Affiliations: Department of Food and Nutrition, Seoul National
University, Seoul 151-742, South Korea
Note: [] Address for correspondence (present address): Md. S. Islam,
Department of Nutrition, Faculty of Health Sciences, North-West University
(Potchefstroom Campus), Potchefstroom 2520, South Africa. Tel.: +27 18 299
2466; Fax: +27 18 299 2464; E-mail: sislam1974@yahoo.com
Abstract: Present study was conducted to clarify whether lower or higher
dietary dose of green tea is beneficial for the reduction of risk of type 2
diabetes. Five weeks old male SD rats were fed high fat diet for 2 weeks then
divided into 4 groups of 8 animals as Normal Control (NC), Diabetic Control
(DBC), Green Tea Low (GTL, 0.5%, Green Tea High (GTH, 2.0%) groups.
Diabetes was induced by intra-peritoneal (i.p) injection of STZ (40 mg/kg BW)
in all animals except NC group. After 4 weeks feeding of experimental diets,
serum fasting blood glucose was not decreased but relatively increased in both
green tea fed groups compared to DBC group. Serum insulin concentration was
significantly (p< 0.05) increased in GTL group but not in
GTH group when compared with DBC group. Serum lipids were significantly
decreased in GTH group but not in GTL group compared to DBC group.
Intra-peritoneal glucose tolerance test, blood HbA1c, liver weight, and liver
glycogen level were not influenced by the feeding of green tea containing
diets. Data of this study suggest that lower dose of green tea is
insulinotropic when higher dose is hyperglycemic but hypolipidemic at least in
this experimental condition.
Keywords: Type 2 diabetes, green tea, high fat, rats
Journal: BioFactors, vol. 29, no. 1, pp. 45-53, 2007
