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Therapeutic Applications of Citicoline for Stroke and Cognitive Dysfunction in the Elderly: A Review of the Literature

Authors:
  • AIBMR Life Sciences Inc.

Abstract and Figures

Citicoline (CDP-choline; cytidine 5'-diphosphocholine), a form of the essential nutrient choline, shows promise of clinical efficacy in elderly patients with cognitive deficits, inefficient memory, and early-stage Alzheimer's disease. Citicoline has also been investigated as a therapy in stroke patients, although the results of trials to date are inconclusive. Produced endogenously, citicoline serves as a choline donor in the metabolic pathways for biosynthesis of acetylcholine and neuronal membrane phospholipids, chiefly phosphatidylcholine. The principal components of citicoline, choline and cytidine, are readily absorbed in the GI tract and easily cross the blood-brain barrier. Exogenous citicoline, as the sodium salt, has been researched in animal experiments and human clinical trials that provide evidence of its cholinergic and neuroprotective actions. As a dietary supplement, citicoline appears useful for improving both the structural integrity and functionality of the neuronal membrane that may assist in membrane repair. This review, while not intended to be exhaustive, highlights the published, peer-reviewed research on citicoline with brief discussions on toxicology and safety, mechanisms of action, and pharmacokinetics.
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Alternative Medicine Review
Volume 9, Number 1 2004 Page 17
Review Citicoline
Abstract
Citicoline (CDP-choline; cytidine 5’-
diphosphocholine), a form of the essential
nutrient choline, shows promise of clinical
efficacy in elderly patients with cognitive
deficits, inefficient memory, and early-stage
Alzheimer’s disease. Citicoline has also been
investigated as a therapy in stroke patients,
although the results of trials to date are
inconclusive. Produced endogenously,
citicoline serves as a choline donor in the
metabolic pathways for biosynthesis of
acetylcholine and neuronal membrane
phospholipids, chiefly phosphatidylcholine.
The principal components of citicoline, choline
and cytidine, are readily absorbed in the GI tract
and easily cross the blood-brain barrier.
Exogenous citicoline, as the sodium salt, has
been researched in animal experiments and
human clinical trials that provide evidence of
its cholinergic and neuroprotective actions. As
a dietary supplement, citicoline appears useful
for improving both the structural integrity and
functionality of the neuronal membrane that
may assist in membrane repair. This review,
while not intended to be exhaustive, highlights
the published, peer-reviewed research on
citicoline with brief discussions on toxicology
and safety, mechanisms of action, and
pharmacokinetics.
(Altern Med Rev 2004;9(1):17-31)
Therapeutic Applications of
Citicoline for Stroke and
Cognitive Dysfunction in the Elderly:
A Review of the Literature
Richard Conant, MAc, CN, and
Alexander G. Schauss, PhD
Introduction
Citicoline is a complex organic molecule
(Figure 1) that functions as an intermediate in the
biosynthesis of cell membrane phospholipids.
Citicoline is also known as CDP-choline and cy-
tidine diphosphate choline (cytidine 5’-
diphosphocholine). CDP-choline belongs to the
group of biomolecules in living systems known
as “nucleotides” that play important roles in cel-
lular metabolism. The basic structure of a nucle-
otide contains ribose with a nitrogenous base and
a phosphate group. CDP-choline is composed of
ribose, pyrophosphate, cytosine (a nitrogenous
base), and choline.
1
Grouped with the B vitamins, choline is a
trimethylated nitrogenous base that enters three
major metabolic pathways: (1) phospholipid syn-
thesis via phosphorylcholine; (2) acetylcholine
synthesis; and (3) oxidation to betaine, which
serves as a methyl donor. Endogenously, forma-
tion of citicoline is the rate-limiting step in the
synthesis of phosphatidylcholine, a key membrane
Alexander G. Schauss, PhD, FACN – Director of the Life
Sciences Division of the American Institute for Biosocial
and Medical Research, Inc. (AIBMR) in Puyallup, WA;
adjunct research professor of botanical medicine National
College of Naturopathic Medicine in Portland, Oregon.
Correspondence address: 4117 S. Meridian, Puyallup, WA
98373
Email: info@abmi.com
Richard Conant, MAc, CN – Vice President of Technical
and Regulatory Affairs in the Life Sciences Division of the
American Institute for Biosocial and Medical Research, Inc.
(AIBMR); Masters degree in acupuncture from the
Northwest Institute of Acupuncture and Oriental Medicine.
AIBMR has coordinated nonclinical toxicology studies for
Kyowa Hakko USA, a manufacturer of citicoline.
Page 18 Alternative Medicine Review
Volume 9, Number 1 2004
Citicoline Review
Copyright©2004 Thorne Research, Inc. All Rights Reserved. No Reprint Without Written Permission
phospholipid, from choline. Exogenous citicoline,
which is hydrolyzed in the small intestine and
readily absorbed as choline and cytidine, enters
the various biosynthetic pathways that utilize
citicoline as an intermediate. Citicoline thus has a
sparing effect on systemic choline reserves, as well
as inhibiting the breakdown of membrane phos-
pholipids.
2
Citicoline is produced from choline chlo-
ride and orotic acid by an enzymatic process. Free-
base citicoline is the form marketed as a dietary
supplement in the United States and as a drug in
Japan. The sodium salt of citicoline, the form used
in clinical trials, is sold as a drug in Europe.
Pharmacokinetics and Metabolism
Citicoline is a water-soluble compound
with greater than 90-percent bioavailability.
3
Phar-
macokinetic studies on healthy adults have shown
oral doses of citicoline are rapidly absorbed, with
less than one percent excreted in feces. Plasma
levels peak in a biphasic manner, at one hour after
ingestion followed by a second larger peak at 24
hours post-dosing. Citicoline is metabolized in the
gut wall and liver. The byproducts of exogenous
citicoline formed by hydrolysis in the intestinal
wall are choline
and cytidine. Fol-
lowing absorp-
tion, choline and
cytidine are dis-
persed through-
out the body, en-
ter systemic cir-
culation for utili-
zation in various
biosynthetic path-
ways, and cross
the blood-brain
barrier for re-syn-
thesis into
citicoline in the
brain.
4
Pharma-
cokinetic studies
using
14
C
citicoline show
citicoline elimi-
nation occurs mainly via respiratory CO
2
and uri-
nary excretion, in two phases mirroring the
biphasic plasma peaks. The initial peak in plasma
concentration is followed by a sharp decline,
which then slows over the next 4-10 hours. In the
second phase, an initially rapid decline after the
24-hour plasma peak is similarly followed by a
slower elimination rate. The elimination half-life
is 56 hours for CO
2
and 71 hours for urinary ex-
cretion.
5
Endogenous citicoline serves as an inter-
mediate in the biosynthesis of phospholipids, in-
cluding phosphatidylcholine, the primary phos-
pholipid in cell membranes.
6
Cytidine, a major
component of RNA, undergoes cytoplasmic con-
version to cytidine triphosphate (CTP). In the
citicoline metabolic pathway, choline is phospho-
rylated by the enzyme choline kinase; the result-
ing phosphorylcholine combines with CTP to form
citicoline.
7
Citicoline then combines with
diacylglycerol (DAG), forming phosphatidylcho-
line, with choline phosphotransferase serving as
the enzyme catalyst in this reaction.
3
Oral administration of citicoline raises
plasma levels of cytidine and choline in rats within
Figure 1. Structure of Citicoline
CH
3
NH
2
N
O
OH OH
OO
P
O
OH
N
O
O
P
O
O
-
N
+
CH
3
CH
3
From: Secades JJ, Frontera G. Meth Find Exp Clin Pharmacol 1995;17(Suppl. B):1-54.
Alternative Medicine Review
Volume 9, Number 1 2004 Page 19
Review Citicoline
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six to eight hours. Prolonged administration for
42 and 90 days increases brain concentrations of
phosphatidylcholine, phosphatidylethanolamine,
and phosphatidylserine – the three major phospho-
lipids in brain cell membranes. Evidence for the
role of these metabolites as substrates for phos-
phatidylcholine synthesis was found in a study
giving rats daily oral doses of citicoline for 90
days. At a dose of 500 mg/kg per day phosphati-
dylcholine levels increased by 25 percent, phos-
phatidylethanolamine by 17 percent, and
phosphatidylserine by 42 percent.
8
Administration of citicoline to aged rats
activates CTP:phosphocholine cytidylyl-
transferase, the rate-limiting enzyme in the
citicoline pathway of phosphatidylcholine synthe-
sis in the brain cell membrane.
9
Choline and cyti-
dine are the major metabolites released via hy-
drolysis of citicoline during absorption.
A single oral dose of citicoline raises
plasma choline levels in both younger and older
subjects. Using protein magnetic resonance spec-
troscopy, it was found that brain choline levels in
older subjects decreased after citicoline adminis-
tration, but increased in younger subjects. The
postulated explanation is that the cytidine moiety
of citicoline may be taken up by brain cells in older
adults more rapidly than choline. Based on this
finding, it is suggested that cytidine is the citicoline
component primarily responsible for stimulating
phosphatidylcholine synthesis in older subjects.
10
Using protein-decoupled phosphorus magnetic
resonance spectroscopy, it has been shown that
citicoline administration to older subjects for six
weeks increases brain levels of phosphodiesters,
byproducts of phospholipid metabolism. This is
seen as evidence that citicoline increases phospho-
lipid synthesis and turnover, which may help re-
verse cognitive functional deficits associated with
aging.
11
In clinical trials, citicoline has been ad-
ministered orally and by intramuscular injection.
Mechanisms of Action
Phospholipid Precursor
The pharmacological action of citicoline
appears to involve mechanisms that extend beyond
phospholipid metabolism. Citicoline metabolites
– choline, methionine, betaine, and cytidine-de-
rived nucleotides – enter a number of metabolic
pathways. Evidence of citicoline’s role as a phos-
phatidylcholine precursor has been found in ani-
mal studies.
12
Biochemical markers of cholinergic nerve
transmission are known to be deficient in condi-
tions characterized by degeneration of cholinergic
neurons, such as Alzheimer’s disease (AD).
Citicoline modestly improves cognitive function
in AD by serving as an acetylcholine precursor.
