RESUMO
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.
Assuntos
Doença de Chagas/tratamento farmacológico , Compostos de Piridínio/farmacologia , Tripanossomicidas/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Animais , Morte Celular/efeitos dos fármacos , Reposicionamento de Medicamentos , Humanos , Leishmaniose/tratamento farmacológico , Membranas Mitocondriais/metabolismo , Estresse Oxidativo/efeitos dos fármacos , América do Sul , Superóxido Dismutase/metabolismo , Tripanossomíase Africana/tratamento farmacológicoRESUMO
The activity of a family scorpiand-like azamacrocycles against Leishmania infantum and Leishmania braziliensis was studied using promastigotes, axenic and intracellular amastigotes forms. All the compounds are more active and less toxic than meglumine antimoniate (Glucantime). Moreover, the data on infection rates and amastigotes showed that compounds P2Py, PN and P3Py are the most active against both species of Leishmania. On the other hand, studies on the inhibitory effect of these compounds on SOD enzymes showed that while the inhibition of the Fe-SOD enzyme of the promastigote forms of the parasites is remarkable, the inhibition of human CuZn-SOD and Mn-SOD from Escherichia coli is negligible. The ultrastructural alterations observed in treated promastigote forms confirmed that the compounds having the highest activity were those causing the largest cell damage. The modifications observed by (1)H NMR, and the amounts of catabolites excreted by the parasites after treatment with the compounds, suggested that the catabolic mechanism could depend on the structure of the side chains linked to the aza-scorpiand macrocycles.
Assuntos
Antiprotozoários/farmacologia , Compostos Aza/farmacologia , Leishmania braziliensis/efeitos dos fármacos , Leishmania infantum/efeitos dos fármacos , Compostos Macrocíclicos/farmacologia , Antiprotozoários/síntese química , Antiprotozoários/química , Compostos Aza/síntese química , Compostos Aza/química , Relação Dose-Resposta a Droga , Compostos Macrocíclicos/síntese química , Compostos Macrocíclicos/química , Estrutura Molecular , Testes de Sensibilidade Parasitária , Relação Estrutura-AtividadeRESUMO
The activity of five (1-5) abietane phenol derivatives against Leishmania infantum and Leishmania braziliensis was studied using promastigotes and axenic and intracellular amastigotes. Infectivity and cytotoxicity tests were performed with J774.2 macrophage cells using Glucantime as a reference drug. The mechanisms of action were analysed by performing metabolite excretion and transmission electron microscopy ultrastructural studies. Compounds 1-5 were more active and less toxic than Glucantime. The infection rates and mean number of parasites per cell observed in amastigote experiments showed that derivatives 2, 4 and 5 were the most effective against both L. infantum and L. braziliensis. The ultrastructural changes observed in the treated promastigote forms confirmed that the greatest cell damage was caused by the most active compound (4). Only compound 5 caused changes in the nature and amounts of catabolites excreted by the parasites, as measured by ¹H nuclear magnetic resonance spectroscopy. All of the assayed compounds were active against the two Leishmania species in vitro and were less toxic in mammalian cells than the reference drug.
Assuntos
Animais , Feminino , Camundongos , Antiprotozoários/farmacologia , Leishmania braziliensis/efeitos dos fármacos , Leishmania infantum/efeitos dos fármacos , Macrófagos/parasitologia , Terpenos/farmacologia , Antiprotozoários/química , Leishmania braziliensis/ultraestrutura , Leishmania infantum/ultraestrutura , Espectroscopia de Ressonância Magnética , Camundongos Endogâmicos BALB C , Microscopia Eletrônica de Transmissão , Testes de Sensibilidade Parasitária , Terpenos/químicaRESUMO
The activity of five (1-5) abietane phenol derivatives against Leishmania infantum and Leishmania braziliensis was studied using promastigotes and axenic and intracellular amastigotes. Infectivity and cytotoxicity tests were performed with J774.2 macrophage cells using Glucantime as a reference drug. The mechanisms of action were analysed by performing metabolite excretion and transmission electron microscopy ultrastructural studies. Compounds 1-5 were more active and less toxic than Glucantime. The infection rates and mean number of parasites per cell observed in amastigote experiments showed that derivatives 2, 4 and 5 were the most effective against both L. infantum and L. braziliensis. The ultrastructural changes observed in the treated promastigote forms confirmed that the greatest cell damage was caused by the most active compound (4). Only compound 5 caused changes in the nature and amounts of catabolites excreted by the parasites, as measured by ¹H nuclear magnetic resonance spectroscopy. All of the assayed compounds were active against the two Leishmania species in vitro and were less toxic in mammalian cells than the reference drug.
