Stability and Bioactivity of <i>Abelmoschus sagittifolius</i> Extracts Following In Vitro Digestion

This study investigated the effects of in vitro digestion, for the first time, on the biological activities of Abelmoschus sagittifolius, an essential step in evaluating its potential as a functional food. Different extracts from tuber, root, flower, leaf, and fruit were examined for antioxidant, antidiabetic, and cytotoxic properties, along with their phytochemical compositions. Among those extracts, leaf exhibited the highest antioxidant activity (IC₅₀ = 0.13 mg/mL) and α-glucosidase inhibition (IC₅₀ = 0.18 mg/mL), while fruit demonstrated the greatest α-amylase inhibition (IC₅₀ = 0.8 mg/mL) and cytotoxicity against K562, U937, and THP1 cell lines (IC₅₀ = 0.22, 0.11, and 0.11 mg/mL, respectively). However, these activities significantly decreased through in vitro digestion. Notably, after digestion, the tuber showed a remarkable increase in cytotoxicity (inhibition up to 98.12%) and retained its α-amylase inhibitory effect. Phytochemical analysis suggested the preserved bioactivity of the tuber may result from a synergistic interaction among its constituents of phenolics, flavonoids, saponins, tannins, alkaloids, and polyamines. These findings highlight tuber as a promising candidate for functional foods targeting myeloid leukemia and metabolic disorders, although further investigations are required.