Green synthesis, characterization, and anticancer activity of silver nanoparticles via Pulsatilla koreana root extract

A green synthesis route for silver nanoparticles (Pk-AgNps) has been successfully developed using <i>Pulsatilla koreana</i> root extract as both reducing and stabilizing agent. Optimal synthesis conditions of 80 °C for 60 min produced nanoparticles characterized by a distinct surface plasmon resonance (SPR) peak at 464 nm. Comprehensive characterization through field-emission transmission electron microscopy (FE-TEM), X-ray diffraction analysis (XRD), and Fourier transform infrared analysis (FTIR) confirmed the formation of quasi-cubic, polycrystalline nanoparticles in the size range of 80-100 nm, stabilized by phytochemical constituents from the extract. The synthesized Pk-AgNps demonstrated significant bioactivities including concentration-dependent antioxidant capacity and potent antibacterial effects against both Gram-positive and Gram-negative bacteria. Furthermore, the nanoparticles exhibited selective cytotoxicity against human cancer cell lines, with particular efficacy against A549 lung cancer cells. Mechanistic studies revealed that this anticancer activity involves Reactive oxygen species (ROS)-mediated apoptosis through suppression of the EGFR/MAPK signaling pathway and regulation of Bcl-2/Bax expression. These multifunctional properties of Pk-AgNps as a promising candidate for further exploration in functional food and biomedical applications.