Green synthesis of silver nanoparticles using Morus nigra leaf extract and their mechanistic insights into antimicrobial and anticancer effects

This study reports the preliminary biological evaluation of glucose-capped silver nanoparticles synthesized using an aqueous leaf extract of Morus nigra . LC-MS analysis of the methanolic extract provided a preliminary metabolite profile of the plant, confirming the presence of bioactive secondary metabolites. The silver nanoparticles were characterized using various analytical techniques, such as UV-Vis Spectroscopy, FTIR, FESEM, TEM, and DLS/Zeta. 2,2-diphenyl-1-picrylhydrazyl (DPPH) and phosphomolybdate assays demonstrated significantly higher antioxidant potential of GC-AgNPs than aqueous leaf extract. GC-AgNPs reported 57% inhibition (IC 50 ≈ 65 μg/mL) and a total antioxidant capacity of approximately 446.15 mg AAE/g at 250 μg/mL in the DPPH and phosphomolybdate assays, respectively. The selective antimicrobial dosing against Escherichia coli and Staphylococcus aureus was determined based on delivery modes. A clear zone of inhibition of 8.33 mm and 12.66 mm against E. coli was reported in the disc diffusion method. Contrastingly, S. aureus showed inhibition zones of 14 mm and 16 mm in the well diffusion method. The cytotoxic evaluation against SiHa cervical cancer cells using the MTT assay revealed an IC 50 value of 52 μg/mL for nanoparticles compared to aqueous leaf extract (81 μg/mL). The findings suggest a possible intracellular delivery mechanism; however, this remains hypothetical and requires further validation, including nanoparticle uptake, oxidative-stress pathways, intracellular localization, and others.