Avaliação da atividade larvicida do extrato hidroetanólico de acmella oleracea (L.) R. K. Jansen sobre Aedes aegypti e Culex quinquefasciatus (díptera : culicidae)

Abstract

Introduction: Currently, the search for innovative and renewable substituents, mainly derived from plants, that present significant biological activities, are gaining more space in the scientific community, as these are obtained from renewable and environmentally profitable sources. The species Acmella oleracea popularly known as jambu, is a species rich in isobutylamides, where the main molecule of this species is the alkaloid N-isobutylamide. Objectives: The objective of this work was to evaluate larvicidal activity of the crude hydroethanolic extract of the leaves of Acmella oleracea against larvae of Aedes aegypti and Culex quinquefasciatus. Methodology: The extract was prepared using 70% alcohol, this was rotoevaporated and lyophilized. This was then dissolved in dimethylsulfoxide (DMSO) in different concentrations, (2.5, 5, 7.5, 10 and 15 ppm) for Ae. aegypti, (5, 10, 20, 30 and 40 ppm) to Cx. quinquefasciatus. The test was performed in quintupleta using Becker of 100 mL with 10 larvae in each. For the test, distilled water and DMSO (1%) were used as controls. The mortality rate was determined after 24 hours, where larvae that did not respond to stimulation were considered dead. Results and discussion: In the bioassay the mortality in 24 hours for Ae. aegypti at 15 ppm was 58% and at 2.5 ppm it was 18%, with the LC50 values 11.41ppm and LC90 being 23.23 ppm. The larvicidal action for Cx. Quinquefasciatus showed 54% mortality at 40 ppm and 13% at 5 ppm, showing values of LC50 32.40 ppm and LC90 68.24 ppm. In this way, the extract showed high mortality, even in low concentrations, and this may be associated with the presence of the alkylamide spilanthol, which was identified by gas chromatography and mass spectroscopy. Conclusions: In this way this study contributes with information about material of vegetal origin that can be used in the integrative practices in the control of vectors of diseases