Assuntos
Antiprotozoários/farmacologia , Leishmania braziliensis/efeitos dos fármacos , Leishmania infantum/efeitos dos fármacos , Macrófagos/parasitologia , Terpenos/farmacologia , Animais , Antiprotozoários/química , Feminino , Concentração Inibidora 50 , Leishmania braziliensis/ultraestrutura , Leishmania infantum/ultraestrutura , Espectroscopia de Ressonância Magnética , Camundongos , Camundongos Endogâmicos BALB C , Microscopia Eletrônica de Transmissão , Testes de Sensibilidade Parasitária , Terpenos/químicaRESUMO
A superoxide dismutase excreted by promastigote forms of L. (Viannia) peruviana (SODe-Lp), L. (Viannia) brazilensis (SODe-Lb), and L. (L.) amazonensis (SODe-La) is tested to evaluate its potential value as a diagnostic tool of mucocutaneous and Andean cutaneous leishmaniasis. We used 45 sera with mucocutaneous leishmaniasis (SL) and 68 with Andean cutaneous leishmaniasis (ACL). SODe-Lp antigen was recognized by 94% of the serum from ACL patients, and the SODe-Lb antigen was recognized by 93% of the serum from SL patients. Meanwhile, the result for SL and ACL patients with SODe-La antigen was 69% and 43% and SODe-Li was 11% and 9%, respectively. This suggest that antibodies to SODe-Lp undergo further response in patients with ACL and the antibodies to SODe-Lb do so preferentially in patients with SL. The SODe ELISA may be useful in endemic areas for discriminative assays between patients with different forms of leishmaniases and those with other clinical conditions.
Assuntos
Antígenos de Protozoários/análise , Leishmaniose Cutânea/diagnóstico , Superóxido Dismutase/análise , Animais , Antígenos de Protozoários/sangue , Ensaio de Imunoadsorção Enzimática , Humanos , Focalização Isoelétrica , Leishmania braziliensis/enzimologia , Leishmania infantum/enzimologia , Leishmaniose Cutânea/sangue , Peru , Superóxido Dismutase/sangueRESUMO
Seven trypanosome stocks isolated have been characterized by lectin agglutination, isoenzyme analysis, and the end products excreted. The stocks were isolated from different geographic areas-one from Mexico (TM5), and six from Peru, four of these isolated from different species of triatoma (TP504, TP702, TP704 and TP706), the other two isolated from the salivary glands of Rhodnius ecuadorensis (TRa605 and TRa606). Additionally, one strain of Trypanosoma cruzi isolated from a human case (strain TC-Maracay) and one strain of T. rangeli (TRa, Cajamarca-Peru strain), characterized and maintained in our laboratory, were used as reference strains. According to statistical study, the stocks were grouped into three clusters: (1) cluster I included the reference strain of T. cruzi (TC-Maracay); (2) cluster II was subdivided into two groups-subcluster IIA for the Mexican isolate (TM5) and subcluster IIB for the Peruvian ones, isolated from the salivary glands of Rhodnius ecuadorensis (TRa 605 and TRa 606) and the reference strain T. rangeli (TRa); these two new isolates were classified as T. rangeli; and (3) cluster III for the rest of the Peruvian isolates, which should be considered at least as a different strain from the T. cruzi strain Maracay. We show that the identification of T. cruzi and T. rangeli in mixed infections is readily achieved by biochemical methods. These findings identified three clusters of Mexican and Peruvian stocks that correlate with geographic origin, although assignment to a T. cruzi linage was not possible.
Assuntos
Doença de Chagas/epidemiologia , Trypanosoma cruzi/classificação , Trypanosoma cruzi/metabolismo , Trypanosoma/classificação , Trypanosoma/metabolismo , Tripanossomíase/epidemiologia , Testes de Aglutinação , Animais , Doença de Chagas/parasitologia , Humanos , Isoenzimas/análise , Lectinas/metabolismo , Espectroscopia de Ressonância Magnética , México , Peru , Trypanosoma/isolamento & purificação , Trypanosoma cruzi/isolamento & purificação , Tripanossomíase/parasitologiaRESUMO
Cryptosporidium parvum and C. muris appear to be different species found in calves, with different oocysts size and distribution on the gastrointestinal tract. This work presents new images of C. parvum ultrastructure in calf intestine, mainly its development in nonmicrovillous cells and the presence of microtubular structures in the membrane enveloping the microgamonts and immature oocysts.