Gallated Form of Tea Catechin, Not Nongallated Form, Increases Fecal Starch Excretion in Rats
| Autor: | Yoshimi Matsumoto, Tomonori Unno, Yukari Yamamoto |
|---|---|
| Rok vydání: | 2012 |
| Předmět: |
Male
Starch Medicine (miscellaneous) Epigallocatechin gallate complex mixtures Catechin Statistics Nonparametric Excretion Feces chemistry.chemical_compound Hydrolysis Dietary Carbohydrates Animals Gallic acid Food science Intestinal Mucosa Rats Wistar Nutrition and Dietetics Tea food and beverages Rats Bioavailability Intestines chemistry alpha-Amylases Digestion |
| Zdroj: | Journal of Nutritional Science and Vitaminology. 58:45-49 |
| ISSN: | 1881-7742 0301-4800 |
| Popis: | This study was carried out to elucidate the structural advantage of a gallated form of tea catechin on modulating bioavailability of dietary starch in rats. Animal studies demonstrated that the addition of 0.5% (w/w) (-)-epigallocatechin gallate (EGCG) to the diet brought about a significant increase in the starch content in the feces collected for 2 d at the fourth week of feeding over that with the control diet. Of the gross starch that the rats consumed from their respective diets during the fecal collection period, 0.1% (for control diet) and 1.9% (for EGCG diet) were estimated to be excreted in the feces. However, such a significant increase in the fecal excretion of starch by the EGCG diet was lost by undergoing hydrolysis of EGCG to (-)-epigallocatechin (EGC) and gallic acid (GA). In vitro investigation also showed that EGCG inhibited porcine pancreatic α-amylase activity in a concentration-dependent fashion, whereas the hydrolyzed preparation (the mixture of EGC and GA) exhibited a lack of the inhibitory activity for α-amylase. The modification of dietary starch digestion by inhibiting intestinal α-amylase activity with EGCG may be responsible at least in part for increasing fecal output of starch in rats. Thus, the attachment of a galloyl moiety to the tea flavan-3-ol skeleton may be of key importance for reducing intestinal digestion of dietary starch in rats. |
| Databáze: | OpenAIRE |
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