Abstract
The interactions between human serum albumin (HSA) and the hemostatic components of the Chinese medicine Sanguisorbae Radix (SR), specifically phenolic acid compounds such as caffeic acid (CA), ferulic acid (FA) and their 1:1 mixture (1:1) were studied to investigate the molecular mechanism underlying the hemostatic effect of SR. Network pharmacology combined with the experimental and computational data revealed that HSA is one of the hemostatic targets to SR phenolic acids. SDS-PAGE and multi-spectroscopy demonstrated that the phenolic acids bind to the Sudlow site I on HSA, altering its structure and influencing its migration velocity. There is an observed synergistic effect upon the mixture of CA and FA. Quantum chemistry, molecular docking, and molecular dynamics simulations indicate that the binding of phenolic acids to HSA is stable, and variations in binding efficiency are associated with the hydrophobicity of the substituent at the C3 position of the side chain, and also, the key amino acids and functional groups for hemostasis of SR were identified, along with the active sites that contribute to the synergistic enhancement by phenolic acids.