Nanoemulsion from essential oil of Pterodon emarginatus (Fabaceae) shows in vitro efficacy against monogeneans of Colossoma macropomum (Pisces: Serrasalmidae)

Abstract

Outbreaks of diseases pose a major threat to sustainable aquaculture development worldwide. Application of herbal products to combat parasitic diseases provides an alternative approach for sustainable aquaculture. This study investigated the in vitro antiparasitic effects of an oil-in-water nanoemulsion prepared using the essential oil from Pterodon emarginatus, against monogeneans infesting Colossoma macropomum. Gill arches from C. macropomum (47.6 ± 14.5 g and 13.5 ± 1.4 cm) that were naturally parasitized by Anacanthorus spathulatus, Notozothecium janauachensis and Mymarothecium boegeri were immersed in different dispersions of the P. emarginatus nanoemulsions (0, 50, 100, 200, 400 and 600 mg/L). The major compounds presented in the essential oil of P. emarginatus were β-elemene, β-caryophyllene and α-humulene. Characterization of these nanoemulsions showed that they have a small mean droplet size and low polydispersity index, which is concordant with stable systems. In this in vitro trial, the P. emarginatus nanoemulsion concentrations of 100, 200, 400 and 600 mg/L presented 100% helminthic efficacy against monogeneans of the gills of C. macropomum. The highest two concentrations used (400 and 600 mg/L) were seen to immobilize the parasites after only 15 min. Therefore, it would be worthwhile testing these concentrations in therapeutic baths against monogeneans of C. macropomum.

Effects of a nanoemulsion with Copaifera officinalis oleoresin against monogenean parasites of Colossoma macropomum: A Neotropical Serrasalmidae

“…As the main products used for treatment and control of these parasites are chemotherapeutic substances that are highly toxic to fish (Boijink et al., ; Soares et al., ), there is a need for less toxic and novel bioactive compounds (Hashimoto et al., ; Soares et al., ; Zhang et al., ). Phytotherapy is an alternative treatment that has shown promising antiparasitic effects against monogeneans of fish (Costa et al., ; Hashimoto et al., ; Soares et al., ; Zhang et al., ), as well as the use of nanoemulsions containing essential oils (Valentim et al., ).…”

“…Similarly, 100 mg/L of C. duckei oleoresin had 100% efficacy against Anacanthorus penilabiatus and Mymarothecium viatorum of Piaractus mesopotamicus (Costa et al., ). After monogeneans on the gills of C. macropomum has been exposed to nanoemulsion of Pterodon emarginatus essential oil at 400 e 600 mg/L for 15 min, the anthelmintic activity rate reached 100% (Valentim et al., ). Monogeneans of C. macropomum exposed to Lippia alba essential oil at 1,280 and 2,560 mg/L for 20 min also had anthelmintic activity rate reached 100% (Soares et al., ).…”

“…Nanoemulsion prepared from C. officinalis oleoresin had efficacy against monogeneans of C. macropomum , as well as nanoemulsion from Pt. emarginatus essential oil (Valentim et al., ). Thus, these nanoemulsions have potential for use in baths of C. macropomum for treatment of monogenean infections.…”

“…Moreover, nanosize potentially increases the bioactivity of the compounds used (Irache et al., ), such that this is very promising for effective treatment, even at lower concentrations than usual for antiparasitic products. For these reasons, nanoemulsions have been tested as an alternative to increase the stability, efficacy and solubility of essential oils (Valentim et al., ). This nanotechnology technique may be very promising in treatment of parasitic infections for C. macropomum (Soares et al., ; Valentim et al., ), for example, in the use of Copaifera officinalis oleoresin.…”

“…For these reasons, nanoemulsions have been tested as an alternative to increase the stability, efficacy and solubility of essential oils (Valentim et al., ). This nanotechnology technique may be very promising in treatment of parasitic infections for C. macropomum (Soares et al., ; Valentim et al., ), for example, in the use of Copaifera officinalis oleoresin.…”