|ORIGINAL ARTICLE: BIOCHEMISTRY AND NATURAL PRODUCTS
|Year : 2020 | Volume
| Issue : 2 | Page : 74-83
Neuroprotective effect of Egyptian Hyphaene thebaica fruit extract against Alzheimer’s disease in an animal model
Ebtehal K Farrag1, Ahlam H Mahmoud1, Dalia B Fayed1, Nevien M Sabry2
1 Department of Therapeutic Chemistry, National Research Centre, Cairo, Egypt
2 Department of Cell Biology, National Research Centre, Cairo, Egypt
|Date of Submission||28-Oct-2020|
|Date of Decision||14-Oct-2020|
|Date of Acceptance||22-Nov-2020|
|Date of Web Publication||06-Feb-2021|
Ahlam H Mahmoud
Prof.of Biochemistry, Therapeutic Chemistry Department, Pharmaceutical and drug Industries Division, National Research Center, Dokki, 12622
Source of Support: None, Conflict of Interest: None
Background/aim Alzheimer’s disease (AD) is a chronic neurodegenerative disease. The AD incidence is rising and is becoming a heavy economic burden on society and patients’ families. The present study was directed to investigate the protective and therapeutic effects of Hyphaene thebaica fruit extract (HTE) on AD in an animal model.
Materials and methods A total of 90 adult albino male rats were involved in this study and were classified into six groups (15 each). Two negative control groups were used: one did not take any supplementation (G1) and a second negative control group in which normal rats were supplemented with HTE (G2). AD induction was performed by orally injecting the animals with 50 mg AlCl3/kg body weight for 6 weeks. Four groups took AlCl3. First group served as a positive control (G3). Two groups were used to investigate the effect of the orally injected HTE on AD rats either as a therapeutic (G4) or preventive (G5) agent. The last group was treated with the reference drug donepezil (G6). After treatment with HTE for 4 weeks, biochemical analyses of acetylcholinesterase activity, lipid peroxidation (malondialdehyde), and reduced glutathione were done in the brain tissue homogenate. Lipid profile was determined in sera. Expression level assessments of genes encoding microtubule-associated protein tau and amyloid precursor protein were carried out as well as DNA adducts were measured in brain tissues. Histopathological investigations of brain tissues were also performed.
Results The results showed that brain samples of AD group exhibited significant changes in biochemical, molecular, and histopathological parameters. The samples of the groups treated with HTE showed improvements in the studied parameters. The treatment of induced AD group with HTE showed better results than supplementing the extract after occurrence of the signs of Alzheimer.
Conclusion It was concluded that HTE acts as a promising candidate natural product to ameliorate and protect brain injury in AD-induced rats.
Keywords: Alzheimer’s disease, antioxidants, DNA adducts, gene expression, Hyphaene thebaica, tau protein
|How to cite this article:|
Farrag EK, Mahmoud AH, Fayed DB, Sabry NM. Neuroprotective effect of Egyptian Hyphaene thebaica fruit extract against Alzheimer’s disease in an animal model. J Arab Soc Med Res 2020;15:74-83
|How to cite this URL:|
Farrag EK, Mahmoud AH, Fayed DB, Sabry NM. Neuroprotective effect of Egyptian Hyphaene thebaica fruit extract against Alzheimer’s disease in an animal model. J Arab Soc Med Res [serial online] 2020 [cited 2021 Oct 15];15:74-83. Available from: http://www.new.asmr.eg.net/text.asp?2020/15/2/74/308874
| Introduction|| |
The world is experiencing an increasing number of patients with Alzheimer’s disease (AD), resulting in a heavy burden on the national economy. Overall, 70% of all dementia cases are patients with AD . The characteristics of such chronic neurodegenerative disorders are progressive memory loss, affecting social, physical activities as well as the quality of life. In 2012, ∼35.6 million people were experiencing dementia worldwide, which will double every 20 years, reaching 115.4 million in 2050 as reported by the WHO . Accordingly, the health and social burden of these populations will balloon dramatically.
Some biomarkers are common for diagnosing the disease, which help in the identification of definitive therapeutic targets and represent the most important targets for discovering a safe treatment for AD. One of the markers detected in AD diagnosis was the reduction of neurotransmitter acetylcholine synthesis. This suggestion was based on the dysfunction of neurons that contain acetylcholine which substantially contributes to the observation of the cognitive decline in patients with AD . Earlier studies showed deterioration in acetylcholinesterase activity (AChE) in the AD-affected brain .
