Efficacy Of Ginkgo Biloba Extract Research Articles

Research on bitter taste and efficacy of Ginkgo biloba extract based on UPLC-Q-TOF-MS~E integrated with molecular docking

Based on high performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry(UPLC-Q-TOF-MS~E) and molecular docking technique, bitter compounds of Ginkgo biloba extract(GBE) were characterized, and their relationship with bitter efficacy was investigated. Firstly, UPLC-Q-TOF-MS~E was used for qualitative analysis of GBE components, and 60 chemical components were identified. These chemical components were molecular-docked with bitter receptors, and 26 bitter substances were selected, mainly flavonoids. Secondly, sensory and electronic tongue bitterness evaluation techniques were used to verify that total flavones of GBE were the main bitter substances, which was consistent with the molecular docking results. Finally, network pharmacology was used to predict and analyze bitter substances. The relationship between the target of bitter substance and bitter effect was explored. The key targets of bitter substances are CYP2B6, ALOX15, and PTGS2, etc., and bitter substances may exert a bitter efficacy by ac-ting on related disease targets, indicating that bitter substances of GBE are the material basis of the bitter effect. In summary, the study indicated that the molecular docking technique had a guiding effect on the screening of bitter substances in traditianal Chinese medicine(TCM), and bitter substances of GBE had a bitter efficacy. It provides ideas and references for the study of the "taste-efficacy relationship" of TCM in the future.

Evaluating the Effectiveness of Ginkgo Biloba Extract in Alleviating Dizziness and Improving Nutritional Status in Cerebral Arteriosclerosis Patients

In this study, we aimed to evaluate the therapeutic efficacy of Ginkgo biloba extract in ameliorating dizziness symptoms and enhancing nutritional status in patients diagnosed with cerebral arteriosclerosis. A total of 170 patients suffering from cerebral arteriosclerosis were selected and divided randomly into two groups: a control group receiving conventional treatment and an experimental group receiving standard treatment plus Ginkgo biloba extract. A comparative analysis revealed that the experimental group demonstrated significant improvement in neurological function and mobility post-treatment, exhibited reduced dizziness symptoms and improved hemodynamics in the vertebral and basilar arteries compared with the control group (P < 0.05). The experimental group exhibited a significantly better nutritional status post-treatment compared with the control group (P < 0.05). To further elucidate the underlying mechanisms of Ginkgo biloba extract’s effects on cerebral arteriosclerosis, a cerebral arteriosclerosis rat model was developed. The results indicated that Ginkgo biloba extract intervention mitigated inflammation and oxidative stress in the brain tissues of rats with cerebral arteriosclerosis, leading to reduced pathological damage. These findings suggest that Ginkgo biloba extract has the potential to relieve cerebral arteriosclerosis-related dizziness and improve nutritional status in patients, offering a promising novel therapeutic modality for the clinical management of cerebral arteriosclerosis.

Evaluation of clinical efficacy of Ginkgo biloba extract in the treatment of knee osteoarthritis: a randomized clinical trial

Background: Osteoarthritis (OA) is a degenerative joint disease characterized by deteriorating articular cartilage. Most patients may not get enough control of symptoms in spite of the availability of various treatment options. Because of the synergistic impact of flavonoids and ginkgolides, Ginkgo biloba (GB) has been shown to possess antioxidant and anti-inflammatory properties besides its generally safe profile. This study aims to assess the efficacy and safety of the Ginkgo biloba extract (GBE) in patient with Knee OA . Methods: This is a randomized double blinded clinical trial conducted in a private orthopaedic clinic in Al-Najaf Government-Iraq between 1st November 2021 to 1st June 2022. Patients were randomized into two groups; Group A administered the standard treatment (diclofenac capsule 100 milligram sustained released with paracetamol 1 gram twice daily) with GBE capsule 120 milligram twice daily, while Group B administered the standard treatment with placebo (starch) capsule only. The Knee injury and Osteoarthritis Outcome Score (KOOS) was performed to assess the efficacy of the GBE in patient with Knee OA for eight weeks.Results: 60 patients (Group A: mean age 54.2±8.6, male 24.24%, female 75.76%; Group B: mean age 58.0±8.4, male 22.22%, female 77.78%) successfully completed the eight weeks follow up. Pain, symptoms, sport, activity of daily living (ADL) scores showed significant improvement in Group A from the first two weeks after treatment with GB in comparison with group B. however, scores of quality of life (QOL) were not significantly improved in two group comparison at each assessment week. Only 10 patients (group A:8, group B:2) reported gastrointestinal adverse effects during the study which were all mild. Conclusions: GB may provide additional beneficial health effects to patients with knee OA based on KOOS scores when add to the standard treatment regime. Registration: ClincialTrials.gov (NCT05398874, https://clinicaltrials.gov/ct2/show/NCT05398874).

