A comparative analysis of Fagonia indica extracts and green synthesized nanoparticles for the determination of antioxidant potential

This investigation explores the protective effect of Fagonia indica against oxidative damage by comparing its aqueous and methanolic extracts with their corresponding green-synthesized silver nanoparticles (AgNPs). AgNPs were synthesized using an eco-friendly green synthesis approach, and samples were then examined through UV-Vis spectroscopy, FTIR spectroscopy, zeta potential analysis, SEM, and XRD. The antioxidant capacity of the plant was calculated using DPPH radical scavenging, Total Antioxidant Capacity (TAC), and Total Reducing Power (TRP) assays. All the samples showed mild DPPH scavenging potential as compared to standard (ascorbic acid). The methanolic nanoparticles (FIMNps) had the maximum DPPH inhibition of 18.93 ± 1.51 % at 100 μg/mL, while the methanolic extract (FIME) achieved 16.32 ± 1.42 % inhibition. In contrast, aqueous nanoparticles (FIAqNps) showed 0% DPPH inhibition, while aqueous extract (FIAqE) had 11.28 ± 1.53% inhibition. TAC values (as determined by absorbance units, a.u.) were highest in FIMNps (0.610 ± 0.12 a.u.), followed by FIAqNps (0.537 ± 0.21 a.u.), FIAqE (0.462 ± 0.11 a.u.) and FIME (0.221 ± 0.05 a.u.). In the TRP assay, FIME exhibited the highest reducing power (2.945 ± 0.25 a.u.), followed by FIAqNps (2.880 ± 0.21 a.u.), FIMNps (2.718 ± 0.31 a.u.) and FIAqE (2.548 ± 0.67 a.u.). Zeta potential values indicated moderate stability with - 11.8 mV for FIAqNps and + 1.72 mV for FIMNps. SEM images revealed non spherical nanoparticles, and XRD confirmed their crystalline nature. These findings demonstrate that green-synthesized AgNPs, particularly from methanolic extracts, significantly enhance antioxidant activity and offer potential for therapeutic applications against oxidative stress-related disorders.