Neuro-amelioration of cinnamaldehyde in aluminum-induced Alzheimer’s disease rat model

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Neuro-amelioration of cinnamaldehyde in
aluminum-induced Alzheimer’s disease rat model
Hesham N. Mustafa
To cite this article: Hesham N. Mustafa (2019): Neuro-amelioration of cinnamaldehyde in
aluminum-induced Alzheimer’s disease rat model, Journal of Histotechnology
To link to this article: https://doi.org/10.1080/01478885.2019.1652994
Published online: 28 Aug 2019.
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Neuro-amelioration of cinnamaldehyde in aluminum-induced Alzheimer’s
disease rat model
Hesham N. Mustafa
Anatomy Department, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
ABSTRACT
Aluminum (Al) is a neurotoxic substance which has played an important role in the etiology,
pathogenesis, and development of amyloid-β (Aβ) plaques. This study was carried out to evaluate
the neuroprotective effect of aqueous cinnamon extract against aluminum chloride (AlCl3)-
induced Alzheimer’s disease. Forty adult male albino rats, randomly divided into four equal
groups. Control group; ACE200 group administered aqueous cinnamon extract (ACE) orally;
AlCl3 group received daily intraperitoneal (i.p.) injection of AlCl3 for 60 days to induce neurotoxi-
city and AlCl3 + ACE200 group received a combination of AlCl3 and ACE in the same dose and
route as previous groups. Aluminum administration significantly enhanced the memory impair-
ment and the Aβ formation in the rat model. The cerebellum exhibited a significant reduced
number of Purkinje cells, marked decrease in the density of dendritic arborization and prominent
perineuronal spaces in the molecular layer. There was loss of dendritic spines, neurofibrillary
degeneration, and appearance of neuritic plaques. Concomitant administration of AlCl3 and ACE
displayed an observable protection against these changes with progressive improvement in
memory and intellectual performance. In conclusion, ACE may play a protective role against
formation of amyloid-β plaques in cerebellum.
KEYWORDS
Alzheimer; aluminum
chloride; cinnamon;
memory; amyloid beta;
apoptosis
Introduction
Aluminum (Al) is a neurotoxin that leads to develop-
ment of anxiety disorders, depression, memory deficits,
and symptoms similar to those for Alzheimer′s disease
(AD) [1]. Aluminum accumulates in the body through
medical interventions such as renal dialysis, vaccines,
antiperspirants, and allergy desensitization injections
[2]. Bondy reported that Al can induce programmed
cell death, vacuolar spaces, distortion in the architec-
ture and loss of Purkinje cell layer of cerebellar cor-
tex [3].
In addition, amyloid-β (Aβ) oxidative stress has
a critical role in Aβ-mediated neuronal cytotoxicity
by triggering neurodegeneration in AD [4]. Oxidative
damage and excessive reactive oxygen species (ROS)
production are initiated during earlier stages of AD
and induce mild cognitive impairment [5].
Additionally, oxidative damage has been associated
with mitochondrial membrane damage, dysfunction,
and lipid peroxidation elevation that plays
a significant role in the pathogenesis of brain disorders
induced by Al [6].
Astrocytes are vital for the optimal physiological
functions and existence of neurons as these are the
most plentiful glial cell type in the nervous system
[7–9]. Glial fibrillary acidic protein (GFAP) is the
chief intermediate filament protein of mature astro-
cytes and is known as the astrocyte-specific marker
responsible for controlling astrocyte movement and
shape; thus, GFAP has the crucial role in modulating
synaptic efficiency [9,10].
Aqueous (aq) cinnamon extract (ACE) has been
associated with a variety of beneficial effects. The
antioxidant properties are attributed to cinnamalde-
hyde and polymeric polyphenol molecules known as
proanthocyanidins [11]. These molecules have
inhibited amyloid fibril formation by interacting
with the polyphenols and Aβ [12,13] and through
a high binding affinity of proanthocyanidins to
unstructured proteins rich in proline [14]. The aq.
cinnamon extract effectively inhibited aggregation
of tau related to AD, and this inhibitory activity
was attributed to both a proanthocyanidin trimer
and cinnamaldehyde [13]. Studies showed that the
potentially toxic compounds in cinnamon bark were
found in lipid-soluble fractions, while low levels of
these compounds were in a water-soluble extract
[15] that is considered safer for uptake.
CONTACT Hesham N. Mustafa hesham977@hotmail.com Anatomy Department, Faculty of Medicine, King Abdulaziz University, JEDDAH 21589,
Saudi Arabia
JOURNAL OF HISTOTECHNOLOGY
https://doi.org/10.1080/01478885.2019.1652994
© 2019 National Society for Histotechnology

Therefore, the aim of this study was to clarify the
protective effect of aq. cinnamon extract on aluminum
neurotoxicity model for AD on the behavior changes
and cerebellar pathology in rats.
