Efeito da ação antiparasitária de extratos de acículas de Pinus sp. sobre o modelo de Artemia fransciscana

Abstract

Over the years, aquaculture has shown increasing development in terms of production. In intensive farming systems, parasitic diseases can represent a major problem in fish farms, causing significant economic losses. Alternatives to control parasites with chemoterapeutical are ineffective and present a great risk of environmental damage. For these reasons, more and more, natural treatment alternatives using plant extracts have been sought. The treatment with aqueous extract of needles of Pinus sp. is popularly used among some fish farmers and the resin showed effective results in vitro treatment. The objective of this work was to evaluate the best methods to obtain the Pinus extract and to test the toxicity against the experimental model of Artemia fransciscana. Two types of solvent (ethanol and water) were tested for the extraction of dry and green needles, being characterized as to the concentration of total phenolic compounds, flavonoids and antioxidant activity (DPPH and FRAP). The second stage of the project was to determine the lethal concentration (LC50 - 24 hours) of Pinus extracts against Artemia franciscana. The extracts of green needles showed the highest concentration of all parameters analyzed, and the best solvent observed was ethanol. The results of the toxicological test were promising, obtaining LC-50 values of 3.27 ppm for the aqueous extract of green needles, 2.89 ppm for the ethanolic extract of green needles and 2.12 ppm for the ethanolic extract of dry needles. In the aqueous extract of dried needles, it was not possible to determine the value of LC-50, since 50% mortality was not reached in any of the concentrations tested. It is concluded that the aqueous and ethanolic extracts of green needles and the ethanolic extract of dry needles have a toxic effect on brine shrimp. Therefore, they can be a promising resource for the control of parasites in fish farms and a possible natural alternative against lernea and other ectoparasites.