Molecular interactions of icariin and icariside II with human serum albumin: a spectroscopic and molecular docking analysis

Icariin and icariside II are flavonoids derived from Epimedium Herba, which exhibit significant pharmacological potential across various diseases. However, limited research exists regarding their interaction with human serum albumin (HSA). Therefore, this study was conducted to investigate the binding characteristics of icariin and icariside II with HSA through ultraviolet-visible, fluorescence, and synchronous fluorescence spectroscopy, as well as molecular docking analysis. Our results revealed that HSA possessed one binding site for icariin and icariside II, with the fluorescence of the protein exhibiting static quenching in the presence of these flavonoids. The binding mechanism for icariin was predominantly electrostatic, whereas that for icariside II was primarily hydrophobic. Furthermore, molecular docking demonstrated binding energies of −7.006 kcal/mol for icariin and −8.573 kcal/mol for icariside II. Overall, this study provides insights into the interaction between these two bioactive drugs and HSA, potentially contributing to the development of effective clinical dosing regimens.