Retracted: Efficacy of Ginkgo biloba Extract Combined with Hormones in the Treatment of Sudden Deafness and Its Effect on the Reactivity of Peripheral Blood T Cell Subsets.

[This retracts the article DOI: 10.1155/2022/2903808.].

Evaluation of clinical efficacy of Ginkgo biloba extract in the treatment of knee osteoarthritis: a randomized clinical trial

Background: Osteoarthritis (OA) is a degenerative joint disease characterized by deteriorating articular cartilage. Most patients may not get enough control of symptoms in spite of the availability of various treatment options. Because of the synergistic impact of flavonoids and ginkgolides, Ginkgo biloba (GB) has been shown to possess antioxidant and anti-inflammatory properties besides its generally safe profile. This study aims to assess the efficacy of the Ginkgo biloba extract (GBE) in patient with Knee OA. Methods: This is a randomized double blinded clinical trial conducted in a private orthopaedic clinic in Al-Najaf Government-Iraq. Patients were randomized into two groups; Group A administered the standard treatment (diclofenac capsule 100 milligram sustained released with paracetamol 1 gram twice daily) with GBE 120 milligram twice daily, while Group B administered the standard treatment with placebo (starch) capsule only. The Knee injury and Osteoarthritis Outcome Score (KOOS) was performed to assess the efficacy of the GBE in patient with Knee OA for eight weeks. Results: 60 patients successfully completed the eight weeks follow up. Pain, symptoms, sport, activity of daily living (ADL) scores showed significant improvement in Group A from the first two weeks after treatment with GB in comparison with group B. however, scores of quality of life (QOL) were not significantly improved in two group comparison at each assessment week. Only 10 patients reported gastrointestinal adverse effects during the study which were all mild. Conclusions: GB may provide additional beneficial health effects to patients with knee OA based on KOOS scores when add to the standard treatment regime. Registration: ClincialTrials.gov (NCT05398874, https://clinicaltrials.gov/ct2/show/NCT05398874).

Efficacy of Ginkgo biloba Extract Combined with Hormones in the Treatment of Sudden Deafness and Its Effect on the Reactivity of Peripheral Blood T Cell Subsets.

This work was aimed at exploring the efficacy of Ginkgo biloba extract combined with hormones in the treatment of sudden deafness and the influence on the reactivity of peripheral blood T cell subsets (PBTCSs). In this work, 64 patients with sudden deafness who were treated in The First Affiliated Hospital of Hunan University of Traditional Chinese Medicine from August 2019 to August 2022 were selected as the research objects. The patients were randomly divided into a hormone group (treatment with prednisone acetate, n = 34) and a combination group (treatment with Ginkgo-Damole combined with prednisone acetate, n = 30). After the two groups of patients were treated in different ways, their efficacy, symptom improvement, changes in blood rheology, and PBTCSs were compared. The total effective rates (TERs) of the hormone group and the combination group were 76.32% and 95.73%, respectively (P < 0.05). The fibrinogen contents of the patients in the combination group were obviously lower than those in the hormone group after 5 d, 7 d, and 10 d of treatment (P < 0.05). The high blood viscosity (HBV) values of patients in the combination group at 5 d, 7 d, and 10 d after treatment were greatly lower than those in the hormone group (P < 0.05). The low blood viscosity (LBV) values after 3 d, 7 d, and 10 d of treatment in the combined group were much lower in contrast to those in the hormone group (P < 0.05). The CD3+, CD4+, and CD4+/CD8+ in peripheral blood in the combination group were sharply higher while the CD8+ in the combined group was lower in contrast to the hormone group (P < 0.05). There was no visible difference in the incidence of adverse reactions between the two groups of patients after treatment (P > 0.05). In conclusion, the combined application of Ginkgo biloba extract and hormones could effectively improve the abnormal hemorheological indexes of patients with sudden deafness and effectively relieve the imbalance of PBTCSs, which was safe.

