Gingko Biloba (GBE) & Vascular Health: Michael T. Murray, N.D.

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Gingko Biloba

JoAnn Guest

Jun 16, 2004 21:37 PDT

 

 

Michael T. Murray N.D., Author of

" The Healing Power of Herbs "

 

Gingko Biloba -Key uses:

 

1) Cerebral Vascular insufficiency

(insufficient blood flow to the brain)

2) Dementia

3) Depression

4) Premenstrual syndrome

5) Peripheral Vascular insufficiency (intermittent claudication,

Raynaud's disease, etc.)

6) Multiple Sclerosis

7) Neuralgia and neuropathy

Inner ear dysfunction (tinnitus)

9) Vascular fragility

10) Retinopathy (macular degeneration, diabetic retinopathy, etc.)

11) Impotence

 

Extracts from the leaves of the Gingko tree are used medicinally.

 

The gingko biloba extract is marketed in Europe under these trade

names:

 

Tanakan, Rokan, Ginkogobil, Kaveri, and Tebonin is a well-defined

complex product prepared from the green leaves.

 

Extracts identical to these preparations are available in the United

States as food supplements.

 

The culturing, harvesting and extracting techniques have been

thoroughly standardized and require careful control.

 

The active components of Gingko leaves are the gingko flavone

glycosides and gingko heterosides (flavonoid molecules to which are

attached sugars unique to the gingko) several terpene molecules

unique to gingko (gingkolides and bilobalide, and organic acids.

 

The three major backbone flavonoids of the Gingko biloba are

 

quercetin, kaempferol, and isorhamnetine.

 

The sugar (glucoside components include glucose and rhamnose, which

are present as single sugars or as disaccharides (two sugar

molecules attached to each other.)

Other significant flavonoid components of GBE include

proanthocyanidins (see Grape seed extract)

 

Other constituents of GBE include a number of organic acids. These

compounds contribute valuable properties to the extract by making

the (usually water-soluble) flavonoid and terpene molecules of

ginkgo water soluble.

 

Gingko leaf extracts are now among the 'leading prescription'

medicines in both Germany and France,

where they account for 1.0 and 1.5 percent, respectively, of total

prescription sales.

 

In 1989 alone, more than 100,000 physicians worldwide wrote more

than 10 million prescriptions for GBE.

 

The total extract is more active than its single components of GBE-

an explanation that is well supported in more than 300 clinical and

experimental studies utilizing the extract.

 

Tissue effects

 

Ginkgo biloba extract exerts a profound, widespread influence on

tissue, including membrane-stabilizing, antioxidant, and free

radical- scavenging effects. Ginkgo biloba extract also enhances the

utilization of oxygen and glucose.

 

Cellular membranes provide the first line of defense in maintaining

the " integrity " of the cell.

 

Largely composed of fatty acids (phospholipids), cellular membranes

also serve as fluid barriers, exchange sites, and electrical

capacitors.

 

These membranes are fragile and vulnerable to damage especially the

lipid peroxidation induced by oxygenated free radicals. Gingko is an

extremely effective inhibitor of lipid peroxidation of cellular

membranes.

 

Red blood cells provide excellent models for evaluating the effects

of substances on membrane functions.

 

Red blood cell studies utilizing GBE have demonstrated that in

addition to directly stabilizing membrane structures and scavenging

free radicals,

GBE also enhances membrane transport of potassium into (and

sodium out of) the cell by " activating " the sodium pump

(Very beneficial in controlling High blood pressure).

 

In essence, GBE leads to better membrane polarization. This is

particularly important in excitable tissues, such as nerve cells.

--

Vascular effects

 

The mechanisms of GBE's vascular effects have been investigated

utilizing a number of " in vivo " and " in vitro " techniques. Isolated

vessel techniques allow the effects of GBE on different parts of the

vascular system to be isolated, while in vivo studies provide

information on the total circulatory phenomena (i.e., GBE's ability

to ncrease the perfusion rate to various regions).

 

Gingko biloba extract stimulates greater tone in the venous system,

thus aiding the dynamic clearing of toxic metabolites that

accumulate during " ischemia "

(times of insufficient oxygen supply).

 

Gingko biloba extract normalizes circulation by producing tonic

effects. These effects are much more apparent in an ischemic

vascular

area than in a normally perfused area.

 

It is truly remarkable that a substance can simultaneously combat

the phenomena resulting from

vascular spasm and with the same efficiency; restore circulation to

areas subject to vasomotor paralysis.

 

The importance of this dual action is becoming more apparent in

cerebral nsufficiency as single-direction drugs (i.e. vasodilators),

can often aggravate the condition by preferentially dilating the

healthy

areas, thereby deflecting blood and oxygen AWAY from the ischemic

area.

 

--

Future applications of Ginkgo Biloba extract

 

Experimental studies as well as some preliminary clinical evidence

indicate that GBE may be of benefit in cases of angina, congestive

heart failure, and in acute respiratory distress syndrome.

 

Its action on inhibiting platelet activating factor may also make it

useful in the treatment of conditions other than allergies,

including various types of shock, thrombosis, graft protection

during

organ transplantation, multiple sclerosis, and burns.

 

Clinical research shows that GBE should be taken consistently for at

least 12 weeks to be effective. Although most people report benefits

within 2 to 3 weeks, some may take longer to respond.

 

Gingko biloba leaf extract is extremely safe and side effects are

uncommon.

--

Nerve cell effects

 

The membrane stabilizing and free radical scavenging effects of GBE

are perhaps most evident in the brain and nerve cells. Brain cells

contain the highest percentage of unsaturated fatty acids in their

membranes of any cells in the body, making them extremely

susceptible to

free radical damage.