Material and methods
Ethical approval
This study was conducted after approval by the
Medical Research Ethics Committee of the Faculty of
Medicine, King Abdulaziz University [Reference No
220–19].
Animals
Forty male adult Wistar rats (6 wk of age) weighing
200 ± 20 g were obtained from the university Animal
House and were distributed randomly into four
groups of animals (n = 10). The rats were individually
housed in stainless steel cages at controlled tempera-
ture (22 ± 2°C) and humidity (55 ± 10%) for a 12/12
h cycle of light/dark with access to food and drinking
water ad libitum. The experimental procedures were
carried out in accordance with the international
guidelines for the care and use of animals in the
laboratory.
Chemicals
Aluminum chloride (AlCl3) (Cat No 8010810500;
MilliporeSigma, St Louis, MO, USA).
Preparation of cinnamon extract
Cinnamomum cassia obtained from local spice market
at Jeddah, Saudi Arabia and ground into a powder then
50 g of cinnamon powder was dissolved in 500 ml of
distilled water (dH2O) and boiled for 3 h. This mixture
was concentrated to make an oily extract using a rotary
evaporator (EYELA, Rotary Vacuum Evaporator,
N-1000 series, Tokyo Rikakikai Co., Ltd., Chuo-ku,
Tokyo, Japan) and lyophilized to obtain 12.48 g of
cinnamon powder [16].
Experimental design
Control group received dH2O through oral gavage.
ACE200 group were administered 200 mg/kg b. w./
day aq cinnamon extract (ACE) orally for 60 days
[11,14] and the selected dose was based on toxicity
studies carried out in our laboratory. AlCl3 group was
given 100 mg/kg b.w. intraperitoneally (i.p.) for 60 days
according to a previously reported dose that caused
neurotoxicity [17–19]. AlCl3 exposure was chosen
according to European Food Safety Authority that
recommended the aluminum mean occupational expo-
sure of adult humans (0.2–1.5 mg/kg-week) [20]. The
combination AlCl3 and ACE200 group received the
same doses and routes as the separate AlCl3 group
and ACE200 group.
Rewarded T-maze test
The neurocognitive function was evaluated by the
rewarded T-maze test for rats as described by Deacon
and Rawlins [21]. Before the experiment, the rat is
trained where it is allowed to explore the whole maze
and rewarded with food at completion of the test. The
rats were denied food for 24 h but allowed to have
water. At the start of the test, the rat is placed in the
start location, and the time in second which the rat
spends to reach the end of each arm was recorded
using an auto stopwatch. The test was done within 4
days of training rats to perform. All groups were sub-
jected to the rewarded T-maze test which was done:
Trial 1 was at zero time before starting, Trial 2 was 24
h after AlCl3 and Trial 3 was 24 h after the last dose of
the drugs for all groups [22].
Measurement of aluminum level in cerebella
The whole cerebella of randomly chosen rats (n = 4)
from each group were carefully separated, removed and
washed by ice-cold (4ºC) normal saline, weighed and
put into a solution containing 0.05 ml nitric acid
(1004551000, MilliporeSigma, St. Louis, MO, USA)
and 0.2 ml hydrogen peroxide (H2O2) (386790,
MilliporeSigma), then whole tissue mixture was incu-
bated at 120°C for 2 h. The aluminum level in cerebella
measured by µg/g was determined by an atomic
absorption spectrophotometer (PinAAcle500, Perkin
Elmer, Waltham, MA, USA) [23,24].
Cerebellum histology
At the end of the experiment, the remaining animals
were euthanized. The cerebellum surgically removed,
weighed, and fixed in 10% neutral buffered formalin
(NBF) for 24 h. Tissues were processed through an
ascending ethyl alcohol gradient (50%, 70%, 90%, and
95%) 30 min each for, 100% ethyl alcohol for 1
h (two changes), cleared in xylene for 1 h (two
changes), infiltrated with paraffin at 60°C for 2
h and embedded in paraffin. Sections 5 µm thick
were cut using a rotatory microtome (Shandon,
2 H. N. MUSTAFA

Finesse 325, ThermoFisher Scientific, Luton,
England), and mounted on slides precoated with an
egg albumin–glycerol adhesive. Sections were depar-
affinized in xylene (three changes, 15 min each) and
rehydrated through a descending alcohol gradient
(100%, 90%, 70%) 5–10 min each change to diH20.
Sections were stained 10 min in Harris hematoxylin
(HHS16, MilliporeSigma,), washed in tap H2O to
‘blue’ the nuclei, counterstained in Alcoholic Eosin
Y (515, 3,801,615; Leica Biosystems Inc., Buffalo
Grove, IL, USA) for 5 min., dehydrated through an
ascending alcohol gradient, cleared in xylene, and
coverslipped using Canada balsam (C1795,
MilliporeSigma) [10].
