Genotoxicity assessment of laser-synthesized silver nanoparticles with Salvia officinalis aqueous extract

Abstract

In recent years, silver nanoparticles (AgNPs) have gained considerable attention due to their potent antimicrobial, anti-inflammatory, and wound healing properties. However, despite their therapeutic potential, the biosafety profile of AgNPs remains a concern, as these nanoparticles can penetrate cellular membranes and potentially induce cytotoxic or genotoxic effects. Laser “green” synthesis is based on a process of laser ablation of metal target immersed in liquid (PLAL), and represents one of the cleanest synthesis methods for AgNPs, as it eliminates the need for toxic reducing agents. The use of natural compounds could enhance synthesis by enabling nanoparticle stabilization and mitigating their toxicity. Among them, Salvia officinalis (sage) could be of specific importance, as it possesses anti-inflammatory, radical-scavenging, and antigenotoxic properties. In this study, we evaluated the genotoxic potential of laser-synthesized AgNPs prepared in sage aqueous leaf extract (Sage-AgNPs) versus those synthesized via pulsed laser ablation in deionized water (Dw-AgNPs). AgNPs synthesis was performed by picosecond laser system Nd:YAG EKSPLA SL 212/SH/FH, and their physico-chemical characterization was performed. The cytokinesis-block micronucleus assay was used to assess micronuclei (MN) frequency and proliferation index (CBPI) in human peripheral blood mononuclear cells upon 24-hour treatment with both AgNPs, at the concentrations of 2.5, 5 and 10 μg/mL. The results showed that Dw-AgNPs induced concentration-dependent MN increase, statistically significant at the concentrations of 5 and 10 μg/mL, while simultaneously decreasing CBPI. In contrast, MN frequency after treatment with Sage- AgNPs was in the range of the untreated control for concentrations of 2.5 and 5 μg/mL, without affecting CBPI. The highest tested concentration led to a minor, albeit insignificant MN frequency increase and significantly reduced proliferation. These findings suggest that laser-synthesized AgNPs with sage aqueous extract reduce genotoxic effects, highlighting the potential of sage extract in PLAL synthesis as a safe alternative for AgNPs synthesis for biomedical applications.