabolism , Trypanosomatina/drug effects , Protozoan Proteins/metabolism , Protozoan Proteins/antagonists & inhibitors , Chagas Disease/drug therapy , Chagas Disease/parasitology , Chagas Disease/metabolism
4.
Phytomedicine ; 129: 155640, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38714091

ABSTRACT

BACKGROUND: The discovery of artemisinin, an endoperoxide, encouraged the scientific community to explore endoperoxides as potential anti-parasitic molecules. Although artemisinin derivatives are rapidly evolving as potent anti-malarials, their potential as anti-leishmanials is emerging gradually. The treatment of leishmaniasis, a group of neglected tropical diseases is handicapped by lack of effective vaccines, drug toxicities and drug resistance. The weak antioxidant defense mechanism of the Leishmania parasites due to lack of catalase and a selenium dependent glutathione peroxidase system makes them vulnerable to oxidative stress, and this has been successful exploited by endoperoxides. PURPOSE: The study aimed to review the available literature on the anti-leishmanial efficacy of natural endoperoxides with a view to achieve insights into their mode of actions. METHODS: We reviewed more around 110 research and review articles restricted to the English language, sourced from electronic bibliographic databases including PubMed, Google, Web of Science, Google scholar etc. RESULTS: Natural endoperoxides could potentially augment the anti-leishmanial drug library, with artemisinin and ascaridole emerging as potential anti-leishmanial agents. Due to higher reactivity of the cyclic peroxide moiety, and exploiting the compromised antioxidant defense of Leishmania, endoperoxides like artemisinin and ascaridole potentiate their leishmanicidal efficacy by creating a redox imbalance. Furthermore, these molecules minimally impair oxidative phosphorylation; instead inhibit glycolytic functions, culminating in depolarization of the mitochondrial membrane and depletion of ATP. Additionally, the carbon-centered free radicals generated from endoperoxides, participate in chain reactions that can generate even more reactive organic radicals that are toxic to macromolecules, including lipids, proteins and DNA, leading to cell cycle arrest and apoptosis of Leishmania parasites. However, the precise target(s) of the toxic free radicals remains open-ended. CONCLUSION: In this overview, the spectrum of natural endoperoxide molecules as major anti-leishmanials and their mechanism of action has been delineated. In view of the substantial evidence that natural endoperoxides (e.g., artemisinin, ascaridole) exert a noxious effect on different species of Leishmania, identification and characterization of other natural endoperoxides is a promising therapeutic option worthy of further pharmacological consideration.


Subject(s)
Antiprotozoal Agents , Artemisinins , Leishmania , Peroxides , Leishmania/drug effects , Peroxides/pharmacology , Peroxides/chemistry , Antiprotozoal Agents/pharmacology , Antiprotozoal Agents/chemistry , Artemisinins/pharmacology , Artemisinins/chemistry , Humans , Leishmaniasis/drug therapy , Oxidative Stress/drug effects , Animals , Antioxidants/pharmacology
5.
Biomolecules ; 14(4)2024 Mar 27.
Article in English | MEDLINE | ID: mdl-38672424

ABSTRACT

Originally developed as a chemotherapeutic agent, miltefosine (hexadecylphosphocholine) is an inhibitor of phosphatidylcholine synthesis with proven antiparasitic effects. It is the only oral drug approved for the treatment of Leishmaniasis and American Trypanosomiasis (Chagas disease). Although its precise mechanisms are not yet fully understood, miltefosine exhibits broad-spectrum anti-parasitic effects primarily by disrupting the intracellular Ca2+ homeostasis of the parasites while sparing the human hosts. In addition to its inhibitory effects on phosphatidylcholine synthesis and cytochrome c oxidase, miltefosine has been found to affect the unique giant mitochondria and the acidocalcisomes of parasites. Both of these crucial organelles are involved in Ca2+ regulation. Furthermore, miltefosine has the ability to activate a specific parasite Ca2+ channel that responds to sphingosine, which is different to its L-type VGCC human ortholog. Here, we aimed to provide an overview of recent advancements of the anti-parasitic mechanisms of miltefosine. We also explored its multiple molecular targets and investigated how its pleiotropic effects translate into a rational therapeutic approach for patients afflicted by Leishmaniasis and American Trypanosomiasis. Notably, miltefosine's therapeutic effect extends beyond its impact on the parasite to also positively affect the host's immune system. These findings enhance our understanding on its multi-targeted mechanism of action. Overall, this review sheds light on the intricate molecular actions of miltefosine, highlighting its potential as a promising therapeutic option against these debilitating parasitic diseases.