13
The brain uses choline preferentially for acetyl-
choline synthesis, which can limit the amount of
choline available for phosphatidylcholine produc-
tion.
When the demand for acetylcholine in-
creases or choline stores in the brain are low, phos-
pholipids in the neuronal membrane may be
catabolized to supply the needed choline.
3
Exog-
enous citicoline may thus help preserve the struc-
tural and functional integrity of the neuronal mem-
brane.
In an in vitro study, citicoline at high con-
centrations stimulated brain acetylcholinesterase
(AChE), along with Na+/ K+-ATPase.
14
The pos-
tulated mechanism involves bioconversion of
citicoline to phosphatidylcholine in the external
leaflet of the neuronal membrane, the site of AChE
activity. Citicoline is not known to function as an
AChE inhibitor in humans, however. Thus, the
significance of this finding with regard to
citicoline’s therapeutic mechanisms in cognitive
disorders is unknown.
Neuronal Membrane Repair
Citicoline has been investigated as a
therapy for stroke patients. Three mechanisms are
postulated: (1) repair of the neuronal membrane
via increased synthesis of phosphatidylcholine; (2)
repair of damaged cholinergic neurons via
potentiation of acetylcholine production; and (3)
Page 20 Alternative Medicine Review
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Citicoline Review
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reduction of free fatty acid buildup at the site of
stroke-induced nerve damage.
3
Citicoline protects cholinergic neurons
from autocannibalism, a process in which mem-
brane phospholipids are catabolized to provide
choline for synthesis of acetylcholine. This occurs
when choline supplies are depleted, necessitating
sacrifice of membrane phospholipids to maintain
neurotransmission. As an exogenous source of
choline for acetylcholine production, citicoline
thus spares membrane phospholipids (in particu-
lar, phosphatidylcholine) and prevents neuronal
cell death.
15
In addition to phosphatidylcholine,
citicoline serves as an intermediate in the synthe-
sis of sphingomyelin, another neuronal membrane
phospholipid component. Citicoline has shown
ability to restore post-ischemic sphingomyelin lev-
els.
16
Sphingomyelin is formed from ceramide, a
lipid synthesized in the endoplasmic reticulum that
appears to function as an intracellular second mes-
senger and is a byproduct of an intramembranal
reaction between ceramide and phosphatidylcho-
line.
17
Citicoline also restores levels of cardio-
lipin, a phospholipid component of the inner mi-
tochondrial membrane. The mechanism for this is
unknown, but data suggest citicoline inhibits en-
zymatic hydrolysis of cardiolipin by phospholi-
pase A
2
. Citicoline inhibits release of arachidonic
acid, which serves as substrate for phospholipase
A
2
. The arachidonic acid content of phosphatidyl-
choline is decreased following post-ischemic
reperfusion due to hydrolysis of the phospholipid.
Because citicoline replenishes the arachidonic acid
content of phosphatidylcholine, it is suggested that
citicoline prevents activation of phospholipase A
2
,
rather than inhibiting its activity.
18
Recent inves-
tigative work has shown citicoline is not an in vivo
phospholipase A
2
inhibitor. In an animal study,
citicoline was found to decrease the formation of
hydroxyl radicals following ischemia and perfu-
sion, again suggesting citicoline acts to decrease
phospholipase stimulation.
19
Citicoline’s effect on phospholipase A
2
may account for the observation that citicoline
restores sphingomyelin levels after ischemia/
reperfusion, protecting hippocampal neurons in the
process.
15
Tumor necrosis factor, which is released
during ischemia, stimulates sphingomyelinase,
resulting in hydrolysis of sphingomyelin. Evidence
suggests that this process is mediated by the phos-
pholipase/arachidonic acid pathway.
20
Modulation
of phospholipase activity by citicoline and con-
comitant inhibition of sphingomyelinase could be
another route by which citicoline provides
neuroprotection.
Effect on beta-Amyloid
Evidence has surfaced that citicoline may
counteract the deposition of beta-amyloid, a neu-
rotoxic protein believed to play a central role in
the pathophysiology of AD. The characteristic le-
sion in AD is the formation of plaques and neu-
rofibrillary tangles in the hippocampus. The de-
gree of cognitive dysfunction and
neurodegeneration in AD is proportional to the
buildup of beta-amyloid.
21,22
Citicoline counter-
acted neuronal degeneration in the rat hippocam-
pus induced by intrahippocampal injection of beta-
amyloid protein. The number of apoptotic cells
was also reduced. Memory retention, as measured
by a passive-avoidance learning task, improved
in the rats.
23
In an in vitro study showing increases in
phospholipid levels of rat brain cells induced by
choline plus cytidine (citicoline components), ex-
cretion of amyloid precursor protein (APP) was
also stimulated. Found in the lipid bilayer of neu-
ronal membranes, APP contains a peptide that
forms amyloid deposits in Alzheimer’s patients.
This follows abnormal cleavage of APP that oc-
curs due to decreased phospholipid content (phos-
phatidylcholine and phosphatidylethanolamine)
with resulting destabilization of the cell mem-
brane. This formation of amyloidogenic APP frag-
ments is an abnormal occurrence that takes place
as a result of aging or neuron damage. Under nor-
mal conditions, APP is cleaved in such a way that
the amyloidogenic peptide is broken down, result-
ing in the extracellular secretion of nonplaque-
forming APP fragments. Because citicoline re-
stores membrane phospholipids, it may thus pro-
mote this normal cleavage process. Choline plus
Alternative Medicine Review
Volume 9, Number 1 2004 Page 21
Review Citicoline
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cytidine were found to stimulate secretion of in-
tact, neurotrophic APP from rat brain cells. These
findings suggest citicoline may promote neuronal
regeneration in Alzheimer’s patients.
24
Effect on Neurotransmitters
Citicoline increased brain levels of neu-
rotransmitters in rats at a dose of 100 mg/kg, ad-
ministered daily for seven days. Norepinephrine
increased in the cerebral cortex and hypothalamus,
dopamine increased in the corpus striatum, and
serotonin increased in the cerebral cortex, stria-
tum, and hypothalamus.
25
An earlier study found somewhat differ-
ent results. Intravenous administration of citicoline
to rats increased dopamine synthesis in the cor-
pus striatum; tyrosine levels also increased. The
authors suggested citicoline may stimulate tyrosine
hydroxylase activity, thus potentiating dopamine
synthesis. Norepinephrine levels increased slightly
in the cerebral cortex; no change was observed in
the brain stem. However, serotonin levels and rate
of synthesis in the midbrain and hypothalamus
decreased in this study. This effect was seen with
doses ranging from 10-100 mg/kg. Serotonin syn-
thesis in the cortex was unchanged. This effect of
activating dopamine while inhibiting serotonin is
suggested as a mechanistic explanation for the
reported anti-parkinsonism and central nervous
system (CNS) stimulation by citicoline.
26
Another investigation by the same re-
search team found citicoline inhibits synaptic
dopamine uptake in the corpus striatum of rats,
leading the researchers to propose this as a pos-
sible explanation for the therapeutic effect of
citicoline in Parkinson’s disease (see below).
27
Evidence of citicoline’s ability to enhance nore-
pinephrine release in humans was found in a study
showing that citicoline raised urinary levels of 3-
methoxy-4-hydroxyphenylglycol (MHPG), a
norepinephrine metabolite.
28
Rat studies have found evidence that
citicoline potentiates dopamine release in the
brain, presumably by stimulating release of ace-
tylcholine.
29
Animal Studies
Cerebro-protection
Citicoline injected experimentally into the
cerebrum of gerbils shortly before artificially-in-
duced ischemia has demonstrated an ability to
partially restore phosphatidylcholine levels while
inhibiting free fatty acid release, suggesting sta-
bilization of the neuronal membrane.
15
In another gerbil study, citicoline restored
ischemia-depleted levels of phosphatidylcholine,
sphingomyelin, and cardiolipin after one day of
reperfusion. In addition, this study found that af-
ter three days of reperfusion, citicoline increased
both glutathione levels and glutathione reductase
activity, suggesting citicoline may contribute to
reduction of oxidative stress.
30
Traumatic injury damages the brain in
numerous ways, including cell death due to edema,
disruption of the blood-brain barrier, ischemia, and
shear stress. Three underlying pathologies are
thought to be at work at the site of brain injury:
(1) breakdown of phospholipids in the cell mem-
brane, resulting in decreased phosphatidylcholine
content; (2) release of free fatty acids from the
degraded membrane, which causes local edema
due to accumulation of inflammatory arachidonic
acid metabolites such as prostaglandins and
leukotrienes; and (3) decreased release of acetyl-
choline, resulting in impaired cholinergic nerve
transmission.
The ability of citicoline to reverse the ef-
fects of brain injury has been tested in animal
models of cerebral ischemia. Administered intra-
peritoneally, citicoline was found to reduce brain
edema and decrease breakdown of the blood-brain
barrier in rats at a dose of 400 mg/kg.
31
Citicoline has been shown to delay brain
cell membrane damage and behavioral dysfunc-
tion in spontaneously hypertensive rats with is-
chemia caused by artificially-induced occlusion
of the lateral middle cerebral artery.
32
This effect
of citicoline was greatest in rats with mild cell
injury due to lack of oxygen.
In another similar study, citicoline was
tested in an animal stroke model. Temporary fo-
cal ischemia was artificially induced in rats via
blockage of the right middle cerebral artery and
Page 22 Alternative Medicine Review
Volume 9, Number 1 2004
Citicoline Review
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maintained for two hours. For the
next six days the animals were
treated with citicoline at doses of
100 or 500 mg/kg, or placebo. In
the rats administered the higher
citicoline dose, the “infarct vol-
umes” (volume of damaged brain
tissue at ischemia sites) were sig-
nificantly smaller than in the pla-
cebo group. Similar reductions in
the lower-dose group failed to
reach statistical significance.
Less brain edema was also ob-
served in the rats given
citicoline.
33
Citicoline appears to re-
verse neuronal membrane pa-
thology that occurs in cerebral is-
chemia. Depletion of ATP causes
cytidine 5’-monophosphate to
accumulate within the mem-
brane, which in turn increases
bioconversion of phosphatidyl-
choline to diacylglycerol and free
fatty acids (Figure 2). These
breakdown products can become
toxic to the membrane due to
excess levels of free radicals,
lipid peroxides, and arachidonic
acid and its metabolites such as
leukotrienes. The protective ef-
fect of citicoline against these
pathologies was demonstrated in
gerbils with artificially induced
forebrain ischemia.
