Green-synthesized silver nanoparticles: antifungal and cytotoxic potential for further dental applications

Abstract

Fungal infections caused by Candida albicans (C. albicans) are one of the most prevalent types of oral disorders in the elderly. It has been reported that drug resistance to fungal pathogens poses a severe risk to global healthcare systems and public health. Therefore, the goal of this work is to investigate the cytotoxic and antifungal properties of silver nanoparticles (AgNPs) produced using three different natural extracts: Berzelia lanuginose, Helichrysum cymosum, and Searsia crenata. According to the UV-Vis results, the synthesized AgNPs via B. lanuginose, H. cymosum, and S. crenata show surface plasmonic resonance (SPR) peaks at 430, 440, and 428 nm, respectively. HR-TEM revealed different shapes for the nanoparticles within the size ranges of 16-20, 31-60, and 57-72 nm for B. lanuginose, H. cymosum, and S. crenata, respectively. Using a human oral fibroblast cell line, the cytotoxicity of both AgNPs and plant extracts was tested at concentrations of 0.007, 0.012, 0.025, and 0.062 mg/mL (buccal mucosa fibroblasts). The antifungal activity showed growth inhibition zones of approximately 18 mm, 18.67 mm, and 18.33 mm for the AgNPs conjugated with B. lanuginose, H. cymosum, and S. crenata, respectively. For the studied samples, the minimum inhibitory concentration (MIC50) was less than 0.015 mg/mL. The AgNPs exhibited antifungal activity that was concentration- and size-dependent. The results of this study offer new insights into the cytotoxicity and antifungal activity of the green-synthesized AgNPs.