Oalib Open Access Library Journal 2333-9721 2333-9705 Scientific Research Publishing 10.4236/oalib.1114980 Oalib-150212 Article Biomedical Life Sciences Business Economics Chemistry Materials Science Computer Science Communications Earth Environmental Sciences Engineering Medicine Healthcare Physics Mathematics Social Sciences Humanities Phenylethanoid Glycosides (AIE2)-Enriched Cistanche tubulosa Extract Attenuates Oxidative Stress and Amyloid Pathology in an Aβ1−40-Induced Rat Model of Alzheimer’s Disease Chou Chin-Tsai 1 Chao Chien-Liang 2 Huang Wen-Fang 2 Wu Ya-Ting 2 Huang Ya-Hui 2 Lin Hang-Ching 1 2 Su Muh-Hwan 2 3 SynCore Biotechnology Co., Ltd., Taipei City Sinphar Pharmaceutical Co., Ltd., Sinphar Group, Yilan School of Pharmacy, NDMC, Taipei City

The authors declare no conflicts of interest.

 28 02 2026 02 2026 13 03 1 22 03 02 2026 14 03 2026 17 03 2026 © 2026 by the authors and Scientific Research Publishing Inc. 2026 This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license ( https://creativecommons.org/licenses/by/4.0/ ). https://doi.org/10.4236/oalib.1114980

The mechanisms underlying accelerated cognitive decline in Alzheimer’s disease (AD) remain incompletely understood. Accumulating evidence suggests that AD is a complex, multifactorial neurodegenerative disorder in which oxidative stress plays a central role. Oxidative stress, often triggered by amyloid-β (Aβ)-induced reactive oxygen species (ROS), leads to severe cellular damage and contributes to cognitive deterioration. This study investigated the effects of phenylethanoid glycosides (AIE2)-enriched Cistanche tubulosa extract (CTE) on oxidative stress, cognitive impairment, and AD-like pathology in an Aβ1−40-induced rat model. The AD-like model was established by hippocampal infusion of Aβ1−40. Antioxidant enzyme activities, including superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase, were evaluated. CTE treatment significantly attenuated Aβ1−40-induced oxidative stress, enhanced antioxidant enzyme activities, and improved cognitive performance in the AD-like animal model. Toxicological evaluation revealed no adverse effects, as evidenced by stable body weight and unchanged liver and kidney function parameters. Additionally, CTE reduced acetylcholinesterase activity as well as Aβ1−40 and apolipoprotein E deposition without inducing toxicity. These findings suggest that CTE exerts antioxidant and neuroprotective effects and may represent a promising therapeutic candidate for the treatment of Alzheimer’s disease.

 <i>Cistanche tubulosa</i> Phenylethanoid Glycosides Alzheimer’s Disease Oxidative Stress A<i>β</i><sub>1-40</sub> 1. Introduction

Alzheimer’s disease (AD), the most common form of dementia, is pathologically characterized by extracellular amyloid-β (Aβ) plaque deposition and intracellular tau-containing neurofibrillary tangles. These pathological features lead to a progressive decline in memory, cognitive function, speech, performance, and orientation, predominantly affecting the elderly population [1]. Managing behavioral symptoms in patients with AD presents a substantial challenge for caregivers, highlighting the importance of preserving cognitive function and slowing disease progression to alleviate this burden. Consequently, increasing research efforts have focused on the development of therapeutic agents to improve cognitive and memory impairments associated with AD. However, despite the approval of several drugs by the U.S. Food and Drug Administration (FDA), effective disease-modifying treatments remain unavailable [2].

Oxidative stress is widely recognized as a critical contributor to the pathogenesis and progression of AD, playing a pivotal role in neuronal damage and cognitive decline [3][4]. Although several studies have demonstrated the antioxidant and neuroprotective properties of glycosides derived from Cistanche tubulosa and their potential to attenuate Aβ-induced AD-like symptoms in animal models [5]-[7], their specific effects on oxidative stress in Aβ-induced AD-like models remain to be fully elucidated.

Although the precise mechanisms underlying AD remain incompletely understood, accumulating evidence identifies Aβ-induced neurotoxicity and oxidative stress as key pathological events [8]. Aβ accumulation is widely accepted as a central factor in AD development [9]. Impaired degradation and clearance of Aβ proteins promote amyloid fibril formation and plaque deposition, leading to cholinergic neuron degeneration, synaptic loss, and ultimately neurodegeneration and cognitive impairment [10]. In parallel, oxidative stress has been implicated as a major driver of AD pathogenesis, initiating and exacerbating disease progression [11]. An imbalance between reactive oxygen species (ROS) production and antioxidant defense mechanisms results in excessive ROS accumulation, leading to oxidative stress. In the brain, this process induces neuroinflammation, damages DNA, RNA, and proteins, impairs mitochondrial function, and ultimately contributes to neurodegeneration and cognitive dysfunction [12].

Aβ accumulation further exacerbates neuronal oxidative stress by inducing excessive ROS production [13], thereby triggering apoptotic signaling pathways and neuronal cell death [14]. Notably, oxidative stress may precede Aβ plaque deposition and tau phosphorylation [15] and can further promote Aβ generation and aggregation.¹⁶ Given the central role of oxidative stress in AD pathogenesis, increasing attention has been directed toward therapeutic strategies aimed at mitigating oxidative damage [11][16].

Cistanche tubulosa (Schrenk) R. Wight, a parasitic plant primarily distributed in the Taklamakan Desert, has been used in traditional Chinese medicine for thousands of years, as documented in Shennong’s Materia Medica and the Pharmacopeia of Chinese mainland and Taiwan region [17][18]. Traditionally, C. tubulosa has been employed to treat various conditions, including kidney deficiency, impotence, female infertility, morbid leucorrhea, profuse metrorrhagia, and senile constipation.

C. tubulosa extract (CTE), which is rich in phenylethanoid glycosides [19][20], has been reported to possess a broad spectrum of pharmacological activities, including antioxidant, neuroprotective, anti-inflammatory, immunomodulatory, anti-aging, and cognition-enhancing effects, as well as potential therapeutic benefits for AD [21]. Increasing evidence further supports the role of phenylethanoid glycosides in the treatment of neurodegenerative diseases such as AD, Parkinson’s disease, and vascular dementia [22]-[24]. Several studies have identified the major glycosidic constituents of C. tubulosa [25][26], among which acteoside and echinacoside are the predominant compounds. These constituents have demonstrated neuroprotective effects and the ability to alleviate memory impairment [27]-[29]. Moreover, C. tubulosa extracts exhibit significant antioxidant activity [30][31] and have been shown to enhance intracellular antioxidant defenses by increasing the activities of enzymes such as superoxide dismutase (SOD) and glutathione peroxidase (GPx) [32]. However, whether CTE effectively attenuates oxidative stress—a critical factor in AD pathogenesis—remains unclear.

As increasing attention has been directed toward the neuroprotective potential of phenylethanoid glycosides, numerous studies have reported their beneficial effects in AD models. These compounds have been shown to alleviate neurological deficits and reduce neuronal apoptosis in AD animal models [7][33]. Furthermore, phenylethanoid glycosides have demonstrated the capacity to enhance learning and memory by promoting the expression of nerve growth factors [34]. Our previous studies also revealed that acteoside and echinacoside effectively inhibit Aβ accumulation and aggregation in both in vitro cellular systems and in vivo animal models [7][35]. Despite evidence supporting the antioxidant properties of isolated glycosides from C. tubulosa and the established role of oxidative stress in AD, the effects of CTE on oxidative stress in AD remain insufficiently characterized. Therefore, the present study aimed to investigate the effects of CTE on oxidative stress, key antioxidant enzyme activities, and cognitive and memory impairments in an Aβ1−40-infused AD-like rat model [36][37].

 2. Materials and Methods 2.1. Experimental Materials

Powdered stems of Cistanche tubulosa were extracted by water reflux and subsequently filtered to obtain the filtrate. Ethanol was added to the filtrate, after which the supernatant was collected and subjected to resin separation using macroporous adsorption resin. The resulting extract was spray-dried to obtain the aqueous C. tubulosa extract (CTE), with a yield of approximately 10%. The extract was manufactured by Sinphar Tian-Li Pharmaceutical Co., Ltd. (Hangzhou, Sinphar Group, China).

CTE primarily consists of phenylethanoid glycosides, including acteoside, isoacteoside, echinacoside, and 2′-acetylechinacoside (AIE2). A cholinesterase inhibitor (0.52 mg/kg) was used as a positive control. Synthetic human Aβ1−40 peptide was purchased from Tocris Bioscience (Ellisville, MO, USA).

 2.2. Animals

A total of 63 male Sprague-Dawley rats (250 - 300 g) were obtained from BioLASCO Taiwan region Co., Ltd. Animals were housed under controlled environmental conditions (25˚C ± 1˚C, 60% relative humidity) with free access to standard laboratory chow and tap water and maintained on a 12-h light/dark cycle (light phase: 09:00 - 21:00). All rats were acclimated for one week prior to experimentation, and body weight was recorded daily throughout the study.

Rats were randomly assigned to seven groups (n = 9 per group):

1)Control group (sham-operated): saline infusion and oral administration of distilled water

2)AC group: Aβ1−40 infusion and oral administration of distilled water

3)AM group: Aβ1−40 infusion and oral administration of a cholinesterase inhibitor (0.52 mg/kg)

4)AS0.5 group: Aβ1−40 infusion and oral administration of CTE (14.6 mg/kg/day)

5)AS1 group: Aβ1−40 infusion and oral administration of CTE (29.2 mg/kg/day)

6)AS2 group: Aβ1−40 infusion and oral administration of CTE (58.4 mg/kg/day)

7)AS6 group: Aβ1−40 infusion and oral administration of CTE (175.2 mg/kg/day)

CTE and the cholinesterase inhibitor were administered once daily via gastric gavage for 28 days. Following behavioral assessments, rats were fasted for 12 h prior to sacrifice for biochemical, histological, and safety evaluations.

The CTE doses were extrapolated from a previous clinical trial using a standardized human dose of 300 mg/day (AS1) [21]. Additional doses of 150 mg/day (AS0.5), 600 mg/day (AS2), and 1800 mg/day (AS6) were calculated and converted to rat-equivalent doses using body surface area normalization, resulting in doses of 14.6, 29.2, 58.4, and 175.2 mg/kg/day, respectively.

All experimental procedures were approved by the Institutional Animal Care and Use Committee (IACUC) of NTU (Approval No. 12, Year 98) and were conducted in accordance with the Guiding Principles for the Care and Use of Laboratory Animals (Protocol No. 99-127-B).

