Dados do Trabalho

Título

Larvicidal and anti-acetylcholinesterase activities of fractions obtained from Amazonian plant against Aedes aegypti larvae (Linnaeus, 1762) (Culicidae)

Introdução

Dengue, Zika and Chikungunya are arboviruses transmitted by Aedes aegypti (Culicidae) to more than 100 countries due to their significant ability to adapt to human and environmental conditions. In addition, the resistance that this mosquito presents to commercial insecticides makes it difficult to control the vector, as well as arboviruses. On the other hand, A. aegypti control strategies focus on Amazonian plants of the genus Piper (Piperaceae) with insecticidal activities, such as Piper purusanum C.DC, whose essential oil rich in β-caryophyllene, α-humulene and germacrene D showed activity against Aedes and Anopheles larvae. On the other hand, the larvicidal activities of non-volatile products obtained from this species are not yet fully known.

Objetivo(s)

Thus, the aim of the study was to investigate the activity and mechanism of larvicidal action of fractions obtained from P. purusanum against A. aegypti.

Material e Métodos

The species P. purusanum was collected in the state of Amazonas, Manaus, Brazil (latitude 2° 46′ 58.2″S, longitude 60° 05′ 2.8″ W). The chloroform (FCEPp) and hexane (FHEPp) fractions were obtained from P. purusanum leaves and evaluated at concentrations from 500 to 31.25 µg/mL against A. aegypti larvae according to the WHO protocol for larvicidal tests. The mechanism of action of the fractions was measured by a chemical reaction using the enzyme acetylcholinesterase (AChE).

Resultados e Conclusão

The data showed that the FCEPp fration (LC50 = 66.88 µg/mL and LC90 = 132.52 µg/mL) was more active against A. aegypti larvae when comparing the FHEPp (LC50 = 129.48 µg/mL and LC90 = 327.39 µg/mL) (p < 0.05). In addition, FCEPp and FHEPp also inhibited the action of AChE (IC50 of 2.28 and 2.07 µg/mL), indicating a mechanism of neurotoxic action against A. aegypti larvae. These results encourage the performance of chromatographic studies to identify the chemical constituents in the fractions responsible for the larvicidal and neurotoxic activity.

Palavras-chave

Amazon, Piper, Aedes, arboviruses.