ABSTRACT
Amoebas of the genus Acanthamoeba are distributed worldwide, including species with a high pathogenic capacity for humans. In a similar way to what occurs with other parasitic protozoa, the available treatments show variable effectiveness in addition to high toxicity, which demands the development of new treatments. Positive results of 5-nitroindazole derivatives against several protozoa parasites suggest that these compounds may be a promising tool for the development of efficient antiparasitic drugs. In the present work we have evaluated the in vitro activity of ten 5-nitroindazole derivatives against Acanthamoeba castellanii trophozoites and cysts. To that end, AlamarBlue Assay Reagent® was used to determine the activity against trophozoites compared to the reference drug chlorhexidine digluconate. Cytotoxicity of the compounds was evaluated using Vero cells. The activity on cysts was evaluated by light microscopy and using a Neubauer chamber to quantifying cysts and presence of trophozoites, as an indication of cyst. Our results showed the effectiveness of the 5-nitroindazole derivatives tested against both trophozoites and cysts of A. castellani highlighting 5-nitroindazole derivative 8 which showed a 80% activity on cysts, which is higher than that of the reference drug. Moreover, 5-nitroindazole derivatives 8, 9 and 10 were more effective on trophozoites than the reference drug showing IC50 values lower than 5 µM. Taking together these results, these 5-nitroindazole derivatives specially compound 8, might be a promising alternative for the development of more efficient treatments against A. castellani infection.
Subject(s)
Acanthamoeba castellanii , Animals , Chlorocebus aethiops , Humans , Indazoles/pharmacology , Trophozoites , Vero CellsABSTRACT
BACKGROUND: The World Health Organization catalogues illnesses such as Chagas disease as neglected diseases, due to the low investment in new drugs to fight them. The search for novel and non-side effects anti-parasitic compounds is one of the urgent needs of the Third World. The use of triazolopyrimidines and their metal complexes have demonstrated hopeful results in this field. OBJECTIVE: This work studies the antiparasitic efficacy against Trypanosoma cruzi strains of a series of zinc triazolopyrimidine complexes. METHODS: A series of Zn complexes has been synthesized by the reaction between the triazolopyrimidine derivatives 7-amino-1,2,4-triazolo[1,5-a]pyrimidine (7atp) and 5,7-dimethyl-1,2,4-triazolo[1,5- a]pyrimidine (dmtp) with Zn(SO4) · 7H2O, ZnCl2, and Zn(NO3)2 · 6H2O salts. The complexes have been analyzed by spectroscopic and thermal assays and X-ray diffraction methods have been used to dilucidate the crystalline structure of one of them. The antiparasitic efficacy was tested in vitro against Trypanosoma cruzi to compare the trypanocidal effect of different ligands and counteranions to fight Chagas disease. RESULTS: The efficacy of these compounds against Trypanosoma cruzi has also been tested to compare the influence of different ligands and counteranions on the trypanocidal effect against Chagas disease. CONCLUSION: Antiproliferative tests corroborate the synergistic trypanocidal effect of the triazolopyrimidine coordination complexes.
Subject(s)
Chagas Disease , Coordination Complexes , Trypanocidal Agents , Trypanosoma cruzi , Chagas Disease/drug therapy , Coordination Complexes/chemistry , Coordination Complexes/pharmacology , Humans , Pyrimidines/chemistry , Trypanocidal Agents/pharmacology , Zinc/chemistry , Zinc/pharmacologyABSTRACT
Leishmaniasis is one of the world's most neglected diseases with a worldwide prevalence of 12 million people. There are no effective human vaccines for its prevention, and outdated drugs hamper treatment. Therefore, research aimed at developing new therapeutic tools to fight leishmaniasis remains a crucial goal today. With this purpose in mind, here, we present 10 new compounds made up by linking alkylated ethylenediamine units to pyridine or quinoline heterocycles with promising in vitro and in vivo efficacy against promastigote and amastigote forms of Leishmania infantum, Leishmania donovani, and Leishmania braziliensis species. Three compounds (2, 4, and 5) showed a selectivity index much higher in the amastigote form than the reference drug glucantime. These three derivatives affected the parasite infectivity rates; the result was lower parasite infectivity rates than glucantime tested at an IC25 dose. In addition, these derivatives were substantially more active against the three Leishmania species tested than glucantime. The mechanism of action of these compounds has been studied, showing alterations in glucose catabolism and leading to greater levels of iron superoxide dismutase inhibition. These molecules could be potential candidates for leishmaniasis chemotherapy due to their effectiveness and their ready synthesis.
