Larval excretion/secretion of dipters of Lucilia cuprina species induces death in promastigote and amastigote forms of Leishmania amazonensis.

Leishmaniasis is a neglected tropical disease that affects millions of people around the world. Larval excretion/secretion (ES) of the larvae of flies of the Calliphoridae family has microbicidal activity against Gram-positive and Gram-negative bacteria, in addition to some species of Leishmania. Our study aimed at assessing the in vitro efficacy of Lucilia cuprina larval ES against the promastigote and amastigote forms of Leishmania amazonensis, elucidating possible microbicidal mechanisms and routes of death involved. Larval ES was able to inhibit the viability of L. amazonensis at all concentrations, induce morphological and ultrastructural changes in the parasite, retraction of the cell body, roughness of the cytoplasmic membrane, leakage of intracellular content, ROS production increase, induction of membrane depolarization and mitochondrial swelling, the formation of cytoplasmic lipid droplets and phosphatidylserine exposure, thus indicating the possibility of apoptosis-like death. To verify the efficacy of larval ES on amastigote forms, we performed a phagocytic assay, measurement of total ROS and NO. Treatment using larval ES reduced the percentage of infection and the number of amastigotes per macrophage of lineage J774A.1 at all concentrations, increasing the production of ROS and TNF-α, thus indicating possible pro-inflammatory immunomodulation and oxidative damage. Therefore, treatment using larval ES is effective at inducing the death of promastigotes and amastigotes of L. amazonensis even at low concentrations.

Leishmaniasis patients' pilgrimage to access health care in rural Bolivia: a qualitative study using human rights to health approach.

BACKGROUND: Leishmaniasis is a neglected tropical disease endemic in Bolivia that disproportionately affects people with little social and political capital. Although the treatment is provided free of charge by the Bolivian government, there is an under-utilization of treatments in relation to the estimated affected population. This study explores the experiences of patients with leishmaniasis and the challenges faced when searching for diagnosis and treatment in Bolivia using a human rights approach. METHODS: We conducted open-ended interviews with 14 participants diagnosed with leishmaniasis. The qualitative data were analysed using thematic analysis and were interpreted under a human rights approach to health care. RESULTS: Four themes emerged during data analysis: (1) the decision for seeking a cure takes time; (2) the severity of symptoms and disruption of functioning drives the search for Western medicine; (3) the therapeutic journey between Western and traditional medicine; and (4) accessibility barriers to receive adequate medical treatment. This study showed that access to health care limitations were the most important factors that prevented patients from receiving timely diagnosis and treatment. Cultural factors played a secondary role in their decision to seek medical care. CONCLUSIONS: Accessibility barriers resulted in a large pilgrimage between public health care and traditional medicinal treatments for patients with leishmaniasis. This pilgrimage and the related costs are important factors that determine the decision to seek health care. This study contributes to the understanding of the under-utilisation problems of medical services in leishmaniasis and other similar diseases in remote and poor populations.

Avaliação da atividade anti-Leishmania e anti-Trypanosoma do extrato etanólico das folhas de Annona squamosa L / Evaluation of the anti-leishmania and anti-trypanosoma activity of ethanolic extract from the leaves of Annona squamosa L

As doenças parasitárias, também chamadas de “doenças negligenciadas”, continuam sendo uma grande dificuldade para o desenvolvimento social e econômico dos países mais pobres. Podemos citar como exemplo dessas doenças, a leishmaniose e a doença de Chagas. A leishmaniose é causada por parasitas do gênero Leishmania e afeta cerca de 12 milhões de pessoas. A doença de Chagas, causada pelo protozoário Trypanosoma cruzi, causa aproximadamente 50.000 mortes por ano. Os fármacos disponíveis para o tratamento dessas doenças são altamente tóxicos, sendo este um dos motivos que leva à busca por drogas eficazes e seguras para seus tratamentos. As folhas da Annona squamosa, espécie da família Annonaceae, já foram descritas na literatura por suas atividades hepatoprotetora, antiparasitária, pesticida e antimicrobiana. Nesse estudo avaliamos a atividade anti-leishmania e tripanocida do extrato etanólico das folhas de Annona squamosa L. (EEAS) em formas promastigota do parasita Leishmania braziliensis e Leishmania infantum e epimastigota de Trypanosoma cruzi, além de avaliar a atividade citotóxica em fibroblasto. Os resultados demonstram que o extrato apresentou uma melhor atividade contra Leishmania infantum e Leishmania brasiliensis quando comparados com Trypanosoma cruzi; e que apresentou uma maior toxicidade nas concentrações de 500 e 1000 μg/ml, com mortalidade dos fibroblastos de aproximadamente 85% e 100%, respectivamente. Esse estudo aponta para uma perspectiva terapêutica alternativa que se mostrou eficaz frente aos parasitas aqui estudados, exceto a forma epimastigota de Trypanosoma cruzi. Com relação aos testes de citotoxicidade fazem-se necessários novos testes, uma vez que apresentou um alto nível de toxicidade, viabilizando assim futuros ensaios in vivo.