 2.3. A <italic>β</italic> <sub>1</sub> <sub>−</sub> <sub>40</sub> -Infused AD-Like Rat Model and Experimental Schedule

The AD-like rat model was established by continuous hippocampal infusion of Aβ1−40, as previously described [36][37]. Briefly, rats were anesthetized via intraperitoneal injection of sodium pentobarbital (45 mg/kg) and placed in a stereotaxic apparatus (S724791, Narishige, Tokyo, Japan). An infusion cannula was implanted into the lateral ventricle, and a mini-osmotic pump (Alzet 2002; Alza, Palo Alto, CA, USA) was implanted subcutaneously in the posterior neck region.

Aβ1−40 was dissolved in 35% acetonitrile containing 0.1% trifluoroacetic acid to a concentration of 250 pmol/μL and loaded into the mini-osmotic pumps. Beginning one day after implantation (day 0), pumps delivered Aβ1−40 at a rate of 300 pmol/day for 28 days. Control animals received the same volume of vehicle solution.

From day 1 onward, CTE, cholinesterase inhibitor, or vehicle (distilled water) was administered intragastrically once daily throughout the infusion period. On behavioral testing days, treatments were administered 1 h prior to testing, including the passive avoidance test (days 19 - 21) and the Morris water maze (days 22 - 27). On day 28, rats were sacrificed 1 h after the final administration for biochemical and histological analyses, including measurements of malondialdehyde (MDA), antioxidant enzyme activities (SOD, catalase, GPx, GRd), acetylcholinesterase (AChE) activity, and serum biochemical parameters.

 2.4. Oxidative Stress Measurements

Lipid peroxidation was assessed using a thiobarbituric acid–reactive substances (TBARS) assay kit (Cayman Chemical, #10009055). Samples were reacted with thiobarbituric acid (TBA), and absorbance was measured at 540 nm using a microplate reader. Lipid peroxidation levels were expressed as malondialdehyde (MDA) equivalents based on a standard curve.

Oxidative DNA damage was evaluated by measuring 8-hydroxy-2′-deoxyguanosine (8-oxo-dG), a commonly used biomarker of oxidative stress. DNA oxidation was quantified using a commercial ELISA kit (Trevigen, #4380-096-K) according to the manufacturer’s instructions. Absorbance was measured at 450 nm, and 8-oxo-dG concentrations were calculated using a standard curve.

Protein oxidation was assessed by measuring protein carbonyl content using a commercial kit (Cayman Chemical, #10005020). Absorbance was measured at 360 - 385 nm, and results were expressed as nmol carbonyl per mg protein.

 2.5. Antioxidant Enzyme Activity Assays

Superoxide dismutase (SOD) activity was measured using a commercial assay kit (Ransod-SD125, Randox Laboratories, UK). Absorbance was measured at 505 nm, and activity was expressed as U/mg protein. Catalase activity was determined using a commercial kit (Cayman Chemical, #707002) by measuring formaldehyde production at 540 nm and expressed as mM/min/mL. Glutathione peroxidase (GPx) activity was measured using a coupled enzymatic assay (Cayman Chemical, #703102), with activity expressed as nmol NADPH/min/mg protein. Glutathione reductase (GRd) activity was assessed using a commercial kit (Cayman Chemical, #703202), with enzyme activity expressed as nmol NADPH/min/mg protein.

 2.6. Cortical and Hippocampal AChE Activity

AChE activity was determined using a modified Ellman method [38]. Samples were incubated with 5,5′-dithiobis(2-nitrobenzoic acid), followed by acetylthiocholine. Absorbance was measured at 412 nm, and enzyme activity was expressed as U/mg protein.

 2.7. Hematological Analysis

Serum biochemical parameters related to lipid metabolism, liver function, and kidney function were analyzed, including triglycerides, total cholesterol, HDL-C, LDL-C, AST, ALT, alkaline phosphatase, total protein, albumin, globulin, blood urea nitrogen, uric acid, electrolytes (Na⁺, K⁺, Cl⁻), calcium, and phosphorus.

 2.8. Immunohistochemistry

Brain tissues were fixed in 10% formalin, embedded in paraffin, and sectioned at 3 - 5 μm thickness. Sections were dewaxed, rehydrated, and subjected to antigen retrieval. After blocking with 10% goat serum, sections were incubated overnight at 4˚C with antibodies against Aβ1−40 or ApoE (1:100). Detection was performed using an HRP-conjugated system with DAB chromogen, followed by hematoxylin counterstaining.

Protein expression was quantified using mean integrated optical density (IOD) from three randomly selected fields per section at 400× magnification. Aβ plaque counts were performed in at least 20 fields per section at 40× magnification using an image analyzer (Leica Q500MC).

 2.9. Behavioral Tests

Passive Avoidance Test:

The passive avoidance test was conducted as previously described. Retention latency times were recorded at 24, 48, and 72 h post-training.

Morris Water Maze Test:

Spatial learning and memory were assessed using reference memory, probe, and working memory tasks in a Morris water maze, as previously described. Escape latency, swimming distance, and quadrant occupancy were recorded using EthoVision® XT tracking software.

 2.10. Statistical Analysis

All data were analyzed using SPSS version 17.0. Group differences were evaluated by one-way analysis of variance (ANOVA), followed by Dunnett’s post hoc test. Data are presented as mean ± SD (n = 9). A value of p < 0.05 was considered statistically significant.

 3. Results 3.1. Effects of <italic>C. tubulosa</italic> Extract (CTE) on Oxidative Stress in the Hippocampus and Serum of A <italic>β</italic> <sub>1-40</sub> -Induced AD Rats

Oxidative stress is a critical contributor to the development and progression of Alzheimer’s disease (AD), leading to neuronal damage and cognitive decline [3]. In contrast, C. tubulosa extract (CTE) has been reported to possess antioxidant properties [30][31]. To evaluate the antioxidant potential of CTE against Aβ aggregation–induced oxidative stress, malondialdehyde (MDA)—a lipid peroxidation end product and a commonly used marker of oxidative stress [37]—was measured in hippocampal tissues of Aβ1-40-induced AD rats. As shown in Figure 1(a), hippocampal MDA levels were significantly elevated in the Aβ1-40-infused control group compared with the non-infused group. CTE administration significantly and dose-dependently attenuated the Aβ1-40-induced increase in MDA levels relative to the Aβ1-40-infused control group. Systemic oxidative stress was further assessed by measuring plasma markers of lipid peroxidation (MDA), protein oxidation (protein carbonyls), and DNA oxidation (8-hydroxy-2′-deoxyguanosine, 8-OHdG) [39]. Plasma MDA levels exhibited a pattern similar to that observed in hippocampal tissues (Figure 1(b)), with significantly higher levels in

Figure 1. CTE effects on oxidative stress in Aβ1-40-infused rats. MDA levels in the hippocampus (a) and blood plasma (b) were measured to evaluate lipid peroxidation. 8-OHdG (c) and protein carbonyl (d) levels were measured to assess oxidative stress on DNA and proteins, respectively. The results are presented as mean ± SD (n = 9). *p < 0.05 indicates statistical significance compared to the AC control group.

the Aβ1-40-infused control group compared to the non-infused group. CTE treatment resulted in a dose-dependent reduction of plasma MDA levels relative to the Aβ1-40-infused control group. Similarly, plasma 8-OHdG levels were significantly increased following Aβ1-40 infusion compared with the non-infused group (Figure 1(c)), whereas CTE administration dose-dependently decreased 8-OHdG levels. In addition, protein carbonyl levels—a marker of protein oxidation—were markedly elevated in the Aβ1-40-infused control group compared with the non-infused group and were dose-dependently reduced by CTE treatment (Figure 1(d)).

 3.2. Effects of CTE on Antioxidant Enzyme Activities in the Hippocampus of A <italic>β</italic> <sub>1-40</sub> -Induced AD Rats

To further elucidate the relationship between the antioxidant effects of CTE and the reduction of Aβ1-40-induced oxidative stress, the activities of key antioxidant enzymes—including superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx), and glutathione reductase (GRd)—were assessed. SOD catalyzes the conversion of superoxide radicals into hydrogen peroxide, which is subsequently decomposed into water and oxygen by catalase and peroxidases. GRd plays a critical role in maintaining GPx activity by regenerating reduced glutathione from glutathione disulfide [40]. As shown in Figure 2(a), SOD activity was significantly

Figure 2. CTE effects on antioxidant enzyme activities (SOD, catalase, GPx, and GRd) in the hippocampus of Aβ1-40-infused rats. (a) Superoxide dismutase (SOD); (b) Catalase; (c) Glutathione peroxidase (GPx); and (d) Glutathione reductase (GRd) activities in hippocampal tissue are shown. The results are presented as mean ± SD (n = 9). *p < 0.05 indicates statistical significance compared to the AC control group.

reduced in the Aβ1-40-infused control group compared with the non-infused group. CTE administration significantly and dose-dependently increased SOD activity relative to the Aβ1-40-infused control group. Notably, the highest CTE dose (AS6) restored SOD activity to levels comparable to those observed in the non-infused group. Similarly, catalase, GPx, and GRd activities were significantly decreased in the Aβ1-40-infused control group compared with the non-infused group. CTE treatment resulted in dose-dependent increases in the activities of these enzymes (Figures 2(b)-(d)). Interestingly, higher doses of CTE (AS2 and AS6) increased catalase activity beyond the levels observed in the non-infused group. Taken together, these results indicate that CTE enhances the activities of major antioxidant enzymes in a dose-dependent manner, supporting its potential therapeutic role in mitigating Aβ1-40-induced oxidative stress in AD.

 3.3. Effects of CTE on Learning and Memory Assessed by the Passive Avoidance Test in A <italic>β</italic> <sub>1-40</sub> -Induced AD Rats

To assess the effects of CTE on Aβ1-40-induced learning and memory impairment, a passive avoidance test was performed. As shown in Figure 3Figure 3, the Aβ1-40-infused control group exhibited significantly reduced retention latency times to enter the dark chamber compared with the non-infused group on days 1, 2, and 3. CTE administration significantly and dose-dependently increased retention latency times relative to the Aβ1-40-infused control group at all testing time points. Notably, rats receiving the highest CTE dose (AS6) exhibited retention latencies comparable to those of the non-infused group. These findings indicate that CTE effectively ameliorated Aβ1-40-induced deficits in learning and memory as assessed by the passive avoidance test.

 3.4. Effects of CTE on Spatial Memory in A <italic>β</italic> <sub>1-40</sub> -Induced AD Rats Assessed by the Morris Water Maze

Spatial learning and memory were further evaluated using the Morris Water Maze

Figure 3. CTE effects on passive avoidance task in Aβ1-40-infused rats. The latency of entering the dark compartment was recorded. The results are presented as the mean ± SD (n = 9). *p < 0.05 indicates statistical significance.