A preclinical randomized controlled study of ischemia treated with Ginkgo biloba extracts: Are complex components beneficial for treating acute stroke?

The rigorous design of preclinical experimental studies of candidate neuroprotectants for the treatment of acute ischemic stroke is crucial for the success of subsequent randomized clinical trials. The efficacy of Ginkgo biloba extracts (GBEs) in complex mixtures for the treatment of acute ischemic stroke remains unclear. In this preclinical randomized controlled trail (pRCT), the effects of a novel (n)GBE containing pinitol versus traditional (t)GBE without pinitol were evaluated on the mouse models of acute transient and permanent stroke, separately. The sample size, an important aspect of study design, was calculated based on our experimental data. Mice with ischemia that were induced by transient middle cerebral artery occlusion (tMCAO) or permanent distal middle cerebral artery occlusion (pdMCAO), were treated with vehicle, nGBE, tGBE, or pinitol alone by tail-vein injection. Our results showed that nGBE significantly reduced infarct size in mice with tMCAO compared with vehicle-treated control mice. Both nGBE and tGBE significantly reduced infarct size in mice with pdMCAO compared with the vehicle-treated controls. None of the three treatments rescued weight loss or prevented the neurological deficits in either the tMCAO- or pdMCAO-model mice. These findings suggest that nGBE, which includes all of the components of tGBE and pinitol, is neuroprotective in two ischemic stroke models. Additional studies of complex GBE mixtures for stroke treatment compared to single component medications are undergoing evaluation.

Neuroprotective and neurotrophic efficacy of Ginkgo biloba extracts against 3-nitropropionic acid-induced oxidative stress in a rat model of Huntington's disease

Huntington's disease (HD) is a progressive neurodegenerative disorder. Ginkgo biloba extracts (GBE), a phytoestrogen, has been widely used for treating coronary heart disease and neurological disease. The present study examined the potential neuroprotective and neurotrophic efficacy of GBE against 3-nitropropionic acid (3-NP)-induced oxidative stress in a rat model of HD and explored the mechanisms of action. 60 Male SD rats were pretreated with GBE (25 and 50 mg/kg b.w.) orally prior to the intraperitoneally (i.p.) administration of 3-NP (12 mg/kg b.w.) for 15 days. Nimodipine (12 mg/kg, po) was used as positive control drugs. The body weight, grip strength and behavior were monitored within 5th, 10th and 15th day after 3-NP treatment. Then the animals were sacrificed, neuronal damage in striatum was estimated using Nissl staining. Memory (Morris water maze), antioxidants enzymes, acetylcholinesterase (AChE) activity, cycloxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) expression were analyzed in rat model of HD. Present results shown that administration of 3-NP resulted in a marked reduction in the body weight, memory, grip strength locomotion activity and significantly increased oxidative stress, AChE activity, COX-2 and inducible iNOS expression. GBE (25 and 50 mg/kg) treated animals exhibited a significant improvement in behavioural, biochemical, histological alterations and oxidative stress parameters in comparison to only 3-NP treated animals. Present results shown dose-dependently improved 3-NP-induced behavioral, biochemical, and enzymatic changes. Similar effects were obtained with the positive control drugs nimodipine. Study suggests neuroprotective, neurotrophic and memory enhancing effects for GBE in a rat model of HD.

Efficacy of ginkgo biloba extract as augmentation of venlafaxine in treating post-stroke depression.

BackgroundPost-stroke depression (PSD) is one of the most common psychiatric diseases afflicting stroke survivors. This study was conducted to assess the efficacy of ginkgo biloba extract as augmentation of venlafaxine in treating PSD.MethodsThe included PSD patients were randomly assigned into the experiment group (receiving ginkgo biloba extract plus venlafaxine) and control group (receiving venlafaxine alone). The treatment was continued for eight weeks. The Hamilton Depression Rating Scale (HDRS) and the Self-rating Depression Scale (SDS) were used to assess the depressive symptoms. The National Institutes of Health Stroke Scale (NIHSS) was used to assess the neurological defect, and the Activities of Daily Living (ADL) was used to assess recovery of abilities of patients after stroke. Meanwhile, the levels of serum 5-hydroxytryptamine (5-HT) and brain-derived neurotrophic factor (BDNF) were measured before and after treatment. The dose of venlafaxine used and adverse events were also recorded.ResultsEach group had 40 PSD patients. After treatment, the depressive symptoms, neurological defect and living function were significantly improved in both groups. But the patients receiving ginkgo biloba extract plus venlafaxine had the significantly lower average HDRS score (p=0.0008), SDS score (p<0.00001), NIHSS score (p=0.00001), and higher average ADL score (p=0.0005). Meanwhile, compared to the control group, patients in the experiment group had the significantly higher 5-HT (p<0.00001) level and BDNF level (p<0.00001), needed lower dose of venlafaxine (p=0.007), and experienced fewer adverse events.ConclusionThese results demonstrated that the ginkgo biloba extract was a good augmentation of venlafaxine in treating PSD and should be further investigated.