The parasitic diseases, also calls by “neglected diseases”, continue being a major difficulty for the social and economic development of the poorest countries. We can cite as an example of these diseases, the leishmaniasis and the Chagas disease. Leishmaniasis is caused by parasites of the genus Leishmania and affects about 12 million people. The Chagas disease, caused by the protozoan Trypanosoma cruzi, causes approximately 50,000 deaths per year. The drugs available for the treatment of these diseases are highly toxic, being this one of the reasons that leads to the search for effective and safe drugs for their treatments. The leaves of the Annona squamosa, species of the family Annonaceae, have already been described in the literature by their hepatoprotective activities, antiparasitic, pesticide and antimicrobial. In this study we assessed the activity tripanocidal and antileishmania of ethanolic extract from the leaves of Annona squamosa L. (EEAS) in promastigota forms of the parasite Leishmania braziliensis and Leishmania infantum and epimastigota of Trypanosoma cruzi, in addition to evaluating the cytotoxic activity in fibroblasts. The results demonstrate that the extract presented a better activity against Leishmania infantum and Leishmania brasiliensis when compared with Trypanosoma cruzi; and which presented a greater toxicity at concentrations of 500 and 1000 μg/ml, with mortality of fibroblasts of approximately 85% and 100%, respectively. This study points to an alternative therapeutic perspective that showed effective against the parasites here studied, except the epimastigota form of Trypanosoma cruzi. With relation to cytotoxicity tests are required new tests, once presented a high level of toxicity, thus enabling future in vivo assays.

Productos naturales con actividad leishmanicida y tripanocida / Natural products with leishmanicidal and trypanocidal activity

Las enfermedades parasitarias constituyen un importante problema de salud, y muchas de ellas están emergiendo en países donde se consideraban erradicadas. La leishmaniasis, la enfermedad del sueño y la enfermedad de Chagas, causadas por los parásitos Leishmania spp, Trypanosoma brucei y Trypanosoma cruzi, respectivamente, se encuentran entre las enfermedades parasitarias más prevalentes. La principal alternativa para tratarlas es la quimioterapia. Sin embargo, los tratamientos actuales se encuentran lejos de ser satisfactorios. La toxicidad de los fármacos, la vía de administración, la duración de los tratamientos y la aparición de resistencias hacen necesario el desarrollo de nuevas moléculas activas, más seguras y eficaces. Estudios recientes ponen de manifiesto la actividad leishmanicida y tripanocida in vivo de una amplia variedad de compuestos fenólicos, alcaloides y terpenos. En este artículo se revisan los productos naturales activos frente a leishmaniasis, enfermedad del sueño y enfermedad de Chagas (AU)

Diseases caused by protozoan parasites are still an important human health problem, since many of them are becoming “emerging” infectious sickness in geographical areas where they were considered eradicated. Leishmaniasis, African sleeping sickness and Chagas disease, caused by the parasites Leishmania spp, Trypanosoma brucei and Trypanosoma cruzi, respectively, are among the most important parasitic diseases. The main alternative to control such parasitosis is chemotherapy. Nevertheless, the current drug treatments are far from being satisfactory. Toxic side effects, route of administration, long-term treatments and the apparition of resistance, highlight the urgent need of developing new active molecules, more safe and effective. Recent studies report the leishmanicidal and trypanocidal activities of a wide variety of phenolic compounds, alkaloids and terpenes that have shown activity in vivo. This review outlines the current understanding of natural products against leishmaniasis, African sleeping sickness and Chagas disease (AU)

Potencial anti-Leishmania e imunomodulador dos extratos de Campsiandra laurifolia Benth. (Fabaceae) / Anti-Leishmania and immunomodulatory potential of extracts of Campsiandra laurifolia Benth. (Fabaceae)