4
The gerbils
were pretreated with either
citicoline or saline as control.
The animals were anesthetized,
the carotid arteries clamped to
induce ischemia, and then
reperfused for six days.
Citicoline provided partial pro-
tection against the damaging is-
chemic effects. Attenuated
arachidonic acid release, de-
creased blood-brain barrier dys-
function, less edema, and protection of neurons
Figure 2. Conversion of Diglycerides to
Phosphatidylcholine or Free Fatty Acids under Various
Conditions: Normal, Ischemia, and Exogenous
Citicoline
A. Normal
Phosphatidylcholine
+
Monoglycerides
Phosphatidylcholine
+
Monoglycerides
Phosphatidylcholine
+
Monoglycerides
B. Ischemia
C. Citicoline Treatment
Exogenous Citicoline
Diglycerides + Increased CDP-choline
Free Fatty Acids
From: Weiss GB. Metabolism and actions of CDP-choline as an
endogenous compound and administered exogenously as citicoline.
Life Sciences 1995;56:647.
Diglycerides
+
CDP-choline
Free Fatty Acids
Diglycerides
+
CDP-choline
Free Fatty Acids
Alternative Medicine Review
Volume 9, Number 1 2004 Page 23
Review Citicoline
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in the hippocampus were observed in the
citicoline-treated animals. Based on previous find-
ings of increased free radical production in hip-
pocampal neurons following reperfusion, it is theo-
rized citicoline inhibits oxygen free radical pro-
duction that accompanies arachidonic acid me-
tabolism.
In vitro studies using neuronal cultures
from chick embryos have shown that citicoline
may protect the hippocampus from injury. Addi-
tion of citicoline to the cultures both before and
after experimentally induced hippocampal injury
resulted in a protective effect.
34
Memory and Learning
Brain aging may be associated with de-
creased membrane phospholipid content, leading
to impaired membrane biofunction along with loss
of cholinergic neurons. Memory and cognition
depend on normal neuron-to-neuron communica-
tion via transmission of nerve impulses along the
neuronal membrane.
In one experiment citicoline was admin-
istered intraperitoneally to aged rats with cogni-
tive and motor impairment.
35
Using tests of active
and passive avoidance behavior, it was shown that
citicoline improved learning and memory capac-
ity. Motor performance also improved. Citicoline
also improved cognitive function in rats injected
with scopolamine, an amnesia-inducing anticho-
linergic drug, supporting the conclusion that
citicoline exerts cholinergic action.
35
The effects of citicoline on retention of
learned behavior in rats were observed in a series
of experiments.
36
Memory deficits were artificially
induced in young adult and aged rats via oxygen
deprivation (hypoxia), electric shock, and admin-
istration of scopolamine. Citicoline improved
memory performance in older but not younger rats,
which is consistent with the notion that citicoline
corrects impaired phospholipid metabolism.
Citicoline prevented amnesia induced by scopo-
lamine and by electric shock. Citicoline prevented
memory impairment in rats caused by sodium ni-
trate-induced hypoxia. Additional experiments
showed citicoline improved learning ability in rats
with fetal alcohol syndrome induced by feeding
alcohol to dams during pregnancy. The overall
conclusion drawn from these studies is that
citicoline improves memory only in animals with
measurable memory deficits.
Citicoline, however, has demonstrated the
ability to facilitate learning and memory in young,
normal dogs.
37
Ten one-year old dogs were put
through a series of operant conditioned-learning
experiments over a 42-day period. Compared to
control animals, dogs administered citicoline daily
prior to repetition of these procedures exhibited
superior memory processes including acquisition,
retention, and retrieval.
Citicoline as Adjunctive Therapy in
an Animal Model of Embolic Stroke
Citicoline has been tested in rats as a pos-
sible adjunct to thrombolytic therapy in embolic
stroke. In one experiment, embolism was artifi-
cially created in the carotid arteries of 83 Sprague-
Dawley rats.
38
The rats were then divided into six
treatment groups, including a saline-treated con-
trol group, using citicoline at two different doses
(250 mg/kg; 500 mg/kg) with or without the
antithrombotic agent – recombinant tissue plas-
minogen activator (rtPA). Size of the cerebral in-
farction caused by an embolism was significantly
reduced in the citicoline-plus-rtPA groups. Func-
tional recovery occurred in both the rats that re-
ceived citicoline plus rtPA and rats on citicoline
alone at the higher dose.
In another similar experiment, citicoline,
alone or in combination with the thrombolytic
agent urokinase, was injected into rats following
occlusion of the middle cerebral artery. This pro-
cedure causes focal ischemia and infarction in the
cerebral cortex. Saline-treated rats were used as
controls. Citicoline, injected as a single dose or
intermittently, significantly reduced neuronal dam-
age. Enhanced neuroprotection was seen in the rats
treated with citicoline plus urokinase.
39
Page 24 Alternative Medicine Review
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Citicoline Review
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Human Clinical Trials
Stroke Therapy
Citicoline has been tested on stroke pa-
tients in controlled trials. A multicenter, double-
blind, placebo-controlled trial evaluated the effect
of citicoline on 272 stroke patients in the acute
stage of moderate-to-severe cerebral infarction
with mild-to-moderate disturbances in conscious-
ness.
40
In the treatment group, 133 patients re-
ceived 1,000 mg citicoline by daily intravenous
administration for 14 days. Compared to the re-
maining 139 patients on placebo, the level of con-
sciousness improved significantly in the citicoline
group. By day 14, 54 percent of patients on
citicoline showed improvement, compared to 29
percent of placebo patients. The results suggest
intravenous citicoline promotes recovery from
reversible tissue damage in the acute stages of
stroke, while mitigating the aggravation of post-
stroke symptoms.
Other trials have administered citicoline
to post-stroke patients, demonstrating similar re-
sults to the above study, including enhancement
of recovery with improvements in parameters of
neurological function, such as muscle strength,
ambulation, and cognition. According to a recent
analysis of these trials, initiating citicoline within
the first 24 hours after stroke onset “increases the
probability of complete recovery at three
months.”
41
A multicenter, double-blind controlled
trial, conducted by the Citicoline Stroke Study
Group, examined the effects of oral citicoline on
259 stroke patients.
42
Three doses of citicoline (500
mg; 1,000 mg; or 2,000 mg) were administered to
three groups of 65 patients each, within 24 hours
of stroke onset, while a fourth group received pla-
cebo. Treatment was continued for six weeks, with
a six-week follow-up period. The primary clini-
cal endpoint was a change in the Barthel Index of
Neurological Function. The baseline NIH Stroke
Scale (NIHSS) score was assessed as a second
variable to decrease the effect of baseline differ-
ences in stroke severity. After 12 weeks, patients
in the groups receiving 500 mg or 2,000 mg
citicoline were found to have twice the chance of
stroke recovery compared to patients on placebo.
Curiously, no differences were seen between the
1,000-mg citicoline group and the placebo group.
No clear explanation was found for this apparent
anomaly, other than a difference in patient weight
in this group. Because the 2,000-mg group had a
higher incidence of dizziness and accidental in-
jury, the researchers concluded 500 mg per day
might be the optimum citicoline dose.
The Citicoline Stroke Study Group sub-
sequently conducted a second double-blind study
similar to the above trial.
43
This multicenter trial
enrolled 394 patients suffering from acute is-
chemic stroke, randomly assigning patients to the
treatment and placebo groups on a two-to-one
basis. Based on the previous results, 500 mg was
selected as the daily citicoline dose; the Barthel
Index and NIHSS score were used to assess effi-
cacy. No differences were found between the treat-
ment and placebo groups after six weeks of treat-
ment and follow-up. However, an inequality in
baseline stroke severity between treatment and
placebo groups was discovered; 34 percent of pa-
tients in the placebo group had had mild strokes
compared to 22 percent in the treatment group.
As reported, “This baseline imbalance may have
impacted the overall efficacy results in this trial.
The most recent investigative effort as-
sessing the effect of citicoline in acute ischemic
stroke was a double-blind, multicenter trial of 899
patients. The study enrolled patients with acute
ischemic stroke in the region of the middle cere-
bral artery. The subjects received either 2,000 mg
oral citicoline (1,000 mg twice daily) or placebo
for six weeks. A six-week, post-treatment follow-
up period then ensued. The primary study end-
point was the proportion of patients showing a
seven-point or greater improvement from baseline
in the NIHSS score. The outcome was virtually
the same for both groups: 52 percent of patients
in the citicoline group and 51 percent in the pla-
cebo group reached this level of improvement. The
researchers concluded: “Citicoline was safe but
ineffective in improving the outcome of patients
with acute ischemic stroke as measured by the
planned analyses.” The citicoline group did have
a significantly higher proportion of patients show-
ing improvement after six weeks, as measured by
Alternative Medicine Review
Volume 9, Number 1 2004 Page 25
Review Citicoline
Copyright©2004 Thorne Research, Inc. All Rights Reserved. No Reprint Without Written Permission
the Barthel Index, but this disappeared at the week-
12 analysis.
44
Cognition in the Elderly
Citicoline’s potential as a treatment for
memory impairment associated with aging was
studied in a 1989 double-blind trial of 84 elderly
patients with mild-to-moderate memory loss.
45
Based on the role of citicoline as an intermediate
of phosphatidylcholine biosynthesis, it was hy-
pothesized citicoline could reverse age-dependent
histopathological changes within the brain neu-
ronal membrane, thereby restoring memory func-
tion. The subjects, who all exhibited memory loss
as assessed by scores on the Mini Mental State
Examination (MMSE), took 1,000 mg citicoline
daily or placebo for six weeks. The Randt Memory
Test was administered after three weeks and at the
end of the treatment period. In addition to memory
factors such as immediate recall, delayed recall,
and global memory efficiency, the Randt test mea-
sures three cognitive function parameters: encod-
ing and organization (E-O), cognitive efficiency
(CE), and acquisition efficiency (AE). The results
showed AE improved while E-O and CE remained
unchanged. Because AE is specifically related to
attention, the researchers postulated this finding
evidenced a dopaminergic effect of citicoline,
based on an association between dopaminergic
stimulation and improvement in attention-related
cognitive mechanisms. Improvements in global
memory efficiency were also observed.
