Fenugreek Seed Powder Nullified Aluminium Chloride Induced Memory Loss, Biochemical Changes, Aβ Burden and Apoptosis via Regulating Akt/GSK3β Signaling Pathway

Diabetes mellitus and Alzheimer's disease: Understanding disease mechanisms, their correlation, and promising dual activity of selected herbs

ETHNOPHARMACOLOGICAL RELEVANCE

This review explores the link between Type 2 Diabetes Mellitus (T2DM) and diabetes-induced Alzheimer's disease (AD). It emphasizes the shared pathophysiological links and mechanisms between the two conditions, focusing on reduced insulin levels and receptors, impaired glucose metabolism, insulin resistance, mitochondrial dysfunction, and oxidative damage in AD-affected brains-paralleling aspects of T2DM. The review suggests AD as a "diabetes of the brain," supported by cognitive enhancement through antidiabetic interventions. It focuses on the traditionally used Indian herbs as a means to manage both conditions while addressing developmental challenges.

AIM OF THE STUDY

This study explores the DM-AD connection, reviewing medicinal herbs with protective potential for both ailments, considering traditional uses and developmental challenges.

MATERIALS AND METHODS

Studied research, reviews, and ethnobotanical and scientific data from electronic databases and traditional books.

RESULTS

The study analyzes the pathophysiological links between DM and AD, emphasizing their interconnected factors. Eight Ayurvedic plants with dual protective effects against T2DM and AD are thoroughly reviewed with preclinical/clinical evidence. Historical context, phytoconstituents, and traditional applications are explored. Innovative formulations using these plants are examined. Challenges stemming from phytoconstituents' physicochemical properties are highlighted, prompting novel formulation development, including nanotechnology-based delivery systems. The study uncovers obstacles in formulating treatments for these diseases.

CONCLUSION

The review showcases the dual potential of chosen medicinal herbs against both diseases, along with their traditional applications, endorsing their use. It addresses formulation obstacles, proposing innovative delivery technologies for herbal therapies, while acknowledging their constraints. The review suggests the need for heightened investment and research in this area.

Hippocampal mitochondrial Ca++ in experimentally induced Alzheimer's disease, link to calpains and impact of vitamin D3 supplementation

Vitamin D impact on hippocampal mitochondrial Ca++ and calpains was not previously investigated in Alzheimer's disease (AD). The current work aimed to assess the alteration in hippocampal mitochondrial Ca++, ATP & ADP and hippocampal calpains' level in (AlCl3)-induced AD model, and the effect of 2 regimens of vitamin D supplementation on these alterations.

METHODS

Forty male Wistar rats were randomized into 4 groups; control, AD (AlCl3100 mg/kg, p.o. daily for 42 days), AD and vitamin D co-treated group (AlCl3 as in AD group with vitamin D3 400 IU/kg/day, p.o. for 42 days) and AD, followed by vitamin D3 group (AlCl3 was given as in AD group for 42 days, then vitamin D3 for two weeks). AD was assessed by hippocampal levels of Aβ42, p-tau and spatial memory assessment in Morris water maze. Hippocampal mitochondrial Ca++, ATP and ADP levels besides to calpain-1 & 2 and cytochrome C were assessed in addition to CA1 histological examination.

RESULTS

AD animals showed impaired mitochondrial function as denoted by high Ca++ and decreased ATP and ADP and elevated calpain-1 & 2 and cytochrome C. Hippocampal CA1 region showed increased degenerated neurons and reduced thickness of its pyramidal layer. Vitamin D administration minimized the hippocampal mitochondrial impairement induced by AD and mitigated histological alterations even when supplemented post AD establishment.

CONCLUSION

Vitamin D administration to AD rats breaks the deleterious loop in the hippocampus that involves increased Ca++, calpain activation, mitochondrial failure, neuronal degeneration and AD disease progression.

Effects of aerobic exercise and dietary flavonoids on cognition: a systematic review and meta-analysis

Introduction: Studies have shown that exercise increases angiogenesis and perfusion in the hippocampus, activates neurogenesis in the dentate gyrus and increases synaptic plasticity, as well as increases the complexity and number of dendritic spines, all of which promote memory function and protect against cognitive decline. Flavonoids are gaining attention as antioxidants in health promotion due to their rich phenolic content, particularly for their modulating role in the treatment of neurodegenerative diseases. Despite this, there has been no comprehensive review of cognitive improvement supplemented with flavonoid and prescribed with exercise or a combination of the two interventions has been conducted. The purpose of this review is to determine whether a combined intervention produces better results when given together than when given separately. Methods: Relevant articles assessing the effect of physical exercise, flavonoid or in combination on cognitive related biomarkers and neurobehavioral assessments within the timeline of January 2011 until June 2023 were searched using three databases; PubMed, PROQUEST and SCOPUS. Results: A total of 705 articles were retrieved and screened, resulting in 108 studies which are in line with the objective of the current study were included in the analysis. Discussion: The selected studies have shown significant desired effect on the chosen biomarkers and neurobehavioral assessments. Systematic Review Registration: identifier: [CRD42021271001].

Fenugreek seed powder protects mice against arsenic-induced neurobehavioral changes

The current study was designed to evaluate the protective effect of fenugreek seed powder against As-induced neurobehavioral and biochemical perturbations using a mouse model. Mice exposed to arsenic at 10 mg/kg body weight showed development of anxiety-like behavior and memory impairment compared to control mice in elevated plus maze and Morris water maze tests, respectively. A significantly decreased acetyl and butyrylcholinesterase, superoxide dismutase and glutathione reductase activities and brain-derived neurotrophic factor levels were found in the brain of arsenic-exposed mice compared to control mice. Interestingly, supplementation of fenugreek seed powder to arsenic-treated mice significantly restored the activity of cholinesterase and antioxidant enzymes (e.g. superoxide dismutase, glutathione reductase) as well as brain-derived neurotrophic factor levels in the brain tissue of arsenic-exposed mice. Consequently, reduced anxiety-like behavior, improved learning and memory were observed in fenugreek supplemented arsenic treated mice compared to only arsenic-exposed mice group. Thus, this study suggests that fenugreek seed powder reduces arsenic-induced neurotoxicity in mice.

