Anti-Inflammatory Effects of Sesamin-Loaded Nanoparticles in LPS-Stimulated RAW 264.7 Macrophages

Background/Objectives: Sesamin is a bioactive lignan with well-documented anti-inflammatory activity but limited therapeutic application due to poor aqueous solubility and low bioavailability. This study developed phosphatidylcholine-based sesamin-loaded nanoparticles (NSM) to enhance sesamin dispersibility, stability, and anti-inflammatory efficacy. Methods: NSM were prepared by solvent displacement. In vitro release was evaluated. Cytotoxicity testing in RAW 264.7 macrophages identified non-toxic concentration ranges for subsequent assays. Anti-inflammatory activity was assessed in lipopolysaccharide (LPS)-stimulated macrophages. Results: NSM exhibited a hydrodynamic diameter of 113.6 ± 3.6 nm with an acceptable PDI, remaining physically and chemically stable for 90 days at 4 °C. In vitro release revealed rapid and complete sesamin liberation from NSM within 2 h, whereas pure sesamin showed negligible release due to poor solubility. In LPS-stimulated macrophages, NSM significantly enhanced nitric oxide (NO) inhibition with an IC50 of 4.92 ± 0.40 µg/mL, markedly lower than sesamin (21.11 ± 3.42 µg/mL) and blank nanoparticles. NSM also strongly suppressed LPS-induced secretion of PGE2, TNF-α, IL-1β, and IL-6 in a dose-dependent manner, demonstrating superior inhibitory effects compared with pure sesamin. Conclusions: These findings indicate that phosphatidylcholine-based nanoparticles substantially enhance the anti-inflammatory potency of sesamin by increasing its solubility, cellular uptake, and biological activity. NSM represents a promising delivery platform for natural anti-inflammatory agents and warrants further investigation for therapeutic applications.