Reactive oxygen species (ROS) plays a very important target in all neurodegenerative diseases in parallel with AChE as a measure for AD incidence . The reason for focusing on ROS as a target is that it induces damage in mitochondria DNA and neuronal cell nuclei ,. Moreover, it increases lipid peroxidation products and decreases antioxidant enzymes activities . Two major neuropathological features are, till now, the most specific markers for AD diagnosis: extracellular and intracellular. The plaque formation (the amyloid-β protein) is the extracellular one, whereas the intracellular one is represented by neurofibrillary tangles, which consist of hyperphosphorylated tau protein in the form of paired helical filaments. Both the amyloid-β protein and the tau protein are mainly closed to the brain’s hippocampus region and in the cerebral cortex. The two brain parts are responsible for memory and other higher cognitive functions .
DNA and RNA might be damaged by formation of ROS or reactive nitrogen species (RNS), leading to the loss of the nitrogen bases in AD cells. The association of ROS or RNS-mediated DNA damage and over-expression of nitrotyrosine is considered as a molecular marker for the damage of DNA by ROS or RNS . Moreover, DNA damage is associated with lipid peroxidation end products (ALEs), for example, trans-4-hydroxy-2-nonenal, during the DNA-trans-4-hydroxy-2-nonenal adduct generation .
Up to our knowledge, there is no therapeutic treatment for AD, but some drugs are used in the relief of symptoms accompanying the disease. The present study is to investigate a new source of natural agent aiming to achieve an AD treatment which may increase the relief of symptoms of the disease. Herbal medicine is always considered as a safer drug rather than pharmaceutical preparations. The plant Hyphaene thebaica is a desert palm native to India, Egypt, and Africa. It is known as Doum or gingerbread palm. The fruit exhibits antioxidant activity because of the water-soluble phenolics’ presence . It also possesses anti-inflammatory, antihypertensive, and antimicrobial activities owing to the presence of flavonoids ,,.
This study aims to investigate both the protective and therapeutic effects of Hyphaene thebaica fruit extract (HTE) on AD in an animal model by measurements of AChE, lipid peroxidation [malondialdehyde (MDA)], and reduced glutathione (GSH). Moreover, expression level assessments of genes encoding microtubule-associated protein tau (MAPT) and amyloid precursor protein (APP) were carried out. The DNA adducts were measured in brain tissues, and histopathological investigations of brain tissues were also performed.
| Materials and methods|| |
The chemicals used were of high analytical grade (Sigma-Aldrich, St Louis, Missouri, USA). The kits used for the quantitative determination were purchased from Biodiagnostic (Giza, Egypt) and Greiner Diagnostic GmbH (Germany). TRIzol solution was purchased from Invitrogen (Germany). The PCR and reverse transcription kits were purchased from Fermentas (Waltham, Massachusetts, USA). SYBR Green Mix was purchased from Stratagene (San Diego, California, USA).
Dry Doum fruit (H. thebaica) was collected from the local market (Dokki, Giza, Egypt). The plant was documented by Dr Mona Kassem, professor at Phytochemistry and Plant Systematics Department, National Research Center, Egypt.
Overall, 500 g of dry H. thebaica fruit was suspended in 70% ethanol, and then the ethanol was evaporated under vacuum at 40°C, yielding a semisolid free plant extract residue.
All procedures described were reviewed and approved by the Animals Ethical Committee of the National Research Centre, under the ethical number 181/61, and conformed to the ethical guidelines of the 1975 Helsinki Declaration.
A total of 90 adult albino male rats were kindly provided by the Animal House of National Research Centre, Egypt, weighing from 150 to 200 g. Rats were preserved under the same temperature and air conditions with diet and water access. The animals were divided into sex groups as follows (15 each):
Group 1: it included normal healthy rats that received 0.5 ml of 0.9% saline which was considered as a negative control group.
Group 2: it included animals that were daily supplemented with the plant extract (HTE) with the rate of 1.0 g/kg body weight  for 4 weeks and considered as plant extract-treated normal group.
Group 3: it included animals that received aluminum chloride (AlCl3) for 6 weeks with the rate of 50 mg/kg body weight, intermediate dose to cause AD in rats and considered as supportive control group ,.
Group 4: it included animals that received AlCl3 for 6 weeks then treated with HTE for another 4 weeks and considered as therapeutic group.
Group 5: it included animals received HTE and AlCl3 at the same time for 6 weeks and considered as protective group.
Group 6: it included animals that received AlCl3 for 6 weeks and then treated with the reference drug (donepezil) with the rate of 1.5 mg/kg body weight  for another 4 weeks.
All doses were orally administered once daily in the morning. At the end of the experiment period, the blood was collected and centrifuged for the separation of serum for 10 min at 3000 rpm and 4°C. The serum was stored at −80°C for further biochemical investigations. The animals were cervically decapitated, and the brain was immediately removed and washed with saline solution. The brain was dissected and divided into two parts. For lipid peroxidation (MDA) determination, a small piece of the first part of the brain was homogenized in 10% trichloroacetic acid or ice-cold bidistilled water for reduced GSH and AChE. The other piece of the first part of the brain was used for molecular analysis as it stored at −80°C. The second part of the brain was kept immediately in 10℅ formalin buffer for histopathological examination.