Subject(s)
Antiprotozoal Agents , Leishmania braziliensis , Leishmania infantum , Leishmaniasis , Antiprotozoal Agents/pharmacology , Diamines/pharmacology , Humans , Leishmaniasis/drug therapyABSTRACT
Leishmaniasis and Chagas diseases are two of the most important parasitic diseases in the world. Both belong to the category of Neglected Tropical Diseases, and they cannot be prevented by vaccination. Their treatments are founded in outdated drugs that possess many pernicious side-effects and they're not easy to administer. With the aim of discovering new compounds that could serve as anti-trypanosomal drugs, an antiparasitic study of a synthetic compound family has been conducted. A series of new 1,4-bis(alkylamino)- and 1-alkylamino-4-chloroazine and benzoazine derivatives 1-4 containing imidazole rings have been synthesized and identified. Their structures showed a possible interest based on previous work. Their inâ vitro anti-Leishmania infantum, anti-L.â braziliensis, anti-L.â donovani and anti-T.â cruzi activity were tested, as well as the inhibition of Fe-SOD enzymes. It was found that some of them exhibited quite relevant values indicative of being worthy of future more detailed studies, as most of them showed activity to more than only one parasite species, especially compound 3 c was active for the three studied Leishmania species and also for T.â cruzi, which is a very interesting trait as it covers a wide spectrum.
Subject(s)
Imidazoles/pharmacology , Phthalazines/pharmacology , Pyridazines/pharmacology , Trypanocidal Agents/pharmacology , Animals , Chlorocebus aethiops , Imidazoles/chemical synthesis , Imidazoles/toxicity , Leishmania braziliensis/drug effects , Leishmania donovani/drug effects , Leishmania infantum/drug effects , Parasitic Sensitivity Tests , Phthalazines/chemical synthesis , Phthalazines/toxicity , Pyridazines/chemical synthesis , Pyridazines/toxicity , Trypanocidal Agents/chemical synthesis , Trypanocidal Agents/toxicity , Trypanosoma cruzi/drug effects , Vero CellsABSTRACT
Chagas disease is usually caused by tropical infection with the insect-transmitted protozoan Trypanosoma cruzi. Currently, Chagas disease is a major public health concern worldwide due to globalization, and there are no treatments neither vaccines because of the long-term nature of the disease and its complex pathology. Current treatments are limited to two obsolete drugs, benznidazole and nifurtimox, which lead to serious drawbacks. Taking into account the urgent need for strict research efforts to find new therapies, here, we describe the in vitro and in vivo trypanocidal activity of a library of selected forty-eight selenocyanate and diselenide derivatives that exhibited leishmanicidal properties. The inclusion of selenium, an essential trace element, was due to the well-known extensive pharmacological activities for selenium compounds including parasitic diseases as T. cruzi. Here we present compound 8 as a potential compound that exhibits a better profile than benznidazole both in vitro and in vivo. It shows a fast-acting behaviour that could be attributed to its mode of action: it acts in a mitochondrion-dependent manner, causing cell death by bioenergetic collapse. This finding provides a step forward for the development of a new antichagasic agent.