The effect of citicoline on verbal memory
in the elderly was tested in a double-blind trial
using 95 healthy volunteers ages 50-85.
46
This
study took place in two phases. In the initial phase,
all subjects took 1,000 mg citicoline or placebo
daily for three months. Analysis of the data re-
vealed a subgroup with relatively poor memory.
These subjects were recruited for the second cross-
over trial phase and given either placebo or 2,000
mg citicoline daily for three months. After the ini-
tial phase, improvement with citicoline occurred
only in the poor-memory subgroup, which showed
gains in delayed recall and logical memory. At the
end of the second phase, greater improvements
occurred in the citicoline group, suggesting that
2,000 mg per day is a more effective dose for age-
associated memory impairment.
In a double-blind, crossover trial,
citicoline was administered orally to 24 memory-
impaired elderly subjects for four weeks.
Citicoline was given alone at 500 or 1,000 mg
doses, or combined with nimodipine, a calcium
channel blocker used to treat neurological defi-
cits in brain hemorrhage patients (citicoline 300
mg/day plus nimodipine 90 mg/day). Pre- and
post-treatment memory performance was evalu-
ated. The results showed that citicoline improved
the ability to recall words and objects after view-
ing them for two seconds each. In tests of recog-
nition, where subjects attempt to identify previ-
ously viewed words and objects randomly mixed
with non-viewed items, no improvement was ob-
served. Positive results occurred in all three treat-
ment groups.
47
A recent meta-analysis looked at data from
published, double-blind, randomized human tri-
als on citicoline and cognitive impairment in pa-
tients with chronic cerebral disorders. It was con-
cluded that citicoline modestly improves memory
and behavioral outcomes.
48
Effect on Brain Wave Activity
Citicoline appears to reverse abnormali-
ties in brain electrical patterns that occur with ag-
ing. Age-related cognitive disorders are typically
associated with increases in the delta, theta, and
fast beta ranges, while the alpha and slow beta
frequencies decrease. In an uncontrolled study, 24
patients with “organic brain syndrome” (charac-
terized by symptoms such as disorientation, cog-
nitive impairment, and emotional lability in pa-
tients suffering from cerebrovascular or degenera-
tive brain disease) were administered intravenous
citicoline at a dose of 500 mg daily. As measured
by EEG, statistically significant increases in al-
pha frequencies were observed, along with de-
creases in delta frequencies. Insignificant reduc-
tions in theta and slow beta frequencies were also
seen; clinical parameters improved.
49
In another study analyzing changes in
brain mapping with citicoline administration, 19
Alzheimer’s disease patients received 100 mg oral
Page 26 Alternative Medicine Review
Volume 9, Number 1 2004
Citicoline Review
Copyright©2004 Thorne Research, Inc. All Rights Reserved. No Reprint Without Written Permission
citicoline daily for one month. Thirteen subjects
were early-onset (EOAD) Alzheimer’s patients;
the remaining six were late onset (LOAD). Theta
band decreases in the frontal-temporal region were
observed, along with frontal decreases of beta
bands. A moderate increase in the alpha frequency
was noted in the occipital regions of LOAD pa-
tients. No other changes occurred in the relative
power of other frequencies. Cerebral hemodynam-
ics also improved, measured by increases in blood
flow velocities. Immunological changes and
slightly reduced serum cytokine levels were ob-
served. EOAD patients, who are known to have
higher histamine levels than LOAD patients,
showed lowered histamine levels after one month
on citicoline.
50
Brain Injury
Brain injury results in depletion of cell
membrane phospholipids, followed by intracellu-
lar cerebral edema due to breakdown of the so-
dium-potassium pump.
51
In a single-blind, ran-
domized trial, 216 head injury patients were as-
signed to two treatment groups. One group re-
ceived conventional treatment as control while the
other received conventional treatment plus intra-
venous citicoline at a dose of 1,000 mg daily. The
proportion of patients showing improvements in
cognitive and motor symptoms was greater in the
citicoline group; there were no differences in death
rate between the two groups.
52
Other studies have shown citicoline facili-
tates memory rehabilitation in brain trauma pa-
tients by restoring blood flow to the lesion site.
53
In a small double-blind study, one month on 1,000
mg oral citicoline daily significantly improved the
ability to recall designs in patients with concus-
sion, as compared to placebo. There were no sig-
nificant differences between the two groups in
other tests of cognitive function, such as word or
location recall or verbal fluency. In the placebo
group, a greater trend toward complaints of post-
concussional symptoms such as headache, dizzi-
ness, and tinnitus was observed at follow-up.
54
Alzheimer’s Disease
Citicoline has demonstrated a possible
ability to improve cognitive performance in
EOAD. A 1994 double-blind study examined the
effect of one-month treatment with citicoline on
cognition in 20 Alzheimer’s patients. Following
citicoline treatment (1,000 mg/day orally), cogni-
tive function assessed using MMSE improved
slightly in an EOAD patient subgroup, as shown
by small, but statistically significant (p<0.005)
increases in MMSE scores. MMSE scores de-
creased in patients in later stages of the disease.
Spatial-temporal orientation improved in the to-
tal group, with a more marked difference in EOAD
patients.
55
A more recent double-blind, placebo-con-
trolled trial tested the effect of citicoline therapy
on 30 patients with mild-to-moderate senile de-
mentia of the Alzheimer’s type. Citicoline was
administered over a 12-week period at a daily dose
of 1,000 mg. The cognitive function subset of the
Alzheimer’s Disease Assessment Scale (ADAS)
and “clinical interview based impression of
change” (CIBIC) were utilized as primary outcome
measures, with additional subsets of the ADAS
and the MMSE used as secondary measurements.
The overall results showed differences between
the citicoline and placebo groups, but the changes
were only trends that did not reach statistical sig-
nificance. Non-significant improvements were
seen with citicoline in the ADAS-cognitive scores
and CIBIC scores.
56
Brain hemodynamics were assessed in the
above two trials. Citicoline was shown to slightly
increase cerebral blood flow and velocities, in
comparison with placebo. In the first trial this was
postulated as resulting from immunogenic or neu-
rotrophic mechanisms, since a direct vasoactive
effect was not observed. The mechanisms are con-
sistent with citicoline’s apparent role as a cholin-
ergic system potentiator, via acetylcholine biosyn-
thesis and activation of muscarinic receptors in
the central nervous system.
55
Based on a hypothetical autoimmune
component in the pathophysiology of AD, a study
was conducted to assess citicoline’s effect on im-
mune function in Alzheimer’s patients. Citicoline,
Alternative Medicine Review
Volume 9, Number 1 2004 Page 27
Review Citicoline
Copyright©2004 Thorne Research, Inc. All Rights Reserved. No Reprint Without Written Permission
at an oral dose of 1,000 mg daily, was adminis-
tered to three groups: EOAD patients, LOAD pa-
tients, and patients with multi-infarct dementia; a
fourth group served as control. Increased levels
of interleukin-1β were normalized after three
months on citicoline.
57
Other Therapeutic Effects
Glaucoma/Amblyopia
Results from two open trials suggest that
citicoline repairs damage to the optic nerve that
occurs in glaucoma.
58
Citicoline appears to pro-
vide neuroprotection to the retina by enhancing
phosphatidylcholine synthesis. Glaucoma, a lead-
ing cause of blindness in the elderly, is a
neurodegenerative disease characterized by
apoptosis of retinal ganglion cells. Damage to the
retina may occur before detectable vision loss.
59
In a short-term, double-blind, placebo-controlled
trial, citicoline administered by intramuscular in-
jection (1,000 mg/day) improved retinal and vi-
sual function in open-angle glaucoma patients.
60
It is postulated that dopaminergic stimulation is a
major mechanism for citicoline’s effect on the
retina.
58
This hypothesis is bolstered by a recent
animal study showing that citicoline raises the
retinal dopamine concentration in rabbits.
61
Citicoline, at a dose of 1,000 mg daily
administered by intramuscular injection was found
to significantly improve visual acuity in patients
with amblyopia.
62,63
Parkinson’s Disease
Based on citicoline’s hypothetical ability
to improve dopaminergic function, a double-blind
crossover trial was conducted on Parkinson’s dis-
ease patients who were undergoing treatment with
L-dopa plus a decarboxylase inhibitor. Improve-
ments in bradykinesia and rigidity were seen in
subjects administered citicoline (500 mg daily via
intramuscular injection) when compared to pla-
cebo subjects; tremor was unchanged.
64
Vascular Dementia
A small, double-blind clinical trial found
no effect of citicoline treatment in 30 patients age
55 or older with moderate-to-severe vascular de-
mentia (VaD). This study excluded patients with
AD, stroke, head injury, or other severe neurologi-
cal disorders. The diagnosis of VaD was based on
brain abnormalities measured by MRI, along with
a battery of neuropsychological tests assessing
cognitive and psychomotor function. Fifteen sub-
jects were administered a 500 mg citicoline tablet
twice daily, while 15 took placebo tablets. Out-
comes were assessed after six and 12 months. No
differences were found between treatment and pla-
cebo groups in neuropsychological performance
at baseline and at the study end. MRIs showed
exacerbation of brain pathology in both groups as
the study progressed.
65
Toxicology
The LD
50
of a single intravenous dose of
citicoline was 4,600 mg/kg and 4,150 mg/kg in
mice and rats, respectively. An oral LD
50
could
not be determined as no deaths occurred at the
maximum possible oral dose.
66
No toxic effects were observed in 30-day
subacute toxicity studies of oral citicoline to two
groups of rats at doses of 100 mg/kg and 150 mg/
kg. No changes occurred in blood chemistry, or-
gan histology, or urinary parameters.
67
The effect of chronic oral consumption of
citicoline was studied in dogs who were fed a
single 1.5 g/kg dose daily for six months. No toxic
effects were seen nor did any physiological, bio-
chemical, neurological, or morphological abnor-
malities occur.
68
Citicoline exhibits a very low toxicity pro-
file in humans. In a short-term, placebo-controlled,
crossover study, 12 healthy adults took citicoline,
at daily doses of 600 and 1,000 mg, or placebo for
consecutive five-day periods. Transient headaches
occurred in four subjects on the 600 mg dose, five
on the 1,000 mg dose, and one on placebo. No
changes or abnormalities were observed in hema-
tology, clinical biochemistry, or neurological
tests.
