Resveratrol-loaded nanoparticles based on the self-assembly behavior of Sparassis latifolia polysaccharides: Preparation, characterization, release behavior under in vitro digestion and synergistic hypoglycemic effects

Resveratrol (Res) is a naturally occurring polyphenolic compound exhibiting a wide range of biological activities. However, its application is limited due to the instability, poor water solubility, and low bioavailability. Therefore, this study aimed to prepare Sparassis latifolia polysaccharides (SLPs) nanoparticles loaded with Res (SLPs-Res NPs) through the self-assembly behavior of SLPs. Our findings revealed that SLPs underwent a conformational transition from triple helix to single strand when exposed to varying concentrations of dimethyl sulfoxide (DMSO). By virtue of this self-assembly characteristic, the spherical or subspherical nanoparticles loaded with Res were successfully fabricated. The optimal preparation conditions included an 80 % volume ratio of DMSO, a mass ratio of Res to SLPs at 1:32, and magnetic stirring for 2 h. Under these conditions, the average particle size of SLPs-Res NPs was 230.4 ± 7.8 nm, and the encapsulation efficiency of Res reached (66.69 ± 0.10)%. Hydrogen bonding and hydrophobic forces were involved in the formation of nanoparticles. SLP-Res NPs demonstrated enhanced photothermal stability and desirable sustained-release properties. It also exerted significant inhibitory effects on α-glucosidase activity in vitro and glucose-lowering effects in mice during glucose tolerance tests. This study presents an approach for delivering Res using self-assembled SLPs, demonstrating their potential as effective functional carriers for the encapsulation of hydrophobic bioactive molecules.