In vitro efficacy of isoflavonoids and terpenes against Leishmania (Leishmania) infantum and L. amazonensis.

The main form of control of leishmaniasis is the treatment, however various side effects and poor efficacy are associated with presently available drugs. The investigation of bioactive natural products for new antileishmanial drugs is a valid approach. The present study reports the in vitro efficacy of natural isoflavonoids and terpenes against Leishmania infantum and L. amazonensis and their cytotoxicity against HepG2 cells. L. infantum and L. amazonensis promastigotes were exposed to the terpenes kaurenoic acid, xylopic acid, and (-)-α-bisabolol and to the isoflavonoids (-)-duartin and (3R)-claussequinone for antileishmanial activity and to cytotoxicity to HepG2 cells. The most effective substance against both L. infantum and L. amazonensis species was (3R)-claussequinone (IC50 = 3.21 µg/mL and 2.47 µg/mL, respectively) that disclosed low cytotoxicity against HepG2 cells (CC50 = 387.79 µg/mL). The efficacy of (3R)-claussequinone against intracellular amastigotes of L. infantum and the externalization of phosphatidylserine in promastigotes of this isoflavanoid were investigated by infection of Raw 264.7 macrophages and marking with Annexin V-FITC and propidium Iodide for flow cytometry analysis. The results for amastigotes showed that (3R)-claussequinone was able to reduce the rate of infection with IC50 = 4.61 µg/mL and did not alter the externalization of phosphatidylserine. In conclusion it is presently reported, for the first time, the striking antileishmanial activity of (3R)-claussequinone against L. infantum and L. amazonensis associated to low cytotoxicity. Furthermore, these results suggest that (3R)-claussequinone is a new hit aiming to develop new therapeutic alternatives.

Efficacy of lapachol on treatment of cutaneous and visceral leishmaniasis.

Leishmaniasis is one of the most important neglected diseases worldwide. It is a life-threatening disease and causes significant morbidity, long-term disability, and early death. Treatment involves disease control or use of intervention measures, although the currently used drugs require long-lasting therapy, and display toxicity and reduced efficacy. The use of natural products isolated from plants, such as lapachol, an abundant naphthoquinone naturally occurring in South American Handroanthus species (Tabebuia, Bignoniaceae), is a promising option for the treatment of leishmaniasis. In this study, we investigated the leishmanicidal activity of lapachol in vitro and in vivo against Leishmania infantum and L. amazonensis, causative agents of visceral and cutaneous leishmaniasis, respectively. Low cytotoxicity in HepG2 cells (3405.8 ±â€¯261.33 µM), good anti-Leishmania activity, and favorable selectivity indexes (SI) against promastigotes of both L. amazonensis (IC50 = 79.84 ±â€¯9.10 µM, SI = 42.65) and L. infantum (IC50 = 135.79 ±â€¯33.04 µM, SI = 25.08) were observed. Furthermore, anti-Leishmania activity assays performed on intracellular amastigotes showed good activity for lapachol (IC50 = 191.95 µM for L. amazonensis and 171.26 µM for L. infantum). Flow cytometric analysis demonstrated that the cytotoxic effect of lapachol in Leishmania promastigotes was caused by apoptosis-like death. Interestingly, the in vitro leishmanicidal effect of lapachol was confirmed in vivo in murine models of visceral and cutaneous leishmaniasis, as lapachol (25 mg/kg oral route for 24 h over 10 days) was able to significantly reduce the parasitic load in skin lesions, liver, and spleen, similar to amphotericin B, the reference drug. These results reinforce the therapeutic potential of lapachol, which warrants further investigations as an anti-leishmaniasis therapeutic.

Preparing Collared Peccary (Pecari tajacu Linnaeus, 1758) for Reintroduction into the Wild: A Screening for Parasites and Hemopathogens of a Captive Population.