Assessment of Anti-Alzheimer Pursuit of Jambolan Fruit Extract and/or Choline against AlCl3 Toxicity in Rats

Jambolan fruit extract and choline were investigated for Aluminum tri chloride (AlCl₃)-induced Alzheimer's disease in rats. Thirty-six male "Sprague Dawley" rats weighing (150 ± 10 g) were allocated into six groups; the first group was fed a baseline diet and served as a negative control. Alzheimer's disease (AD) was induced in Group 2 rats by oral administration of AlCl₃ (17 mg/kg body weight) dissolved in distilled water (served as a positive control). Rats in Group 3 were orally supplemented concomitantly with both 500 mg/kg BW of an ethanolic extract of jambolan fruit once daily for 28 days and AlCl₃ (17 mg/kg body weight). Group 4: Rivastigmine (RIVA) aqueous infusion (0.3 mg/kg BW/day) was given orally to rats as a reference drug concomitantly with oral supplementation of AlCl₃ (17 mg/kg body weight) for 28 days. Group 5 rats were orally treated with choline (1.1 g/kg) concomitantly with oral supplementation of AlCl₃ (17 mg/kg body weight). Group 6 was given 500 mg/kg of jambolan fruit ethanolic extract and 1.1 g/kg of choline orally to test for additive effects concurrently with oral supplementation of AlCl₃ (17 mg/kg bw) for 28 days. Body weight gain, feed intake, feed efficiency ratio, and relative brain, liver, kidney, and spleen weight were calculated after the trial. Brain tissue assessment was analyzed for antioxidant/oxidant markers, biochemical analysis in blood serum, a phenolic compound in Jambolan fruits extracted by high-performance liquid chromatography (HPLC), and histopathology of the brain. The results showed that Jambolan fruit extract and choline chloride improved brain functions, histopathology, and antioxidant enzyme activity compared with the positive group. In conclusion, administering jambolan fruit extract and choline can lower the toxic impacts of aluminum chloride on the brain.

Fenugreek seed ethanolic extract inhibited formation of advanced glycation end products via scavenging reactive carbonyl intermediates

Senescence is a natural phenomenon of growing old. It accelerates under certain conditions like diabetes mellitus resulting in early decline of bodily functions, which can be avoided by many claimed functional foods. The present study aims to investigate the anti-aging ability of Fenugreek seeds (Trigonellafoenum-graecum); a common ingredient of Indo-Pak cuisines. Briefly, the Fenugreek seeds extract (FgSE) in concentrationsof0.1, 0.5 and 1 mg/ml inhibited the formation of Advanced Glycation End products (AGEs) and fructosamine adducts in Bovine serum albumin (BSA)/fructose model in vitro. The BSA conformational analysis via Circular Dichorism and Congo red assays showed that it preserves secondary structure of BSA in aforementioned model. Although mechanistic studies revealed insignificant lysine blocking ability of Fenugreek by OPA assay, however carbonyl entrapping was found to be 24%, 34% and 42% at 0.1, 0.5 and 1 mg/ml, respectively. In vivo model of High Fructose diet (HFD) induced glycation, FgSE treatment in doses of 10, 25 & 50 mg/kg markedly improved Escape latency (p < 0.01) and preserved cognition in Morris Water Maze. Our data further exhibits significant decrease of CML (Nε-carboxymethyl lysine) levels in serum and hippocampus byFgSE treatment in comparison with HFD group. Therefore, we deduced that FgSE prevents glycation-induced memory decline via entrapping the reactive carbonyl intermediates, formed during production of AGEs. Hence, as a promising functional food it slows down the harmful process of glycation and aging associated morbidities.

Role of aluminum exposure on Alzheimer's disease and related glycogen synthase kinase pathway

Aluminum (Al) is an environmentally abundant metal that is not essential for life. There is considerable evidence that Al as a neurotoxic xenobiotic may play a role in the pathogenesis of neurodegenerative diseases like Alzheimer's disease (AD). Exposure to aluminum has been shown to cause neuronal damage that resembles the symptoms of AD. In this review, we will summarize recent data about Al as the possible risk of incidence of AD. Then glycogen synthase kinase-3 beta (GSK3β) contributes to the hyperphosphorylation of Tau protein, the main component of neurofibrillary tangles, one of the hallmarks of AD as one of the mechanisms behind Al neurotoxicity will be covered. Overall, there is still a need for epidemiological studies and more in vivo and in vitro studies to determine the exact mechanisms of its neurotoxicity and the role of GSK3β in both Al toxic effect and AD.

Comparative Study of Antioxidant, Antidiabetic, Cytotoxic Potentials, and Phytochemicals of Fenugreek (Trigonella foenum-graecum) and Ginger (Zingiber officinale)

Trigonella foenum-graecum and Zingiber officinale are used as traditional medicinal plants for the treatment of infectious and inflammatory diseases. However, a comparative analysis and bioactivities of T. foenum-graecum and Z. officinale lack some necessary information for therapeutic purposes. This study was designed to evaluate the biochemical characterizations and biological efficacy of T. foenum-graecum and Z. officinale as antioxidant, antidiabetic, antiamnesic, and cytotoxic agents. Antioxidant activity was determined by DPPH free radical scavenging assay. Antidiabetic potentials were evaluated by glycation, alpha-amylase, and acetylcholinesterase inhibition assays. We performed biochemical characterization through analyses of high-performance liquid chromatography (HPLC) and FTIR (Fourier transform infrared spectroscopy). Results revealed that total phenolic contents (TPCs) (g GAE/100 g) of T. foenum-graecum and Z. officinale were 5.74 ± 0.81 g and 6.15 ± 0.06 g, respectively, and total flavonoid contents (TFCs) varied from 1.51 ± 0.58 g CE/100 g to 17.54 ± 0.58. DPPH scavenging potentials of T. foenum-graecum and Z. officinale extract were 50.27% and 88.82%, respectively. Antiglycation potentials of T. foenum-graecum and Z. officinale showed a maximum activity at 16–29% and 96%. Alpha-amylase and alpha-glucosidase inhibition ranged from 9.43–24.95 and 10.52–27.89 and 54.97%, respectively. All the test samples of T. foenum-graecum and Z. officinale showed acetylcholinesterase inhibition potential at 0.37–46.88%. HPLC analysis of T. foenum-graecum revealed the presence of quercetin, gallic acid, caffeic acid, vanillic acid, syringic acid, and cumeric acid, while Z. officinale revealed the quercetin, gallic acid, vanillic acid, benzoic acid, chlorogenic acid, p.Coumaric acid, ferulic acid, and cinnamic acid. FTIR analysis revealed the presence of aldehydes, ketones, aromatic compounds, amines, and carbonyl groups in T. foenum-graecum, while alcohol, alkane, alkene, ketone, amine, and ether are bioactives present in the methanolic extract of Z. officinale. It was concluded that a comparative analysis of T. foenum-graecum and Z. officinale showed that Z. officinale showed higher therapeutic effects.

