A review: Using nanoparticles to enhance absorption and bioavailability of phenolic phytochemicals

Phenolic phytochemicals have been of particular interests in food and pharmaceutical fields because they have potential to reduce the incidences of coronary heart disease, diabetes, cancers, and other chronic diseases. However, extremely low absorption rate of phenolic phytochemicals restricts their bioactivity in vivo. Such low absorption and bioavailability are due to their low water solubility, poor stability, passive diffusion, and active efflux in the gastrointestinal tract. Nanoparticle delivery system has been widely applied in pharmaceutical field to enhance absorption of bioactive compounds. This review explains absorption barriers of phenolic phytochemicals in the gastrointestinal tract. Nanoparticles delivery systems are emphasized regarding fabrication methods and their potential benefits on phenolic phytochemical absorption. Particularly, absorption mechanisms of nanoparticles by epithelial cells and biodistribution of nanoparticles after absorption are mainly discussed. Moreover, the potential challenges of nanoparticles as delivery system for phenolic phytochemicals in the gastrointestinal tract are also discussed.