Congo red stain for the amyloid β
Sections were deparaffinized and rehydrated as pre-
viously described, and stained in Congo red solution
(1% Congo red in dH2O) (C-6277, MilliporeSigma) for
30–60 min, then rinse in distilled water. Differentiated
(5–10 dips) in alkaline alcohol solution (1% sodium
hydroxide + 50% alcohol). Then counterstained in hema-
toxylin (23–750016, MilliporeSigma) for 30 sec, blued in
ammonia water for 30 sec, rinsed in tap H2O for 5 min,
dehydrated through 95% and 100% alcohols, cleared in
xylene and cover glass mounted with resinous mounting
medium [6,7].
Bielschowsky silver stain for amyloid plaques
Bielshowsky silver stain can be used for diagnosis of AD.
Sections were deparaffinized and rehydrated as described
above. Slides are placed in pre-warmed (40ºC) silver
nitrate (AgNO3) solution (0.1 mol Titrisol, 109990,
MilliporeSigma) for 15 min until sections become
a brown color then washed in diH2O 3 times. The ammo-
niacal silver stain solution (AgNO3/NH4OH) was pre-
pared as follows: conc. ammonium hydroxide (NH4OH,
221228, MilliporeSigma), is added to the AgNO3 solution
drop by drop until the precipitate formed just turns clear.
Slides were returned to the AgNO3/NH4OH solution for
30 min in 40ºC oven followed by direct immersion into
the developer solution for about 1 min. The developer is
made with 20 ml of 40% formaldehyde (818708,
MilliporeSigma), 100 ml dH2O, 20 µl conc. nitric acid
(1004551000, MilliporeSigma), and 0.5 g citric acid
(sodium citrate, S4641, MilliporeSigma). Slides were
dipped for 1 min in 1% NH4OH to stop the silver reac-
tion, washed in dH2O 3 times, and placed in 5% aq.
sodium thiosulfate for 5 min. Sections were dehydrated,
cleared, and coverslipped [7].
Immunohistochemical (IHC) study
Immunostaining for glial fibrillary acidic protein
(GFAP) in the astrocytes was done on deparaffinized
sections after antigen retrieval and removal of endo-
genous peroxidase as done by Saleh et al. [7]. The
Histostain-Plus IHC Kit, HRP, broad spectrum
(859,043, Invitrogen, Carlsbad CA, USA) with diami-
nobenzidene (DAB) chromogen was used according to
kit instructions. The primary antibody was Anti-GFAP
(Anti-glial fibrillary acidic protein, mouse monoclonal,
IgG, clone GA5, MAB3402, RRID: AB_94844
MilliporeSigma) diluted 1:1000 and incubated over-
night at 4°C. The negative control was sectioned from
dH2O control group with PBS replacing the anti-GFAP
antibody. GFAP-positive (GFAP+) astrocytes will dis-
play brown cellular membranes and cytoplasm with
blue nuclei [7,9].
Quantitative morphometric study
Sections from all groups were examined using an
Olympus BX53 microscope fitted with a DP73 cam-
era (Olympus, Tokyo, Japan). Ten slides of non-
overlapping fields from each group with one slide
from each animal were analyzed with Image-Pro
Plus v6 (Media Cybernetics Inc., Bethesda, MD,
USA). For each rat in all groups, the number of
Purkinje cells were counted from 10 lobules in each
cerebellar section at 200x magnification. The average
value of Purkinje cells was calculated for these 10
lobules per section. The total length of the cerebellar
folia in the 10 lobules was estimated in µm then
converted into millimeter (mm). Purkinje cells =
mean value of cell number ÷ length (mm) of the
cerebellar folia according to McGoey et. al [25].
Also, the area percent for GFAP expressed in astro-
cytes and in their processes in cerebellar cortices
were measured.
Statistical analysis
Quantitative data were expressed as the mean and
standard deviations of different parameters (transit
time spent in the T-maze test, linear density of
Purkinje cells/mm length of the folia and area percent
of GFAP+ astrocytes) between the treated groups. Data
were analyzed using a one-way analysis of variance
(ANOVA) followed by a least significant difference
(LSD) post hoc test. All statistical analyses were imple-
mented using the Statistical Package for the Social
Sciences (SPSS), version 23. The values were consid-
ered significant when p < 0.05.
JOURNAL OF HISTOTECHNOLOGY 3

Results
T-maze test
The results demonstrated a significant increase in time
(seconds) taken by rats in the AlCl3 group to reach the
food in the T-maze indicating a deteriorated neurocogni-
tive function. Whereas the AlCl3 + ACE200 group showed
a significant decrease in time taken by rats to reach food in
the T-Maze indicating improved cognitive abilities as com-
pared to the AlCl3 group. Additionally, the ACE200 group
showed a significant decrease in time to achieve the task, as
compared to the control group (Table 1).