(MWM). In the reference memory task, the Aβ1-40-infused control group displayed significantly prolonged escape latencies compared with the non-infused group on days 1, 2, and 3 (Figure 4(a)). In contrast, CTE treatment significantly and dose-dependently reduced escape latencies relative to the Aβ1-40-infused control group. In the probe test, the Aβ1-40-infused control group spent a significantly lower percentage of time in the target platform area compared with the non-infused group (Figure 4(b)). CTE administration dose-dependently increased the time spent in the target area relative to the Aβ1-40-infused control group. No significant differences were observed in total swimming distance among groups (Figure 4(c)), indicating that locomotor activity was not affected and did not confound the cognitive outcomes. To further assess working memory, the MWM working memory task was conducted. The Aβ1-40-infused control group exhibited significantly prolonged escape latencies compared with the non-infused group on days 1, 2, and 3 (Figure 4(d)). CTE-treated groups showed dose-dependent reductions in escape latency relative to the Aβ1-40-infused control group, indicating improved working memory performance.

Figure 4. CTE effects on cognitive performance in Aβ1-40-infused rats. (a) Escape latency in the reference memory task. (b) Percentage of time spent in quadrant 4 during the probe test, where the escape platform was previously located. (c) Total swimming distance during the probe test. (d) Escape latency in the working memory task. Results are expressed as mean ± SD (n = 9).

3.5. Effects of CTE on Body Weight and Serum Biochemical Parameters in A <italic>β</italic> <sub>1-40</sub> -Induced AD Rats

Potential toxicity associated with CTE administration was evaluated throughout the experimental period. No significant differences in body weight were observed among the experimental groups (Table 1). Additionally, serum biochemical parameters related to lipid metabolism, liver function, and kidney function—including AST, ALT, alkaline phosphatase, total protein, albumin, globulin, A/G ratio, BUN, creatinine, uric acid, and electrolytes (sodium, potassium, chloride, calcium, and phosphorus)—did not differ significantly among groups compared with the non-infused controls (Table 2 and Table 3). These findings indicate that neither Aβ1-40 infusion nor CTE administration produced detectable hepatic or renal toxicity during the experimental period.

Table 1. Effect of the CTE on body weight.

Treatment Body weight (g)
Week 0 Week 1 Week 2 Week 3 Week 4
C 316.4 ± 6.3 334.6 ± 5.7 353.6 ± 5.7 386.2 ± 4.2 417.6 ± 1.6
AC 313.8 ± 5.1 336.1 ± 7.5 352.2 ± 5.0 386.6 ± 3.1 414.7 ± 3.7
AM 316.3 ± 8.1 333.9 ± 6.7 355.3 ± 8.1 388.4 ± 5.9 417.2 ± 8.5
AS0.5 309.8 ± 5.4 335.8 ± 6.2 348.8 ± 5.4 382.6 ± 6.6 413.3 ± 5.4
AS1 316.4 ± 3.7 332.9 ± 2.4 355.4 ± 3.7 389.3 ± 8.0 415.1 ± 8.3
AS2 313.4 ± 4.2 335.2 ± 6.6 352.4 ± 4.2 386.7 ± 3.1 414.7 ± 5.7
AS6 311.3 ± 6.9 331.3 ± 6.9 350.3 ± 6.9 386.0 ± 5.9 415.9 ± 6.2

Data were presented as means ± SD (n = 9). Abbreviations: C: sham with regular diet; AC: Aβ1-40-infused with regular diet; AM: Aβ1-40-infused with cholinesterase inhibitor drug at 0.52 mg/day/kg bw; AS0.5: Aβ1-40-infused with 14.6 mg/day/kg bw of CTE; AS1: Aβ1-40-infused with 29.2 mg/day/kg bw of CTE; AS2: Aβ1-40-infused with 58.4 mg/day/kg bw of CTE; AS6: Aβ1-40-infused with 175.2 mg/day/kg bw of CTE.

Table 2. Summary of hematology and biochemistry parameters for rats’ lipid metabolism and liver function.

Treatment Triglyceride (mg/dL) Cholesterol (mg/dL) HDL-C (mg/dL) LDL-C (mg/dL) Cholesterol/HDL-C CPK (U/L) AST (U/L) ALT (U/L) Alk-p (IU/L) Total protein (g/dL) Albumin (g/dL) Globulin (g/dL) Albumin/Globulin
C 72.6 ± 3.1 71.7 ± 4.1 57.5 ± 5.3 11.9 ± 1.8 1.2 ± 0.1 780.3 ± 59.8 113.3 ± 8.4 45.4 ± 2.9 130.4 ± 5.1 7.1 ± 0.3 4.7 ± 0.2 2.4 ± 0.2 2.0 ± 0.3
AC 74.0 ± 6.9 68.9 ± 5.3 58.9 ± 5.0 9.0 ± 1.9 1.2 ± 0.1 745.2 ± 81.0 113.0 ± 6.0 47.2 ± 3.9 131.4 ± 7.2 7.2 ± 0.2 4.9 ± 0.2 2.2 ± 0.1 2.2 ± 0.2
AM 73.0 ± 4.1 72.9 ± 4.6 60.5 ± 6.4 10.4 ± 1.5 1.2 ± 0.1 722.6 ± 42.0 116.3 ± 6.1 47.1 ± 5.0 135.6 ± 7.3 7.0 ± 0.3 4.7 ± 0.2 2.3 ± 0.3 2.0 ± 0.3
AS0.5 72.7 ± 5.1 70.8 ± 5.1 60.9 ± 6.3 11.1 ± 1.5 1.2 ± 0.1 720.2 ± 71.6 113.6 ± 6.4 48.0 ± 5.8 130.4 ± 9.2 7.2 ± 0.3 4.9 ± 0.2 2.2 ± 0.2 2.2 ± 0.2
AS1 72.1 ± 3.9 70.0 ± 5.3 58.9 ± 6.8 10.8 ± 1.9 1.2 ± 0.2 726.3 ± 56.7 110.8 ± 6.8 45.7 ± 6.6 132.2 ± 6.8 7.0 ± 0.4 4.5 ± 0.3 2.5 ± 0.4 1.9 ± 0.3
AS2 72.1 ± 3.0 73.6 ± 5.6 59.2 ± 10.9 10.6 ± 2.2 1.3 ± 0.2 733.6 ± 80.9 115.4 ± 4.3 45.6 ± 3.3 129.7 ± 4.9 6.9 ± 0.5 4.8 ± 0.3 2.1 ± 0.3 2.3 ± 0.4
AS6 70.0 ± 6.3 70.8 ± 4.6 61.1 ± 7.0 9.4 ± 1.9 1.2 ± 0.1 739.8 ± 41.7 116.3 ± 8.3 47.4 ± 4.2 133.0 ± 8.2 6.9 ± 0.3 4.6 ± 0.3 2.3 ± 0.2 2.1 ± 0.3

Table 3. Summary of hematology and biochemistry parameters for electrolytes and kidney function in rats.

Treatment BUN (mg/dL) Uric acid (mg/dL) Sodium (mg/L) Potassium (mg/L) Chloride (mg/L) Calcium (mg/dL) Phosphorus (mg/dL)
C 22.6 ± 3.0 5.7 ± 1.5 150.1 ± 1.1 7.6 ± 1.0 91.9 ± 1.7 12.5 ± 0.6 17.3 ± 3.4
AC 20.6 ± 4.0 6.6 ± 1.6 148.9 ± 1.0 7.0 ± 0.6 91.1 ± 1.6 12.7 ± 0.3 15.4 ± 2.7
AM 21.0 ± 4.0 6.3 ± 2.3 148.2 ± 1.9 7.5 ± 1.8 91.9 ± 1.7 12.6 ± 0.8 15.6 ± 3.7
AS0.5 20.9 ± 2.3 6.0 ± 1.9 149.9 ± 1.6 7.1 ± 0.9 91.8 ± 1.8 12.8 ± 0.6 16.3 ± 2.1
AS1 17.9 ± 4.3 6.2 ± 1.5 148.4 ± 1.8 7.2 ± 1.2 93.4 ± 1.8 12.5 ± 0.6 13.7 ± 2.7
AS2 17.1 ± 2.0 6.3 ± 2.5 148.0 ± 2.2 7.3 ± 1.4 92.5 ± 1.9 12.5 ± 0.9 13.7 ± 2.5
AS6 20.2 ± 2.5 5.0 ± 1.7 148.0 ± 1.8 7.3 ± 1.0 93.9 ± 1.3 12.4 ± 0.6 14.4 ± 2.1

Data were presented as means ± SD (n = 9). Abbreviations: C: sham with normal diet; AC: Aβ1-40-infused with normal diet; AM: Aβ1-40-infused with cholinesterase inhibitor drug at 0.52 mg/day/kg bw; AS0.5: Aβ1-40-infused with 14.6 mg/day/kg bw of CTE; AS1: Aβ1-40-infused with 29.2 mg/day/kg bw of CTE; AS2: Aβ1-40-infused with 58.4 mg/day/kg bw of CTE; AS6: Aβ1-40-infused with 175.2 mg/day/kg bw of CTE. Blood urea nitrogen, BUN. High-Density Lipoprotein-Cholesterol, HDL-C; Low-Density Lipoprotein-Cholesterol, LDL-C; Creatine Protein Kinase, CPK; Aspartate aminotransferase, AST; Alanine aminotransferase, ALT; Alkaline Phosphatase, Alk-p.

 3.6. Effects of CTE on Acetylcholine Levels, A <italic>β</italic> <sub>1-40</sub> Deposition, and ApoE Deposition in the Hippocampus of A <italic>β</italic> <sub>1-40</sub> -Induced AD Rats

Reduced acetylcholine (ACh) levels are a hallmark of AD pathology, largely due to excessive hydrolysis by acetylcholinesterase (AChE) [41]. The effects of CTE on brain AChE activity are shown in Figure 5Figure 5. Aβ1-40 infusion significantly increased AChE activity in both hippocampal and cortical tissues compared with the control group. CTE administration significantly attenuated this Aβ1-40-induced hyperactivation of AChE. The effects of CTE on Aβ1-40 deposition were evaluated using immunohistochemical staining of hippocampal sections. As shown in Figure 6(a) and Figure 6(b), Aβ1-40-infused rats exhibited significantly higher percentages of Aβ1-40-immunopositive areas compared with controls. CTE treatment dose-dependently reduced Aβ1-40 deposition in hippocampal tissues relative to the Aβ1-40-infused group. Given the role of apolipoprotein E (ApoE) in Aβ aggregation and AD pathogenesis, as well as its reported co-deposition with Aβ in amyloid plaques [42], ApoE deposition was also assessed. The Aβ1-40-infused group showed significantly increased ApoE-immunopositive areas in both hippocampal and cortical tissues compared with controls. CTE administration resulted in dose-

Figure 5. CTE effects on AChE activity in the hippocampus and cortex of Aβ1-40-infused rats. AChE activity was measured in the hippocampus (a) and cortex (b). The results are expressed as mean ± SD (n = 9).

