Green synthesis and characterization of silver nanoparticles from Alpinia purpurata with their anti-angiogenic potential

Abstract The growing interest in environmentally friendly nanomaterials has increased the use of plant-based approaches for the synthesis of silver nanoparticles, offering a sustainable alternative to conventional chemical methods. Although plant-mediated silver nanoparticles have been widely investigated for their diverse biological activities, their anti-angiogenic potential remains comparatively less explored, particularly for Alpinia purpurata . Previous studies on Alpinia purpurata mediated silver nanoparticles have mainly focused on antimicrobial, cytotoxic, larvicidal, and photocatalytic properties, leaving their potential to regulate angiogenesis insufficiently investigated. In the present study we aimed to synthesize silver nanoparticles using an aqueous leaf extract of A. purpurata through a green synthesis approach and evaluate their physicochemical characteristics and anti-angiogenic potential. The green synthesis of silver nanoparticles was initially indicated by a visible colour change from pale yellow to brownish. The synthesized nanoparticles were characterized using UV–Visible spectroscopy, Dynamic Light Scattering, Zeta potential analysis, Field Emission Scanning Electron Microscopy, Energy Dispersive X-ray analysis, Fourier Transform Infrared spectroscopy, and X-ray Diffraction to determine their optical properties, particle size, surface charge, morphology, elemental composition, functional groups, and crystalline nature. The synthesized silver nanoparticles exhibited a surface plasmon resonance peak at 440 nm, with an average hydrodynamic size of 68.02 nm, a polydispersity index of 0.237, and a zeta potential of − 20 mV. FESEM analysis revealed predominantly cuboidal morphology with an average particle size of 25 nm, while EDX confirmed elemental silver at 64.36%. FTIR analysis identified hydroxyl (–OH), alcohol, carbonyl (C = O), amide, carboxylate (COO⁻), and C–O functional groups, suggesting their involvement in the reduction and stabilization of the nanoparticles. XRD analysis confirmed the crystalline face-centered cubic structure of the synthesized silver nanoparticles. The anti-angiogenic activity was evaluated using the Hen's Egg Test–Chorioallantoic Membrane assay, which demonstrated a significant reduction in total vessel length, vessel density, branching points, and vascular network formation following silver nanoparticles treatment, indicating pronounced anti-angiogenic activity. Overall, the findings demonstrate that A. purpurata leaf-mediated silver nanoparticles possess desirable physicochemical characteristics and significant anti-angiogenic activity, providing evidence for their potential as eco-friendly nanomaterials for further investigation in biomedical applications involving angiogenesis.