Data are presented as mean ± SE (n = 10). Mean with
different superscripts (a, b, c, d, e) are significant at p ≤
0.05. Trial 1 was at zero time before starting, Trial 2 was
24 h after AlCl3 and Trial 3 was 24 h after the last dose for
all groups. T-maze transit time is in sec.
Aluminum level in cerebella
AlCl3 levels in cerebella were detected by atomic absorp-
tion spectrophotometry. Results showed that AlCl3 treat-
ment had a significantly elevated Al level as compared to
control group. Otherwise, ACE200 administration inhib-
ited the increase of Al level (Figure 1, Table 2).
Each value represents the mean ± S.D.; P1
: compared
to control, P2:
compared to ACE200, P3:
compared to
AlCl3.
Cerebellar histology
Cell alteration and disintegration were compared to con-
trol. Neurons were morphologically damaged and showed
shrunken pyknotic hyperchromatic nuclei in AlCl3 group.
In AlCl3 + ACE200 group, the extent of neuronal damage
was declined significantly. Also, Cellular morphology was
improved and no sign of degeneration was observed as
compared to controls (Figure 2).
In AlCl3 group, Congo red staining results demon-
strated that noticeable amyloid β plaques were distributed
in the molecular layer and rare amyloid plaques were seen
in the granular layer. Amyloid plaques exhibited a light
red mass without distinct borders. In AlCl3 + ACE200
group, the positively stained areas of amyloid plaques
were markedly reduced with a normal, restored appear-
ance and numbers of Purkinje cell layer (Figure 3).
Immunohistochemical results
AlCl3 group showed many GFAP+
hypertrophic astro-
cytes with extensive branching of processes extending
into the molecular cell layer. In the AlCl3 + ACE200
group, there was a decrease in the number of GFAP+
astrocytes (Figure 4), and these findings are supported
statistically (Figure 4).
Morphometric and statistical results
As compared with the control group, the Purkinje cells in
the AlCl3 group were significantly reduced in number
although Purkinje cells in the AlCl3 + ACE200 group
were significantly increased in number. There was also
a significant increase in the mean number of astrocytes in
AlCl3 group as compared to astrocyte numbers in the
other three groups. There was a significant decrease in the
Table 1. Therapeutic effects of ACE on the transit time spent in
the T-maze by experimental groups.
Groups Trial 1 (sec.) Trial 2 (sec.) Trial 3 (sec.)
Control 13.12 ± 2.12 a
16.57 c
± 4.70 14.88 a
± 1.14
ACE200 12.73 a
± 0.94 14.45 c
± 0.98 15.00 a
± 2.77
AlCl3 18.92 d
± 3.91 25.39 e
± 3.12 23.36 e
± 4.66
AlCl3 + ACE200 15.27 a
± 2.09 20.00 b
± 1.57 18.43 c
± 3.82
Table 2. Therapeutic effects of ACE on AL level in different
groups.
Group Al level (µg/g) wet tissue.
Control
(n = 4)
3.14 ± 0.12
ACE200
(n = 4)
3.92 ± 0.81
AlCl3
(n = 4)
10.34 ± 0.49
P1
< 0.001
P2
< 0.001
AlCl3 + ACE200
(n = 4)
6.27 ± 1.90
P1
< 0.01
P2
< 0.05
P3
< 0.001
Each value represents the mean ± S.D.; P1
: compared to Control, P2:
compared to ACE200, P3:
compared to AlCl3. n= number of rats
Figure 1. Therapeutic effects of ACE on aluminum level in
different groups.
4 H. N. MUSTAFA

Figure 2. Photomicrographs of cerebellar cortex sections from experimental groups. (a) Control group molecular layer (M) has small
stellate cells (SC), and basket cells (BC). The Purkinje cell layer (P) has large pyriform somata with prominent nucleoli, and the
granular layer (G) shows tightly packed small rounded cells with deeply stained nuclei. (b) ACE200 group exhibited normal
morphology. (c) AlCl3 group exhibited a normal molecular layer (M). Few Purkinje cells (arrow) are found in the Purkinje cell layer (P)
and have irregular size, shape, darkly stained nuclei and cytoplasm (arrow). Prominent perineuronal spaces (stars) are seen around
basket (BC) and stellate cells (SC) in the molecular layer (M). The granular layer (G) appears unaﬀected but obvious amyloid plaques
(Aβ) were detected. (d) AlCl3 + ACE200 group molecular (M), the granular (G), and the Purkinje cell layers (P) have restored
appearance and numbers. The Purkinje cells (arrows) are slightly reduced in number. (H&E, Scale bar = 20 µm).
Figure 3. Photomicrographs of cerebellar cortex sections from experimental groups. (a) Control with the three cerebellar layers,
Purkinje (P), molecular (M) and granular (G). (b) ACE200 group exhibits normal morphology. (c) AlCl3 group shows a reduced
number of Purkinje layer cells (arrow) with irregular darkly stained cytoplasm (arrow), and amyloid plaques (Aβ). (d) AlCl3 + ACE200
group shows the Purkinje layer (P) has a restored appearance and number of cells. (Congo red, Scale bar = 20 µm).

