ABSTRACT
ObjectiveTo prepare oral nanoemulsions encapsulating essential oil from Alpinia zerumbet fructus（EOFAZ） and to investigate its pro-absorption effect in vitro and distribution in vivo. MethodThe proteoglycan conjugate polysaccharides of vinegar-processed Bupleuri Radix-bovine serum albumin（VBCP-BSA） was prepared by Maillard reaction of VBCP and BSA. Taking VBCP-BSA as emulsifier， vitamin B12（VB12） as absorption enhancer， and medium chain triglycerides mixed with EOFAZ as oil phase， the nanoemulsions loaded with EOFAZ was prepared by high energy emulsification method. The particle size， particle size distribution， surface Zeta potential， EOFAZ content and appearance and morphology of the nanoemulsions were characterized， and fluorescein tracer method was used to investigate the absorption effect of fluorescein-labeled EOFAZ nanoemulsions in vitro and their distribution in vivo. ResultVBCP-BSA was formed by Maillard reaction for 48 h with high grafting rate. Using VBCP-BSA as emulsifier， the homogeneous pink nanoemulsions was prepared and denoted as EOFAZ@VBCP-BSA/VB12. The particle size of the nanoemulsions was less than 100 nm and the particle size distribution was uniform. The surface of the nanoemulsions was a weak negative charge， and the shape was spherical. The encapsulation rate of the nanoemulsions for EOFAZ was greater than 80%， which had a good absorption effect in vitro and could enhance liver accumulation after oral administration. ConclusionThe designed proteoglycan nanoemulsions can effectively load EOFAZ， promote oral absorption and enhance liver distribution， which can provide experimental basis for the development of oral EOFAZ liver protection preparations.