In vitro effect of Aloe vera, Coriandrum sativum and Ricinus communis fractions on Leishmania infantum and on murine monocytic cells.

In South America, visceral leishmaniasis is a zoonosis caused by the protozoan species Leishmania infantum (syn. L. chagasi) and is primarily transmitted through the bite of the female Lutzomyia longipalpis. Its main reservoir in urban areas is the dog. The application of control measures recommended by health agencies have not achieved significant results in reducing the incidence of human cases, and the lack of effective drugs to treat dogs resulted in the prohibition of this course of action in Brazil. Therefore, it is necessary to search new alternatives for the treatment of canine and human visceral leishmaniasis. The objectives of this study were to evaluate the in vitro effect of fractions from Aloe vera (aloe), Coriandrum sativum (coriander), and Ricinus communis (castor) on promastigotes and amastigotes of L. infantum and to analyze the toxicity against the murine monocytic cells RAW 264.7. To determine the viability of these substances on 50% parasites (IC50), we used a tetrazolium dye (MTT) colorimetric assay (bromide 3-4.5-dimethylthiazol-2-yl-2,5-dephenyltetrazolium), and on amastigotes we performed an in situ ELISA. All fractions were effective against L. infantum promastigotes and did not differ from the positive control pentamidine (p>0.05). However, the R. communis ethyl acetate and chloroform fractions, as well as the C. sativum methanol fraction, were the most effective against amastigotes and did not differ from the positive control amphotericin B (p>0.05). The R. communis ethyl acetate fraction was the least toxic, presenting 83.5% viability of RAW 264.7 cells, which was similar to the results obtained with amphotericin B (p>0.05). Based on these results, we intend to undertake in vivo studies with R. communis ethyl acetate fractions due the high effectiveness against amastigotes and promastigotes of L. infantum and the low cytotoxicity towards murine monocytic cells.

Anthelmintic effect of Eucalyptus staigeriana essential oil against goat gastrointestinal nematodes.

The aim of this study was to evaluate the anthelmintic efficacy of Eucalyptus staigeriana essential oil (EsEO). The in vitro effects of EsEO were determined through the egg hatching test and the inhibition of larval development of Haemonchus contortus. The oil was subjected to acute and subacute toxicity rodents. The in vivo effects were determined through fecal egg count reduction test in goats. 1.35 and 5.4 mgml(-1) EsEO inhibited 99.27 and 99.20% H. contortus egg hatching and larval development. In subacute toxicity of EsEO, all parameters were found to be in the normal range, and histopathological analysis of organs did not present alterations. EsEO efficacy against goat gastrointestinal nematodes was 76.57% at 15th day after treatment. E. staigeriana essential oil showed in vitro and in vivo anthelmintic activity.

[Ovicidal and larvicidal activity in vitro of Eucalyptus globulus essential oils on Haemonchus contortus]. / Atividade ovicida e larvicida in vitro do óleo essencial de Eucalyptus globulus sobre Haemonchus contortus.

The objective of this work was to evaluate ovicidal and larvicidal effects of Eucalyptus globulus essential oil (EGEO) on Haemonchus contortus. The chemical composition determination of EGEO was through gas chromatography and mass spectrometry. Egg hatch test (EHT) was performed in concentrations 21.75; 17.4; 8.7; 5.43 e 2.71 mg x mL(-1). In larval development test (LDT) were used the concentrations 43.5; 21.75; 10.87; 5.43 e 2.71 mg x mL(-1). Each trial was conducted by negative control with Tween 80 (3%) and positive control, 0.02 mg x mL(-1) of thiabendazole in EHT and 0.008 mg x mL(-1) of ivermectin in LDT. The maximum effectiveness of EGEO on eggs was 99.3% in concentration of 21.75 mg x mL(-1) and on larvae was 98.7% in concentration 43.5 mg x mL(-1). The concentration of EGEO that inhibits 50% of the eggs and larvae was 8.3 and 6.92 mg x mL(-1), respectively. The oil chemical analysis identified as main component the monoterpen 1,8-cineol. EGEO presented ovicidal and larvicidal activities in vitro, revealing a good potential for use in the control of sheep and goat gastrointestinal nematodes.

Atividade ovicida e larvicida in vitro do óleo essencial de Eucalyptus globulus sobre Haemonchus contortus / Ovicidal and larvicidal activity in vitro of Eucalyptus globulus essential oils on Haemonchus contortus

O objetivo deste trabalho foi avaliar o efeito do óleo essencial de Eucalyptus globulus (OEEG) sobre a eclosão e desenvolvimento de larvas de Haemonchus contortus. A determinação da composição química do OEEG foi feita por meio de cromatografia gasosa acoplada à espectrometria de massa. No teste de eclosão de ovos (TEO), utilizaram-se as concentrações 21,75; 17,4; 8,7; 5,43 e 2,71 mg.mL-1; e no de desenvolvimento larvar (TDL) as concentrações foram 43,5; 21,75; 10,87; 5,43 e 2,71 mg.mL-1. Cada ensaio foi acompanhado por um controle positivo, 0,02 mg.mL-1 tiabendazol, no TEO e 0,008 mg.mL-1 ivermectina no TDL, e por um controle negativo com o diluente Tween 80 (3 por cento). A eficácia máxima obtida pelo OEEG sobre ovos foi de 99,3 por cento na concentração de 21,75 mg.mL-1 e, sobre larvas, 98,7 por cento na concentração de 43,5 mg.mL-1. A concentração do OEEG, que inviabilizou 50 por cento dos ovos e das larvas do parasito, foi de 8,3 e 6,92 mg.mL-1, respectivamente. A análise química do óleo identificou como principal componente o monoterpeno 1,8-cineol. O OEEG apresentou atividade ovicida e larvicida in vitro sobre H. contortus, determinando um bom potencial para utilização no controle de nematóides gastrintestinais de ovinos e caprinos.

The objective of this work was to evaluate ovicidal and larvicidal effects of Eucalyptus globulus essential oil (EGEO) on Haemonchus contortus. The chemical composition determination of EGEO was through gas chromatography and mass spectrometry. Egg hatch test (EHT) was performed in concentrations 21.75; 17.4; 8.7; 5.43 e 2.71 mg.mL-1. In larval development test (LDT) were used the concentrations 43.5; 21.75; 10.87; 5.43 e 2.71 mg.mL-1. Each trial was conducted by negative control with Tween 80 (3 percent) and positive control, 0.02 mg.mL -1 of thiabendazole in EHT and 0.008 mg.mL-1 of ivermectin in LDT. The maximum effectiveness of EGEO on eggs was 99.3 percent in concentration of 21.75 mg.mL-1 and on larvae was 98.7 percent in concentration 43.5 mg.mL-1. The concentration of EGEO that inhibits 50 percent of the eggs and larvae was 8.3 and 6.92 mg.mL-1, respectively. The oil chemical analysis identified as main component the monoterpen 1,8-cineol. EGEO presented ovicidal and larvicidal activities in vitro, revealing a good potential for use in the control of sheep and goat gastrointestinal nematodes.