The Combination of Baicalein and Memantine Reduces Oxidative Stress and Protects against β-amyloid-Induced Alzheimer’s Disease in Rat Model

Alzheimer’s disease (AD) is a neuronal condition causing progressive loss of memory and cognitive dysfunction particularly in elders. An upsurge in the global old age population has led to a proportionate increase in the prevalence of AD. The current treatments for AD are symptomatic and have debilitating side effects. A literature review and current research have directed scientists to explore natural products with better safety and efficacy profiles as new treatment options for AD. Baicalein, belonging to the flavone subclass of flavonoids, has been reported for its anti-oxidant, anti-inflammatory, AChE enzyme inhibitory activity and anti-amyloid protein aggregation activity, which collectively demonstrates its benefits as a neuroprotective agent. Presently, memantine, a NMDAR antagonist, is one of the important drugs used for treatment of Alzheimer’s disease. The current study aims to investigate the effect of baicalein in combination with memantine in β-amyloid-induced AD in albino Wistar rats. Baicalein (10 mg/kg) alone, 5 mg/kg and 10 mg/kg in combination with memantine (20 mg/kg) was administered for 21 days. Treatment with baicalein in combination with memantine showed significant improvement in behavioural studies. The combination treatment decreased oxidative stress, β-amyloid plaque formation and increased the expression of brain-derived neurotrophic factor (BDNF) in the brain. From the results, it can be concluded that treatment with baicalein and memantine could be beneficial for reducing the progression of neurodegeneration in rats. Baicalein has an additive effect in combination with memantine, making it a potential option for the treatment of AD.

Leflunomide abrogates neuroinflammatory changes in a rat model of Alzheimer's disease: the role of TNF-α/NF-κB/IL-1β axis inhibition

Alzheimer's disease (AD) is one of the most common neurodegenerative diseases and is associated with disrupted cognition and behavior. Neuroinflammatory pathogenesis is the main component that contributes to AD initiation and progression through microglial activation and neuronal damage. Thus, targeting inflammatory pathways may help manage AD. In this study, for the first time, the potential prophylactic and therapeutic effects of leflunomide were investigated either alone or in combination with rivastigmine in aluminum chloride (AlCl₃)-induced AD-like rats using behavioral, biochemical, and histological approaches. Thirty-six adult male albino rats were divided into two protocols: the treatment protocol, subdivided into five groups (n = 6)-(1) control group, (2) AlCl₃ (50, 70, 100 mg/kg/I.P) group, (3) reference group (rivastigmine 2 mg/kg/P.O.), (4) experimental group (leflunomide 10 mg/kg/P.O.), and (5) combination group (rivastigmine + leflunomide); and the prophylactic protocol (leflunomide 10 mg/kg/P.O.), which started 2 weeks before AlCl₃ induction. The results showed that AlCl₃ disrupted learning and memory parameters in rats and increased amyloid-β plaque deposition and neurofibrillary tangle aggregation. Moreover, AlCl₃ administration markedly elevated acetylcholinesterase activity, nuclear factor-kappa β, tumor necrosis factor-α, and interleukin-1 beta, and marked degenerative changes in the pyramidal neurons. However, administration of leflunomide alone or with rivastigmine in AlCl₃-induced AD rats restored most of the behavioral, biochemical, and histological parameters triggered by AlCl₃ in rats. Our findings suggest that leflunomide can potentially restore most of the neuronal damage in the hippocampal tissues of AlCl₃-induced AD rats. However, these preclinical findings still need to be confirmed in clinical trials.

Effects of baicalein with memantine on aluminium chloride-induced neurotoxicity in Wistar rats

Alzheimer's disease is a progressive neurodegenerative condition. It is one of the most common 28 forms of dementia accounting for 60-80% of people suffering from dementia. There are very few medications that are approved for the treatment of Alzheimer's disease. Baicalein, belonging to the flavone subclass of flavonoids, has been reported to have a neuroprotective effect by reducing oxidative stress and neuroinflammation, inhibiting the AChE enzyme, and reducing amyloid protein aggregation and toxicity. Memantine is one of the most important drugs used for treating Alzheimer's disease. The purpose of this work was to study the effect of baicalein with memantine on aluminum chloride-induced neurotoxicity in Wistar rats. Aluminum chloride (100 mg/kg p.o.) was administered for 42 days in male Wistar rats to induce neurotoxicity. Baicalein alone (10 mg/kg) and a combination of baicalein (5 mg/kg and 10 mg/kg) with memantine (20 mg/kg) were administered for 42 days. Treatment of baicalein with memantine showed significant improvement in behavioral parameters. The combination reduced oxidative stress and the formation of β-Amyloid plaques and increased brain-derived neurotrophic factor (BDNF) expression. Based on findings, it can be concluded that treatment with baicalein and memantine may slow the progression of neurodegeneration in rats.

Quercetin Nanoemulsion Ameliorates Neuronal Dysfunction in Experimental Alzheimer's Disease Model

Aluminum is the most abundant metal that can get admission to the human through several means that include our food, drinking water, cans, drugs, and deodorants, causing neurodegenerative diseases such as Alzheimer's disease (AD). The present study aims to evaluate the role of quercetin nanoemulsion (QCNE) in attenuating neuronal dysfunction in aluminum chloride (AlCl3)-induced experimental AD. All animals were classified into six groups including negative control group (I): received a vehicle; QC group: received intraperitoneal (IP) injection of QC; Alzheimer's group: received AlCl3 orally; treated group (I): received AlCl3 orally and IP injection of QC; treated group (II): received AlCl3 orally and QC orally; and treated group (III): received AlCl3 orally and IP injection of QCNE. At the end of the experimental period (30 days), the brain was used to study biochemical parameters (measurement of neurotransmitters (serotonin, dopamine, and norepinephrine), oxidant/antioxidant parameters (reduced glutathione, malondialdehyde, superoxide dismutase, and advanced oxidation protein product), and inflammatory markers (adiponectin, interleukin 1β, and plasma tumor necrosis factor-alpha)), while another part was for brain immune-histochemical analysis (study cyclooxygenases (COX-1 and COX-2)). Results showed that the mean value of oxidative stress markers was significantly increased in the AD group as well as the inflammatory biomarkers and all the study neurotransmitters, whereas these parameters were attenuated in treated groups, especially those that received QCNE. The immunohistochemistry findings confirm our results. Both approaches (QC and QCNE) succeeded in retracting the negative impact of AlCl3. Meanwhile, the effect of QCNE is more potent in mitigating the impact mediated by AlCl3 in treated animals. In conclusion, the treatment mainly by QCNE has huge potential in protecting against AlCl3-induced neuronal dysfunction, as shown in our results by the elevation of brain antioxidant/anti-inflammatory activities and neurotransmitter levels as well as mending of the histopathological changes in animal models.

