Claudia Maria Leal Bevilaqua

Anthelmintic activity of essential oil of Ocimum gratissimum Linn. and eugenol against Haemonchus contortus.

The ovicidal activity of the essential oil of Ocimum gratissimum Linn. (Labideae) and its main component eugenol was evaluated against Haemonchus contortus, gastrointestinal parasite of small ruminants. The oil and eugenol were diluted in Tween 20 (0.5%) at five different concentrations. In the egg hatch test, H. contortus eggs were obtained from feces of goats experimentally infected. At 0.50% concentration, the essential oil and eugenol showed a maximum eclodibility inhibition. These results suggest a possible utilization of the essential oil of O. gratissimum as an aid to the control of gastrointestinal helmintosis of small ruminants.

Chemical composition of Eucalyptus spp. essential oils and their insecticidal effects on Lutzomyia longipalpis.

The chemical composition of essential oils from three species of plants belonging to the Eucalyptus genus was determined and, their insecticidal effects on egg, larva and adult phases of Lutzomyia longipalpis were assessed. The insects were collected in the municipality of Sobral in the State of Ceará, Brazil. Five treatments with different concentrations were performed along with two negative controls, distilled water and Tween 80 (3%), and a positive control, cypermethrin (0.196mg/ml). The tests were carried out in plastic pots internally coated with sterile plaster and filled with a substrate made of rabbit feces and crushed cassava leaves. The eggs, larvae and adults were sprayed with the oils. The hatched larvae were counted for 10 consecutive days and observed until pupation. Insect mortality was observed after 24, 48 and 72h. E. staigeriana oil was the most effective on all three phases of the insect, followed by E. citriodora and E. globulus oils, respectively. The major constituents of the oils were Z-citral and alpha-citral (E. staigeriana), citronellal (E. citriodora) and 1,8-cineole (E. globulus). The Eucalyptus essential oils constitute alternative natural products for the control of L. longipalpis since the median effective concentration (EC(50)) values revealed relevant action as compared with other natural products, some of their chemical constituents are already known for their insecticidal activity and these oils are produced in commercial scale in Brazil.

Nematódeos resistentes a anti-helmíntico em rebanhos de ovinos e caprinos do estado do Ceará, Brasil

The control of gastrointestinal nematodes parasitism is made basically with anthelmintics. Control failure is the first sign of anthelmintic resistance development. The actual situation of anthelmintic resistance prevalence in commercial farms of sheep and goats in Brazil is unknown. The aim of this work was to estimate the occurrence of oxfendazole, levamisole and ivermectin resistance in sheep and goats from medio and baixo Jaguaribe region by faecal egg count reduction followed by coprocultures. The work involved 25 farms (16 sheep farms, 7 goat farms and one of sheep and goats). Data were analysed by RESO (1989). The prevalence of resistant nematodes to oxfendazole, levamisole and ivermectin was respectively 88%, 41% and 59% in sheep and 87.5%, 75% and 37.5%, in goats. Haemonchus was the most prevalent genus in the resistant population to all anthelmintics in sheep and goats, followed by Trichostrongylus and Oesophagostomum.

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.

Anthelmintic activity of Cocos nucifera L. against sheep gastrointestinal nematodes

The development of anthelmintic resistance has made the search for alternatives to control gastrointestinal nematodes of small ruminants imperative. Among these alternatives are several medicinal plants traditionally used as anthelmintics. This work evaluated the efficacy of Cocos nucifera fruit on sheep gastrointestinal parasites. The ethyl acetate extract obtained from the liquid of green coconut husk fiber (LGCHF) was submitted to in vitro and in vivo tests. The in vitro assay was based on egg hatching (EHT) and larval development tests (LDT) with Haemonchus contortus. The concentrations tested in the EHT were 0.31, 0.62, 1.25, 2.5 and 5 mg ml(-1), while in the LDT they were 5, 10, 20, 40 and 80 mg ml(-1). The in vivo assay was a controlled test. In this experiment, 18 sheep infected with gastrointestinal nematodes were divided into three groups (n=6), with the following doses administered: G1-400 mg kg(-1) LGCHF ethyl acetate extract, G2-0.2 mg kg(-1) moxidectin (Cydectin) and G3-3% DMSO. The worm burden was analyzed. The results of the in vitro and in vivo tests were submitted to ANOVA and analyzed by the Tukey and Kruskal-Wallis tests, respectively. The extract efficacy in the EHT and LDT, at the highest concentrations tested, was 100% on egg hatching and 99.77% on larval development. The parameters evaluated in the controlled test were not statistically different, showing that despite the significant results of the in vitro tests, the LGCHF ethyl acetate extract showed no activity against sheep gastrointestinal nematodes.

