The present study investigates the activity of the natural compound piperine on prostate cancer cell line (PC-3), followed by exploring its mechanistic inhibition on the RAC-alpha serine/threonine-protein kinase (AKT1) protein. The 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) assay showed that after 24 hrs of exposure to piperine (15 µmol/ml), cell viability fell to 50% compared to the standard drug flutamide (SDF) (51 µmol/ml) with a lower IC50 concentration. However, the Dual acridine orange/ethidium bromide (AO/EtBr) staining demonstrated that, as compared to the SDF, piperine caused substantial cellular death in PC-3 cells, presumably by triggering DNA fragmentation. In addition, compared to untreated cells, the proportion of the sub-G0/G1 and G2/M stages population increased considerably in piperine-treated cells. The cell cycle's sub-G0/G1 and G2/M phases were also arrested in piperine-treated cells compared to the SDF in cell cycle analysis. Based on our systems pharmacology and molecular docking studies, AKT1 is predicted as a potential target against piperine. The complementary charge between AKT1 and piperine was emphasized in the transient ligand-protein binding interaction in molecular dynamic modeling over 100 ns, and stable hydrogen bond interaction between Lys268 and Ser205 amino acid residues of the active pocket was hypothesized. Overall, the findings from our in vitro and MD simulations provide insights into the mechanism of piperine targeting AKT1 and offer a possible candidate for future prostate cancer therapeutic development.Communicated by Ramaswamy H. Sarma.
Keywords: AKT1; MD simulations; SDF; docking; piperine; prostate cancer.