Morphological alterations of Thymus during the early murine leishmaniasis.

Leishmaniasis is a neglected and endemic disease that affects poorest population mainly in developing countries. Thymus provides an essential complex environment for T cell maturation and differentiation during leishmania infection. The aim of this study was to investigate the pathological alterations of the Thymus during early Leishmania amazonensis murine infection. BALB/c mice were infected with 105 amastigotes for 24 h, 3 days, 7 days, 15 days or 30 days. At different times of infection, the relative weight of the Thymus was obtained, and the Thymus cellularity was determined by counting total cells of one thymic lobe. The thymic lobe was, alternatively, processed for standard Haematoxylin and Eosin protocol. Our results suggest thymic alteration during the early days of BALB/c mice infection with L. amazonensis. The thymic hypertrophy was accompanied by histological alterations in Thymus architecture with thickening cortex at 3 days p.i. and loss of an evident delimitation between the cortex and medulla at 7 days p.i. when compared to the control mice. That is the first time that Thymus hypertrophy was observed during the early leishmaniasis. However, how it may contribute to infection susceptibility requires further investigation.

Preliminary phytochemical and antileishmanial studies of the ethanolic extracts of Pterodon pudescens / Estudos preliminares sobre a fitoquimica e a atividade anti-leishmania de extratos etanólicos de Pterodon pudescens

Pentavalent antimonials are the first choice for the treatment of human leishmaniasis. However in rural areas the traditional plants may be preferred for the treatment of lesions. In recent years a number of papers are published related to the natural products especially plant derivative with infectious diseases. The present work was undertaken to evaluate the antileishmanial activity of Pterodon pubescens which is a native tree widely distributed over the central region of Brazil and used in folk medicine as wine infusions to treat inflammatory disease. The phytochemical screening and the biological essay of ethanolic extract of Pterodon pudescens (PPE) leaves at the concentrations of 150, 300, 450, 600 µg/ml were tested in vitro in Leishmania amazonensis-infected macrophages to support its traditional medicinal use as a leishmaniasis remedy. Phytochemical screening of PPE has shown the presence of catechemical tannins, steroids, triterpenoids and flavonoids. The biological test suggests that PPE were found to control parasite burden of cell cultures in dose-dependent manner. These findings highlight the fact that the apparent potency of Pterodon pudescens compounds, together with their widely distribution over Latin America and Brazil, may represent a promising antileishmanial agent.

Antimoniais pentavalentes são a primeira escolha para o tratamento das leishmanioses humanas. No entanto, no interior brasileiro plantas tradicionais são usadas para o tratamento dessas lesões. De fato, recentes trabalhos tem relatado o potencial terapêutico de produtos naturais, especialmente derivados de plantas. Neste estudo avaliamos a atividade leishmanicida de Pterodon pubescens, uma árvore nativa, distribuída pela região central brasileira e usada em infusões para tratamento de inflamações. Foi realizada a análise fitoquímica e o ensaio in vitro em macrófagos infectados com Leishmania amazonensis em concentrações de 150, 300, 450, 600 µg/ml do extrato etanólico de folhas de Pterodon pudescens (PPE) para comprovar o uso tradicional desta planta como terapia para as leishmanioses. Os testes fitoquímicos indicaram a presença de taninos catequímicos, flavonas, esteroides, triterpenoides, flavonoides e xantonas. Os ensaios biológicos revelaram que o PPE foi capaz de controlar a carga parasitária em macrófagos de maneira dose dependente. Estes resultados corroboram com o potencial terapêutico de compostos de Pterodon pudescens e, junto com sua ampla distribuição no Brasil, podem representar promissor agente leishmanicida.

The influence of low oxygen on macrophage response to Leishmania infection.

Hypoxia (low oxygen tension) is a common feature of inflamed and infected tissues. The influence of hypoxia on macrophage responses to micro-organisms has only recently been studied. This study demonstrates that hypoxia induced macrophages to control Leishmania amazonensis, an intracellular parasite that causes cutaneous and cutaneous metastatic lesions. The mechanisms that contribute to the control of macrophages against L. amazonensis infection under a hypoxic microenvironment are not known. Nitric oxide, TNF-α, IL-10 or IL-12 is not responsible for the decrease in parasitism under hypoxia. Live L. amazonensis entry or exocytosis of internalized particles as well as energetic metabolism was not impaired in infected macrophages; no apoptosis-like death was detected in intracellular parasites. Reactive oxygen species (ROS) is likely to be involved, because treatment with antioxidants N-acetylcysteine (NAC) and ebselen inhibits the leishmanicidal effect of macrophages under hypoxia. Leishmania amazonensis infection induces macrophages to express hypoxia-inducible factor-1 (HIF-1α) and -2 (HIF-2α). Data indicate that hypoxia affects the microbial activities and protein expression of macrophages leading to a different phenotype from that of the normoxic counterpart and that it plays a role in modulating Leishmania infection.

