Can ginkgo biloba dust off mental cobwebs?
Explore the source record for details and available documents.
Double-Blind Method↗
SEARCH · PubMed Health
Results for “Ginkgo Extract”
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Herbs commonly used by women: an evidence-based review.
OBJECTIVE: To review the evidence of herbs commonly used by women. DATA SOURCES: Articles were located by searching Medline, Cochrane Database of Systemic Reviews, and the Combined Health Information Database and by hand searching the reference lists of recent systematic reviews. The databases were searched in January 2000 and October 2000 by using the Latin and common name of each herb. METHODS OF STUDY SELECTION: Preference was given to randomized, placebo-controlled trials. When available, English language studies were reviewed. If not, data are presented from review articles that summarize the foreign study. RESULTS: Many women use herbal therapies. In the United States, herbs are considered dietary supplements. The Food and Drug Administration (FDA) cannot remove them from the market unless they are proven unsafe. The herb industry plans to improve monitoring. Many prospective randomized controlled trials are being funded. Gingko biloba seems to slow the progression of dementia but increases the risk of bleeding. St John's Wort is efficacious for treating mild to moderate depression but has many drug interactions. Ginseng seems to improve well being in perimenopausal women, but it is often impure and has side effects and drug interactions. Garlic slightly lowers blood pressure and lipids. Echinacea slightly decreases the duration of colds but does not prevent them. Valerian is beneficial for insomnia, but there is no long-term safety data. Black cohosh may help the symptoms of perimenopause, and chasteberry may improve premenstrual syndrome. More study is needed on both herbs. CONCLUSION: Some herbs are medically useful, but the American public would benefit from increased regulation. Manufacturers should be able to ensure that herbs contain pure ingredients. Side effects and drug interactions should be listed. Well-designed studies are being conducted. The results will be helpful to physicians and patients when the clinical evidence becomes available.
Cimicifuga↗
Interactions of warfarin with garlic, ginger, ginkgo, or ginseng: nature of the evidence.
OBJECTIVE: To review and characterize the evidence describing potential interactions between warfarin and garlic, ginger, ginkgo, or ginseng. DATA SOURCES: Searches of MEDLINE (1966-1999), other bibliographic databases, several abstracting services, and tertiary references were conducted. STUDY SELECTION AND DATA EXTRACTION: Articles were examined by each author, and additional citations were obtained from the references of these articles. Preference was given to Englishlanguage articles of human studies. DATA SYNTHESIS: Evidence is lacking for an interaction of warfarin wth galic or ginger. One case report associates ginseng use with decreased warfarin-maintained anticoagulation effect. Another case report links concomitant use of ginkgo and warfarin with the development of intracerebral hemorrhage. Hemorrhage and tendencies were noted in four cases with ginkgo use and in three cases with garlic; in none of these cases were patients receiving warfarin. CONCLUSIONS: The true risks of these interactions and effects are difficult to characterize due to the limited number and nature of existing reports.
Anticoagulants↗
Lack of herbal supplement characterization in published randomized controlled trials.
PURPOSE: Herbal supplements in the United States and abroad have poor quality control and high content variability. We assessed the extent to which recently published randomized controlled trials of herbal supplements characterized and verified the content of the supplement under study. METHODS: We identified all MEDLINE-indexed English language randomized controlled trials evaluating single-herb preparations of echinacea, garlic, ginkgo, saw palmetto, or St. John's wort that were published between January 1, 2000, and February 9, 2004. From each article we extracted information characterizing the herbal supplement studied. RESULTS: Of 81 randomized controlled trials meeting inclusion criteria, 12 (15%) reported performing tests to quantify actual contents, and 3 (4%) provided adequate data to compare actual with expected content values of at least one chemical constituent. In those 3 studies, actual content varied between 80% and 113% of expected values. Studies of higher overall quality (Jadad score > or =3) performed testing somewhat less frequently (5/54; 9%) than those with lower Jadad scores (7/27; 26%) (P = .09). CONCLUSION: Documented characterization of herbal supplements in published randomized controlled trials is inadequate. Investigators may be unaware of the extent to which herbal quality-control issues may detract from the value of otherwise well-designed clinical trials. The scientific and clinical utility of future herbal randomized controlled trials would be enhanced if authors provided evidence that the herbal products studied were of high quality.