Figure 6. CTE effects on Aβ1-40 and ApoE depositions in Aβ1-40-infused rats. Brain sections were stained with anti-Aβ1-40 (a) and anti-ApoE (c) antibodies using immunohistochemistry. Aβ1-40-stained plaques were counted in at least 20 fields per brain section under 40X magnification with an image analyzer (Leica, Q500MC, Nussloch, Germany). The percentages of Aβ1-40 (b) and ApoE (d) depositions were quantified. Results are expressed as mean ± SD (n = 9).

dependent reductions in ApoE deposition in both regions (Figure 6(c) and Figure 6(d)). Overall, these results demonstrate that CTE effectively reduced Aβ1-40 accumulation, ApoE deposition, and AChE activity in Aβ1-40-induced AD rats, supporting its neuroprotective potential.

 4. Discussion

Oxidative stress plays a pivotal role in the development and progression of Alzheimer’s disease (AD), contributing to neuronal damage and cognitive decline [3]. Elevated oxidative stress has been reported in both central and peripheral biological systems in AD-like animal models [4][43] as well as in patients with AD [43][44]. Given its central involvement in AD pathogenesis, therapeutic strategies aimed at mitigating oxidative stress warrant further investigation. In the present study, we evaluated the neuroprotective potential of a phenylethanoid glycosides–enriched Cistanche tubulosa extract (CTE) against oxidative stress and memory impairment in Aβ1-40-infused rats.

To better model the chronic nature of AD pathology, we modified the conventional Aβ1-40-induced AD-like animal model by administering continuous daily Aβ1-40infusions throughout the experimental period, rather than a single injection. Previous studies have commonly employed a single Aβ injection to induce AD-like pathology, including oxidative stress and cognitive impairment [36][45]. However, continuous daily Aβ infusion more closely mimics the sustained accumulation of Aβ observed in the AD brain. Using this modified model, we observed pronounced oxidative stress, evidenced by elevated MDA levels in hippocampal tissue and blood plasma, increased plasma 8-OHdG levels, and enhanced protein carbonyl formation (Figure 1). In parallel, the activities of key antioxidant enzymes—SOD, catalase, GPx, and GRd—were significantly reduced in the hippocampus (Figure 2), accompanied by marked impairments in learning and memory (Figure 3Figure 3 and Figure 4) compared with sham-operated rats. These findings are consistent with previous reports showing that intra-hippocampal Aβ injection increases hippocampal ROS and MDA levels, reduces antioxidant defenses, and induces cognitive deficits [46].

The temporal relationship between oxidative stress and Aβ deposition in AD remains a topic of debate. Accumulating evidence suggests a bidirectional interaction between oxidative stress and Aβ accumulation. Oxidative stress may precede Aβ plaque formation and tau phosphorylation [15][47], thereby promoting Aβ generation and aggregation [11]. Conversely, Aβ accumulation induces neuronal oxidative stress through excessive ROS production [13], leading to apoptotic signaling and neuronal cell death [14]. Indeed, Aβ-injected mice display AD-like features, including oxidative stress, neuronal apoptosis, and cognitive impairment [48]. This oxidative burden contributes to neuro inflammation, synaptic dysfunction, and neuronal loss, ultimately manifesting as memory and cognitive decline in AD patients [49]. Our findings support this reciprocal relationship, demonstrating that prolonged Aβ accumulation induces substantial oxidative stress accompanied by diminished antioxidant enzyme activities. Collectively, these results suggest that continuous daily hippocampal infusion of Aβ1-40 represents a robust model for investigating Aβ-driven oxidative stress, hippocampal degeneration, and associated cognitive deficits.

Importantly, our results demonstrate that CTE effectively attenuated several key pathological features induced by Aβ1-40, including Aβ deposition (Figure 6), elevated acetylcholinesterase (AChE) activity (Figure 5Figure 5), and impairments in learning and memory (Figure 3Figure 3 and Figure 4). Notably, CTE administration significantly reduced oxidative stress markers while restoring antioxidant enzyme activities in a dose-dependent manner (Figure 1 and Figure 2). Consistent with our findings, previous studies have shown that CTE enhances antioxidant capacity by upregulating enzymes such as SOD and GPx [32], and its antioxidant properties have been widely documented [30][31]. These observations suggest that the protective effects of CTE against Aβ1-40-induced AD-like pathology are mediated, at least in part, through its ability to suppress oxidative stress and reinforce endogenous antioxidant defenses.

Lipids, particularly polyunsaturated fatty acids (PUFAs), are highly susceptible to oxidative damage due to the lipid-rich composition of the brain [50]. Lipid peroxidation has been proposed as an early event in AD pathogenesis [51], and the hippocampus—rich in PUFAs—is especially vulnerable to oxidative injury. In the present study, hippocampal lipid peroxidation was significantly increased in Aβ1-40-infused rats and markedly attenuated by CTE treatment (Figure 1(a) and Figure 1(b)). Furthermore, ApoE-bound lipid particles enriched in PUFAs are particularly prone to peroxidation [52]. Our results revealed that increased lipid peroxidation in Aβ1-40-infused rats coincided with enhanced ApoE deposition, both of which were significantly reduced following CTE administration. Emerging evidence suggests that oxidative stress may impair ApoE and its receptor ApoER2 via lipid peroxidation of critical functional domains, thereby disrupting the entorhinal-hippocampal memory system in sporadic AD [47]. Nevertheless, the causal relationship between oxidative stress and pathological ApoE accumulation remains controversial [53]. Given ApoE’s established role in Aβ clearance, plaque formation, and co-deposition [54], further studies are required to clarify the interplay among oxidative stress, ApoE dysfunction, and Aβ pathology.

Our previous work demonstrated that CTE can cross the blood-brain barrier and chelate redox-active iron ions [35]. Increasing evidence implicates brain iron dyshomeostasis in AD pathogenesis, with oxidative stress and iron imbalance being closely intertwined [55]. Aβ peptides can bind redox-active metal ions, including iron, thereby promoting oxidative damage and neuronal death [13][56]. Dysregulated iron metabolism can also drive free radical generation via the Fenton reaction, resulting in extensive damage to lipids, proteins, and nucleic acids [55]. Moreover, disturbances in redox homeostasis and iron availability can induce severe lipid peroxidation and trigger ferroptotic cell death [57]. Together with our findings, these studies suggest that oxidative stress in AD arises from multiple interconnected mechanisms involving Aβ accumulation and iron dysregulation, forming a deleterious feedback loop that exacerbates disease progression [58]-[60].

AD is characterized by progressive cognitive decline and memory loss, ultimately leading to severe dementia and imposing substantial caregiving, economic, and societal burdens. Although several FDA-approved drugs are available for AD treatment [2], their clinical benefits remain limited, reflecting the complex and multifactorial nature of AD pathology. In the present study, CTE administration significantly ameliorated Aβ1-40-induced cognitive and memory impairments, at least in part through its antioxidant effects. While the therapeutic efficacy of antioxidants in AD remains controversial—given the lack of FDA-approved antioxidant-based therapies [11]—the present findings, together with our previous studies [7] and those of others [34], highlight the multi-targeted neuroprotective properties of CTE.

The diverse bioactive components of CTE, particularly echinacoside and acteoside, have been shown to exert neuroprotective effects through multiple mechanisms, including the attenuation of AD-related pathology [7][20][21][26]. Notably, echinacoside has been reported to inhibit Aβ deposition and improve cognitive function in APP/PS1 transgenic mice via activation of the PI3K/Akt/Nrf2/PPARγ signaling pathways [39]. Moreover, C. tubulosa aqueous extract has been approved in China as a botanical drug for vascular dementia [35]. Although limited by small sample size, an open-label, non-placebo-controlled clinical study suggested that CTE may stabilize cognitive function and daily living activities in patients with mild to moderate AD, with efficacy comparable to long-term acetylcholinesterase inhibitor therapy [21]. While the precise mechanisms underlying the protective effects of phenylethanoid glycosides from C. tubulosa remain to be fully elucidated, their ability to target multiple pathological pathways simultaneously positions CTE as a promising candidate for the development of alternative or adjunctive therapeutic strategies for AD.

Nonetheless, this study has certain limitations. First, the oxidative stress markers, Aβ/ApoE deposition, and behavioral outcomes were evaluated as individual endpoints, and the causal relationships among these parameters were not established. Second, the antioxidant pathway and anti-amyloid effects were interpreted as parallel outcomes, as no mechanistic linkage between them was directly examined.

 5. Conclusion

The findings of this study demonstrate that CTE significantly attenuated oxidative stress in Aβ1-40-induced AD rats, accompanied by enhanced activities of key antioxidant enzymes. These results support the hypothesis that the mitigation of Aβ1-40-induced AD-like pathology by CTE is mediated, at least in part, through the suppression of oxidative stress and the reinforcement of endogenous antioxidant defenses. In addition, CTE reduced acetylcholinesterase activity as well as Aβ1-40 and apolipoprotein E deposition, without inducing detectable toxicity. Collectively, these findings indicate that CTE exerts robust antioxidant and neuroprotective effects and may represent a promising therapeutic candidate for the prevention or treatment of Alzheimer’s disease.

 Acknowledgments

We are grateful to Sinphar Pharmaceutical group for providing the commercial natural product (C. tubulosa extract (Sinphar AIE2)).

 Authors’ Contributions

Conceptualization, M.-H.S.; methodology, H.-C.L; formal analysis, C.-T.C and C.-L.C and Y.-H.H; investigation, Y.-T.W; Critical revision of manuscript, C.-T.C and C.-L.C; writing—original draft preparation, C.-T.C and W.-F.H; writing—review and editing, M.-H.S. All authors have read and agreed to the published version of the manuscript.

 Availability of Data and Materials

Data will be made available on request.

 Ethical Approval

This study was approved by the Institutional Animal Care and Use Committee (IACUC) of NTU (Approval No. 12, Year 98).

 Statement of Human and Animal Rights

All of the experimental procedures involving animals were conducted in accordance with the Guiding Principles for the Care and Use of Laboratory Animals (Protocol No. 99-127-B) and approved by the Institutional Animal Care and Use Committee (IACUC) of NTU.

