Anthelmintic Efficacy of Palmarosa Oil and Curcuma Oil against the Fish Ectoparasite (monogenean).

Monogeneans are a serious threat to the development of aquaculture due to the severe economic losses they cause. The prevention and treatment of this disease are increasingly difficult because of the environmental and health concerns caused by the use of chemical anthelmintics and the emergence of drug resistance. It is thus necessary to search for effective alternatives for the treatment of monogenean infections. In the current study, anthelmintic efficacy of 16 selected essential oils (EOs) was investigated using the goldfish ()- model. The screening experiment indicated that palmarosa oil and curcuma oil had satisfactory anthelmintic activity against with EC values of 10 and 12 mg/L after 24-h exposure, respectively. The in vivo and in vitro assays indicated anthelmintic efficacy of palmarosa oil against was in a time and dose-dependent manner. Interestingly, curcuma oil showed an anesthetic effect on , and its anthelmintic activity was dose-dependent rather than time-dependent in the concentration range tested in this study. Additionally, the 24-h LC (50% lethal concentration) against goldfish of these two EOs was 8.19-fold and 5.54-fold higher than their corresponding EC (50% effective concentration) against , respectively. Moreover, exposure to these two EOs at 100% effective concentration against had no serious physiological and histopathological influence on goldfish. These results demonstrated a high safety for goldfish of these two EOs. Overall, palmarosa oil and curcuma oil could be potential candidates for the treatment of infections in aquaculture.