Preparation and In Vitro Bioactivity Evaluation of Ganoderma lucidum Melanin-Stabilized Selenium Nanoparticles

Selenium nanoparticles (SeNPs), a highly promising candidate as a nutrient fortificant and food additive, face challenges in stability and biosafety. These limitations hinder their application in the food industry. In this study, <i>Ganoderma lucidum</i> melanin (GLM) was utilized as a natural stabilizer. Three distinct types of GLM-stabilized SeNPs, termed GLM-SeNPs (S-GLM, D-GLM, and A-GLM), were subsequently synthesized via an ascorbic acid reduction method. The results showed that the prepared nanoparticles exhibited uniform particle size (55-75 nm) and good dispersibility. Among them, S-GLM possessed the highest selenium content (2598.90 mg/kg) and demonstrated the best stability. GLM-SeNPs significantly downregulated (<i>p</i> < 0.05) the mRNA expression of key pro-inflammatory cytokines (TNF-α, IL-6, and IL-1β) and upregulated (<i>p</i> < 0.05) the mRNA expression of the anti-inflammatory factor IL-10 in LPS-induced RAW264.7 macrophages. A potential mechanism underlying this effect may be the suppression of the NF-κB signaling pathway. In addition, GLM-SeNPs exhibited potent inhibitory effects against common foodborne pathogens. This study explores a potential novel strategy for the high-value utilization of natural functional components in food systems. These preliminary findings suggest GLM-SeNPs may have application potential in areas like functional beverages and food preservation. Further research is warranted to validate their feasibility in real food systems.