Plants of the Cerrado naturally selected by grazing sheep may have potential for inhibiting development of Haemonchus contortus larva.

Plant species naturally selected by sheep grazing in the Cerrado region of Brazil were assessed in vitro for activity against Haemonchus contortus. One year of observations showed the plant families in the region exhibiting greatest richness to be Fabaceae, Rubiaceae, Malpighiaceae, Bignoniaceae, Myrtaceae, and Annonaceae. Nine species commonly selected by grazing sheep showed variation in the selectivity index with respect to the dry and rainy seasons. Coproculture was conducted in five replicates of 11 treatments: ivermectin, distilled water, or dehydrated leaves of nine selected plant species administered at 333.3 mg g(-1) fecal culture. The dried powder of Piptadenia viridiflora and Ximenia americana leaves significantly reduced the number of infective larvae compared to the distilled water control. These species showed efficacy of over 85 % despite low concentrations of proanthocyanidin. High-performance liquid chromatography analyses of extracts of these plants showed major peaks of UV spectra characteristic of flavonoids. Those naturally selected plant species with high antihelminthic efficacy show promise for use in diet as an alternative control of H. contortus in sheep.

Anthelminthic efficacy of banana crop residues on gastrointestinal nematodes of sheep: in vitro and in vivo tests.

Resistance to anthelminthics is common due to intensive and incorrect use. In searching for alternatives, extracts of banana plant were evaluated for egg hatching inhibition and fecal egg count reduction of sheep nematodes. Aqueous extracts of the leaf, pseudostem, and heart of the banana plant cv. Prata anã were tested at concentrations of 0.31, 0.62, 1.25, 2.5, 5.0, and 10.0 mg ml(-1) in egg hatching inhibition tests. For in vivo analysis, aqueous extracts were evaluated at dosages calculated according to the 10% lethal dose derived from acute toxicity testing in mice. Efficacy was evaluated at two time periods following oral administration. For the banana extracts at 2.5 mg ml(-1), egg hatching was significantly fewer than the negative control, with an LC(50) and LC(90) of 0.19 and 0.84 mg ml(-1), respectively. In vivo analysis for weeks 1 and 2 following a single treatment with aqueous leaf extract showed 33.1% and 32.5% anthelminthic efficacy, respectively. Further research on higher dosages with more frequent administration is needed to evaluate the potential for utilizing banana plant residues in gastrointestinal nematode control.

Eficácia de resíduos da bananicultura sobre a inibição do desenvolvimento larval em Haemonchus spp. provenientes de ovinos / Efficacy of banana crop residues on the inhibition of larval development in Haemonchus spp. from sheep

Com o presente estudo, foi avaliada a eficácia in vitro de extratos vegetais de resíduos da bananicultura sobre a inibição do desenvolvimento larval de nematódeos gastrintestinais de ovinos. A técnica de coprocultura quantitativa e qualitativa foi empregada para avaliar a eficácia anti-helmíntica dos extratos aquosos de folhas, pseudocaules e corações de bananeiras da cultivar 'Prata Anã', nas concentrações 25, 75 e 150mg mL-1, em um delineamento inteiramente casualizado. Os resultados obtidos demonstraram que os três extratos, em concentrações iguais ou superiores a 75mg mL-1, reduziram significativamente (P<0,05) o desenvolvimento larval dos nematódeos, com eficácia acima de 96,9 por cento. A identificação das larvas desenvolvidas revelou a ocorrência de Haemonchus spp. nas culturas avaliadas, permitindo concluir que as partes testadas da bananeira apresentam propriedades anti-helmínticas sobre o desenvolvimento larval desse importante parasito.

This study evaluated the in vitro efficacy of aqueous extracts from banana crop residues on the inhibition of larval development of sheep gastrointestinal nematodes. The quantitative and qualitative coproculture technique was performed to evaluate the anthelmintic efficacy of the aqueous extract of leafs , pseudostems and hearts from banana plants, cv 'Prata Anã', at 25, 75 and 150mg mL-1 concentrations, in a completely randomized design. The results showed that the three extracts, in concentrations equal to or greater than 75mg mL-1, decreased significantly (P<0.05) the nematodes larval development, with efficacy up 96.9 percent. The identification of the developed larvae revealed occurrence of Haemonchus spp. in the evaluated samples, allowing to conclude that the tested parts of this plant showed anthelmintic properties on the larval development of this important parasite.