Organ-Specific Metabolite Profiling of <i>Mahonia aquifolium</i> (Pursh) Nutt. Extracts by GC-FID/MS and UHPLC-HRMS/MS with Bioactivity Assessment

<i>Mahonia aquifolium</i> (Pursh) Nutt., an ornamental shrub abundant in bioactive metabolites, was investigated using an organ-specific metabolite profiling approach. GC-FID/MS (after silylation) and UHPLC-HRMS/MS were employed to qualitatively and quantitatively characterize the constituents in extracts. The leaf extract exhibited the highest phenolic and flavonoid contents. 3-Hydroxytyrosol and flavanomarein were identified for the first time in specific plant organs. Antioxidant capacity and α-amylase inhibitory activity were evaluated using several <i>in vitro</i> assays. Cytotoxicity was evaluated on NIH/3T3 fibroblast cells and PMA-differentiated THP-1 macrophage-like cells. At the tested concentrations, none of the extracts exhibited relevant antiproliferative activity, with IC₅₀ values above 400 μg/mL for all samples; only the leaf extract showed a mild, time-dependent reduction in cell viability. These findings indicate limited cytotoxic activity at the applied doses. This study provides the first comprehensive polar metabolite and bioactivity map of four anatomical regions of <i>M. aquifolium</i>, highlighting organ-specific chemical diversity and potential applications in functional food and nutraceutical development.