Transcript What is Curcumin

CURCUMIN FROM TURMERIC AS A
DRUG CANDIDATE FOR ALZHEIMER’S DISEASE
P.B. Tirupathi Pichiah
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The Turmeric
Rhizomatous herbaceous perennial plant
Ginger family
Used as a spice in Indian, Persian, Thai and Malay dishes, not only in curry, but also in
masak lemak, rendang and many more.
Used for dyeing fabrics,
Active ingredient is curcumin and it has a distinctly earthy, slightly bitter,
slightly hot peppery flavor and a mustardy smell.
Most usage of turmeric is in the form of root powder.
Erode (Yellow City), a city in the south Indian state of Tamil Nadu, is the world's largest
producer and most important trading center of turmeric in Asia.
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The curcumin solution or curcumin powder dissolved in alcohol is used for
coloring products. Such as in pickles, relishes, and mustard.
Turmeric has been used to color cheeses, yogurt, dry mixes, salad dressings, butter
and margarine (Like Butter).
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Uses in folk medicine
Ayurvedic practices : antiseptic for cuts, burns and bruises. Turmeric mixed in milk for fever.
Asian countries : dietary supplement, which allegedly helps with stomach problems and
other ailments.
Japan :Popular as a tea in Okinawa.
Pakistan: Also use it as an anti-inflammatory agent, and remedy for gastrointestinal
discomfort associated with irritable bowel syndrome, and other digestive disorders.
Afghanistan , India and northwest Pakistan : Turmeric Paste applied in wound
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COSMETICS
SOAP
FACE WASH
SKIN CREAM
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Importance of Turmeric in Indian Culture and Tradition:
Used in various rituals
wedding ceremony
South Indian festival Pongal,
Used to prepare special sweet dishes Patoleo
In South Indian marriage ritual, a piece of dried turmeric tied with string is sometimes
used to replace the Thali necklace temporarily.
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Curcumin has a wide range of application:
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PRELIMINARY MEDICAL RESEARCH
Turmeric is currently being investigated for possible benefits in Alzheimer's disease
cancer, arthritis, and other clinical disorders.
The U.S. National Institutes of Health currently has registered 19 clinical trials
underway to study use of dietary turmeric and curcumin for a variety of clinical
disorders (dated February 2010).
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What is Curcumin ?
Curcumin is the principal curcuminoid of the popular Indian spice
turmeric, which is a member of the ginger family (Zingiberaceae).
Curcuminoids are Polyphenols, Responsible for yellow color of turmeric.
Three major curcuminoids —
1.Curcumin, 2.Demethoxycurcumin and 3.Bisdemethoxycurcumin
— occur naturally in these Curcuma species.
Chemistry
Aromatic ring systems, which are polyphenols are connected by two α,β-unsaturated
carbonyl groups.
Two carbonyl groups form a diketone.
The diketone form stable enols or are easily deprotonated and form enolates, while the
α,β-unsaturated carbonyl is a good Michael acceptor and undergoes nucleophilic
addition.
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“DiKetone General Form”
Curcumin in Ketoform
Ketone General Form
Enol General Form
Curcumin in Enol Form:
Enols are alkenes with a hydroxyl group affixed to one of the carbon atoms composing
the double bond
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Biological Properties of Curcumin :
Anti-inflammatory effects by interrupting NF-κB signaling.
Scavenging of ROS :
Potent scavenger of ROS, including superoxide anions, hydroxyl radicals, singlet
oxygen, 8 nitric oxide and peroxynitrite.
Protect lipids, hemoglobin and DNA against oxidative degradation.
Potent inhibitor of ROS-generating enzyme Cyclooxygenase and Lipoxygenase in mouse
epidermis
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Inhibition of Carcinogenesis
Inhibits chemical carcinogenesis at different tissue sites in several experimental animal models.
Curcumin in the diet decreased the number of azoxymethane (AOM) induced colon
tumors in mice and rat.
Topical application of curcumin strongly inhibited tumor production in the skin of mice applied
with (7,12-dimethylbenz[α] anthracene (DMBA) [CARCINOGEN] .
Induction of Apoptosis
Induces apoptosis in several tumor cell lines.
Curcumin-induced apoptosis is highly dependent on the origin and malignancy of the
cell lines.
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Curcumin treatment resulted in increase in the protein levels of Bax and Bak, and
mitochondrial translocation and activation of Bax in fibroblast to trigger a drop in
mitochondrial membrane potential, cytosolic release of apoptogenic molecules
(cytochrome c, etc.), activation of caspase-9 and caspase-3, and ultimately induction of
apoptosis.