Lipid peroxidation (MDA) and reduced GSH were measured according to Ohkawa et al.  and Moron et al.  respectively, using a Biodiagnostic Kit (Cairo, Egypt). Lipid profile [triglycerides, cholesterol, and low-density lipoprotein (LDL)-levels] was determined colorimetrically in sera according to the methods of Rifai et al.  for triglycerides and Deeg and Ziegenhorn  for cholesterol and LDL-levels, using biochemical kits of Greiner Diagnostic GmbH. AChE was estimated spectrophotometrically according to Ellman et al. , which was modified by Gorun et al. .
The percentage of improvement or protection was calculated as follows:
Where T is the mean of the treated group, P is the mean of the positive control group, and C is the mean of the negative control .
Gene expression analysis
Extraction of total RNA and cDNA synthesis
Total RNA was extracted from male rat brain tissues using TRIzol Reagent (Invitrogen) kit. The isolation method was executed in accordance with the instructions given by the manufacturer in the aforementioned kit. The extracted RNA was dissolved in diethylpyrocarbonate water and stored at −80°C till use . Reverse transcription was done to synthesize cDNA ,. The reaction was prepared as per RevertAid First Strand cDNA Synthesis Kit (MBI Fermentas). The cDNA-containing PCR products were preserved at −20°C till use for the amplification of the DNA .
The expression value assessments of the tested genes were done using Step One Real-Time-PCR system (Applied Biosystem, USA), and the cDNA copy number of the male rats was determined. A 25 μl reaction mixture contained 12.5 μl of SYBR green (TaKaRa’ Biotech Co. Ltd., Mountain View, Santa Clara, California, USA), 0.5 μl of 0.2 μM forward and reverse primers each, 6.5 μl of DNAs-RNAs free water, and 2.5 μl of synthesized cDNA. Specific primer sequences of the genes used are listed in [Table 1]. The target genes were quantified related to the reference gene (β-actin) using the 2−ΔΔCT method .
Determination of DNA adducts using high-performance liquid chromatography
DNA from rat brain was extracted according to Ahmed et al. , then digested, and the 8-hydroxy-2-deoxyguanosine (8-OhdG) adduct was measured using CoulArray-equipped high-performance liquid chromatography (Model 5600). The analytes were revealed in two modules of the coulometric array; four sensors of electrochemical were attached in series for each, enabling targets to be identified based on the potential for reduction . The ultraviolet detection had been set to 260 nm. Using CoulArray software, the high-performance liquid chromatography was controlled, and then the data were collected and analyzed. The mobile phase was 5% methanol at pH 5.2 in 50 mmol/l sodium acetate. The potentials of electrochemical detector for 2-deoxy guanosine (2-dG) and 8-OHdG were 120/230/280/420/600/750/840/900 mV and the flow rate was 1 ml/min.
Brain sections from each group were preserved immediately in buffer 10% formalin for staining using hematoxylin and eosin as described by the method of Hirsch et al. .
The data were analyzed through comparison of values for various treatment groups with the individual control values. For each group, all data were expressed as a mean±standard deviation with a 5% rate error. Significant differences between groups were analyzed statistically using an analysis of one-way variances, analysis of variance, using the computer program SPSS, version 16.0 (233 South Wacker Drive, 11th Floor, Chicago, Illinois 60606-6307, USA). The variations were considered significant at P value less than or equal to 0.05.
| Results|| |
In [Table 2], the GSH level was significantly decreased (P≤0.05) in group 3 as compared with control group. Groups 4 and 5 showed significant change (P≤0.05) in GSH level compared with group 3. The level of GSH was increased by 39.49 and 78.97% in groups 4 and 5, respectively.
|Table 2 Effect of Plant extract and donepezil on, glutathione, malondialdehyde, lipid profile, and acetylcholinesterase activity in brain homogenate|
Click here to view
Significant increase (P≤0.05) in MDA level was observed in group 3 brain tissue as compared with group 1. In group 4, MDA levels were significantly decreased (P≤0.05) compared with group 3 and showed improvement by 66.98%. The coadministration of an extract with AlCl3 (group 5) prevents the hazard effect by 99.04%. Meanwhile, the reference drug showed improvement only by 48.32%.
For lipid profile, all studied parameters were increased in group 3. The two supplemented groups with plant extract (groups 4 and 5) showed significant decrease. The improvement in total cholesterol reached 96.59 and 91.10% in groups 4 and 5, respectively. Donepezil showed improvement in total cholesterol only by 81.92%. The % improvement in LDL or triglycerides in the prevented group was ranked former to that in the posttreatment group.
