Polyvinylpyrrolidone-Encapsulated Total Flavonoids Nanoparticles for Enhancing Antioxidant and Anticancer Activities

Total flavonoids (TFs) extracted from Rosa davurica Pall. are known for their diverse biological activities, including antioxidant and anticancer properties. However, their application is significantly constrained by low solubility and poor bioavailability. In this study, the complex extract was transformed into total flavonoid nanoparticles (TFNPs) using the anti-solvent coprecipitation technique in the presence of polyvinylpyrrolidone (PVP). The resulting TFNPs possess a spherical shape, 61.9% encapsulation efficiency, and 46.3% loading capacity. Fourier transform infrared spectroscopy confirmed the hydrogen bonding interaction between the hydroxyl group (─OH) of total flavonoid components and the carbonyl group (C═O) of PVP. The TFNPs demonstrated significantly improved solubility under simulated gastrointestinal conditions compared to the raw TFs. Most importantly, in vitro studies showed that TFNPs exhibited not only higher anti-acute oxidative injury effects but also stronger anticancer ability than the raw TFs due to their higher solubility. These findings suggest that the encapsulation of TFs by polymeric nanoparticles could serve as a promising strategy to improve the solubility and bioavailability of these bioactive compounds.