Topical treatment of experimental cutaneous leishmaniasis in golden hamster (Mesocricetus auratus) with formulations containing pentamidine

Current treatment of cutaneous leishmaniasis (CL) relies mainly on pentavalent antimonials salts and second-line drugs include pentamidine and amphotericin B, but these therapies have side effects and require parenteral administration. The aim of this work was to evaluate the topical formulations containing pentamidine isethionate (PI) in the experimental treatment of cutaneous leishmaniasis (CL). Golden hamsters (Mesocricetus auratus) were infected in the nose with Leishmania (Leishmania) amazonensis. Six treatment groups received different topical treatments of anhydrous or hydrating emulsions, for a maximum of 10 days, with an application of 50 mg day(-1). After treatment tissue samples of lesions were evaluated by histology, transmission electron microscopy and biopsy cultivation. Compared with untreated group, topical treatment with hydrating emulsion with 10% PI and usnic acid (ACE5AU) showed significantly decrease in volume lesion (P= 0.028) on 20th day after the end of the treatment with reduction of 27.37%. Topical treatment with anhydrous emulsion with 10% PI and usnic acid (ACPU) reduces parasite burden in Golden hamsters. This study demonstrated the potential of topical treatment to reduce the number of parasites that could be combined with others drugs and to have a faster and more effective treatment of cutaneous leishmaniasis.Peer reviewe

Vectors of Trypanosomatids (Kinetoplastida: Trypanosomatidae) in Tabatinga, Amazonas, Brazil

The sand flies transmit diseases to humans and animals, such as arboviruses and bartonellosis, besides the leishmaniasis. The objective of this research was identified potential vectors of this disease in the municipality of Tabatinga. Sand flies were captured with Miniature Light Trap and manual collection by aspiration at the bases of trees. In the months of August 2010 and 2011, were captured 4,542 sand flies (♂: 71.9% and ♀: 28.1%) vectors or suspected of trypanosomatids transmission, belonging to 13 species. The most abundant species was Lutzomyia umbratilis with 78.7%. A total of 576 (74,0%) sand flies of the genus Lutzomyia were dissected and natural infection by trypanosomatids was observed in 44 females. Blood in decomposition was detected at the digestive tract in 86.3% insects; being 59,0% of the ovaries in developing. The isoenzymatic analysis of ten isolates showed similar profiles to Leishmania colombiensis and Endotrypanum sp., however, the profile of the locus Malate Dehydrogenase (MDH) showed major similarity to the genus Endotrypanum. This is the first investigation of the fauna entomology and attempt of trypanosomatids isolation in the municipality of Tabatinga, area of triple border with Brazil

The Role of Inflammatory, Anti-Inflammatory, and Regulatory Cytokines in Patients Infected with Cutaneous Leishmaniasis in Amazonas State, Brazil

The authors discuss in this paper the role of inflammatory, anti-inflammatory, and regulatory cytokines in patients infected with different species of Leishmania in Amazonas State, Brazil. A comparative analysis was made of serum concentrations of these cytokines in the peripheral blood of 33 patients infected with cutaneous leishmaniasis. The isolates were identified as Leishmania guyanensis, L. naiffi, and L. amazonensis. Most (64%) of the patients were male ranging in age from 18 to 58 years. Protein expression profiles of IL-2, IL-4, IL-6, IL-10, IFN-γ, TNF-α, and IL-17 cytokines were shown to vary significantly between infected and noninfected (control group) individuals and according to the Leishmania species. Infection caused by L. guyanensis accounted for 73% of the cases and patients with this parasite also showed higher concentrations of IL-2, IFN-γ, IL-4, and IL-17 when compared to infection by L. amazonensis. Patients with infection caused by L. naiffi showed higher concentration of the cytokines analyzed when compared to uninfected patients; however, there was no statistically significant difference with the other species analyzed

Avaliação in vitro da atividade antileishmania de complexos de cobre (I)