Drug Contamination↗
DNA polymorphism in the living fossil Ginkgo biloba from the eastern United States.
Random amplified polymorphic DNA (RAPD) analysis is a valuable tool in studying inter- and intra-specific genetic variations, patterns of gene expression, and for the identification of specific genes using nearly isogenic variants. Here we used RAPD analysis to study the genetic variation in Ginkgo biloba grown in the eastern United States. Our results support the evidence that Southern blot hybridization of RAPD using probes made from cloned DNA fragments allows a more accurate analysis of the RAPD pattern than dye-stained gels or Southern blot hybridization of RAPD blots using probes made from purified PCR products. Using these techniques, we observed a high degree of relatedness among plants grown in certain localities although significant genetic variation may exist in the species, and could be a possible explanation for the observed variations in the efficacy of medications derived from G. biloba extract.
District of Columbia↗
[Ginkgo biloba--analysis and dosage forms].
Explore the source record for details and available documents.
Chromatography, High Pressure Liquid↗
Screening of Brazilian plant extracts for antioxidant activity by the use of DPPH free radical method.
Brazilian plant extracts belonging to 16 species of 5 different families (71 extracts) were tested against the stable DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) free-radical. The ability to scavenge DPPH radical was measured in these experiments by the discoloration of the solution. Ginkgo biloba and rutin, commonly used as antioxidants for medical purposes, were used as standards. Based on our results, we can say that as a general rule the ethanol extracts of plants belonging to the Verbenaceae family showed lower EC(50) values than the other plant extracts. Among the partitions, the more polar ones (ethyl acetate and n-butanol) are those that generally have higher antioxidant activity (AA).
Antioxidants↗
Studies on natural products.
Explore the source record for details and available documents.
Altitude Sickness↗
Triple-blind, placebo-controlled trial of Ginkgo biloba in sexual dysfunction due to antidepressant drugs.
A triple-blind (investigator, patient, statistician), randomized, placebo-controlled, trial of Ginkgo biloba 240 mg daily was carried out. Following a 1-week control, it was given to 24 patients with sexual impairment due to antidepressant drugs. Efficacy analysis was carried out on eight males and five females on placebo and six males and five females on Ginkgo, completing the full 12 weeks of treatment. Not included were three subjects who dropped out after 6 weeks. A validated, sex (gender)-orientated questionnaire was recorded at - 1, 0, 1, 3, 6, 9 and 12 weeks, and a non-blind follow-up for a further 6-weeks on Ginkgo. Hamilton anxiety and depression ratings were made at 0, 6 and 12 weeks and simple global assessments of alertness and memory. There were some spectacular individual responses in both groups, but no statistically significant differences, and no differences in side-effects.
Adult↗
Effect of ginkgolides on beta-amyloid-suppressed acetylocholine release from rat hippocampal slices.
As Ginkgo has been shown to improve age-related memory de fi cits and beta-amyloid-related peptides have been suggested to play a signi fi cant role in memory degeneration in Alzheimer's disease, the present study was carried out to examine the effect of two major ginkgolides, A and B, on beta-amyloid peptide-modulated acetylcholine (ACh) release from hippocampal brain slices. Addition of beta-amyloid fragment(25-35) (0.01-1 micro M) in the superfusion medium suppressed the K(+)-evoked [(3)H]-ACh release from the rat hippocampal slices in a concentration-related manner; a 40% reduction in ACh out fl ow was observed with the highest amyloid concentration used (1 micro M). Inclusion of ginkgolide B (GKB, 0.01-10 micro M) caused a concentration-related reversion of the inhibitory effect elicited by the effective concentration of beta-amyloid (1 micro M). The reversal of the beta-amyloid-inhibited ACh release by GKB (1 micro M) was not blocked by tetrodotoxin (1 micro M) indicating a direct interaction of GKB on the cholinergic nerve terminals. In contrast, addition of the same concentration range of ginkgolide A (GKA, 0.01-10 micro M) had no effect on beta-amyloid-inhibited ACh release. These results suggest that GKB may elicit its anti-amnesic effect by minimizing the inhibitory effect of beta-amyloid peptides on cholinergic transmission.