Assessment of the neuroprotective potential of d-cycloserine and l-serine in aluminum chloride-induced experimental models of Alzheimer’s disease: In vivo and in vitro studies

Alzheimer’s disease (AD) is a neurodegenerative disease characterized by the accumulation of amyloid-β (Aβ) plaques and neurofibrillary tangles in the brain accompanied by synaptic dysfunction and neurodegeneration. No effective treatment has been found to slow the progression of the disease. Therapeutic studies using experimental animal models have therefore become very important. Therefore, this study aimed to investigate the possible neuroprotective effect of D-cycloserine and L-serine against aluminum chloride (AlCl₃)-induced AD in rats. Administration of AlCl₃ for 28 days caused oxidative stress and neurodegeneration compared to the control group. In addition, we found that aluminum decreases α-secretase activity while increasing β-secretase and γ-secretase activities by molecular genetic analysis. D-cycloserine and L-serine application resulted in an improvement in neurodegeneration and oxidative damage caused by aluminum toxicity. It is believed that the results of this study will contribute to the synthesis of new compounds with improved potential against AlCl₃-induced neurodegeneration, cognitive impairment, and drug development research.

Exposure of aluminium to C6 glioma cells modulates molecular and functional neurotoxic markers

The risk of aluminium exposure to humans is very high as it may get into the human body through excessive dietary contaminants, inhalation of fine particulate matter, or through parenteral routes as a vaccine adjuvant and so forth. The increased level of aluminium in brain tissue has been shown to be associated with several neurodegenerative and neurotoxic adverse effects, including AD. However, the exact mechanism of aluminium-induced neurotoxicity is still unclear. Therefore, our study aimed to investigate the mechanism of neurotoxic and neurodegenerative effects through in vitro exposure of aluminium in rat glioma C6 cell line. The findings of our study have indicated that aluminium chloride exposure may lead to alteration in acetylcholine levels, increased oxidative imbalance and induction of molecular structural and functional markers of neuronal inflammation. This study also demonstrated that aluminium exposure may lead to the induction of caspase-3 along with apoptotic cell death and a significant increase in amyloid-beta and hyperphosphorylated tau levels in C6 cells. Thus, this study may provide a mechanistic understanding of the regulation of neuroinflammatory and neurodegenerative biomarkers due to aluminium exposure.

Intranasal Oxytocin Attenuates Cognitive Impairment, β-Amyloid Burden and Tau Deposition in Female Rats with Alzheimer's Disease: Interplay of ERK1/2/GSK3β/Caspase-3

Oxytocin is a neuropeptide hormone that plays an important role in social bonding and behavior. Recent studies indicate that oxytocin could be involved in the regulation of neurological disorders. However, its role in modulating cognition in Alzheimer’s disease (AD) has never been explored. Hence, the present study aims to investigate the potential of chronic intranasal oxytocin in halting memory impairment & AD pathology in aluminum chloride-induced AD in female rats. Morris water maze was used to assess cognitive dysfunction in two-time points throughout the treatment period. In addition, neuroprotective effects of oxytocin were examined by assessing hippocampal acetylcholinesterase activity, β-amyloid 1–42 protein, and Tau levels. In addition, ERK1/2, GSK3β, and caspase-3 levels were assessed as chief neurobiochemical mediators in AD. Hippocampi histopathological changes were also evaluated. These findings were compared to the standard drug galantamine alone and combined with oxytocin. Results showed that oxytocin restored cognitive functions and improved animals’ behavior in the Morris test. This was accompanied by a significant decline in acetylcholinesterase activity, 1–42 β-amyloid and Tau proteins levels. Hippocampal ERK1/2 and GSK3β were also reduced, exceeding galantamine effects, thus attenuating AD pathological hallmarks formation. Determination of caspase-3 revealed low cytoplasmic positivity, indicating the ceasing of neuronal death. Histopathological examination confirmed these findings, showing restored hippocampal cells structure. Combined galantamine and oxytocin treatment showed even better biochemical and histopathological profiles. It can be thus concluded that oxytocin possesses promising neuroprotective potential in AD mediated via restoring cognition and suppressing β-amyloid, Tau accumulation, and neuronal death.

Chronic oral exposure of aluminum chloride in rat modulates molecular and functional neurotoxic markers relevant to Alzheimer's disease

Aluminum is an environmentally abundant potential neurotoxic agent that may result in oxidative damage to a range of cellular biomarkers. The potential sources of aluminum accumulation in body include drinking water, food, medicines, vaccines, and aluminum cookware utensils etc. The accumulation of aluminum in brain is reported to be associated with cholinergic dysfunction, oxidative stress and neuronal damage, that may ultimately cause Alzheimer's disease. Since chronic exposure of aluminum leads to its accumulation in brain, so this study was done by a long-term (24 weeks) low dose (20 mg/kg) oral exposure of aluminum chloride in rats. In this chronic model, we have evaluated the major hallmarks of Alzheimer's disease including amyloid beta (Aβ_1-42) and phosphorylated-tau (p231-tau) protein in brain tissue. Furthermore, we evaluated the level of acetyl cholinesterase activity, inflammatory cytokines such as TNF-α, IL-6 and IL-1β, and oxidative stress biomarkers in rat brain in this model. The neurobehavioral parameters were also assessed in animals by using spontaneous locomotor activity, passive avoidance, rotarod test and novel object recognition test to evaluate alteration in learning, memory and muscle co-ordination. We found that chronic oral exposure of aluminum chloride causes a significant increase in structural hallmarks such as Aβ_1-42 and p231-tau levels along with proinflammatory cytokines (TNF-α and IL-6), oxidative stress, and a decrease in antioxidant markers such as GSH and catalase. in the brain tissue. These biomarkers significantly affected neurobehavioral parameters in animals. This study provides a mechanistic understanding of chronic aluminum-induced neuronal toxicity in brain with relevance to Alzheimer's disease.

Modified Low-Temperature Extraction Method for Isolation of Bletilla striata Polysaccharide as Antioxidant for the Prevention of Alzheimer's Disease

Amyloid-β (Aβ) peptides play a key role in Alzheimer's disease (AD), the most common type of dementia. In this study, a polysaccharide from Bletilla striata (BSP), with strong antioxidant and anti-inflammatory properties, was extracted using a low-temperature method and tested for its efficacy against AD, in vitro using N2a and BV-2 cells, and in vivo using an AD rat model. The characterization of the extracted BSP for its molecular structure and functional groups demonstrated the effectiveness of the modified method for retaining its bioactivity. In vitro, BSP reduced by 20% reactive oxygen species (ROS) levels in N2a cells (p = 0.0082) and the expression levels of inflammation-related genes by 3-fold TNF-α (p = 0.0048), 4-fold IL-6 (p = 0.0019), and 2.5-fold IL-10 (p = 0.0212) in BV-2 cells treated with Aβ fibrils. In vivo, BSP recovered learning memory, ameliorated morphological damage in the hippocampus and cortex, and reduced the expression of the β-secretase protein in AlCl3-induced AD rats. Collectively, these findings demonstrated the efficacy of BSP for preventing and alleviating the effects of AD.

