Title
Additional information to the in vitro antioxidant activity of Ginkgo biloba L.
Author
Lugasi A; Horvahovich P; Dworschák E
Source
Phytother Res, 1999 Mar, 13:2, 160-2
Abstract
The in vitro antioxidant and free radical scavenging activity of the ethanol extract from
Ginkgo biloba L. was examined in different systems. The extract showed
hydrogen-donating ability, reducing power, copper-binding property, free radical scavenging
activity in a H2O2/.OH-luminol system and it could prevent the autoxidation of linoleic
acid. All these properties are involved in the overall antioxidant activity of Ginkgo biloba
which makes it suitable for the prevention of human disease in which free radicals play an
important role.

Title
The protective effect of Ginkgo biloba extract on CCl4-induced hepatic damage.
Author
Ozenirler S; Dinçer S; Akyol G; Ozogul C; Oz E
Source
Acta Physiol Hung, 1997, 85:3, 277-85
Abstract
The aim of this study was to evaluate the protective effect of Ginkgo biloba extract on
CCl4-induced hepatic damage in rats. Hepatic malondialdehyde, glutathione and
hydroxyproline levels and histopathologic alterations in liver specimens were assessed. 200
mg/kg/day Ginkgo biloba extract were given orally to the animals for 10 days, then a single
dose of 2 ml/kg b.w. carbon tetrachloride was, administered intraperitoneally. Ginkgo biloba
extract treatment reduced hepatic malondialdehyde levels significantly (p < 0.05), but did not
alter glutathione (p > 0.05) and hydroxyproline levels (p > 0.05). The light and electron
microscopic findings showed that Ginkgo biloba extract limited the CCl4-induced
hepatocyte necrosis and atrophy. These results suggest that this extract may protect the
hepatocytes from carbon tetrachloride-induced liver injury.

Title
The efficacy of Ginkgo biloba on cognitive function in Alzheimer disease.
Author
Oken BS; Storzbach DM; Kaye JA
Source
Arch Neurol, 1998 Nov, 55:11, 1409-15
Abstract
OBJECTIVE: To determine the effect of treatment with Ginkgo biloba extract on objective
measures of cognitive function in patients with Alzheimer disease (AD) based on formal
review of the current literature. METHODS: An attempt was made to identify all English
and non-English-language articles in which G. biloba extract was given to subjects with
dementia or cognitive impairment. Inclusion criteria for the meta-analysis were (1)
sufficiently characterized patients such that it was clearly stated there was a diagnosis of AD
by either Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition, or
National Institute of Neurological Disorders and Stroke-Alzheimer's Disease and Related
Disorders Association criteria, or there was enough clinical detail to determine this by our
review; (2) clearly stated study exclusion criteria, ie, those studies that did not have stated
exclusions for depression, other neurologic disease, and central nervous system-active
medications were excluded; (3) use of standardized ginkgo extract in any stated dose; (4)
randomized, placebo-controlled and double-blind study design; (5) at least 1 outcome
measure was an objective assessment of cognitive function; and (6) sufficient statistical
information to allow for meta-analysis. RESULTS: Of more than 50 articles identified, the
overwhelming majority did not meet inclusion criteria, primarily because of lack of clear
diagnoses of dementia and AD. Only 4 studies met all inclusion criteria. In total there were
212 subjects in each of the placebo and ginkgo treatment groups. Overall there was a
significant effect size of 0.40 (P<.0001). This modest effect size translated into a 3%
difference in the Alzheimer Disease Assessment Scale-cognitive subtest. CONCLUSIONS:
Based on a quantitative analysis of the literature there is a small but significant effect of 3- to
6-month treatment with 120 to 240 mg of G. biloba extract on objective measures of
cognitive function in AD. The drug has not had significant adverse effects in formal clinical
trials but there are 2 case reports of bleeding complications. In AD, there are limited and
inconsistent data that preclude determining if there are effects on noncognitive behavioral
and functional measures as well as on clinician's global rating scales. Further research in the
area will need to determine if there are functional improvements and to determine the best
dosage. Additional research will be needed to define which ingredients in the ginkgo extract
are producing its effect in individuals with AD.

Title
Ginkgo biloba for antidepressant-induced sexual dysfunction.
Author
Cohen AJ; Bartlik B
Source
J Sex Marital Ther, 1998 Apr, 24:2, 139-43
Abstract
In an open trial ginkgo biloba, an extract derived from the leaf of the Chinese ginkgo tree
and noted for its cerebral enhancing effects, was found to be 84% effective in treating
antidepressant-induced sexual dysfunction predominately caused by selective serotonin
reuptake inhibitors (SSRIs, N = 63). Women (n = 33) were more responsive to the sexually
enhancing effects of ginkgo biloba than men (N = 30), with relative success rates of 91%
versus 76%. Ginkgo biloba generally had a positive effect on all 4 phases of the sexual
response cycle: desire, excitement (erection and lubrication), orgasm, and resolution
(afterglow). This study originated from the observation that a geriatric patient on ginkgo
biloba for memory enhancement noted improved erections. Patients exhibited sexual
dysfunction secondary to a variety of antidepressant medications including selective
serotonin reuptake inhibitor (SSRIs), serotonin and nonrepinephrine reuptake inhibitor
(SNRIs) monoamine oxidase inhibitor (MAOIs), and tricyclics. Dosages of ginkgo biloba
extract ranged from 60 mg qd to 120 mg bid (average = 209mg/d). The common side
effects were gastrointestinal disturbances, headache, and general central nervous system
activation. The article includes a discussion of presumed pharmacologic mechanisms,
including effects on platelet activating factor, prostaglandins, peripheral vasodilatation, and
central serotonin and norepinephrine receptor factor modulation.