AChE levels increased significantly in rats’ brains upon receiving AlCl3 only for 6 successive weeks compared with group 1 ([Table 2]). However, group 4 showed that AChE level decreased significantly as compared with group 3 (58% improvement). However, rats treated with donepezil exhibited significant decrease in AChE levels when compared with those in the group 3 (92.25% improvement). Interestingly, group 5 showed a significant decrease in AChE (94.34% improvement). The use of plant extract in normal-treated group did not exhibit noticeable changes in all parameters, as seen in [Table 2].
Levels of the 8-OHdG generation in brain tissues of AD-induced rat genome following H. thebaica extract treatment are summarized in [Figure 1]. It was showed that AD induction in rats revealed a significant increase in the 8-OHdG/2-dG ratio compared with those in group 1. The increase in 8-OHdG/2-dG ratio was partially improved owing to supplementation with H. thebaica extract. However, group 5 induced better improvement in 8-OHdG/2-dG ratio than either group 5 or group 6 as compared with group 3 ([Figure 2] and [Figure 3]).
|Figure 1 Generation of 8-OHdG in the brain tissues of male rats treated with Hyphaene thebaica extract with/or after AD induction. DNA damage was expressed as the ratio of oxidized DNA base (8-OHdG) to nonoxidized base (2-dG) in brain DNA. Data are presented as mean±SEM. a, b, c: mean values within column with unlike superscript letters were significantly different (aP<0.001, bP<0.01, dP<0.05). AD, Alzheimer’s disease; 2-dG, 2-deoxy guanosine; 8-OHdG, 8-hydroxy-2-deoxyguanosine.|
Click here to view
|Figure 2 Expression levels of APP gene in brain tissues of AD-induced male rats treated with Hyphaene thebaica extract with/or after AD induction. Data are presented as mean±SEM. a, b, c: followed by different superscripts are significantly different (P≤0.05). a, b, c: percentage values within column with unlike superscript letters were significantly different (aP<0.001, bP<0.01, c, dP<0.05). AD, Alzheimer’s disease; APP, amyloid precursor protein.|
Click here to view
|Figure 3 Expression levels of MAPT gene in brain tissues of AD-induced male rats treated with Hyphaene thebaica extract with/or after AD induction. Data are presented as mean±SEM. a, b, c: percentage values within column with unlike superscript letters were significantly different (aP<0.001, bP<0.01, cP<0.05, abP>0.05 compared with a or b). AD, Alzheimer’s disease; MAPT, microtubule-associated protein tau.|
Click here to view
The expression levels of the genes related to AD pathways, including MAPT and APP, in brain tissues of AD rats were quantified by real-time-PCR ([Figure 2] and [Figure 3]). AD induction in rats significantly increased the expression of the APP gene in brain tissue when compared with that in groups 1 and 2. The percentage of the mRNA expression of the APP gene in group 3 was higher than those in group 1 ([Figure 2]). This increase was ameliorated by using HTE either as groups 4 and 5. The elevated level of APP gene expression was reduced in group 5 greater than that in either group 4 or group 6 ([Figure 2]). In group 3, there was a markable increase in APP gene expression compared with group 1. The decrease in expression levels of MAPT gene was ameliorated in the groups 4, 5, and 6 ([Figure 3]).
Brain sections from different groups are shown in [Figure 4] and [Figure 5]. Group 1 showed normal histological features ([Figure 4]a–c), a well-defined molecular layer, a large number of small cells in the granular layer, and large Purkinje cells that present in the cell layer of Purkinje, as well as almost normal neuronal cells, no edema, no interstitial neuronal atrophy, and no shrinkage. Group 2 declared normal histological picture ([Figure 4]d–f). Group 3 illustrated marked distortion in granular cell layer, sparse cell distribution of Purkinje layer, and a marked reduction in cellular size of the molecular layer; there is moderate edema and interstitial neuronal atrophy and shrinkage ([Figure 4]g–i). Group 4 showed a well-defined molecular layer of small cells carefully packed into the granular layer and large Purkinje cells ([Figure 5]a–c). Group 5 displayed the cerebellum has normal histological features, showing a very clear molecular layer and the presence of numerous carefully packed small cells in the granular layer, and large Purkinje cells ([Figure 5]d–f). Group 6 declared seminormal histological features with edema and interstitial neuronal atrophy and shrinkage ([Figure 5]g–i).
