<p>In this study, bioassay-guided fractionation of the leaves of Vietnamese <i>Morus alba</i> L., Moraceae, led to the isolation of a series of prenylated flavonoids and benzofurans. These compounds were evaluated for their cytotoxic activities against several human cancer cell lines <i>in vitro</i>. Among them, moracin C exhibited the most potent cytotoxicity against human leukemia HL-60 cells with an IC₅₀ value of 6.7 ± 0.8&#xa0;µM. Mechanistic investigations revealed that moracin C induced apoptosis through activation of caspase-3, caspase-9, and poly (ADP-ribose) polymerase, key components of the intrinsic apoptotic pathway. Further in silico molecular docking studies demonstrated that moracin C showed a favorable binding affinity for caspase-3 (− 6.9&#xa0;kcal/mol), forming hydrogen bonds with Arg64 and Arg207, and hydrophobic interactions with Cys163 and Phe256, which are important residues for caspase-3 activation. Additionally, moracin C exhibited binding affinity for poly (ADP-ribose) polymerase (− 9.1&#xa0;kcal/mol), interacting via hydrogen bonds with Tyr907 and Gly894, and hydrophobic contact with Tyr896. To further confirm these results, molecular dynamics simulations over 100 ns were performed. The moracin C–caspase-3 complex displayed initial instability but reached equilibrium after 60 ns, indicating a dynamic yet stable interaction, while the moracin C– poly (ADP-ribose) polymerase complex showed high stability with minimal structural fluctuations. Our study provides strong evidence that moracin C, a key component isolated from <i>M.</i> <i>alba</i> leaves, exerts its cytotoxic effects by promoting apoptosis through both caspase activation and poly (ADP-ribose) polymerase inhibition. These findings may support the therapeutic potential of <i>M.</i> <i>alba</i> and moracin C in the development of novel treatments for human leukemia.</p> Graphical Abstract <p></p>