Myricitrin-Mediated Biogenic Silver Nanoparticle Synthesis, Characterization, and its Antioxidant, Anticancer, and DNA Cleavage Activities

Introduction: Myricitrin (MY) is a potent antioxidant flavonoid that has recently gained research interest due to its wide applications in food, cosmetics, and medicine. Objective: The current work reports MY, its isolation and characterization from Eugenia uniflora leaves, and green synthesis with AgNO₃ to afford myricitrin-based silver nanoparticles (MY-Ag NPs). Materials and Methods: The biosynthesized nanoparticles (NPs) were characterized using UV, field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), High-resolution transmission electron microscopy (HRTEM) and Dynamic light scattering (DLS) methods. Antioxidant, anti-cancer, and DNA cleavage activities were based on standard in vitro bioassay methods. Results: The UV-vis absorption peak at 430 nm suggests the formation of silver-based NPs. The FESEM imaging showed spherical-to-cubical shaped MY-Ag NPs with an average size of 45.35 nm. The EDX analysis showed the presence of elemental Ag (89.40%) and N (10.22%), suggesting a successful synthesis. The XRD analysis revealed various peaks at 38.37⁰, 43.56⁰, 63.76⁰, and 77.77⁰, which suggest metallic silver reflections, further establishing the crystallinity of NPs. The MY-Ag NPs inhibited O₂ -, OH-, H₂O₂, and NO free radicals in a dose-dependent manner. At 50 and 80 μg/mL, it demonstrated a better inhibitory effect on OH- radical than L-ascorbic acid. The cytotoxicity (IC₅₀) against human cancer cell lines of the kidney (ACHN) and the liver (HepG2) were 54.21 ± 0.06 μg/mL and 33.36 ± 2.25 μg/mL respectively at 48 h post-treatment. Lastly, at 20 mg/mL for 120 minutes, MY-Ag NPs cleaved DNA, acting as chemical nucleases. This may suggest its capacity to impede cancer cells by cleaving the genome. Conclusion: Therefore, this study has shown that Myricitrinbased Ag NPs possess notable antioxidant and cytotoxicity that can be further exploited in the search for newer anticancer agents.