Infusões das folhas, cascas e sementes de Campsiandra laurifolia Benth. (Fabaceae) são utilizadas por comunidade de negros descendentes de escravos (quilombolas) para o tratamento, principalmente, de leishmaniose cutânea (LC), feridas, úlceras e impigens. Extratos hidroalcóolicos e aquosos de C. laurifolia foram investigados para a atividade anti-Leishmania sobre promastigotas e amastigota de Leishmania (L.) amazonensis e resposta imunomoduladora: proliferação celular de esplenócitos e produção ON por macrófagos peritoniais de camundongos BALB/c. Os extratos hidroalcóolicos da casca e aquosos da folha e semente apresentaram reduzida atividade contra as formas amastigotas e promastigotas (<20 por cento) e o mesmo foi observado para a inibição da produção de ON por macrófagos ativados (<23 por cento). A maioria dos extratos revelou moderado potencial imunossupressor (32,6 por cento a 38,5 por cento), mas os extratos aquosos da semente (AS) inibiram em até 87 por cento o crescimento de esplenócitos de BALB/c estimulados com mitógenos. Tal atividade talvez explique a indicação quilombola de C. laurifolia para o tratamento de LC, pois o seu uso pode não estar associado majoritariamente com uma ação direta sobre o parasito, mas sim com uma atividade anti-inflamatória, de vez que, tal atividade diminui os danos teciduais causados pelo sistema imune em resposta à infecção e, consequentemente, ajuda na cicatrização das lesões leishmanióticas.

Infusions of leaves, bark and seeds of Campsiandra laurifolia Benth. (Fabaceae) are used by communities of African-American descendants of slaves (quilombolas) mainly for treatment of cutaneous Leishmaniasis (CL), wounds, ulcers and tinea. Hydroalcoholic and aqueous extracts of C. laurifolia were investigated for anti-Leishmania activity on promastigotes and amastigotes of Leishmania (L.) amazonensis and immunomodulatory responses, including cell proliferation of splenocytes and NO production by peritoneal macrophages from BALB/c mice. The hydroalcoholic extracts of the bark and the aqueous extracts of the leaves and seeds presented a reduced activity against amastigotes and promastigotes (<20 percent), and the same result was observed for the inhibition of NO production by activated macrophages (<23 percent). Most of the extracts displayed a moderate immunosuppressive potential (32.6 to 38.5 percent); on the other hand, the aqueous extracts of seeds inhibited up to 87 percent of the growth of splenocytes of BALB/c mice stimulated with mitogens. Such activity may explain the use of C. laurifolia for the treatment of CL by quilombolas. Its use may not be mainly associated with a direct action on the parasite but with an anti-inflammatory activity because such activity decreases the tissue damage caused by the immune system in response to the infection and, consequently, aids the healing process of Leishmanial lesions.

Actividad citotóxica y leishmanicida in vitro del aceite esencial de manzanilla (Matricaria chamomilla) / In vitro leishmanicidal and cytotoxic activities of Matricaria chamomilla essential oil

Este estudio describe la evaluación de las actividades citotóxica y leishmanicida del aceite esencial de Matricaria chamomilla, una planta conocida como “manzanilla” a la que se le atribuye una variedad de usos en la medicina tradicional. La actividad del aceite esencial se evaluó in vitro contra amastigotes axénicos de L. (V) braziliensis, a concentraciones menores o iguales que 250μg/ml, y amastigotes intracelulares de L. (V) braziliensis y L. (V) panamensis, a concentraciones menores o iguales que 30μg/ml. Por su parte, la actividad citotóxica se evaluó contra células mamíferas de la línea promonocítica humana U-937, a concentraciones por debajo de 1,0 mg/ml. El aceite esencial de manzanilla mostró ser activo contra amastigotes intracelulares de L. (V) panamensis y L. (V) braziliensis (CE50 de 2,87 y 10,30μg /ml, respectivamente). Aunque el aceite esencial de manzanilla también mostró ser potencialmente tóxico para las células mamíferas (CL50 de 30,21μg /ml), esta toxicidad fue similar a la mostrada por la Anfotericina B (CL50 de 31,39μg /ml). El aceite esencial de manzanilla no mostró actividad contra las formas axénicas de L. (V) braziliensis, demostrando la importancia del metabolismo del compuesto en el interior de la célula para que se produzca el metabolito activo contra el parásito. Estos resultados aportan bases para sugerir que el aceite esencial de manzanilla tiene potencial para el desarrollo de medicamentos contra Leishmania, el cual debe ser validado en estudios futuros in vivo en modelos animales.

This study describes the evaluation of cytotoxic and leishmanicidal activities for Matricaria chamomilla essential oil. M. chamomilla is a plant commonly named “manzanilla” that has many uses in traditional medicine. The activity of essential oil was evaluated in vitro against axenic amastigotes of L. (V) braziliensis at concentrations lower than or equal to 250μg/ml and intracellular amastigotes of L. (V) braziliensis and L. (V) panamensis at concentrations lower than or equal to 30μg/ml. On other hand, the cytotoxic activity was assessed against mammalian cells of the promonocytic human cell line U937 at concentrations below 1.0mg/ml. The essential oil of M. chamomilla showed activity against intracellular amastigotes of L. (V) panamensis and L. (V) braziliensis (EC50 of 2.87 and 10.30μg/ml, respectively). Although the essential oil of M. chamomilla also shown to be potentially toxic to mammalian cells LC50 of 30.21μg ml) this toxicity was similar to that shown by Amphotericin B (LC50 of 31.39μg/ml). This essential oil showed no activity against axenic forms of L. (V) braziliensis suggesting the importance of the compound metabolism inside cells to produce the metabolite that would be active against parasites. These results suggest that the essential oil of M. chamomilla has potential for development of drugs anti- Leishmania that must be validated in future studies in vivo using animal models.

