Plant Extract Based on Deep Eutectic Solvent-Mediated Biosynthesis of Silver Nanoparticles: Cytotoxicity and Antibacterial Effects

Abstract

Deep eutectic solvent DES-based grape pomace extracts (GPE) were used to synthesize silver nanoparticles (AgNPs) for the first time. This paper presents a synthesis of AgNPs by a novel method with GPE obtained by an eco-friendly “green” solvent, namely, betaine-lactic acid and proline-lactic acid DESs. Compared with the water-based GPE, the DES-based grape pomace extracts contain lower reducing powers but additionally act as capping agent, which is the more important property for the creation of necessary particle nanosize and dispersion with colloidal stability. DESs were synthesized using a heating method, and Fourier transform infrared spectroscopy (FTIR) was carried out to confirm the formation of the DES. The phytochemical profile of GPE exhibits a high amount of hydroxycinnamic acids (23%), followed by anthocyanins (19%). The silver nanoparticles with a round shape were noticed on the scanning electron microscopy micrographs with the particle size in the range of 10–20 nm. The disc diffusion technique (DDT) showed that the AgNPs exhibited significant antibacterial activity against Gram-negative bacteria Escherichia coli (E. coli) UKM В-906 and Gram-positivespore-formingBacillus subtilis (B. subtilis) UCМ В-506T. Mitotic index (MI) and chromosomal aberrations (CAs) were assessed by A. cepa assay. The synthesized silver nanoparticles do not induce cytogenotoxic and genotoxic changes in Allium cepa L. with nanoparticles at concentrations up to 10%.