Abstract
The increasing demand for eco-friendly and biologically active nanomaterials has emphasized the need for sustainable nanoparticle synthesis methods. In this study, zinc oxide nanoparticles (ZnO NPs) were synthesized using Atropa belladonna root extract and evaluated for their biological efficacy. Phytochemical screening confirmed the presence of alkaloids, saponins, phenols, flavonoids, and diterpenes. UV-Vis spectroscopy indicated the involvement of phytoconstituents in NP reduction and stabilization, with a characteristic absorption peak at 376 nm and a bandgap energy of 3.30 eV. Structural and morphological characterization via FT-IR, XRD, and FESEM revealed the presence of functional groups, a hexagonal wurtzite crystalline structure, and spherical particles (20-60 nm) with an average crystalline size of 27.9 nm. EDX analysis confirmed the elemental purity of Zn and O. In antioxidant assays, the green-synthesized ZnO NPs exhibited superior activity compared to the crude extract, with lower IC50 values for DPPH (437.47 μg/mL), ABTS (486.31 μg/mL), FRAP (717.97 μg/mL), and TAC (394.86 μg/mL). The root extract showed moderate antibacterial activity in a concentration-dependent manner, with maximum inhibition at 1000 mg (22 ± 0.5 mm against E. coli and S. aureus, and 20 ± 1.5 mm against P. aeruginosa). In contrast, ZnO NPs exhibited significantly stronger antibacterial effects even at lower concentrations, producing inhibition zones of 30 ± 1.0 mm against E. coli, 30 ± 0.5 mm against S. aureus, and 30 ± 1.0 mm against P. aeruginosa at 100 mg/mL. These results confirm that ZnO NPs possessed broad-spectrum antibacterial activity with superior efficacy over the crude extract against both Gram-positive and Gram-negative bacteria. Insecticidal bioassays demonstrated 99 ± 0.5 % mortality in Drosophila melanogaster and extended development time (12 ± 1.3 days). Cytotoxicity assays against PC-3 cells revealed significant anticancer activity, with GI50 values of 172.36 μg/mL (extract) and 10.438 μg/mL (ZnO NPs), accompanied by apoptotic features and elevated ROS generation (32.6 %). These results highlight the multifunctional potential of A. belladonna-derived ZnO NPs in therapeutic and agricultural applications.