Subject(s)
Calcium , Chagas Disease , Homeostasis , Leishmaniasis , Phosphorylcholine , Phosphorylcholine/analogs & derivatives , Humans , Phosphorylcholine/pharmacology , Phosphorylcholine/therapeutic use , Chagas Disease/drug therapy , Chagas Disease/parasitology , Chagas Disease/metabolism , Calcium/metabolism , Leishmaniasis/drug therapy , Leishmaniasis/metabolism , Leishmaniasis/parasitology , Homeostasis/drug effects , Animals , Antiprotozoal Agents/pharmacology , Antiprotozoal Agents/therapeutic use , Mitochondria/metabolism , Mitochondria/drug effects , Leishmania/drug effects , Leishmania/metabolism , Trypanosoma cruzi/drug effects , Trypanosoma cruzi/metabolism
6.
ACS Infect Dis ; 10(5): 1520-1535, 2024 May 10.
Article in English | MEDLINE | ID: mdl-38669567

ABSTRACT

The term "zoonosis" denotes diseases transmissible among vertebrate animals and humans. These diseases constitute a significant public health challenge, comprising 61% of human pathogens and causing an estimated 2.7 million deaths annually. Zoonoses not only affect human health but also impact animal welfare and economic stability, particularly in low- and middle-income nations. Leishmaniasis and schistosomiasis are two important neglected tropical diseases with a high prevalence in tropical and subtropical areas, imposing significant burdens on affected regions. Schistosomiasis, particularly rampant in sub-Saharan Africa, lacks alternative treatments to praziquantel, prompting concerns regarding parasite resistance. Similarly, leishmaniasis poses challenges with unsatisfactory treatments, urging the development of novel therapeutic strategies. Effective prevention demands a One Health approach, integrating diverse disciplines to enhance diagnostics and develop safer drugs. Metalloenzymes, involved in parasite biology and critical in different biological pathways, emerged in the last few years as useful drug targets for the treatment of human diseases. Herein we have reviewed recent reports on the discovery of inhibitors of metalloenzymes associated with zoonotic diseases like histone deacetylases (HDACs), carbonic anhydrase (CA), arginase, and heme-dependent enzymes.


Subject(s)
Leishmania , Leishmaniasis , Schistosoma , Schistosomiasis , Zoonoses , Animals , Humans , Leishmaniasis/drug therapy , Leishmaniasis/parasitology , Schistosoma/drug effects , Schistosoma/enzymology , Zoonoses/drug therapy , Schistosomiasis/drug therapy , Leishmania/drug effects , Leishmania/enzymology , Carbonic Anhydrases/metabolism , Histone Deacetylases/metabolism , Enzyme Inhibitors/pharmacology
7.
Eur J Med Chem ; 271: 116396, 2024 May 05.
Article in English | MEDLINE | ID: mdl-38643671

ABSTRACT

Neglected tropical diseases (NTDs) comprise diverse infections with more incidence in tropical/sub-tropical areas. In spite of preventive and therapeutic achievements, NTDs are yet serious threats to the public health. Epidemiological reports of world health organization (WHO) indicate that more than 1.5 billion people are afflicted with at least one NTD type. Among NTDs, leishmaniasis, chagas disease (CD) and human African trypanosomiasis (HAT) result in substantial morbidity and death, particularly within impoverished countries. The statistical facts call for robust efforts to manage the NTDs. Currently, most of the anti-NTD drugs are engaged with drug resistance, lack of efficient vaccines, limited spectrum of pharmacological effect and adverse reactions. To circumvent the issue, numerous scientific efforts have been directed to the synthesis and pharmacological development of chemical compounds as anti-infectious agents. A survey of the anti-NTD agents reveals that the majority of them possess privileged nitrogen, sulfur and oxygen-based heterocyclic structures. In this review, recent achievements in anti-infective small molecules against parasitic NTDs are described, particularly from the SAR (Structure activity relationship) perspective. We also explore current advocating strategies to extend the scope of anti-NTD agents.


