Evaluation of Oxidative Stress in Patients with Acute Ischemic Stroke

3 Oxidative stress in acute ischemic stroke ORIGINAL ARTICLES 97
Evaluation of Oxidative Stress in Patients with Acute Ischemic Stroke
INIMIOARA MIHAELA COJOCARU 1,3 , M. COJOCARU 2 ,
VIOLETA ŞAPIRA 3 , ANDREEA IONESCU 3
1 “Carol Davila” University of Medicine and Pharmacy, Bucharest
2 “Titu Maiorescu” University, Faculty of Medicine, Bucharest
3“Colentina” Clinical Hospital, Department of Neurology, Bucharest, Romania
Oxidative stress is involved in the pathogenesis of acute ischemic stroke. Antioxidants are
consumed in the reaction with free radicals generated during the oxidative stress. The aim of the study
was the to evaluate the oxidative stress in patients with acute ischemic stroke. Malondialdehyde
(MDA), plasma glutathione, plasma glutathione peroxidase (GPX), catalase (CAT), uric acid,
bilirubin, plasma superoxide dismutase (SOD), red blood cells superoxide dismutase (RBS SOD)
(spectrophotometric assay), total antioxidant capacity (TAC) (enhanced chemiluminescence),
ceruloplasmin, C-reactive protein (CRP), albumin, transferrin (nephelometric assay) were performed
in 57 patients (mean age 73.4±6.5 years) with acute ischemic stroke within 24 hours and at 7 days
after stroke onset as compared to 51 age-and sex-matched controls. Significantly lower values in the
first 24 hours were: plasma glutathione, CAT, plasma SOD, RBS SOD (p < 0.001), plasma GPX,
TAC, transferrin (p < 0.05). Significantly higher values in the first 24 hours were: CRP (p < 0.001),
MDA, uric acid (p < 0.05). Significantly lower values at 7 days were: TAC, albumin, transferrin (p <
0.001), plasma glutathione, plasma SOD, CAT (p < 0.05). Significantly higher values at 7 days were:
MDA, plasma GPX, RBC SOD, CRP, uric acid, bilirubin (p < 0.001), ceruloplasmin (p
150 µmol/L, gout or renal failure or taking of
antioxidant vitamins.
ANOVA test (repeated measures analyses of
variance) was used to test within and between
subject differences and p < 0.05 was considered
significant.
RESULTS
Forty of the stroke patients had large vessel
disease and 17 had lacunar infarcts.
Mean value of MDA was in patients with
stroke within 24 hours 2.36 ± 0.22 nmol/mL, at
7 days 3.14 ± 0.36 nmol/mL and in controls 1.32 ±
0.11 nmol/mL (p < 0.05, respectively p < 0.001)
(Fig. 1).
ROM. J. INTERN. MED., 2013, 51, 2, 97–106

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Mean value of plasma glutathione was in
patients with stroke within 24 hours 0.17 ±
0.03 µmol/L, at 7 days 0.22 ± 0.04 µmol/L and in
controls 0.38 ± 0.07 µmol/L (p

3 Oxidative stress in acute ischemic stroke 99
p < 0.001 p < 0.05
Fig. 2. Mean value of plasma glutathione in patients with acute ischemic stroke within 24 hours,
at 7 days, and in controls.
p < 0.05 p < 0.001
Fig. 3. Mean value of plasma glutathione peroxidase (GPX) in patients with acute ischemic stroke within 24 hours,
at 7 days, and in controls.
p < 0.001 p < 0.05
Fig. 4. Mean value of catalase (CAT) in patients with acute ischemic stroke within 24 hours,
at 7 days, and in controls.

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p < 0.05 p < 0.001
Fig. 5. Mean value of uric acid in patients with acute ischemic stroke within 24 hours, at 7 days, and in controls.
p < 0.05 p < 0.001
Fig. 6. Mean value of bilirubin in patients with acute ischemic stroke within 24 hours, at 7 days, and in controls.
p < 0.001 p < 0.05
Fig. 7. Mean value of plasma superoxide dismutase (SOD) in patients with acute ischemic stroke within 24 hours,
at 7 days, and in controls.

5 Oxidative stress in acute ischemic stroke 101
p < 0.001 p < 0.001
Fig. 8. Mean value of red blood cells superoxide dismutase (RBC SOD) in patients
with acute ischemic stroke within 24 hours, at 7 days, and in controls.
p < 0.001 p < 0.001
Fig. 9. Mean value of total antioxidant capacity (TAC) in patients with acute ischemic stroke
within 24 hours, at 7 days, and in controls.
p < 0.05 p < 0.05
Fig. 10. Mean value of ceruloplasmin in patients with acute ischemic stroke within 24 hours, at 7 days, and in controls.

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p < 0.001 p < 0.001
Fig. 11. Mean value of C-reactive protein (CRP) in patients with acute ischemic stroke within 24 hours,
at 7 days, and in controls.
p < 0.001 p < 0.001
Fig. 12. Mean value of albumin in patients with acute ischemic stroke within 24 hours, at 7 days, and in controls.
p < 0.001 p < 0.001
Fig. 13. Mean value of transferrin in patients with acute ischemic stroke within 24 hours,
at 7 days, and in controls.