Acetylcholine↗
Effects of Herbal vX on libido and sexual activity in premenopausal and postmenopausal women.
This study investigated the possibility of an alternative to chemical medication in the treatment of sexual dysfunction in healthy women. The efficacy of a unique herbal formulation of Muira puama and Ginkgo biloba (Herbal vX) was assessed in 202 healthy women complaining of low sex drive. Various aspects of their sex life were rated before and after 1 month of treatment. Responses to self-assessment questionnaires showed significantly higher average total scores from baseline in 65% of the sample after taking the supplement. Statistically significant improvements occurred in frequency of sexual desires, sexual intercourse, and sexual fantasies, as well as in satisfaction with sex life, intensity of sexual desires, excitement of fantasies, ability to reach orgasm, and intensity of orgasm. Reported compliance and tolerability were good. These initial findings support the strong anecdotal evidence for the benefits of Herbal vX on the female sex drive. A double-blind study is planned to further research these results.
Adult↗
Cytoprotection by Achyrocline satureioides (Lam) D.C. and some of its main flavonoids against oxidative stress.
Epidemiological studies indicate that dietary antioxidants can influence the incidence of neurodegenerative diseases. Among them flavonoids have been proposed to be effective cytoprotectors. Consequently, herbs with a high concentration of these compounds such as Achyrocline satureioides, Ginkgo biloba and Epilobium parviflorum are of special interest. In this context a comparative study of the cytoprotective capacity of infusions from the three plants against an oxidative insult was performed. Hence, the cytoprotective activity of each infusion against H2O2 injury to PC12 cells was tested and the antioxidant capacity was assessed by the ABTS*+ radical bleaching assay. Free and glycosylated flavonoids contained in the infusions were identified by HPLC and the cytoprotective effect of some of these individual flavonoids was tested. The analysis of the flavonoid content of the infusions revealed different profiles. Epilobium parviflorum infusion showed the highest antioxidant capacity but only Achyrocline satureioides infusion proved to be cytoprotective. Moreover, the free flavonoids quercetin and luteolin contained in this infusion were also cytoprotective. In conclusion, the free radical scavenger capacity did not correlate with the cytoprotective profile of the infusions. The special mixture of unglycosylated Achyrocline satureioides flavonoids could be a clue to explain the unique effect of this plant.
Achyrocline↗
The peri-operative implications of herbal medicines.
An increasing number of patients are taking herbal medicines such as echinacea, garlic, ginkgo biloba, ginseng, St John's Wort, valerian, ephedra, kava, grapefruit juice and ginger. Although these herbal medications are considered 'natural' products that may have some benefits, adverse effects such as increased bleeding tendencies and drug interactions are associated with their use. Surgeons and anaesthetists may be unaware of their patients' use of these medications because it is common for patients not to disclose their use of this form of medication, and both surgeons and anaesthetists often fail to enquire about their use. Anaesthetists and surgeons must be familiar with the effects of herbal medicines and should specifically enquire about the use of herbal medicines during pre-operative assessment. Currently available data suggest that all herbal medicines should be ceased 2 weeks before surgery.
Anesthesia↗
Inhibition of cGMP-phosphodiesterase-5 by biflavones of Ginkgo biloba.
Ginkgo biloba dimeric flavonoids (GBDF) were shown to inhibit cAMP phosphodiesterase activity and to promote vasorelaxation. In particular, amentoflavone exhibited endothelium-dependent relaxation of rat aorta rings via enhanced generation and/or increased biological activity of nitric oxide, leading to elevated cGMP levels. The aim of this study was to investigate whether GBDF were able to inhibit cGMP-specific phosphodiesterase-5 (PDE5) as well. Human recombinant PDE5A1 was prepared by expression of the full-length cDNA of PDE5A1 in COS-7 cells. The PDE activity was determined in the presence of biflavones at 0.1-100 microM. All biflavones inhibited PDE5A1 in a concentration-dependent fashion, ginkgetin being the most potent (IC50 = 0.59 microM). The ability to inhibit the enzyme followed this order: ginkgetin > bilobetin > sciadopitysin > amentoflavone > sequoiaflavone. These data suggest that GBDF could exert a vasodilating effect through a mechanism independent of NO release.