Subject(s)
Neglected Diseases , Neglected Diseases/drug therapy , Humans , Structure-Activity Relationship , Molecular Structure , Small Molecule Libraries/chemistry , Small Molecule Libraries/pharmacology , Animals , Chagas Disease/drug therapy , Leishmaniasis/drug therapy , Antiprotozoal Agents/pharmacology , Antiprotozoal Agents/chemistry , Antiprotozoal Agents/chemical synthesis , Parasitic Sensitivity Tests , Tropical Medicine
8.
Vet Parasitol Reg Stud Reports ; 49: 100988, 2024 04.
Article in English | MEDLINE | ID: mdl-38462297

ABSTRACT

The incidence of human Visceral Leishmaniasis (VL) has decreased in Brazil; however, the number of areas reporting human and canine cases has increased, with Leishmania infantum usually preceding human infection. This study aimed to analyze the profile of infectious diseases that are endemic for both human and canine VL, in dogs housed in a shelter located in the state of Rio Grande do Norte, Northeast Brazil. Data was obtained between November/2021 to April/2022. All dogs residing at the shelter (98 dogs) were examined and blood was collected for testing for L. infantum, Ehrlichia canis, and Babesia sp. Statistical analyses considered the clinical and laboratory findings. Of the 98 animals, approximately 43% were positive for L. infantum antibodies, 19% were positive for L. infantum kDNA, and 18% were L. infantum positive by culture. Greater levels of anti-leishmania antibodies were observed in dogs with symptoms suggestive of VL. The dogs tested positive for E. canis (19/98) and B. canis (18/98). Lutzomyia longipalpis was captured inside the shelter, representing 74.25% (n = 225) of whole sandflies in the dog shelter. Concomitant infection by L. infantum and E. canis increased the odds of death. Treatment of VL included the use of allopurinol (n = 48) and miltefosine (n = 8). Treated animals showed more signs of Leishmania infection. Tickborn parasites and Leishmania were prevalent in sheltered dogs in a VL-endemic area, which increases the odds of death and poses an additional challenge for caring for abandoned dogs and at the same time setting protocols to manage reservoirs of L. infantum.


Subject(s)
Babesia , Dog Diseases , Leishmania infantum , Leishmaniasis, Visceral , Leishmaniasis , Psychodidae , Humans , Animals , Dogs , Leishmaniasis, Visceral/parasitology , Leishmaniasis, Visceral/veterinary , Leishmaniasis/drug therapy , Leishmaniasis/veterinary , Leishmania infantum/genetics , Psychodidae/parasitology , Dog Diseases/epidemiology
9.
Antimicrob Agents Chemother ; 68(4): e0155923, 2024 Apr 03.
Article in English | MEDLINE | ID: mdl-38497616

ABSTRACT

Leishmaniasis remains one of the main public health problems worldwide, with special incidence in the poorest populations. Selenium and its derivatives can be potent therapeutic options against protozoan parasites. In this work, 17 aryl selenoates were synthesized and screened against three species of Leishmania (Leishmania major, Leishmania amazonensis, and Leishmania infantum). Initial screening in promastigotes showed L. infantum species was more sensitive to selenoderivatives than the others. The lead Se-(2-selenocyanatoethyl) thiophene-2-carboselenoate (16) showed a half-maximal effective concentration of 3.07 µM and a selectivity index > 32.57 against L. infantum promastigotes. It was also the most effective of all 17 compounds, decreasing the infection ratio by 90% in L. infantum-infected macrophages with amastigotes at 10 µM. This aryl selenoate did not produce a hemolytic effect on human red blood cells at the studied doses (10-100 µM). Furthermore, the gene expression of infected murine macrophages related to cell death, the cell cycle, and the selenoprotein synthesis pathway in amastigotes was altered, while no changes were observed in their murine homologs, supporting the specificity of Compound 16 against the parasite. Therefore, this work reveals the possible benefits of selenoate derivatives for the treatment of leishmaniasis.


