Unique dynamic mode between Artepillin C and human serum albumin implies the characteristics of Brazilian green propolis representative bioactive component

As a representative bioactive component in Brazil green propolis, Artepillin C (ArtC; 3, 5-diprenyl-4-hydroxycinnamic acid) has been reported a wide variety of physiological activities including anti-tumor, anti-inflammatory, and antimicrobial activity etc. However, it seems incompatible that ArtC in vivo was characterized as low absorption efficiency and low bioavailability. In order to obtain the elucidation, we further investigated the physicochemical basis of ArtC interacting with human serum albumin (HSA) in vitro. We found a unique dynamic mode interaction between ArtC and HSA, which is completely different from other reported propolis bioactive components. Thermodynamic analysis showed that hydrophobic interactions and electrostatic forces are the main driving force. The competitive assay indicates that the binding site of ArtC with HSA is close to the Sudlow’s site I. The findings of this study reveal the unique physicochemical transport mechanism of ArtC in the human body, which helps to further understand the uniqueness of the representative functional components of Brazilian green propolis in the human body.