Clinical trial NCT00786500: Anti-diabetic Effect of Gynostemma Pentaphyllum Tea in Type 2 Diabetic Patients
Official title: Anti-diabetic Effect of Gynostemma Pentaphyllum Tea in Type 2 Diabetic Patients
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE1
PHASE2
Conditions: Type 2 Diabetes
Keywords: Herbal medicine
Type 2 diabetes
Insulin sensitivity
Insulin secretion
Lead sponsor: Hanoi Medical University
Sponsor class: OTHER
Collaborators: name: Karolinska Institutet
name: Swedish International Development Cooperation Agency (SIDA)
First posted: 2008-11-06
Enrollment: 24
Sex: ALL
Minimum age (years): 40
Maximum age (years): 70
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: The aim of the present study was to investigate the long-term effects on blood glucose concentrations and possible adverse effects of an extract of Gynostemma pentaphyllum (GP). This is a plant growing in the mountain regions of Northern Vietnam and previously being used in traditional medicine. The GP extract, or placebo, was randomized to newly diagnosed patients with type 2 diabetes and administered as a "tea", 3 g two times daily during 12 weeks. All patients received instructions regarding diet and physical exercise. Oral glucose tolerance tests were performed at baseline and then every 4 weeks, and blood tests were taken with the purpose to monitor lipids, kidney and liver function, body weight and blood pressure.

Detailed description: 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 animals, we have selected the plant Gynostemma pentaphyllum (GP), which grows in the mountain region of Northern Vietnam. GP extract had a hypoglycemic effect on mice and rats, and was shown to contain a substance, phanoside, which stimulates insulin secretion. In addition, GP has been shown to reduce both hyperglycemia and hyperlipidemia in diabetic Zucker fatty rats.

The present study aimed at investigate effects of GP extract, administered as a "tea", and compared with placebo in a randomized, double-blind trial in drug-naive patients with newly diagnosed type 2 diabetes. All patients also received instructions about diet and physical exercise. In addition to monitoring effects on plasma glucose regulation, we also studied possible effects on plasma lipids, kidney and liver function as well as body weight and blood pressure.

Eligibility criteria: Inclusion Criteria:

* Newly diagnosed, drug-naive patients with type 2 diabetes
* Fasting plasma glucose (FPG) 7.0-14.0 mmol/l
* HbA1c \> 6%

Exclusion Criteria:

* Type 1 diabetes
* Liver failure
* Kidney Failure

Primary outcomes:
measure: Fasting plasma glucose
timeFrame: 12 weeks
measure: HbA1c (glycosylated hemoglobin)
timeFrame: 12 weeks
Secondary outcomes:
measure: Liver enzymes (ALT, AST)
timeFrame: 12 weeks
measure: Kidney function (S-creatinine, S-BUN)
timeFrame: 12 weeks
measure: Plasma lipids (TG, Cholesterol, HDL-, LDL-)
timeFrame: 12 weeks
measure: Blood pressure
timeFrame: 12 weeks
measure: Body weight (BMI, hip-waist ratio)
timeFrame: 12 weeks
Other outcomes:
Locations:
city: Hanoi
country: Vietnam
facility: National Institute of Gerontology, HMU
Study officials:
affiliation: Karolinska Institutet
name: Claes Goran Ostenson, MD, PhD
role: STUDY_DIRECTOR
References:
citation: Hoa NK, Norberg A, Sillard R, Van Phan D, Thuan ND, Dzung DT, Jornvall H, Ostenson CG. The possible mechanisms by which phanoside stimulates insulin secretion from rat islets. J Endocrinol. 2007 Feb;192(2):389-94. doi: 10.1677/joe.1.06948.
citation: Norberg A, Hoa NK, Liepinsh E, Van Phan D, Thuan ND, Jornvall H, Sillard R, Ostenson CG. A novel insulin-releasing substance, phanoside, from the plant Gynostemma pentaphyllum. J Biol Chem. 2004 Oct 1;279(40):41361-7. doi: 10.1074/jbc.M403435200. Epub 2004 Jun 25.