 Statement of Informed Consent

There are no human subjects in this article and informed consent is not applicable.

 Statement of Consent

The authors give their consent for personal information related to the subject to be published by OALib publishing.

 References Najem, D., Bamji-Mirza, M., Chang, N., Liu, Q.Y. and Zhang, W. (2014) Insulin Resistance, Neuroinflammation, and Alzheimer’s Disease. ReviewsintheNeurosciences, 25, 509-525. https://doi.org/10.1515/revneuro-2013-0050 10.1515/revneuro-2013-005024622783https://doi.org/10.1515/revneuro-2013-0050 Najem, D. Bamji-Mirza, M. Chang, N. Liu, Q.Y. Zhang, W. Resistance, N 2014 Insulin Resistance, Neuroinflammation, and Alzheimer’s Disease Reviews in the Neurosciences 25 10.1515/revneuro-2013-0050 24622783 Briggs, R., Kennelly, S.P. and O’Neill, D. (2016) Drug Treatments in Alzheimer’s Disease. ClinicalMedicine, 16, 247-253. https://doi.org/10.7861/clinmedicine.16-3-247 10.7861/clinmedicine.16-3-24727251914https://doi.org/10.7861/clinmedicine.16-3-247 Briggs, R. Kennelly, S.P. Neill, D. 2016 Drug Treatments in Alzheimer’s Disease Clinical Medicine 16 10.7861/clinmedicine.16-3-247 27251914 Cheignon, C., Tomas, M., Bonnefont-Rousselot, D., Faller, P., Hureau, C. and Collin, F. (2018) Oxidative Stress and the Amyloid Beta Peptide in Alzheimer’s Disease. RedoxBiology, 14, 450-464. https://doi.org/10.1016/j.redox.2017.10.014 10.1016/j.redox.2017.10.01429080524https://doi.org/10.1016/j.redox.2017.10.014 Cheignon, C. Tomas, M. Bonnefont-Rousselot, D. Faller, P. Hureau, C. Collin, F. 2018 Oxidative Stress and the Amyloid Beta Peptide in Alzheimer’s Disease Redox Biology 14 10.1016/j.redox.2017.10.014 29080524 Rapaka, D., Bitra, V.R., Ummidi, R. and Akula, A. (2021) Benincasa hispida Alleviates Amyloid Pathology by Inhibition of Keap1/nrf2-Axis: Emphasis on Oxidative and Inflammatory Stress Involved in Alzheimer’s Disease Model. Neuropeptides, 88, 102151. https://doi.org/10.1016/j.npep.2021.102151 10.1016/j.npep.2021.10215133932860https://doi.org/10.1016/j.npep.2021.102151 Rapaka, D. Bitra, V.R. Ummidi, R. Akula, A. 2021 Benincasa hispida Alleviates Amyloid Pathology by Inhibition of Keap1/nrf2-Axis: Emphasis on Oxidative and Inflammatory Stress Involved in Alzheimer’s Disease Model Neuropeptides 88 10.1016/j.npep.2021.102151 33932860 Chen, Y., Li, Y., Fang, J., Li, P. and Li, F. (2020) Establishment of the Concurrent Experimental Model of Osteoporosis Combined with Alzheimer’s Disease in Rat and the Dual-Effects of Echinacoside and Acteoside from Cistanche tubulosa. JournalofEthnopharmacology, 257, Article ID: 112834. https://doi.org/10.1016/j.jep.2020.112834 10.1016/j.jep.2020.11283432278031https://doi.org/10.1016/j.jep.2020.112834 Chen, Y. Li, Y. Fang, J. Li, P. Li, F. 2020 Establishment of the Concurrent Experimental Model of Osteoporosis Combined with Alzheimer’s Disease in Rat and the Dual-Effects of Echinacoside and Acteoside from Cistanche tubulosa Journal of Ethnopharmacology 257 112834 ID 10.1016/j.jep.2020.112834 32278031 Liao, Y., Wang, J., Guo, C., Bai, M., Ran, Z., Wen, L., et al. (2023) Cistanche tubulosa Alleviates Ischemic Stroke-Induced Blood-Brain Barrier Damage by Modulating Microglia-Mediated Neuroinflammation. JournalofEthnopharmacology, 309, Article ID: 116269. https://doi.org/10.1016/j.jep.2023.116269 10.1016/j.jep.2023.11626936863639https://doi.org/10.1016/j.jep.2023.116269 Liao, Y. Wang, J. Guo, C. Bai, M. Ran, Z. Wen, L. 2023 Cistanche tubulosa Alleviates Ischemic Stroke-Induced Blood-Brain Barrier Damage by Modulating Microglia-Mediated Neuroinflammation Journal of Ethnopharmacology 309 116269 ID 10.1016/j.jep.2023.116269 36863639 Wu, C., Lin, H. and Su, M. (2014) Reversal by Aqueous Extracts of Cistanche tubulosa from Behavioral Deficits in Alzheimer’s Disease-Like Rat Model: Relevance for Amyloid Deposition and Central Neurotransmitter Function. BMCComplementaryandAlternativeMedicine, 14, Article No. 202. https://doi.org/10.1186/1472-6882-14-202 10.1186/1472-6882-14-20224968859https://doi.org/10.1186/1472-6882-14-202 Wu, C. Lin, H. Su, M. 2014 Reversal by Aqueous Extracts of Cistanche tubulosa from Behavioral Deficits in Alzheimer’s Disease-Like Rat Model: Relevance for Amyloid Deposition and Central Neurotransmitter Function BMC Complementary and Alternative Medicine 14 No 10.1186/1472-6882-14-202 24968859 Karran, E., Mercken, M. and Strooper, B.D. (2011) The Amyloid Cascade Hypothesis for Alzheimer’s Disease: An Appraisal for the Development of Therapeutics. NatureReviewsDrugDiscovery, 10, 698-712. https://doi.org/10.1038/nrd3505 10.1038/nrd350521852788https://doi.org/10.1038/nrd3505 Karran, E. Mercken, M. Strooper, B.D. 2011 The Amyloid Cascade Hypothesis for Alzheimer’s Disease: An Appraisal for the Development of Therapeutics Nature Reviews Drug Discovery 10 10.1038/nrd3505 21852788 Wilkins, H.M. and Swerdlow, R.H. (2017) Amyloid Precursor Protein Processing and Bioenergetics. BrainResearchBulletin, 133, 71-79. https://doi.org/10.1016/j.brainresbull.2016.08.009 10.1016/j.brainresbull.2016.08.00927545490https://doi.org/10.1016/j.brainresbull.2016.08.009 Wilkins, H.M. Swerdlow, R.H. 2017 Amyloid Precursor Protein Processing and Bioenergetics Brain Research Bulletin 133 10.1016/j.brainresbull.2016.08.009 27545490 Ricciarelli, R. and Fedele, E. (2017) The Amyloid Cascade Hypothesis in Alzheimer’s Disease: It’s Time to Change Our Mind. CurrentNeuropharmacology, 15, 926-935. https://doi.org/10.2174/1570159x15666170116143743 10.2174/1570159x1566617011614374328093977https://doi.org/10.2174/1570159x15666170116143743 Ricciarelli, R. Fedele, E. 2017 The Amyloid Cascade Hypothesis in Alzheimer’s Disease: It’s Time to Change Our Mind Current Neuropharmacology 15 10.2174/1570159x15666170116143743 28093977 Pritam, P., Deka, R., Bhardwaj, A., Srivastava, R., Kumar, D., Jha, A.K., et al. (2022) Antioxidants in Alzheimer’s Disease: Current Therapeutic Significance and Future Prospects. Biology, 11, Article 212. https://doi.org/10.3390/biology11020212 10.3390/biology1102021235205079https://doi.org/10.3390/biology11020212 Pritam, P. Deka, R. Bhardwaj, A. Srivastava, R. Kumar, D. Jha, A.K. 2022 Antioxidants in Alzheimer’s Disease: Current Therapeutic Significance and Future Prospects Biology 11 212 10.3390/biology11020212 35205079 Halliwell, B. (2006) Oxidative Stress and Neurodegeneration: Where Are We Now? JournalofNeurochemistry, 97, 1634-1658. https://doi.org/10.1111/j.1471-4159.2006.03907.x 10.1111/j.1471-4159.2006.03907.x16805774https://doi.org/10.1111/j.1471-4159.2006.03907.x Halliwell, B. 2006 Oxidative Stress and Neurodegeneration: Where Are We Now? Journal of Neurochemistry, 97, 1634-1658 10.1111/j.1471-4159.2006.03907.x 16805774 Varadarajan, S., Yatin, S., Aksenova, M. and Butterfield, D.A. (2000) Review: Alzheimer’s Amyloid β-Peptide-Associated Free Radical Oxidative Stress and Neurotoxicity. JournalofStructuralBiology, 130, 184-208. https://doi.org/10.1006/jsbi.2000.4274 10.1006/jsbi.2000.427410940225https://doi.org/10.1006/jsbi.2000.4274 Varadarajan, S. Yatin, S. Aksenova, M. Butterfield, D.A. 2000 Review: Alzheimer’s Amyloid β-Peptide-Associated Free Radical Oxidative Stress and Neurotoxicity Journal of Structural Biology 130 10.1006/jsbi.2000.4274 10940225 Tamagno, E., Parola, M., Guglielmotto, M., et al. (2003) Multiple Signaling Events in Amyloid β-Induced, Oxidative Stress-Dependent Neuronal Apoptosis. FreeRadicalBiologyandMedicine, 35, 45-58. https://doi.org/10.1016/s0891-5849(03)00244-2 10.1016/s0891-5849(03)00244-212826255https://doi.org/10.1016/s0891-5849(03)00244-2 Tamagno, E. Parola, M. Guglielmotto, M. Induced, O 2003 Multiple Signaling Events in Amyloid β-Induced, Oxidative Stress-Dependent Neuronal Apoptosis Free Radical Biology and Medicine 5849 03 10.1016/s0891-5849(03)00244-2 12826255 Roy, R.G., Mandal, P.K. and Maroon, J.C. (2023) Oxidative Stress Occurs Prior to Amyloid A β Plaque Formation and Tau Phosphorylation in Alzheimer’s Disease: Role of Glutathione and Metal Ions. ACSChemicalNeuroscience, 14, 2944-2954. https://doi.org/10.1021/acschemneuro.3c00486 10.1021/acschemneuro.3c0048637561556https://doi.org/10.1021/acschemneuro.3c00486 Roy, R.G. Mandal, P.K. Maroon, J.C. 2023 Oxidative Stress Occurs Prior to Amyloid Aβ Plaque Formation and Tau Phosphorylation in Alzheimer’s Disease: Role of Glutathione and Metal Ions ACS Chemical Neuroscience 14 10.1021/acschemneuro.3c00486 37561556 Kamaljeet, Singh, S., Gupta, G.D. and Aran, K.R. (2024) Emerging Role of Antioxidants in Alzheimer’s Disease: Insight into Physiological, Pathological Mechanisms and Management. PharmaceuticalScienceAdvances, 2, Article ID: 100021. https://doi.org/10.1016/j.pscia.2023.100021 10.1016/j.pscia.2023.100021https://doi.org/10.1016/j.pscia.2023.100021 Kamaljeet, S Gupta, G.D. Aran, K.R. Physiological, P 2024 Emerging Role of Antioxidants in Alzheimer’s Disease: Insight into Physiological, Pathological Mechanisms and Management Pharmaceutical Science Advances 2 100021 ID 10.1016/j.pscia.2023.100021 Chinese Pharmacopoeia Commission and State Pharmacopoeia Commission (2015) Pharmacopoeia of the People’s Republic of China 2015. China Medical Science Press. 