Co-assembling nanoparticles of Asiatic acid and Caffeic acid phenethyl ester: Characterization, stability and bioactivity in vitro.

Caffeic acid phenethyl ester (CAPE) is an efficient bioactive polyphenol ester derived from propolis. However, its poor water solubility, bioavailability, and stability significantly limit its application. Based on the assembly properties of some natural small molecules (NSMs), asiatic acid-caffeic acid phenethyl ester nanoparticles (ASA-CAPE NPs) were prepared to overcome the above defects. After proportion optimization, the encapsulation and loading efficiencies of ASA-CAPE NPs reached 47.72 ± 0.17 % and 11.62 ± 0.42 %, respectively. Characterization results showed that ASA-CAPE NPs, mainly assembled by hydrogen bonds and hydrophobic forces, possessed regular spherical morphology with a diameter size of less than 300 nm. Additionally, ASA-CAPE NPs presented improved water solubility, stability, and bioactivities than free CAPE. Besides, ASA-CAPE NPs also exhibited good sustained release of CAPE during the gastrointestinal digestion in vitro. Above all, ASA-CAPE NPs provide a new idea for efficiently utilizing hydrophobic active compounds in the functional food field.