Effects of Ginkgo biloba extract on brain oxidative condition after cisplatin exposure

The purpose of this study was to evaluate the efficacy of Ginkgo biloba extract (EGb 761) on oxidative events of brain in cisplatin-administrated rats. Rats were divided into four experimental groups: 1) control (n=6); 2) cisplatin (8 mg/kg, intraperitoneally one dose, n=6); 3) EGb 761 (100 mg/kg intraperitoneally for 15 days, n=6); and 4) cisplatin + EGb 761 (n=6). After drug administration, rats were sacrificed and brain tissues were removed. Nitric oxide (NO), malondialdehyde (MDA) and glutathione (GSH) levels were evaluated in brain tissues. Single dose cisplatin administration significantly increased NO and GSH levels, but decreased MDA levels in brain tissue samples. EGb 761 treatment reversed the effects of cisplatin on NO and GSH levels, but did not affect the decreased MDA levels. Results of the study indicate that oxidative stress can be an important pathogenetic mechanism of cisplatin-induced neurotoxicity. EGb 761, an standardized extract of G. biloba leaves that has antioxidant properties, may improve the oxidative stress-related neurological side effects of cisplatin.

EGb761 Ameliorates Neuropathic Pain by Scavenging Reactive Oxygen Species

Background: Neuropathic pain is a well-known type of chronic pain caused by damage to the nervous system. Until recently, researchers have found that increased generation of reactive oxygen species (ROS) contributes to the development of exaggerated pain hypersensitivity during neuropathic pain. Methods: In this study, we investigated the antinociceptive efficacy of Ginkgo biloba extract (EGb761) in chronic constriction injury (CCI) model of neuropathic pain of rats. To explore the underlying mechanisms, the effects of EGb761 on the excitability of dorsal root ganglion (DRG) neurons and activation of JNK in DRG were explored. Results: We showed that systemic administration of EGb761 inhibited the behavioral responses of neuropathic pain and found that EGb761 treatment could inhibit the H₂O₂-induced depolarization in the acutely dissociated DRG neurons. In addition, we found that EGb761 treatment could inhibit the expression of p-JNK in DRG. Conclusion: Taken together, our results suggest that administration of EGb761 can ameliorate neuropathic pain, and further indicate that JNK, which is activated by both exogenous and endogenous ROS, might be the mechanism underlying the effects of EGb761 on CCI neuropathic pain.

Die Rolle der externen Validität bei der Beurteilung klinischer Studien zur Demenzbehandlung mit Ginkgo-biloba-Extrakten

