Interaction of triterpenoids with human serum albumin: A review

Triterpenoids are a large group of natural and synthetic products. This review deals with the current state of knowledge on their interaction with serum albumin. The binding of drugs to albumin may control their distribution in tissues. In literature, different techniques were used to investigate the albumin-triterpenoid interaction and include fluorescence spectroscopy, Fourier transform infrared spectroscopy, circular dichroism, calorimetric techniques and molecular modeling. Changes in fluorescence intensity of albumin were observed upon triterpenoid-albumin complex formation. Thermodynamic analyses proved that hydrophobic interactions and hydrogen bonds were the mainly binding forces in triterpenoid-albumin systems. Molecular docking and site marker competitive experimental results revealed that triterpenoids bound to Sudlow's site I of albumin. Furthermore, Fourier transform infrared spectroscopy and circular dichroism spectra analysis indicated that the native conformation of the protein is affected upon binding to triterpenoids.