|Figure 4 Photomicrographs of brain sections in control, control extract, and AD group. (a, b, c) Group 1: brain section of normal control rat showing the cerebellum with normal histological features, illustrating a well-defined molecular layer (black arrow), presence of numerous closely packed small cells in the granular layer (red arrow), and large Purkinje cells in the Purkinje cell layer (yellow arrow). (d, e, f) Group 2: control extract showing the cerebellum with normal histological features: a well-defined molecular layer, numerous closely packed small cells in the granular layer, and large Purkinje cells in the Purkinje cell layer. (g, h, i) Group 3: brain section of AD group, showing cerebellum with marked distortion in granular cell layer (sparse cell distribution), sparse cell distribution of Purkinje layers, and marked reduction in cellular size of the molecular layer, as well as moderate edema and interstitial neuronal atrophy and shrinkage (green arrow) (hematoxylin and eosin stain, ×100, ×400, ×400). AD, Alzheimer’s disease.|
Click here to view
|Figure 5 Photomicrographs of brain sections in therapeutic, prevention, and reference drug groups. (a, b, c) Group 4: brain section of rat with extract therapeutic group showed the cerebellum with normal histological features: a well-defined molecular layer (black arrow), presence of numerous closely packed small cells in the granular layer (red arrow), and large Purkinje cells in Purkinje cell layer (yellow arrow), as well as edema and interstitial neuronal atrophy and shrinkage (green arrow). (d, e, f) Group 5: brain section of rat with ALCl3+ plant (prevention) showed the cerebellum with normal histological features: a well-defined molecular (black arrow), presence of numerous closely packed small cells in the granular layer (red arrow), and large Purkinje cells in Purkinje cell layer (yellow arrow), and almost normal neuronal cells (green arrow). (g, h, i) Group 6: brain section of rat with AlCl3+reference drug showed the cerebellum with normal histological features, illustrating a well-defined molecular (black arrow), presence of numerous closely packed small cells in the granular layer (red arrow), and large Purkinje cells in the Purkinje cell layer (yellow arrow), as well as edema and interstitial neuronal atrophy and shrinkage (green arrow) (hematoxylin and eosin stain, ×100, ×400, ×400).|
Click here to view
| Discussion|| |
AD is a multifactorial disease. Hence, one target therapy is not effective . Drug discovery from natural products to control AD is a current trend. Although H. thebaica (Doum) has been used in folk medicine in Egypt since a long time, there is no single publication concerning its effect on AD. In this study, the antioxidant capacity of Doum extract caused amelioration in GSH and MDA levels in rats injected with AlCl3 for AD induction.
As a fact, the antioxidant defense mechanisms decrease in neurodegenerative diseases and during aging, causing increase in oxidative stress . Free radicals evolved through oxidative stress injure the abundant polyunsaturated fatty acids in brain ,. Elimination of ROS essentially depends on GSH redox cycle, as it represents the first defense against oxidative stress .
One of the helpful strategy in controlling AD is the elimination of free radicals by supplemented antioxidant ,. Flavonoids that are rich in HTE , can be one of the reasons in controlling the redox state. Sureda et al.  proved that flavonoids increase GSH content and reduce MDA level. The increased GSH level in AD rats treated with HTE is a good sign for the effect of HTE as an antioxidant.
Pure flavonoids or total extracts can minimize pro-inflammatory cytokines (IL-6, TNF-α, IL-1β, and COX-2) expression, and consequently, prevent neural damage and diminish inflammatory markers .
Tannin, one of the HTE constituents , possesses strong anti-inflammatory and antioxidant properties. It also shows a neuroprotective effect against AD in several in vitro and in vivo models of AD .
The increases in LDL, cholesterol, and triglycerides levels in AD model are parallel with different authors ,,. These increases are strong AD pathogenesis risk factor, inducing brain deposition of amyloid-beta precursor protein and the increase in amyloid-beta (Aβ) accumulation in neuronal endolysosomes, leading to neuroinflammation .
The total LDL, cholesterol, and triglycerides levels in brain were ameliorated in rat treated with oral HTE. Three therapeutics approved by FDA, are donepezil, rivastigmine, and galantamine. These drugs act as choline esterase inhibitors. However, their adverse effects lead to cholinergic activation in other central and peripheral pathways, some of which are severe . H. thebaica extract succeeded to inhibit the enzyme AChE activity in AD rats. Its effect on choline esterase can be attributed to the presence of phenolic acids and flavonoids ,.
Aβ accumulation in the brain is commonly assumed to be the starting trigger of a pathological cascade that ultimately results in synaptic dysfunction and its loss, neuronal death, and ultimately cognitive dysfunction . Accordingly, the APP expression and the MAPT expression were assessed. The results revealed significant increase in the APP gene expression and decrease in MAPT expression in AD rats. High generation of DNA adduct levels in the form of OHdG/2-dG ratio was marked in AD rats.