Ginkgo bilobaextracts have been applied in the treatment of dementia of vascular origin and Alzheimer disease for a long time. However, in the most elaborated systematic review to date, Birks and colleagues drew quite a moderate conclusion in spite of the overall positive results. The reason for such a moderate interpretation often lies in the preference of internal validity such as randomisation and blinding, sometimes at the expense of external validity (conditions of everyday practice). Because of this, we analysed the clinical trials evaluated by Birks et al. in the light of the following questions: 1) To what extent are criteria of external validity considered? 2) Does the additional evaluation of external validity lead to differences in the estimation of efficacy? 3) What are the results of our analysis in regard to the efficacy of ginkgo biloba extract? The selection of the clinical trials was based upon those included in the review carried out by Birks et al. (2002). The criteria for evaluating external validity were developed by consulting physicians specialised in geriatrics, experts in herbal pharmaceutics and affected/ related individuals (patients and relatives). We analysed 34 placebo-controlled clinical trials with a total of 37 comparisons. 21 trials showed significant results in favour of the ginkgo application in more than 50% of investigated outcome parameters, eight were significant for less than 50% of the parameters, four showed a trend in favour of ginkgo, and only two studies (with 4 comparisons) found no advantage for ginkgo. One of these negative studies used daily doses far below the usual dose range [corrected] We found no evidence for publication bias. None of the studies considered all criteria of external validity. Out of the seven studies with relatively high external validity and good overall quality, five showed a significant result in more than 50% of parameters, two in < or = 50%. Severe adverse effects were not mentioned in the studies. 1) In the clinical studies analysed external validity was taken into account only moderately, especially with respect to additional non-pharmaceutical interventions and selection of participants. 2) The evaluation according to external validity led to a different selection of studies that were used for estimation of the ginkgo efficacy without effects on the overall result. 3) Sufficient evidence of the efficacy of ginkgo bilobaextracts in the treatment of dementia of vascular origin and Alzheimer disease is provided in spite of methodological limitations. Further studies should focus on effectiveness, ginkgo-sensitive subgroups, more individualised therapeutic goals and corresponding outcome measurements.

A randomized placebo-controlled trial of Ginkgo biloba for the prevention of cognitive decline

To assess the feasibility, safety, and efficacy of Ginkgo biloba extract (GBE) on delaying the progression to cognitive impairment in normal elderly aged 85 and older. Randomized, placebo-controlled, double-blind, 42-month pilot study with 118 cognitively intact subjects randomized to standardized GBE or placebo. Kaplan-Meier estimation, Cox proportional hazard, and random-effects models were used to compare the risk of progression from Clinical Dementia Rating (CDR) = 0 to CDR = 0.5 and decline in episodic memory function between GBE and placebo groups. In the intention-to-treat analysis, there was no reduced risk of progression to CDR = 0.5 (log-rank test, p = 0.06) among the GBE group. There was no less of a decline in memory function among the GBE group (p = 0.05). In the secondary analysis, where we controlled the medication adherence level, the GBE group had a lower risk of progression from CDR = 0 to CDR = 0.5 (HR = 0.33, p = 0.02), and a smaller decline in memory scores (p = 0.04). There were more ischemic strokes and TIAs in the GBE group (p = 0.01). In unadjusted analyses, Ginkgo biloba extract (GBE) neither altered the risk of progression from normal to Clinical Dementia Rating (CDR) = 0.5, nor protected against a decline in memory function. Secondary analysis taking into account medication adherence showed a protective effect of GBE on the progression to CDR = 0.5 and memory decline. Results of larger prevention trials taking into account medication adherence may clarify the effectiveness of GBE. More stroke and TIA cases observed among the GBE group requires further study to confirm.

Providing complementary and alternative medicine (CAM) to drug users: a pilot observational study

PURPOSE: The optimal treatment of intermittent claudication has not yet been identified. Ginkgo biloba extract has been reported to have beneficial effects. We performed a meta-analysis of the efficacy of Ginkgo biloba extract for intermittent claudication based on the results of randomized, placebo-controlled, double-blind trials.METHODS: Literature searches of Medline, Embase, Biosis, AMED, CISCOM, and the Cochrane Library were performed to identify studies on the topic. Manufacturers of commercial Ginkgo biloba products and authors of original publications and reviews were contacted to provide additional information. No language restrictions were imposed.RESULTS: Eight randomized, placebo-controlled, double-blind trials were included. Meta-analysis found a significant difference in the increase in pain-free walking distance in favor of Ginkgo biloba (weighted mean difference: 34 meters, 95% confidence interval [CI]: 26 to 43 meters). In studies using similar methodological features (ergometer speed: 3 km/h, inclination: 12%) this difference was 33 meters in favor of Ginkgo biloba (95% CI: 22 to 43 meters). Adverse effects were rare, mild, and transient.CONCLUSIONS: These results suggest that Ginkgo biloba extract is superior to placebo in the symptomatic treatment of intermittent claudication. However, the size of the overall treatment effect is modest and of uncertain clinical relevance.

