Ginkgo biloba – Ginkgo, Gingko
Ginkgoaceae family
The part used in medicine is the ginkgo leaf, harvested in the autumn, when it begins to turn yellow, and dried in natural conditions (shaded and ventilated).
Ginkgo – appearance and origin:
An angiosperm from the Ginkgoceae family, found in the wild in East China, grown in the whole of East China, in North America, New Zealand, Europe, and in Poland. In Poland, unique specimens reach over 100 years and 20 m in height. They can be found i.a. in historic parks and gardens in Warsaw, Łańcut, Gdańsk Wrzeszcz, Gdańsk Oliwa (Oliva Park) and the Botanical Garden of the Maria Curie-Skłodowska University in Lublin.
The ginkgo tree crown is of regular shape, loosely branched, initially tapering, but gets wider and cylindrical with time. The shoots are often thicker at the tip than at the base and have different length. Long shoots are bare, yellow-brown, with alternate leaves. Short shoots are numerous on branches. They have a cylindrical shape and are thickly covered with leaves (3-5). There are many marks left by detached leaves and shells. The ginkgo leaf is 5-8 cm in width. The veins are dichotomous (no main nerve) and resembles a Japanese fan. Young leaves are bright green, later dark green, and in the autumn they become yellow before they fall. Ginkgo is dioecious and anemophilous. The stamen flower head (clustered in hanging catkins) and the pistil flower head (embedded in pairs in long pedicels with 2 ovules) are found on the short shoots. The tree blooms in May and June, producing inedible fruit resembling plums, 2,5-3 cm in diameter. The fruit have a strong, unpleasant smell. The seed of the fruit is edible.
Ginkgo – effect and use:
The active substances in ginkgo biloba leaves are numerous and unique. The most important include flavonoids and terpenes. The flavonoids are mono-, di- and triglycosides of quercetin, cempherol and isorhamnetin, and also glycoside derivatives with coumaric acid. The flavonoids include also biflavones: amentoflavone and its methylated derivatives, monomeric flavan derivatives, such as (+)catechin, (-)epicatechin and others, oligo- and polymeric procyanidins. The main terpenes are diterpene trilactones, called glycolides (A, B, C and J), which are distinguished by the number and placement of hydroxyl groups, and bilobalid (sesquiterpene trilactone). The leaves also contain organic acids, sitosterols, polysaccharides, cyclitols (sugar alcohol), carotenoids, alkylophenols (cardanols and urushiols), and alkylphenolic acids (ginkgolic acid).
Dementia symptoms
Ginkgo extract is recommended for treating various symptoms of dementia (generally degrading, vascular or a combination of the two), cerebral insufficiency, neurosensory disorders (such as dizziness, tinnitus), and for symptomatic treatment of peripheral artery disease.
Antioxidation
Thanks to flavonoids, the so-called free radical scavengers, ginkgo extract counteracts hydroxyl free radicals and superoxide anions, which are the main cause of skin aging, cancer and many other lesions. These properties also allow to inhibit the oxidation of the LDL fraction (Low-density lipoproteins). As a result, ginkgo helps maintain proper cholesterol levels and protects the cardiovascular system. It was found that ginkgo significantly reduces the release of mioglobin and greatly influences myosin relase, which is crucial in treatment of stress and cardiovascular surgeries.
Circulatory failure
In case of post-ischemic arrhythmia, ginkgo extract exhibits antiarrhythmic activity and protects the body against the oxidising damage of the artery blood flow. This results from the inhibition of oxygen free radicals which prevents the loss and oxidation of ascorbate (vitamin C), an endogenous antioxidant of the myocardium. It was also found that thanks to bilobalid, ginkgo may delay the activation of glycolysis during endothelial cell hypoxia and may also help mitochondrial respiration. Ginkgo extract improves artery blood flow, plasma viscosity and reduces hyperfibrigenemia. Also improves blood flow in skin blood vessels and their elasticity, thanks to which it has found its use in cosmetics dedicated to sensitive skin, prone to capillary bursting.
Platelet-activating factor
Ginkgolides contained in ginkgo leaves are antagonists of the platelet-activating factor (PAF). The most active one is ginkgolide B which improves blood flow and microcirculation. It also inhibits the production of superoxides activated by PAF and cytokines. The tumor necrosis factor is probably related to pathogenesis of neurodegeneration.
Central nervous system
Ginkgo extracts reduces the fluidity of neuron membrane, which is related to peroxidation (forming superoxide groups) of membrane lipids, caused by ascorbic acid/Fe2+. Thus, the transport of the neurotransmitter dopamine, responsible for the motor system, movement coordination and muscle contraction, which is crucial for emotional and learning processes. Ginkgo also helps with the regeneration of receptor sensitivity to serotonin, the "happy hormone", influencing the mood, sleep, sexual needs, impulses and appetite. Importantly, the ginkgo extract also benefits the memory, psychomotor functions and intellectual capacity.
Aphrodisiac
The ginkgo extract has been found to increase the blood floow in the genitalia which improves sexual function (libido, erection, orgasm disorders). It is possible due to the increased nitric oxide production, informing blood vessels of relaxation which is crucial in achieving erection.
Optic nerve diseases
A significant increase in the velocity of opthalmic arteriol flow has been observed, with no side effects, changes of arterial pressure, heart rate or intraocular pressure. Ginkgo is therefore proven to be appropriate for treating glaucomatous optic neuropathy and other ischemic optic nerve diseases.
Other effects
The ginkgo extract prevents acute altitude sickness (headache, dizziness, shallow breathing, nausea, vomiting, etc.); cold sensations related to circulation issues (numb limbs, cramps, long-lasting pain, edema of limbs). It counteracts edema, both of vascular and cytotoxic origin (e.g. after radiotherapy). For people with coagulative disorders or taking medication reducing platelet aggregation (e.g. aspirin), ginkgo products should be taken with special caution. What is also important is the low content of the harmful ginkgolic acids, also found in poison ivy (Rhus toxicodendron). Ginkgolic acid is an allergen and can induce contact dermatitis, especially on the skin. The acid is found mainly in the seed husks, and ginkgo leaves can contain trace amounts. It is important to not exceed a low level of ginkgolic acids. According to safety requirements, their content in ginkgo products should not exceed 5 ppm.
The ginkgo extract is used for treatment of many diseases of the nervous and circulatory systems, as well as for cosmetics. Ginkgo biloba holds enormous potential for the future.
PL