The present results showed that HTE could be able to regulate the expression of APP and MAPT genes as well as decrease the generation of DNA adducts compared with those in AD rats. These findings coincide with Mohebali et al. , who declared that flavonoids and phenolic compounds extracted from medicinal plants regulated gene expression of Alzheimer-related disease.
All measured parameters in this study were assured with the histological results, where they showed an accumulation of fibrillar, extensive neuronal loss proteins such as extracellular Aβ plaques, and neurofibrillary tangles within neurons in AD brain, which coincides with Clark . These pieces of evidence lead to impairment of mechanisms of axonal integrity and neurodegenerative disorders. Neurite degeneration through the destabilization of microtubule proteins could be the key factor that induces impairment and memory loss in patients with AD. The administration of HTE to AD rats improved AD pathogenesis as shown by a decreased rate of AChE and increased antioxidant parameters in the brain, which was further supported by an improvement in the brain tissue characteristics of histopathological analysis. Increase in the size of neuronal bodies and layer in HTE-treated AD rats relative to that found in AD untreated rats (positive control) provides a neuroanatomical basis that may enhance learning and memory abilities, as found in previous studies .
| Conclusion|| |
In conclusion, the administration of HTE to AD rats improved the pathogenesis of AlCl3. This was proved by the amelioration of the studied biochemical, gene expression, and histological parameters.
The treatment of AD rats with HTE on day one of AlCl3 induction showed better results than supplementing the extract after occurrence of the signs of Alzheimer.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Marfany A, Sierra C, Camafort M, Domenech M, Coca A. High blood pressure, Alzheimer disease and antihypertensive treatment. Panminerva Med 2018; 60:8–16.
Dementia A. Public health priority. Geneva: World Health Organization; 2012.
Terry JrAV, Buccafusco JJ. The cholinergic hypothesis of age and Alzheimer’s disease-related cognitive deficits: recent challenges and their implications for novel drug development. J Pharmacol Exp Ther 2003; 306:821–827.
Auld DS, Kar S, Quirion R. β
-amyloid peptides as direct cholinergic neuromodulators: a missing link?. Trends Neurosci 1998; 21:43–49.
Butterfield DA, Reed T, Newman SF, Sultana R. Roles of amyloid beta-peptide-associated oxidative stress causes damage in neuronal cell nuclei and mitochondria oxidative stress and brain protein modifications in the pathogenesis of Alzheimer’s disease and mild cognitive impairment. Free Radic Biol Med 2007; 43:658–677.
Mecocci P, MacGarvey U, Beal MF. Oxidative damage to mitochondrial DNA is increased in Alzheimer’s disease. Ann Neurol 1994; 36:747–751.
Greenamyre JT, Betarbet R, Sherer TB. The rotenone model of Parkinson’s disease: genes, environment and mitochondria. Parkinsonism Relat Disord 2003; 9:S59–S64.
Markesbery WR. Oxidative stress hypothesis in Alzheimer’s disease. Free Radic Biol Med 1997; 23:134–147.
Rizk MZ, Borai IH, Ezz MK, El-Sherbiny M, Aly HF, Matloub A, Fouad GI. Possible therapeutic role of grape (Vitis vinifera
) leaves polyphenolic extract in the regression of aluminium-induced Alzheimer’s disease in rats. J Mater Environ Sci 2018; 9:2098–2108.
Su JH, Deng G, Cotman CW. Neuronal DNA damage precedes tangle formation and is associated with up-regulation of nitrotyrosine in Alzheimer’s disease brain. Brain Res 1997; 774:193–199.
Götz ME, Wacker M, Luckhaus C, Wanek P, Tatschner T, Jellinger K et al.
Unaltered brain levels of 1, N2-propanodeoxyguanosine adducts of trans-4-hydroxy-2-nonenal in Alzheimer’s disease. Neurosci Lett 2002; 324:49–52.
Cook JA, VanderJagt DJ, Dasgupta A, Mounkaila G, Glew RS, Blackwell W, Glew RH. Use of the Trolox assay to estimate the antioxidant content of seventeen edible wild plants of Niger. Life Sci 1998; 63:105–110.
Irobi ON, Adedayo O. Antifungal activity of aqueous extract of dormant fruits of Hyphaene thebaica
(Palmae). Pharma Biol 1999; 37:114–117.
Elegami AA, Almagboul AZ, Omer MEA, El Tohami MS. Sudanese plants used in folkloric medicine: screening for antibacterial activity. Part X. Fitoterapia 2001; 72:810–817.
Eltayeb EM, Abdalla AA, Eltohami MS. Anti-inflammatory study and phytochemical analysis of Hyphaene thebaica
(Doum plant). Planta Med 2009; 75:PJ185.