2015 Pharmacopoeia of the People’s Republic of China 2015 Li, Z., Lin, H., Gu, L., Gao, J. and Tzeng, C. (2016) Herba Cistanche (Rou Cong-Rong): One of the Best Pharmaceutical Gifts of Traditional Chinese Medicine. FrontiersinPharmacology, 7, Article 41. https://doi.org/10.3389/fphar.2016.00041 10.3389/fphar.2016.0004126973528https://doi.org/10.3389/fphar.2016.00041 Li, Z. Lin, H. Gu, L. Gao, J. Tzeng, C. 2016 Herba Cistanche (Rou Cong-Rong): One of the Best Pharmaceutical Gifts of Traditional Chinese Medicine Frontiers in Pharmacology 7 41 10.3389/fphar.2016.00041 26973528 Morikawa, T., Pan, Y., Ninomiya, K., Imura, K., Yuan, D., Yoshikawa, M., et al. (2010) Iridoid and Acyclic Monoterpene Glycosides, Kankanosides L, M, N, O, and P from Cistanche tubulosa. ChemicalandPharmaceuticalBulletin, 58, 1403-1407. https://doi.org/10.1248/cpb.58.1403 10.1248/cpb.58.140320930413https://doi.org/10.1248/cpb.58.1403 Morikawa, T. Pan, Y. Ninomiya, K. Imura, K. Yuan, D. Yoshikawa, M. Glycosides, K 2010 Iridoid and Acyclic Monoterpene Glycosides, Kankanosides L, M, N, O, and P from Cistanche tubulosa Chemical and Pharmaceutical Bulletin 58 10.1248/cpb.58.1403 20930413 Yoshikawa, M., Matsuda, H., Morikawa, T., Xie, H., Nakamura, S. and Muraoka, O. (2006) Phenylethanoid Oligoglycosides and Acylated Oligosugars with Vasorelaxant Activity from Cistanche tubulosa. Bioorganic&MedicinalChemistry, 14, 7468-7475. https://doi.org/10.1016/j.bmc.2006.07.018 10.1016/j.bmc.2006.07.01816908167https://doi.org/10.1016/j.bmc.2006.07.018 Yoshikawa, M. Matsuda, H. Morikawa, T. Xie, H. Nakamura, S. Muraoka, O. 2006 Phenylethanoid Oligoglycosides and Acylated Oligosugars with Vasorelaxant Activity from Cistanche tubulosa Bioorganic & Medicinal Chemistry 14 10.1016/j.bmc.2006.07.018 16908167 Guo, Q., Zhou, Y., Wang, C., Huang, Y., Lee, Y., Su, M., et al. (2013) An Open-Label, Nonplacebo-Controlled Study on Cistanche tubulosa Glycoside Capsules (Memoregain ®) for Treating Moderate Alzheimer’s Disease. AmericanJournalofAlzheimer’sDisease&OtherDementias®, 28, 363-370. https://doi.org/10.1177/1533317513488907 10.1177/153331751348890723687177https://doi.org/10.1177/1533317513488907 Guo, Q. Zhou, Y. Wang, C. Huang, Y. Lee, Y. Su, M. Open-Label, N 2013 An Open-Label, Nonplacebo-Controlled Study on Cistanche tubulosa Glycoside Capsules (Memoregain®) for Treating Moderate Alzheimer’s Disease American Journal of Alzheimer’s Disease & Other Dementias® 28 10.1177/1533317513488907 23687177 Ji, S., Wu, Y., Zhu, R., Guo, D., Jiang, Y., Huang, L., et al. (2023) Novel Phenylethanoid Glycosides Improve Hippocampal Synaptic Plasticity via the Cyclic Adenosine Monophosphate-CREB-Brain-Derived Neurotrophic Growth Factor Pathway in APP/PS1 Transgenic Mice. Gerontology, 69, 1065-1075. https://doi.org/10.1159/000531194 10.1159/00053119437285833https://doi.org/10.1159/000531194 Ji, S. Wu, Y. Zhu, R. Guo, D. Jiang, Y. Huang, L. 2023 Novel Phenylethanoid Glycosides Improve Hippocampal Synaptic Plasticity via the Cyclic Adenosine Monophosphate-CREB-Brain-Derived Neurotrophic Growth Factor Pathway in APP/PS1 Transgenic Mice Gerontology 69 10.1159/000531194 37285833 Wu, L., Georgiev, M.I., Cao, H., Nahar, L., El‐Seedi, H.R., Sarker, S.D., et al. (2020) Therapeutic Potential of Phenylethanoid Glycosides: A Systematic Review. MedicinalResearchReviews, 40, 2605-2649. https://doi.org/10.1002/med.21717 10.1002/med.2171732779240https://doi.org/10.1002/med.21717 Wu, L. Georgiev, M.I. Cao, H. Nahar, L. Seedi, H.R. Sarker, S.D. 2020 Therapeutic Potential of Phenylethanoid Glycosides: A Systematic Review Medicinal Research Reviews 40 10.1002/med.21717 32779240 Yang, J., Ju, B., Yan, Y., Xu, H., Wu, S., Zhu, D., et al. (2017) Neuroprotective Effects of Phenylethanoid Glycosides in an in Vitro Model of Alzheimer’s Disease. ExperimentalandTherapeuticMedicine, 13, 2423-2428. https://doi.org/10.3892/etm.2017.4254 10.3892/etm.2017.425428565858https://doi.org/10.3892/etm.2017.4254 Yang, J. Ju, B. Yan, Y. Xu, H. Wu, S. Zhu, D. 2017 Neuroprotective Effects of Phenylethanoid Glycosides in an in Vitro Model of Alzheimer’s Disease Experimental and Therapeutic Medicine 13 10.3892/etm.2017.4254 28565858 Morikawa, T., Ninomiya, K., Imamura, M., Akaki, J., Fujikura, S., Pan, Y., et al. (2014) Acylated Phenylethanoid Glycosides, Echinacoside and Acteoside from Cistanche tubulosa, Improve Glucose Tolerance in Mice. JournalofNaturalMedicines, 68, 561-566. https://doi.org/10.1007/s11418-014-0837-9 10.1007/s11418-014-0837-924748124https://doi.org/10.1007/s11418-014-0837-9 Morikawa, T. Ninomiya, K. Imamura, M. Akaki, J. Fujikura, S. Pan, Y. Glycosides, E 2014 Acylated Phenylethanoid Glycosides, Echinacoside and Acteoside from Cistanche tubulosa, Improve Glucose Tolerance in Mice Journal of Natural Medicines 68 10.1007/s11418-014-0837-9 24748124 Xie, H., Morikawa, T., Matsuda, H., Nakamura, S., Muraoka, O. and Yoshikawa, M. (2006) Monoterpene Constituents from Cistanche tubulosa-Chemical Structures of Kankanosides A-E and Kankanol. ChemicalandPharmaceuticalBulletin, 54, 669-675. https://doi.org/10.1248/cpb.54.669 10.1248/cpb.54.66916651763https://doi.org/10.1248/cpb.54.669 Xie, H. Morikawa, T. Matsuda, H. Nakamura, S. Muraoka, O. Yoshikawa, M. 2006 Monoterpene Constituents from Cistanche tubulosa-Chemical Structures of Kankanosides A-E and Kankanol Chemical and Pharmaceutical Bulletin 54 10.1248/cpb.54.669 16651763 Li, J., Yu, H., Yang, C., Ma, T. and Dai, Y. (2022) Therapeutic Potential and Molecular Mechanisms of Echinacoside in Neurodegenerative Diseases. FrontiersinPharmacology, 13, Article 841110. https://doi.org/10.3389/fphar.2022.841110 10.3389/fphar.2022.84111035185590https://doi.org/10.3389/fphar.2022.841110 Li, J. Yu, H. Yang, C. Ma, T. Dai, Y. 2022 Therapeutic Potential and Molecular Mechanisms of Echinacoside in Neurodegenerative Diseases Frontiers in Pharmacology 13 841110 10.3389/fphar.2022.841110 35185590 Shiao, Y., Su, M., Lin, H. and Wu, C. (2017) Echinacoside Ameliorates the Memory Impairment and Cholinergic Deficit Induced by Amyloid Beta Peptides via the Inhibition of Amyloid Deposition and Toxicology. Food&Function, 8, 2283-2294. https://doi.org/10.1039/c7fo00267j 10.1039/c7fo00267j28581010https://doi.org/10.1039/c7fo00267j Shiao, Y. Su, M. Lin, H. Wu, C. 2017 Echinacoside Ameliorates the Memory Impairment and Cholinergic Deficit Induced by Amyloid Beta Peptides via the Inhibition of Amyloid Deposition and Toxicology Food & Function 8 10.1039/c7fo00267j 28581010 Xiao, Y., Ren, Q. and Wu, L. (2022) The Pharmacokinetic Property and Pharmacological Activity of Acteoside: A Review. Biomedicine&Pharmacotherapy, 153, 113296. https://doi.org/10.1016/j.biopha.2022.113296 10.1016/j.biopha.2022.11329635724511https://doi.org/10.1016/j.biopha.2022.113296 Xiao, Y. Ren, Q. Wu, L. 2022 The Pharmacokinetic Property and Pharmacological Activity of Acteoside: A Review Biomedicine & Pharmacotherapy 153 10.1016/j.biopha.2022.113296 35724511 Ji, S., Cao, K., Zhao, X., Kang, N., Zhang, Y., Xu, Q., et al. (2019) Antioxidant Activity of Phenylethanoid Glycosides on Glutamate-Induced Neurotoxicity. Bioscience, Biotechnology, andBiochemistry, 