Activity of chitosan-encapsulated Eucalyptus staigeriana essential oil on Haemonchus contortus

Phytotherapy has been described as an alternative method for the control of gastrointestinal nematodes in small ruminants. Goal of the encapsulation of essential oils in biopolymer matrices is to optimize the biological effects of these oils. The aim of the present study was to evaluate the in vitro and in vivo anthelmintic activity of encapsulated Eucalyptus staigeriana essential oil (EncEs) on the eggs and larvae of Haemonchus contortus. Therefore, the egg hatching test (EHT), larval development test (LDT) and worm load evaluation were performed to evaluate Meriones unguiculatus experimentally infected with H. contortus. The chemical constituents of E. staigeriana essential oil (EsEO) and the in vitro oil release profile from the chitosan matrix at a pH of 1.2 and 7.0 were also characterized. EncEs and EsEO inhibited larval hatching by 97.19% and 99.96% at doses of 1.5 and 1.0 mg ml(-1), respectively. In the LDT, EncEs and EsEO induced a larvicidal effect greater than 95% at concentrations of 5.8 and 8 mg ml(-1), respectively. EncEs and EsEO decreased H. contortus load in M. unguiculatus by 40.51% and 46.44%, respectively. The major chemical constituents of EsEO were (+)-Limonene (72.9%), 1,8-Cineole (9.5%) and o-Cimene (4.6%). The release profile of EsEO was 30% in acid and 25% at neutral pH. The similar efficacy of EncEs and EsEO demonstrates that there was no optimization of anthelmintic action following the encapsulation process. Therefore, the use of new encapsulation matrices with controlled release in the pH of the abomasum should be investigated.

Anthelmintic activity of Lippia sidoides essential oil on sheep gastrointestinal nematodes

Medicinal plants have been investigated for their anthelmintic properties and shown to be effective against eggs and larvae of gastrointestinal nematodes. The aim of this study was to evaluate the efficacy of the Lippia sidoides essential oil (LsEO) on sheep gastrointestinal nematodes. Initially, 44 naturally infected sheep were divided and treated with 200 microg kg(-1) ivermectin and 230 and 283 mg kg(-1) LsEO, respectively, plus the control. Fecal samples were collected from each animal to determine epg at 7, 14 and 21 days after treatment. In another test, 21 sheep were distributed and treated with 200 microg kg(-1) ivermectin, 283 mg kg(-1) LsEO and the control, respectively. Seven days after treatment, they were euthanized and necropsied to count and identify the nematodes from the abomasum, small and large intestines. In the first test, the efficacy of 230 and 283 mg kg(-1) LsEO and ivermectin was 38%, 45.9% and 40.2%, respectively, 7 days after treatment, and 30%, 54% and 39.6%, respectively, 14 days after treatment. In the second experiment, the respective efficacy of 283 mg kg(-1) LsEO and ivermectin was 56.9% and 34.4% against Haemonchus spp., and 39.3% and 63.6% against Trichostrongylus spp.

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.

Effect of six tropical tanniferous plant extracts on larval exsheathment of Haemonchus contortus

Tanniferous plants represent a promising alternative for controlling gastrointestinal nematodes of small ruminants. This experiment evaluated the effects of extracts from the leaf and stem of Anadenanthera colubrina, Leucaena leucocephala and Mimosa tenuiflora on larval exsheathment of Haemonchus contortus in vitro and verified the role of tannins in this process. Third-stage larvae of H. contortus were incubated with extracts for 3 hours and were exposed to sodium hypochlorite solution. The extracts were tested at 300 μg.mL(-1) and accompanied by controls: phosphate buffer solution (PBS) and polyvinyl polypyrrolidone (PVPP). The larval exsheathment was evaluated for 60 minutes, and the results were subjected to the Kruskal-Wallis test (p < 0.05). The six extracts blocked larval exsheathment. After PVPP addition, a tannin inhibitor, the exsheathment percentage was similar to the PBS (p > 0.05), except for L. leucocephala and M. tenuiflora leaf extracts. However, pre-incubation with PVPP of these two extracts significantly changed larval exsheathment when compared to the non-treated extracts (p < 0.05). These results suggest that A. colubrina, L. leucocephala and M. tenuiflora could be useful in gastrointestinal nematode control and that tannins are probably the main compounds involved in the observed effects. However, in vivo and toxicological studies should be conducted.

Ethnoveterinary knowledge of the inhabitants of Marajó Island, Eastern Amazonia, Brazil

Em varias partes do mundo existem relatos etnoveterinarios sobre a utilizacao de plantas em protocolos terapeuticos, entretanto nao existem informacoes disponiveis sobre a etnoveterinaria praticada na Amazonia brasileira. Desta forma, objetivou-se documentar o conhecimento etnoveterinario de habitantes da Ilha do Marajo, Amazonia Oriental. Foram realizadas 50 entrevistas individuais com aplicacao de questionarios semi-estruturados que foram analisados quantitativamente atraves de estatistica descritiva utilizando frequencia de distribuicao. O valor de uso foi calculado para determinar as especies mais importantes. Amostras de plantas com relatos de uso medicinal foram coletadas e identificadas botanicamente. Cinquenta plantas, distribuidas em 48 generos e 34 familias, foram indicadas para 21 diferentes usos medicinais. A familia Asteraceae foi a que teve maior numero de especies citadas e Carapa guianensis Aubl, Crescentia cujete L., Copaifera martii Hayne, Caesalpinia ferrea Mart., Chenopodium ambrosioides L., Jatropha curcas L. e Momordica charantia L. foram as especies com maiores valor de uso. As partes das plantas mais utilizadas para preparo dos medicamentos etnoveterinarios foram folhas (56%), cascas (18%), raizes (14%), sementes (14%) e frutos (8%). Quanto a forma de uso o cha foi citado por 56% dos entrevistados e a maioria das preparacoes (90,9%) utiliza uma so planta. Alem das plantas medicinais, os entrevistados relataram o uso de produtos de origem animal e mineral. Esse trabalho contribui para realizacao de um inventario das plantas utilizadas na etnoveterinaria marajoara que pode servir de base de dados para futuros estudos de validacao cientifica.