Phytochemical-capped silver nanoparticles from the medicinal plant Embelia laeta disrupting 3D tumorspheres and inducing ROS-mediated apoptosis in MCF-7 breast cancer cells

Plant-based green nanotechnology provides a promising strategy that integrates phytochemicals with metallic nanoparticles for targeted cancer therapy. In this study, silver nanoparticles (Eml-AgNPs) synthesized using Embelia laeta (L.) Mez. leaf extract were investigated for their anticancer potential. The Eml-AgNPs were spherical, crystalline, and averaged 13.4 ± 4.6 nm in size, as confirmed by UV–Vis spectroscopy (absorption peak at 453 nm), XRD, FTIR, and TEM analyses. UPLC-QToF-MS profiling revealed 13 bioactive molecules bound to the nanoparticle surface, contributing to their stability and anticancer efficacy. Eml-AgNPs demonstrated potent, concentration-dependent cytotoxicity against HepG2, AGS, MCF-7, and MKN45 cancer cell lines, with IC₅₀ values ranging from 0.78 µg/mL to 1.67 µg/mL. In 3D tumorsphere cultures, treatment with Eml-AgNPs (2–5 µg/mL) significantly disrupted spheroid morphology and cellular cohesion. Mechanistic studies indicated ROS-mediated apoptosis, evidenced by a 36.7% increase in Annexin V-FITC-positive cells (p < 0.01) and a 32.7% elevation in ROS generation following treatment with 5 µg/mL Eml-AgNPs (p < 0.01). Furthermore, expression of pro-apoptotic genes including CASP8, CASP9, GADD45 , and BAX was significantly upregulated. Collectively, these findings highlight the potential of Eml-AgNPs as a green nanotherapeutic platform, leveraging phytochemical synergy to induce oxidative stress-driven apoptosis in cancer cells. Further in vivo studies are needed to confirm the efficacy and safety of Eml-AgNPs for potential biomedical applications.