Biosynthesis and Multifaceted Characterization of Breynia nivosa-Derived Silver Nanoparticles: An Eco-Friendly Approach for Biomedical Applications

This study presents an environmentally friendly synthesis of stable silver nanoparticles (Ag-NPs) using the methanolic extract of Breynia nivosa. Initial phytochemical analysis of the extract revealed the presence of alkaloids, flavonoids, glycosides, saponins, and tannins. Further characterization through high-performance liquid chromatography (HPLC) and gas chromatography–mass spectrometry (GC-MS) analyses identified a diverse array of bioactive compounds, including hydroquinone, stearic acid, neophytadiene, 9,12-octadecadienoic acid (Z,Z), methyl ester, and others. The addition of B. nivosa methanolic extract to an AgNO3 solution resulted in a color change, confirming the green synthesis of Ag-NPs through the reduction of AgNO3, as made evident by ultraviolet–visible (UV–vis) spectroscopy. X-ray diffraction (XRD) analysis provided valuable insights into the crystal structure, and scanning electron microscopy (SEM) analysis visualized the predominantly spherical shape of the Ag-NPs. However, the zeta (ζ)-potential and dynamic light scattering (DLS) analyses confirmed the stability and nanoscale dimensions of the synthesized Ag-NPs. Meanwhile, Fourier transform infrared (FT-IR) spectra exhibited peaks indicative of various functional groups, including carboxylic acids, phenols, alkanes, and isocyanates. These functional groups played a crucial role in both the reduction and capping processes of the Ag-NPs. The study further explored the antioxidant activity, cytotoxicity, acetylcholinesterase inhibition, and α-amylase inhibition activities of the Ag-NPs of the B. nivosa extract, demonstrating their potential for biomedical and therapeutic applications. In conclusion, this environmentally sustainable synthesis of Ag-NPs from the B. nivosa extract, enriched with bioactive secondary metabolites detected through HPLC and GC-MS analysis, holds promise for diverse applications in the burgeoning field of green nanotechnology.