Monoterpene-rich biocidal activity of nanoliposomes containing Trachyspermum ammi (L) Sprague essential oils against larvae of Anopheles stephensi Liston, the main malaria mosquito vector

Aim and Background: Controlling mosquito vectors in immature stages using larvicides is a practical strategy to stave off mosquito-borne diseases such as malaria. Developing nanoliposomes containing essential oil (EO) is a promising approach for efficacy and stability improvements of EOs-derived larvicides. The main aim of this investigation was to assess the efficacy of nanoliposome (NL) containing Trachyspermum ammi (L) EO (TAEO) as a new potential formulation to control larval Anopheles stephensi Liston (Diptera, Culicidae) mosquitoes. Methods: The chemical constituents of TAEO were investigated; encapsulation of TAEO into nanoliposomes took place. Nanoliposomes containing TAEO (TAEO-NL) with a particle size of 54.6 ± 5 nm and narrow particle size distribution (Span 1) were prepared using the ethanol injection method. Besides, the successful loading of TAEO was confirmed using Attenuated Total Reflection-Fourier Transform Infra-Red (ATR-FTIR) spectroscopy analysis. Results and discussion: The TAEO had 13 constituents about 95% of which involved monoterpenes. The dominant component (48.22%) was thymol. A significant difference was observed in the efficacy of TAEO-NL and TAEO with lethal concentration 50% (LC50) values of 14.09 and 59.47 μg/mL, respectively (P 0.05) against larval An. stephensi, a major malaria vector in the adult stage. Conclusion: This nano-formulation could be suggested as a stable green product against insects to combat transmission of deadly infectious diseases with possible field applicability scope.