A Pyrone Glucoside from Maerua angolensis Induces Caspase-Dependent Apoptosis and Targets AKT1, PARP-1, and Caspase-7 in Triple-Negative Breast Cancer.

Triple-negative breast cancer (TNBC) is an aggressive subtype lacking effective targeted therapies, highlighting the need for new anticancer agents. Natural products remain a valuable source of bioactive compounds with diverse mechanisms of action. In this study, a pyrone glucoside, 7-hydroxymaltol-3-O-β-D-glucoside, was isolated from the methanolic leaf extract of Maerua angolensis and evaluated for its anticancer activity against TNBC cells. Structural elucidation was achieved using NMR and LC-MS analyses. Both the crude extract and the isolated compound exhibited dose-dependent cytotoxicity against MDA-MB-468 cells, with IC50 values of 2.94 and 0.78 µg/mL, respectively, while showing reduced toxicity toward MCF10A normal cells. Mechanistic studies revealed induction of apoptosis, evidenced by activation of caspase-9 and caspase-7 and PARP cleavage. Confocal imaging further demonstrated lysosomal disruption and nuclear morphological alterations consistent with stress-associated cell death. Gene expression analysis indicated minimal involvement of the PI3K/AKT/mTOR pathway. Molecular docking showed favorable binding of the compound to AKT1, PARP-1, and caspase-7, suggesting a multi-target mode of action. ADMET analysis indicated low oral bioavailability but a favorable safety profile. These findings highlight the potential of this compound as a lead for TNBC therapy.