ABSTRACT
Acanthamoeba spp. are widely distributed in the environment and cause serious infections in humans. Treatment of Acanthamoeba infections is very challenging and not always effective which requires the development of more efficient drugs against Acanthamoeba spp. The purpose of the present study was to test medicinal plants that may be useful in the treatment of Acanthamoeba spp. Here we evaluated the trophozoital and cysticidal activity of 13 flavonoid glycosides isolated from Delphinium gracile, D. staphisagria, Consolida oliveriana and from Aconitum napellus subsp. Lusitanicum against the amoeba Acanthamoeba castellanii. AlamarBlue Assay Reagent® was used to determine the activity against trophozoites of A. castellanii, and cytotoxic using Vero cells. Cysticidal activity was assessed on treated cysts by light microscopy using a Neubauer chamber to quantify cysts and trophozoites. Flavonoids 1, 2, 3 and 4 showed higher trophozoital activity and selectivity indexes than the reference drug chlorhexidine digluconate. In addition, flavonoid 2 showed 100% cysticidal activity at a concentration of 50 µm, lower than those of the reference drug and flavonoid 3 (100 µm). These results suggest that flavonoids 2 and 3 might be used for the development of novel therapeutic approaches against Acanthamoeba infections after satisfactory in vivo evaluations.
Subject(s)
Acanthamoeba/drug effects , Aconitum/chemistry , Delphinium/chemistry , Glycosides/pharmacology , Plant Extracts/pharmacology , Ranunculaceae/chemistry , Acanthamoeba/growth & development , Animals , Chlorocebus aethiops , Flavonoids/chemistry , Flavonoids/isolation & purification , Flavonoids/pharmacology , Flavonoids/toxicity , Glycosides/chemistry , Glycosides/isolation & purification , Glycosides/toxicity , Inhibitory Concentration 50 , Molecular Structure , Plant Extracts/isolation & purification , Trophozoites/drug effects , Trophozoites/growth & development , Vero Cells/drug effectsABSTRACT
Chagas disease is a tropical infection caused by the protozoan parasite Trypanosoma cruzi and a global public health concern. It is a paradigmatic example of a chronic disease without an effective treatment. Current treatments targeting T. cruzi are limited to two obsolete nitroheterocyclic drugs, benznidazole and nifurtimox, which lead to serious drawbacks. Hence, new, more effective, safer, and affordable drugs are urgently needed. Selenium and their derivatives have emerged as an interesting strategy for the treatment of different prozotoan diseases, such as African trypanosomiasis, leishmaniasis, and malaria. In the case of Chagas disease, diverse selenium scaffolds have been reported with antichagasic activity in vitro and in vivo. On the basis of these premises, we describe the in vitro and in vivo trypanocidal activity of 41 selenocompounds against the three morphological forms of different T. cruzi strains. For the most active selenocompounds, their effect on the metabolic and mitochondrial levels and superoxide dismutase enzyme inhibition capacity were measured in order to determine the possible mechanism of action. Derivative 26, with a selenocyanate motif, fulfills the most stringent in vitro requirements for potential antichagasic agents and exhibits a better profile than benznidazole in vivo. This finding provides a step forward for the development of a new antichagasic agent.
Subject(s)
Chagas Disease , Pharmaceutical Preparations , Selenium , Trypanocidal Agents , Trypanosoma cruzi , Chagas Disease/drug therapy , Humans , Selenium/therapeutic use , Trypanocidal Agents/pharmacologyABSTRACT
The life-long and life-threatening Chagas disease is one of the most neglected tropical diseases caused by the protozoan parasite Trypanosoma cruzi. It is a major public health problem in Latin America, as six to seven million people are infected, being the principal cause of mortality in many endemic regions. Moreover, Chagas disease has become widespread due to migrant populations. Additionally, there are no vaccines nor effective treatments to fight the disease because of its long-term nature and complex pathology. Therefore, these facts emphasize how crucial the international effort for the development of new treatments against Chagas disease is. Here, we present the in vitro and in vivo trypanocidal activity of some oxygenated abietane diterpenoids and related compounds. The 1,4-benzoquinone 15, not yet reported, was identified as a fast-acting trypanocidal drug with efficacy against different strains in vitro and higher activity and lower toxicity than benznidazole in both phases of murine Chagas disease. The mode of action was also evaluated, suggesting that quinone 15 kills T. cruzi by inducing mitochondrion-dependent necrosis through a bioenergetics collapse caused by a mitochondrial membrane depolarization and iron-containing superoxide dismutase inhibition. Therefore, the abietane 1,4-benzoquinone 15 can be considered as a new candidate molecule for the development of an appropriate and commercially accessible anti-Chagas drug.
