The present study aimed at investigating effect of Gynostemma pentapyllum (GP) extract, administered as a "tea", as add-on therapy with Sulfonylurea (SU) in drug-naive patients with newly diagnosed type 2 diabetes. After screening, all patients received gliclazide MR 30mg and instruction regarding diet and physical exercise for 12 weeks. After 4 weeks treated with gliclazide MR 30mg, the patients was randomized to additional GP tea or placebo tea, 3 g twice daily during 8 weeks. Oral glucose tolerance tests were performed at baseline, after 4 and 12 weeks. Blood tests were taken with the purpose to monitor lipids, kidney and liver function.

In Vietnam, herbal extracts have been used as a long-standing tradition to treat diabetic patients, but effects of these extracts have not been studied adequately. Based on previous results in experimental animal, the investigators have selected the plant Gynostemma pentapyllum (GP), which grows in the mountain region of Northern Vietnam. GP extract had a hypoglycemic effect on mice and rat. In addition, GP has been shown to reduce both hyperglycemia and hyperlipidemia in diabetic Zucker fatty rats.The present study aimed at investigating effect of Gynostemma pentapyllum (GP) extract, administered as a "tea", as add-on therapy with Sulfonylurea (SU) in drug-naive patients with newly diagnosed type 2 diabetes.In addition to monitoring effects plasma glucose regulation, the investigators also studied possible effects on plasma lipids, kidney and liver function as well as body weight and blood pressure.

Inclusion Criteria:

• Newly diagnosed, drug-naive patients with type 2 diabetes
• Fasting plasma glucose (FPG)9.0-14.0 mmol/L
• HbA1C 9-13%

Exclusion Criteria:

• Type 1 diabetes
• Liver failure
• Kidney failure