3',5'-Cyclic-GMP Phosphodiesterases↗
A review of plant-derived and herbal approaches to the treatment of sexual dysfunctions.
Despite the increasing availability of effective conventional medical treatments, plant-derived and herbal remedies continue to provide a popular alternative for men and women seeking to improve their sex life. Nevertheless, the efficacy of most herbal agents in treating sexual problems remains uncertain. Therapists and consumers alike would benefit from an increased understanding of commonly used herbal agents on the market, their purported or supported effects, and their potential side effects. To this end, we cataloged the major prosexual herbal agents currently sold in several representative health food stores. We also specify the sexual problem purportedly ameliorated by each herbal agent. Finally, we evaluate eight herbal agents commonly promoted for the treatment of sexual problems. This evaluation includes a review of the research supporting the use, efficacy, dose, adverse effects, contraindications, and possible mechanism of action of each. We conclude by commenting on the quality of current research, pointing out gaps in our knowledge, and noting the need for rigorous research and product control to adequately address questions regarding the efficacy of these agents.
Brassica↗
Gincosan (a combination of Ginkgo biloba and Panax ginseng): the effects on mood and cognition of 6 and 12 weeks' treatment in post-menopausal women.
As memory and concentration impairments are a frequent complaint in post-menopausal women, this well-defined population was selected to investigate the effect on mood and cognition of chronic treatment with Gincosan. In a double-blind placebo controlled study, post-menopausal women aged 51-66 were randomly assigned to 12 weeks' treatment with Gincosan (320mg/day), containing 120mg Ginkgo biloba, and 200mg Panax ginseng (n = 30), or matched placebo (n = 27). They were given measurements of mood, somatic anxiety, sleepiness, and menopausal symptoms and a battery of cognitive tests before treatment and after 6 and 12 weeks of treatment. There were no significant effects of Gincosan treatment on ratings of mood, bodily symptoms of somatic anxiety, menopausal symptoms, or sleepiness or on any of the cognitive measures of attention, memory or frontal lobe function. Thus, after chronic administration, Gincosan appeared to have no beneficial effects in post-menopausal women.
Affect↗
Mental status changes in an alcohol abuser taking valerian and gingko biloba.
Explore the source record for details and available documents.
Alcohol-Related Disorders↗
The inhibitory effects of herbal components on CYP2C9 and CYP3A4 catalytic activities in human liver microsomes.
Herbal medicines are widely consumed by patients in different clinical settings in the United States and all over the world. In this study, 7 herbal components ginsenosides Rb1, Rb2, Rc, and Rd (from ginseng quercetin) ginkgolides A and B (from ginkgo biloba) were investigated for their inhibitory effects on hepatic CYP2C9 and CYP3A4 catalytic activities in human liver microsomes. Tolbutamide 4-methylhydroxylation and testosterone 6beta-hydroxylation were used as index reactions of CYP2C9 or CYP3A4 catalytic activities, respectively. The metabolites of both reactions were measured by high-performance liquid chromatography and used as indicators of whether enzymes were inhibited or unaffected by these agents. Herbal components were studied at various concentrations (0.1, 1, 10, 100, 200 micromol/L). The herbal compounds investigated were capable of inhibiting CYP2C9 and CYP3A4 catalytic activities, but the potencies differed. Quercetin showed marked inhibitory effects on both tolbutamide 4-methylhydroxylation and testosterone 6beta-hydroxylation with IC(50) values of 35 and 38 micromol/L, respectively. Ginsenoside Rd also had significant inhibitory potency on both CYP2C9- and CYP3A4-mediated index reactions with IC(50) values of 105 and 62 micromol/L, respectively. Ginsenosides Rb1, Rb2, and Rc had limited inhibitory activities on both enzyme reaction systems, whereas the effects of ginkgolides A and B appeared negligible. It is concluded that the components of ginseng and ginkgo biloba screened are capable of inhibiting CYP2C9- and CYP3A4-mediated metabolic reactions. Our findings suggest that quercetin and ginsenoside Rd have the potential to interact with conventional medicines that are metabolized by CYP2C9 and CYP3A4 in vivo.
Aryl Hydrocarbon Hydroxylases↗