Antioxidant, antimicrobial and cytotoxic activities of gold nanoparticles capped with quercetin

Felipe Guzansky Milanezi; Leandra Martins Meireles; Marcella Malavazi de Christo Scherer; Jairo P de Oliveira; André Romero da Silva; Mariceli Lamas de Araujo; Denise Coutinho Endringer; Marcio Fronza; Marco Cesar Cunegundes Guimarães; Rodrigo Scherer

doi:10.1016/j.jsps.2019.07.005

Antioxidant, antimicrobial and cytotoxic activities of gold nanoparticles capped with quercetin

Saudi Pharm J. 2019 Nov;27(7):968-974. doi: 10.1016/j.jsps.2019.07.005. Epub 2019 Jul 11.

Affiliations

¹ Pharmaceutical Sciences Graduate Program, Universidade Vila Velha, 29102-920 Vila Velha, ES, Brazil.
² Department of Morphology, Federal University of Espírito Santo, 29075-910 Vitória, ES, Brazil.
³ Federal Institute of Espírito Santo, 29192-733 Aracruz, ES, Brazil.

Abstract

In the present work, we report the antioxidant, antimicrobial and cytotoxic activities of quercetin-capped gold nanoparticles (AuNPsQct). The synthesis of AuNPsQct was confirmed by UV-Vis spectroscopy, FTIR and transmission electron microscopy (TEM) analyses. The FTIR spectrum showed the integrity of the quercetin molecules on the nanoparticle surface. The TEM images showed sizes less than 100 nm and a slight spherical shape. The electrostatic stability was confirmed by the zeta potential method. The antioxidant activity of quercetin, evaluated by DPPH, ABTS and nitric oxide free radical scavenging methods, was preserved in the gold nanoparticles, furthermore quercetin-capped gold nanoparticles (IR₅₀ 0.37 µg/mL) demonstrated a higher antioxidant activity than free quercetin (IR₅₀ 0.57 µg/mL) by nitric oxide free radical scavenging method. Strong antifungal activity was observed for Aspergillus fumigatus with concentrations ranging from 0.1 to 0.5 mg/mL. The nanoparticles with quercetin did not exhibit cytotoxicity to human fibroblasts (L929 cells). In conclusion, these results suggest that AuNPsQct, produced by cost-effective method, can act as a promising candidate for different medical applications.

Keywords: Antimicrobial; Antioxidant; Flavonoids; Nanotechnology; Quercetin.