Title
Therapeutic value of Ginkgo biloba in reducing symptoms of decline in mental function.
Author
Curtis Prior P; Vere D; Fray P
Source
J Pharm Pharmacol, 1999 May, 51:5, 535-41
Abstract
The Chinese tree Ginkgo biloba or "maiden hair tree" is extensively cultivated for the
exploitation of the medicinal properties of its leaves. From these, a well-defined extract
designated "EGb 761" has been developed, which was commercialized initially as Tanakan,
Tebonin and Rokin; a similar product, Kaveri (LI 3170), also exists. The major therapeutic
applications for these products are "cerebral insufficiency", other cerebral disorders,
neurosensory problems and peripheral circulatory disturbances. Four primary concepts of
action have been proposed to explain the pharmacotherapeutic benefits of EGb761; these
are: vasoregulatory, cognition-enhancing, stress-alleviating, and gene-regulatory. These
actions are believed to be realized through the principal active ingredients, flavonoids and the
terpenoids ginkgolides and bilobalide acting simultaneously in concert, combination and
synergy, so-called polyvalent action. It has been proposed that EGb761 may improve the
memory of healthy volunteers, and in an assessment meta-analysis of forty clinical studies,
it was reported that Ginkgo was able to improve the twelve different symptoms comprising
'cerebral insufficiency', all of which are manifest in the elderly. These were supported in a
second major study, using LI1370. However, in both instances, the evidence was largely
based upon the results of self-assessment questionnaires. Latterly, in a large double blind
study of men and women with the diagnosis of uncomplicated dementia who were
administered Ginkgo for a year, a further positive outcome was claimed. In this study,
patients were tested using ADAS-cog, GERRI and CGIC. It is suggested that whilst these
different outcomes are compatible with (but do not affirm) a clinical benefit resulting from
the use of Ginkgo, the application of a more objective system of assessment would be able
to provide firm proof. It is proposed, therefore, that an objective, computer-based testing
system for assessment of clinical improvement in volunteers and patients administered
Ginkgo (such as CANTAB) would provide the convincing evidence currently being sought
by patients, carers, physicians, legislators and the pharmaceutical industry.

Title
The effects of acute doses of standardized Ginkgo biloba extract on memory and
psychomotor performance in volunteers.
Author
Rigney U; Kimber S; Hindmarch I
Source
Phytother Res, 1999 Aug, 13:5, 408-15
Abstract
This study investigated the effects of acute doses of Ginkgo biloba extract (GBE) on
memory and psychomotor performance in a randomized, double-blind and placebo
controlled 5-way cross-over design. Thirty-one volunteers aged 30-59 years received GBE
150 mg (50 mg t. d.s), GBE 300 mg (100 mg t.d.s.), GBE 120 mg mane and GBE 240
mg mane and placebo for 2 days. Following baseline measures, the medication was
administered at 0900 h for the single doses and at 0900, 1500 and 2100 h for the multiple
doses. The psychometric test battery was administered pre-dose (0830 h) and then at
frequent intervals until 11 h post dose. The results confirm that the effects of GBE extract
on aspects of cognition in asymptomatic volunteers are more pronounced for memory,
particularly working memory. They also show that these effects may be dose dependent
though not in a linear dose related manner, and that GBE 120 mg produces the most evident
effects of the doses examined. Additionally, the results suggest that the cognitive enhancing
effects of GBE are more likely to be apparent in individuals aged 50-59 years. Copyright
1999 John Wiley & Sons, Ltd.

Title
Protective effects of Ginkgo biloba extract against lysophosphatidylcholine-induced vascular
endothelial cell damage.
Author
Chen JX; Chen WZ; Huang HL; Chen LX; Xie ZZ; Zhu BY
Source
Chung Kuo Yao Li Hsueh Pao, 1998 Jul, 19:4, 359-63
Abstract
AIM: To study the protective effects of Ginkgo biloba extract (GbE) against endothelial cell
damage induced by lysophosphatidylcholine (LPC). METHODS: The vasorelaxation
response to acetylcholine (ACh) were investigated in the isolated rabbit thoracic aorta. Lipid
peroxidation products were determined by measuring thiobarbituric acid reactive substance.
RESULTS: GbE attenuated the inhibition of vasorelaxation response to ACh and prevented
the LPC-induced increase of malondialdehyde (MDA) content both in thoracic aortae. GbE
prevented the leakage of LDH and the increase of MDA content in cultured endothelial cells
in a concentration-dependent manner. GbE also markedly increased epoprostenol level in
cultured endothelial cells treated with LPC. CONCLUSION: GbE protected endothelial cells
against LPC-induced damage due to reduction in lipid peroxidation and facilitation of
synthesis and/or release of epoprostenol.

