Synergistic Antioxidant Activity of Green-Synthesized Iron Oxide Nanoparticles: A Comparative Study of Capparis decidua Phytochemical-Mediated Synthesis and In Vitro Evaluation

Abstract

Oxidative stress is a primary etiological agent in most chronic illnesses, hence the necessities the development of effective antioxidant interventions. In this study, the antioxidant synergy between iron oxide nanoparticles (FeONPs) prepared by the use of a green chemistry method that utilizes aqueous extracts of Capparis decidedua was evaluated, a botanical source rich in polyphenolic compounds. The phyto-mediated reaction used ferric chloride hexahydrate as the metal ion precursor and the bioactives in the plants served as reducing and stabilizing agents. Full physicochemical characterization through ultraviolet-visible spectroscopy depicted typical surface plasmon resonance pinnacles at 242, 385, 422, and 477nm, thus establishing nanoparticle development. Fourier-transform infrared spectroscopy analysis indicates the presence of phytochemical adsorption onto the surfaces of the nanoparticles. The measurements of dynamic light scattering determined a hydrodynamic diameter of 88.5nm and a moderate colloidal stability (zeta potential = -28.3mV). Dose-dependent in vitro antioxidant assessment using DPPH, ABTS, and nitric oxide radical scavenging showed an IC50 of 47.82 ± 1.86, 64.31 ± 0.97, and 68.54 ± 0.79 μg/mL mg/ml, respectively. Notably, FeONPs also exhibited much greater antioxidant activity as compared to the plant extract itself, and this is indicative of synergy, which can be ascribed to the interplay between the phytochemical corona and the nanoparticle core. These findings support green-syntheses FeONPs as attractive options to be used as therapeutic agents in oxidative stress-linked diseases, which have advantages in the aspects of biocompatibility, multifunctional features, and sustainable synthesis.