7 Oxidative stress in acute ischemic stroke 103
DISCUSSION
Oxidative stress is an inbalance between
oxidants and antioxidants in favor of the oxidants,
potentially leading to damage. It has been proposed
that antioxidant changes reflect an altered redox
balance in several pathological states; antioxidants
would be consumed in the reaction with free
radicals.
The increased production of free radicals in
the setting of cerebral ischemia, with or without
reperfusion, can arise from several mechanisms:
glutamate stimulation of NMDA receptors, mitochondrial
dysfunction, activation of neuronal nitric
oxide synthase, induction of nitric oxide synthetase
or cyclooxygenase 2, autooxidation of catecholamines,
metabolism of free fatty acids, particularly arachidonic
acid, released during ischemia, migration of
neutrophils and leukocytes able to generate superoxide
anions, the conversion of xanthine dehydrogenase
to xanthine oxidase [2–19].
Lipid peroxidation, with accumulation of
both conjugated dienes and thiobarbiturate-reactive
material, is consistently found when cerebral ischemia
is followed by reperfusion. Hydroxyl radicals
(formed from hydrogen peroxide), peroxinitrite and
superoxide are powerful radicals that can cause
lipid peroxidation, a self propagating chain reaction,
that irreversibly damages plasma and mitochondrial
membranes. Malondialdehyde product of lipid
peroxidation, irreversibly disrupts enzymes, receptors
and membrane transport mechanisms. The concentrations
of MDA were significantly increased in
stroke patients, arising from excess free radical
activity [20–24].
Uric acid is a powerful free radical scavenger
in humans and these antioxidant properties could
be expected to offer a number of benefits within the
cardiovascular system. No potential biological
mechanisms are known by which raised UA concentrations
could influence the development of
stroke. Therefore, it is unclear whether high UA
concentrations promote or protect against the
development of cardio-vascular disease, or significant
as a possible marker of increased risk.
There is some evidence that increased
oxidative stress is associated with high circulating
uric acid levels and that uric acid may protect
against oxidative modification of endothelial enzymes
and preserves the ability of endothelium to mediate
vascular dilatation in the face of oxidative stress.
Following cerebral ischemia and reperfusion,
the metabolism of nucleosides and purine bases to
inosine and hypoxanthine via the xanthine oxidase
pathway, results in production of oxygen free
radicals. Xanthine oxidase is an enzyme that controls
the formation of uric acid.
Uric acid is the most abundant aqueus
antioxidant in humans, and contributes as much as
two-thirds of all free radical scavenging capacity in
the plasma. It is particularly effective in quenching
hydroxyl, superoxide and peroxynitrite, and may
serve a protective physiological role by preserving
lipid peroxidation [25–43].
A number of components present in the serum
have been shown to possess chain breaking antioxidant
capacity including albumin and bilirubin.
Enhanced total antioxidant capacity (TAC)
after acute stroke may protect against the adverse
effects of free radicals production during ischemia
and reperfusion. The TAC of biological fluids is
believed to be a useful measure of the ability of
antioxidant present in the fluids to protect against
oxidative damage to membranes and other cellular
components [44–46].
Both serum SOD and RBC SOD levels were
lower in acute stroke patients. It is possible that the
lower activity in the acute phase of stroke is a
consequence of a higher oxidative damage [47–53].
Mean serum levels of nonenzymatic antioxidants
and antioxidant enzyme activities were
lower in patients than in controls.
Our study revealed that almost all antioxidants
are reduced within 24 hours after an
ischemic stroke and increase over the following
days, suggesting the presence of a condition of
oxidative stress in this disease [54–55].
CONCLUSION
These results indicate that oxidative stress is
increased in acute ischemic stroke and that the
majority of antioxidants are reduced, which
suggests the possibility of therapeutic intervention
with antioxidant agents.
Stresul oxidativ este implicat în patogenia stroke-ului ischemic acut.
Antioxidanţii sunt consumaţi în reacţia cu radicalii liberi generaţi în cursul
stresului oxidativ. Scopul studiului a fost evaluarea stresului oxidativ la pacienţii

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cu stroke ischemic acut. Au fost investigate malondialdehida (MDA), glutationul
plasmatic, glutation peroxidaza plasmatică (GPX), catalaza (CAT), acidul uric,
bilirubina, superoxid dismutaza plasmatică (SOD), superoxid dismutaza eritrocitară
(RBS SOD) (colorimetrie), capacitatea antioxidantă totală (TAC) (chemiluminescenţă),
ceruloplasmina, proteina C-reactivă (CRP), albumina, transferina
(nefelometrie) la 57 pacienţi (vârsta medie 73,4 ± 6,5 ani) cu stroke ischemic acut în
primele 24 ore şi la 7 zile de la debutul stroke-ului comparativ cu un lot martor de
51 subiecţi cu vârste şi sex comparabile. Au prezentat valori semnificativ reduse în
primele 24 ore: glutationul plasmatic, catalaza (CAT), superoxid dismutaza plasmatică
(SOD), superoxid dismutaza eritrocitară (RBS SOD), (p

9 Oxidative stress in acute ischemic stroke 105
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Received April 20, 2013