Análise Fitoquímica, Potencial Anti-Helmíntico e Ensaio Toxicológico em Artemia Salina de Plantas Presentes no Ecótono Amazônia e Cerrado: Leucaena leucocephala, Parkia platycephala e Senna alata.

Abstract

The diseases caused by gastrointestinal parasites are responsible for great economic losses in small ruminants breeding. The control of helminths is accomplished primarily by synthetic anthelmintic medicines. However, these drugs have been administered indiscriminately, promoting the selection of resistant strains of worms. On the other hand, herbal medicines have been proposed as an alternative way for treatment of small ruminants infected by these parasites. However, little is known about of both toxic and therapeutic potentials of plants that could control these helmiths in small ruminants. Therefore, additional studies are required to verify the possible effects of these plants. In this context, the aim of this study was to evaluate the phytochemical profile of the leaves of Leucaena leucochephala and Parkia platychephala, and leaves and flowers of Senna alata, as well as verify toxicity in Artemia salina and their nematicides effects. The plant material was dried, concentrated and homogenized in a rotoevaporator at 45°C to obtain the crude extract (CE). After this procedure, this material was subjected to solvent partitioning polarity and was obtained hexanic, acetatic, butanolic and aqueous fractions. These fractions were used for phytochemical analysis and CLs50 determination through toxicity testing in vitro. Crude extracts were used to evaluate their ovicidal and larvicidal properties. In the hatching inhibition test, the egg suspension was distributed in microtubes with CE diluted in a solution containing 3% Tween 80 at concentrations of 0.05 , 0.1, 0.5, 1.0 and 1, 5 mg/ml, in triplicate. After administration of the extract, the plates were incubated at 26 ± 1 ° C during 48 hours and thereafter read. To assess their larvicida action, CEs were diluted in a Tween 80 in 1% solution and tested on larvae at concentrations of 1.0, 2.5, 5.0 and 7.5 mg/ ml, in triplicate. Readings of the samples were taken every 24 hours for 4 consecutive days, starting from D0. The analysis of the leaves of L. leucocephala revealed the presence of phenols, condensed tannins, flavonoids and saponins. The tests of the sheets P. platycephala hydrolysates revealed the presence of tannins and saponins. Phytochemical tests on the leaves of S. alata were positive for phenols, auronas chalcones, flavones, flavonols, xanthones, and saponins. Moreover, the flowers were positive for phenuronas, chalcones, flavones, flavonols, xanthones and flavononois. The extracts that showed the most toxic effects on A. saline were the leaves of L. leucocephala and S. alata, while extracts from leaves of P. platycephala and flowers of S. alata showed low toxicity. The mortality rate can be due to the activity of the secondary metabolites identified in phytochemical tests. Extracts from the leaves of L. leucocephala, P. platycephala, and leaves and flowers of S. alata promoted significant effect on inhibition of egg development in vitro. The study also showed that the leaves of P. platycephala and S. alata have anthelmintic action on infective larvae Trichostrongylidae.