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Lester Packer - One of the best experts on this subject based on the ideXlab platform.

  • global gene expression analysis identifies cell and tissue specific actions of Ginkgo Biloba extract egb 761
    Cellular and Molecular Biology, 2002
    Co-Authors: Kishorchandra Gohil, Lester Packer
    Abstract:

    Clinical and pre-clinical uses of Ginkgo Biloba extract encompass a broad spectrum of pathologies that include peripheral arterial disorders, cardiovascular and neuronal dysfunctions and resolution of ischemia-reperfusion injuries. Many of these pathologies develop over time and recruit multiple cell types and molecular pathways that alter the cellular a nd molecular profiles of the failing targetorgans. Transcriptional processes are important determinants of the pathogenesis of these chronic disease states. Therefore the potential therapeutic and preventive actions of a standardized Ginkgo Biloba extract, EGb 761, may be affected through modulation of transcriptional processes. We have used various techniques for large-scale mRNA expression analysis, including differential display of mRNAs, cDNA arrays and high-density oligonucleotide arrays, to evaluate the actions of EGb 761 on the activities of the genomes in vitro and in vivo. The results show broad but cell specific actions of Ginkgo Biloba extract that may enhance antioxidant defenses in vitro in cancer cells and modulate neuronal functions in cortex and hippocampus in brain in vivo. The large scale analysis of mRNAs in response to Ginkgo Biloba extract in vitro and in vivo show that the standardized extract affects the activities of the mammalian genome. The data provide some support for the concept that the actions of EGb 761 are mediated through it effects on the process of gene transcription which plays a causative role in chronic diseases.

  • the in vivo neuromodulatory effects of the herbal medicine Ginkgo Biloba
    Proceedings of the National Academy of Sciences of the United States of America, 2001
    Co-Authors: Coran M H Watanabe, Lester Packer, Siegfried Wolffram, Peter Ader, Gerald Rimbach, John J Maguire, Peter G Schultz, Kishorchandra Gohil
    Abstract:

    Extracts of Ginkgo Biloba leaves are consumed as dietary supplements to counteract chronic, age-related neurological disorders. We have applied high-density oligonucleotide microarrays to define the transcriptional effects in the cortex and hippocampus of mice whose diets were supplemented with the herbal extract. Gene expression analysis focused on the mRNAs that showed a more than 3-fold change in their expression. In the cortex, mRNAs for neuronal tyrosine/threonine phosphatase 1, and microtubule-associated tau were significantly enhanced. Hyperphosphorylated tau is the major constituent of the neurofibrillary tangles in the brains of Alzheimer's disease patients. The expression of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-2, calcium and chloride channels, prolactin, and growth hormone (GH), all of which are associated with brain function, were also up-regulated. In the hippocampus, only transthyretin mRNA was upregulated. Transthyretin plays a role in hormone transport in the brain and possibly a neuroprotective role by amyloid-beta sequestration. This study reveals that diets supplemented with Ginkgo Biloba extract have notable neuromodulatory effects in vivo and illustrates the utility of genome-wide expression monitoring to investigate the biological actions of complex extracts.

  • antioxidant action of Ginkgo Biloba extract egb 761
    Methods in Enzymology, 1997
    Co-Authors: Lucia Marcocci, Marietherese Droylefaix, Lester Packer, Abdelhafid Sekaki, M Gardesalbert
    Abstract:

    Extracts from the leaves of Ginkgo Biloba trees have been used therapeutically for centuries in traditional Chinese medicine, and in modern Chinese pharmacopoeias both the leaves and fruits are recommended for treating problems of heart and lungs. EGb 761 is a dry, powdered extract prepared from Ginkgo Biloba leaves. It is a standardized mixture of several different chemical constituents; its two major classes of compounds are flavonoid glycosides and terpenoids (Drieu 1986; DeFeudis 1991). The flavonoid fraction is mainly composed of three flavonols: quercetin, kaempferol, and isorhamnetin, which are linked to a sugar(DeFeudis 1991). The terpenoid fraction is composed of Ginkgolides and Bilobalides(Drieu 1988). It also contains some organic acids, which help make it water-soluble(Drieu 1986).

  • the nitric oxide scavenging properties of Ginkgo Biloba extract egb 761
    Biochemical and Biophysical Research Communications, 1994
    Co-Authors: Lucia Marcocci, Marietherese Droylefaix, John J Maguire, Lester Packer
    Abstract:

    Ginkgo Biloba extract EGb 761 was found to be a scavenger of nitric oxide in in vitro acellular systems, under physiological conditions. EGb 761 competed with oxyhemoglobin for reaction with nitric oxide generated during the interaction of hydroxylamine with Complex I of catalase. An EGb 761 dose-dependent decrease in the amount of nitrite formed in the reaction of oxygen with nitric oxide produced from solution of 5 mM sodium nitroprusside was also observed. These data implicate it as a potential therapeutic agent in conditions of altered production of nitric oxide.

Marietherese Droylefaix - One of the best experts on this subject based on the ideXlab platform.

  • a Ginkgo Biloba extract egb 761 prevents mitochondrial aging by protecting against oxidative stress
    Free Radical Biology and Medicine, 1998
    Co-Authors: Juan Sastre, Arantxa Millan, Jose Garcia De La Asuncion, Rosa Pla, Gloria Juan, Federico V Pallardo, Enrique Oconnor, Jose Antonio Martin, Marietherese Droylefaix, Jose Vina
    Abstract:

    The effect of aging on indices of oxidative damage in rat mitochondria and the protective effect of the Ginkgo Biloba extract EGb 761 was investigated. Mitochondrial DNA from brain and liver of old rats exhibited oxidative damage that is significantly higher than that from young rats. Mitochondrial glutathione is also more oxidized in old than in young rats. Peroxide formation in mitochondria from old animals was higher than in those from young ones. According to morphological parameters (size and complexity), there are two populations of mitochondria. One is composed of large, highly complex mitochondria, and the other population is smaller and less complex. Brain and liver from old animals had a higher proportion of the large, highly complex mitochondria than seen in organs from young animals. Treatment with the Ginkgo Biloba extract EGb 761 partially prevented these morphological changes as well as the indices of oxidative damage observed in brain and liver mitochondria from old animals.

