Selenium release during the simulated gastrointestinal digestion and antioxidant activity of selenium nanoparticles stabilized by Grifola frondosa polysaccharides and gallic acid conjugates

In the study, Grifola frondosa polysaccharides (GFPs) and gallic acid (GA) were utilized to synthesize selenium nanoparticles (GFPs-GA-SeNPs) through a redox reaction involving sodium selenite and ascorbic acid. The morphological changes of GFPs-GA-SeNPs and their antioxidant activities during simulated gastrointestinal digestion were investigated. The results revealed that the antioxidant capacity of GFPs-GA-SeNPs was significantly enhanced compared to SeNPs and GFPs-SeNPs, with IC₅₀ values for scavenging DPPH, superoxide anion, and hydroxyl radical of 0.45, 0.55, and 0.63 mg/mL, respectively. In addition, GFPs-GA-SeNPs showed a two-stage release pattern in in vitro digestion and had a stronger selenium release capacity. At the cellular level, oxidative stress and apoptosis were aggravated in the model group compared with the control group. Interestingly, compared with SeNPs and GFPs-SeNPs, GFPs-GA-SeNPs can more effectively restore mitochondrial membrane potential, reduce ROS levels, and improve apoptosis. Besides, GFPs-GA-SeNPs can up-regulate the expression of Nrf2 protein ( p  < 0.05) which can induce the expression of HO-1, SOD, GSH-Px, CAT, decrease the MDA content. Moreover, GFPs-GA-SeNPs can downregulate NF-κB protein, which can decrease the expression of TNF-α and increase the expression of IL-10. GFPs-GA-SeNPs demonstrated exceptional antioxidant activity and could benefit various industries, including food and health products, and have enormous potential application values.