Produtos naturais com potencial leishmanicida / Natural products with leishmanicide potential

A leishmaniose é uma parasitose causada porprotozoários do gênero Leishmania. É uma doença endêmica que abrange mais de 80 países, incluindo alguns do continente europeu e, principalmente, países sub-desenvolvidos ou em desenvolvimento. Nesta revisão discorre-se sobre as opções terapêuticas tradicionais e atuais, cuja atividade leishmanicida pode conduzirao desenvolvimento racional de novos fármacos. Ressaltando-se o uso de produtos naturais na pesquisa e tratamento de Leishmaniose (ex. quinolonas, chalconase extratos brutos).

Hyperbaric oxygen therapy reduces the size of Leishmania amazonensis-induced soft tissue lesions in mice.

In this study we determined whether exposing mice to hyperbaric oxygen (HBO) would alter various disease parameters of a susceptible mouse strain infected with Leishmania amazonensis. BALB/c mice exposed to HBO (100% O2 at a pressure of 2.5 ATA, 1h before parasite inoculation and subsequently for 20 days) showed significant delay in lesion development and reduction in lesion parasite burdens compared with HBO-unexposed mice. Circulating levels of interferon gamma (IFN-gamma) and tumor necrosis factor (TNF-alpha) were significantly elevated in HBO-exposed as compared to HBO-unexposed mice. Concanavalin A-stimulated lymph nodes cultures from HBO-exposed mice released significantly more IFN-gamma and less interleukin 10 (IL-10) than cultures from HBO-unexposed mice, consistent with a skewed Th1 response. These results demonstrate, for the first time, that HBO can play a pathogen control role during leishmaniasis. Further studies are needed to elucidate whether hyperoxia alone or increased atmospheric pressure alone can exert a similar effect.

[Popular conceptions regarding cutaneous leishmaniasis in Colombia and their applicability in control programs]. / Conceptos populares sobre la leishmaniasis cutánea en Colombia y su aplicabilidad en programas de control.

A study was carried out to obtain information on prevailing popular ideas and attitudes about cutaneous leishmaniasis and its treatment in an isolated endemic area on the Colombian Pacific Coast. Interviews were conducted with a representative sample of individuals from the community and with health agents. The formal survey covered 736 households, 332 of them in a rural area (where leishmaniasis is endemic) and 404 in the city of Buenaventura (where there is no transmission of the disease.) The results showed that cutaneous leishmaniasis is well known in the rural area. The people have names for it (ya-te-vi or bejuco), have an understanding of its etiology (although their interpretation differs from that accepted by the scientific community), and have developed methods for preventing and treating it. The popular understanding of the disease results in behavior directed toward its prophylaxis and treatment that shares many characteristics with Western medicinal practices. The traditional treatments should be taken into account in the application of measures to control the disease in that area.

Ultrasound-induced hyperthermia in the treatment of cutaneous leishmaniasis.

Local hyperthermia induced by ultrasound was delivered two or three times weekly to twenty-eight lesions of acute cutaneous leishmaniasis in eighteen patients. Twenty-two lesions (78.5 percent) in thirteen patients resolved completely five to ten weeks after the start of treatment. Our results are explained by the thermosensitivity of the parasite and its inability to survive at supranormal temperatures. Ultrasound hyperthermia was tolerated by most of the patients. The results of this study indicate that topical heat is safe and effective for the treatment of patients with acute cutaneous leishmaniasis.

Thermosensitivity patterns of Old vs. New World cutaneous strains of Leishmania growing within mouse peritoneal macrophages in vitro.

Infection of mouse peritoneal macrophages in vitro was used to examine the effect of elevated temperature on the intracellular replication of various strains of Leishmania. Of eight cutaneous strains examined, all grew optimally at 35 degrees C. At 37 degrees C the reduction in growth was most pronounced for the New World cutaneous strains, and at 39 degrees C three of four New World cutaneous strains were completely destroyed whereas all of the L. tropica strains survived and exhibited at least 100% growth after 3 days. The results of these in vitro studies correlate closely with the outcome of heat therapy on two patients with cutaneous disease, suggesting that, in general, cutaneous lesions due to L. tropica strains might be less responsive to heat therapy than lesions due to L. mexicana and related strains.