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.