Tohamy AA, Abdalla MS, Ibrahim AK, Ahmed KA, Mahran KF, Mohammed RS. The effect of Lupinus albus and Hyphaene thebaica on chromosomal aberrations and histopathological changes of liver and pancreas in streptozotocin-induced diabetic rats. Egypt J Hosp Med 2013; 53:763–769.
Krasovskiĭ GN, Vasukovich LY, Chariev OG. Experimental study of biological effects of leads and aluminum following oral administration. Environ Health Perspect 1979; 30:47–51.
Lakshmi BVS, Sudhakar M, Surya Prakash K. Protective effect of selenium against aluminum chloride-induced Alzheimer’s disease: behavioral and biochemical alterations in rats. Biol Trace Elem Res 2015; 165:67–74.
Stein C, Hopfeld J, Lau H, Klein J. Effects of Ginkgo biloba
extract EGb 761, donepezil and their combination on central cholinergic function in aged rats. J Pharm Pharm Sci 2015; 18:634–646.
Ohkawa H, Ohishi N, Yagi K. Assay for lipid peroxides in animal tissues by thiobarbituric acid reaction. Anal Biochem 1979; 95:351–358.
Moron MS, Depierre JW, Mannervik B. Levels of glutathione, glutathione reductase and glutathione S-transferase activities in rat lung and liver. Biochim Biophys Acta 1979; 582:67–78.
Rifai N, Bachorik PS, Albers JJ. Lipids, lipoproteins and apolipoproteins. In: Burtis CA, Ashwood ER, editors. Tietz Textbook of Clinical Chemistry. 3rd ed., Philadelphia: W.B. Saunders Company; 1999. pp. 809–861.
Deeg R, Ziegenhorn J. Kinetic enzymic method for automated determination of total cholesterol in serum. Clin Chem 1983; 29:1798–1802.
Ellman GL, Courtney KD, Andres V, Featherstone RM. A new and rapid colorimetric determination of acetylcholinesterase activity. Biochem Pharmacol 1961; 7:88–95.
Gorun V, Proinov I, Baltescu V, Balaban G, Barzu O. Modified Ellman procedure for assay of cholinesterases in crude enzymatic preparations. Anal Biochem 1978; 86:324–326.
Elsharabasy FS, Metwally NS, Mahmoud AH, Soliman MS, Youness ER, Farrag AH. Phytoconstituents and hepatoprotective effect of Suaeda monoica
Forssk and Suaeda pruinosa Lange. Biomed Pharmacol J 2019; 12:117–129.
Khalil WKB, Booles HF. Protective role of selenium against over-expression of cancer-related apoptotic genes induced by O-cresol in rats. Arh Hig Rada Toksikol 2011; 62:121–129.
El-Baz FK, Aly HF, Khalil WKB, Booles HF, Saad SA. Jatropha curcas repairing effect on adhesion molecules, DNA damage and gene expression alteration in STZ-induced diabetic rats. Int J Pharma Bio Sci 2015; 6:B198–B214.
Ahmed HH, Booles HF, Khalil WKB, El Ashmaoui HM, Othman SM. Possible therapeutic role of Jasonia candicans and Jasonia montana
extracts in the regression of Alzheimer’s disease in experimental model. Am J Biochem Biotechnol 2013; 9:144–161.
Stein TD, Johnson JA. Lack of neurodegeneration in transgenic mice overexpressing mutant amyloid precursor protein is associated with increased levels of transthyretin and the activation of cell survival pathways. J Neurosci 2002; 22:7380–7388.
Miyazaki T, Baba TT, Mori M, Moriishi T, Komori T. Microtubule-associated protein tau (MAPT) is expressed in terminally differentiated odontoblasts and severely down-regulated in morphologically disturbed odontoblasts of Runx2 transgenic mice. Cell Tissue Res 2015; 361:457–466.
Deng Y, Xu ZF, Liu W, Xu B, Yang HB, Wei YG. Riluzole-triggered GSH synthesis via activation of glutamate transporters to antagonize methylmercury-induced oxidative stress in rat cerebral cortex. Oxid Med Cell Longev 2012; 2012:534705.
Hirsch C, Zouain CS, Alves JB, Goes AM. Induction of protective immunity and modulation of granulomatous hypersensitivity in mice using PIII, an anionic fraction of Schistosoma mansoni
adult worm. Parasitology 1997; 115:21–28.
Carreiras MC, Mendes E, Perry MJ, Francisco AP, Marco Contelles J. The multifactorial nature of Alzheimer’s disease for developing potential therapeutics. Curr Top Med Chem 2013; 13:1745–1770.
Buffenstein R, Edrey YH, Yang T, Mele J. The oxidative stress theory of aging: embattled or invincible? Insights from non-traditional model organisms. Age 2008; 30:99–109.
Lu GA, Wang ZH, Zhang H, Rong ZH, Chao SU, Yang LI et al.
