Anti-Angiogenic Properties of Silver Nanoparticles Synthesized from Clerodendrum schmidtii Leaf Extract

Objectives: This study aimed to synthesize silver nanoparticles (AgNPs) using ethanol leaf extracts of Clerodendrum schmidtii and to evaluate their anti-angiogenic activity as a potential basis for cancer-related applications. Methods: Freeze-dried leaves were extracted with ethanol, and AgNPs were synthesized under optimized conditions (1:1 extract-to-AgNO₃ ratio, pH 11, 80 °C, 30 min). The resulting nanoparticles were characterized using ultraviolet-visible (UV-Vis) spectrophotometry, Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), dynamic light scattering (DLS), and zeta potential analysis. Anti-angiogenic activity was assessed using the chorioallantoic membrane (CAM) assay with proper controls and replication. Findings: The CS-AgNPs had an average particle size of 54.3 ± 15.7 nm and a zeta potential of -77.6 ± 6.6 mV, indicating excellent colloidal stability. UV-Vis analysis showed a peak at 403 nm. The FTIR analysis revealed the functional groups (-OH, C=O, C=C, C-N) associated with phytochemical-mediated reduction and capping. SEM analysis showed predominantly spherical particles. In the CAM assay, CS-AgNPs produced a dose-dependent inhibition of angiogenesis, reaching a 73.78 ± 2.34% reduction in vascular branching at 500 ppm extract equivalent (50 ppm AgNPs). This inhibitory effect was significantly greater than the 54.71 ± 3.31% inhibition observed with the crude extract alone. Nonlinear regression confirmed an IC50 of 249.4 ± 7.7 ppm. Novelty: This study reports, for the first time, the green synthesis of AgNPs using C. schmidtii and demonstrates their significant anti-angiogenic activity, highlighting their potential as plant-derived candidates for anticancer nanomedicine, pending further in vivo validation. Keywords: Clerodendrum schmidtii, Silver Nanoparticles, Green Synthesis, Anti-angiogenic Activity, Chorioallantoic Membrane Assay, Dose-dependent Inhibition