Avaliação da eficácia de taboa (Typha domingensis Pers.) e batata-de-purga [Operculina hamiltonii (G. Don) D.F. Austin & Staples] in natura sobre nematóides gastrintestinais de caprinos, naturalmente infectados, em clima semi-árido / Evaluation of the effectiveness of "taboa" (Typha domingensis Pers.) and "batata-de-purga" [Operculina hamiltonii (G. Don) D.F. Austin & Staples] in natura on gastrointestinal nematodes of goats, naturally infected, in the semi-arid region

Avaliou-se a eficácia da Typha domingensis (taboa) e da Operculina hamiltonii (batata-de-purga) in natura sobre nematóides gastrintestinais de caprinos, naturalmente infectados, em clima semi-árido. Foram utilizados 30 caprinos da raça Moxotó, e o rizoma da taboa e a raiz da batata-de-purga, avaliados através da fitoquímica. As fezes foram coletadas nos dias zero, sete e 25, após, o tratamento da contagem de OPG. Os animais foram distribuídos inteiramente ao acaso, com cinco tratamentos e seis repetições. Grupo I tratado com Moxidectina 0,2 por cento em dose única de 0,5 mg Kg-1; o Grupo II tratado com Taboa na dose (10 g 20 Kg-1 peso vivo); Grupo III com batata-de-purga na dose de 9 g 20 Kg-1 p.v.; Grupo IV tratado com taboa 10 g 20 Kg-1 p.v. associada a batata 9 g 20 Kg-1 p.v. durante três dias consecutivos, todos administrados oralmente e o Grupo V como grupo controle. Os grupos tratados apresentaram redução no número médio de OPG aos 7 e 25 dias pós-tratamento, quando comparado com o grupo controle no respectivo período, sendo a batata-de-purga com maior redução aos 7 e a taboa aos 25 dias. A maior eficácia foi da batata-de-purga de 84 por cento e 70 por cento, nos dias 7 e 25 pós-tratamento. Verificou-se que a batata-de-purga foi eficaz no controle de nematóides gastrintestinais de caprinos no clima semi-árido e que a taboa associada com a batata tem potencial para serem utilizadas em programas alternativos de controle parasitário.

The effectiveness of Typha domingensis ("taboa") and Operculina hamiltonii ("batata-de-purga") in natura was evaluated on gastrointestinal nematodes of goats, naturally infected, in the semi-arid region. Thirty Moxotó goats were used, and the rhizome of "taboa" and the root of "batata-de-purga" were analyzed through phytochemistry. Feces were collected on days zero, seven and 25 after the treatment for FECs. The distribution of animals was completely at random, with five treatments and six replicates. Group I was treated with Moxidectin 0.2 percent in a single dose of 0.5 mg kg-1; Group II was treated with "taboa" at the dose of 10 g 20 Kg-1 body weight; Group III was treated with "batata-de-purga" at the dose of 9 g 20 Kg-1 b.w.; Group IV was treated with "taboa" at 10 g 20 Kg-1 b.w. associated with "batata-de-purga" at 9 g 20 Kg-1 b.w. during three consecutive days. All treatments were orally administered and Group V was used as control. Treated groups showed a reduction in the average number of FECs at seven and 25 days post-treatment when compared to the control group in the respective period; "batata de purga" had a greater reduction at seven days, while "taboa" showed a more pronounced reduction at 25 days. The highest effectiveness was observed for "batata de purga": 84 percent and 70 percent at seven and 25 days post treatment. "Batata-de-purga" was effective in controlling gastrointestinal nematodes of goats in the semi-arid climate and "taboa" associated with "batata de purga" have the potential to be used in alternative programs for parasite control.

Natural evolution of gastrointestinal nematodes in goats (Capra hircus) in the semi-arid ecosystem of the Paraíba backwoods, northeastern Brazil.

This study was conducted in Patos county, a semi-arid area with caatinga vegetation in Paraiba State, northeastern Brazil. Twenty-four male goats of mixed breeds were used. The animals were separated in age groups from 1-12 months, i. e., 1-2, 3-4, 5-6, 7-8, 9-10, 11-12 months, with four animals in each group. The animals were slaughtered and necropsied to recover and identify adult worms. The goats were exposed to nematode infection from the first month of life. The most prevalent nematodes in decreasing order were: Trichostrongylus colubriformis, Haemonchus contortus and Oesophagostomum columbianum. Age of the goats did not appear to be a factor in resistance to gastrointestinal nematode infection. Worm burdens of 11-12 month old animals were significantly (P<0.05) higher than in other age groups.