Mechanistic Studies on the Antidiabetic Properties of Gallotannins

The escalating prevalence of type 2 diabetes (T2DM) has emerged as a global public health dilemma. This ailment is associated with insulin resistance and heightened blood glucose concentrations. Despite the rapid advancements in modern medicine, where a regimen of medications is employed to manage blood glucose effectively, certain treatments manifest significant adverse reactions. Recent studies have elucidated the pivotal role of gallotannins in mitigating inflammation and obesity, potentially reducing the prevalence of obesity-linked T2DM. Gallotannins, defined by their glycosidic cores and galloyl groups, are ubiquitously present in plants, playing diverse biological functions and constituting a significant segment of water-soluble polyphenolic compounds within the heterogeneous tannins group. The structural attributes of gallotannins are instrumental in dictating their myriad biological activities. Owing to their abundance of hydroxyl groups (-OH) and complex macromolecular structure, gallotannins exhibit an array of pro-physiological properties, including antioxidant, anti-inflammatory, antidiabetic, protein-precipitating, and antibacterial effects. Extensive research demonstrates that gallotannins specifically obstruct α-amylase and pancreatic lipase, enhance insulin sensitivity, modulate short-chain fatty acid production, alleviate oxidative stress, exhibit anti-inflammatory properties, and influence the gut microbiota, collectively contributing to their antidiabetic efficacy. This review aims to consolidate and scrutinize the extant literature on gallotannins to furnish essential insights for their potential application in diabetes management.