Investigation and comparison of the antioxidant properties of crocin and gallic acid-loaded Nanoniosomes

In this study, the antioxidant properties of Crocin nanoniosomes (CRN) and Gallic acid nanoniosomes (GAN) were compared as two active plant-derived compounds with potential pharmaceutical applications. Nanoniosomes were synthesised using the thin-film hydration method, and their physicochemical properties, including particle size, zeta potential, and encapsulation efficiency, were characterised. The antioxidant activities of free Crocin (CR), Gallic acid (GA), and their corresponding nanoniosomes (CRN and GAN) were assessed using DPPH and ABTS radical scavenging assays, with Ascorbic acid used as a reference. Results showed that antioxidant activity was both time- and concentration-dependent, with higher concentrations significantly increasing free radical inhibition. Specifically, CRN exhibited a stronger antioxidant effect (IC50 = 10.4 μg/mL) than free CR (IC50 = 46 μg/mL) after 60 min, as measured by the DPPH method. Similarly, GAN showed greater activity (IC50 = 78 μg/mL) than free GA (IC50 = 125 μg/mL). In the ABTS method, the antioxidant activity of CRN (IC50 = 20.1 μg/mL) was higher than that of CR with (IC50 = 158 μg/mL) at 60 min. The antioxidant activity of GAN (IC50 = 34.1 μg/mL) was almost equal to that of GA. CRN showed higher antioxidant activity than the other compounds in this method. In both assays, nanoniosomes enhanced the antioxidant efficacy of the original compounds. These findings suggest that nanoniosome encapsulation not only preserves but also improves the antioxidant properties of natural compounds, making them promising candidates for pharmaceutical formulations.