mean number of astrocytes in AlCl3 + ACE200 group
(Figures 5 a,b, Table 3).
Data are represented as mean ± SD. P1
: as compared to
control, P2:
as compared to ACE200, P3
: as compared to
AlCl3.
: as compared to
control, P2:
as compared to ACE200, P3
: as compared to
AlCl3.
Bielschowsky results
In AlCl3 group, modiﬁed Bielschowsky results demon-
strated an obvious heavily stained brown amyloid pla-
ques with irregular border in the molecular layer. In
AlCl3 + ACE200 group, the amyloid plaques were
markedly reduced with improvements in the morphol-
ogy of the cerebellum (Figure 6).
Figure 4. Photomicrographs of cerebellar cortex sections from experimental groups. (a) Control group shows GFAP+
astrocytes with
long and thin processes (star) and granular layer protoplasmic astrocytes with thick processes (arrowhead). (b) ACE200 group
exhibited GFAP+
astrocytes with small oligodendrocytes (arrowhead) and spindle-shaped microglia (star). (c) AlCl3 group exhibited
an increase in the number of GFAP+
astrocytes with relatively longer processes (arrowheads). (d) AlCl3 + ACE200 group showed
relatively fewer numbers of astrocytes with thin processes (arrowheads) (GFAP, scale bar = 20 µm).
0
5
10
15
20
25
LineardensityofPurkinje
cells/mmlengthofthefolia
P1 < 0.001
P2 < 0.001
P1 < 0.001
P2 < 0.001
P3 < 0.001
P1 < 0.001
P2 < 0.001
P3 < 0.001
P1 < 0.001
P2 < 0.001
Control ACE200 AlCl3
AlCl3 +
ACE200
Control ACE200 AlCl3
AlCl3 +
ACE200
a
0
1
2
3
4
5
6
AreapercentofGFAP+
astrocytes
b
Figure 5. (a) The linear density of Purkinje cells/mm length of the folia. (b) Area percent of GFAP+
astrocytes.
6 H. N. MUSTAFA

Discussion
The findings of the current study are in accordance with
other studies for cerebellum in Alzheimer’s disease, with
deterioration of the cerebellar volume due to damaged
Purkinje neurons and smalled cell bodies. Dendrites dis-
integration, decline of dendritic fields density, dendritic
spines were lost and a marked increase of focal lipid
storage within the dendritic arborization [4,12,26].
The duration and dose of AlCl3 administration was
selected to induce AD symptoms based on previous find-
ings [27,28]. Even though the dose of AlCl3 may be higher
than routine human exposure (0.4–1.7 mg/kg b.w./day),
humans are sometimes exposed to higher levels of AlCl3
during occupational toxicity and dialysis encephalopathy
[29–31]. Moreover, humans are exposed to aluminum
through various ways such as cooking utensils and drink-
ing water [32].
Aluminum exposure caused a significant decrease in
body and brain weights in rats in a study by Mohamed
and Abd El-Moneium [33] and this could be attributed to
the interference by the aluminum on the hormonal status
and/or protein synthesis [34]. Furthermore, the decrease
in brain weight might be due to increased lipid peroxida-
tion as a consequence of oxidative stress [31].
The AlCl3 group showed a significant decrease in the
behavior scores as compared with the control and AlCl3+
ACE200 group in T-maze test. This study coincided with
Wu, Li et al. that proved the deposition of Aβ plaques
in AD brains impairs learning and memory [35].
Cinnamaldehyde is effective in preventing the tau
knots by prohibiting oxidative stress, as cinnamalde-
hyde binds to two residues of the amino cysteine on the
tau protein. The cysteine residues are vulnerable to
these modifications, which have contributed to the
development of Alzheimer’s disease. This could explain
why ACE reduced the cerebellar Al level in the current
study, may be the other mechanism related to neuro-
protective effects by ACE [36].
In the current study, Al exposure resulted in
a significant reduction in the number of Purkinje cells.
This agreed with studies that reported disorganization of
the Purkinje cell layer with a loss of Purkinje cells with Al
exposure [1]. A darkly stained cytoplasm and pyknotic
nuclei were observed in the Purkinje cells. Pyknosis was
described as irreversible condensation of nuclear chro-
matin in cells undergoing programmed cell death or
apoptosis [37]. These results are in agreement with the
Figure 6. Photomicrographs of cerebellum sections from experimental groups. (a) Control exhibited the three cerebellar layers.
