Aproveitamento de resíduos do peixe Hoplias malabaribus como fonte de proteases ativas contra o nematóide Haemonchus contortus

Abstract

Goats and sheep farming is an important economic activity in Brazil, but gastrointestinal nematode infection became a problem in these small ruminants. The control of these parasites is done with anthelmintic substances commercially available, however, the indiscriminate use of these substances has helped the development of resistant strains, and also impact negatively the environment, being urgent the research of new alternatives for the nematode control. Natural products are being considered very promising for this purpose.The fish industry subproduct is an important biomolecules source, such as proteases with potential use in biotechnological processes. For that matter, the scope of this work was to evaluate the protease anthelmintic effect semi-purified of Hoplias malabaricus viscera over Haemonchus contortus. The fishes were obtained in Viana city, in the Baixada Maranhense. They were measured, heightened and had their pyloric caecum removed. The caecum was homogenized with Tris-HCl solution 0,01M, pH 8,0. The resultant material from this process was centrifuged and the supernatant obtained was named Crude Extract (EB). The EB was submitted to a fractioning through precipitation with ammonium sulfate with saturation intervals of 0-30, 30-60 and 60-90%. Biochemical tests were made for the proteic content determination and proteolytic activity of EB and fractions. The fraction with the highest proteolytic activity (PF) was characterized according to temperature and pH. The anthelmintic essay was done through the inhibition hatchability test of H. contortus eggs. BE, F030, F3060 and F6090 showed 72.8, 5.9, 27.4 and 25.6 milligrams of total proteins, respectively. The proteolytic activity was 1095.8, 662.9,1769.2 and 949.6 UAP/mgP for the BE, F030, F3060 and F6090, respectively. The 30-60% fraction was named enriched fraction with protease (PF). The PF showed the inhibition efficiency of the hatchability of H. contortus eggs with IC 50 of 14.6 μg/mL. The proteases of the pyloric caecum of Hoplias malabaricus fish showed high anthelmintic activity over H. contortus nematode, being a potential molecule for the development of a nematicide