AMBIVALENT ROLE OF GALLATED CATECHINS IN GLUCOSE TOLERANCE IN HUMANS: A NOVEL INSIGHT INTO NON-ABSORBABLE GALLATED CATECHIN-DERIVED INHIBITORS OF GLUCOSE ABSORPTION

作者：Park J H; Jin J Y; Baek W K; Park S H; Sung H Y; Kim Y K; Lee J; Song D K^*

来源：Journal of Physiology and Pharmacology, 2009, 60(4): 101-109.

• gallated catechin
• type 2 diabetes
• obesity
• glucose absorption
• insulin resistance
• glucose uptake

Prolonged postprandial hyperglycemia is a detrimental factor for type 2 diabetes and obesity. The benefit of green tea extract (GTE) consumption still requires confirmation. We report the effects of circulating green tea catechins oil blood glucose and insulin levels. Oral glucose loading 1h after GTE ingestion in humans led to higher blood glucose and insulin levels than in control subjects. Gallated catechins were required for these effects, although within the intestinal lumen they have been known to decrease glucose and cholesterol absorption. Treatment with epigallocatechin-3-gallate hindered 2-deoxyglucose uptake into liver, fat, pancreatic beta-cell, and skeletal Muscle cell lines. The glucose intolerance was ameliorated by gallated catechin-deficient GTE or GTE mixed with polyethylene glycol, which was used as all inhibitor of intestinal absorption or gallated catechins. These findings may suggest that the gallated catechin when it is in the circulation elevates blood glucose level by blocking normal glucose uptake into the tissues, resulting in secondary hyperinsulinemia, whereas it decreases glucose entry into the circulation when they are inside the intestinal lumen. These findings encourage the development of non-absorbable derivatives of gallated catechins for preventative treatment of type 2 diabetes and obesity, which would specifically induce only the positive luminal effect.

• 出版日期2009-12