Abstract

Despite the widespread medicinal use of Dillenia indica L. across Asia, a comprehensive comparative analysis of its various morphological parts, specifically the root, has remained largely unexplored. This research introduces a novel comparative methodology to define the distinct chemical and biological signatures of four plant parts (leaf, stem, unripe fruit, and root). Notably, extracts from the root and stem exhibited approximately 2x higher DPPH scavenging activity and nearly 25x greater α-glucosidase inhibition compared to those from the leaf and fruit. The root extract specifically demonstrated a 5x higher H₂O₂ scavenging capacity than all other extracts, which strongly correlates with its elevated glyceride, phenolic, and xanthone content. Conversely, the leaf extract displayed selective α-amylase inhibition, an activity potentially attributed to its specific alcohol and terpenoid contents. Furthermore, all extracts demonstrated selective cytotoxicity against colorectal cancer cells over normal fibroblasts, with leaf extract showing the greatest potency (IC₅₀ = 297.83 µg/mL at 72 h). These findings highlight the part-specific bioactivities of D. indica, supporting the rational selection of plant parts for developing safe, targeted functional foods and herbal products for preventive healthcare and chronic disease management.

Key words: Dillenia indica, Phytochemical profiling, Enzyme inhibition, Pearson correlation, Selective cytotoxicity