Molecular Docking Studies Reveal Rhein from rhubarb (Rheum rhabarbarum) as a Putative Inhibitor of ATP-binding Cassette Super-family G member 2

Background: ATP-binding cassette Super-family G member 2 protein is an active ATPbinding cassette transporter with the potential to combat cancer stem cells. Objective: Due to the lack of potential ATP-binding cassette Super-family G member 2 inhibitors, we screened natural inhibitors, which could be a safe source to control multidrug resistance by blocking the regulation of ATP-binding cassette Super-family G member 2 protein. Methods: Three-dimensional structure of ATP-binding cassette Super-family G member 2 protein downloaded from the protein databank and chemical structures of 166 selected compounds of the training dataset were retrieved from PubChem. Drug-likeness and docking analysis was conducted to shortlist the dataset for pharmacophore generation. LigandScout 4.1.5 used for pharmacophorebased screening of Zbc library of ZINC database and Autodock Vina were utilized for molecular docking against the predicted active pocket of the target protein to evaluate the potential association of protein and ligands. The physiochemical properties of novel compounds were calculated by admetSAR respectively. Results: Through pharmacophore-based screening, ZINC4098704 (Rhein) was identified as a lead compound which demonstrates the least binding energy (-8.5) and the highest binding affinity with the target protein and showed optimal physiochemical profile. This compound is highly recommended for a laboratory test to confirm its activity as an ATP-binding cassette Super-family G member 2 inhibitors. Conclusion: Our computer-based study systematically selected natural lead compounds, which could be effective in inhibiting ATP-binding cassette Super-family G member 2 and may help reverse the effect of multidrug resistance to increase the effectiveness of chemotherapy in cancer treatment.