Subject(s)
Abietanes/pharmacology , Mitochondria/metabolism , Trypanocidal Agents/pharmacology , Abietanes/chemistry , Animals , Humans , Mice , NecrosisABSTRACT
We report on the formation of a triazolopyrimidine derivative ligand, 7-amino-5-methyl-1,2,4-triazolo[1,5-a]pyrimidine (7-amtp), and a new family of coordination compounds based on this ligand and zinc as metal ion, synthesized by conventional routes. These materials possess different mononuclear structures, namely [ZnCl2(7-amtp)2] (1), [Zn(7-amtp)2(H2O)4](NO3)2·2(7-amtp)·6H2O (2) and [Zn(7-amtp)2(H2O)4](SO4)·1.5H2O (3) derived from the use of different zinc (II) salts, in such a way that the counterions govern the crystallization to a large extent. These compounds present and show variable luminescent properties based on ligand-centred charge transfers which have been deeply studied by Time Dependent Density Functional Theory (TD-DFT) calculations. When these compounds are transferred to solution, preserving complex entities as corroborated by NMR studies, they present interesting anti-diabetic and anti-parasitic capabilities, with a comparatively higher selectivity index than other previously reported triazolopyrimidine-based materials. The results derived from in vivo experiments conducted in mice also confirm their promising activity as anti-diabetic drug being capable of dropping glucose levels after oral administration. Therefore, these new materials may be considered as excellent candidates to be further investigated in the field of luminescent coordination compounds with biomedical applications.
Subject(s)
Antiparasitic Agents/pharmacology , Coordination Complexes/pharmacology , Hypoglycemic Agents/pharmacology , Pyrimidines/chemistry , Zinc/chemistry , LigandsABSTRACT
Trypanosomatidae is a family of unicellular parasites belonging to the phylum Euglenozoa, which are causative agents in high impact human diseases such as Leishmaniasis, Chagas disease and African sleeping sickness. The impact on human health and local economies, together with a lack of satisfactory chemotherapeutic treatments and effective vaccines, justifies stringent research efforts to search for new disease therapies. Here, we present in vitro trypanocidal activity data and mode of action data, repositioning leishmanicidal [1,2,3]Triazolo[1,5-a]pyridinium salts against Trypanosoma cruzi, the aetiological agent of Chagas disease. This disease is one of the most neglected tropical diseases and is a major public health issue in Central and South America. The disease affects approximately 6-7 million people and is widespread due to increased migratory movements. We screened a suite of leishmanicidal [1,2,3]Triazolo[1,5-a]pyridinium salt compounds, of which compounds 13, 20 and 21 were identified as trypanocidal drugs. These compounds caused cell death in a mitochondrion-dependent manner through a bioenergetic collapse. Moreover, compounds 13 and 20 showed a remarkable inhibition of iron superoxide dismutase activity of T. cruzi, a key enzyme in the protection from the damage produced by oxidative stress.
Subject(s)
Chagas Disease/drug therapy , Pyridinium Compounds/pharmacology , Trypanocidal Agents/pharmacology , Trypanosoma cruzi/drug effects , Animals , Cell Death/drug effects , Drug Repositioning , Humans , Leishmaniasis/drug therapy , Mitochondrial Membranes/metabolism , Oxidative Stress/drug effects , South America , Superoxide Dismutase/metabolism , Trypanosomiasis, African/drug therapyABSTRACT
OBJECTIVES: We report the in vivo trypanocidal activity of the bacteriocin AS-48 (lacking toxicity), which is produced by Enterococcus faecalis, against the flagellated protozoan Trypanosoma cruzi, the aetiological agent of Chagas' disease. METHODS: We determined the in vivo activity of AS-48 against the T. cruzi Arequipa strain in BALB/c mice (in both acute and chronic phases of Chagas' disease). We evaluated the parasitaemia, the reactivation of parasitaemia after immunosuppression and the nested parasites in the chronic phase by PCR in target tissues. RESULTS: AS-48 reduced the parasitaemia profile in acute infection and showed a noteworthy reduction in the parasitic load in chronic infection after immunosuppression according to the results obtained by PCR (double-checking to demonstrate cure). CONCLUSIONS: AS-48 is a promising alternative that provides a step forward in the development of a new therapy against Chagas' disease.