The reintroduction of captive animals to the wild helps restore endangered species, but it risks pathogen transmission, harming wild populations. Such transmission can impact the genetic diversity and long-term viability of these populations. This study assessed parasite diversity and load in captive Pecari tajacu, a species native to the Americas and culturally significant to Brazilian indigenous culture, prior to reintroduction. Samples from 24 peccaries were analyzed for ectoparasites, hemopathogens, and stool parasites with direct and molecular analysis. Findings showed that various parasites were present. Two peccaries (8.3%) were infested by the adult tick Amblyomma sculptum. Six (25.0%) tested positive for Trypanosoma evansi, four (16.7%) for hemobacteria of the family Anaplasmataceae, twelve (50.0%) for hemotropic Mycoplasma, and seven (29.2%) for Leishmania braziliensis. Stool samples indicated multiple parasites, with sixteen (66.7%) peccaries infected by Strongylida order parasites, Spiruridae in three (12.5%), and Ascaris suum in one (4.2%) animal. Cysts of Balantidium sp. were found in twenty (83.3%), Entamoeba polecki in five (20.8%), and Iodamoeba bütschlii in two (8.3%) peccaries. To our current knowledge, this is the first global report of Leishmania braziliensis, Iodamoeba bütschlii, and Entamoeba polecki in P. tajacu, irrespective of the environment, including both captivity and wild conditions. Some of these parasites are common in domestic animals, and others are zoonotic, indicating potential interspecies pathogen transmission.

Conhecer para prevenir: complementação do conhecimento dos alunos do ensino fundamental sobre microbiologia e parasitologia em três escolas de Uberlândia-MG / Know to prevent: complementation of the knowledge of the students of fundamental education on microbiology and parasitology in three schools of Uberlândia-MG

O conhecimento sobre microbiologia e parasitologia é considerado abstrato, pois muitos agentes causadores de doenças não são vistos a olho nu, o que distancia os alunos da realidade. Assim, nossos objetivos foram promover ações educativas por meio de ferramentas didáticas lúdicas que possibilitassem a complementação do aprendizado dos alunos frente aos diferentes grupos de microorganismos e parasitos e das ações de profilaxia relacionadas aos mesmos, e avaliar se ao final eles tinham condições de discriminar os grupos e relacionar com as doenças e as formas de profilaxia. Para tanto, foram feitas entrevistas junto aos professores para levantamento das possíveis atividades a serem desenvolvidas. A ação foi definida e então dividida em três momentos (aula expositiva, jogo didático e mostra científica) realizados entre agosto e novembro de 2018, atingindo aproximadamente 350 alunos, de oitavos e nonos anos, de três escolas públicas da zona urbana e rural da cidade de Uberlândia-MG. Para avaliar o impacto da ação foi feita uma análise comparativa de questionários aplicados antes (pré-intervenção) e após a ação (pós-intervenção). O percentual das respostas corretas nos questionários pós-intervenção aumentou em duas escolas (p>0,005). Quanto à análise por questões, as menores porcentagens de acertos foram observadas em perguntas relacionadas à distinção entre doenças bacterianas e virais, o reconhecimento dos sintomas e a associação das formas de transmissão com a profilaxia. Assim, este estudo reforça a importância da educação em saúde para que os alunos se mobilizem frente ao combate das doenças.(AU)

The knowledge about microbiology and parasitology is considered abstract since causative agents of diseases cannot be seen with the naked eye, leading to students' detachment from reality. Therefore, this work aimed to promote educational actions through playful tools that could complement students' learning regarding the different groups of microorganisms and parasites and the prophylactic measures related to them. Furthermore, at the end of the actions it was evaluated if the students were able to discriminate the groups of microorganisms and relate them to the diseases they cause and the different forms of prophylaxis. To this end, interviews were conducted with teachers to survey the possible activities that could be used. The action was defined and then divided into three moments (expository class, didactic game and scientific show) held between August and November 2018, reaching approximately 350 students, from the eighth and ninth years, from three public schools in the urban and rural area of the city oftUberlândia-MG. To assess the impact of the action, a comparative analysis of questionnaires was applied before (pre-intervention) and after the action (post-intervention). The percentage of correct answers in the questionnaires post-intervention increased in two schools (p>0,005). Regarding the analysis by questions, the lowest percentages of correct answers were observed in questions related to the distinction between bacterial and viral diseases, the recognition of the symptoms and the association of transmission ways with prophylaxis. Thus, this study reinforces the importance of health education for students to mobilize in the fight against diseases.(AU)