Oxidative damage as a toxicity mechanism of silver bionanoparticles in human trophoblasts

BUSTOS PAMELA; GOMEZ DIEGO SEBASTIAN; QUINTEROS MELISA; ORTEGA MARIA GABRIELA; PAEZ PAULINA; GUIÑAZÚ NATALIA

Mar del Plata

Congreso; LXIII Reunión conjunta SAIC SAI SAFIS; 2018

Sociedades SAIC SAI SAFIS

Within the nanomaterials, the metal nanoparticles have gained a great popularity due to their potential antimicrobial activity. Silver nanoparticles (AgNPs) biosynthesized by metal-reducing culture supernatant of Pseudomonas aeruginosa, have demonstrated an important antibacterial activity. Recently we showed that AgNPs are cytotoxic for human trophoblasts. The aim of this study was to deepen the mechanism of toxicity of these nanoparticles in the human trophoblast.HTR8/SVneo cell line was exposed for 6 and 24 h at different concentrations of AgNPs (0.3-1.5 pM). Cell viability, ROS production and endogenous defenses (glutathione content (GSH), catalase (CAT), superoxide dismutase (SOD) and glutathione s-transferase (GST) activities) were determined. Biomarkers of macromolecules oxidative damage were evaluated, for protein oxidation (AOPP method) and genotoxic damage (comet alkaline assay).The exposure of HTR8/SVneo cells to AgNPs produced a decrease in cell viability (CI50 for 6h and 24 h were 1.21 pM and 0.81 pM respectively). All the AgNPs concentrations evaluated induced an increase in ROS production and GSH content. The antioxidant enzymes SOD and CAT increased the activity at the highest concentrations assayed (1.5 pM at 6 h and 0.75-1.5 pM at 24 h). While GST activity, a detoxifying enzyme, decreased after AgNPs treatment. Regarding oxidative damage to biomolecules an increase in protein oxidation and genotoxic damage were observed in cells exposed to AgNPs at the highest concentrations assayed. To elucidate whether oxidative stress is a toxicity mechanism triggered by AgNPs toxicity trophoblast cells were preincubated with the antioxidant NAC (N-acetylcysteine, 2 mM). The treatment with NAC reverted cell death, protein oxidation and genotoxic damage.Therefore, the AgNPs biosynthesized by P. aeruginosa are cytotoxic to human trophoblast cells and oxidative imbalance would be the toxicity mechanism involved in cell death and macromolecule damage triggered by these nanoparticles