Neuroprotective Effects of Curcumin
Neurodegenerative diseases result in the loss of functional neurons and synapses.
Curcumin has an outstanding safety profile and a number of pleiotropic actions with
potential for neuroprotective efficacy, including anti-inflammatory, antioxidant,
and anti-protein-aggregate activities.
Dietary curcumin is a strong candidate for use in the prevention or treatment of major
disabling age-related neurodegenerative diseases like Alzheimer’s, Parkinson’s, and
stroke.
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MOLECULAR TARGETS OF CURCUMIN
Curcumin possesses an anti-inflammatory activity and is a potent inhibitor of ROSgenerating enzymes such as lipoxygenase, cyclooxygenase, xanthine oxidase and
inducible nitric oxide synthase (iNOS).
Potent inhibitor of
protein kinase C (PKC),
EGFR-tyrosine
Ι-κB kinase.
NF-κB
And also, c-jun, c-fos, c-myc, NIK, MAPKs, ERK, ELK,
PI3K, Akt, CDKs, and iNOS.
It is considered that PKC, mTOR and EGFR tyrosine kinase are the major upstream
molecular targets for curcumin
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CLINICAL APPLICATION OF CURCUMIN
Cancer. rheumatoid arthritis, atherosclerosis, chronic pancreatitis,
psoriasis,hyperlipidemia, and neurodegenerative diseases.
Curcumin significantly decreases serum cholesterol concentration.
Curcumin treatments stimulated immune clearance of
amyloidosis in AD brain, suggesting a potential neuropreventive role.
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Neuroinflammation in Alzheimer’s disease: different molecular
targets and potential therapeutic agents including curcumin
Balmiki Ray and Debomoy K Lahiri
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Born on the 14TH June 1864 in Marktbreit am
Main (Germany) and died in Breslau (now
Wroclaw, Poland).
Fathers of neuropathology,
Alois Alzheimer
CLICK
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Alzheimer’s disease (AD) : A brief Introduction
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Degeneration of Central Nervous System and a common form of dementia.
Incurable, degenerative, and terminal disease
Alois Alzheimer in 1906
In 2006, there were 26.6 million sufferers worldwide. Alzheimer's is predicted to affect
1 in 85 people globally by 2050.
Observable symptoms :
inability to acquire new memories, difficulty in recalling recently , confusion, irritability
and aggression, mood swings, language breakdown, long-term memory loss, and
the general withdrawal of the sufferer as their senses decline
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AD patients is caused by at least two distinct characteristic events, deposition of
the amyloid beta (Ab) peptide in the intercellular space and formation of intraneuronal tangle owing to hyperphosphorylation of axonal Tau protein .
Amyloid beta and associated reactive oxygen species (ROS) mediated
neuronal damage is one of the major hallmarks of AD,
Pathological stages
Stage I: Mild involvement that is confined to the transentorhinal region.
Stage II: Lesion gradually increases and the pathology extends to entorhinal
region.
Stage III: Pathology in entorhinal region worsens and lesions extend to
adjoining neocortex.
Stage IV: Neurofibrillary pathology extends up to medial temporal
gyrus.
Stage V: Lesion extends up to occipital neocortex.
Stage VI: Lesions visible in striate and parastriate areas of occipital neocortex.
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Early and late onset AD
Based on genetic etiology :
1.Familial form or Early Onset Alzheimer’s disease (EOAD) that occurs before
65 years of age
2.Late Onset Alzheimer’s Disease (LOAD) that occurs after 65 years of age and
is usually sporadic.
Amyloid β precursor protein (APP) and presenilin (PS) 1 and 2 are considered
closely involved in the etiology of familial AD.
Apolipoprotein E (APOE) gene has three common alleles, epsilon 2 (ε2),
epsilon 3 (ε3), and epsilon 4 (ε4).
The ε2 allele is considered protective but presence of the e4 is considered a
risk factor for developing LOAD.
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ε4 allele increases the risk for AD from 20% to 90% and decreases the age of onset
from 84 to 68 years depending on gene dose of ε4 alleles.
Key molecules in the pathogenesis of AD
Amyloid β precursor protein :
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mammalian transmembrane protein

695–770 amino acid residues

Large ectocytoplasmic N-terminus domain and a shorter intracytoplasmic carboxylterminal region.

Cleaved by b-site APP cleaving enzyme 1 (BACE1) to produce sAPPb and a Cterminal fragment containing 99 amino acid residues (C99)
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C99 is further cleaved by γ secretase to produce Aβ peptides of varying numbers
of amino acid residues.
A β with a forty amino acid residue Aβ (1–40) is the most abundant form and is less
pathogenic for the development of AD.