83, 2016-2026. https://doi.org/10.1080/09168451.2019.1637243 10.1080/09168451.2019.163724331272310https://doi.org/10.1080/09168451.2019.1637243 Ji, S. Cao, K. Zhao, X. Kang, N. Zhang, Y. Xu, Q. Bioscience, B 2019 Antioxidant Activity of Phenylethanoid Glycosides on Glutamate-Induced Neurotoxicity Bioscience 83 10.1080/09168451.2019.1637243 31272310 Wang, H., Sun, Y., Ye, W., Xiong, F., Wu, J., Yang, C., et al. (2004) Antioxidative Phenylethanoid and Phenolic Glycosides from Picrorhiza scrophulariiflora. ChemicalandPharmaceuticalBulletin, 52, 615-617. https://doi.org/10.1248/cpb.52.615 10.1248/cpb.52.61515133218https://doi.org/10.1248/cpb.52.615 Wang, H. Sun, Y. Ye, W. Xiong, F. Wu, J. Yang, C. 2004 Antioxidative Phenylethanoid and Phenolic Glycosides from Picrorhiza scrophulariiflora Chemical and Pharmaceutical Bulletin 52 10.1248/cpb.52.615 15133218 Hong, Y. (2010) Antioxidant Activity of Extracts from Desertliving Cistanche tubulosa (Schrenk) R. Wright. Shanghai Journal of Traditional Chinese Medicine, 41, 75-78. Hong, Y. 2010 Antioxidant Activity of Extracts from Desertliving Cistanche tubulosa (Schrenk) R Wright. Shanghai Journal of Traditional Chinese Medicine 41 Gu, C., Yang, X. and Huang, L. (2016) Cistanches herba: A Neuropharmacology Review. FrontiersinPharmacology, 7, Article 289. https://doi.org/10.3389/fphar.2016.00289 10.3389/fphar.2016.0028927703431https://doi.org/10.3389/fphar.2016.00289 Gu, C. Yang, X. Huang, L. 2016 Cistanches herba: A Neuropharmacology Review Frontiers in Pharmacology 7 289 10.3389/fphar.2016.00289 27703431 Choi, J.G., Moon, M., Jeong, H.U., Kim, M.C., Kim, S.Y. and Oh, M.S. (2011) Cistanches Herba Enhances Learning and Memory by Inducing Nerve Growth Factor. BehaviouralBrainResearch, 216, 652-658. https://doi.org/10.1016/j.bbr.2010.09.008 10.1016/j.bbr.2010.09.00820849880https://doi.org/10.1016/j.bbr.2010.09.008 Choi, J.G. Moon, M. Jeong, H.U. Kim, M.C. Kim, S.Y. Oh, M.S. 2011 Cistanches Herba Enhances Learning and Memory by Inducing Nerve Growth Factor Behavioural Brain Research 216 10.1016/j.bbr.2010.09.008 20849880 Chao, C.L,. Huang, H.W., Huang, H.C., et al. (2019) Inhibition of Amyloid β Aggregation and Deposition of Cistanche tubulosa Aqueous Extract. Molecules, 24, Article 687. Chao, C.L Huang, H.W. Huang, H.C. 2019 Inhibition of Amyloid β Aggregation and Deposition of Cistanche tubulosa Aqueous Extract Molecules 24 687 Drummond, E. and Wisniewski, T. (2016) Alzheimer’s Disease: Experimental Models and Reality. ActaNeuropathologica, 133, 155-175. https://doi.org/10.1007/s00401-016-1662-x 10.1007/s00401-016-1662-x28025715https://doi.org/10.1007/s00401-016-1662-x Drummond, E. Wisniewski, T. 2016 Alzheimer’s Disease: Experimental Models and Reality Acta Neuropathologica 133 10.1007/s00401-016-1662-x 28025715 Lin, J., Gao, S., Wang, T., et al. (2019) Ginsenoside Rb1 Improves Learning and Memory Ability through Its Anti-Inflammatory Effect in A β(1-40)-Induced Alzheimer’s Disease of Rats. American Journal of Translational Research, 11, 2955-2968. Lin, J. Gao, S. Wang, T. 2019 Ginsenoside Rb1 Improves Learning and Memory Ability through Its Anti-Inflammatory Effect in Aβ(1-40)-Induced Alzheimer’s Disease of Rats American Journal of Translational Research 11 Qiu, H. and Liu, X. (2022) Echinacoside Improves Cognitive Impairment by Inhibiting A β Deposition through the PI3K/AKT/Nrf2/PPAR γ Signaling Pathways in APP/PS1 Mice. MolecularNeurobiology, 59, 4987-4999. https://doi.org/10.1007/s12035-022-02885-5 10.1007/s12035-022-02885-535665898https://doi.org/10.1007/s12035-022-02885-5 Qiu, H. Liu, X. 2022 Echinacoside Improves Cognitive Impairment by Inhibiting Aβ Deposition through the PI3K/AKT/Nrf2/PPARγ Signaling Pathways in APP/PS1 Mice Molecular Neurobiology 59 10.1007/s12035-022-02885-5 35665898 Dass, P.D., Offutt, D.M., Mejia, M.B., et al. (1997) Comparative Kinetic Analysis of Cholinesterase Methods in Rat and Human Erythrocytes and Plasma. Veterinary and Human Toxicology, 39, 11-17. Dass, P.D. Offutt, D.M. Mejia, M.B. 1997 Comparative Kinetic Analysis of Cholinesterase Methods in Rat and Human Erythrocytes and Plasma Veterinary and Human Toxicology 39 Friedman, E., Lerer, B. and Kuster, J. (1983) Loss of Cholinergic Neurons in the Rat Neocortex Produces Deficits in Passive Avoidance Learning. PharmacologyBiochemistryandBehavior, 19, 309-312. https://doi.org/10.1016/0091-3057(83)90057-6 10.1016/0091-3057(83)90057-66634880https://doi.org/10.1016/0091-3057(83)90057-6 Friedman, E. Lerer, B. Kuster, J. 1983 Loss of Cholinergic Neurons in the Rat Neocortex Produces Deficits in Passive Avoidance Learning Pharmacology Biochemistry and Behavior 3057 83 10.1016/0091-3057(83)90057-6 6634880 Yamaguchi, Y., Miyashita, H., Tsunekawa, H., Mouri, A., Kim, H., Saito, K., et al. (2006) Effects of a Novel Cognitive Enhancer, Spiro[Imidazo-[1,2-A]Pyridine-3,2-Indan]-2(3 H)-One (ZSET1446), on Learning Impairments Induced by Amyloid- Β1–40 in the Rat. TheJournalofPharmacologyandExperimentalTherapeutics, 317, 1079-1087. https://doi.org/10.1124/jpet.105.098640 10.1124/jpet.105.09864016474004https://doi.org/10.1124/jpet.105.098640 Yamaguchi, Y. Miyashita, H. Tsunekawa, H. Mouri, A. Kim, H. Saito, K. Enhancer, S 2006 Effects of a Novel Cognitive Enhancer, Spiro[Imidazo-[1,2-A]Pyridine-3,2-Indan]-2(3 H)-One (ZSET1446), on Learning Impairments Induced by Amyloid-Β1–40 in the Rat The Journal of Pharmacology and Experimental Therapeutics 317 10.1124/jpet.105.098640 16474004 Hansson, O., Blennow, K., Zetterberg, H. and Dage, J. (2023) Blood Biomarkers for Alzheimer’s Disease in Clinical Practice and Trials. NatureAging, 3, 506-519. https://doi.org/10.1038/s43587-023-00403-3 10.1038/s43587-023-00403-337202517https://doi.org/10.1038/s43587-023-00403-3 Hansson, O. Blennow, K. Zetterberg, H. Dage, J. 2023 Blood Biomarkers for Alzheimer’s Disease in Clinical Practice and Trials Nature Aging 3 10.1038/s43587-023-00403-3 37202517 Ighodaro, O.M. and Akinloye, O.A. (2018) First Line Defence Antioxidants-Superoxide Dismutase (SOD), Catalase (CAT) and Glutathione Peroxidase (GPX): Their Fundamental Role in the Entire Antioxidant Defence Grid. AlexandriaJournalofMedicine, 54, 287-293. https://doi.org/10.1016/j.ajme.2017.09.001 10.1016/j.ajme.2017.09.001https://doi.org/10.1016/j.ajme.2017.09.001 Ighodaro, O.M. Akinloye, O.A. 2018 First Line Defence Antioxidants-Superoxide Dismutase (SOD), Catalase (CAT) and Glutathione Peroxidase (GPX): Their Fundamental Role in the Entire Antioxidant Defence Grid Alexandria Journal of Medicine 54 10.1016/j.ajme.2017.09.001 Nordberg, A., Ballard, C., Bullock, R., Darreh-Shori, T. and Somogyi, M. (2013) A Review of Butyrylcholinesterase as a Therapeutic Target in the Treatment of Alzheimer’s Disease. ThePrimaryCareCompanionforCNSDisorders, 15, e1-e6. https://doi.org/10.4088/pcc.12r01412 10.4088/pcc.12r0141223930233https://doi.org/10.4088/pcc.12r01412 Nordberg, A. Ballard, C. Bullock, R. Darreh-Shori, T. Somogyi, M. 2013 A Review of Butyrylcholinesterase as a Therapeutic Target in the Treatment of Alzheimer’s Disease The Primary Care Companion for CNS Disorders 15 10.4088/pcc.12r01412 23930233 Duarte, A.I., Candeias, E., Alves, I.N., Mena, D., Silva, D.F., Machado, N.J., et al. (2020) Liraglutide Protects against Brain Amyloid- Β1-42 Accumulation in Female Mice with Early Alzheimer’s Disease-Like Pathology by Partially Rescuing Oxidative/nitrosative Stress and Inflammation. InternationalJournalofMolecularSciences, 21, Article 1746. https://doi.org/10.3390/ijms21051746 10.3390/ijms2105174632143329https://doi.org/10.3390/ijms21051746 Duarte, A.I. Candeias, E. Alves, I.N. Mena, D. Silva, D.F. Machado, N.J. 2020 Liraglutide Protects against Brain Amyloid-Β1-42 Accumulation in Female Mice with Early Alzheimer’s Disease-Like Pathology by Partially Rescuing Oxidative/nitrosative Stress and Inflammation International Journal of Molecular Sciences 21 1746 10.3390/ijms21051746 32143329 Clark, D.O., Xu, H., Moser, L., Adeoye, P., Lin, A.W., Tangney, C.C., et al. (2019) MIND Food and Speed of Processing Training in Older Adults with Low Education, the Mindspeed Alzheimer’s Disease Prevention