Subject(s)
Antiprotozoal Agents , Leishmania infantum , Leishmania mexicana , Leishmaniasis , Animals , Mice , Humans , Leishmaniasis/drug therapy , Antiprotozoal Agents/pharmacology , Antiprotozoal Agents/therapeutic use , Gene Expression , Mice, Inbred BALB C
11.
Eur Arch Otorhinolaryngol ; 281(5): 2739-2742, 2024 May.
Article in English | MEDLINE | ID: mdl-38453713

ABSTRACT

PURPOSE: To investigate the clinical manifestations, management and outcomes of Leishmania lesions in the ear-nose-throat (ENT) region, and its relationship with tumor necrosis factor (TNF)-α blocking drugs. METHODS: Single-center retrospective observational study. Patients diagnosed with cutaneous and mucosal leishmaniasis in the otorhinolaryngologic area at a tertiary referral center over a period of 8 years. RESULTS: Three cases of Leishmania lesions in the ear and two in the nose were encountered at our institution. All patients were under treatment with TNF-α blocking drugs. Diagnosis was challenging, and it was important to have a clinical suspicion in order to use accurate detection techniques. All patients received systemic treatment and achieved a complete resolution of the lesions. CONCLUSIONS: With the increasing use of biologic treatments like TNF-α blockers, this type of infection will be increasingly frequent in endemic areas and also worldwide. It is important to include leishmaniasis in the differential diagnosis of inflammatory/infectious lesions in the ENT region.


Subject(s)
Leishmaniasis, Cutaneous , Leishmaniasis , Otolaryngology , Humans , Tumor Necrosis Factor-alpha , Leishmaniasis/diagnosis , Leishmaniasis/drug therapy , Skin , Retrospective Studies , Leishmaniasis, Cutaneous/therapy
12.
J Ethnopharmacol ; 328: 118028, 2024 Jun 28.
Article in English | MEDLINE | ID: mdl-38492792

ABSTRACT

ETHNOPHARMACOLOGICAL RELEVANCE: Species of Vismia (Hypericaceae), known in Brazil as "lacre", are commonly used in traditional Amazonian medicine for the treatment of skin lesions, including those caused by Leishmania infection. AIM OF THE STUDY: Hexane extracts from the leaves of Vismia cayennensis, V. gracilis, V. sandwithii and V. guianensis, as well as from the fruits of the latter, in addition to the anthraquinones vismiaquinone, physcion and chrysophanol isolated from these species were explored for their anti-promastigote and anti-amastigote activity on Leishmania amazonensis. MATERIALS AND METHODS: Extracts were prepared by static maceration with n-hexane. The compounds, isolated by chromatographic techniques, were identified by spectroscopic methods (1H and 13C NMR). Promastigotes of L.amazonensis were incubated with hexane extracts (1-50 µg/mL) or anthraquinones (1-50 µM) and the parasite survival analyzed. The action of compounds on reactive oxygen species (ROS) production, mitochondrial membrane potential, and membrane integrity of promastigotes were evaluated by flow cytometer, and the cytotoxicity on mammalian cells using MTT assay. Furthermore, the activity of compounds against amastigotes and nitric oxide production were also investigated. RESULTS: Vismiaquinone and physcion were obtained from the leaves of V. guianensis. Physcion, as well as chrysophanol, were isolated from V. sandwithii. Vismia cayennensis and V. gracilis also showed vismiaquinone, compound detected in lower quantity in the fruits of V. guianensis. All extracts were active against the parasite, corroborating the popular use. The greatest activity against promastigotes was achieved with V. guianensis extract (IC50 4.3 µg/mL), precisely the most used Vismia species for treating cutaneous leishmaniasis. Vismiaquinone and physcion exhibited relevant activity with IC50 12.6 and 2.6 µM, respectively. Moreover, all extracts and anthraquinones tested induced ROS production, mitochondrial dysfunction, membrane disruption and were able to kill intracellular amastigote forms, being worthy of further in vivo studies as potential antileishmanial drugs. CONCLUSIONS: The overall data achieved in the current investigation scientifically validate the traditional use of Vismia species, mainly V. guianensis, as an anti-Leishmania agent. Furthermore, the promising results presented here indicate species of Vismia as potentially useful resources of Brazilian flora for the discovery of therapeutic solutions for neglected diseases.


Subject(s)
Antiprotozoal Agents , Clusiaceae , Emodin/analogs & derivatives , Leishmaniasis, Cutaneous , Leishmaniasis , Plants, Medicinal , Animals , Mice , Hexanes , Reactive Oxygen Species , Anthraquinones/pharmacology , Anthraquinones/therapeutic use , Leishmaniasis, Cutaneous/drug therapy , Leishmaniasis/drug therapy , Mice, Inbred BALB C , Mammals
13.
Exp Parasitol ; 260: 108747, 2024 May.
Article in English | MEDLINE | ID: mdl-38518969