Neuroprotective effect of Bryophyllum pinnatum flavonoids against aluminum chloride-induced neurotoxicity in rats

Toxic metals such as aluminum accumulation in the brain have been associated with the pathophysiology of several neurodegenerative disorders. Bryophyllum pinnatum leaves contain a vast array of polyphenols, particularly flavonoids, that may play a role in the prevention of toxic and degenerative effects in the brain. This study assessed the neuro-restorative potential of leaves of B. pinnatum enriched flavonoid fraction (BPFRF) in aluminum-induced neurotoxicity in rats. Neurotoxicity was induced in male Wistar rats by oral administration of 150 mg/kg body weight of aluminum chloride (AlCl₃) for 21 days. Rats were grouped into five (n = 6); Control (untreated), Rivastigmine group, AlCl₃ group and BPFRF group (50 and 100 mg/kg b.wt.) for 21 days. Neuronal changes in the hippocampus and cortex were biochemically and histologically evaluated. Expression patterns of acetylcholinesterase (AChE) mRNA were assessed using semi-quantitative reverse-transcription-polymerase chain reaction protocols. Molecular interactions of BPFRF compounds were investigated in silico. The results revealed that oral administration of BPFRF ameliorated oxidative imbalance by augmenting antioxidant systems and decreasing lipid peroxidation caused by AlCl₃. BPFRF administration also contributed to the down-regulation of AChE mRNA transcripts and improved histological features in the hippocampus and cortex. Molecular docking studies revealed strong molecular interactions between BPFRF compounds, catalase, superoxide dismutase and glutathione peroxidase Overall, these findings suggest the neuroprotective effect of Bryophyllum pinnatum against aluminum-induced neurotoxicity.

Chitosan and solid lipid nanoparticles enhance the efficiency of alpha-lipoic acid against experimental neurotoxicity

Alpha-lipoic acid (α-LA) is characterized by its unpleasant odor, poor bioavailability and stability. Nanotechnology was applied to overcome this limitation. So we aimed in this study to formulate α-LA in two different forms of chitosan nanoparticles (CsNPs) and solid lipid nanoparticles (SLNPs) and characterize them in terms of physical properties and biological activities against aluminum chloride (AlCl₃)-induced neurotoxicity in rats. The vivo study was processed on 50 rats divided into 5 groups as follow: control, neurotoxic, treated α-LA, treated α-lipoic acid-loaded chitosan nanoparticles (α-LA-CsNPs) and treated α-lipoic acid-loaded solid lipid nanoparticles (α-LA-SLNPs) groups. The result was depicted by transmission electron microscopy (TEM) revealed that α-LA-SLNPs had a regular spherical shape while α-LA-CsNPs showed an irregular spherical form. Dynamic light scattering (DLS) analysis showed that the average particle size for α-LA-SLNPs was about 71 nm and for α-LA-CsNPs was about 126 nm. After the experimental period, we observed that AlCl₃ administration significantly increased oxidative stress, neuroinflammation and apoptosis and decreased brain fatty acid contentsand brain-derived neurotrophic factor,while α-LA, α-LA-CsNPs and α-LA-SLNPs were able to ameliorate these negative changes in the neurotoxic rats. However, the effect of the α-LA-loaded NPs was more prominent than that of pristine α-LA but the α-LA-SLNPs group was almost close to the control group. Conclusion: α-LA can attenuate neurotoxicity induced by AlCl3, attributed to its anti-inflammatory, antioxidant and anti-apoptotic activities in addition to the effectiveness of the encapsulation technique that can increase the efficiency and stability of α-LA. Moreover, α-LA-SLNPs are more efficient than α-LA-CsNPs.

Delineation of Neuroprotective Effects and Possible Benefits of AntioxidantsTherapy for the Treatment of Alzheimer's Diseases by Targeting Mitochondrial-Derived Reactive Oxygen Species: Bench to Bedside

Alzheimer's disease (AD) is considered the sixth leading cause of death in elderly patients and is characterized by progressive neuronal degeneration and impairment in memory, language, etc. AD is characterized by the deposition of senile plaque, accumulation of fibrils, and neurofibrillary tangles (NFTs) which are responsible for neuronal degeneration. Amyloid-β (Aβ) plays a key role in the process of neuronal degeneration in the case of AD. It has been reported that Aβ is responsible for the production of reactive oxygen species (ROS), depletion of endogenous antioxidants, increase in intracellular Ca²⁺ which further increases mitochondria dysfunctions, oxidative stress, release of pro-apoptotic factors, neuronal apoptosis, etc. Thus, oxidative stress plays a key role in the pathogenesis of AD. Antioxidants are compounds that have the ability to counteract the oxidative damage conferred by ROS. Therefore, the antioxidant therapy may provide benefits and halt the progress of AD to advance stages by counteracting neuronal degeneration. However, despite the beneficial effects imposed by the antioxidants, the findings from the clinical studies suggested inconsistent results which might be due to poor study design, selection of the wrong antioxidant, inability of the molecule to cross the blood-brain barrier (BBB), treatment in the advanced state of disease, etc. The present review insights into the neuroprotective effects and limitations of the antioxidant therapy for the treatment of AD by targeting mitochondrial-derived ROS. This particular article will certainly help the researchers to search new avenues for the treatment of AD by utilizing mitochondrial-derived ROS-targeted antioxidant therapies.

Cardioprotective effects of Fenugreek (Trigonella foenum-graceum) seed extract in streptozotocin induced diabetic rats

Introduction: Inadequate control of diabetes mellitus (DM) leads to considerable cardiovascular implications like diabetic cardiomyopathy (DCM). Cardiomyocyte apoptosis is one of the main mechanisms of DCM pathogenesis associated with hyperglycemia, oxidative stress, inflammation, hyperlipidemia and several other factors. Trigonella foenum-graecum (Fenugreek) has been long used as a traditional medicine and has many therapeutic effects, including anti-diabetic, anti-hyperlipidemia, anti-inflammatory and anti-oxidant properties. The current study aimed to investigate cardioprotective effects of fenugreek seed on diabetic rats. Methods: Diabetes was induced in forty-two male rats by injection of streptozotocin (STZ) (60 mg/ kg). Diabetic animals were treated with three different doses of fenugreek seed extract (50, 100 and 200 mg/kg) or metformin (300 mg/kg) for six weeks by gavage. Nondiabetic rats served as controls. Glucose, cholesterol, and triglycerides levels were measured in the blood samples, and oxidative stress markers as well as gene expression of ICAM1 , Bax and Bcl2 were assessed in the cardiac tissues of the experimental groups. Results: Diabetic rats exhibited increased serum glucose, cholesterol and triglycerides levels, elevated markers of oxidative stress thiobarbituric acid-reacting substances (TBARS) levels , total thiol groups (SH), catalase (CAT) and superoxide dismutase (SOD) activity, and enhanced apoptosis cell death (ratio of Bax/Bcl2). Fenugreek seed extract considerably improved metabolism abnormalities, attenuated oxidative stress and diminished apoptosis index. Conclusion: Our study suggests that fenugreek seed may protect the cardiac structure in STZ-induced diabetic rats by attenuating oxidative stress and apoptosis.