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Aβ with 42 amino acid residue Aβ (1–42), which is produced in much lower quantities,
is fibrilar in nature and forms aggregates that is pathognomonic in AD.
BACE-1:
Catalyzes the initial step of C99 cleavage to form Aβ peptide
APO-E:
lipoprotein that is part of chylomicrons, LDL and HDL and participates in the transport
of lipids, particularly cholesterol.
APOE e4 allele is related to an increased risk of AD.
A potential function of ApoE in CNS is to decrease Aβ aggregation.
APOEe4 has hyper-inflammatory properties leading to neuronal damage in AD brain
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Inflammations in AD
Aβ and concurrent ROS production synergistically
increases the damage to the neurons.
Glial (astrocyte) reactivation occurs around plaques
to take up Aβ and neuronal debris.
Activated astrocytes are also involved in plaque
formation.
interaction of microglia with Aβ peptide gives rise to
ROS.
activation of complement cascade forms
membrane attack complexes, which not only
cause substantial damage to the neurons but also
can lead to phosphorylation of Tau protein
leading to formation of neurofibrillary tangles
Nature Medicine - 12, 885 - 887 (2006)
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Role of nuclear factor k beta (NFkB)
Responsible for regulation in cytokine production.
NFkB stays inactivated by an inhibitory protein IkB.
Once activated, NFkB enters the nucleus and increases the transcription of different
inflammatory mediators.
TNFa, Aβ, and secreted APP activates NFkB.
NFkB sites are present in the regulatory (promoter) region of APP, PS, and
BACE-1 genes.
An activation of NFkB increases transcription of APP and BACE-1, which eventually leads to
increase in Aβ production.
Presence of APOE e4 increases NFkB level
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APOE gene promoter study showed that Aβ can stimulate APOE through NFkBdependent pathway.
Role of peroxisome proliferator-activated receptor-γ (PPAR γ)
Ligand-dependent nuclear hormone receptor transcription factor.
Regulates inflammatory responses in different organ systems including CNS.
PPARg binds to peroxisome proliferator response element (PPRE) within the promoter
regions of targeted genes of inflammatory mediators in T cells, such as TNFa, IL-10, IFNgamma, and IL-4, and regulates their expression
PPARg suppresses Aβ mediated induction of microglial cells from producing proinflammatory cytokines, also inhibits NFkB mediated inflammatory pathways by
reducing its nuclear translocation.
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Role of signal transducer and activator of transcription-1 (STAT-1)
STAT-1 is a transcription factor - binding sites in the
APP and BACE-1 gene promoter regions.
Activated STAT-1 accelerated Aβ formation.
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Current FDA approved drugs for the treatment of AD
Role of cholinesterase inhibitors (ChEI)
Lowers inflammatory infiltration caused by T cells and microglia in CNS of
transgenic mouse and to decrease the production of inflammatory cytokines
TNF-a and IFN-gamma, which are involved in inflammatory response followed by
neuronal damage in AD brain.
Donepezil treatment for 10mg/d (30d) reduce IL and TNF, measured in pheripheral
blood mononuclear cells of AD patients.
Cholinesterase promotes formation of Aβ peptide causing neuroinflammation.
Acetylcholinesterase inhibitors reduces Aβ load and subsequent neuroinflammation.
Some adverse effects nausea, vomiting, diarrhea, anorexia, headache, syncope,
abdominal pain, and dizziness ,and therefore, the discovery of more novel drug targets
is needed for AD treatment.
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Role of NMDA (N-methyl D-aspartate) receptor and antagonists
-NMDA are ionotropic glutamate receptors in CNS.
-Allows entry of calcium ions into the neurons and can cause excitatory
damage.
-Memantine, a noncompetitive NMDA receptor antagonist.
-Used for treatment of moderate to severe AD.
-Protect neurons from neuroinflammation caused by activated macrophage and
glutamate excitotoxicity.
-Memantine also reduce the production of Aβ in rat primary cortical neurons.
-Memantine has nicotinic antagonistic properties that restrict its use in early phase
of AD.
Rosi et al Study:
Rat 4th Ventricle
LPS
neuroinflamation
Memantine treatment
Control
Microglia
Microglia
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Role of non steroidal anti-inflammatory drugs (NSAIDs)
Prolonged use of NSAIDs with nonselective COX inhibition (both 1 and 2) can have
several adverse effects such as gastrointestinal hemorrhage.
Selective COX2 inhibitor (Celecoxib) were tested in transgenic mouse model of AD did
not showed significant improvement.
Role of statins
Inhibit HMG-CoA, the rate-limiting enzyme in cholesterol biosynthesis.
