Golnaz ParviziFard - Drug Analysis Research center, Tabriz University of medical sciences, Tabriz, Iran.
Mostafa Zakariazadeh - Drug Analysis Research center, Tabriz University of medical sciences, Tabriz, Iran.
Hossein Haghaei - Nutrition and food sciences faculty, Tabriz University of medical sciences, Tabriz, Iran.
Somaieh Soltani - Drug applied Research center and pharmacy faculty, Tabriz University of medical sciences, Tabriz, Iran.

In the present study the mechanism of interaction between diclofenac sodium and naproxen with human serum albumin (HSA) were investigated and compared. For this purpose, spectroflurimetery technique and molecular docking have been applied. By attention to the obtained results, some valuable parameters were investigated such as the values of binding sites (n), quenching constant (Ksv), binding constants (Kb) and thermodynamic parameters. Also, the molecular mechanism of interactionwere studied by using molecular modeling method. Obtained results suggest that the interaction between both drugs and HSA are strong where diclofenac interaction is power than naproxen. Both drugs almost occupied one binding site of HSA in room temperature while increasing of temperature effect adversely in binding capacity and thermodynamics parameters of drugs. Diclofenac obey the van der Waals and hydrogen bonding in the interaction with HSA whereas the hydrophobic reactions effect in the naproxen and HSA interactions. Docking results indicated the high binding free energy between drugs and HSA and site IB of HSA is favorable site for drugs binding in the lowest energy conformers. Hydrogen bonding are more favorable interaction in diclofenac-HSA system rather than naproxen-HSA system in molecular docking modeling.

Diclofenac sodium, Naproxen, Human Serum Albumin, fluorescence, Molecular docking