Purkinje (P), molecular (M) and granular (G). (b) ACE200 group displayed the same normal morphological findings as indicated in
Figures 1 and 2. (c) ALCl3 group revealed shrunken pyknotic Purkinje cells and with obvious large, dark irregular amyloid plaques
(Aβ). (d) AlCl3 + ACE200 group showed notable improvement of any signs of degeneration (Bielschowsky, scale bar = 20 µm).
Table 3. The linear density of Purkinje cells/mm length of the
folia and area percent of GFAP+
astrocytes.
Groups Purkinje cells GFAP+
(n = 200)
Control 21.74 ± 0.98 1.37 ± 0.43
ACE200 21.57 ± 0.96 1.54 ± 0.23
AlCl3 3.35 ± 0.71 4.63 ± 0.35
P1
< 0.001 P1
< 0.001
P2
< 0.001 P2
< 0.001
AlCl3+ ACE200 15.73 ± 1.02 2.28 ± 0.83
P1
< 0.001 P1
< 0.001
P2
< 0.001 P2
< 0.001
P3
< 0.001 P3
< 0.001
: compared to control, P2:
compared
to ACE200, P3:
compared to AlCl3. n = 200 is the number of cells counted.

histological findings in the cerebellar cortex after Al treat-
ment investigated by El–Shafei and colleagues [38].
This study showed that the molecular layer was
characterized by the presence of diffuse plaques and
absence of typical neuritic plaques which was in accor-
dance with work by Mavroudis et. al [4]. The main
difference between these two types of plaques was the
amyloid-β protein nature that is present. Diffuse pla-
ques in the cerebellum are known to be positive for the
end specific monoclonal antibodies Aβ 1–42 but not
Aβ 1–40 [12,26]. This agreed with Du et al. who
noticed that metabolites from cerebellar neurons
encouraged the expression of Aβ degrading enzymes
and advance the clearance of Aβ [4].
Astrocytes play active roles in neuronal regulation
and modulation [39]. It has also been suggested that
the loss of astrocyte functions may precede neurode-
generation and aluminum could be a contributing fac-
tor for this loss [40]. Astrocytes are the principal target
of the action of aluminum [39] that can cause astrocyte
death through apoptosis [41].
The current findings showed a significant increase in
GFAP immunoreactivity of astrocytes in AlCl3 group,
which is in accordance with previous findings and may
be related to a generic response of the central nervous
system to neural injury [42]. Injury to the parenchyma
of the brain induced many plump reactive astrocytes.
These researchers added that as a response to injury,
they also observed the production of a dense network
of processes and increased synthesis of GFAP. The role
of astrocytes in central nervous system (CNS) disorders
remains of interest. The present study showed
a significant increase in the number of GFAP+
astro-
cytes in AlCl3 group and this finding indicated that
AlCl3 altered the production and degradation of GFAP,
the marker of reactive astrocytosis. Thus, GFAP
expression has been a relevant marker for studying
neurodegenerative changes. In contrast, other research-
ers have found decreased GFAP expression in the cer-
ebellar cortex [43,44].
Gliosis might be mediated indirectly through the
free radical formation and herbal antioxidants may
help in preventing this reactive gliosis possibly by
reducing the damaging effects of ROS. Based on this
postulation, the use of ACE in the present study sig-
nificantly reduced GFAP expression in cerebellar cor-
tex thus protecting the memory and learned ability as
reported by other authors [9,45].
Conclusion
Aqueous Cinnamon Extract (ACE) may be considered
an efficacious therapeutic strategy to alleviate amyloid-
β plaques. It is recommended to avoid using of alumi-
num cooking utensils, water tubing and to control
occupational exposure.
Disclosure statement
No potential conflict of interest was reported by the author.
ORCID
Hesham N. Mustafa http://orcid.org/0000-0003-1188-
2187
References
[1] Bhalla P, Dhawan DK. Protective role of lithium in
ameliorating the aluminium-induced oxidative stress
and histological changes in rat brain. Cell Mol
Neurobiol. 2009;29(4):513–521.
[2] Krewski D, Yokel RA, Nieboer E, et al. Human health
risk assessment for aluminium, aluminium oxide, and
aluminium hydroxide. J Toxicol Environ Health B Crit
Rev. 2007;10(Suppl 1):1–269.
[3] Bondy SC. Low levels of aluminum can lead to beha-
vioral and morphological changes associated with
Alzheimer’s disease and age-related neurodegenera-
tion. Neurotoxicol. 2016;52:222–229.
[4] Mavroudis IA, Manani MG, Petrides F, et al. Dendritic
and spinal pathology of the Purkinje cells from the
human cerebellar vermis in Alzheimer’s disease.
Psychiatr Danub. 2013;25(3):221–226.
[5] Abu-Taweel GM, Ajarem JS, Ahmad M. Neurobehavioral
toxic effects of perinatal oral exposure to aluminum on the
developmental motor reflexes, learning, memory and
brain neurotransmitters of mice offspring. Pharmacol
Biochem Behav. 2012;101(1):49–56.
