The mixture of cashew nut shell liquid and castor oil results in an efficient larvicide against Aedes aegypti that does not alter embryo-fetal development, reproductive performance or DNA integrity

Dengue fever, chikungunya fever and Zika virus are epidemics in Brazil that are transmitted by mosquitoes, such as Aedes aegypti or Aedes albopictus . The liquid from shells of cashew nuts is attractive for its important biological and therapeutic activities, which include toxicity to mosquitoes of the genus Aedes . The present study evaluated the effects of a mixture of surfactants from natural cashew nutshell liquid and castor oil (named TaLCC-20) on the mortality of larvae and on the reproductive performance, embryonic and fetal development and genetic stability of Swiss mice. A total of 400 Ae . aegypti larvae (third larval stage) were treated with TaLCC-20 concentrations of 0.05 mg/L, 0.5 mg/L, or 5 mg/L (ppm). Twenty pregnant female mice were also orally administered TaLCC-20 at doses of 5 mg/kg and 50 mg/kg body weight (b.w.), and 10 animals were given only drinking water at 0.1 mL/10 g b.w. (orally). The results of a larvicide test demonstrated that 5 mg/mL TaLCC-20 killed 100% of larvae within three hours, which is comparable to the gold standard indicated by the Ministry of Health. Overall, these results show that TaLCC-20 is an efficient larvicide that does not induce genetic damage. In addition, changes in reproductive performance and embryo-fetal development appear positive, and the formulation is cost effective. Therefore, TaLCC-20 is an important product in the exploration of natural larvicides and can assist in fighting mosquitos as vectors for dengue fever, chikungunya fever and Zika virus, which are emerging/re-emerging and require proper management to ensure minimal harm to the human population. Therefore, TaLCC-20 can be considered a key alternative to commercial products, which are effective yet toxigenic.