Effect of epigallocatechin gallate on aluminum chloride-induced changes in behavior, biochemical parameters, and spermatogenesis of Sprague-Dawley rats

Background

Epigallocatechin gallate (EGCG) acts as an antioxidant by preventing oxidative stress. The effect of EGCG on aluminum-induced testicular injury is not clear. Hence, the present study is planned to investigate the effect of EGCG on aluminum chloride (AlCl3)-induced changes in behavior, biochemical parameters, and spermatogenesis in male Sprague-Dawley rats. The rats were divided into six groups with six animals each. All the animals were administered with respective assigned treatment once daily for 28 days. The animals in groups I to VI were administered with drug vehicle, AlCl3, vitamin C, EGCG, vitamin C, and EGCG, respectively. The animals in groups V and VI were additionally challenged with AlCl3 (10 mg/kg) immediately after vitamin C and EGCG administration, respectively. Changes in behavior were measured on day 1, 14 and 28. At the end of the study, the blood sample was collected from all the animals, and the serum was separated and used for biochemical analysis. Later, the rats were subjected to bilateral orchiectomy; sperm was collected from the cauda epididymis for microscopic examination. Then, the animals were sacrificed, and the organs such as the brain, lungs, heart, liver, kidney, spleen, and testis were collected for organ weight analysis.

Results

The animal administered with AlCl3 showed a reduction in locomotor activity, grip strength, and escape latency time whereas vitamin C prevented the effect of AlCl3. But, EGCG did not show any significant changes in AlCl3-induced behavioral and biochemical changes. At the end of the study, vitamin C prevented AlCl3-induced behavioral and biochemical changes. The group of animals administered with AlCl3 showed a reduction in the number of spermatozoa whereas AlCl3 + vitamin C and AlCl3 + EGCG did not show any significant changes in the number of spermatozoa when compared to the control group.

Conclusion

EGCG prevented AlCl3-induced reduction in epididymal sperm count of male rats and did not show any significant effect on AlCl3-induced changes in behavior and biochemical parameters, whereas vitamin C had an ameliorative effect on AlCl3-induced changes in behavior, biochemical parameter, and spermatogenesis.

Graphical abstract

Neuroprotective Effects of Higenamine Against the Alzheimer's Disease Via Amelioration of Cognitive Impairment, A Burden, Apoptosis and Regulation of Akt/GSK3β Signaling Pathway

The present investigation was envisaged to elucidate the neuroprotective effect of Higenamine (HGN) against aluminum chloride (AlCl₃) triggered experimental Alzheimer's disease (AD) rat model. Thirty-six male albino Wister rats were randomized and divided in 6 groups and subjected to experimentation for 6 weeks. Control group, AlCl₃ (100 mg/kg orally), HGN (50 mg/kg orally), HGN25, HGN50, HGN75 (HGN 25, 50 and 75 mg/kg respectively and AlCl₃ 100 mg/kg orally). After completion of 42 days protocol, the animals were subjected to passive avoidance test. The animals were then anesthetized by intramuscularly injecting ketamine hydrochloride (24 mg/kg body weight) and euthanized by cervical amputation. Cortical and hippocampal tissues were carefully removed and were employed for quantification of aluminum and acetylcholinesterase. The tissues were quantified using Western blotting and detection kits for APP, Aβ_1-42, β and γ secretases, Bax, Bad, caspases-9, cyto-c, pAkt and pGSK-3β, and oxidative markers. HGN significantly protected AlCl₃ induced memory and learning impairments, Al overload, AChE hyperactivity, amyloid β (Aβ) burden and apoptosis in brain tissues via activating Akt/GSK3β pathway. HGN attenuated oxidative damage induced by Al by modulation of oxidative markers. Our findings advocate the neuroprotective effect of HGN in AlCl₃ induced AD rat model.

HPLC-PDA-MS/MS profiling of secondary metabolites from Opuntia ficus-indica cladode, peel and fruit pulp extracts and their antioxidant, neuroprotective effect in rats with aluminum chloride induced neurotoxicity

Opuntia ficus-indica (L.) Mill. (OFI), also known as Indian fig Opuntia or prickly pear, is a member of the family Cactaceae that produces edible, nutritionally rich sweet fruits. It has been traditionally used to treat several health disorders and is considered to possess various therapeutic properties. In this work, we have characterized 37 secondary metabolites using HPLC-MS/MS, identified the polysaccharide from the fruits and cladodes pulp, and estimated the neuroprotective activity. All tested extracts exhibited substantial antioxidant activities in-vitro and neuroprotective potential in AlCl₃ induced Alzheimer's condition. Administration of OFI extracts attenuated AlCl₃ induced learning and memory impairment as confirmed from passive avoidance test and counteracted the oxidative stress as manifested from decreasein the elevated MDA level, increased TAC, GSH, SOD and CAT levels. OFI extracts significantly decreased the elevated brain levels of proinflammatory cytokines (NF-κβ and TNF-α), increased anti-inflammatory cytokine (IL-10), and monoamine neurotransmitters (NE, DA, 5-HT) as compared to positive control group. The extracts showed a significant decrease in acetylcholinesterase level (AChE) as compared with AlCl_3. Furthermore, molecular docking was performed to investigate the ability of the major constituents of OFI extracts to interact with acetylcholinesterase (AChE) and serotonin transporter (SERT). Among the tested extracts, cladodes contain highest phenolic content and exhibited the highest antioxidant, anti-inflammatory and neuroprotective activities, which could be attributed to presence of several polyphenols, which could function as AChE and SERT inhibitors. Opuntia ficus-indica might be promising candidate for treating Alzheimer disease, which makes it a subject for more detailed studies.