[6] Nobakht M, Hoseini SM, Mortazavi P, et al.
Neuropathological changes in brain cortex and hippo-
campus in a rat model of Alzheimer’s disease. Iran
Biomed J. 2011;15(1–2):51–58.
[7] Suvarna KS, Layton C, Bancroft JD. Bancroft’s theory
and practice of histological techniques. UK: Elsevier
Health Sciences; 2019.
[8] Saleh HA, Abd El-Aziz GS, Mustafa HN, et al.
Thymoquinone ameliorates oxidative damage and his-
topathological changes of developing brain
neurotoxicity. J Histotechnol. 2019;1–12.
[9] Frydman-Marom A, Levin A, Farfara D, et al. Orally
administrated cinnamon extract reduces β-amyloid
oligomerization and corrects cognitive impairment in
Alzheimer’s disease animal models. PloS One. 2011;6
(1):e16564.
[10] Mustafa HN, Hussein AM. Does allicin combined with
vitamin B-complex have superior potentials than
alpha-tocopherol alone in ameliorating lead
acetate-induced Purkinje cell alterations in rats? An
immunohistochemical and ultrastructural study. Folia
Morphol (Warsz). 2016;75(1):76–86.
8 H. N. MUSTAFA

[11] Azab K, Mostafa AH, Ali EM, et al. Cinnamon
extract ameliorates ionizing radiation-induced cel-
lular injury in rats. Ecotoxicol Environ Saf. 2011;74
(8):2324–2329.
[12] Mavroudis IA, Fotiou DF, Adipepe LF, et al.
Morphological changes of the human purkinje cells and
deposition of neuritic plaques and neurofibrillary tangles
on the cerebellar cortex of Alzheimer’s disease. Am
J Alzheimers Dis Other Demen. 2010;25(7):585–591.
[13] Peterson DW, George RC, Scaramozzino F, et al.
Cinnamon extract inhibits tau aggregation associated
with Alzheimer’s disease in vitro. J Alzheimers Dis.
2009;17(3):585–597.
[14] Morgan AM, El-Ballal SS, El-Bialy BE, et al. Studies
on the potential protective effect of cinnamon
against bisphenol A- and octylphenol-induced oxi-
dative stress in male albino rats. Toxicol Rep.
2014;1:92–101.
[15] Otto AD. Cinnamon as a supplemental treatment for
impaired glucose tolerance and type 2 diabetes. Curr
Diab Rep. 2010;10(3):170–172.
[16] Parvazi S, Sadeghi S, Azadi M, et al. The effect of
aqueous extract of cinnamon on the metabolome of
plasmodium falciparum using (1)HNMR spectroscopy.
J Trop Med. 2016;2016:3174841.
[17] Justin Thenmozhi A, Raja TR, Janakiraman U, et al.
Neuroprotective effect of hesperidin on aluminium
chloride induced Alzheimer’s disease in Wistar rats.
Neurochem Res. 2015;40(4):767–776.
[18] Cao Z, Wang F, Xiu C, et al. Hypericum perforatum
extract attenuates behavioral, biochemical, and neuro-
chemical abnormalities in Aluminum chloride-
induced Alzheimer’s disease rats. Biomed
Pharmacother. 2017;91:931–937.
[19] Cao Z, Yang X, Zhang H, et al. Aluminum chloride
induces neuroinflammation, loss of neuronal dendritic
spine and cognition impairment in developing rat.
Chemosphere. 2016;151:289–295.
[20] European Food Safety Authority E. Dietary exposure
to aluminium-containing food additives. EFSA
Supporting Publ. 2013;10(4):411E.
[21] Deacon RM, Rawlins JN. T-maze alternation in the
rodent. Nat Protoc. 2006;1(1):7–12.
[22] Farr SA, Ripley JL, Sultana R, et al. Antisense oligonu-
cleotide against GSK-3beta in brain of SAMP8 mice
improves learning and memory and decreases oxida-
tive stress: Involvement of transcription factor Nrf2
and implications for Alzheimer disease. Free Radic
Biol Med. 2014;67:387–395.
[23] Wei Y, Liu D, Zheng Y, et al. Protective effects of
kinetin against aluminum chloride and D-galactose
induced cognitive impairment and oxidative damage
in mouse. Brain Res Bull. 2017;134:262–272.
[24] Justin Thenmozhi A, Dhivyabharathi M, William
Raja TR, et al. Tannoid principles of Emblica officina-
lis renovate cognitive deficits and attenuate amyloid
pathologies against aluminum chloride induced rat
model of Alzheimer’s disease. Nutr Neurosci. 2016;19
(6):269–278.
[25] McGoey TN, Reynolds JN, Brien JF. Chronic prenatal
ethanol exposure-induced decrease of guinea pig
hippocampal CA1 pyramidal cell and cerebellar
Purkinje cell density. Can J Physiol Pharmacol.