ABSTRACT

Leishmaniasis are neglected infectious diseases caused by kinetoplastid protozoan parasites from the genus Leishmania. These sicknesses are present mainly in tropical regions and almost 1 million new cases are reported each year. The absence of vaccines, as well as the high cost, toxicity or resistance to the current drugs determines the necessity of new treatments against these pathologies. In this review, several compounds with potentialities as new antileishmanial drugs are presented. The discussion is restricted to the preclinical level and molecules are organized according to their chemical nature, source and molecular targets. In this manner, we present antimicrobial peptides, flavonoids, withanolides, 8-aminoquinolines, compounds from Leish-Box, pyrazolopyrimidines, and inhibitors of tubulin polymerization/depolymerization, topoisomerase IB, proteases, pteridine reductase, N-myristoyltransferase, as well as enzymes involved in polyamine metabolism, response against oxidative stress, signaling pathways, and sterol biosynthesis. This work is a contribution to the general knowledge of these compounds as antileishmanial agents.


Subject(s)
Antiprotozoal Agents , Leishmania , Leishmaniasis , Leishmaniasis/drug therapy , Antiprotozoal Agents/pharmacology , Antiprotozoal Agents/therapeutic use , Antiprotozoal Agents/chemistry , Leishmania/drug effects , Animals , Humans , Drug Evaluation, Preclinical , Flavonoids/pharmacology , Flavonoids/chemistry , Flavonoids/therapeutic use
14.
Trends Parasitol ; 40(3): 211-213, 2024 03.
Article in English | MEDLINE | ID: mdl-38368155

ABSTRACT

The drug discovery pipeline for leishmaniasis and trypanosomiasis has been filling with novel chemical entities with known mechanisms of action. González et al. and Braillard et al. report a cytochrome bc1 complex inhibitor as another promising preclinical candidate for visceral leishmaniasis (VL) and, in combination with benznidazole, for chronic Chagas' disease (CCD).


Subject(s)
Chagas Disease , Leishmaniasis, Visceral , Leishmaniasis , Trypanosoma cruzi , Trypanosomiasis , Humans , Chagas Disease/drug therapy , Leishmaniasis/drug therapy , Leishmaniasis, Visceral/drug therapy
15.
Sci Rep ; 14(1): 3246, 2024 02 08.
Article in English | MEDLINE | ID: mdl-38332162

ABSTRACT

Leishmania donovani is the causal organism of leishmaniasis with critical health implications affecting about 12 million people around the globe. Due to less efficacy, adverse side effects, and resistance, the available therapeutic molecules fail to control leishmaniasis. The mitochondrial primase of Leishmania donovani (LdmtPRI1) is a vital cog in the DNA replication mechanism, as the enzyme initiates the replication of the mitochondrial genome of Leishmania donovani. Hence, we target this protein as a probable drug target against leishmaniasis. The de-novo approach enabled computational prediction of the three-dimensional structure of LdmtPRI1, and its active sites were identified. Ligands from commercially available drug compounds were selected and docked against LdmtPRI1. The compounds were chosen for pharmacokinetic study and molecular dynamics simulation based on their binding energies and protein interactions. The LdmtPRI1 gene was cloned, overexpressed, and purified, and a primase activity assay was performed. The selected compounds were verified experimentally by the parasite and primase inhibition assay. Capecitabine was observed to be effective against the promastigote form of Leishmania donovani, as well as inhibiting primase activity. This study's findings suggest capecitabine might be a potential anti-leishmanial drug candidate after adequate further studies.


Subject(s)
Antiprotozoal Agents , Leishmania donovani , Leishmaniasis, Visceral , Leishmaniasis , Humans , Leishmania donovani/genetics , DNA Primase , DNA, Mitochondrial , Capecitabine/therapeutic use , Drug Repositioning , Leishmaniasis/drug therapy , Leishmaniasis, Visceral/drug therapy , Leishmaniasis, Visceral/parasitology , Antiprotozoal Agents/chemistry
16.
Antimicrob Agents Chemother ; 68(3): e0112723, 2024 Mar 06.
Article in English | MEDLINE | ID: mdl-38349159

