Study Effects of Ginkgo Biloba Extract on Endothelial Cell Function and Genetic Effects on the Response to Ginkgo Biloba Extract in Diabetic Patients With Stable Coronary Artery Disease

December 22, 2009 updated by: Taipei Veterans General Hospital, Taiwan

Type 2 diabetes is associated with a markedly increased risk for atherosclerotic coronary arteries and cerebrovascular diseases. The major cause of death in diabetic patients is cardiovascular disease in the world including Taiwan. Atherosclerosis is a progressive disease characterized by the response of the vessel wall to chronic, multifactorial injury, which leads ultimately to the formation of atheromatous or fibrous plaques. Endothelial dysfunction is thought to be the initial stage of atherosclerosis. Endothelial dysfunction leads to impaired control of vascular tone, a decreased in the release of anti-inflammatory factors and reduced availability of nitric oxide. Endothelial dysfunction portends diabetic vasculopathy. The loss of intact endothelial integrity and function sets in motion a cascade of serial events that lead to atherosclerosis and cardiovascular complications.

The standard extracts of G. biloba leaves [G. biloba extract (GBE)] are now demonstrated the cardiovascular, cerebrovascular and neuroprotective effects. The mixture of biologically active ingredients in GBE accounts for the pleiotropic effects, including antioxidant effects, inhibition of platelet aggregation and thromboxane B2 production, vasodilation and modulation of cholesterol metabolism. Clinically, GBE was widely used in management of vertigo、dementia and improving peripheral circulation. In our previous study, ginkgo biloba extract inhibits tumor necrosis factor-alpha-induced reactive oxygen species generation, transcription factor activation, and cell adhesion molecule expression in human aortic endothelial cells. In addition, the similar benefit of prevention atherosclerosis was also found in animal study.

Heme oxygenase-1 (HO-1) is a factor associated with higher risk of developing some vascular disease and also a rate-limiting enzyme in heme degradation, leading to the generation of free iron, biliverdin, and carbon monoxide (CO). CO exerts potent antiproliferative and anti-inflammatory effects in the vascular walls, thereby influencing neointimal formation after vascular injury. In addition, biliverdin is subsequently metabolized to bilirubin by the enzyme biliverdin reductase. Therefore, induction of HO-1 elicits potent anti-inflammatory, antiproliferative, antithrombotic, and antioxidant effects in the circulation via the generation of CO and bilirubin. Interestingly, recent study found that a long guanidine thymidine dinucleotide repeat [(GT) n≧ 30] in the HO-1 promotor, which is linked to impaired inducibility, is associated with a higher frequency of vascular access failure.

In the present study, we will investigate the effect of GBE on recovering endothelial dysfunction and inflammation in diabetic patients with stable coronary artery disease. In particularly, we intend to determine whether the GBE modulates the HO-1 expression and investigate whose genotyping including some candidate gene about atherosclerosis and hypertension will have most therapeutic effect of GBE.

Study Overview

Study Type

Interventional

Enrollment (Anticipated)

60

Phase

  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

      • Taipei, Taiwan, 11217
        • Taipei Veterans General Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 80 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Thirty type 2 diabetes mellitus with stable coronary disease
  • Aged 18-80 year-old

Exclusion Criteria:

  • Previous underwent coronary artery bypass surgery or percutaneous angioplasty
  • Under insulin injection patients
  • Renal or hepatic function impairment
  • Pregnant women
  • Poor BP control(BP>175/105 mmHg)

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Number of endothelial progenitor cells, endothelial function(FMD)
Time Frame: 3 months
3 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: Jaw-Wen Chen, MD, Division of Cardiology, Taipei Veterans General Hospital
  • Principal Investigator: Chin-Chou Huang, MD, Division of Cardiology, Taipei Veterans General Hospital

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

October 1, 2009

Primary Completion (Anticipated)

November 1, 2010

Study Completion (Anticipated)

December 1, 2010

Study Registration Dates

First Submitted

December 20, 2009

First Submitted That Met QC Criteria

December 22, 2009

First Posted (Estimate)

December 23, 2009

Study Record Updates

Last Update Posted (Estimate)

December 23, 2009

Last Update Submitted That Met QC Criteria

December 22, 2009

Last Verified

December 1, 2009

More Information

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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Clinical Trials on Ginkgo Biloba Extract (GBE)

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