In the research for the development of new drugs for the therapy of American tegumentary leishmaniasis, copper has been studied for its antileishmania activity. This study aims to report the activity of three copper(I) complexes on parasites of the species L. amazonensis and L. guyanensis. The metal complexes were tested according to in vitro antileishmanial assays, against promastigote and amastigote forms of the most prevalent species in the state of Amazonas, Brazil. Cytotoxicity of the complexes was evaluated in murine macrophage-like cell line (MJ774). The results of the in vitro assays indicated that, among the copper complexes tested, the homoleptic phosphine complex [Cu(thp)4][PF6](thp=tris-hydroxymethylphosphine) presented promising activity against the evolutionary forms of L. amazonensis, and obtained a IC50 of  26.45 and 24.61 µM in a period of 48 and 72 h, respectively. The results for copper complex at concentration 160 µM in amastigote forms showed a decrease in the infection index (32% of infected cells) and, in the cytotoxicity assay with MJ774, 52.43% of cell viability was observed. The results showed that the complex [Cu(thp)4][PF6] presented significant biological activity, indicating a need for future in vivo studies.Na busca do desenvolvimento de novos fármacos para a terapia da leishmaniose tegumentar americana, o cobre tem sido estudado quanto a sua atividade antileishmania. Esse estudo tem como objetivo relatar a atividade de três complexos de cobre (I) sobre parasitas das espécies L. amazonensis e L. guyanensis. Os complexos metálicos foram testados por meio de ensaios antileishmania in vitro contra as formas promastigota e amastigota das espécies mais prevalentes no estado do Amazonas, Brasil. A citotoxicidade dos complexos foi avaliada em linhagem de células semelhantes a macrófagos murinos (MJ774). Os resultados dos ensaios in vitro indicaram que, entre os complexos de cobre testados, o complexo homoléptico de fosfina [Cu(thp)4][PF6](thp=tris-hidroximetilfosfina) apresentou atividade promissora contra as formas evolutivas de L. amazonensis, e obtiveram IC50 de 26,45 e 24,61 µM em um período de 48 e 72 h, respectivamente. Os resultados para o complexo de cobre na concentração de 160 µM nas formas amastigotas reportaram diminuição no índice de infecção (32% das células infectadas) e, no ensaio de citotoxicidade com MJ774, observou-se 52,43% de viabilidade celular. Os resultados evidenciaram que o complexo [Cu(thp)4][PF6] apresentou atividade biológica significativa, indicando a necessidade de futuros estudos in vivo

Minicircle kDNA microheterogeneity in Endotrypanum indicate diversity within this genus.

A comparison of kDNA restriction-endonuclease fragment patterns from strains representing selected Endotrypanum zymodemes was done by schizodeme analysis. As the degree of heterogeneity within mini-circles varied among species or strains of Endotrypanum, the fingerprint obtained with each of the restriction enzymes was unique for each of these parasites. The data have revealed that this trypanosomatid genus is much more complex than it was originally thought to be

Antileishmanial activity of extracts from Libidibia ferrea : development of in vitro and in vivo tests

Treatment of cutaneous leishmaniasis (CL) is difficult due to the scarce number of drugs able to eliminate completely the intracellular form of the parasite. In the present study, the aim was to evaluate: i) phytochemical properties of extracts from Libidibia ferrea; ii) antileishmanial activity of extracts from L. ferrea against promastigotes and amastigotes of Leishmania (Leishmania) amazonensis and Leishmania (Viannia) guyanensis; iii) the effects of topical treatment using hydrogel containing active extract of L. ferrea on golden hamsters infected with L. (L.) amazonensis. Extracts from leaves, branches and fruits of L. ferrea were obtained with hexane and methanol and were tested by in vitro assays in promastigotes and murine macrophages J774 experimentally infected with amastigotes of Leishmania. Groups of hamsters with CL received topical treatment with a formulation of extract (10%) hydrogels, 50 mg. day(-1) for 40 days. In vitro activity of FrMeOH (methanolic extract from fruits without seeds) resulted in significant reduction of viable promastigotes of L. (L.) amazonensis (IC50 of 15.4 mu g. mL(-1)) and demonstrated inhibition potential of amastigote forms of L. (L.) amazonensis and L. (V.) guyanensis and low cytotoxicity in macrophages. The overall data of topical treatment with extract hydrogels (GelFrMeOH) showed that lesion sizes were significantly reduced (42.78%), with low parasite burden by RT-qPCR and culture analysis by microscopy examination, and with histopathological findings such as lower inflammatory cell infiltration 40 days after treatment. Chemical analysis demonstrated FrMeOH contains high levels of phenolic compounds. The results indicate a possible alternative therapy for CL using phytotherapics. KEYWORDS: cutaneous leishmaniasis, natural products, topical formulations, experimental treatmentPeer reviewe

Potencial dos análogos do dilapiol para uso em Doenças Negligenciadas, com ênfase para Leishmaniose Cutânea: revisão literária / Potential of dilapiol analogues for use in Neglected Diseases, with emphasis on Cutaneous Leishmaniasis: a literature review

As Doenças Tropicais Negligenciadas (DTNs) são um grupo de doenças que afetam principalmente a população de países tropicais e em desenvolvimento de baixa a média renda. Nos últimos anos, no cenário internacional, tem havido debates sobre as formas de prevenir, combater e erradicar as doenças tropicais negligenciadas, bem como pesquisas para desenvolver novos fármacos que ajudem no tratamento dessas doenças, onde através da literatura obtivemos inúmeros estudos científicos mostrando moléculas bioativas provenientes de plantas com atividades biológicas, dentre elasPiper aduncum, já que seu composto majoritário, o dilapiol, apresenta uma estrutura química natural que pode ser modificada através de semissíntese, uma alternativa de obtenção de novas moléculas ativas, esses análogos do dilapiol, testados sobre doenças negligenciadas, principalmente contra leishmaniose cutânea, inibindo as formas promastigotas e amastigotas de Leishmania de diversas espécies.

