The anthelmintic effect of plant extracts on Haemonchus contortus and Strongyloides venezuelensis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

In vitro Anthelmintic effect of Melia azedarach L. and Triclinia claussenii C. against sheep gastrointestinal nematodes

The control of parasitic diseases in small ruminants is mainly done with the use of synthetic anthelmintics. However, incorrect and indiscriminate use of these products has caused the emergence of parasite resistance. Plants with anthelmintic activity are used in folk veterinary medicine, but it is necessary to investigate and scientifically validate low-cost phytotherapeutic alternatives for future use to control gastrointestinal nematodes in small ruminants by family farmers. Thus, the aim of this study was to evaluate the in vitro anthelmintic effect of plant extracts from Melia azedarach and Trichilia claussenii by the egg hatch test (EHT) and larval development test (LDT) against sheep gastrointestinal nematodes. The hexane extract of M. azedarach fruits was extracted through cold percolation and the methanol extract of T. claussenii leaves was obtained by extraction at room temperature in solvents in order of increasing polarity. The efficacy results were analyzed using the Probit program of SAS. The M. azedarach extract showed a LC50 of 572.2 mu g/mL and LC99 of 1137.8 mu g/mL in the EHT, and LC50 of 0.7 mu g/mL and LC99 of 60.81 mu g/mL in the LDT. In turn, the T. claussenii extract presented a LC50 of 263.8 mu g/mL and LC99 of 522.5 mu g/mL in the EHTand LC50 of 1.11 mu g/mL and LC99 of 26.4 mu g/mL in the LDT. Comparing the extracts of the species from the Meliaceae family, T. claussenii showed greater anti-parasite potential in vitro than M. azedarach. However, studies on the isolated compounds, toxicity and administration forms to animals are also needed to validate low-cost alternative herbal remedies for use to control gastrointestinal nematodes by family farmers. (C) 2011 Elsevier B.V. All rights reserved.

In vitro and in vivo evaluation of the activity of pineapple (Ananas comosus) on Haemonchus contortus in Santa Inês sheep

The development of resistance to anthelmintics has prompted research into alternative methods of controlling intestinal nematodes in ruminants. This study aimed to assess the activity of Ananas comosus on Haemonchus contortus in Santa Inês sheep. The aqueous extract of pineapple skin (AEPS), bromelain from pineapple stems (B4882) and residue from pineapple processing was evaluated in in vitro and in vivo tests. The enzymatic activity of substances was analyzed by the azocasein method. The egg hatch test (EHT) and larval development test (LDT) were performed using the Embrapa2010 isolate of H. contortus. In the in vivo test, 36 sheep artificially infected with H. contortus were divided into six groups: G1: 2g/kg BW of the aqueous extract administered for three days; G2: 2g/kg BW of the industrial pineapple residue for 60 days; G3: 180mg/animal of bromelain in a single dose; G4: negative control I; G5: positive control (levamisole phosphate); and G6: negative control II. The eggs per gram (EPG) in the feces were counted till 28 days after treatment. LC50 and LC90 were obtained by the probit procedure, while the in vivo test results were analyzed by GLM. The aqueous extract in the in vitro and in vivo test, the bromelain and industrial residue presented 0.102, 0.157, 1.864 and 0.048 enzyme units/mL, respectively. In the egg hatch test, the LC50 and LC90 were respectively 31 and 81mg/mL for the aqueous extract and 0.50 and 2mg/mL for bromelain. In the larval development test, the LC50 and LC90 were respectively 1.7 and 7.3mg/mL for the aqueous extract and 0.019 and 0.086mg/mL for bromelain. In the in vivo test, the general efficacies of the treatments in relation to the negative control were 22.6%, 42.2%, 3.65% and 89% for the aqueous extract, industrial pineapple residue, bromelain and positive control respectively. The transformed EPG values were 3.19±0.59, 3.32±0.25, 2.85±0.66, 3.44±0.50, 2.28±0.93 and 2.75±0.94 for the aqueous extract, industrial residue, bromelain, negative control I, positive control and negative control II respectively. The results for all the treated groups differed significantly (p<0.05) from the positive control, and although the residue presented efficacy of 42.2%, there was no statistical difference (p>0.05) in relation to the negative control. Therefore, both the aqueous extract and bromelain were effective in vitro, but showed reduced anthelmintic efficacy in vivo. For the pineapple residue, the 42.2% in vivo efficacy in reducing the EPG and the possibility of reducing environmental contamination through reuse of industrial residue indicate it can also be useful for control of this parasite. © 2013 Elsevier B.V.

Eficácia de extratovegetais em nematódeos parasitas: avaliação invitro em Haemonchus contortud e avaliação in vitro em Strongyloides venezuelensis

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação da atividade carrapaticida e anti-helmíntica do abacaxi (Ananas comosus L.) em ruminantes

Pós-graduação em Medicina Veterinária - FCAV