Preparation and characterization of Acanthopanax polysaccharides nanoselenium with enhanced stability and antioxidant activity

To address the issue of nanoselenium easily aggregating and becoming inactive, <i>Acanthopanax senticosus</i> polysaccharides were used as a stabilizer to construct <i>Acanthopanax senticosus</i> polysaccharide nanoselenium for potential nutritional applications. ASP-SeNPs were synthesized using a chemical reduction method with ultrasonic assistance, and response surface methodology was used to optimize the preparation conditions to control particle size. The characterization results show that the basic structure of polysaccharides in ASP-SeNPs is retained, and they are mainly bound to nanoselenium through hydrogen bonds or coordination bonds. ASP-SeNPs particle size distribution ranged from 58 to 123 nm, with an average zeta potential of -27.8 mV. A one-month stability test showed that ASP-SeNPs had superior stability compared to conventional SeNPs, remaining stable for 30 days at 4 °C and for 20 days at room temperature (25 °C). Furthermore, ASP-SeNPs exhibited free radical scavenging activity against DPPH (1,1-diphenyl-2-picryl-hydrazyl radical), ABTS [2,2'-Azinobis-(3-ethylbenzthiazoline-6-sulphonate)], and hydroxyl radicals. Their IC₅₀ values were, respectively, 76.789 μg/mL, 74.927 μg/mL, 343.419 μg/mL.