Optimization and Characterization of Essential Oil Nanoemulsions Using Ultrasound for New Ecofriendly Insecticides

摘要

This study developed and evaluated the toxicological effects of new stable nanoemulsions (NEs) of peppermint essential oils (EOs) and palmarosa EO + linalyl acetate (LA) using ultrasound cavitation. Moreover, the study analyzed the effect of LA in the stabilization process of palmarosa NEs. Peppermint NEs had sizes of 34 nm and polydispersity index (PDI) values of 0.424, whereas palmarosa NEs showed sizes of 15 nm and a PDI of 0.078. Peppermint NEs were stable for 30 days and palmarosa NEs for 120 days. The insecticidal effect of NEs was also evaluated against Cx p. pipiens and Plodia interpunctella larvae. In Culex pipiens pipiens, the LC50 values were 31.24 ppm for peppermint NEs and 32.30 ppm for palmarosa + LA NEs. In P. interpunctella, the NEs were combined with beta-cypermethrin and the LC50 values were 0.12 mu g larvae(-1) for peppermint NEs and 0.23 pg larvae(-1) palmarosa + LA NEs. In addition, the NEs showed no toxicity effect in nontarget organisms such as Artemia salina and Tenebrio molitor. Finally, viability on mammalian cell culture models was evaluated and it was also observed that NEs did not affect the cell viability after 3 and 7 days of exposure.