69
In an unpublished GLP acute toxicology
study, free-base citicoline was administered to
male and female rats at a dose of 2,000 mg/kg
body weight for 14 days. No changes in body
Page 28 Alternative Medicine Review
Volume 9, Number 1 2004
Citicoline Review
Copyright©2004 Thorne Research, Inc. All Rights Reserved. No Reprint Without Written Permission
weight, deaths, clinical symptoms or gross patho-
logical changes were observed. A GLP, sub-acute,
90-day toxicology study on free-base citicoline is
underway, with results slated for release in early
2004.
Clinical Safety
Citicoline has an excellent track record of
clinical safety. A large drug surveillance study
analyzed the results of citicoline treatment in 2,817
patients ages 60-80 suffering from senility and
cerebral vascular insufficiency. A total of 151 in-
cidents of side effects were recorded, represent-
ing five percent of the patient sample. The most
common adverse effects were transient in nature
and included stomach pain and diarrhea in 102
cases. Vascular symptoms of hypotension, tachy-
cardia, or bradycardia occurred in 16 cases.
70
Conclusion and Future Directions
Citicoline is a form of the B-vitamin cho-
line that serves as a choline donor and intermedi-
ate in the biosynthesis of phospholipids and ace-
tylcholine. Citicoline reduces ischemic injury in
the CNS by preserving membrane phospholipids,
chiefly phosphatidylcholine. As a therapeutic in-
tervention in acute stroke the studies have yielded
mixed results. It is possible exogenous citicoline
may increase the possibility of complete recovery
when treatment is started within 24 hours of stroke
onset. Citicoline therapy might improve cognitive
function in elderly patients with memory deficits,
mild cognitive impairment, and senile dementia
of the Alzheimer’s type. Citicoline exhibits a very
low toxicity profile, and appears to be safe for
long-term clinical use and consumption as a di-
etary supplement. A human clinical trial is soon
to begin that will assess the effect of free-base
citicoline on memory in 50-75 year-olds.
References
1. Secades JJ, Frontera G. CDP-choline: pharma-
cological and clinical review. Methods Find
Exp Clin Pharmacol 1995;17:1-54.
2. Weiss GB. Metabolism and actions of CDP-
choline as an endogenous compound and
administered exogenously as citicoline. Life
Sci 1995;56:637-660.
3. D’Orlando KJ, Sandage BW Jr. Citicoline
(CDP-choline): mechanisms of action and
effects in ischemic brain injury. Neurol Res
1995;17:281-284.
4. Rao AM, Hatcher JF, Dempsey RJ. CDP-
choline: neuroprotection in transient forebrain
ischemia of gerbils. J Neurosci Res
1999;58:697-705.
5. Dinsdale JR, Griffiths GK, Rowlands C, et al.
Pharmacokinetics of
14
C CDP-choline.
Arzneimittelforschung 1983;33:1066-1070.
6. Agut J, Font E, Sacrist·n A, Ortiz JA. Radioac-
tivity incorporation into different cerebral
phospholipids after oral administration of
14
C
methyl CDP-choline. Arzneimittelforschung
1983;33:1048-1050.
7. G-Coviella IL, Wurtman RJ. Enhancement by
cytidine of membrane phospholipid synthesis.
J Neurochem 1992;59:338-343.
8. Lopez-Coviella I, Agut J, Savci V, et al.
Evidence that 5’-cytidinediphosphocholine can
affect brain phospholipid composition by
increasing choline and cytidine plasma levels.
J Neurochem 1995;65:889-894.
9. Gimenez R, Soler S, Aguilar J. Cytidine
diphosphate choline administration activates
brain cytidine triphosphate: phosphocholine
cytidylyltransferase in aged rats. Neurosci Lett
1999;273:163-166.
10. Babb SM, Appelmans KE, Renshaw PF, et al.
Differential effect of CDP-choline on brain
cytosolic choline levels in younger and older
subjects as measured by proton magnetic
resonance spectroscopy. Psychopharmacology
(Berl) 1996;127:88-94.
11. Babb SM, Wald LL, Cohen BM, et al. Chronic
citicoline increases phosphodiesters in the
brains of healthy older subjects: an in vivo
phosphorus magnetic resonance spectroscopy
study. Psychopharmacology (Berl)
2002;161:248-254.
12. de la Morena E. Efficacy of CDP-choline in
the treatment of senile alterations in memory.
Ann N Y Acad Sci 1991;640:233-236.
13. Amenta F, Di Tullio MA, Tomassoni D. The
cholinergic approach for the treatment of
vascular dementia: evidence from pre-clinical
and clinical studies. Clin Exp Hypertens
2002;24:697-713.
Alternative Medicine Review
Volume 9, Number 1 2004 Page 29
Review Citicoline
Copyright©2004 Thorne Research, Inc. All Rights Reserved. No Reprint Without Written Permission
14. Plataras C, Tsakiris S, Angelogianni P. Effect
of CDP-choline on brain acetylcholinesterase
and Na(+), K(+)-ATPase in adult rats. Clin
Biochem 2000;33:351-357.
15. Adibhatla RM, Hatcher JF, Dempsey RJ.
Citicoline: neuroprotective mechanisms in
cerebral ischemia. J Neurochem 2002;80:12-
23.
16. Adibhatla RM, Hatcher JF. Citicoline mecha-
nisms and clinical efficacy in cerebral is-
chemia. J Neurosci Res 2002;70:133-139.
17. Mayes PA. Metabolism of acylglycerols and
sphingolipids. In: Murray RK, Mayes PA, eds.
Harper’s Biochemistry. 25
th
ed. Norwalk, CT:
Appleton & Lange; 2000.
18. Rao AM, Hatcher JF, Dempsey RJ. Does CDP-
choline modulate phospholipase activities after
transient forebrain ischemia? Brain Res
2001;893:268-272.
19. Adibhatla RM, Hatcher JF. Citicoline de-
creases phospholipase A2 stimulation and
hydroxyl radical generation in transient
cerebral ischemia. J Neurosci Res
2003;73:308-315.
20. Jayadev S, Linardic CM, Hannun YA. Identifi-
cation of arachidonic acid as a mediator of
sphingomyelin hydrolysis in response to tumor
necrosis factor alpha. J Biol Chem
1994;269:5757-5763.
21. Nitta A, Itoh A, Hasegawa T, Nabeshima T.
Beta-amyloid protein-induced Alzheimer’s
disease animal model. Neurosci Lett
1994;170:63-66.
22. Nitta A, Fukuta T, Hasegawa T, Nabeshima T.
Continuous infusion of beta-amyloid protein
into the rat cerebral ventricle induces learning
impairment and neuronal and morphological
degeneration. Jpn J Pharmacol 1997;73:51-57.
23. Alvarez XA, Sampedro C, Lozano R,
Cacabelos R. Citicoline protects hippocampal
neurons against apoptosis induced by brain
beta-amyloid deposits plus cerebral
hypoperfusion in rats. Methods Find Exp Clin
Pharmacol 1999;21:535-540.
24. Wang CS, Lee RK. Choline plus cytidine
stimulate phospholipid production, and the
expression and secretion of amyloid precursor
protein in rat PC12 cells. Neurosci Lett
2000;283:25-28.
25. Petkov VD, Stancheva SL, Tocuschieva L,
Petkov VV. Changes in brain biogenic
monoamines induced by the nootropic drugs
adafenoxate and meclofenoxate and by
citicholine (experiments on rats). Gen
Pharmacol 1990;21:71-75.
26. Martinet M, Fonlupt P, Pacheco H. Effects of
cytidine-5’ diphosphocholine on norepineph-
rine, dopamine and serotonin synthesis in
various regions of the rat brain. Arch Int
Pharmacodyn Ther 1979;239:52-61.
27. Martinet M, Fonlupt P, Pacheco H. Interaction
of CDP-choline with synaptosomal transport
of biogenic amines and their precursors in vitro
and in vivo in the rat corpus striatum.
Experientia 1978;34:1197-1199.
28. Lopez I, Coviella G, Agut J, Wurtman RJ.
Effect of cytidine(5’)diphosphocholine (CDP-
choline) on the total urinary excretion of 3-
methoxy-4-hydroxyphenylglycol (MHPG) by
rats and humans. J Neural Transm
1986;66:129-134.
29. Agut J, Coviella IL, Wurtman RJ.
Cytidine(5’)diphosphocholine enhances the
ability of haloperidol to increase dopamine
metabolites in the striatum of the rat and to
diminish stereotyped behavior induced by
apomorphine. Neuropharmacology
1984;23:1403-1406.
30. Adibhatla RM, Hatcher JF, Dempsey RJ.
Effects of citicoline on phospholipid and
glutathione levels in transient cerebral is-
chemia. Stroke 2001;32:2376-2381.
31. Baskaya MK, Dogan A, Rao AM, Dempsey
RJ. Neuroprotective effects of citicoline on
brain edema and blood-brain barrier break-
down after traumatic brain injury. J Neurosurg
2000;92:448-452.
32. Aronowski J, Strong R, Grotta JC. Citicoline
for treatment of experimental focal ischemia:
histologic and behavioral outcome. Neurol Res
1996;18:570-574.
33. Schabitz WR, Weber J, Takano K, et al. The
effects of prolonged treatment with citicoline
in temporary experimental focal ischemia. J
Neurol Sci 1996;138:21-25.
34. Mykita S, Golly F, Dreyfus H, et al. Effect of
CDP-choline on hypocapnic neurons in
culture. J Neurochem 1986;47:223-231.
35. Drago F, Mauceri F, Nardo L, et al. Effects of
cytidine-diphosphocholine on acetylcholine-
mediated behaviors in the rat. Brain Res Bull
1993;31:485-489.
Page 30 Alternative Medicine Review
Volume 9, Number 1 2004
Citicoline Review
Copyright©2004 Thorne Research, Inc. All Rights Reserved. No Reprint Without Written Permission
36. Petkov VD, Kehayov RA, Mosharrof AH, et
al. Effects of cytidine diphosphate choline on
rats with memory deficits.
Arzneimittelforschung 1993;43:822-828.