ABSTRACT

The problems associated with the drugs currently used to treat leishmaniasis, including resistance, toxicity, and the high cost of some formulations, call for the urgent identification of new therapeutic agents with novel modes of action. The aggregated protein dye YAT2150 has been found to be a potent antileishmanial compound, with a half-maximal inhibitory concentration (IC50) of approximately 0.5 µM against promastigote and amastigote stages of Leishmania infantum. The encapsulation in liposomes of YAT2150 significantly improved its in vitro IC50 to 0.37 and 0.19 µM in promastigotes and amastigotes, respectively, and increased the half-maximal cytotoxic concentration in human umbilical vein endothelial cells to >50 µM. YAT2150 became strongly fluorescent when binding intracellular protein deposits in Leishmania cells. This fluorescence pattern aligns with the proposed mode of action of this drug in the malaria parasite Plasmodium falciparum, the inhibition of protein aggregation. In Leishmania major, YAT2150 rapidly reduced ATP levels, suggesting an alternative antileishmanial mechanism. To the best of our knowledge, this first-in-class compound is the only one described so far having significant activity against both Plasmodium and Leishmania, thus being a potential drug for the treatment of co-infections of both parasites.


Subject(s)
Antiprotozoal Agents , Leishmania infantum , Leishmaniasis , Parasites , Animals , Humans , Endothelial Cells , Leishmaniasis/drug therapy , Antiprotozoal Agents/pharmacology , Antiprotozoal Agents/therapeutic use
17.
Acta Trop ; 252: 107143, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38331084

ABSTRACT

Leishmaniasis is an endemic disease in more than 90 countries, constituting a relevant public health problem. Limited treatment options, increase in resistance, and therapeutic failure are important aspects for the discovery of new treatment options. Drug repurposing may accelerate the discovery of antiLeishmanial drugs. Recent tests indicating the in vitro potential of antimalarials Leishmania resulted in the design of this study. This study aimed at evaluating the susceptibility of Leishmania (L.) amazonensis to chloroquine (CQ) and quinine (QN), alone or in combination with amphotericin B (AFT) and pentamidine (PTN). In the in vitro tests, first, we evaluated the growth inhibition of 50 % of promastigotes (IC50) and cytotoxicity for HepG2 and THP-1 cells (CC50). The IC50 values of AFT and PNT were below 1 µM, while the IC50 values of CQ and QN ranged between 4 and 13 µM. Concerning cytotoxicity, CC50 values ranged between 7 and 30 µM for AFT and PNT, and between 22 and 157 µM for the antimalarials. We also calculated the Selectivity Index (SI), where AFT and PTN obtained the highest values, while the antimalarias obtained values between 5 and 12. Both antimalarials were additive (Æ©FIC 1.05-1.8) in combination with AFT and PTN. For anti-amastigote activity, the drugs obtained the following ICA50 values: AFT (0.26 µM), PNT (2.09 µM), CQ (3.77 µM) and QN (24.5 µM). In the in vivo tests, we observed that the effective dose for the death of 50 % of parasites (ED50) of AFT and CQ were 0.63 mg/kg and 27.29 mg/kg, respectively. When combining CQ with AFT, a decrease in parasitemia was observed, being statistically equal to the naive group. For cytokine quantification, it was observed that CQ, despite presenting anti-inflammatory activity was effective at increasing the production of IFN-γ. Overall, our data indicate that chloroquine will probably be a candidate for repurposing and use in drug combination therapy.


Subject(s)
Antimalarials , Leishmania , Leishmaniasis , Humans , Chloroquine/pharmacology , Chloroquine/therapeutic use , Quinine/pharmacology , Quinine/therapeutic use , Antimalarials/pharmacology , Antimalarials/therapeutic use , Leishmaniasis/drug therapy , Plasmodium falciparum
18.
Biomed Pharmacother ; 172: 116254, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38340398

ABSTRACT

Leishmaniases, a group of diseases caused by the species of the protozoan parasite Leishmania, remains a significant public health concern worldwide. Host immune responses play a crucial role in the outcome of Leishmania infections, and several mediators that regulate inflammatory responses are potential targets for therapeutic approaches. Annexin A1 (AnxA1), an endogenous protein endowed with anti-inflammatory and pro-resolving properties, has emerged as a potential player. We have shown that during L. braziliensis infection, deficiency of AnxA1 exacerbates inflammatory responses but does not affect parasite burden. Here, we have investigated the role of AnxA1 in L. amazonensis infection, given the non-healing and progressive lesions characteristic of this infectious model. Infection of AnxA1 KO BALB/c mice resulted in increased lesion size and tissue damage associated with higher parasite burdens and enhanced inflammatory response. Notably, therapeutic application of the AnxA1 peptidomimetic Ac2-26 improves control of parasite replication and increases IL-10 production in vivo and in vitro, in both WT and AnxA1 KO mice. Conversely, administration of WRW4, an inhibitor of FPR2/3, resulted in larger lesions and decreased production of IL-10, suggesting that the effects of AnxA1 during L. amazonensis infection are associated with the engagement of these receptors. Our study illuminates the role of AnxA1 in L. amazonensis infection, demonstrating its impact on the susceptibility phenotype of BALB/c mice. Furthermore, our results indicate that targeting the AnxA1 pathway by using the Ac2-26 peptide could represent a promising alternative for new treatments for leishmaniasis.