In vitro and in vivo activity of a hypotoxic copper(I) complex against dermotropic Leishmania species

ABSTRACT Cutaneous leishmaniasis is a disease caused by protozoa of the genus Leishmania and, currently, the treatment of first choice is meglumine antimoniate. However, due to its limited effectiveness and high toxicity, it is necessary to seek new active principles for leishmaniasis treatment. Metal complexes are gaining importance due to their effectiveness and low toxicity. In this context, the present study aimed to evaluate the in vitro and in vivo antileishmanial activity of the hypotoxic copper(I) complex [HB(pz)3]Cu(PCN). Four dermotropic species of Leishmania were tested with the metal complex and its effectiveness was determined through parasitic viability and infectivity rate, and cytotoxicity was determined using a redox dye (resazurin). For the in vivo tests, hamsters were infected and the lesions treated with a formulated ointment containing the complex, the effectiveness of which was assessed by measuring the diameter of the inoculum/snout location and determining the parasitic load. The results demonstrated moderate toxicity in murine macrophages and human monocytes and better efficacy in Leishmania (V.) braziliensis when compared to the other species tested, with a 50% reduction in the viability of promastigote and amastigote forms (in vitro). General data from daily topical treatment for up to 30 days showed low efficacy for reducing lesions, and no clinical and parasitological cure was observed in the experimental animals. Thus, the [HB(pz)3]Cu(PCN) complex proved to be promising in in vitro studies against L. (V.) braziliensis, and should be further tested in new formulations and new experimental treatment schemes

Avaliação da linfoproliferação de células mononucleares de pacientes com leishmaniose cutânea frente a Libidibia ferrea

American integumentary leishmaniasis (ATL) is a neglected disease that mostly affects vulnerable populations. Its broad spectrum of clinical manifestations is related to the type of immune response produced by the host and the species of Leishmania involved. In recent years, the use of medicinal plants has become a therapeutic alternative in the treatment of infectious parasitic diseases. This research aimed to evaluate the lymphoproliferative responses of peripheral blood mononuclear cells (PBMCs) of patients with cutaneous leishmaniasis (CL) before and after treatment, and healthy individuals. The lymphoproliferative response was evaluated in cell culture using stimuli of the dichloromethane fraction (DCM) obtained from Libidibia ferrea, Glucantime® and phytohemagglutinin - PHA using a BrdU Cell Proliferation after 72 h of incubation. In cultures treated with the DCM fraction, intense induction of lymphoproliferation was observed (p<0.0001), as was also observed in response to the PHA mitogen, and there was a significant difference when compared with the conventional treatment (p<0.0135). In the post-treatment and healthy groups, although the compound induced lymphoproliferation, there was no statistical difference. These results suggest that the organic compound played an important inducing role in lymphoproliferation, which highlights the importance of continuity involving new studies in order to evaluate its immunomodulatory activity.A leishmaniose tegumentar americana (LTA) é uma doença negligenciada que acomete majoritariamente populações vulneráveis. Seu amplo espectro de manifestações clínicas é relacionado ao tipo de resposta imunológica produzida pelo hospedeiro e a espécie de Leishmania envolvida. Nos últimos anos, o uso de plantas medicinais vem sendo uma alternativa terapêutica no tratamento de doenças infectoparasitárias. Esta pesquisa teve como objetivo avaliar as respostas linfoproliferativas de células mononucleares do sangue periférico (PBMCs) de pacientes com leishmaniose cutânea (LC) antes e após tratamento e de indivíduos sadios. A resposta linfoproliferativa foi avaliada em cultura de células frente a estímulos da fração diclorometânica (DCM) obtida de Libidibia ferrea, Glucantime® e phytohemagglutinin - PHA utilizando BrdU Cell Proliferation após 72h de incubação. Nas culturas tratadas com a fração DCM foi observada em todos os grupos intensa indução da linfoproliferação (p<0,0001), apresentando diferença significativa ao comparar com o tratamento convencional no grupo de pacientes pós-tratamento (p<0,0135). Estes resultados sugerem que o composto orgânico desempenhou importante ação indutora na linfoproliferação ressaltando a importância da continuidade com novos estudos a fim de avaliar sua atividade imunomodulatória

The Role of Inflammatory, Anti-Inflammatory, and Regulatory Cytokines in Patients Infected with Cutaneous Leishmaniasis in Amazonas State, Brazil

The authors discuss in this paper the role of inflammatory, anti-inflammatory, and regulatory cytokines in patients infected with different species of Leishmania in Amazonas State, Brazil. A comparative analysis was made of serum concentrations of these cytokines in the peripheral blood of 33 patients infected with cutaneous leishmaniasis. The isolates were identified as Leishmania guyanensis, L. naiffi, and L. amazonensis. Most (64%) of the patients were male ranging in age from 18 to 58 years. Protein expression profiles of IL-2, IL-4, IL-6, IL-10, IFN-, TNF-, and IL-17 cytokines were shown to vary significantly between infected and noninfected (control group) individuals and according to the Leishmania species. Infection caused by L. guyanensis accounted for 73% of the cases and patients with this parasite also showed higher concentrations of IL-2, IFN-, IL-4, and IL-17 when compared to infection by L. amazonensis. Patients with infection caused by L. naiffi showed higher concentration of the cytokines analyzed when compared to uninfected patients; however, there was no statistically significant difference with the other species analyzed