Construction and Bioavailability Analysis of 6-Shogaol-Loaded Zein Nanoparticles

In order to solve the problem of the low bioavailability of 6-shogaol (6S), in this study, zein-sodium caseinate nanoparticles (ZCP) were constructed by the anti-solvent precipitation method as a nano-delivery carrier for 6S. The physicochemical properties of 6S-loaded zein nanoparticles (ZCP-6S) were characterized and the bioavailability was investigated by in vitro simulated digestion, Caco-2 cell model and pharmacokinetic studies in rats. The particle size distribution, microstructure and chemical structure of ZCP-6S were characterized by laser particle size analyzer, transmission electron microscopy (TEM) and Fourier transform infrared (FTIR) spectroscopy. The results indicated that the nanoparticles were spherical in shape, with small particle size and uniform distribution. 6S might interact with zein through non-covalent bonds. The in vitro simulated digestion results showed that ZCP-6S increased the bioaccessibility of 6S to (75.34 ± 9.82)%. Moreover, ZCP-6S significantly enhanced the uptake and transport of 6S by Caco-2 cells. After 4 h treatment, the cell uptake increased by (0.36 ± 0.06) μg/mg. The concentration of 6S in the basolateral side of the Caco-2 cell model increased by (1.06 ± 0.06) μg/mL. In addition, pharmacokinetic studies showed that the relative oral bioavailability of 6S increased by 3.28 times after nanoparticle encapsulation. In summary, the bioaccessibility, cellular absorption and oral bioavailability of 6S were effectively improved by its encapsulation into zein nanoparticles.