Controlled release of caffeine from oat globulin nanocomplexes: Biocompatibility and gastrointestinal dynamics

Caffeine, a widely consumed stimulant, is known for its rapid absorption and clearance, leading to fluctuations in plasma concentration and potential gastrointestinal irritation. This study explored the interaction between oat globulin (OG) and caffeine, focusing on OG's ability to stabilize caffeine's release and bioavailability. Fluorescence quenching, FTIR and molecular docking indicated that each OG molecule is capable of binding 8.32 ± 1.59 molecules of caffeine with a high affinity. In vitro digestion simulations demonstrated slower caffeine release from the OG-caffeine nanocomplex, reducing toxicity to gastric epithelial cells (GES-1). In vivo studies showed that the OG-caffeine nanocomplex lowered the peak plasma concentration (C_max = 1.761 ± 0.367 microg/mL) and extended the half-life of caffeine (T_1/2 = 62.159 ± 7.156 min), enhancing its sustained effect. Additionally, cytotoxicity assays revealed that the OG-caffeine nanocomplex exhibited improved biocompatibility, reducing the irritant effects of caffeine on GES-1 cells. This study highlights the novel application of plant-based OG as an effective carrier to improve the delivery and safety of caffeine without synthetic additives.