Subject(s)
Chagas Disease , Trypanosoma cruzi , Animals , Chagas Disease/drug therapy , Mice , Mice, Inbred BALB C , Parasite Load , Parasitemia/drug therapyABSTRACT
BACKGROUND: The World Health Organization catalogues illnesses such as Leishmaniasis as neglected diseases, due to low investment in new drugs to fight them. The search of novel and non-side effects anti-parasitic compounds is one of the urgent needs for the Third World. The use of triazolopyrimidines and their metallic complexes has demonstrated hopeful results in this field. OBJECTIVE: This work studies the antiparasitic efficacy of a series of 5,7-dimethyl-1,2,4- triazolo[1,5-a]pyrimidine first row transition metal complexes against three leishmania spp. strains. METHODS: The in vitro antiproliferation of promastigote forms of different strains of leishmania spp. (L. infantum, L. braziliensis and L donovani) and the cytotoxicity in macrophage host cells are reported here. The antiparasitic assays have been complemented with enzymatic tests to elucidate the mechanisms of action. New crystal structure description, thermal analysis, magnetic susceptibility and magnetization experiments have also been carried out in order to present a whole characterization of the studied compounds and interesting physical properties besides the biological tests. RESULTS: The results of antiproliferation screening and cytotoxicity show great antiparasitic efficacy in the studied complexes. The superoxide dismutase enzymatic assays exhibit a different behaviour according to the thermochromic triazolopyrimidine form tested. CONCLUSION: Antiproliferative assays and enzymatic tests corroborate the synergetic leishmanicidal effect present in coordination triazolopyrimidine complexes. The changes in coordination sphere derived from thermochromism affect the physical properties as well as the biological efficacy.
Subject(s)
Coordination Complexes/pharmacology , Pyrimidines/pharmacology , Triazoles/pharmacology , Trypanocidal Agents/pharmacology , Animals , Cell Line , Color , Coordination Complexes/chemical synthesis , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/pharmacology , Leishmania braziliensis/drug effects , Leishmania donovani/drug effects , Leishmania infantum/drug effects , Mice , Parasitic Sensitivity Tests , Pyrimidines/chemical synthesis , Superoxide Dismutase/metabolism , Temperature , Triazoles/chemical synthesis , Trypanocidal Agents/chemical synthesisABSTRACT
Two dinuclear silver complexes containing 5,7-dimethyl[1,2,4]triazolo[1,5-a]pyrimidine (dmtp) were synthesized, [Ag2(dmtp)3]2[Ag2(dmtp)2](BF4)6(H2O)2 and [Ag2(dmtp)2(ClO4)2][Ag2(dmtp)2(H2O)2](ClO4)2. They have been spectroscopically and thermally characterized and their structures have been solved by single crystal X-ray diffraction. The compounds display fluorescence in the visible range (486â¯nm) when irradiated with UV light (265â¯nm). Both compounds, together with a previously reported analogue containing nitrate as counteranion, were assayed in vitro against three different species of Leishmania spp. and Trypanosoma cruzi, (parasites responsible for Leishmaniasis and Chagas disease) showing an extremely high antiparasitic activity, with IC50 values below the lower tested concentration (1⯵M) for the three compounds and the four microorganisms, and hence a selectivity index better than those of the reference commercial drugs by more than one magnitude order, also improving the results of the free ligand and previously reported complexes with metals of the first transition series.
