Evaluation of the antimicrobial activity of silver nanoparticles biosynthesized from the aqueous extract of Schinus terebinthifolius Raddi leaves

Silver nanoparticles (AgNPs) synthesized from green synthesis using medicinal plants are presented as an option for the development of new antimicrobial agents. In this context, this study aims to evaluate the antimicrobial activity of silver nanoparticles synthesized from the aqueous extract of Schinus terebinthifolius Raddi leaves, popularly known as aroeira. A 2(3) factorial design was used to assess the statistical significance of the studied factors, and Box-Behnken design was used to define the optimal conditions for the green synthesis of AgNPs. The studied factors were significant for the synthesis of nanoparticles, and the optimal conditions were pH 9.5, reaction time of 180 min, and 10 g of S. terebinthifolius Raddi leaves. The samples were characterized using UV-Vis spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and dynamic light scattering. Antimicrobial activity was evaluated using the broth microdilution method and through the minimum microbicidal concentration. AgNPs showed greater antimicrobial efficacy compared to the extract, both for bacteria and fungi: bacteriostatic activity against all tested bacteria and bactericidal against Pseudomonas aeruginosa, besides fungistatic action against Candida albicans and Candida glabrata. Finally, the aqueous extract of aroeira leaves was effective in the synthesis of AgNPs, with greater antimicrobial potential than the extract.

Automated summary

This study evaluated the antimicrobial activity of silver nanoparticles synthesized from the aqueous extract of Schinus terebinthifolius Raddi leaves. The results showed that the silver nanoparticles had greater antimicrobial efficacy compared to the extract, inhibiting the growth of both bacteria and fungi.