Efeito da suplementação com pó da casca de acácia (Acacia mangium WilldMimosaceae) sobre a resposta imunológica e infecções por Haemonchus contortus e trichostrongylus colubriformis em caprinos

Abstract

The development of goat breeding is largely impaired by losses due to gastrointestinal nematodes infection and the main control method, the use of synthetic anthelmintics face problems due to the growing selection of resistant populations of nematodes, making it imperative to search for new methods of control. The secondary metabolites present in several plants with bioactive properties represent a promising alternative for the control of worms parasites of small ruminants and may act directly or indirectly on the parasites. The aim of this study was to assess whether food supplementation with the powdered bark of Acacia mangium, a plant rich in condensed tannin (TC), would stimulate a pattern of immune response in goats, and consequently affect the experimental infection with Haemonchus contortus and Trichostrongylus colubriformis. This experiment was carried out with 18 goats, initially free of helminth infection, that were distributed in three groups: I - control (n = 6), II - Acacia (n = 6) and III - Acacia + PEG (n = 6). The animals in groups II and III received together with the concentrated (88% corn meal and 12% soybean meal) supplementation with bark of A. mangium (CT 100mg / kg BW), and the group III also received additional treatment of A. mangium with 10 g of polyethylene glycol. Fifteen days after the begin the administration of the plant, all animals were infected orally with a pool of 12,000 L3 larvae of H. contortus and T. colubriformis. After 35 days of infection the animals were euthanized and parasite burden of abomasum and thin intestine was determined. Blood samples and feces were collected for determination of immunological parasitological and parameters throughout the experiment. Our results showed that supplementation with A. mangium promoted changes in the immune profile of goats, inducing the increase of the number of circulating CD4 + T lymphocytes producing IL-4 and CD8 + T producing IL-4 and IFN-. Moreover, the supplementation with A. mangium demonstrated to be also effective for reducing the burden of parasitic adult worms of T. colubriformis despite it not prevented the establishment of infection and H. contortus and T. colubriformis. These results suggest that A. mangium may present bioactive property that induce an immune response associated with the control of helminth infections.