Title
The pharmacological effects of ginkgo biloba, a plant extract, on the brain of dementia
patients in comparison with tacrine.
Author
Itil TM; Eralp E; Ahmed I; Kunitz A; Itil KZ
Source
Psychopharmacol Bull, 1998, 34:3, 391-7
Abstract
In 1994, a standardized dry extract of Ginkgo biloba leaves (SeGb), has been approved by
German health Authorities for the treatment of primary degenerative dementia and vascular
dementia. More than 24 different brands of Ginkgo biloba extract are sold in the United
States. Tacrine, also known as tetrahydroaminoacrine (THA), and donepezil are currently
the only drugs approved in the United States for the treatment of Alzheimer's disease.
Previous studies demonstrated that SeGb and tacrine induce significant pharmacological
effects on the brains of young, healthy human males, as determined by bioelectrical activity
measurements obtained using the quantitative pharmaco-electroencephalogram (QPEEG)
method. The type of central nervous system (CNS) effects we have seen on
computer-analyzed EEGs (CEEGs) after administration of tacrine or EGb suggests both
are "cognitive activators" which are, as a class of products, characterized by a (prepost)
relative increase of 7.5 to 13 Hz ("alpha") and decrease of 1.3 to 7.5 Hz ("delta" and "theta")
activity. To determine whether EGb or tacrine had noticeable pharmacological effects on
elderly subjects diagnosed with possible or probable Alzheimer's, the present open,
uncontrolled trial was conducted. Data from 18 subjects (11 males, 7 females) at an average
age of 67.4 years with light to moderate dementia (Mini Mental mean score = 23.7, ranges:
15-29 [Geriatric Depression Scale mean scores = 3.7; range: 3.2-5.4]) were analyzed for
this presentation. Each subject was randomly administered a single oral "Test-Dose" of
either 40 mg of tacrine or 240 mg of EGb2 in two separate sessions within 3- to 7-day
intervals. Before drug administration and at 1- and 3-hour intervals after drug
administration, CEEGs were recorded for a minimum of 10 minutes. The CEEGs were
analyzed using Period Analysis programs we developed for QPEEG. The results indicated
that both EGb and, to a lesser degree, tacrine induced pharmacological effects, as established
by QPEEG measurements, in the CNS similar to those previously established in healthy,
young subjects. The type of CNS effects produced by EGb (as established by HZI's CEEG
psychotropic drug database) in elderly dementia patients were similar to those induced by
tacrine responders as well as those seen after the administration of other "cognitive
activators" (pramiracetam, vinpocetine, BMY-21502, suloctidil, and lisuride) and
anti-dementia drugs approved in the United States or Europe (tacrine, donepezil,
nimodipine, piracetam, and oxiracetam) from our database. The results also showed that
240 mg of EGb has typical cognitive activator CEEG profiles (responders) in more subjects
(8 of 18) than 40 mg tacrine (3 of 18 subjects). Because of the small sample size, we could
not test the hypothesis that subjects who showed cognitive activator-type pharmacological
response to the first Test-Dose of EGb or tacrine also exhibit more therapeutic effects
(compared to nonresponders) when drugs are administered chronically.

Title
Bioavailability of ginkgolides and bilobalide from extracts of ginkgo biloba using GC/MS
[letter]
Author
Biber A; Koch E
Source
Planta Med, 1999 Mar, 65:2, 192-3
Abstract
The bioavailability of ginkgolides A, B and bilobalide was studied in rats after single oral
administration of 30, 55 and 100 mg/kg Ginkgo extract EGb 761. The plasma levels of the
terpene lactones were measured by a specific GC/MS method. The pharmacokinetics of the
mentioned substances were found to be dose-linear. For the lowest dose maximum
concentrations were 68, 40 and 159 ng/ml and half-lives 1.7, 2.0 and 2.2 h for ginkgolide A,
B and bilobalide, respectively. Clearance values ranged from 24.2 to 37.6 ml/min/kg.

Title
Ginkgo biloba L.: history, current status, and future prospects [published erratum appears in
J Altern Complement Med 1997 Summer;3(2):205]
Author
Pang Z; Pan F; He S
Source
J Altern Complement Med, 1996 Fal, 2:3, 359-63
Abstract
In this paper, we describe the status of the exploration and use of the Ginkgo biloba leaves
in China. We emphasize the need for careful studies of the intra-specific genetic diversity of
Ginkgo biloba since genetic variation within this species may result in significant differences
between the chemical and pharmacological properties of the different sub-species. It is
therefore imperative that we catalog the intraspecific diversity of Ginkgo biloba L., and we
stress that it is important to conserve this diversity since different subspecies may have
different pharmacochemical properties resulting in differential medical usages.
Language of Publication
English
Unique Identifier
98051853