2003;81(5):476–484.
[26] Mavroudis IA, Fotiou DF, Manani MG, et al.
Dendritic pathology and spinal loss in the visual cortex
in Alzheimer’s disease: a Golgi study in pathology.
Int J Neurosci. 2011;121(7):347–354.
[27] Nampoothiri M, Kumar N, Venkata Ramalingayya G,
et al. Effect of insulin on spatial memory in aluminum
chloride-induced dementia in rats. Neuroreport.
2017;28(9):540–544.
[28] Saba K, Rajnala N, Veeraiah P, et al. Energetics of
excitatory and inhibitory neurotransmission in alumi-
num chloride model of Alzheimer’s disease: reversal of
behavioral and metabolic deficits by Rasa Sindoor.
Front Mol Neurosci. 2017;10:323.
[29] Niu Q, Yang Y, Zhang Q, et al. The relationship
between Bcl-2 gene expression and learning & mem-
ory impairment in chronic aluminum-exposed rats.
Neurotox Res. 2007;12(3):163–169.
[30] Bhattacharjee S, Zhao Y, Hill JM, et al. Aluminum and
its potential contribution to Alzheimer’s disease (AD).
Front Aging Neurosci. 2014;6:62.
[31] Mathiyazahan DB, Justin Thenmozhi A,
Manivasagam T. Protective effect of black tea
extract against aluminium chloride-induced
Alzheimer’s disease in rats: A behavioural, bio-
chemical and molecular approach. J Funct Foods.
2015;16:423–435.
[32] Ali HA, Afifi M, Abdelazim AM, et al. Quercetin and
omega 3 ameliorate oxidative stress induced by alumi-
nium chloride in the brain. J Mol Neurosci. 2014;53
(4):654–660.
[33] Mohamed NE, Abd El-Moneim AE. Ginkgo biloba
extract alleviates oxidative stress and some neurotrans-
mitters changes induced by aluminum chloride in rats.
Nutrition. 2017;35:93–99.
[34] Wenting L, Ping L, Haitao J, et al. Therapeutic effect of
taurine against aluminum-induced impairment on
learning, memory and brain neurotransmitters in
rats. Neurol Sci. 2014;35(10):1579–1584.
[35] Wu QY, Li J, Feng ZT, et al. Bone marrow stromal
cells of transgenic mice can improve the cognitive
ability of an Alzheimer’s disease rat model. Neurosci
Lett. 2007;417(3):281–285.
[36] George RC, Lew J, Graves DJ. Interaction of cinna-
maldehyde and epicatechin with tau: implications
of beneficial effects in modulating Alzheimer’s dis-
ease pathogenesis. J Alzheimers Dis. 2013;36
(1):21–40.
[37] Venkataraman P, Selvakumar K, Krishnamoorthy G,
et al. Effect of melatonin on PCB (Aroclor 1254)
induced neuronal damage and changes in Cu/Zn
superoxide dismutase and glutathione peroxidase-4
mRNA expression in cerebral cortex, cerebellum and
hippocampus of adult rats. Neurosci Res. 2010;66
(2):189–197.
[38] El–Shafei M-DE-DM, Kamel AMF, Mostafa MEA.
Effect of aluminum on the histological structure of
ratsʼ cerebellar cortex and possible protection by
melatonin. Egypt J Histol. 2011;34(2):239–250.

[39] Araque A, Navarrete M. Glial cells in neuronal net-
work function. Philos Trans R Soc Lond B Biol Sci.
2010;365(1551):2375–2381.
[40] Guo GW, Liang YX. Aluminum-induced apoptosis in
cultured astrocytes and its eﬀect on calcium
homeostasis. Brain Res. 2001;888(2):221–226.
[41] Suarez-Fernandez MB, Soldado AB, Sanz-Medel A,
et al. Aluminum-induced degeneration of astrocytes
occurs via apoptosis and results in neuronal death.
Brain Res. 1999;835(2):125–136.
[42] Nedzvetsky VS, Tuzcu M, Yasar A, et al. Eﬀects of
vitamin E against aluminum neurotoxicity in rats.
Biochemistry (Mosc). 2006;71(3):239–244.
[43] Exley C. Aluminium and Alzheimer’s disease: the
science that describes the link. UK: Elsevier Science;
2001.
[44] Silva AF, Aguiar MS, Carvalho OS, et al. Hippocampal
neuronal loss, decreased GFAP immunoreactivity and
cognitive impairment following experimental intoxica-
tion of rats with aluminum citrate. Brain Res.
2013;1491(Supplement C):23–33.
[45] Modi KK, Roy A, Brahmachari S, et al. Cinnamon and
its metabolite sodium benzoate attenuate the activa-
tion of p21rac and protect memory and learning in an
animal model of Alzheimer’s disease. PloS One.
2015;10(6):e0130398.
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