Subject(s)
Antiprotozoal Agents/chemical synthesis , Organometallic Compounds/chemical synthesis , Silver/chemistry , Antiprotozoal Agents/pharmacology , Fluorescence , Leishmania/drug effects , Organometallic Compounds/pharmacology , Pyrimidines/chemistry , Triazoles/chemistry , Trypanosoma cruzi/drug effectsABSTRACT
Leishmaniasis is a widespread neglected tropical disease complex that is responsible of one million new cases per year. Current treatments are outdated and pose many problems that new drugs need to overcome. With the goal of developing new, safe, and affordable drugs, we have studied the in vitro activity of 12 different 5-nitroindazole derivatives that showed previous activity against different strains of Trypanosoma cruzi in a previous work. T. cruzi belongs to the same family as Leishmania spp., and treatments for the disease it produces also needs renewal. Among the derivatives tested, compounds 1, 2, 9, 10, 11, and 12 showed low J774.2 macrophage toxicity, while their effect against both intracellular and extracellular forms of the studied parasites was higher than the ones found for the reference drug Meglumine Antimoniate (Glucantime®). In addition, their Fe-SOD inhibitory effect, the infection rates, metabolite alteration, and mitochondrial membrane potential of the parasites treated with the selected drugs were studied in order to gain insights into the action mechanism, and the results of these tests were more promising than those found with glucantime, as the leishmanicidal effect of these new drug candidates was higher. The promising results are encouraging to test these derivatives in more complex studies, such as in vivo studies and other experiments that could find out the exact mechanism of action.
Subject(s)
Alcohols/pharmacology , Antiprotozoal Agents/pharmacology , Enzyme Inhibitors/pharmacology , Ethylamines/pharmacology , Indazoles/pharmacology , Leishmania/drug effects , Alcohols/chemistry , Alcohols/metabolism , Animals , Antiprotozoal Agents/chemistry , Antiprotozoal Agents/metabolism , Cell Line , Dose-Response Relationship, Drug , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/metabolism , Ethylamines/chemistry , Ethylamines/metabolism , Indazoles/chemistry , Indazoles/metabolism , Macrophages/drug effects , Macrophages/parasitology , Membrane Potential, Mitochondrial/drug effects , Mice , Molecular Structure , Parasitic Sensitivity Tests , Structure-Activity Relationship , Superoxide Dismutase/antagonists & inhibitors , Superoxide Dismutase/metabolismABSTRACT
The in vitro antimicrobial potency of the bacteriocin AS-48 is well documented, but its clinical application requires investigation, as its toxicity could be different in in vitro (haemolytic and antibacterial activity in blood and cytotoxicity towards normal human cell lines) and in vivo (e.g. mice and zebrafish embryos) models. Overall, the results obtained are promising. They reveal the negligible propensity of AS-48 to cause cell death or impede cell growth at therapeutic concentrations (up to 27⯵M) and support the suitability of this peptide as a potential therapeutic agent against several microbial infections, due to its selectivity and potency at low concentrations (in the range of 0.3-8.9⯵M). In addition, AS-48 exhibits low haemolytic activity in whole blood and does not induce nitrite accumulation in non-stimulated RAW macrophages, indicating a lack of pro-inflammatory effects. The unexpected heightened sensitivity of zebrafish embryos to AS-48 could be due to the low differentiation state of these cells. The low cytotoxicity of AS-48, the absence of lymphocyte proliferation in vivo after skin sensitization in mice, and the lack of toxicity in a murine model support the consideration of the broad spectrum antimicrobial peptide AS-48 as a promising therapeutic agent for the control of a vast array of microbial infections, in particular, those involved in skin and soft tissue diseases.
