Physicochemical Determinants of Bioactivity in Acacia Gum-Derived Silver Nanoparticles: Enhanced Selective Toxicity Toward MCF-7 Breast Cancer Cells

Silver nanoparticles synthesized using natural polysaccharides have received attention for their biocompatibility and potential selective anticancer activity. In this study, the physicochemical properties and biological activity of silver nanoparticles prepared using gums from Acacia senegal (ASS) and Acacia seyal (ASY) were compared. The gums were analyzed to determine their physicochemical characteristics and used as natural reducing and stabilizing agents in nanoparticle synthesis. The resulting nanoparticles were characterized using UV–visible spectroscopy, FTIR, dynamic light scattering, and zeta potential analysis. Their cytotoxicity was evaluated in MCF-7 breast cancer cells and HEK-293 normal cells using MTT assay, flow cytometry, and intracellular reactive oxygen species (ROS) measurement. Both gums showed properties consistent with Gum Arabic, with a higher protein content in ASS. ASS-derived nanoparticles were smaller and had greater colloidal stability. Both formulations reduced MCF-7 cell viability in a dose-dependent manner, with lower IC₅₀ values observed for the ASS-based nanoparticles. Apoptosis induction was associated with increased ROS generation. Limited cytotoxicity toward HEK-293 cells resulted in favorable selectivity indices. Acacia gum–mediated silver nanoparticles demonstrate selective anticancer activity, and gum composition significantly influences nanoparticle stability and bioactivity, supporting their potential application in breast cancer nanotherapy.