ABSTRACT
BACKGROUND Leishmaniasis, a neglected disease caused by the parasite Leishmania, is treated with drugs associated with high toxicity and limited efficacy, in addition to constant reports of the emergence of resistant parasites. In this context, snake serums emerge as good candidates since they are natural sources with the potential to yield novel drugs. OBJECTIVES We aimed to show the antileishmanial effects of γCdcPLI, a phospholipase A2 inhibitor from Crotalus durissus collilineatus snake serum, against Leishmania (Leishmania) amazonensis. METHODS Promastigotes forms were exposed to γCdcPLI, and we assessed the parasite viability and cell cycle, as well as invasion and proliferation assays. FINDINGS Despite the low cytotoxicity effect on macrophages, our data indicate that γCdcPLI has a direct effect on parasites promoting an arrest in the G1 phase and reduction in the G2/M phase at the highest dose tested. Moreover, this PLA2 inhibitor reduced the parasite infectivity when promastigotes were pre-treated. Also, we demonstrated that the γCdcPLI treatment modulated the host cell environment impairing early and late steps of the parasitism. MAIN CONCLUSIONS γCdcPLI is an interesting tool for the discovery of new essential targets on the parasite, as well as an alternative compound to improve the effectiveness of the leishmaniasis treatment.
ABSTRACT
BACKGROUND Leishmania parasites cause leishmaniasis that range from self-limiting cutaneous lesions to more serious forms of the disease. The search for potential drug targets focusing on biochemical and metabolic pathways revealed the sterol biosynthesis inhibitors (SBIs) as a promising approach. In this class of inhibitors is found ketoconazole, a classical inhibitor of 14α-methysterol 14-demethylase. OBJECTIVE The present study aimed to better understand the biological response of Leishmania (Leishmania) amazonensis promastigotes at the cellular level after ketoconazole treatment. METHODS Herein, techniques, such as fluorimetry, flow cytometry, fluorescence microscopy, electron and scanning microscopy were used to investigate the cellular structures and to identify organelles affected by ketoconazole treatment. FINDINGS The study demonstrated, for the first time, the effect of ketoconazole on mitochondrion functioning and its probable relationship to cell cycle and death on L. (L.) amazonensis promastigotes (IFLA/BR/67/PH8 strain). MAIN CONCLUSIONS Ketoconazole-induced mitochondrial damages led to hyperpolarisation of this single organelle and autophagic vacuoles formation, as a parasite survival strategy. These damages did not reflect directly on the parasite cell cycle, but drove the parasites to death, making them susceptible to ketoconazole treatment in in vitro models.
ABSTRACT
A avaliação da fertilidade de um touro é realizada considerando diferentes aspectos do animal e de seu sêmen. O objetivo deste estudo foi conhecer o perfil bioquímico de proteínas e açúcares redutores do plasma seminal em touros da raça Nelore com 24 meses de idade e sua relação com as características do sêmen. Foram utilizados 20 animais e as amostras de sêmen foram coletadas pelo método de eletroejaculação. As dosagens de proteínas e de açúcares redutores foram determinadas pelos métodos de Bradford com modificações e de Miller (ácido 3-5 dinitrosalicílico), respectivamente. A concentração de proteínas no plasma seminal variou de 5,90 a 166,33 mg/mL, com média de 61,41±44,60 mg/mL e a concentração de açúcares redutores variou de 0,78 a 19,88 mg/mL, com média de 9,31±4,54 mg/mL. A correlação entre a concentração de proteínas e açúcares redutores foi significativa com r = 0,88 (p<0,05), sendo também significativa entre elas e a concentração e patologia espermáticas. O perfil de proteínas e açúcares redutores do plasma seminal de touros da raça Nelore com 24 meses de idade apresentou variação entre os animais, o que demonstra que a produção destes elementos tem característica individual e são importantes para a qualidade do sêmen.
The fertility evaluation of a bull is accomplished considering different aspects of the animal and its semen. The objective of this study was to know the biochemical profile of proteins and reducing sugars in the seminal plasma of within 24-month Nelore bulls and its relation to semen characteristics. Twenty animals were used and their semen samples were collected using electrical ejaculation. The dosages of proteins and reducing sugars were determined by the Bradford method with modifications and Miller (3-5 dinitrosalycilic acid), respectively. It was obtained in the concentration of proteins in the seminal plasma range from 5.90 to 166.33 mg/mL, average of 61,41±44,60 mg/mL and in the concentration of reducing sugars ranging from 0.78 to 19.88 mg/mL, average 9,31±4,54 mg/mL. The correlation between protein and sugar concentrations was significant with r= 0.88 (p <0.05). This correlation was also significant with concentration and spermatic pathology. The biochemical profile of proteins and reducing sugars in seminal plasma of with 24-month Nelore bulls showed a variation among the animals, demonstrating that the production of these elements is an individual characteristic and has great importance in the semen quality
Subject(s)
Reproduction , Semen , Cattle , FertilityABSTRACT
American cutaneous leishmaniasis (ACL) is an endemic disease caused by Leishmania parasites. The ACL diagnosis is commonly accomplished by parasitological and immunological methods. The objective of this work was to evaluate the enzyme immunoassay (EIA) for ACL laboratorial diagnosis. IgG antibodies against Leishmania (Viannia) braziliensis promastigotes were researched. For the method standardization 240 sera were used: 72 from patients with positive parasitological diagnosis, 38 from normal individuals and 113 from individuals with other pathologies. The sensibility was 93 percent and the specificity was 70 percent. Regarding diagnosis, EIA showed 97 percent positivity in patients with ACL and 97 percent negativity in patients with other cutaneous lesions. The EIA presented a good performance when used for diagnosis, thus, it may become an important tool for it and for further ACL epidemiological studies in endemic areas.
Subject(s)
Adolescent , Adult , Aged , Aged, 80 and over , Animals , Child , Female , Humans , Male , Middle Aged , Antibodies, Protozoan/blood , Immunoglobulin G/blood , Leishmania braziliensis/immunology , Leishmaniasis, Cutaneous/diagnosis , Brazil , Case-Control Studies , Endemic Diseases , Immunoenzyme Techniques , Predictive Value of Tests , Sensitivity and Specificity , Skin TestsABSTRACT
A elucidação estrutural de glicoconjugados de superfície de Leishmania é um tema de grande relevância uma vez que estes componentes mostram-se envolvidos em diversos processos na interação do parasita com a célula hospedeira. Desse modo, seis frações glicolipídicas, denominadas de B1 a B6, foram purificadas de promastigotas de L. (v. ) braziliensis por cromatografia líquida de alta resolução (HPLC) . Todas as frações foram lábeis à hidrólise alcalina suave e as análises por cromatografia gasosa acoplada a espectrometria de massa (GC/MS) demonstraram a presença de manose, galactose, glucose, glucosamina e myo-inositol, sugerindo que os glicolipídeos sejam glicoinositolfosfolipídeos (GIPLs) . A análise dos alditóis acetato parcialmente metilados (PMAAs) mostrou a presença de 2,4 -di -O-metil-mani tol tetracetato, sugerindo uma estrutura glicana ramificada contendo resíduo de galactose terminal, decorrente da presença de 2,3,4,6-tetra-O-metil galactitol diacetato entre os PMAAs . A reatividade com o anticorpo monoclonal (mAb) 8T-3 também sugere a presença de resíduos de Galb1-+3Galcx na porção glicana dos GIPLs. Estes resultados indicam que promastigotas de L. (v. ) braziliensis expressam GIPLs, os quais possivelmente possam ser incluídos nos GIPLs tipo híbrido apresentando, entretanto, novas estruturas glicanas...