EFICÁCIA DO PRODUTO A BASE DE EPRINOMECTINA 2% CONTRA Haemonchus placei, Cooperia pectinata, Cooperia punctata, Oesophagostomum radiatum E Trichostrongylus axei EM BOVINOS ARTIFICIALMENTE INFECTADOS

Prejuízos causados por helmintoses em bovinos ocorrem por ação direta, pelos danos ao rebanho, e indireta, resultantes do custo financeiro para o controle parasitário. A prática de controle estratégico, com utilização correta de anti-helmínticos e manutenção de cargas parasitárias, podem gerar resultados satisfatórios para um rebanho quanto a aspectos de produtividade. A eprinomectina, , pertence ao grupo das lactonas macrocíclicas e possui ação endectocida. O estudo teve como objetivo avaliar a atividade anti-helmíntica da eprinomectina 2%, pela via injetável subcutânea, empregada na dose de 200mcg/Kg de peso corporal, em bovinos artificialmente infectados por nematódeos gastrintestinais. Doze bovinos mestiços foram infectados artificialmente com uma cultura mista de 150.000 L3 de uma cultura de Haemonchus placei, Cooperia pectinata, Cooperia punctata, Oesophagostomum radiatum e Trichostrongylus axei (CEUA IV/UFRRJ 9867250516). Após 42 dias os animais foram divididos em grupo controle e tratado, randomizados de acordo com as contagens médias de OPGs (ovos por gramas de fezes) realizadas nos dias -7 e -2. No dia 0 os animais tratados. Foram realizadas as contagens de OPGs dos animais nos dias +1, +3, +5, +7 +9, +11 e +13. Os animais foram eutanasiados e necropsiados nos dias +14 e +15. O número médio das contagens de OPGs e o número de helmintos presentes nos bovinos tratados foram estatisticamente menores que nos bovinos do grupo controle (p≤0,05). No grupo tratado foram encontrados por animal uma média de 355 espécimes de C. pectinata, 84,5 de T. axei, 445,67 de H. placei, 818,33 de C. punctata e 29,17 de O. radiatum. Já no grupo tratado a média de parasitos encontrados por animal foi de zero para C. pectinata e T. axei, 3,33, 20 e 1,33 para H. placei, C. punctata e O. radiatum respectivamente. Houve eficácia de 100% para C. pectinata e T. axei, 99,25% para H. placei, 97,56% C. punctata e 95,43% para O. radiatum. Como no presente estudo, testes anti-helmínticos controlados e estudos de redução de OPG realizados em outros países relatam a eficácia da eprinomectina, gerando uma nova perspectiva para o controle de helmintos gastrintestinais de bovinos, com o uso seguro de uma lactona macrociclica em vacas em lactação. Conclui-se que o produto se mostrou efetivo contra as espécies H. placei, C. pectinata e T. axei e efetivo contra C. punctata O. radiatum. em teste controlado.

Anthelmintic Activity of Nauclea diderrichii Leaf Extracts and Fractions Against Adult Haemonchus placei

Background: Nauclea diderrichii is used in West and Central Africa countries for its insecticidal and antiparasitic properties. There is, however, no documentation on its activity against parasitic nematodes.Objectives: This study investigated N. diderrichii leaf extracts and fractions for anthelmintic activity against adult Haemonchus placei, an abomasal parasitic worm that infect cattle.Materials and Method: Pulverized dried leaves of N. diderrichii was defatted using n-hexane, followed by successive extraction using chloroform and acetone. The extracts were evaluated for anthelmintic activity by incubating ten (10) adult H. placei in a range of concentrations (1 ̶ 20 mg/mL) for 3h and then counting the number of confirmed dead worms. The most active extract was subjected to chromatographic fractionation, and the thin layer chromatographic (TLC) profile of the fractions was documented. The dried fractions were then evaluated for anthelmintic activity and anthelmintic data were fitted to a non-linear regression equation (Log [extract or fraction] vs. response; variable slope) to produce best-fit sigmoidal curves and LC50 values computed.Results: Anthelmintic assay shows that acetone extract is worm-active with a best-fit LC50 of 16.24 mg/mL, while the chloroform extract was inactive. Fractionation of the acetone extract yielded three fractions (FA, FB and FC) and TLC profile revealed the various secondary metabolites in the fractions. Of the fractions, only fraction B was active against H. placei with LC50 of 12.24 mg/mL.Conclusion: Acetone extract of N. diderrichii leaf possessed anthelmintic activity against adult H. placei, and could be useful as anthelmintic phytomedicine to deworm cattle. Keywords: Anthelmintic, Haemonchus placei, Nauclea diderrichii, Chromatography

Anthelmintic activity of Ocimum gratissimum and Cymbopogon citratus leaf extracts against Haemonchus placei adult worm

Medicinal plants are promising, as source of alternative solution to the problem of parasitic helminth infections that hamper the sustainable supply of products from farm animals. Ocimum gratissimum and Cymbopogon citratus leaves are commonly used internally to treat worms, relieve abdominal pains and stomach ache. This study, therefore, evaluated their leaf extracts for anthelmintic activity against Haemonchus placei worm from cattle; the most active extract being subjected to phytochemical analysis. The extracts, obtained by maceration using acetone, were evaluated for anthelmintic activity by exposing adult H. placei to a range of concentrations (5-60 mg/mL) for 3 hours and then counting the number of confirmed dead worms. Anthelmintic activity data were fitted to a non-linear regression equation (Log [extract] vs. response; variable slope) to produce best-fit sigmoidal curves from which LC50 values were computed. The best-fit LC50 values, found to be significantly different (alpha < 0.0001), were 17.70 mg/mL and 56.04 mg/mL for C. citratus and O. gratissimum, respectively, suggesting that C. citratus is three times more potent than O. gratissimum. Phytochemical analysis of C. citratus indicated the presence of alkaloids, tannins, steroids, saponins, terpenoids and flavonoids. Cymbopogon citratus could be useful as an anthelmintic phytomedicine against livestock parasitic helminths. Keywords: Anthelmintic; Haemonchus placei; Motility assay; Ocimum gratissimum; Cymbopogon citratus

Caesalpinia coriaria fruits and leaves extracts possess in vitro ovicidal activity against Haemonchus contortus and Haemonchus placei

The ovicidal effect of hydro-alcoholic extracts from mature fruits and dried leaves of the Caesalpinia coriariatree, against Haemonchus contortus and H. placei was evaluated by the egg hatching inhibition test (EHIT). Secondary compounds within the extracts were identified by high performance liquid chromatography. Five extract concentrations were assessed in the inhibition tests (25.0, 12.5, 6.2, 3.1 and 1.5 mg/mL), using distilled water and Thiabendazole (0.5 mg/mL) as negative and positive controls, respectively. The results were analysed under a 2 × 2 × 6 completely randomized factorial design, and mean differences were established by the Tukey’s post hoc test. The 50% (EC50) and 90% (EC90) effective concentrations for each extract were determined using a Probit analysis.A concentration-dependent ovicidal effect of hydro-alcoholic extracts from both leaves and fruits was observed, reaching a 100% efficacy against both nematode species with the 25.0 mg/mL concentration (p < 0.05). The EC50 for the fruit and leaves extracts were established as 1.63 and 3.91 mg/mL, and as 3.98 and 11.68 mg/mL, against H. contortus and H. placei, respectively. The most important secondary compounds identified in extracts were free-condensed tannins, gallic acid and methyl-gallate.In conclusion,hydro-alcoholic extracts from C. coriaria mature fruits and dried leaves inhibit in vitro egg hatching of H. contortus and H. placei.