311 Two pools of recycling synaptic vesicles in motor nerve terminals of Drosophila larvae

Abstract

To assess the larvicidal activity of titanium dioxide nanoparticles (TiO2NPS) synthesized from the root aqueous extract of Morinda citrifolia (M. citrifolia) against the larvae of Anopheles stephensi (An. stephensi), Aedes aegypti (Ae. aegypti) and Culex quinquefasciatus (Cx. quinquefasciatus).The M. citrifolia broth solution was prepared by taking 8 g of the powdered root of M. citrifolia in 250 mL Erlenmeyer flask along with 100 mL of distilled water and boiled for 5 min. About 20 mL of M. citrifolia root extract was added into the 80 mL of an aqueous solution of 5 mmol/L TiO(OH)2 for the reduction under continuous stirring for 4 h at 50 °C. Synthesized TiO2NPS were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, field emission scanning electron microscopy and energy dispersive X-ray spectroscopy. X-ray diffraction confirmed the crystalline nature of the nanoparticles. Toxicity studies were carried out against non-target fish species Poecilia reticulata, the most common organism in the habitats of An. stephensi, Ae. aegypti and Cx. quinquefasciatus.The Fourier transform infrared spectroscopy for TiO2NPS synthesized by M. citrifolia root extract showed band at 3 426 cm−1, 1 637 cm−1 and 714 cm−1. The 3 426 cm−1 showed O-H stretching due to alcoholic group; 1 637 cm−1 showed N-H bend due to alcoholic group. In particular, the 1 637 cm−1 indicated the presence of H bend bond for 1° for proteins. A peak was observed around 714 cm−1 due to Ti-O-O bond. Field emission scanning electron microscopy and transmission electron microscopy showed the spherical nature of the nanoparticles with a size of 20.46–39.20 nm. The biosynthesized TiO2NPS showed maximum activity against the larvae of An. stephensi, Ae. aegypti and Cx. quinquefasciatus when compared to the aqueous extract of M. citrifolia. Toxicity studies revealed no toxicity towards Poecilia reticulata at LC50 and LC90 doses of TiO2NPS.TiO2NPS could be used along with Poecilia reticulata in integrated vector control.