Search

The development of new insecticides for vector control that are toxicologically safe and eco-friendly (such as those obtained from industrial by-products) is an important public health concern. Previous research has shown that the obtained tCNSL (technical cashew nutshell liquid) + NatCNSLS (sodium tCNSL sulfonate mixture) emulsion displayed both surfactant properties and larvicidal activity (LC50-24 h 110.6 mg/L). Thus, the emulsion is considered a promising alternative product for the control of Aedes aegypti. The goal of this study was an ecotoxicological evaluation of the tCNSL + NatCNSLS mixture emulsion and its components. In addition, we compared the toxicity of the tCNSL + NatCNSLS mixture emulsion with toxicity data from larvicide currently recommended by the World Health Organization (WHO). Ecotoxicological tests were performed to assess acute toxicity, phytotoxicity, cytotoxicity, genotoxicity, and mutagenicity using Daphnia similis, Pseudokirchneriella subcapitata, Oreochromis niloticus, Allium cepa, and Salmonella enterica serovar Typhimurium. Regarding acute toxicity, D. similis was the most sensitive test organism for the three evaluated products, followed by P. subcapitata and O. niloticus. The highest acute toxicity product was tCNSL. The tCNSL + NatCNSLS mixture emulsion did not show cytotoxic, genotoxic, or mutagenic effects, and showed low acute toxicity to D. similis. In addition, the tCNSL + NatCNSLS mixture emulsion presented a lower or similar toxicological classification to the larvicides recommended by the WHO. Therefore, ecotoxicological tests suggest that the tCNSL + NatCNSLS mixture emulsion can be considered a larvicide environmentally safe way to control Ae. aegypti.

The use of non-plant and plant-derived anesthetics in aquaculture activities is a frequent and necessary practice to maintain fish welfare. Currently anesthetics authorized for use in aquaculture activities are limited, and the use of unauthorized products is common. However, to obtain authorization for use in aquaculture and ensure their safety, anesthetics should be evaluated for their genotoxic potential. Our objective was to evaluate the genotoxicity of three not approved anesthetics commonly used in aquaculture using Astyanax lacustris and Oreochromis niloticus. Both fish species were exposed to six treatments: two with commercial anesthetics (benzocaine and eugenol), one with Lippia alba essential oil (EO), and three controls - negative (without treatment), vehicle (ethanol PA), and positive (cyclophosphamide). Fishes were exposed to all treatments in a water bath for 10 min and were transferred to individual aquariums without anesthetics or controls. Venipuncture of the caudal vein was performed 72 h after the exposure to the anesthetics. Nuclear abnormalities and the micronucleus were analyzed in blood smears, and DNA damage was assessed using comet assay. No genotoxicity effects were verified for fishes exposed to L. alba EO. Eugenol presented genotoxicity to both species. The comet assay showed increased DNA damage in both species induced by benzocaine and eugenol. Thus, L. alba EO was proven to be the safest anesthetic resulting in no genotoxicity and, therefore, may be an interesting alternative to commercial anesthetics used in aquaculture. However, a complete toxicological evaluation is necessary to ensure the safety of its use as an anesthetic.