Ginkgo Biloba extract for the treatment of intermittent claudication: a meta-analysis of randomized trials

PURPOSE: The optimal treatment of intermittent claudication has not yet been identified. Ginkgo biloba extract has been reported to have beneficial effects. We performed a meta-analysis of the efficacy of Ginkgo biloba extract for intermittent claudication based on the results of randomized, placebo-controlled, double-blind trials. METHODS: Literature searches of Medline, Embase, Biosis, AMED, CISCOM, and the Cochrane Library were performed to identify studies on the topic. Manufacturers of commercial Ginkgo biloba products and authors of original publications and reviews were contacted to provide additional information. No language restrictions were imposed. RESULTS: Eight randomized, placebo-controlled, double-blind trials were included. Meta-analysis found a significant difference in the increase in pain-free walking distance in favor of Ginkgo biloba (weighted mean difference: 34 meters, 95% confidence interval [CI]: 26 to 43 meters). In studies using similar methodological features (ergometer speed: 3 km/h, inclination: 12%) this difference was 33 meters in favor of Ginkgo biloba (95% CI: 22 to 43 meters). Adverse effects were rare, mild, and transient. CONCLUSIONS: These results suggest that Ginkgo biloba extract is superior to placebo in the symptomatic treatment of intermittent claudication. However, the size of the overall treatment effect is modest and of uncertain clinical relevance.

Medicinal plants and Alzheimer's disease: Integrating ethnobotanical and contemporary scientific evidence.

The use of complementary medicines such as plant extracts in dementia therapy, varies according to the different cultural traditions. In orthodox Western medicine, contrasting with that in China and the Far East for example, pharmacological properties of traditional cognitive or memory enhancing plants have not been widely investigated in the context of current models of Alzheimer's disease. An exception is Ginkgo biloba in which the ginkgolides have antioxidant, neuroprotective, and cholinergic activities relevant to Alzheimer's disease mechanisms. The therapeutic efficacy of Ginkgo biloba extracts in Alzheimer's disease in placebo-controlled clinical trials is reportedly similar to currently prescribed drugs such as tacrine or donepezil and, importantly, undesirable side effects of Ginkgo biloba are minimal. Old European reference books (eg, medical herbals) document a variety of other plants such as Salvia officinalis (sage) and Melissa officinalis (balm) with memory improving properties, and cholinergic activities have recently been identified in extracts of these plants. Precedents for modern discovery of clinically relevant pharmacological activities in plants with long-established medicinal use include, for example, the interaction of alkaloid opioids in Papaver somniferum (Opium poppy) with endogenous opiate receptors in the brain. With recent major advances in understanding the neurobiology of Alzheimer's disease, and as yet limited efficacy of so-called rationally designed therapies, it may be timely to re-explore historical archives for new directions in drug development. This article considers not only the value of an integrative traditional and modern scientific approach to developing new treatments for dementia, but also in the understanding of disease mechanisms. Long before the current biologically based hypothesis of cholinergic derangement in Alzheimer's disease emerged, plants now known to contain cholinergic antagonists were recorded for their amnesic and dementia-inducing properties.

자각성 이 명 환자에서 Ginkgo biloba extracts (Ginexin-F)의 제 3상 임상 효과

자각성 이 명 환자에서 Ginkgo biloba extracts (Ginexin-F)의 제 3상 임상 효과

Ginkgo biloba for cerebral insufficiency.

1. By means of a critical review we tried to establish whether there is evidence from controlled trials in humans on the efficacy of Ginkgo biloba extracts in cerebral insufficiency. 2. The methodological quality of 40 trials on Ginkgo and cerebral insufficiency was assessed using a list of predefined criteria of good methodology, and the outcome of the trials was interpreted in relation to their quality. A comparison of the quality was made with trials of co-dergocrine, which is registered for the same indication. 3. There were eight well performed trials out of a total of 40. Shortcomings were limited numbers of patients included, and incomplete description of randomization procedures, patient characteristics, effect measurement and data presentation. In no trial was double-blindness checked. Virtually all trials reported positive results, in most trials the dosage was 120 mg Ginkgo extract a day, given for at least 4-6 weeks. For the best trials, there were no marked differences in the quality of the evidence of the efficacy of Ginkgo in cerebral insufficiency compared with co-dergocrine. The results of the review may be complicated by a combination of publication bias and other biases, because there were no negative results reported in many trials of low methodological quality. 4. Positive results have been reported for Ginkgo biloba extracts in the treatment of cerebral insufficiency. The clinical evidence is similar to that of a registered product which is prescribed for the same indication. However, further studies should be conducted for a more detailed assessment of the efficacy.