Ginkgo biloba is the only existing deciduous tree in Ginkgoaceae as a symbol of vitality. Since it has maintained the current feature which is identical to the one in Paleozoic period since its first appearance approximately 250 million years before passing through the crustal movements of 60 million years and many times of glacial periods, it is often considered as the symbol of strong vitality. In the ginkgo extracts obtained from the mature green leaves of Ginkgo biloba, large amount of bioactive substances are found. The major compounds of Ginkgo leaves are known as kaempferol and quercetin which are flavonoid compounds, and bilobalide and ginkgolide A, B, C, D, M, and J which are terpene compounds. Also, omega-3-fatty acids are included as minor compounds.
Fresh leaves or dried leaves, and fruits without crust are all referred to as Ginkgo. Either cultivated ones or wild ones are harvested by hands or machines. Leaves are dried and pressed in ball shape. The dried extracts obtained from dried leaves are washed by acetone/water to become the final product. At this time, concentrates or separating additives are not used. In oriental medicine, fruits are called as Baekgwa, crust as Baekgwa Supi, and roots as Baekgwa Geun.
Ginkgolide B is a potential inhibitor of Platelet activating factor (PAF) which has an important role in the platelet coagulation process independent from arachidonic acid. Ginkgolide B antagonizes the process by inhibiting the binding of PAF and its receptor. As a result, T lymphocytes proliferate to release cytokines and inhibit PAF-induced bronchoconstriction and airway activity promotion. PAF induces inflammation and change in blood infiltration.
Ginkgo extracts prevent or treat acute cerebral partial anemia with higher effectiveness when used in preventive purpose. Ginkgo extracts relieves the cerebral damages from partial anemia. When they are administered prior to the revascularization of the intestinal partial anemia, the biomarker level is decreased and mucosal damages are relieved.
In an experiment on mice, oral administration of Ginkgo extracts has inhibited cholinergic activity on the lack of memory to protect the brain from beta-amylase. EGb761 which is a Ginkgo extract exhibits neuro-protective effects inhibiting oxidative damages and enhancing cell viability to have effects on dementia.
Ginkgo mostly helps vascular dementia and peripheral vascular diseases with inhibitory activity on cholinesterase. Also, it inhibits the neutrophilic infiltration and increases the blood flow to eventually inhibit the ischemic progress of dementia.
EGb1, a Ginkgo extract, enhances blood property and tissue metabolism to enhance recognition ability and suppress dementia symptoms arising from the partial anemia. In vivo, EGb1 removes free radicals, protects neuronal necrosis from partial anemia, maintains hippocampal mossy fiber system, absorbs high-affinity hippocampal cholines, reduces the number of hippocampal glucocorticoid receptors, and extends neural plasticity while inhibiting the deficiency in cognitive function bringing damages to the brain.
Flavonoids and Ginkgolides included in EGb761 are involved in the removal of free radicals and anti-oxidant activity to lower the reactive oxygen species (ROS) level and inhibit the lipid oxidation on the cellular membrane. The Ginkgo flavonoids exhibit anti-oxidant activity while protecting the cells from ischemia. Oxidized lipids bring the cellular generation, blood vessel damage, and loss of neurons to lead to dementia. Anti-oxidant activity and cellular membrane stabilization increase the cerebral resistance to the hypoxia.
Ginkgo extracts show superior anti-psychotic effects in schizophrenia patients, especially on positive symptoms which is estimated to attribute to the anti-oxidant activity of Gingko.
It directly acts on ∂- adrenoceptor to show antispasmodic activity. Also, it antagonizes the hyperpolarization and adrenergic system via signaling transmission pathway and cAMP in external membrane to release smooth muscles.
Ginkgo extracts show liver protective effects against acute pulmonary damages. In an experiment verifying the effects of ginkgetin on cytooxyagenase in cells and on skin inflammation in vitro, it showed inhibitory action on phopholipase A2 in mice and potential anti-arthritic activity as well as analgetic effect in reinforcing agent-induced arthritis. Also, it reduces cycloxygenase-2 in vivo which is related to the anti-inflammatory activity on skin inflammation. The liver weight, phospholipid concentration, and content of cytochrome P450 all have significantly increased. On the other hand, the activity of glutathlone S-transferase and the concentrations of CYP2B1/2 and CYP3A1 have largely decreased. In an experiment in mice, Ginkgo has significantly increased the heart rate and contractile force of separated atriums. In order to verify the active compounds of Ginkgo extracts, Ginkgolide B, quercetin, and amentoflacone were tested on atriums. Here, it was proved that ginkgolide and amentoflacone significantly increase the heart rate. As a result, it is a type of dietary intakes with effectiveness on amentoflacone.
In amilotropic side sclerotic gene transplanted mice, Ginkgo extracts exhibited gender-specific neuronal protective effects to implicate the potential effectiveness in the treatment of ALS patients. In the study on the effects of Ginkgo on the attention deficit hyperactivity disorder (ADHD), the combination treatment of Ginkgo and Ginseng largely improved the ADHD symptoms. However, more studies are needed to support the treatment of ADHD.
In the traditional oriental medicine, it is used to treat coronary artery disease, chest pain, heart pain, palpitation, hypertension, chronic cough, asthma, buzzing in the ear, and angina.
Post-surgery patients in recovery must consult to the experts before administration.