Biofabrication of Terminalia ferdinandiana-Conjugated Gold Nanoparticles and Their Anticancer Properties

Harnessing nature's chemistry, this study explores the enhanced biomedical potential of Terminalia ferdinandiana Exell (Kakadu Plum) by transforming its aqueous leaf and fruit extracts into bio-inspired gold nanoparticles (AuNPs). The synthesis process was optimized by varying the Au³⁺/extract ratio and pH, with nanoparticle formation verified through UV-visible spectrophotometry, TEM, and DLS analyzes. Kakadu Leaf extract-conjugated AuNPs (AuKLs), synthesized at pH 8 with a 1:25 Au³⁺/extract ratio, produced the smallest and most uniform particles (21.1 nm; PDI 0.17). In contrast, fruit extract alone failed to generate stable nanoparticles, highlighting the pivotal role of leaf phytochemicals as natural reducing and stabilizing agents. Biological evaluations revealed that both the crude leaf extract and AuKLs possessed strong antioxidant capacity, while the AuKLs further exhibited selective anticancer activity effectively inhibiting breast cancer (MCF-7) and human cervical carcinoma (HeLa) cell proliferation without harming normal mammalian breast (MCF10A) cells. A combined 2:1 leaf-to-fruit extract formulation yielded well-stabilized AuNPs (AuKPLs) with biomedical properties comparable to AuKLs, though the fruit extract alone contributed minimally to both nanoparticle formation and biological performance. Overall, this study demonstrates that the phytochemical richness of T. ferdinandiana leaves enables the green synthesis of small, stable, and bioactive gold nanoparticles. The resulting nanoconjugates, AuKLs and AuKPLs, hold considerable promise for future pharmacological and therapeutic applications, bridging traditional plant-based medicine with modern nanotechnology.