Anti-inflammatory, antiapoptotic, immunomodulatory, antithrombotic effects that are
collectively termed as ‘pleotrophic effects’.
In AD brain, reduced production of a potent vasodilator ‘endothelial nitric oxide
synthase’
Statins upregulating eNOS, decrease the inflammation related to Aβ deposition.
Clinical trial failure.
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Role of PPARg agonists
-Activation of PPARg can be beneficial in the treatment of neuroinflammation
associated with AD.
-PPARg agonists (e.g. pioglitazone and rosiglitazone) can be useful.
-low penetration of blood brain barrier.
Use of γ secretase inhibitor to block the Aβ -mediated amyloidogenic pathways
The enzyme γ secretase is involved in the final cleavage of C99 fragment to
produce Aβ peptide.
γ secretase inhibitor LY450139 dose-dependently decreases Aβ production
in human CNS.
Another placebo control phase I clinical trial with a g secretase inhibitor
MK0752 has recently been carried out by Merck & Co. Inc. But result not yet
published.
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Alternative strategies
Herbal, natural products, and pineal hormone melatonin
Ginkgo biloba ( 은행 ):
Meta analysis of those studies revealed no convincing
evidence that Ginkgo biloba is effective in the
treatment of dementia and cognitive impairment
Huperzine A:
An alkaloid compound found in the plant Huperzia serrata.
AChEI activity.
Some preclinical studies showed that it can protect cells
from ROS-mediated damage caused by Aβ aggregation.
systematic review and meta analysis study found insufficient
evidence
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Garlic compounds:
Aged garlic extract and a garlic derived compound ‘s-allyl cysteine’ showed significant
improvement in hippocampal-based memory tasks in transgenic mice models.
Protects ROS-mediated insults.
Melatonin:
Aβ lowering agent and free radical scavenger.
Melatonin treatment decreases the levels of both secreted APP (sAPP) and APP
mRNA in cell culture and potentiate neuronal differentiation.
Melatonin was found to decrease the levels of cortical Ab in mice and was also
shown to protect neuronal cells from NOS mediated generation of superoxide free
radicals.
Melatonin is in phase II clinical trial.
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Recent Papers Published on “ Curcumin and Alzheimer”
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Molecular targets of curcumin in the treatment of neuroinflammation in AD
Lim et al. Study:
1.Curcumin decreases Aβ -ROS related inflammation and Ab burden in APP
transgenic mice.
2. Decrease IL-1b level
3. Decreases activated glial marker GFAP.
4. Decreases microglial activation in hippocampal and cortical layers of the
mouse brain.
5. Decreases the level of insoluble Aβ and plaque burden in cortex and
hippocampus of the transgenic mice.
Frautschy et al. Study:
1. Improves synaptic transmission in old female rats by retaining synaptophysin, in
curcumin diet animal, which were lost in control animals when
intracerebroventricular infusion of Aβ was given to both the group.
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Yin et al.
Aβ -induced mitochondrial damage and subsequent cell death (apoptosis) in
mouse cerebral endothelial cell related to BIM overproduction.
AP-1 regulated BIM expression, inhibition of AP-1 reduces BIM expression.
Curcumin protects CEC from Ab mediated toxicity because of its potent role
in AP-1 inhibition.
Piper et al.
Curcumin enhances the activity of detoxifying enzymes like glutathione-Stransferase in male rats.
Motterlini et al.
Curcumin upregulate endothelial HO-1 gene and protein expression and
protect them from peroxide mediated toxicity.
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Begum AN, et al:
Inducible nitric oxide synthase (iNOS)-mediated production of reactive
nitrogen species (RNS) and ROS cause neuronal damage in AD. curcumin and
tetrahydrocurcumin (THC) significantly decrease production of both iNOS protein
and mRNA in transgenic mouse brain.
Baum L and Ng A :
Increase in the concentration of copper, zinc, and iron in Aβ plaque, play an
important role in the aggregation of Aβ and subsequent ROS production metal
chelation activity of curcumin and they showed that curcumin can bind with
copper and iron ions and act as a chelator and suggested reduced Aβ plaque and
subsequent ROS generation .
Becaria A, et al:
induction of NFkB can occur in the presence of copper that can be
prevented by the chelation activity of curcumin
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Giri RK et al:
Aβ and Aβ (1–42) treatment can increase mRNA expression of TNF-a, MIP-1b, IL-1b,
MCP- 1, and IL-8 in monocytes. curcumin reduces Aβ mediated expression of the
cyrochemokines, and it also decreases the phosphorylation of ERKs and expression of Egr-1 in a dose-dependent manner.
