Green Nanobioinsecticide of a Brazilian endemic plant for the Aedes aegypti control

The search for sustainable alternatives for larval control of the Aedes aegypti (Diptera: Culicidae) mosquito, the vector that transmits Dengue Fever, is urgently needed in tropical and subtropical regions. This work aims to realize the chemical characterization of the essential oil from Xylopia ochrantha Mart. Leaves, prepare a stable nanoemulsion, and determine its hydrophilic-lipophilic balance (HLB) and larvicidal activity against the 3rd instar larvae of Aedes aegypti. Aerial dried parts of Xylopia ochrantha were collected at Restinga de Jurubatiba National Park (Brazil), and the essential oil was obtained by hydrodistillation using a Clevenger-type apparatus. The chemical characterization was done by gas chromatography, revealing germacrene D (17.8%), bicyclogermacrene (17.4%), and δ-elemene (13.9%) as the major compounds. The nanoemulsion prepared by the low-energy method presented a droplet size of 75.56 nm, a polydispersion index of 0.271, and a relative hydrophilic-lipophilic balance (HLB) value of 14.22. The LC50 was 192.5 μg/mL within 48 h against the 3rd instar Ae. Aegypti larvae. This study concluded that the nanoemulsion obtained from the essential oil of X. ochrantha leaves proved helpful for controlling this vector, which is responsible for causing diseases with a great impact on public health. Moreover, it gives visibility to the restinga, an important ecosystem. It points to the possibility of developing environmentally friendly products to help solve significant public health problems.