Histomorphological evaluations on the frontal cortex extrapyramidal cell layer following administration of N-Acetyl cysteine in aluminum induced neurodegeneration rat model

Aluminum is a potent neurotoxin used in animal models of neurodegenerative diseases like Alzheimer's disease (AD), in which oxidative stress mediates tissue pathogenesis in vivo. N-acetyl cysteine (NAC) is a glutathione precursor with reported antioxidant and neuroprotective potentials. Recent therapy for combating AD is known to provide only symptomatic relief thus necessitating the discovery of new drugs and their mechanism of action. This study was aimed to demonstrate the in vivo neuroprotective effect of NAC against aluminum (Al3+)-induced neuro-degeneration in rats (a model for AD). Twenty- five (25) adult male Wistar rats used for this study were divided into 5 groups: Group A = Control, B = Aluminum chloride (200 mg/kg), C = 1000 mg/kg of NAC + Aluminum chloride (200 mg/kg), D = 1000 mg/kg of NAC, E = Aluminum chloride (200 mg/kg) was orally administered daily for 3 weeks and discontinued for one week. Frontal Cortex harvested for histological analysis using Haematoxylin and Eosin stain, Cresyl Fast Violet stain for Nissl granules and Glial fibrillary acidic protein immunohistochemistry specific for astrocytes. Aluminum significantly induced oxidative stress, coupled with marked neurons necrosis, chromatolysis and gliosis in the frontal cortex, upon NAC administration, there was neuro anti-inflammatory response as seen in the significant reduction in astrocytes expression, neuronal cell death and Nissl body aggregation which attenuates neuropathological deficits induced by Al3+. It was shown that aluminum is a neurotoxin mediating AD-like oxidative stress, NAC has a therapeutic potential associated with its potent in vivo interaction with astrocytes in response to Al3+ neuro-inflammation seen in positive expression of Nissl granules and glial cells in addition to possibility of endogenous glutathione neuroprotection after withdrawal of stress mediator in neurodegeneration. Graphical abstract.

Clopidogrel combats neuroinflammation and enhances learning behavior and memory in a rat model of Alzheimer's disease

BACKGROUND AND AIM

Alzheimer's disease (AD) is a progressive neurodegenerative disease. Multiple molecular mechanisms have been employed in its pathogenesis such as Amyloid β (Aβ) formation, tau protein hyperphosphorylation, reduced acetylcholine (ACh) level, and neuroinflammation. This study aimed to assess the possible neuroprotective effect of clopidogrel in AD model induced by aluminum chloride (AlCl₃) in rats.

METHODS

Sixty adult male Sprague-Dawley rats were divided into four different groups: Control, AlCl₃, AlCl₃ + donepezil, and AlCl₃ + Clopidogrel. AlCl₃ and the drugs were given orally once/day for 42 days. The spatial learning and memory and recognition memory were evaluated using Morris Water Maze (MWM) and Novel Object Recognition (NOR) tests, respectively. After euthanasia, hippocampal acetylcholinesterase (AChE) activity, tumor necrosis factor-alpha (TNF-α), and interleukin-1β (IL-1β) levels were biochemically assessed. Moreover, amyloid precursor protein (APP) mRNA gene expression was analyzed in the hippocampi of all rats. Histopathology for amyloid plaques was done.

RESULTS

Clopidogrel co-treatment significantly ameliorated the cognitive deficits induced by AlCl₃ in rats. Besides, clopidogrel significantly reduced AChE activity, TNF-α and IL-1β concentrations, and APP mRNA gene expression in the hippocampi of rats compared to AlCl₃ rats. The decrease of hippocampal TNF-α and IL-1β concentrations by clopidogrel was significant compared to donepezil co-treated rats. Clopidogrel co-treatment lessened amyloid plaque deposition in the hippocampal tissues of rats compared to AlCl₃ rats.

CONCLUSION

These findings demonstrate that clopidogrel could alleviate learning and memory deficit induced by AlCl₃ in rats and significantly reduced AChE activity. The neuroprotective outcome of clopidogrel might be assigned to its anti-inflammatory effect.

Amelioration of Aluminium Chloride (AlCl3) Induced Neurotoxicity by Combination of Rivastigmine and Memantine with Artesunate in Albino Wistar Rats

Alzheimer’s disease (AD) is an age-related progressive disorder characterized by neurodegeneration and accumulation of abnormal proteins. Artesunate, an anti-malarial drug has recently been shown to have anti-inflammatory, antiviral, angiogenic and other pleiotropic effects. It has also improved cognitive decline induced by hepatic coma which is suggestive of its role in learning and memory. In view of this, the current study was planned to assess the effect of the combination of artesunate with rivastigmine and memantine in aluminium chloride induced neurotoxicity. The study was conducted on 24 male adult albino wistar rats which were divided into four groups (n=6). Group - I to IV received saline, aluminium chloride (AlCl3), AlCl3 + artesunate +rivastigmine, AlCl3 + artesunate + memantine for 60 days respectively. After the 60th day of treatment, all animals were subjected to a passive avoidance task. All the animals were then sacrificed to study the histopathological changes in the hippocampus. Artesunate in combination with rivastigmine and memantine showed significant improvement in memory impairment and reduced neuronal death. Neuronal viability was more prominent in combination treatments as shown by histopathological results. Artesunate in combination with rivastigmine and memantine could be useful in AD. Artesunate can be used as an adjuvant therapy because artesunate combined with standard drugs produced significant neuroprotective effect.

Experimental and Computational Studies to Characterize and Evaluate the Therapeutic Effect of Albizia lebbeck (L.) Seeds in Alzheimer's Disease

Background and Objectives: Alzheimer's disease (AD) is a neurodegenerative disorder that deteriorates daily life due to loss of memory and cognitive impairment. It is believed that oxidative stress and cholinergic deficit are the leading causes of AD. Disease-modifying therapies for the treatment of AD are a challenging task for this century. The search for natural and synthetic agents has attracted the attention of researchers. The objective of this study was a scientific approach to search for most suitable remedy for AD by exploiting the potential of Albizia lebbeck (L.) seeds. Materials and Methods: Hydromethanolic extract of Albizia lebbeck seeds (ALE) was prepared by maceration. The plant was characterized by physico-chemical, phyto-chemical, and high-performance liquid chromatography (HPLC). Thirty-six Wistar albino rats were used in this study and divided into six groups (n = 6). Group I: normal control; Group II: disease control (AlCl3; 100 mg/Kg); Group III: standard control (galantamine; 0.5mg/Kg); Groups IV-VI were treated ALE at 100, 200 and 300 mg/Kg dose levels, respectively. All the treatments were given orally for 21 consecutive days. Y-maze, T-maze, Morris water maze, hole board, and open field behavioral tests were performed to analyze the cognitive impairment. Biochemical, histological, and computational studies were performed to support the results of behavioral tests. Results: HPLC analysis indicated the presence of quercetin, gallic acid, m-coumaric acid, and sinapic acid. ALE significantly improved the memory and cognitive impairments. Endogenous antioxidant stress biomarker levels and histopathological outcomes supported the therapeutic potential of A. lebbeck in AD. Cholinergic deficits were also ameliorated by ALE co-administration, possibly by the inhibition of hyperactive acetylcholinesterase (AChE). Docking studies supported the potential of ALE against AD. Conclusions: The data suggested that ALE has neuroprotective potential that can be exploited for beneficial effects to treat AD.

