ABSTRACT: Background: Dillenia indica L. (Dilleniaceae), commonly known as Elephant Apple, is a prominent ethno medicinal species utilized across Southeast Asia for managing metabolic syndromes, particularly Diabetes Mellitus, and inflammatory disorders. Despite its traditional acclaim, rigorous standardization and molecular validation of its bioactive constituents remain critical for its integration into modern phyto-pharmacotherapy. Objective: This review provides a comprehensive analysis of the isolation, structural characterization, and quantitative estimation of Gallic acid and Quercetin from D. indica, alongside a critical evaluation of their ant diabetic mechanisms. Methods: A systematic survey of literature up to 2026 was conducted across major scientific databases including Scopus, Pub-Med, and Web of Science. The review synthesizes modern extraction protocols, including Ultrasound-Assisted Extraction (UAE), and analytical strategies involving RP-HPLC, HPTLC, LC-MS/MS, and NMR spectroscopy. Results: Phyto-chemical profiling identifies Gallic acid and Quercetin as the primary bioactive markers responsible for the plant’s therapeutic profile. Pharmacological data demonstrate that these compounds exert potent anti-diabetic effects through the competitive inhibition of alpha-amylase and alpha-glucosidase values comparable to Acarbose), enhancement of GLUT4 translocation via the PI3K/Akt and AMPK pathways, and protection of pancreatic beta-cells from oxidative apoptosis. Furthermore, the review outlines validated HPLC/HPTLC methods that ensure batch-to-batch consistency and therapeutic reliability for D. indica-based formulations. Conclusion: The integration of Gallic acid and Quercetin as analytical markers provides a robust scientific framework for the quality control of D. indica. Future research should prioritize pharmacokinetic profiling and clinical trials to bridge the gap between traditional use and evidence-based clinical application in diabetes management.