GREEN-SYNTHESIS OF SILVER NANOPARTICLES USING N. GLAUCA LEAVES EXTRACT: CHARACTERIZATION AND EVALUATION OF ANTIOXIDANT, ANTIBACTERIAL AND CYTOTOXIC ACTIVITIES

Objective: In this study, silver nanoparticles (NG-AgNPs) were synthesized and characterized using Nicotiana glauca (N. glauca) leaves extract and their antibacterial and anticancer properties were evaluated. Methods: An Extract of N. glauca leaves was obtained via soxhlet and maceration techniques using water and ethanol as solvents, and the total phenolic content (TPC) and total flavonoid content (TFC) were determined.Water-maceration extract was used to synthesizeNG-AgNPs which were characterized using Ultraviolet-Visible (UV-Vis) spectroscopy, particle size, zeta potential, polydispersity index (PDI), and stability. Antibacterial activity was tested against Staphylococcus aureus and Pseudomonas aeruginosa, and cytotoxicity was assessed in colorectal (HT-29), lung (A549), and breast (MCF-7) cancer cell lines using an MTT assay. Results: NG-AgNPs displayed a UV-Vis peak at 440.50 nm, with an average size of 188–280 nm, zeta potential of -29.6 mV, and PDI of 0.216, indicating stability. They demonstrated superior antimicrobial activity with inhibition zones of 24.6 mm (S. aureus) and 20.6 mm (P. aeruginosa) and Minimum Inhibitory Concentration (MIC) values of 0.15 mg/ml and 0.5 mg/ml, respectively. Cytotoxicity studies revealed IC50 values of 2.517µg/mL (HT-29), 25.11 µg/mL (A549), and 24.53µg/mL (MCF-7), while showing no toxicity toward normal endothelial cells (EA.hy926), highlighting their selective cytotoxicity against cancer cells. Conclusion: These results suggest that the prepared NG-AgNPs exhibit potent antibacterial and anticancer properties with enhanced efficacy compared to the crude extract, making them promising candidates for therapeutic applications.