Phytogenic Silver and Copper Nanoparticles from Morus nigra L. Leaf as Multifunctional Agents: Antioxidant, Antidiabetic, Antimicrobial, and Anticancer Potency

The growing need for eco-friendly nanomaterials has directed attention toward plant-based green synthesis as a sustainable approach for biomedical applications. This study reports the biosynthesis of silver (YAgNPs) and copper nanoparticles (YCuNPs) using Morus nigra L. leaf extract and evaluates their multifunctional properties. The nanoparticles were produced under alkaline aqueous conditions, and their crystalline nature and nanoscale morphology were confirmed by standard structural and elemental analyses. Both YAgNPs and YCuNPs exhibited enhanced antioxidant capacities compared to the crude extract. YAgNPs showed the highest ferric reducing antioxidant power (250.33 mg FeSO₄/g), while YCuNPs demonstrated superior DPPH radical scavenging activity (114.12 mg AAE/g). In antidiabetic assays, YAgNPs strongly inhibited α-amylase (IC₅₀ = 112.02 μg/mL) and α-glucosidase (IC₅₀ = 38.27 μg/mL), approaching the potency of acarbose. Antimicrobial analysis revealed distinct activity profiles: YAgNPs were highly effective in broth cultures with low MIC and MBC values (0.09–0.18 mg/mL against B. subtilis and E. coli), whereas YCuNPs achieved larger inhibition zones in diffusion assays. Checkerboard testing confirmed synergistic interactions between nanoparticles and antibiotics, with FICI values ≤0.5 against E. faecium, E. coli, and P. aeruginosa, highlighting their ability to enhance antibiotic efficacy. YAgNPs exhibited notable cytotoxic effects against HeLa and HCT116 cancer cell lines, with IC₅₀ values of 9.84 and 6.83 μg/mL, respectively. In contrast, YCuNPs displayed weaker anticancer activity. Overall, these findings demonstrate that M. nigra derived nanoparticles combine antioxidant, antidiabetic, antimicrobial, and anticancer activities with synergistic antibiotic-enhancing effects, underscoring their potential as sustainable, multifunctional therapeutic agents.