Protective effects of shikonin on brain injury induced by carbon ion beam irradiation in mice. Biomed Environ Sci 2015; 28:148–151.
Sun DQ, Li AW, Li J, Li DG, Li YX, Gong MZ. Changes of lipid peroxidation in carbon disulfide-treated rat nerve tissues and serum. Chem Biol Interact 2009; 179:110–117.
Zeraatpishe A, Malekirad AA, Nik-Kherad J, Jafari A, Yousefi Babadi S, Tanwir F. The effects of caffeine supplements on exercise-induced oxidative damages. Asian J Sports Med 2015; 6:e23023.
Hamilton A, Holscher C. The effect of ageing on neurogenesis and oxidative stress in the APPswe/PS1deltaE9 mouse model of Alzheimer’s disease. Brain Res 2012; 1449:83–93.
Aliev G, Priyadarshini M, Reddy VP. Oxidative stress mediated mitochondrial and vascular lesions as markers in the pathogenesis of Alzheimer disease. Curr Med Chem 2014; 21:2208–2217.
Dosumu OO, Nwosu FO, Nwogu CD. Antimicrobial studies and phytochemical screening of extracts of Hyphaene thebaica
(Linn) Mart fruits. Int J Trop Med 2006; 1:186–189.
Auwal MS, Tijjani A, Lawan FA, Mairiga IA, Ibrahim A, Njobdi AB et al.
The quantitative phytochemistry and hypoglycaemic properties of crude mesocarp extract of Hyphaene thebaica
(doumpalm) on normoglycemic Wistar albino rats. J Med Sci 2012; 12:280–285.
Sureda A, Xavier C, Tejada S. Neuroprotective effects of flavonoid compounds on neuronal death associated to Alzheimer’s disease. Curr Med Chem 2019; 26:5124–5136.
Spagnuolo C, Moccia S, Russo GL. Anti-inflammatory effects of flavonoids in neurodegenerative disorders. Eur J Med Chem 2017; 153:105–115.
Braidy N, Jugder BE, Poljak A, Jayasena T, Mohammad Nabavi S, Sachdev P, Grant R. Molecular targets of tannic acid in Alzheimer’s disease. Curr Alzheimer Res 2017; 14:861–869.
Chen X, Gawryluk JW, Wagener JF, Ghribi O, Geiger JD. Caffeine blocks disruption of blood brain barrier in a rabbit model of Alzheimer’s disease. J Neuroinflammation 2008; 5:1–4.
Hui L, Chen X, Geiger JD. Endolysosome involvement in LDL cholesterol-induced Alzheimer’s disease-like pathology in primary cultured neurons. Life Sci 2012; 9:1159–1168.
Fiorenza MT, Dardis A, Canterini S, Erickson RP. Cholesterol metabolism-associated molecules in late onset Alzheimer’s disease. J Biol Regul Homeost Agents 2013; 27:23–35.
Perry VH, Newman TA, Cunningham C. The impact of systemic infection on the progression of neurodegenerative disease. Nat Rev Neurosci 2019; 4:103–112.
Deardorff WJ, Feen E, Grossberg GT. The use of cholinesterase inhibitors across all stages of Alzheimer’s disease. Drugs Aging 2015; 32:537–547.
Szwajgier D. Anticholinesterase activity of selected phenolic acids and flavonoids- interaction testing in model solutions. Ann Agri Environ Med 2015; 22:690–694.
Nguyen TK, Im KH, Choi J, Shin PG, Lee TS. Evaluation of antioxidant, anti-cholinesterase, and anti-inflammatory effects of culinary mushroom Pleurotus pulmonarius
. Mycobiology 2016; 44:291–301.
Walsh DM, Selkoe DJ. Deciphering the molecular basis of memory failure in Alzheimer’s disease. Neuron 2004; 44:181–193.
Mohebali N, Shahzadeh Fazeli SA, Ghafoori H, Farahmand Z, MohammadKhani E, Vakhshiteh F et al.
Effect of flavonoids rich extract of Capparis spinosa on inflammatory involved genes in amyloid-beta peptide injected rat model of Alzheimer’s disease. Nutr Neurosci 2018; 21:143–150.
Clark CM. Clinical manifestations and diagnostic evaluation of patients with Alzheimer’s disease. In: Clark CM, Trojanowski JQ, editors. Neurodegenerative dementias: clinical features and pathological mechanisms. New York: McGraw-Hill 2000; 95:114.
Yassin N, El-Shenawy S, Mahdy KA, Gouda N, Marrie AE, Farrag A, Ibrahim BM. Effect of Boswellia serrata on Alzheimer’s disease induced in rats. J Arab Soc Med Res 2013; 8:1–11. [Full text]
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]
[Table 1], [Table 2]