37. Bruhwyler J, Liegeois JF, Geczy J. Facilitatory
effects of chronically administered citicoline
on learning and memory processes in the dog.
Prog Neuropsychopharmacol Biol Psychiatry
1998;22:115-128.
38. Andersen M, Overgaard K, Meden P, et al.
Effects of citicoline combined with throm-
bolytic therapy in a rat embolic stroke model.
Stroke 1999;30:1464-1471.
39. Shuaib A, Yang Y, Li Q. Evaluating the
efficacy of citicoline in embolic ischemic
stroke in rats: neuroprotective effects when
used alone or in combination with urokinase.
Exp Neurol 2000;161:733-739.
40. Tazaki Y, Sakai F, Otomo E, et al. Treatment of
acute cerebral infarction with a choline
precursor in a multicenter double-blind
placebo-controlled study. Stroke 1988;19:211-
216.
41. Davalos A, Castillo J, Alvarez-Sabin J, et al.
Oral citicoline in acute ischemic stroke: an
individual patient data pooling analysis of
clinical trials. Stroke 2002;33:2850-2857.
42. Clark WM, Warach SJ, Pettigrew LC, et al. A
randomized dose-response trial of citicoline in
acute ischemic stroke patients. Citicoline
Stroke Study Group. Neurology 1997;49:671-
678.
43. Clark WM, Williams BJ, Selzer KA, et al. A
randomized efficacy trial of citicoline in
patients with acute ischemic stroke. Stroke
1999;30:2592-2597.
44. Clark WM, Wechsler LR, Sabounjian LA,
Schwiderski UE; Citicoline Stroke Study
Group. A phase III randomized efficacy trial of
2000 mg citicoline in acute ischemic stroke
patients. Neurology 2001;57:1595-1602.
45. Agnoli A, Bruno G, Fioravanti M, et al.
Therapeutic approach to senile memory
impairment: a double-blind clinical trial with
CDP choline. In: Wurtman RJ, Corkin S,
Growden JH, eds. Alzheimer’s Disease:
Proceedings of the Fifth Meeting of the
International Study Group on the Pharmacol-
ogy of Memory Disorders Associated with
Aging. Boston, MA: Birkhauser; 1989:649-
654.
46. Spiers PA, Myers D, Hochanadel GS, et al.
Citicoline improves verbal memory in aging.
Arch Neurol 1996;53:441-448.
47. Alvarez XA, Laredo M, Corzo D, et al.
Citicoline improves memory performance in
elderly subjects. Methods Find Exp Clin
Pharmacol 1997;19:201-210.
48. Fioravanti M, Yanagi M.
Cytidinediphosphocholine (CDP choline) for
cognitive and behavioral disturbances associ-
ated with chronic cerebral disorders in the
elderly (Cochrane Review) In: The Cochrane
Library. Oxford, England: Update Software;
2002:4.
49. Franceschi M, Smirne S, Canal N. Treatment
of clinical signs and EEG patterns in patients
with “organic brain syndrome.Clin Trials J
1982;19:74-84.
50. Cacabelos R, Caamano J, Gomez MJ, et al.
Therapeutic effects of CDP-choline in
Alzheimer’s disease. Ann N Y Acad Sci
1996;777:399-403.
51. Gannushkina IV. Pathogenesis of traumatic
brain edema. In: Mchedlishvili G, et al, eds.
Brain Edema, A Pathogenic Analysis.
Budapest: Akademiai Kiado; 1986:290-292.
52. Maldonado VC, Perez JB, Escario JA. Effects
of CDP-choline on the recovery of patients
with head injury. J Neurol Sci 1991;103:S15-
S18.
53. Leon-Carrion J, Dominguez-Roldan JM,
Murillo-Cabezas F, et al. The role of citicoline
in neuropsychological training after traumatic
brain injury. NeuroRehabilitation 2000;14:33-
40.
54. Levin HS. Treatment of postconcussional
symptoms with CDP-choline. J Neurol Sci
1991;103:S39-S42.
55. CaamaÒo J, GÛmez MJ, Franco A, Cacabelos
R. Effects of CDP-choline on cognition and
cerebral hemodynamics in patients with
Alzheimer’s disease. Methods Find Exp Clin
Pharmacol 1994;16:211-218.
56. Alvarez XA, Mouzo R, Pichel V, et al. Double-
blind placebo-controlled study with citicoline
in APOE genotyped Alzheimer’s disease
patients. Effects on cognitive performance,
brain bioelectrical activity and cerebral
perfusion. Methods Find Exp Clin Pharmacol
1999;21:633-644.
57. Cacabelos R, Alvarez XA, Franco-Maside A,
et al. Effect of CDP-choline on cognition and
immune function in Alzheimer’s disease and
multi-infarct dementia. Ann N Y Acad Sci
1993;695:321-323.
Alternative Medicine Review
Volume 9, Number 1 2004 Page 31
Review Citicoline
Copyright©2004 Thorne Research, Inc. All Rights Reserved. No Reprint Without Written Permission
58. Grieb P, Rejdak R. Pharmacodynamics of
citicoline relevant to the treatment of glau-
coma. J Neurosci Res 2002;67:143-148.
59. Quigley HA, Addicks EM, Green WR. Optic
nerve damage in human glaucoma: III.
Quantitative correlation of nerve fiber loss and
visual field defect in glaucoma, ischemic
neuropathy, papilledema, and toxic neuropa-
thy. Arch Opthalmol 1982;100:135-146.
60. Parisi V, Manni G, Colacino G, Bucci MG.
Cytidine-5’-diphosphocholine (citicoline)
improves retinal and cortical responses in
patients with glaucoma. Ophthalmology
1999;106:1126-1134.
61. Rejdak R, Toczolowski J, Solski J, et al.
Citicoline treatment increases retinal dopamine
content in rabbits. Ophthalmic Res
2002;34:146-149.
62. Campos EC, Schiavi C, Benedetti P, et al.
Effect of citicoline on visual acuity in amblyo-
pia: preliminary results. Graefes Arch Clin Exp
Ophthalmol 1995;233:307-312.
63. Porciatti V, Schiavi C, Benedetti P, et al.
Cytidine-5’-diphosphocholine improves visual
acuity, contrast sensitivity and visually-evoked
potentials of amblyopic subjects. Curr Eye Res
1998;17:141-148.
64. Agnoli A, Ruggieri S, Denaro A, Bruno G.
New strategies in the management of
Parkinson’s disease: a biological approach
using a phospholipid precursor (CDP-choline).
Neuropsychobiology 1982;8:289-296.
65. Cohen RA, Browndyke JN, Moser DJ, et al.
Long-term citicoline (cytidine diphosphate
choline) use in patients with vascular demen-
tia: neuroimaging and neuropsychological
outcomes. Cerebrovasc Dis 2003;16:199-204.
66. Grau T, Romero A, Sacristan A, Ortiz JA.
CDP-choline: acute toxicity study.
Arzneimittelforschung 1983;33:1033-1034.
67. Romero A, Grau T, Sacristan A, Ortiz JA.
Study of subacute toxicity of CDP-choline
after 30 days of oral administration to rats.
Arzneimittelforschung 1983;33:1035-1038.
68. Romero A, Grau T, Sacristan A, Ortiz JA.
CDP-choline: 6-month study on toxicity in
dogs. Arzneimittelforschung 1983;33:1038-
1042.
69. Dinsdale JR, Griffiths GK, Castello J, et al.
CDP-choline: repeated oral dose tolerance
studies in adult healthy volunteers.
Arzneimittelforschung 1983;33:1061-1065.
70. Lozano Fernandez R. Efficacy and safety of
oral CDP-choline. Drug surveillance study in
2817 cases. Arzneimittelforschung
1983;33:1073-1080.
... Further, CT demonstrates a positive neurotherapeutic influence in the contexts of hypoxia, ischemia, and enhanced learning and memory function in animal brain aging models [46]. CT is a part of the cluster of biomolecules in living organizations termed "nucleotides", showing significant functions in cell metabolism [ 48 ] . ...
... CT contains ribose, pyrophosphate, a nitrogenous base (cytosine), and choline [46]. Combined with B vitamins, choline represents a trim ethylated nitrogenous base, passing in three main pathways of The first one is phospholipid synthesis by phosphorylcholine; the second is acetylcholine synthesis, and the third is oxidation to betaine that assists as a methyl giver [48]. The construction of endogenously CT considers the ratelimiting stage in synthesizing phosphatidylcholine (the major membrane phospholipid) from choline [48]. ...
... Combined with B vitamins, choline represents a trim ethylated nitrogenous base, passing in three main pathways of The first one is phospholipid synthesis by phosphorylcholine; the second is acetylcholine synthesis, and the third is oxidation to betaine that assists as a methyl giver [48]. The construction of endogenously CT considers the ratelimiting stage in synthesizing phosphatidylcholine (the major membrane phospholipid) from choline [48]. Exogenous CT, which is the form analyzed in the intestine and freely consumed as a form of choline and cytidine, penetrates numerous biosynthetic pathways, which operate CT as an intermediate. ...
... щемозговыми симптомами (снижение уровня сознания, головная боль, тошнота, рвота, менингеальные знаки) в различных сочетаниях. Однако, острые нарушения мозгового кровообращения в 25-90% случаев сопровождаются различными психическими расстройствами, влияющими на медицинскую, социально-бытовую и трудовую реабилитацию так же, а иногда и более негативно, чем неврологический дефицит, и служат неблагоприятным прогностическим признаком [6,12,13]. ...
... вительном периоде около 80% случаев психических расстройств представлены симптомами непсихотического уровня [3,4], которые как по поведенческим, так и по патофизиологическим механизмам снижают комплаентность больных, препятствуют проведению полноценной реабилитации и могут ухудшать прогноз пациента [6,9,12]. ...
... В настоящее время активно обсуждается использование принципиально новых групп препаратов, воздействующих на патогенетические механизмы развития постинсультных психических расстройств и позволяющих предотвратить их негативное влияние на прогноз и реабилитацию [10,11,12]. Так препараты, содержащие Омега-3полиненасыщенные жирные кислоты, по отдельности эффективно используются для лечения большого эпизода депрессии [15] и профилактики церебрального инсульта [14]. ...
