Abstract
<title>Abstract</title> <p> Green synthesis of silver nanoparticles (AgNPs) using medicinal plants provides a sustainable route for producing bioactive nanomaterials. In this study, aqueous leaf extract of <italic>Solanum aethiopicum</italic> was employed as a reducing and capping agent for the biosynthesis of AgNPs, which were subsequently characterised and evaluated for their <italic>in vitro</italic> antioxidant activity. Nanoparticle formation was confirmed by a visible colour change and a characteristic surface plasmon resonance band at approximately 420 nm. FTIR analysis indicated the involvement of hydroxyl, carbonyl, amine, aromatic and ether-containing phytochemicals in nanoparticle reduction and stabilisation. TEM showed predominantly spherical nanoparticles with representative diameters of approximately 9.22 and 12.54 nm, while XRD confirmed crystalline face-centred cubic silver with an average crystallite size of approximately 16.5 nm. The biosynthesised AgNPs inhibited malondialdehyde formation by 94.48–96.07%, with calculated inhibition values numerically higher than those obtained for ascorbic acid under the same assay conditions. The available biochemical data also showed concentration-associated SOD and CAT assay responses, with the highest values observed at 6 mg mL⁻¹, together with a concentration-associated increase in GSH response across the tested concentrations. Because replicate-level data were unavailable, these findings were interpreted descriptively rather than as statistically confirmed treatment effects. Collectively, the findings show that <italic>S. aethiopicum</italic> -derived AgNPs are phytochemically capped, crystalline nanostructures that markedly inhibited lipid peroxidation and produced concentration-associated SOD, CAT and GSH assay responses under the experimental conditions. These results support further investigation in cellular, toxicological and in vivo models relevant to oxidative stress. </p>