Epigallocatechin-3-gallate (EGCG), a bioactive polyphenol abundant in green tea, has garnered significant attention for its diverse therapeutic applications, ranging from antioxidant and anti-inflammatory effects to potential anticancer properties. Despite its immense promise, the practical utilization of EGCG in therapeutic settings as a medication has been hampered by inherent limitations of this drug, including poor bioavailability, instability, and rapid degradation. This review comprehensively explores the current challenges associated with the application of EGCG and evaluates the potential of nanoparticle-based formulations in addressing these limitations. Nanoparticles, with their unique physicochemical properties, offer a platform for the enhanced stability, bioavailability, and targeted delivery of EGCG. Various nanoparticle strategies, including polymeric nanoparticle, micelle, lipid-based nanocarrier, metal nanoparticle, and silica nanoparticle, are currently employed to enhance EGCG stability and pharmacological activity. This review concludes that the particle sizes of most of these formulated nanocarriers fall within 300 nm and their encapsulation efficiency ranges from 51% to 97%. Notably, the pharmacological activities of EGCG-loaded nanoparticles, such as antioxidative, anti-inflammatory, anticancer, and antimicrobial effects, are significantly enhanced compared to those of free EGCG. By critically analyzing the existing literature and highlighting recent advancements, this article provides valuable insights into the promising prospects of nanoparticle-mediated EGCG formulations, paving the way for the development of more effective and clinically viable therapeutic strategies.
Animals ; Humans ; Anti-Inflammatory Agents/administration & dosage* ; Antineoplastic Agents/administration & dosage* ; Antioxidants/administration & dosage* ; Biological Availability ; Catechin/analogs & derivatives* ; Micelles ; Particle Size ; Nanoparticle Drug Delivery System/chemistry*

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. Please cite this article as: Wong CN, Lim YM, Liew KB, Chew YL, Chua AL, Lee SK. A review on mechanistic actions of epigallocatechin-3-gallate in targeting the ominous octet of type 2 diabetes mellitus. J Integr Med. 2025; 23(4): 344-356.
Diabetes Mellitus, Type 2/physiopathology* ; Humans ; Catechin/therapeutic use* ; Hypoglycemic Agents/therapeutic use* ; Animals ; Insulin Resistance