Capim-annoni-2 (Eragrostis plana Nees) sob uma nova perspectiva: análise do perfil fitoquímico e efeito entomotóxico sobre Nauphoeta cinerea (Olivier)

Abstract

In the current scenario of systemic contamination of ecosystems, by inappropriate use of pesticides, especially insecticides, the synthesis of bioinsumers is a profitable and sustainable alternative. The grassy Eragrostis plana is an obstacle to Brazilian agricultural activity, since it was accidentally inserted in the country in the 50's. Although its allelopathic potential is well reported in the literature, there are few studies about its phytochemical composition. In this work we propose a new view about this species, where we associate the phytochemical profile with the biological effects in biochemical, behavioral and electrophysiological tests of Nauphoeta cinerea administered with hydroalcoholic extract of E. plana (EHEP in portuguese). The results demonstrated that the presence of phenolic compounds, flavonoids and tannins in E. plana is time dependent. We observed increased self-cleaning activity (grooming) of the legs when the animals were treated with EHEP. Quercetin, one of the major compounds observed in the phytochemical profile of E. plana, has been shown to modulate the grooming activity of legs and antennae, demonstrating that the compound acts in the pathways responsible for this behavior. Locomotion was also significantly altered by EHEP, increasing the distance traveled by the animals and decreasing the time of stopping and the number of episodes of immobility. In addition, we observed inhibition of acetylcholinesterase enzyme activity (AChE) and decreased muscle contractile response in EHEP treatments. Therefore, this work demonstrates the biotechnological potential of capim-annoni-2, which demonstrates modulating the main signaling pathways of invertebrates, suggesting a probable action as a bioinsecticide.