Assessment of cytotoxicity and immune compatibility of phytochemicals-mediated biosynthesised silver nanoparticles using Cynara scolymus

The study was focused on the phytochemicals-mediated biosynthesis of silver nanoparticles using leaf extracts and infusions from Cynara scolymus. To identify the antioxidant activity and total phenolic content, the 1,1-diphenyl-1-picrylhydrazyl and Folin-Ciocalteau methods were applied, respectively. The formation and stability of the reduced silver ions were monitored by UV-vis spectrophotometer. The particle sizes of the silver nanoparticles were characterised using the dynamic light scattering technique and scanning electron microscope. The phase composition of the obtained silver nanoparticles was characterised by X-ray diffraction. The silver nanoparticles suspension, artichoke infusion, and silver ions were separately tested towards potential cytotoxicity and pro-inflammatory effect using mouse fibroblasts and human monocytes cell line, respectively. The total phenolic content and antioxidant activity of ethanol extract and infusion were found significantly higher as compared to aqueous extract and infusion. The UV-visible spectrophotometric analysis revealed the presence of the characteristic absorption band of the Ag nanoparticles. Moreover, it was found that with the increasing volume of plant extract, the average size of particles was increased. Biocompatibility results evidently showed that silver nanoparticles do not induce monocyte activation, however in order to avoid their cytotoxicity suspension at a concentration <2 ppm should be applied.