HPLC characterization, molecular docking, QSAR and molecular dynamics simulation of Alstonia boonei phytochemical analogs as potent 5-alpha reductase inhibitors

Abstract

Current chemotherapy for Benign Prostatic Hyperplasia (BPH) relies on 5-alpha reductase inhibitors like Finasteride and Dutasteride, which are associated with significant side effects. This highlights the need for alternative treatments, particularly phytochemicals, which tend to have fewer adverse effects. Our study explores hit-to-lead optimization to enhance the potency and binding affinity of bioactive compounds from Alstonia boonei, aiming to develop more effective inhibitors of 5-alpha reductase. Nineteen phytochemicals were extracted and characterized from A. boonei stem bark. Molecular docking was performed to identify top-hit molecules optimized using a hit-to-lead approach to generate structurally improved analogs. QSAR-based screening was first used to filter out analogs predicted to be weak inhibitors of 5-alpha reductase, followed by structure-based screening to evaluate the remaining analogs based on docking scores and binding affinity. Molecular dynamics (MD) simulations were further used to predict the stability of ligand–protein interactions, with comparisons made to the reference ligand, Finasteride. The initial screening identified five hit molecules—Curcumin, Quercetin, Chrysarobin, Gallic acid, and Stigmasterol—with docking scores of − 8.766, − 8.737, − 8.234, − 7.760, and − 7.446 kcal/mol, respectively. Through hit-to-lead optimization, 5000 analogs were generated and filtered down to 4033 using the QSAR model, leading to the identification of top-performing analogs with significantly improved docking scores of − 9.980, − 9.974, − 9.930, − 9.827, and − 9.809 kcal/mol. These values surpass the co-crystallized ligand, Finasteride (− 7.229 kcal/mol), highlighting their enhanced binding affinity. Free energy calculations and MD simulations confirmed the stability of these ligand–protein complexes, showing favorable RMSD and binding free energy profiles compared to Finasteride. This study demonstrates the effectiveness of hit-to-lead optimization in generating potent 5-alpha reductase inhibitors with improved binding affinity and stability. The top analogs exhibit superior docking scores and MD stability compared to Finasteride, indicating strong potential as alternative BPH treatments. However, further in vitro and in vivo studies are necessary to confirm their efficacy and safety.