Development, larvicide activity, and toxicity in nontarget species of the Croton linearis Jacq essential oil nanoemulsion

• Published in: Environmental science and pollution research international 2020-03, Vol.27 (9), p.9410-9423
• Main Authors: Amado, Jesus Rafael Rodriguez, Prada, Ariadna Lafourcade, Diaz, Jesus Garcia, Souto, Raimundo Nonato Picanço, Arranz, Júlio Cesar Escalona, de Souza, Tatiane Pereira
• Format: Article
• Language: English
• Subjects: Aedes; Animals; Aquatic insects; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Croton; Croton linearis; Cytotoxicity; Design optimization; Earth and Environmental Science; Ecotoxicology; Emulsions; Environment; Environmental Chemistry; Environmental Health; Environmental science; Essential oils; Evaluation; Insect control; Insecticides; Larva; Larvicides; Lipophilic; Mosquito Vectors; Mosquitoes; Nanoemulsions; Oils & fats; Oils, Volatile; Plant Leaves; Research Article; Stirring; Toxicity; Toxicity testing; Volatile compounds; Waste Water Technology; Water Management; Water Pollution Control
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-020-07608-8

In this study, the essential oil (EO) from leaves of Croton linearis Jacq was extracted and characterized by GC/MS. The EO hydrophilic-lipophilic balance required (rHLB) for nanoemulsion (NE) development was determined by the Griffin’ method. For evaluating the larvicidal effect against Aedes aegypti , the preparation process of NE was optimized, using a central composite design. It was also evaluated the possible toxic effect of NE in nontarget species. The leaves of C. linearis contain 1.50% of EO, enclosing 61 volatile compounds, mainly eucalyptol (26.66%). The best surfactant, oil:water ratio (4.5–5.0-91.5; % w:w:w), allows to achieve the optimal NE, using a stirring speed of 800 rpm, the addition rate of 0.5 ml/min, and a stirring time of 30 min. NE (with particle size = 163 nm) showed a larvicide effect (LC 50  = 17.86 μg/mL) more potent than the whole EO (LC 50  = 64.24 μg/mL). NE showed neither hemolytic effect nor cytotoxicity, and it was classified as a nontoxic product, according to the OECD class toxicity test (IC 50  > 2000 mg/kg). This product arises in a new green bio-larvicide that could be used for mosquito control.