Pilot Trial. ContemporaryClinicalTrials, 84, Article ID: 105814. https://doi.org/10.1016/j.cct.2019.105814 10.1016/j.cct.2019.10581431326523https://doi.org/10.1016/j.cct.2019.105814 Clark, D.O. Xu, H. Moser, L. Adeoye, P. Lin, A.W. Tangney, C.C. 2019 MIND Food and Speed of Processing Training in Older Adults with Low Education, the Mindspeed Alzheimer’s Disease Prevention Pilot Trial Contemporary Clinical Trials 84 105814 ID 10.1016/j.cct.2019.105814 31326523 Mohamed, W.A., Salama, R.M. and Schaalan, M.F. (2019) A Pilot Study on the Effect of Lactoferrin on Alzheimer’s Disease Pathological Sequelae: Impact of the P-Akt/PTEN Pathway. Biomedicine&Pharmacotherapy, 111, 714-723. https://doi.org/10.1016/j.biopha.2018.12.118 10.1016/j.biopha.2018.12.11830611996https://doi.org/10.1016/j.biopha.2018.12.118 Mohamed, W.A. Salama, R.M. Schaalan, M.F. 2019 A Pilot Study on the Effect of Lactoferrin on Alzheimer’s Disease Pathological Sequelae: Impact of the P-Akt/PTEN Pathway Biomedicine & Pharmacotherapy 111 10.1016/j.biopha.2018.12.118 30611996 Saini, N., Kadian, M., Khera, A., etal. (2021) Therapeutic Potential of Allium Sativum against the A β((1-40))-Induced Oxidative Stress and Mitochondrial Dysfunction in the Wistar Rats. American Journal of Neurodegenerative Disease, 10, 13-27. Saini, N. Kadian, M. Khera, A. 2021 Therapeutic Potential of Allium Sativum against the Aβ((1-40))-Induced Oxidative Stress and Mitochondrial Dysfunction in the Wistar Rats American Journal of Neurodegenerative Disease 10 Ghofrani, S., Joghataei, M., Mohseni, S., Baluchnejadmojarad, T., Bagheri, M., Khamse, S., et al. (2015) Naringenin Improves Learning and Memory in an Alzheimer’s Disease Rat Model: Insights into the Underlying Mechanisms. EuropeanJournalofPharmacology, 764, 195-201. https://doi.org/10.1016/j.ejphar.2015.07.001 10.1016/j.ejphar.2015.07.00126148826https://doi.org/10.1016/j.ejphar.2015.07.001 Ghofrani, S. Joghataei, M. Mohseni, S. Baluchnejadmojarad, T. Bagheri, M. Khamse, S. 2015 Naringenin Improves Learning and Memory in an Alzheimer’s Disease Rat Model: Insights into the Underlying Mechanisms European Journal of Pharmacology 764 10.1016/j.ejphar.2015.07.001 26148826 Resende, R., Moreira, P.I., Proença, T., Deshpande, A., Busciglio, J., Pereira, C., et al. (2008) Brain Oxidative Stress in a Triple-Transgenic Mouse Model of Alzheimer Disease. FreeRadicalBiologyandMedicine, 44, 2051-2057. https://doi.org/10.1016/j.freeradbiomed.2008.03.012 10.1016/j.freeradbiomed.2008.03.01218423383https://doi.org/10.1016/j.freeradbiomed.2008.03.012 Resende, R. Moreira, P.I. Deshpande, A. Busciglio, J. Pereira, C. 2008 Brain Oxidative Stress in a Triple-Transgenic Mouse Model of Alzheimer Disease Free Radical Biology and Medicine 44 10.1016/j.freeradbiomed.2008.03.012 18423383 Ghasemi-Tarie, R., Kiasalari, Z., Fakour, M., Khorasani, M., Keshtkar, S., Baluchnejadmojarad, T., et al. (2022) Nobiletin Prevents Amyloid Β1-40-Induced Cognitive Impairment via Inhibition of Neuroinflammation and Oxidative/nitrosative Stress. MetabolicBrainDisease, 37, 1337-1349. https://doi.org/10.1007/s11011-022-00949-y 10.1007/s11011-022-00949-y35294678https://doi.org/10.1007/s11011-022-00949-y Ghasemi-Tarie, R. Kiasalari, Z. Fakour, M. Khorasani, M. Keshtkar, S. Baluchnejadmojarad, T. 2022 Nobiletin Prevents Amyloid Β1-40-Induced Cognitive Impairment via Inhibition of Neuroinflammation and Oxidative/nitrosative Stress Metabolic Brain Disease 37 10.1007/s11011-022-00949-y 35294678 Dhapola, R., Beura, S.K., Sharma, P., Singh, S.K. and HariKrishnaReddy, D. (2024) Oxidative Stress in Alzheimer’s Disease: Current Knowledge of Signaling Pathways and Therapeutics. MolecularBiologyReports, 51, Article No. 48. https://doi.org/10.1007/s11033-023-09021-z 10.1007/s11033-023-09021-z38165499https://doi.org/10.1007/s11033-023-09021-z Dhapola, R. Beura, S.K. Sharma, P. Singh, S.K. HariKrishnaReddy, D. 2024 Oxidative Stress in Alzheimer’s Disease: Current Knowledge of Signaling Pathways and Therapeutics Molecular Biology Reports 51 No 10.1007/s11033-023-09021-z 38165499 Tönnies, E. and Trushina, E. (2017) Oxidative Stress, Synaptic Dysfunction, and Alzheimer’s Disease. JournalofAlzheimer’sDisease, 57, 1105-1121. https://doi.org/10.3233/jad-161088 10.3233/jad-16108828059794https://doi.org/10.3233/jad-161088 Trushina, E. Stress, S 2017 Oxidative Stress, Synaptic Dysfunction, and Alzheimer’s Disease Journal of Alzheimer’s Disease 57 10.3233/jad-161088 28059794 Namba, Y., Tomonaga, M., Kawasaki, H., Otomo, E. and Ikeda, K. (1991) Apolipoprotein E Immunoreactivity in Cerebral Amyloid Deposits and Neurofibrillary Tangles in Alzheimer’s Disease and Kuru Plaque Amyloid in Creutzfeldt-Jakob Disease. BrainResearch, 541, 163-166. https://doi.org/10.1016/0006-8993(91)91092-f 10.1016/0006-8993(91)91092-f2029618https://doi.org/10.1016/0006-8993(91)91092-f Namba, Y. Tomonaga, M. Kawasaki, H. Otomo, E. Ikeda, K. 1991 Apolipoprotein E Immunoreactivity in Cerebral Amyloid Deposits and Neurofibrillary Tangles in Alzheimer’s Disease and Kuru Plaque Amyloid in Creutzfeldt-Jakob Disease Brain Research 8993 91 10.1016/0006-8993(91)91092-f 2029618 Markesbery, W.R., Kryscio, R.J., Lovell, M.A. and Morrow, J.D. (2005) Lipid Peroxidation Is an Early Event in the Brain in Amnestic Mild Cognitive Impairment. AnnalsofNeurology, 58, 730-735. https://doi.org/10.1002/ana.20629 10.1002/ana.2062916240347https://doi.org/10.1002/ana.20629 Markesbery, W.R. Kryscio, R.J. Lovell, M.A. Morrow, J.D. 2005 Lipid Peroxidation Is an Early Event in the Brain in Amnestic Mild Cognitive Impairment Annals of Neurology 58 10.1002/ana.20629 16240347 Igbavboa, U., Hamilton, J., Kim, H., Sun, G.Y. and Wood, W.G. (2002) A New Role for Apolipoprotein E: Modulating Transport of Polyunsaturated Phospholipid Molecular Species in Synaptic Plasma Membranes. JournalofNeurochemistry, 80, 255-261. https://doi.org/10.1046/j.0022-3042.2001.00688.x 10.1046/j.0022-3042.2001.00688.x11902115https://doi.org/10.1046/j.0022-3042.2001.00688.x Igbavboa, U. Hamilton, J. Kim, H. Sun, G.Y. Wood, W.G. 2002 A New Role for Apolipoprotein E: Modulating Transport of Polyunsaturated Phospholipid Molecular Species in Synaptic Plasma Membranes Journal of Neurochemistry 80 10.1046/j.0022-3042.2001.00688.x 11902115 Butterfield, D.A. and Mattson, M.P. (2020) Apolipoprotein E and Oxidative Stress in Brain with Relevance to Alzheimer’s Disease. NeurobiologyofDisease, 138, 104795. https://doi.org/10.1016/j.nbd.2020.104795 10.1016/j.nbd.2020.10479532036033https://doi.org/10.1016/j.nbd.2020.104795 Butterfield, D.A. Mattson, M.P. 2020 Apolipoprotein E and Oxidative Stress in Brain with Relevance to Alzheimer’s Disease Neurobiology of Disease 138 10.1016/j.nbd.2020.104795 32036033 Liu, J., Fan, Y., Yang, Z., Wang, Z. and Guo, C. (2018) Iron and Alzheimer’s Disease: From Pathogenesis to Therapeutic Implications. FrontiersinNeuroscience, 12, Article 632. https://doi.org/10.3389/fnins.2018.00632 10.3389/fnins.2018.0063230250423https://doi.org/10.3389/fnins.2018.00632 Liu, J. Fan, Y. Yang, Z. Wang, Z. Guo, C. 2018 Iron and Alzheimer’s Disease: From Pathogenesis to Therapeutic Implications Frontiers in Neuroscience 12 632 10.3389/fnins.2018.00632 30250423 Everett, J., Céspedes, E., Shelford, L.R., Exley, C., Collingwood, J.F., Dobson, J., et al. (2014) Ferrous Iron Formation Following the Co-Aggregation of Ferric Iron and the Alzheimer’s Disease Peptide β-Amyloid (1-42). JournaloftheRoyalSocietyInterface, 11, Article ID: 20140165. https://doi.org/10.1098/rsif.2014.0165 10.1098/rsif.2014.016524671940https://doi.org/10.1098/rsif.2014.0165 Everett, J. Shelford, L.R. Exley, C. Collingwood, J.F. Dobson, J. 2014 Ferrous Iron Formation Following the Co-Aggregation of Ferric Iron and the Alzheimer’s Disease Peptide β-Amyloid (1-42) Journal of the Royal Society Interface 11 201401 ID 10.1098/rsif.2014.0165 24671940 Dixon, S.J. (2017) Ferroptosis: Bug or Feature? ImmunologicalReviews, 277, 150-157. https://doi.org/10.1111/imr.12533 10.1111/imr.1253328462529https://doi.org/10.1111/imr.12533 Dixon, S.J. 2017 Ferroptosis: Bug or Feature? Immunological Reviews, 277, 150-157 10.1111/imr.12533 28462529