SÍNTESE VERDE E CARACTERIZAÇÃO DE NANOPARTÍCULAS DE PRATA UTILIZANDO PRÓPOLIS VERMELHA AMAZÔNICA PROVENIENTE DO PARÁ

Abstract

Propolis is a resinous material produced by honeybees of the species Apis mellifera, widely used in folk medicine due to its antioxidant, anti-inflammatory, and antimicrobial properties. In recent years, its potential has been explored in nanotechnology, especially in the green synthesis of metallic nanoparticles, such as silver nanoparticles (AgNPs), which exhibit broad antimicrobial activity and the ability to interact with microbial structures. Given the increasing bacterial resistance to conventional bacteria, the integration of propolis and green nanotechnology emerges as a promising strategy for the development of new antimicrobial agents of natural origin. Therefore, this study carried out the green synthesis of silver nanoparticles using the hydroalcoholic extract of Amazonian red propolis as a reducing and stabilizing agent for silver ions. The Amazonian red propolis was evaluated for its reducing potential through the determination of total phenolic compounds, flavonoids, and antioxidant activity. The extract showed a high content of total phenolic compounds (228.6 ± 11.3 mg GAE/g) and flavonoids (131.9 ± 5.5 mg QE/g), in addition to significant antioxidant activity in the DPPH assay (EC50 = 22.2 µg/mL). Chemical characterization by HPLC revealed the presence of isoflavonoids such as calicosine, formononetin, and vestitol, compounds associated with the reducing capacity of the extract. Based on these properties, the green property of silver nanoparticles with red propolis (nAgPVA) was developed. The synthesis conditions were optimized using the Box–Behnken Design (BBD) experimental design. The formation of the nanoparticles was monitored by UV-Vis spectroscopy, in which synthesis 3 showed a plasmonic absorption band at approximately 425 nm after 24 h. Physicochemical characterization by dynamic light scattering (DLS) indicated an average hydrodynamic diameter of 91.3 to 534.3 nm, while a zeta potential of −4.7 to −27.2 mV promotes moderate electrical stability of the dispersions. In microbiological assays, nAgPVA showed antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa strains, with minimum inhibitory concentrations ranging from 15.3 to 49.3 mg/L. Furthermore, cytotoxicity assessment in GM-07492ª fibroblasts did not indicate cellular cytotoxicity under the tested conditions. The results demonstrate that Amazonian red propolis constitutes an efficient natural matrix for supplying nanoparticles with antibacterial potential and low cytotoxicity to normal cells, standing out as a sustainable alternative in combating bacterial resistance.