Nanoparticles and their synthesis and application have been widely studied in recent years. Silver nanoparticles are one of the most fully studied materials. Nanoparticles are produced in many ways, including physical and chemical methods such as microwave treatment, chemical reduction, photochemical methods, and biological synthesis methods. Silver nanoparticles have a significant effect on the living cells of both prokaryotes and eukaryotes. The technology for biological production of nanoparticles is simple and effective. The aim of this study was to develop a method for producing green nanoparticles using eggplant extract. UV-Visible spectral analysis and the X-ray diffraction (XRD) assay were used for the characterization of nanoparticles. The size of the nanoparticles was calculated based on the Debye–Scherrer equation. It was determined that a silver nitrate concentration of 1 mM was the most effective for the green synthesis of nanoparticles using eggplant extract. The resulting particles were optimized and the phytochemical properties of eggplant silver nanoparticles and the effectiveness of their use in therapy were assessed. The ability of the synthesized nanoparticles to remove free radicals was assessed and the most effective concentration of antioxidants was determined. It was found that the most effective concentration was 200 ppm when using the method of inhibiting DPPH oxidation in comparison with such a widely used antioxidant as ascorbic acid. Thus, silver nanoparticles were synthesized from eggplant extract, which effectively prevented oxidation, which can be considered as a simple, inexpensive and effective way to obtain green nanoparticles. The study showed that eggplants are a cheap raw material for producing silver nanoparticles using green synthesis, which have the function of antioxidant protection and are able to remove free radicals. The work carried out shows the advantages of green synthesis of nanoparticles for a clean and lower cost production of food additives to improve the quality of life of people.