Green synthesis of silver nanoparticles: understanding biological activities – anticancer, antimicrobial, and plasmid DNA cleavage properties through reactive oxygen species release†

This study is designed to explore the preparation, characterization, biological impacts, and DNA degradation abilities of green synthesized NPs. The UV-visible analysis confirms the reduction of Ag along with pH. FTIR studies are used to determine the functional groups involved in the reduction reaction. Moreover, HR-TEM and XRD reveal the morphology and crystal plane of the NPs. Further, the XPS study confirms the elemental analysis and oxidation state of the metal. Biological studies were conducted to assess the effectiveness of NPs, including their antibacterial, anticancer, and DNA degradation activities. According to the acquired data, Ag-NPs show a strong antibacterial action against both Gram-positive and Gram-negative bacteria. Additionally, Ag-NPs demonstrate cytotoxicity against pBR322 DNA degradation and breast cancer cell lines at 40 and 50 μg mL⁻¹, respectively. Herewith, we report a simple synthesis of Ag-NPs with benign, environmentally safe, biological reduction by using natural biomolecules. The synthesized Ag-NPs have a size around 10 nm and the ability to produce ROS under visible light irradiation. Finally, Ag-NPs exhibit cytotoxicity, including intracellular ROS generation, cell death, loss of mitochondrial potential, and DNA fragmentation on breast cancer cells. Importantly, Ag-NPs show nuclease activity.