Antiviral and antioxidant properties of green synthesized gold nanoparticles using Glaucium flavum leaf extract

Abstract
Nowadays, nanoparticles such as gold nanoparticles (Au NPs) with specific biophysical characteristics have attracted remarkable attention as innovative options for the diagnosis and treatment of different diseases. In the present research, Au NPs were green synthesized using the Glaucium flavum leaf extract as an inexpensive and eco-friendly synthesis method. Then, the physicochemical properties were characterized by transmission electron microscopy (TEM), dynamic light scattering method (DLS), scanning electron microscopy (SEM), X-ray diffraction (XRD), Ultraviolet–visible absorption spectroscopy (UV–Vis), Zeta potential, and Fourier transform infrared (FTIR) spectroscopy. Afterwards, the antioxidant capacity was tested and antiviral activity against influenza virus was evaluated by applying TCID50 and PCR assays. The nanoparticles cytotoxicity was tested using the MTT method. The shape and size of Au nanoparticles were modulated by varying leaf concentrations with face-centered cubic (FCC) structure. At higher concentrations, long-time stable spherical nanoparticles were obtained with a mean particle size of 32 nm and low aggregation degree that could simply combine with various bioactive compounds. The outcomes exhibited effective antiviral and antioxidant activities with low cytotoxicity and acceptable biocompatibility of green synthesized Au NPs. The aim of the present study was to develop a potentially environmentally friendly nanoplatform with excellent antiviral and antioxidant functions and acceptable biocompatibility for promising biomedical applications in the future.