Epigallocatechin-3-gallate (EGCG), a prominent plant-based catechin predominantly derived from Camellia sinensis and widely available on the market as a health supplement, has garnered significant attention for its potential therapeutic benefits, particularly in the context of type 2 diabetes mellitus (T2DM). This review explores the multifaceted role of EGCG in addressing the “ominous octet”—the 8 core pathophysiological defects associated with T2DM. The literature search was carried out using key terms “EGCG” OR “epigallocatechin-3-gallate” OR “epigallocatechin gallate” AND “diabetes” OR “insulin resistance” OR “hyperglycemia” in the PubMed and Scopus databases. The search was constrained to articles published between January 2018 and April 2024, focusing on the document type. Full-text articles published in English and relevant to EGCG that featured a single active ingredient, included clearly explained diabetes relief mechanism, and included ominous octet aspects were included in the final review. The outcomes of the included studies were reviewed and categorized based on 8 core pathophysiological defects, collectively referred to as the ominous octet in T2DM. This review concludes that EGCG is a potent hypoglycemic agent that has beneficial effects against the ominous octet in addition to its pharmacological activities in modulating gut microbiota dysbiosis, carbohydrate digestion and metabolism, glucose transporter-mediated intestinal glucose-uptake, endothelial dysfunction, and renal damage that are significantly associated with pathogenesis of T2DM. This extensive scientific evidence suggests that EGCG may offer a novel approach to traditional antidiabetic therapies, potentially improving glycemic control and mitigating complications associated with T2DM. The inhibitory effects of EGCG on sodium-glucose transport proteins and their role in reducing renal glucose reabsorption remain unexplored, highlighting a significant research gap. Future research should also aim to broaden the scope by investigating the “egregious eleven”, which comprise a more comprehensive range of diabetic pathophysiological features. This review underscores the therapeutic promise of EGCG for managing T2DM and encourages ongoing research to fully elucidate its clinical applications.

Key words: Epigallocatechin-3-gallate, Catechin, Diabetes mellitus, Hyperglycemia, Insulin resistance, Ominous octet