In both Type 1 diabetes (T1D) and Type 2 diabetes (T2D), inadequate beta-cell mass and beta-cell dysfunction lead to impaired insulin secretion, and ultimately worsen glycemic control. Green tea has drawn wide attention due to its possible health-promoting properties, including enhancement of beta-cell function. We assessed the acute and relative long-term effects of epigallocatechin gallate (EGCG) on insulin secretion and synthesis from clonal beta-cells (INS1E cells), rat islets, and human islets, using 0.1, 1, or 5 µM. We determined if EGCG decreased blood glucose in healthy rats acutely, using 50 or 150 mg/kg body weight (BW), and after 12 days of supplementation in drinking water, using 0.1% and 0.5%. In the in vitro studies, EGCG significantly potentiated glucose-stimulated insulin secretion (GSIS) in rat islets (at 0.1, 1, and 5 µM) and human islets (at 1 µM), and elevated insulin content within INS1E cells (at 0.1, 1, and 5 µm) and human islets (at 1 µM), (P<0.05). Nutritional supplementation of EGCG (0.5% in drinking water) for 12 days in healthy rats significantly increased insulin synthesis, compared to that of controls, from 0.2 ± 0.02 to 1.4 ± 0.2 ng/mg protein, without alteration of insulin secretion in isolated islets (P<0.05). These findings demonstrate that EGCG may play a role in the regulation of pancreatic beta-cell function, thereby contributing to an anti-diabetic effect of this agent. / Master of Science
Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/32761 |
Date | 06 June 2008 |
Creators | Yuskavage, Julia Kathryn |
Contributors | Human Nutrition, Foods, and Exercise, Liu, Dongmin, Gwazdauskas, Francis C., Barbeau, William E. |
Publisher | Virginia Tech |
Source Sets | Virginia Tech Theses and Dissertation |
Detected Language | English |
Type | Thesis |
Format | application/pdf |
Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
Relation | JuliaYuskavageRevisedETD.pdf |
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