Folhas de Annona crassiflora Mart. (Annonaceae) no controle de Haemonchus contortus

Abstract

The production of ruminants is important for the economy of different agricultural regions. However, one of the great obstacles for the creation is the gastrointestinal helmintoses, that cause great losses in the productivity. Resistance to conventional anthelminthic makes it difficult to control these nematodes mainly in small ruminants. In this way, the search for new forms of control is fundamental and phytotherapy has been highlighted as an alternative. The ethnopharmacological literature has registered medicinal and anthelminthic properties in plants of the genus Annona. Annona crassiflora, known as Panã, is a species present in the Cerrado and important for the production of tasty fruits. In this research, the objectives were to evaluate the phytochemical composition of the leaves of this plant and its in vitro and in vitro effects for the control of the nematode Haemonchus contortus in sheep. High performance liquid chromatographychromatograms of the aqueous extract (AE), ethanolic extract (EE) and ethyl acetate (AE) extract of A. crassiflora indicated the presence of flavonoids. The tannin contents for AE, EE and AE were 6.93; 12.05 and 0.64%, respectively. In the hatchability inhibition test, ethanolic extract was the most effective, with CL90 of only 8.96 mg / mL. However, after the removal of the tannins, the aqueous extract was the most effective, presenting LC90 of 4.27 mg / mL. When evaluating inhibition of larval development, EA presented CL90 69.14 mg / g coproculture. In the in vivo tests, dry leaves of A. crassiflora were given at 2.75g (ms) / kg for three days, however no efficacy was found in fecal egg reduction per gram of feces and changes in weight gain and physiological parameters,comparing with the group of untreated lambs. In this study, high efficacy was observed for inhibition of hatchability and larval development of H. contortus and after the removal of tannins, the extracts were more efficient. Future studies should evaluate the administration of the plant or its extracts in longer periods or higher doses and in formulations protected of the ruminal action to promote better reduction of eggs per gram of feces in animals with haemonchosis.