Larvicidal Activity of <i>Chisocheton erythrocarpus</i> Nano-emulsion Formulation against <i>Aedes aegypti</i>

This study aims to improve the larvicidal activity of crude Chisocheton erythrocarpus extract (CCEE) against Aedes aegypti larvae via nano-emulsion formulation method. The fruits of C. erythrocarpus possesses limonoids with good larvicidal activity against Aedes mosquitoes. Using ternary phase diagrams, four selected formulations were prepared using non-ionic surfactants, methylester and water. The optimized nano-emulsion (S5) was discovered to possess submicron particle size (36.32 nm), low polydispersity index (0.348) and higher zeta potential value (-18.2 mV). After 48-hours, the CCEE and S5 demonstrated respective LC₅₀ values of 139.44 ppm and 75.83 ppm against Ae. aegypti larvae. Higher larvicidal activity of S5 signified improved cuticular penetration of the active ingredient. Moreover, morphological deformities of treated larvae indicated possible interference with the larvae's breathing mechanism, contributing to their death. Thus, the nano-emulsion formulation of C. erythrocarpus extract has the potential to be used as a vector control agent to prevent the spread of dengue infections.