Atamna and Boyle study:
Aβ binds with heme with high affinity and this Aβ -heme complex acts like a peroxidase,
which can cause oxidative damage in the brain ,curcumin inhibits Ab-heme peroxidase
in a dose-dependent way.
Suh HW et al:
Aβ and glutamate-induced neurotoxicity may perhaps result from JNK activation. By
suppressing JNK activation, curcumin exerts its role in preserving
Neurons.
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Peschel et al.
Curcumin dose dependently increases the expression of LDL-R mRNA in
HepG2 cells, which would result in a higher net uptake of LDL-cholesterol to the
liver from plasma .Excessive circulatory cholesterol increase brain APOE and as already
discussed, APOE may play a role in the pathogenesis of AD.
Kin et al.
Low dose of curcumin stimulates proliferation of neural stem cells in mouse embryonic
cortical culture as well as in the hippocampus of adult mouse
Stimulation of neural stem cells is due to activation of ERK and p38 kinases by the
action of curcumin.
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Curcumin increases neuronal cell viability and neurite formation at a non-toxic dose
Neuronal pheochromocytoma (PC12) cells
30 nM of nerve growth factor (NGF) [15d]
neuronal differentiation.
curcumin.
48h
250 nM,
500 nM,
1 µM
Viability Test/ Toxicity Test/Morphology Study
Cell Titer Glo Assay
LDH assay
fixed by using 4% paraformaldehyde
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CTG assay showed a significant increase in viability of cells treated with 250 nM
and 500 nM doses of curcumin where as 1 μM dose of curcumin did not show any
change in cell viability compared to the vehicle.
LDH assay was performed that revealed that 250 nM and 500 nM curcumin in
conditioned media sample was non-toxic to the cells. However, secreted LDH level
from the cells treated with 1 µM curcumin is insignificantly higher than that of
vehicle and other two doses of curcumin
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Curcumin increases neurite formation in cultured neuronal cells
Morphology pictures of the cells showed more neurite outgrowth in the cells
treated with 250 nM and 500 nM of curcumin (green represents a tubulin/
whole cell body and blue represents DAPI/nuclei) than the control
[A neurite refers to any projection from the cell body of a neuron.]
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Role of curcuminoid compounds in AD
Major constituents of turmeric extract are:
curcumin (~4.4%), = Already disscussed
desmethoxycurcumin (~ 2.4%), = potent acetylcholine esterase property
bisdesmethoxycurcumin (~3.6%). = potent acetylcholine esterase property, increases the
transcription of genes for MGAT3 and TLRs
[Downregulation of genes such as 1, 4-mannosyl-glycoprotein 4-N-acetylglu- cosaminyltransferase
(MGAT3) and toll like receptors (TLRs) in mononuclear cells in AD patients is related to insufficient
clearance of Aβ from brain interstitial space]
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http://clinicaltrials.gov/ct2/show/study/NCT00099710
Curcumin in clinical studies
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Curcumin in clinical studies
Curcumin at dose of 2000 mg/day and 4000 mg/day in patients suffering
from mild to moderate AD vs. age-matched healthy controls.
Looked at different AD markers like levels of Aβ and tau proteins in CSF
samples.
Outcome of this study has not yet been published.
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Bioavailability of curcumin
Curcumin is sparingly soluble in water
In a phase I trial, serum concentration of curcumin was 0.51 ( 0.11) mM, 0.63
( 0.06) mM, and 1.77 ( 1.87) mM after ingestion of 1000 mg, 2000 mg, and
4000 mg of curcumin, respectively.
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Nanocurcumin: a potential source of more biovailable form of curcumin
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What we learnt till now ?
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Conclusion
We had discussed potential roles of curcumin in the treatment of neuroinflammation
associated with AD.
We had discussed outcomes of couple of clinical trials of curcumin in AD and demented
patients. Unfortunately, none of them showed a dramatic improvement in the
symptoms. Low absorption of curcumin through oral route may be a cause for that.
we have also discussed some beneficial anti-inflammatory roles for curcuminoid
substances found in turmeric.
A carrier mediated transport or nanotechnology based delivery system can increase
the bioavailability of curcumin that will potentiate its effect and these are the areas
going to bear enormous importance in future research.
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Some Interesting Facts
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Higher Education, Lower Alzheimer’s Risk
GSK Biological’s : AFFiRiS’s Alzheimer’s vaccine AD02 to be studied in European patients
Nasal spray clears Alzheimer's brain plaques (Howard Weiner et al).
Intranasal Insulin and Memory in Early Alzheimer's Disease.
A variant of the fat mass and obesity associated (FTO) gene causes both weight gain
and brain tissue loss.
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