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

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Gingko Biloba (GBE) & Vascular Health: Michael T. Murray, N.D.
	2006-04-30 02:41:00
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. _________________ JoAnn Guest mrsjo-speakeasy.net http://www.geocities.com/mrsjoguest