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The purpose of the study: to clarify the prevalence of non-psychotic mental disorders in the population of patients suffered a cerebral stroke, and to assess the potential use of neurotropic drugs for the correction of certain types of psychopathological syndromes. Materials and methods: 180 patients were examined in the recovery period of brain stroke (the average duration of stroke was 20.7±6.6 months): 78 men and 102 women aged 39 to 90 years (the average age was 64.8±11.2). All patients underwent neuroimaging, experimental psychological research and a psychiatrist’s examination. Results: as a result of the survey, almost all patients in the recovery period of a brain stroke (90.5%) were found non-psychotic mental disorders with a predominance of psychoasthenic syndrome and mnestic-intellectual disorders that develop because of the predomimamt lesion of the brain frontal lobes. As a result of isolated neurotropic therapy, several therapeutic tasks were solved: treatment of focal neurological deficit, reduction of asthenia and the severity of mnestico-intellectual disorders, reduced drug load on the patient. Conclusion: the majority of patients in the recovery period of stroke have various psychopathological disorders, but due to somatic burden can not always receive psychotropic therapy. In this case, it is important to use new approaches to the correction of psychopathological disorders. The use of isolated neurotropic therapy has shown high efficiency in correcting the psychopathological component of stroke, which allows solving several rehabilitation tasks. Research on various aspects of post-stroke mental disorders can help identify additional opportunities for personalized and safe treatment of patients who have suffered acute stroke.
... Citicoline can attenuate the increase in PLA2 activity by being a source of choline to prevent hydrolysis of phospholipids when internal choline levels are depleted. It also helps to stimulate the repair and regeneration of damaged mitochondria membranes by preserving sphingomyelin and cardiolipin levels [149,[175][176][177]183,184]. Citicoline also shows both potential to be anti-inflammation plus anti-viral on the UPS mechanism since it functions as a proteasome regulator by shifting the population in favor of capped proteasome particles, activates the intrinsic activity of the 20S and 19S to form the 26s particle, and it plays a modulatory role through a fine tuning between activation and limitation of its activity [24][25][26]69,70,[154][155][156]. ...
... Ci tenuate the increase in PLA2 activity by being a source of choline to preven phospholipids when internal choline levels are depleted. It also helps to st pair and regeneration of damaged mitochondria membranes by preservin lin and cardiolipin levels [149,[175][176][177]183,184]. Citicoline also shows both anti-inflammation plus anti-viral on the UPS mechanism since it funct In addition to its potential effects towards anti-inflammation along with its neuroprotective and neurorestorative properties toward COVID-19, citicoline has been known to positively affect neuronal network capability in cognitive domains ranging from working memory, episodic memory, empirical method, attention, to processing of spatial memory; and it also influences cellular physiology on hippocampal and brain cortex neurons [189]. ...
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With growing concerns about COVID-19’s hyperinflammatory condition and its potentially damaging impact on the neurovascular system, there is a need to consider potential treatment options for managing short- and long-term effects on neurological complications, especially cognitive function. While maintaining adequate structure and function of phospholipid in brain cells, citicoline, identical to the natural metabolite phospholipid phosphatidylcholine precursor, can contribute to a variety of neurological diseases and hypothetically toward post-COVID-19 cognitive effects. In this review, we comprehensively describe in detail the potential citicoline mechanisms as adjunctive therapy and prevention of COVID-19-related cognitive decline and other neurologic complications through citicoline properties of anti-inflammation, anti-viral, neuroprotection, neurorestorative, and acetylcholine neurotransmitter synthesis, and provide a recommendation for future clinical trials.
... Most of the choline from food intake and endogenous production is converted into PC, which accounts for 95% of the total choline pool in most animal tissues [61]. When choline content is insufficient, the CNS choline is preferentially used for the synthesis of acetylcholine, which is used in cholinergic neurotransmission, and that process may restrict the production of phosphatidylcholine [62]. In addition, the body converts PC to choline through the PEMT/phospholipase reactions, thus compensating for choline content [63]. ...
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The anxiety and depression caused by inflammatory bowel diseases (IBD) are known to greatly affect the mental health of patients. The mechanism of psychiatric disorders caused by IBD is not fully understood. Previous research has suggested that the gut microbiome plays a key role in IBD. Curcumin is a yellow polyphenol extracted from the rhizome of the ginger plant, which has been shown to have effects against both depression and anxiety. Research has indicated that curcumin affects the gut microbiome and exerts antianxiety and neuroprotective effects through the microbiota-gut-brain axis (MGB). However, whether curcumin can alleviate the psychiatric disorders caused by IBD and how curcumin affects the MGB axis through the gut microbiota have not been fully understood. Therefore, this study was aimed at determining the metabolic parameters and microbiological environment in the peripheral and central nervous system to determine the effects of curcumin against anxiety induced by dextran sulfate sodium salt (DSS) in mice. To elaborate on the link between the gut microbiota and how curcumin alleviates anxiety-like behaviors, we performed a fecal microbiota transplantation (FMT) experiment. The results suggested that curcumin can effectively relieve anxiety-like behaviors caused by DSS in mice. Further, curcumin treatment can alleviate disturbances in the gut microbiota and systemic disorders of lipid metabolism caused by DSS. Finally, through FMT, we verified that curcumin increased phosphatidylcholine in the prefrontal cortex of the mice and alleviated DSS-induced anxiety-like behaviors by modulating specific gut microbiota. We also revealed that Muribaculaceae may be a key part of the gut microbiota for curcumin to alleviate DSS-induced anxiety-like behaviors through the MGB axis.
... As a consequence, memory, concentration, and perception dysfunctions occur. The patient loses contact with their environment, is delusional, irritable, and aggressive (40,41). In pharmacotherapy, drugs improving the cognitive functions are used, which inhibit the clinical course and facilitate the functioning of the patient. ...
... On the other hand, cytidine diphosphate choline )citicoline) is known to be a memory and learning enhancer in aging, and brain degenerative diseases. [13][14][15] An intermediate product, cytidine diphosphate-choline generates phosphatidylcholine from choline. 16 Citicoline appears to stimulate cell membrane stabilization by phospholipid biosynthesis; as a result, it boosts memory and learning. ...
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Introduction: Motor learning consolidates in adulthood, and its defects begin to appear with aging. Ghrelin, an endogenous peptide, improves memory and learning, targeting dopaminergic circuits. While cytidine diphosphate choline (citicoline) is known as a common drug for enhancing memory and learning in aging, it is not recommended for adults due to its side effects. The current study aimed at investigating if ghrelin treatment would improve motor learning via the expression of a relevant gene. Methods: For this experimental study, adult male Wistar rats were randomly divided into five groups: control group, three groups of ghrelin treatment (0.3, 1.5, and 3 nmol/μL), and one group with citicoline treatment. The injections were done intra-hippocampally. The motor learning rate was determined using the rotarod performance test by measuring the resistance to falling. Then the expression of dopamine receptor type D1 (Drd1) gene in the hippocampus was measured by a real-time polymerase chain reaction (PCR). Results: Ghrelin (3 nmol/μL) and citicoline had similar and significant effects on motor learning improvement (P<0.01). Both drugs significantly increased Drd1 gene expression (P <0.001). Conclusion: Ghrelin, like citicoline, improves motor learning by altering the expression of Drd1 gene in the hippocampus.
... Previous studies mainly focused on the diseases of atrial fibrillation (AF), 16 hypertension, 17 and stoke. 18 The inconclusive results may not translate to clinical practice because the physicians could be using these medicines cautiously. Given the limitations of previous studies, our study will evaluate the pooled associations of all CVD medicines and MCFI and dementia in people with CVD conditions. ...
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Objective: The objective of this review is to investigate the association between the use of cardiovascular medicines and the risk of mild cognitive function impairment and dementia in people with cardiovascular disease. Introduction: Cardiovascular disease is one of the most important modifiable factors for mild cognitive function impairment and dementia. The current evidence about the effectiveness of cardiovascular disease medicine on the risk of dementia is inconclusive; hence, it is imperative to conduct a comprehensive investigation on the effect of cardiovascular disease medicine on the risk of mild cognitive function impairment and dementia. Inclusion criteria: This review will include studies involving participants (age ≥18 years) who were using cardiovascular medicine for hypertension, myocardial infarction, atrial fibrillation, stroke, or heart failure. The eligible studies will include observational studies and randomized controlled trials. Methods: MEDLINE (Ovid), Embase (Ovid), and PsycINFO (Ovid) will be searched from 2000 to the present. We will only include studies published in English. Title, abstracts, and full texts will be screened by authors independently. The methodological quality of included studies will be assessed using the JBI critical appraisal checklist for observational studies and randomized controlled trials. The data to be extracted will include the basic study characteristics, populations, drug groups, clinical indicators, and outcomes. Studies will be pooled using statistical meta-analysis, where possible. Alternatively, the findings will be presented in narrative form where statistical pooling is not possible. Systematic review registration number: PROSPERO CRD42020175386.
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(1) Backgrond: Considering the positive effects of citicoline (CIT) in the management of some neurodegenerative diseases, the aim of this work was to develop CIT-Loaded Solid Lipid Nanoparticles (CIT-SLNs) for enhancing the therapeutic use of CIT in parkinsonian syndrome; (2) Methods: CIT-SLNs were prepared by the melt homogenization method using the self-emulsifying lipid Gelucire® 50/13 as lipid matrix. Solid-state features on CIT-SLNs were obtained with FT-IR, thermal analysis (DSC) and X-ray powder diffraction (XRPD) studies. (3) Results: CIT-SLNs showed a mean diameter of 201 nm, −2.20 mV as zeta potential and a high percentage of entrapped CIT. DSC and XRPD analyses evidenced a greater amorphous state of CIT in CIT-SLNs. On confocal microscopy, fluorescent SLNs replacing unlabeled CIT-SLNs released the dye selectively in the cytoplasm. Biological evaluation showed that pre-treatment of SH-SY5Y dopaminergic cells with CIT-SLNs (50 µM) before the addition of 40 µM 6-hydroxydopamine (6-OHDA) to mimic Parkinson’s disease’s degenerative pathways counteracts the cytotoxic effects induced by the neurotoxin, increasing cell viability with the consistent maintenance of both nuclear and cell morphology. In contrast, pre-treatment with CIT 50 and 60 µM or plain SLNs for 2 h followed by 6-OHDA (40 µM) did not significantly influence cell viability. (4) Conclusions: These data suggest an enhanced protection exerted by CIT-SLNs with respect to free CIT and prompt further investigation of possible molecular mechanisms that underlie this difference.
