Interaction of Curcumin with One Subunit of Monoamine Oxidase-B in Comparison with Safinamide: An In Silico Study

Curcumin is a plant derivative with biological effects, including potential for the treatment of Parkinson’s disease (PD). It is known that monoamine oxidase B (MAO-B) is involved in PD due to its role in the degradation of various neurotransmitters like dopamine, the main declined factor in PD. Since MAO-B inhibitors (e.g. safinamide) are used as the support for the treatment of PD, we planned to evaluate the in silico interaction of curcumin with one subunit of the MAO-B enzyme in comparison with safinamide. The crystal structure of human MAO-B (PDB entry code 3PO7) was selected from the Protein Data Bank (https://www.rcsb.org). The molecular structures of curcumin (CID: 969516) and safinamide (CID: 131682) were obtained from PubChem (https://pubchem.ncbi.nlm.nih.gov). Chimera 1.8, AutoDock Tools-1.5.6 software and AutoDock4 software were used for this in silico study. The results revealed that the binding energies (ΔG)s of the conformations of curcumin and safinamide, showing the best down ΔG, were -11.15 kcal/mol and -11.09 kcal/mol, respectively. Moreover, the inhibition constants (Ki)s of both ligands were near quantities. Hence, it may suggest that curcumin and safinamide form nearly similar stability with the subunit of the MAO-B enzyme. More experimental studies may reveal the similarity of curcumin with safinamide about the inhibitory effect on MAO-B.