Nanosuspensão de quercetina: obtenção, caracterização e avaliação da atividade larvicida frente a Aedes Aegypti (Linnaeus 1792) (Diptera : Culicidade)

Abstract

Introduction: Viral diseases transmitted by vectors such as Aedes aegypti (Diptera Culicidae), constitute an important public health problem in Brazil. The use of synthetic chemical insecticides in vector control demonstrates environmental toxicity and causes resistance to mosquitoes. It is observed the need to develop insecticides of natural origin in order to avoid the use of these substances and reduce environmental toxicity. Quercetin is flavonol widely found in foods and has many biological activities. Its actions against certain pests, can be considered an alternative for the control of A. aegypti. However, its low aqueous solubility makes it difficult to produce a water-dispersible product, where the larvae of the mosquito develop. Objective: This work aim to produce quercetin nanosuspension (NS-QUE) and evaluateits the toxicity in A. aegypti larvae compared to its bulk form (QUE). Thus it also evaluate its environmental impact on algae of the species Chlorella vulgaris. Methodology: NS-QUE was prepared by solvent displacement method followed by evaporation. The physico-chemical characteristics were monitored for 30 days. The efficacy of NS-QUE and bulk QUE was performed against A. aegypti larvae for 240 h with concentrations of 100 ppm, 175 ppm, 250 ppm, 375 ppm and 500 ppm and the larval morphology was performed by scanning electron microscopy. Results: NS-QUE were successfully obtained by a low energy method cost technique. NS-QUE and bulk QUE demonstrated toxic effect against the larvae, especially the nanosuspensions. A superior larvicidal activity of NS-QUE was observed when compared to its bulk form, especially in high concentrations. No environmental toxicity was observed for concentrations tested with NS-QUE. Conclusion: These data may contribute to the future use of NS-QUE as a promising candidate for the control of vectors such as A. aegypti, since they present a selective toxic activity in the larvae