Target-based Antidiabetic Indole Derivatives and Insights into Structure-activity Relationships: A Mechanistic Update 2020-2025

INTRODUCTION: Type 2 diabetes mellitus (T2DM) continues to rise globally, and the limitations of existing therapies highlight the urgent need for novel interventions. Indole derivatives have emerged as promising candidates due to their structural adaptability, multi-target engagement, and favorable pharmacokinetic profiles. METHODS: We conducted a comprehensive review of literature published between 2020 and 2025, systematically searching PubMed, Scopus, and Web of Science for studies on indole-based antidiabetic agents. The inclusion criteria emphasized mechanistic insights, structure-activity relationships (SAR), preclinical advancements, and early clinical evaluations. RESULTS: Over 120 indole derivatives were identified targeting key diabetes-related pathways, including AMPK activation, insulin receptor sensitization, β-cell protection, and enzyme inhibition (e.g., DPP-4, α-glucosidase). SAR analyses revealed that position-specific modifications at N1, C2, C3, and C5 significantly enhance bioactivity and selectivity. Innovations in synthesis (e.g., microwave-assisted, green chemistry approaches), formulation (e.g., nanoparticles, prodrugs), and AI-assisted drug design have improved clinical viability. DISCUSSION: The evidence supports the unique polypharmacological profile of indole scaffolds, enabling multi-pathway modulation and addressing both hyperglycaemia and its complications. Challenges remain regarding toxicity, solubility, and translational gaps, but emerging delivery strategies and personalized medicine approaches show promise. CONCLUSION: Indole derivatives represent a transformative class of antidiabetic agents with multitarget activity and strong therapeutic potential, warranting further clinical validation to optimize their role in precision medicine.