Ginkgo biloba L. Ginkgo, Maidenhair tree
Family: Ginkgoaceae
Description: “Deciduous tree with conical habit when young, and fan-shaped leaves up to 12cm across, which turn yellow in autumn. Tiny female flowers are sometimes followed by foetid, plum-like fruits, about 2.5cm long. H 40m, S 20m.” (Bown, 1995: 134)
Habitat: Native to central China.
Harvest: Leaves are picked as they change colour in autumn and dried for use in tinctures, etc. (Bown, 1995).
Part used: Leaves.
Dosage: 1:5 Tincture: 1-5ml tds, Fluid Extract: 1ml tds, Dried: 2-3g tds, Standardized Extract: 50:1 concentrates: 40mg tds (AD).
Character: Sweet, bitter, astringent, neutral (Ody, 1993)
Actions:
-ANTI-PAF activity,
-ANTIOXIDANT,
-TISSUE PERFUSION ENHANCER,
-CIRCULATORY STIMULANT,
-MEMORY AND COGNITIVE FUNCTION ENHANCER.
Indications:
-Disorders and symptoms due to restricted cerebral blood flow*, eg. memory or cognitive impairment, dizziness, tinnitus, headaches, anxiety/ depression, fatigue, stroke;
-Vertigo, acute cochlear deafness*;
-Early stages of primary degenerative dementia (Alzheimer type)*;
-Disorders due to restricted retinal blood flow*; congestive dysmenorrhoea*; effects of high altitude or hypoxia*.(all above Mills and Bone, 2000)
-COGNITIVE CHANGES, ESPECIALLY ASSOCIATED WITH AGE, EG. POOR MEMORY. May be used by students facing exams (AD handout).
-Disorders due to restricted peripheral blood flow, incl. diabetic vascular disease, atherosclerosis, Raynaud’s syndrome**.(Mills and Bone, 2000)
-Varicose ulcers* (AD handout), any peripheral arterial disease.
-Anti-PAF activity useful in treatment of asthma, allergic reactions, immunological reactions, shock, ischaemia [local anaemia due to mechanical obstruction of blood supply, usu. narrowing of arteries], thrombosis**. (Mills and Bone, 2000)
-Any condition where circulatory insufficiency may be factor such as Parkinson’s disease (AD handout).
Safety: Very low risk; only 1.6% rate of side effects, mainly digestive problems, eg. diarrhoea, and headache (AD handout).
Contra-indications: Patients prescribed Warfarin or aspirin.
Key Constituents:
5-7% ginkgolides: terpene lactones
22-27% flavone glycosides
Pharmocology: Extensive studies especially demonstrating PAF antagonism, effects on ischaemia and blood flow, antioxidant activity and effects on memory and/ or learning. See Mill and Bone, 2000: 405-408 and AD handout for details.
Clinical trials: Again extensive; especially re: cerebral insufficiency and stroke, dementia, tinnitus and vertigo, peripheral arterial disease and intermittent claudication [limping due to ischaemia of muscles, mainly calf], varicose veins and venous insufficiency. See Mills and Bone, 2000: 408-414 and AD handout.
Toxicology: Studies show no evidence of organ damage or impairment of hepatic or renal function; no mutagenic activity. (Mills and Bone, 2000).
History: Prehistoric, probably died out in Europe in Ice Age, survived unchanged for about 150 million years as cultivated trees in Far Eastern ‘temple gardens’ (Ody, 1993). First tree to reflower after Hiroshima (AD).Name derives from Japanese gin, ‘silver’ and kyo, ‘apricot’. Chinese medicine has traditionally used Ginkgo nuts as an anti-asthmatic and against polyuria (Mills and Bone) but use of leaves as circulatory stimulant comes only from studies conducted from 1960s. In 1988, doctors in Germany wrote out 5.4 million prescriptions for Ginkgo, more than for any other drug and in addition to any OTC purchases (AD handout).
Traditional and Practitioner sources:
“significant improvement in mental states, emotional liability, memory, and tendency to tire easily, have been reported…” Rudolph Weiss, 1985 (0dy, 1993: 64)
“INFUSION Make with 50g dried leaves to 500ml water, and take for arteriosclerosis and varicose conditions. Use as a wash for varicose ulcers or haemorrhoids.” Penelope Ody (1993: 64)
“ARTERIOSCLEROSIS Apart from attending to dietary factors, the herbalist might use peripheral vasodilatory remedies, particularly hawthorn, limeflowers and gingko, for their ability to improve circulation and oxygenation.” Simon Mills (Mills, 1993:560)