Amebicidal effects of fenugreek (Trigonella foenum-graecum) against Acanthamoeba cysts

Trigonella foenum-graecum L. (TF) is known to the public as a chest emollient, mucous expectorant, laxative and is used to prevent maturation of boils and diabetes since ancient times. In this study, we aimed to determine the amebicidal effects against Acanthamoeba cysts. Plant extracts were prepared at concentrations of 1, 2, 4, 8, 16, and 32 mg/ml and were placed in a hemocytometer with cell counts 22 × 106 cell/ml. The fatty acid profiles of TF seeds were determined. Standard Acanthamoeba cysts were added and incubated at 25°C. The viability of the parasite was checked and recorded at hours 3, 24, 48, 72, 96, and 102. The values of lethal concentration doses (LD50 and LD90) were calculated using probit analysis. This study revealed that T. foenum-graecum prevented proliferation of the parasite at certain times. However, further for in vivo and controlled experimental studies are needed in order to find out how to use this plant as medication.

Asiatic Acid Attenuated Aluminum Chloride-Induced Tau Pathology, Oxidative Stress and Apoptosis Via AKT/GSK-3β Signaling Pathway in Wistar Rats

Asiatic acid (AA), a triterpenoid present in Centella asiatica, possesses the ability to cross blood brain barrier and received considerable attention for its neuroprotective role. We have reported the benefit of AA against aluminum chloride (AlCl₃)-induced amyloid pathology, enhanced acetylcholine esterase (AChE) activity, and inflammation in Alzheimer's disease (AD) like model rats. Based on that, to find the exact mechanism of action of AA, the present study was designed to evaluate the oxidative stress, tau pathology, apoptosis, and Akt/GSK3β signaling pathway on AlCl₃-induced neurotoxicity in Wistar rats. AD-like pathology was induced by oral administration of AlCl₃ (100 mg/kg b.w.) for 6 weeks, which demonstrated a significant reduction in spatial memory performance, anxiety, and motor dysfunction and diminished the expression of cyclin-dependent kinase 5 (CDK 5-enzyme implicated in the phosphorylation of tau proteins), pTau, oxidative stress, and apoptosis, whereas oral ingestion of AA (75 mg/kg b.w.) for 7 weeks attenuated the above-said indices, which could be by activating Akt/GSK3β pathway. Current results suggested that AA could be able to modulate various pathological features of AD and could hold promise in AD treatment.

Multiple pharmacological activities of Caesalpinia crista against aluminium-induced neurodegeneration in rats: Relevance for Alzheimer's disease

Alzheimer's disease (AD) is the most common form of dementia and mainly affects cognitive function of the aged populations. Aluminium, a neurotoxic metal, has been suggested as a contributing factor of AD. Caesalpinia crista is a medicinal plant known for its anti-microbial, anti-inflammatory and anti-oxidant properties. The present study was conducted in order to evaluate the neuroprotective effects of methanolic extracts of C. crista (MECC) on aluminium-induced neurodegeneration in rats. Co-administration with MECC significantly and dose dependently ameliorated the aluminium-dependent cognitive impairment, AChE hyperactivity and oxidative stress in the hippocampus and in the frontal cortex of rat brain. Moreover, MECC reduced the neuronal injury induced by aluminium as shown by the diminution of neuron loss and pyknosis in the CA1 and CA3 regions of the hippocampus. From this study, it is inferred that MECC protect against aluminium-induced behavioral alterations, cognitive function, oxidative stress and neuroinflammation in vivo. Therefore, this plant may serve as a source of natural products having multiple functions and could be utilized as an anti-AD preparation.

Protective effects of thymoquinone on D-galactose and aluminum chloride induced neurotoxicity in rats: biochemical, histological and behavioral changes

OBJECTIVES

Thymoquinone (TQ), the main active ingredient in Nigella sativa oil, exhibits various bioactivities. This study aimed to investigate the effect of TQ on neurobehavioral and neuropathological alterations induced by aluminum trichloride (AlCl₃) and D-galactose (D-gal)-in male rats and to explore the related mechanisms.

METHODS

D-gal (60 mg/kg day) and AlCl₃ (10 mg/kg day) were given intraperitoneally (i.p.) once daily for 42 days and after 4 weeks TQ was concomitantly administered intragastrically (i.g.) (20 mg/kg/day) once daily for 14 days. Then, memory function was evaluated by Morris water maze test (MWM). Superoxide dismutase (SOD), Total antioxidant capacity (TAC), Acetylcholinesterase (AChE) activities, and malondialdehyde (MDA), nitric oxide (NO), brain-derived neurotrophic factor (BDNF), and B-cell lymphoma-2 (Bcl-2) levels in whole brain were assessed with the biochemical technique. Tumor necrosis factor-alpha (TNF-α) and Acetylcholine (ACh) were also assessed using an immunohistochemical technique.

RESULTS

Administration of TQ significantly improved cognition. In addition, TQ significantly increased SOD and TAC and decreased AChE activities. It also decreased MDA and NO levels as well as TNF-α immunoreactivity and increased BDNF and Bcl-2 levels as well as ACh immunoreactivity.

DISCUSSION

Our results indicate that TQ prevents D-gal/AlCl₃-induced cognitive decline by enhancing cholinergic function and synaptic plasticity as well as attenuation of oxidative damage, neuronal apoptosis, and neuroinflammation. These results indicate that TQ holds potential for neuroprotection and may be a promising approach for the treatment of neurodegenerative disorders.

Hyperforin attenuates aluminum-induced Aβ production and Tau phosphorylation via regulating Akt/GSK-3β signaling pathway in PC12 cells

Aluminum (Al) is a neurotoxicant and cause β-amyloid (Aβ) peptides aggregation and tau hyperphosphorylation. Hyperforin (HF) is one of the major active constituents of the extracts of St. John's Wort (Hypericum perforatum), can treat Alzheimer's disease (AD) and other diseases involving peptide accumulation and cognition impairment. To determine the effects of HF on Al-induced Aβ formation and tau hyperphosphorylation, PC12 cells were cultured and treated with Al-malt (500μM) and/or HF (1μM). The results showed that HF treatment significantly attenuated Al-malt-induced Aβ_1-42 production by reducing the expressions of APP, BACE1 and PS1, while increasing the expressions of sAPPα, ADAM9/10/17, and tau phosphorylation in PC12 cells. In addition, HF treatment also increased phosphorylation of AKT (Ser473) and inhibited GSK-3β activity by increasing phosphorylation of GSK-3β (Ser9). These results indicated that HF may exert the protection via regulating the AKT/GSK-3β signaling to reduce Aβ production and tau phosphorylation in PC12 cells. Furthermore, these results could lead a possible therapeutics for the management of Al neurotoxicity.