Dados do Trabalho

Título

Larvicidal activity of the essential oil and fenchone from Amazonian plant against dengue vectors and low toxicity against Toxorhynchites haemorrhoidalis and Gambusia affinis

Introdução

Malaria and dengue are diseases transmitted by Anopheles and Aedes mosquitoes resistant to commercial insecticides, which are toxic to non-target animals. Another side, alternative eco-friendly control strategies are being focused on the natural products extracted from Amazonian plants.

Objetivo (s)

The aim of the study was to investigate the mechanism and larvicidal activities of essential oil (EO) from Tetradenia riparia (Lamiaceae) and fenchone against malaria and dengue vectors, as also against non-target animals.

Material e Métodos

The EO from T. riparia was extracted by hydrodistillation and characterized by gas chromatography–based approaches, being its toxicity, along with a fenchone, evaluated against An. darlingi, An. albitarsis, An. triannulatus, An. nuneztovari, Ae. aegypti and Ae. albopictus (Culicidae), as well as against Toxorhynchites haemorrhoidalis (Culicidae) and Gambusia affinis (Poeciliidae). In addition, their acetylcholinesterase (AChE) activities were evaluated.

Resultados e Conclusão

The EO of T. riparia yield 1.4 ± 0.17% and presented fenchone (31.62%) as the main constituent. Moreover, the EO showed significant larvicidal activity against Anopheles (LC50 from 30.21 to 35.21 ppm) and Aedes (LC50 from 29.31 to 40.76 ppm). On the other hand, fenchone showed higher larvicidal activity against Anopheles (LC50 from 5.93 to 6.86 ppm) and Aedes (LC50 from 3.65 to 7.00 ppm) than EO. Furthermore, the EO and fenchone presented significant inhibition of AChE (IC50 from 1.93 to 2.65 ppm). Regarding the toxicity, α-cypermethrin (positive control) was extremally toxic against T. haemorrhoidalis and G. affinis (LC50 of 0.22 to 0.29 ppm) (IS/FSP from 1.04 to 2.23) than the EO and fenchone that presented low toxicity (LC50 of 722.38 to 957.17 ppm) (IS/FSP from 2.59 to 12.18). Thus, the present study demonstrated that EO of T. riparia and its main constituent fenchone could be an alternative ecologic to control malaria and dengue vectors.

Palavras-chave

Amazonian, Anopheles, Aedes, Lamiaceae, biological control

Agradecimentos

CNPq, FAPEAM