Wikipedia
Linking
Google
Scholar Search
Drug
Information Portal (U.S. National Library of Medicine) - Bilobalide
PubChem
Compound
Summary
- Bilobalide
Drug
Bank - Bilobalide
KEGG
(Kyoto Encyclopedia of Genes and Genomes) - Bilobalide
http://www.ebi.ac.uk/chebi/
- Bilobalide
http://www.ncbi.nlm.nih.gov/
- Bilobalide
http://sydney.edu.au/ The
sesquiterpene trilactone bilobalide is one of the active
constituents of the 50:1 Ginkgo biloba leaf extract
widely used to enhance memory and learning. Bilobalide
was found to antagonise the direct action of g-aminobutyric
acid (GABA) on recombinant a1h2g2L GABAA receptors.
The effect of bilobalide on the direct action of GABA
at a1h2g2L GABAA receptors expressed in Xenopus laevis
oocytes using two-electrode voltage-clamp method was
evaluated and compared with the effects of the classical
GABAA receptor competitive antagonist bicuculline and
noncompetitive antagonist picrotoxinin. Bilobalide (IC50
= 4.6F0.5 AM) was almost as potent as bicuculline and
pictrotoxinin (IC50 = 2.0F0.1 and 2.4F0.5 AM, respectively)
at a1h2g2L GABAA receptors against 40 AM GABA (GABA
EC50). While bilobalide and picrotoxinin were clearly
noncompetitive antagonists, the potency of bilobalide
decreased at high GABA concentrations suggesting a component
of competitive antagonism.
http://www.columbia.edu/ Ginkgo
biloba, the ginkgo tree, is the oldest living tree,
with a long history of use in traditional Chinese medicine.
In recent years, the leaf extracts have been widely
sold as phytomedicine in Europe and as a dietary supplement
worldwide. Effects of Ginkgo biloba extracts have been
postulated to include improvement of memory, increased
blood circulation, as well as beneficial effects to
sufferers of Alzheimer's disease. The most unique components
of the extracts are the terpene trilactones, that is,
ginkgolides and bilobalide. These structurally complex
molecules have been attractive targets for total synthesis.
Terpene trilactones are believed to be partly responsible
for the neuromodulatory properties of Ginkgo biloba
extracts, and several biological effects of the terpene
trilactones have been discovered in recent years, making
them attractive pharmacological tools that could provide
insight into the effects of Ginkgo biloba extracts.
Local Ginkgo biloba extract contain specific terpenoids
called ginkgolides (ginkgolide A, ginkgolide B, ginkgolide
C - diterpenes)
and bilobalide (pentanorditerpene). Ginkgolide A (GA) and ginkgolide B (GB) are
the main molecular forms of ginkgolides. These compounds are non-competitive
antagonists of the GABAA and glycine receptors, and
are structurally related to picrotoxin (PTX), also a
non-competitive antagonist of these receptors. These
compounds are thought to bind in the channel of these
receptors. The medical
benefits of GINKGO BILOBA EXTRACT rely primarily on two groups of active
components: the ginkgo flavone glycosides and the terpene lactones. The
ginkgo flavone glycoside designation on GBE labels indicates the carefully
measured balance of bioflavonoids. These bioflavonoids are primarily responsible
for GBE's antioxidant activity and ability to inhibit platelet aggregation.
These two actions may help GBE prevent circulatory diseases such as
atherosclerosis and support the brain and central nervous system. The unique
terpene lactone components found in GBE, known as ginkgolides and bilobalide
typically make up 6% of the extract. They are associated with increased
circulation to the brain and other parts of the body as well as exert a
protective action on nerve cells. Ginkgolides may improve circulation and
inhibit platelet-activating factor. Bilobalide is known to protect the cells of the nervous
system.
|