ABSTRACT
The current chemotherapy against Chagas disease is inadequate and insufficient. A series of ten Mannich base-type derivatives have been synthesized to evaluate their in vitro antichagasic activity. After a preliminary screening, compounds 7 and 9 were subjected to in vivo assays in a murine model. Both compounds caused a substantial decrease in parasitemia in the chronic phase, which was an even better result than that of the reference drug benznidazole. In addition, compound 9 also showed better antichagasic activity during the acute phase. Moreover, metabolite excretion, effect on mitochondrial membrane potential and the inhibition of superoxide dismutase (SOD) studies were also performed to identify their possible mechanism of action. Finally, docking studies proposed a binding mode of the Fe-SOD enzyme similar to our previous series, which validated our design strategy. Therefore, the results suggest that these compounds should be considered for further preclinical evaluation as antichagasic agents.
Subject(s)
Chagas Disease/drug therapy , Mannich Bases/pharmacology , Superoxide Dismutase/antagonists & inhibitors , Trypanocidal Agents/pharmacology , Trypanosoma cruzi/drug effects , Animals , Cells, Cultured , Chagas Disease/metabolism , Chlorocebus aethiops , Cyclophosphamide/administration & dosage , Cyclophosphamide/pharmacology , Dose-Response Relationship, Drug , Humans , Injections, Intraperitoneal , Mannich Bases/chemical synthesis , Mannich Bases/chemistry , Mice , Mice, Inbred BALB C , Molecular Docking Simulation , Molecular Structure , Parasitic Sensitivity Tests , Structure-Activity Relationship , Superoxide Dismutase/metabolism , Trypanocidal Agents/chemical synthesis , Trypanocidal Agents/chemistry , Trypanosoma cruzi/metabolism , Vero CellsABSTRACT
Chagas disease caused by the protozoan parasite Trypanosoma cruzi represents a significant public health problem in Latin America, affecting around 8 million cases worldwide. Nowadays is urgent the identification of new antichagasic agents as the only therapeutic options available, Nifurtimox and Benznidazole, are in use for >40 years, and present high toxicity, limited efficacy and frequent treatment failures in the chronic phase of the disease. Recently, it has been described the antiparasitic effect of AS-48, a bacteriocin produced by Enterococcus faecalis, against Trypanosoma brucei and Leishmania spp. In this work, we have demonstrated the in vitro potential of the AS-48 bacteriocin against T. cruzi. Interesting, AS-48 was more effective against the three morphological forms of different T. cruzi strains, and displayed lower cytotoxicity than the reference drug Benznidazole. In addition, AS-48 combines the criteria established as a potential antichagasic agent, resulting in a promising therapeutic alternative. According to the action mechanism, AS-48 trypanocidal activity could be explained in a mitochondrion-dependent manner through a reactive oxygen species production and mitochondrial depolarization, causing a fast and severe bioenergetic collapse.
Subject(s)
Bacteriocins/pharmacology , Chagas Disease/parasitology , Trypanocidal Agents/pharmacology , Trypanosoma cruzi/drug effects , Animals , Bacteriocins/metabolism , Chagas Disease/drug therapy , Enterococcus faecalis/chemistry , Enterococcus faecalis/metabolism , Mitochondria/drug effects , Mitochondria/metabolism , Nitroimidazoles/pharmacology , Reactive Oxygen Species/metabolism , Trypanocidal Agents/metabolism , Trypanosoma cruzi/growth & development , Trypanosoma cruzi/metabolismABSTRACT
Chagas Disease is caused by infection with the insect-transmitted protozoan Trypanosoma cruzi and affects more than 10 million people. It is a paradigmatic example of a chronic disease without an effective treatment in Latin America where the current therapies, based on Benznidazole and Nifurtimox, are characterised by limited efficacy, toxic side-effects and frequent failures in the treatment. We present a series of new long-chain squaramides, identified based on their 1H and 13C NMR spectra, and their trypanocidal activity and cytotoxicity were tested in vitro through the determination of IC50 values. Compounds 4 and 7 were more active and less toxic than the reference drug Benznidazole, and these results were the basis of promoting in vivo assays, where parasitaemia levels, assignment of cure, reactivation of parasitaemia and others parameters were determined in mice treated in both the acute and chronic phases. Finally, the mechanisms of action were elucidated at metabolic and mitochondrial levels and superoxide dismutase inhibition. The experiments allowed us to select compound 7 as a promising candidate for treating Chagas Disease, where the activity, stability and low cost make long-chain squaramides appropriate molecules for the development of an affordable anti-chagasic agent versus current treatments.
