Investigation of the biological activity and toxicity of bioactive silver nanoparticles synthesized via Vitex agnus-castus seed extract on honey bees.

In this study, silver nanoparticles (AgNPs) coated with bioactive molecules were synthesized via Vitex agnus-castus L. (VAC) seed extract (VAC/AgNPs). The synthesized VAC/AgNPs were characterized by surface plasmon resonance (SPR) ultraviolet-visible region spectroscopy (UV-Vis). The hydrodynamic size and surface charge analysis of the particles were measured with a Zeta sizer. The results of UV-Vis and Zeta analysis revealed that AgNPs were synthesized, the size distribution was nanoscale, and the solution was stable. The effects of the synthesized VAC/AgNPs and aqueous extract of VAC seeds on honeybees were investigated by means of lifespan test and histopathological analysis. It was determined that both VAC seed extract and VAC/AgNPs were non-toxic to honeybees at certain doses, positively affected their life span and contributed to their longevity in the life span test. Furthermore, no adverse effects were detected in terms of intestinal health in histopathological examinations. Therefore, VAC/AgNPs are considered to be a promising bioactive agent for honeybees.