Enhanced-release of phenolic-enriched grape seed antioxidants through innovative cholesterol doped phytosomes

Grape seed (GS) is a predominant food by-product in the wine industry and a valuable source of antioxidants due to its high content of polyphenols and fiber. This study aimed to develop an antioxidant-rich GS fraction and formulate appropriate delivery systems for oral administration. A hydroethanolic extract of GS was enriched in phenolic compounds using adsorbent resin column chromatography, resulting in a 4-fold increase in phenolic content compared to the crude extract. The phenolic-enriched fraction was loaded into cholesterol-incorporated phytosomes to improve stability, gut absorption, and oral bioavailability. Different polysaccharide-based polymers were tested as natural-based coatings to improve stability and protection against gastrointestinal degradation while providing a modified-release profile. The phytosomes were evaluated for product yield, particle size, surface charge, surface morphology, and release profile under simulated gastrointestinal conditions. Cholesterol-incorporated phytosomes exhibited an anionic surface charge and a mean hydrodynamic particle size of 168 nm. Both molecular docking and FTIR analyses confirmed the interaction between the lipid bilayer and phenolic compounds. Mathematical fitting models confirmed the modified release profile of the polysaccharide-coated phytosomes. Our enriched phytosomes have potential as smart nutraceuticals for dietary supplements.