 

The brain cell is also extremely susceptible to hypoxia. Unlike most

other tissues, the brain has very little energy reserve. Its

functions require large amounts of energy in the form of a constant

supply of glucose and oxygen.

 

Diminished circulation to the brain sets

off a set of chain reactions that disrupt membrane function and

energy production and ultimately lead to cellular death.

 

Gingko biloba extract is remarkable in its ability to prevent

metabolic disturbances in experimental models of insufficient blood

supply to the brain.

 

It accomplishes this by enhancing oxygen utilization and increasing

cellular uptake of glucose, thus restoring energy production.

 

Particularly interesting is GBE's ability to normalize the

circulation in the areas most affected by micro embolization, namely

the

hippocampus and striatum.

 

Briefly, GBE promotes an increased nerve transmission rate, improves

synthesis and turnover of brain neurotransmitters, and normalizes

acetylcholine receptors in the hippocampus (the area of the brain

most affected by Alzheimer's disease.)

---

Peripheral arterial insuffiency

 

Peripheral arterial disease has as its primary lesion the same

cholesterol-containing plaque that is responsible for other

condition associated with atherosclerosis, for example, coronary

artery

disease nd cerebral vascular insuffiency.

 

In peripheral arterial insufficency the arterial obstruction or

narrowing causes a reduction in blood flow during exercise or at

rest.

Clinical symptoms cause a reduction in blood flow during exercise or

at rest. Clinical symptoms are caused by the consequent ischemia.

 

The most common symptom is a pain on exertion-intermittent

claudication.

The pain usually occurs in the calf and is described as a cramp or

tightness, or severe fatigue.

 

The pain is usually bilateral.

The pain is caused not only by reduced oxygen delivery, but also by

an increase in the production of toxic metabolites and cellular free

radicals.

 

These free radicals accumulate and react with the lipid constituents

of the cell membrane.

 

Pain at rest indicates serious reduction in resting blood flow. It

is an obvious sign of severe disease. The pain may be localized to

one

or more toes, or it may have a stocking-type distribution. The pain

is usually described as burning or gnawing and is generally worse at

night.

 

A purple color or pallor of the extremity is usually apparent. In

moderate to sever narrowing of the artery, the skin can become dry,

scaly,

and shiny. The hair may disappear, and toenails may become brittle,

ridged, and deformed.

 

In nine double-blind, randomized clinical trials of GBE versus

placebo in two matched groups of patients with peripheral arterial

insufficiency of the leg, GBE was shown to be quite active and

superior

to placebo

(eight studies) and equal to pentoxifylline (one study).

 

Not only were measurements of pain-free walking distance (75 to 110

percent_ and maximum walking distance 52 to 110 percent)

dramatically increased, but plethyamographic and Doppler ultrasound

measurements demonstrated increased blood flow through the affected

limb; blood lactate levels also dropped.

 

The demonstration that Ginkgo biloba extract improves limb blood

flow as well as walking tolerance (in studies following strict

methodology and sufficient patients for reliable evaluation)

indicates that GBE is

far superior to peritoxifylline and standard medical therapy in the

treatment of peripheral arterial insufficiency.

 

This includes other peripheral vascular disorders such as diabetic

peripheral vascular disease, Raynaud's disease, acrocyanosis, and

postphlebitis syndrome.

 

The longer GBE is used, the greater the benefit.

 

The following table

summarizes a 2-year trial of GBE (160 mgs daily) in the treatment of

peripheral arterial disease (Fontaine stage IIb). Pain free walking

distance increased by 300 percent.

---

Platelet effects

 

Gingko biloba extract and isolated ginkgolides have profound effects

on platelet function, including inhibition of platelet aggregation,

inhibition of platelet adhesion,

and degranulation (release of

allergic and inflammatory components).

 

These effects appear to be due to direct membrane and antioxidant

effects, increase synthesis of prostacyclin and the antagonism of a

substance known as platelet-activating factor (PAF).

 

Gingko biloba extract and the ginkgolides have been shown to be

potent inhibitors of PAF. Platelet-activating factor is a potent

stimulator of platelet aggregation and degranulation.

 

It is also involved in many inflammatory and allergic processes

including neutrophil activation, increasing vascular permeability ,

smooth muscle contraction including bronchoconstriction, and

reduction in coronary blood flow. Gingko extract and ginkgolides

compete

with PAF for binding sites and inhibit the various events induced by

PAF.

These actions may be responsible for many of the clinical effects of

GBE.

 

Clinical Applications

 

Ginkgo biloba extracts primary clinical application has been in the

treatment of vascular insufficency. In more than fifty double blind

clinical trials, patients with chronic cerebral (brain) arterial

insufficiency and patients with arterial insufficiency have

responded favorably to GBE.

 

 

" The Healing Power of Herbs "

By Michael T. Murray, N.D.

Co-author of " Encyclopedia of Natural Medicine "

 

Warning-Disclaimer Prima Publishing has designed this book to

provide information in regard to the subject matter covered. It is

sold with the understanding

that the publisher and the author are not liable for the

misconception or misuse of information provided.

 

Every effort has been made to make this book as complete and as

accurate as possible.

The purpose of this book is to educate. The author and Prima

Publishing shall have neither liability nor responsibility to any

person or entity with respect to any loss, damage or injury caused

or alleged to be

caused directly or indirectly by the information contained in this

book.

 

The information presented herein is in no way intended as a

substitute for medical counseling.

_________________

 

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