Subject(s)
Annexin A1 , Leishmania , Leishmaniasis , Peptides , Animals , Mice , Annexin A1/administration & dosage , Annexin A1/metabolism , Immunity , Interleukin-10/metabolism , Leishmaniasis/drug therapy , Mice, Inbred BALB C , Peptides/administration & dosage
19.
Article in English | MEDLINE | ID: mdl-38279725

ABSTRACT

AIMS: Leishmaniasis is a deadly tropical disease that is neglected in many countries. World Health Organization, along with a few other countries, has been working together to protect against these parasites. Many novel drugs from the past few years have been discovered and subjected against leishmaniasis, which have been effective but they are quite expensive for lower-class people. Some drugs showed no effect on the patients, and the longer use of these medicines has made resistance against these deadly parasites. Researchers have been working for better medication by using natural products from medicinal plants (oils, secondary metabolites, plant extracts) and other alternatives to find active compounds as an alternative to the current synthetic drugs. MATERIALS AND METHODS: To find more potential natural products to treat Leishmania spp, a study has been conducted and reported many plant metabolites and other natural alternatives from plants and their extracts. Selected research papers with few term words such as natural products, plant metabolites, Leishmaniasis, in vivo, in vitro, and treatment against leishmaniasis; in the Google Scholar, PubMed, and Science Direct databases with selected research papers published between 2015 and 2021 have been chosen for further analysis has been included in this report which has examined either in vivo or in vitro analysis. RESULTS: This paper reported more than 20 novel natural compounds in 20 research papers that have been identified which report a leishmanicidal activity and shows an action against promastigote, axenic, and intracellular amastigote forms. CONCLUSION: Medicinal plants, along with a few plant parts and extracts, have been reported as a possible novel anti-leishmanial medication. These medicinal plants are considered nontoxic to Host cells. Leishmaniasis treatments will draw on the isolated compounds as a source further and these compounds compete with those already offered in clinics.


Subject(s)
Antiprotozoal Agents , Biological Products , Leishmania , Leishmaniasis , Plants, Medicinal , Humans , Biological Products/pharmacology , Biological Products/therapeutic use , Antiprotozoal Agents/pharmacology , Antiprotozoal Agents/therapeutic use , Leishmaniasis/drug therapy , Animals , Plants, Medicinal/chemistry , Leishmania/drug effects , Plant Extracts/pharmacology , Plant Extracts/therapeutic use
20.
Parasitol Int ; 100: 102863, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38272301

ABSTRACT

Leishmania, a protozoan parasite, is responsible for the occurrence of leishmaniasis, a disease that is prevalent in tropical regions. Visceral Leishmaniasis (VL), also known as kala-azar in Asian countries, is one of the most significant forms of VL, along with Cutaneous Leishmaniasis (CL) and Mucocutaneous Leishmaniasis (ML). Management of this condition typically entails the use of chemotherapy as the sole therapeutic option. The current treatments for leishmaniasis present several drawbacks, including a multitude of side effects, prolonged treatment duration, disparate efficacy across different regions, and the emergence of resistance. To address this urgent need, it is imperative to identify alternative treatments that are both safer and more effective. The identification of appropriate pharmacological targets in conjunction with biological pathways constitutes the initial stage of drug discovery. In this review, we have addressed the key metabolic pathways that represent potential pharmacological targets as well as prominent treatment options for leishmaniasis.


Subject(s)
Leishmania donovani , Leishmania , Leishmaniasis, Cutaneous , Leishmaniasis, Mucocutaneous , Leishmaniasis, Visceral , Leishmaniasis , Animals , Leishmaniasis/drug therapy , Leishmaniasis, Visceral/drug therapy , Leishmaniasis, Visceral/parasitology , Asia
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