Molecular Docking Studies of Glabrene and Human Epidermal Growth Factor Receptor Kinase

Background: Human epidermal growth factor receptor 2 (Her2) gene located in human chromosome17, encodes Her2 tyrosine kinase protein, and is overexpressed in breast cancer cells. Her2 is activated on phosphorylation of tyrosine by adenosine triphosphate (ATP). Nonetheless, Her2 excessively partakes in the development and prognosis of specific types of aggressive breast cancers. Therefore, Her2 inhibition therapy is primary target for the treatment of aggressive breast cancer. At present, lapatinib is one of the Food and Drug Administration approved Her2 inhibitors used in cancer therapy. In molecular docking process, glabrene with slightly higher binding energy competitively bound to the active receptor site comparable to lapatinib and ATP. Therefore, glabrene could emerge as a potential candidate for restricting Her2 overexpressed breast cancer. Objective: The present study aimed to demonstrate the inhibitory activity of glabrene, an isoflavene and xenoestrogen found in liquorice root, along with known Her2 inhibitor, lapatinib. Methods: ATP, lapatinib, and glabrene were docked on human Her2 protein 3D structure which revealed glabrene as a competitive Her2 inhibitor akin to lapatinib. Results: The docking results suggested the binding site similarities of ATP, lapatinib, and glabrene. The binding energies of docked ATP, lapatinib, and glabrene complexes with Her2 were −9.1 kcal/mol, −10.5 kcal/mol, and −11.3 kcal/mol, respectively. Conclusion: The in silico docking simulation of ATP, lapatinib, and glabrene suggested that glabrene is likewise a competitive Her2 inhibitor.