Preparation and characterization of zein-lecithin-total flavonoids from Smilax glabra complex nanoparticles and the study of their antioxidant activity on HepG2 cells

Total flavonoids from Smilax glabra (TFSG) exhibit several biological activities; however, their poor stability limits their application. In this work, zein-lecithin-TFSG complex nanoparticles (Z-L-TFSG NPs) were prepared using the anti-solvent coprecipitation technique. The prepared Z-L-TFSG NPs were spherical with an encapsulation efficiency of 98.0%. Differential scanning calorimetry, Fourier transform infrared spectroscopy, and morphology tests revealed that the TFSG were successfully encapsulated by Z-L NPs. Z-L-TFSG NPs showed superior stability and better controlled release characteristics in simulated gastrointestinal digestion. The encapsulation of TFSG by Z-L NPs could improve their antioxidant capacity in vitro. Moreover, Z-L-TFSG NPs could enhance the protective effects of TFSG against H2O2-induced oxidative damage to HepG2 cells. The results indicated that the Z-L self-assembled NPs could serve as a promising drug delivery system through the integrated encapsulation of multiple flavonoids.