Subject(s)
Chagas Disease/drug therapy , Cyclobutanes/therapeutic use , Trypanocidal Agents/therapeutic use , Animals , Chlorocebus aethiops , Cyclobutanes/chemical synthesis , Cyclobutanes/toxicity , DNA/metabolism , Female , Membrane Potential, Mitochondrial/drug effects , Mice, Inbred BALB C , RNA/metabolism , Splenomegaly/drug therapy , Superoxide Dismutase/metabolism , Trypanocidal Agents/chemical synthesis , Trypanocidal Agents/toxicity , Trypanosoma cruzi/drug effects , Vero CellsABSTRACT
Currently, only two drugs (i.e. benznidazole (BZN) and nifurtimox (NFX)) have been approved for the treatment of Trypanosoma cruzi (Tc) infection, the etiological agent causing Chagas disease. Since both drugs exhibit severe side effects, patients frequently abandon therapy, resulting in an inefficient pharmacotherapeutic treatment. In this context, there is an urgent need to develop new, safer and optimised anti-Tc agents. In this report, we present the synthesis and biological activity of 11 novel and 3 already reported N-arylsulfonyl-benzimidazole derivatives (NBSBZD,1-14) currently in development as potential anti-Tc compounds. These compounds were designed as part of a library of synthetic arylsulfonyl heterocycle derivatives constructed from privileged structures exhibiting drug-like properties. Based on bioactivity assays against Tc, (in both the extracellular and intracellular forms), we observed that 10 compounds exhibited bioactivity against the epimastigote form, while six of them exhibited activity against the amastigote counterpart. Also, the compounds showed less cytotoxicity compared to the reference drug BZN as measured in Vero cell culture. In order to elucidate the potential mechanism of action, metabolite excretion profiles studies were performed, and complemented with molecular modeling studies performed over known Tc druggable targets. Consistency was observed between experimental and theoretical findings, with metabolic profiles showing that compounds 1, 2, 9, 12 and 14 interfered with the normal glycolysis cycle of Tc, while molecular modeling studies were able to establish a solid structure-activity relationship towards the inhibition of 6-phospho-1-fructokinase, a key enzyme involved in the parasite glycolytic cascade. Overall, the present study constitutes a multidisciplinary contribution to the development of new anti-Chagas compounds.
Subject(s)
Benzimidazoles/pharmacology , Drug Design , Trypanocidal Agents/chemical synthesis , Trypanosoma cruzi/drug effects , Animals , Benzimidazoles/chemical synthesis , Benzimidazoles/therapeutic use , Chagas Disease/drug therapy , Chlorocebus aethiops , Molecular Docking Simulation , Trypanocidal Agents/pharmacology , Vero CellsABSTRACT
Chagas disease is a neglected chronical parasitosis caused by the parasite Trypanosoma cruzi (T. cruzi). Nine ferrocenyl Mannich base derivatives were synthetized and characterized to explore their in vitro activity on three T. cruzi strains of the parasite and their cytotoxicity on Vero cells to calculate the selectivity index (SI). Compound 2, 1-ferrocenyl-3-(4-(4-(trifluoromethyl)phenyl)piperazin-1-yl)propan-1-one, stood out as the most promising derivative showing a half maximal inhibitory concentration (IC50) value around 5⯵M in both amastigote and trypomastigote forms of T. cruzi and SI values higher than 13, being the best value on the trypomastigote forms of the Arequipa strain (SIâ¯=â¯41.7). Moreover, 2 decreased the number of infected cells and was not genotoxic. Furthermore, its possible mechanism of action was studied through the alteration of the metabolites excreted by the parasite during glucose metabolism, the detection of mitochondrial alterations and the inhibition of superoxide dismutase (SOD). Finally, docking studies were executed to analyze the binding mode of the studied compounds to Fe-SOD enzyme.