  • antioxidant action of Ginkgo Biloba extract egb 761
    Methods in Enzymology, 1997
    Co-Authors: Lucia Marcocci, Marietherese Droylefaix, Lester Packer, Abdelhafid Sekaki, M Gardesalbert
    Abstract:

    Extracts from the leaves of Ginkgo Biloba trees have been used therapeutically for centuries in traditional Chinese medicine, and in modern Chinese pharmacopoeias both the leaves and fruits are recommended for treating problems of heart and lungs. EGb 761 is a dry, powdered extract prepared from Ginkgo Biloba leaves. It is a standardized mixture of several different chemical constituents; its two major classes of compounds are flavonoid glycosides and terpenoids (Drieu 1986; DeFeudis 1991). The flavonoid fraction is mainly composed of three flavonols: quercetin, kaempferol, and isorhamnetin, which are linked to a sugar(DeFeudis 1991). The terpenoid fraction is composed of Ginkgolides and Bilobalides(Drieu 1988). It also contains some organic acids, which help make it water-soluble(Drieu 1986).

  • the nitric oxide scavenging properties of Ginkgo Biloba extract egb 761
    Biochemical and Biophysical Research Communications, 1994
    Co-Authors: Lucia Marcocci, Marietherese Droylefaix, John J Maguire, Lester Packer
    Abstract:

    Ginkgo Biloba extract EGb 761 was found to be a scavenger of nitric oxide in in vitro acellular systems, under physiological conditions. EGb 761 competed with oxyhemoglobin for reaction with nitric oxide generated during the interaction of hydroxylamine with Complex I of catalase. An EGb 761 dose-dependent decrease in the amount of nitrite formed in the reaction of oxygen with nitric oxide produced from solution of 5 mM sodium nitroprusside was also observed. These data implicate it as a potential therapeutic agent in conditions of altered production of nitric oxide.

Lucia Marcocci - One of the best experts on this subject based on the ideXlab platform.

  • antioxidant action of Ginkgo Biloba extract egb 761
    Methods in Enzymology, 1997
    Co-Authors: Lucia Marcocci, Marietherese Droylefaix, Lester Packer, Abdelhafid Sekaki, M Gardesalbert
    Abstract:

    Extracts from the leaves of Ginkgo Biloba trees have been used therapeutically for centuries in traditional Chinese medicine, and in modern Chinese pharmacopoeias both the leaves and fruits are recommended for treating problems of heart and lungs. EGb 761 is a dry, powdered extract prepared from Ginkgo Biloba leaves. It is a standardized mixture of several different chemical constituents; its two major classes of compounds are flavonoid glycosides and terpenoids (Drieu 1986; DeFeudis 1991). The flavonoid fraction is mainly composed of three flavonols: quercetin, kaempferol, and isorhamnetin, which are linked to a sugar(DeFeudis 1991). The terpenoid fraction is composed of Ginkgolides and Bilobalides(Drieu 1988). It also contains some organic acids, which help make it water-soluble(Drieu 1986).

  • the nitric oxide scavenging properties of Ginkgo Biloba extract egb 761
    Biochemical and Biophysical Research Communications, 1994
    Co-Authors: Lucia Marcocci, Marietherese Droylefaix, John J Maguire, Lester Packer
    Abstract:

    Ginkgo Biloba extract EGb 761 was found to be a scavenger of nitric oxide in in vitro acellular systems, under physiological conditions. EGb 761 competed with oxyhemoglobin for reaction with nitric oxide generated during the interaction of hydroxylamine with Complex I of catalase. An EGb 761 dose-dependent decrease in the amount of nitrite formed in the reaction of oxygen with nitric oxide produced from solution of 5 mM sodium nitroprusside was also observed. These data implicate it as a potential therapeutic agent in conditions of altered production of nitric oxide.

Uwe Fuhr - One of the best experts on this subject based on the ideXlab platform.

Yves Christen - One of the best experts on this subject based on the ideXlab platform.

  • Ginkgo Biloba extract egb 761 in alzheimers disease is there any evidence
    Current Alzheimer Research, 2007
    Co-Authors: Charles Ramassamy, Fanny Longpre, Yves Christen
    Abstract:

    For centuries, extracts from the leaves of the Ginkgo Biloba tree have been used as Chinese herbal medicine to treat a variety of health disorders. The standardized Ginkgo Biloba extract EGb 761 was marketed in France and Germany 30 years ago for various vascular and cerebral deficits and is now classified as a food supplement in the United States. EGb 761 is currently the focus of phase-III clinical trials, GEM and GuidAge studies, to evaluate its efficacy on the prevention of Alzheimers disease (AD) in subjects over 70 years old. This review summarizes recent advancements in our understanding of the potential role of EGb 761 in the prevention of AD. Besides its well-known free radical scavenging properties, the ability of EGb 761 to protect neurons probably also involves other intracellular pathways. We will point out potential targets of EGb 761 in the amyloid cascade such as its antiamyloidogenic properties or the regulation of gene expression. Moreover we will discuss the complexity of the cellular and molecular mechanisms of EGb 761 and the significance of the synergic effect of different constituents of EGb 761.