Phytochemical-Mediated Synthesis of Gold Nanoparticles Using Annona Muricata Leaf Extract and Their Cytotoxic Effects on Cancer Cells

Annona muricata, commonly known as soursop, graviola, or guanabana, is a fruit tree belonging to the Annonaceae family. This evergreen plant has a long history of traditional use and is primarily found in tropical and subtropical regions worldwide. The fruits and leaves of A. muricata are widely used to create syrups, candies, beverages, ice creams, and shakes. Numerous studies have confirmed the health benefits of this plant, highlighting its anticancer, anticonvulsant, antiarthritic, antiparasitic, antimalarial, hepatoprotective, and antidiabetic properties. Our current analyses have characterized the nanoparticles produced from A. muricata leaves. Transmission Electron Microscopy (TEM) confirmed that these nanoparticles are polydisperse, exhibiting various shapes, including spheres, triangles, and hexagons, with sizes ranging from 20 to 100 nm. The Selected Area Electron Diffraction (SAED) pattern indicated that the nanoparticles have a face-centered cubic (FCC) crystalline structure and are highly pure. Fourier Transform Infrared Spectroscopy (FTIR) analysis identified several functional groups, including O–H, C=O, and C–N. These findings suggest that the phytochemicals in the leaf extract act as both reducing and stabilizing agents during nanoparticle synthesis. Energy Dispersive X-ray Spectroscopy (EDAX) results further confirmed that gold is the predominant element present, validating the successful formation of gold nanoparticles (AuNPs). Fluorescence studies demonstrated strong emission in the visible region, indicating that the synthesized nanoparticles possess good optical properties. This study shows that the phyto-mediated synthesis of gold nanoparticles from A. muricata is a simple, eco-friendly, and cost-effective method. The produced AuNPs exhibit excellent structural stability, significant biological activity, and promising anticancer potential, making them suitable candidates for future applications in nanomedicine, targeted drug delivery, and cancer therapy. Tests of anticancer activity revealed a strong, dose-dependent cytotoxic effect on A549 lung cancer cells, with an IC₅₀ value of 6.8 µg/ml, demonstrating the high effectiveness of the synthesized nanoparticles. Observed morphological changes, such as cell shrinkage, detachment, and reduced cell density, confirmed the induction of cell death. Overall, this study illustrates that Annona muricata-mediated gold nanoparticles possess excellent structural, optical, and biological properties, with significant potential for anticancer applications.