Casein nanoparticles as oral delivery carriers for improved bioavailability and hypoglycemic activity of apigenin.

Apigenin (AP) has been reported with several pharmacological effects such as, antioxidant, anti-inflammatory, anticancer and antidiabetic. Due to low solubility and bioavailability, apigenin has not been widely used in clinical practice. Casein has been widely used as the delivery material for various compounds. In this study, apigenin-casein nanoparticles (AP-Cas-NPs) were fabricated for improving the water solubility and bioavailability of apigenin. The particle size, PDI, zeta potential, encapsulation efficiency and loading content of AP-Cas-NPs were 238.7 ± 2.1 nm, 0.182 ± 0.015, −7.48 ± 0.24 mV, 48.56% and 23.37%, respectively. The characterization results of FTIR, XRD, DSC and 1HNMR revealed that AP was encapsulated in casein through hydrogen bond and existed in amorphous form in the nanoparticles. In vitro dissolution study confirmed that AP-Cas-NPs increased the solubility and dissolution rate of AP. The oral bioavailability of AP-Cas-NPs was increased by 3 times compared with the raw AP. In addition, AP-Cas-NPs also increased the gastrointestinal stability and the hypoglycemic activity of AP. Consequently, These findings suggested that AP-Cas-NPs is a promising and viable strategy for improving the bioavailability of apigenin or other or other bioactive components.