Phytochemical and bioactivity insights into <i>Pouzolzia zeylanica</i> tuber: triterpenoid/sterol dominance with antioxidant and protein-stabilising effects

The ethanolic extract of coastal root tubers of <i>Pouzolzia zeylanica</i> was systematically characterised for its phytochemical composition and bioactivities. Analyses revealed positive results for phenolics and flavonoids and strong saponin reactions, with total contents of 74.39 ± 0.68 mg GAE/g (phenolics), 28.96 ± 1.10 mg QE/g (flavonoids), and 176.25 ± 7.50 mg OA-eq/g (saponins). UPLC-QTOF-MS profiling identified 158 metabolites, dominated by triterpenoid and sterol scaffolds. The extract exhibited antioxidant activity (IC₅₀ values: DPPH 1.622 ± 0.074 mg/mL, ABTS 0.609 ± 0.110 mg/mL, FRP 0.320 ± 0.008 mg/mL) and strong anti-inflammatory potential in the BSA denaturation assay (IC₅₀ 0.024 ± 0.008 mg/mL). Enzyme inhibition was modest (IC₅₀ values: <i>α</i>-amylase 301.34 ± 12.61 mg/mL; <i>α</i>-glucosidase 107.15 ± 5.43 mg/mL), consistent with the absence of enrichment for specific glycosidase inhibitors. These findings highlight <i>P. zeylanica</i> tubers as a triterpenoid- and saponin-rich matrix capable of conferring antioxidant and anti-inflammatory protection.