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To gain insights into the influence of heat stress on lipid metabolism in juvenile turbot (Scophthalmus maximus), we analyzed the correlations between data obtained by transcriptome sequencing and metabolome sequencing of the kidney under different high temperature stimuli (20 °C, 25 °C and 28 °C) and control conditions (14 °C). We identified the differentially expressed genes and metabolites, which were found to be enriched in seven pathways (steroid hormone biosynthesis, primary bile acid biosynthesis, glycerophospholipid metabolism, linoleic acid metabolism, sphingolipid metabolism, glycerolipid metabolism and biosynthesis of unsaturated fatty acids) associated with lipid metabolism, according to KEGG pathway analysis. After correlation analysis of these differentially expressed genes, the most representative genes (lpcat2, Etnk1, TAZ, SCP2, ch25hl and gpd1l) and metabolites (citicoline, UPD-6-sulfoquinovose, dihydroxyacetone, taurine and o-phosphocholine) were selected according to their correlation coefficients. These genes and metabolites were found to be the key points to regulate lipid deposition and maintain lipid homeostasis through varying degrees of up-regulation or down-regulation under heat stress, so as to relieve the disorder of lipid metabolism caused by heat stress, which is of great significance for breeding new heat-resistant varieties of turbot and provides a reliable theoretical basis for optimizing actual production. These results provide new clues for understanding the roles of lipid metabolism in fish under heat stress.
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Potential therapeutic effects of cytidine 5-diphosphocholine (citicoline), a key intermediary in the biosynthesis of the membrane phospholipid, phosphatidylcholine, are presumably related to enhanced phospholipid synthesis in the ischemic brain. We evaluated prolonged citicoline treatment in a temporary focal ischemia model. Using the suture occlusion model, we induced 2 hours of temporary ischemia in 30 Sprague-Dawley rats. The rats were randomly and blindly assigned to receive intraperitoneally 500 mg/kg citicoline (HD), 100 mg/kg citicoline (LD) or physiologic saline as the control group once daily for 7 days (n = 10 per group) beginning at the time of reperfusion. Neurological scoring (0–5 scale) was performed daily. After elective sacrifice on day 7, or earlier if death occured prematurely, the brains underwent 2,3,5-triphenyltetrazolium chloride (TTC) staining for calculation of corrected infarct and edema volume.The mean corrected infarct volume in the HD group was 125 ± 45.2 mm3 (mean ± SD), significantly smaller than controls, 243.5 ± 88.6 mm3 (p < 0.01, Scheffe's-test). The LD group infarct volume was 200.2 ± 62.8 mm3 (N.S.). The mean amount of brain edema in the HD group was 46.4 ± 45.6 mm3 was smaller than the controls, 92.3 ± 54.4 mm3 and the LD group, 84.9 ± 71.7 mm3 (N.S.). Mortality before day 7 in the HD was 30% while it was 50% in the two other groups. The neurologic score on day 7 was 2.5 ± 1.8 in the HD group, 3.3 ± 1.8 in the LD group and 3.4 ± 1.7 in controls (N.S.).These results demonstrate that extended high dose citicoline treatment significantly reduced infarct volume in this temporary focal ischemia model and that there was a trend toward reducing brain edema and mortality. These effects may be related to membrane stabilization and inhibition of free fatty acid release.
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Cytidine-5'-diphosphocholine (CDP-choline) therapy is currently used to improve the consciousness level in patients with brain lesions and as a complement to levodopa therapy in Parkinson's disease. Recently, the substance has been shown to improve the visual acuity (VA) of both eyes of adults with amblyopia. This study aims at establishing whether Contrast Sensitivity (CS) and visually-evoked potentials (VEPs) also change after CDP-choline treatment. VA, CS, and VEPs were measured in a group of amblyopic volunteers (n = 10, mean age 24.8 years) before treatment with Neuroton (CDP-choline, 1 g/day intramuscularly [IM] for 15 days) and the day after termination of the same. CS was evaluated, using a forced-choice, automatic procedure (QUEST: Watson and Pelli, 1983). Steady-state VEPs were recorded in response to counterphased (8 Hz) sinusoidal gratings (2 c/deg) of different contrasts. On average, after treatment, VA improved 1.4-1.5 lines in the amblyopic eyes and 0.4 lines in the normal eyes. CSs improved in both dominant and amblyopic eyes by about 3 dB. VEPs increased in amplitude (about 30%) and advanced in phase (about 0.2 pi rad). Amplitude and phase changes were not correlated. Treating adult amblyopes with CDP-choline has the effect of improving their VA, CS and VEPs. Changes occur in both eyes, although to different extents, and resemble those previously reported for levodopa treatment.
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The effects of acute and chronic administration of citicholine (Brassel) on the EEG spectral analysis and clinical features of patients with organic brain syndrome have been evaluated in patients with "organic brain syndrome.". The chronic citicholine treatment induced EEG modification, mainly, a significant increase in the power of the alpha frequency and a significant reduction of the delta power. An evident improvement was obtained in the behavioural rating scales and in the quantitative tests of the attentive concentration levels. After acute administration there was a significant reduction of the delta frequencies, possibly induced by an improvement of vigilance.
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To investigate the toxicity of beta-amyloid protein, a component of the senile plaques in Alzheimer's disease, it was infused into the cerebral ventricle of rats for 14 days by a mini-osmotic pump. Performances in the water maze and passive avoidance tasks in beta-amyloid protein-treated rats were impaired. Choline acetyltransferase activity significantly decreased in the hippocampus both immediately and 2 weeks after the cessation of the infusion. However, the learning impairment was recoverable 2 weeks after cessation of the infusion. Both immediately and 2 weeks after the cessation of the infusion, glial fibrillary acidic protein immunoreactivity increased. Furthermore, beta-amyloid protein altered the staining in the nuclei of hippocampal cells for only 2 weeks after the cessation. These results suggest that beta-amyloid protein produces some damage in the central nervous system in vivo.
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We examined the effects of orally administered 5′-cytidinediphosphocholine (CDP-choline) on arterial plasma choline and cytidine levels and on brain phospholipid composition in rats. Animals receiving a single oral dose of 100, 250, or 500 mg/kg showed peak plasma choline levels 6–8 h after drug administration (from 12 ± 1 to 17 ± 2, 19 ± 2, and 24 ± 2 µM, respectively). The area under the plasma choline curve at >14 µM, i.e., at a concentration that induces a net influx of choline into the brain, was significantly correlated with CDP-choline dose. In rats receiving 500 mg/kg this area was 2.3 times that of animals consuming 250 mg/kg, which in turn was 1.8 times that of rats receiving 100 mg/kg. Plasma cytidine concentrations increased 5.4, 6.5, and 15.1 times baseline levels, respectively, 8 h after each of the three doses. When the oral CDP-choline treatment was prolonged for 42 and 90 days, brain phosphatidylcholine concentrations increased significantly (by 22–25%; p < 0.05) in rats consuming 500 mg/kg/day. Brain phosphatidylethanolamine and phosphatidylserine concentrations also increased significantly under some experimental conditions; levels of other phospholipids were unchanged.
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Cytidine, as cytidine 5′-diphosphate choline, is a major precursor in the synthesis of phosphatidylcholine in cell membranes. In the present study, we examined the relationships between extracellular levels of cytidine, the conversion of [14C]choline to [14C]phosphatidylcholine, and the net syntheses of phosphatidylcholine and phosphatidyleth-anolamine by PC12 cells. The rate at which cytidine (as [3H]cytidine) was incorporated into the PC12 cells followed normal Michaelis-Menten kinetics (Km= 5 μM; Vmax= 12 × 10−3 mmol/mg of protein/min) when the cytidine concentrations in the medium were below 50 μM; at higher concentrations, intracellular [3H]cytidine nucleotide levels increased linearly. Once inside the cell, cytidine was converted mainly into cytidine triphosphate. In pulse-chase experiments, addition of cytidine to the medium caused a time- and dose-dependent increase (by up to 30%) in the incorporation of [14C]choline into membrane [14C]-phosphatidylcholine. When the PC12 cells were supplemented with both cytidine and choline for 14 h, small but significant elevations (p > 0.05) were observed in their absolute contents of membrane phosphatidylcholine, phospha-tidylethanolamine, and phosphatidylserine, all increasing by 10–15% relative to their levels in cells incubated with choline alone. Exogenous cytidine, acting via cytidine triphosphate, can thus affect the synthesis and levels of cell membrane phospholipids.
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The phosphatidylcholine precursor, cytidine-diphosphocholine (CDP-choline), was injected intraperitoneally (IP) at the dose of 10 or 20 mg/kg/day for 20 days to 24-month-old male rats of the Sprague-Dawley strain that showed cognitive and motor deficits. The drug was also injected in animals with behavioral alterations induced pharmacologically with a single injection of the cholinergic receptor antagonist, scopolamine, with prenatal exposure to methylazoxymethanol (MAM rats), or with bilateral injections of kainic acid into the nucleus basalis magnocellularis (NBM). Learning and memory capacity of the animals, studied with tests of active and passive avoidance behavior, was improved after treatment with CDP-choline in all experimental groups. An improvement in motor performance and coordination in the rotorod and open field tests was also observed in aged rats. These results indicate that this drug affects central mechanisms involved in cognitive behaviors, probably through a cholinergic action.
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1. Citicoline (cytidine (5') diphosphocholine) has been shown to reverse aging-induced memory deficits, scopolamine-induced amnesia and nucleus basalis magnocellularis lesion-induced learning impairment. 2. This study aimed to evaluate the effects of citicoline on learning and retrieval processes in a complex differential reinforcement of response duration schedule in normal dogs. 3. The effects of citicoline on a stabilized performance were also measured in order to be able to differentiate specific memory effects from non specific influences on the motor, neuro-vegetative and motivational systems. 4. The results demonstrate that citicoline can exert facilitatory effects on learning and memory but also on retrieval processes. The complete absence of effects on the stabilized performance and on the motor, neuro-vegetative and motivational systems constitutes arguments in favour of a selectivity of action on the memory processes.