Extract of Ginkgo Biloba (EGB 761) and Vascular Function
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|ClinicalTrials.gov Identifier: NCT00029991|
Recruitment Status : Completed
First Posted : January 30, 2002
Last Update Posted : August 18, 2006
|Condition or disease||Intervention/treatment||Phase|
|Intermittent Claudication Peripheral Vascular Disease||Drug: Gingko Biloba (Herb)||Phase 1 Phase 2|
This study will determine if a highly standardized herbal extract of the leaves of the Ginkgo Biloba tree, widely used in Europe for two decades, will benefit patients who have pain on walking due to narrowing of the arteries of the legs. A few studies done about ten years ago in Germany appeared to benefit such patients. It is important to confirm these findings and to learn how it may work. Animal studies suggest that this extract, known as EGb 761, works through very strong antioxidant mechanisms. A second action suggested is that it stimulates cells lining the inside of the arteries to produce the compound nitric oxide. These cells, known as endothelial cells, are susceptible to damage by blood cholesterol, smoking or high blood pressure and, when damaged, will allow cholesterol to deposit in arteries. Antioxidants can prevent the endothelial cell damage, therefore it is very important to know if EGb 761 works through that mechanism. These cells also produce nitric oxide naturally as a defense against injury, so an EGb 761 effect on nitric oxide would also provide benefit. Consumption of Gingko Biloba products, many of uncertain purity, is increasing rapidly in the United States. Confirmation of its benefits, derived largely from Europe, is important to protect the health of the American people and to find new and inexpensive remedies for common problems, such as narrowed arteries in the legs. If benefit is found for this problem, then it will be highly likely that the atherosclerotic deposits that cause heart attacks and many strokes may also be preventable or treatable with this compound. Any benefit found will also lead to future studies to determine which constituents of the mixture now present in EGb 761 confers the benefit. If these actions, or others, were discovered, then this herbal product could become used with greater confidence.
This double-blind study will randomly assign parcicipants to receive 4 months of either EGb 761 at 320 mg/day or placebo. Improving walking distances by 30% or greater is the major goal. A second goal will test the safety of EGb 761 through careful examination of liver and kidney function and other measures of general health. Also, a thorough search will occur for antioxidant actions and for changes in endothelial cell nitric oxide production. Two study visits will occur at baseline, and two will occur at Month 4.
|Study Type :||Interventional (Clinical Trial)|
|Estimated Enrollment :||100 participants|
|Intervention Model:||Parallel Assignment|
|Official Title:||Extract of Ginkgo Biloba (Egb 761) and Vascular Function|
|Study Start Date :||September 2000|
|Estimated Study Completion Date :||July 2005|
- Maximal and pain-free walking distance
- Flow mediated vasodilation of the brachial artery
- Antibodies to epitopes of oxidized LDL
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00029991
|United States, California|
|Stanford, California, United States, 94305|
|Principal Investigator:||John W. Farquhar, MD||Stanford University|