Green-Synthesized Silver Nanoparticles from Medicinal Plants and Their Cytotoxic Activity Against MCF-7 Breast Cancer Cells

Silver nanoparticles (Ag NPs) were synthesized using Salvia officinalis, Mentha piperita, and Thymus vulgaris extracts through a green synthesis approach, and their cytotoxic effects against MCF-7 breast cancer cells were evaluated. Ag NPs were characterized by UV–Vis spectroscopy, SEM–EDX, FT-IR, and ImageJ-based particle size analysis. Cytotoxicity was evaluated by MTT assay at 25, 50, and 100 µg ml⁻¹. UV–Vis spectra showed characteristic surface plasmon resonance peaks at 420–450 nm, confirming Ag NP formation. SEM and ImageJ analyses revealed predominantly spherical nanoparticles with mean sizes of 23.5 ± 9.2, 51.8 ± 17.6, and 59.9 ± 30.0 nm for S. officinalis, M. piperita, and T. vulgaris-derived Ag NPs, respectively. All preparations exhibited concentration-dependent cytotoxicity. At 100 µg ml⁻¹, S. officinalis-derived Ag NPs showed the highest cytotoxicity (90.82%), followed by T. vulgaris (54.41%) and M. piperita (45.62%) (p < 0.001). These findings demonstrate plant-dependent differences in Ag NP characteristics and cytotoxic activity against MCF-7 cells.