Effect of green tea extract on body weight, serum glucose and lipid profile in streptozotocin-induced diabetic rats. A dose response study.

OBJECTIVE To examine the effect of green tea extract on body weight, serum levels of glucose, and lipids in streptozotocin-induced diabetic rats. METHODS This experimental study was carried out in the Diabetes Research Center, Ahvaz University of Medical Sciences, Ahvaz, Iran from January 2011 to March 2011. Forty-eight male wistar rats (200-250 g) were divided randomly into 6 groups. Diabetes was induced by a single intraperitoneal injection of stereptozotocin (55 mg/kg). The experimental groups received alcohol extract of green tea leaves (100 mg/kg and 200 mg/kg) for 4 weeks and the body weight of animals were measured every day. Finally, blood samples were collected and analyzed for glucose and lipid profile levels. RESULTS Administration of green tea extract caused a significant decrease in serum glucose and total cholesterol levels and significantly improved the body weight loss in diabetic rats treated with 200 mg/kg green tea in comparison to diabetic control group. No significant changes were observed in triglyceride (p=0.04), low-density-lipoprotein cholesterol (p=0.000), and high-density-lipoprotein cholesterol levels (p=0.01) following intervention. CONCLUSION It appears that green tea extract had both antihyperglycemic and hypocholesterolmic effects in diabetic rats, although further work is needed to determine their mechanism.