A Long Journey into Aging, Brain Aging, and Alzheimer's Disease Following the Oxidative Stress Tracks

Ginseng in delaying brain aging: Progress and Perspectives

BACKGROUND

The Shennong Bencao Jing (Shennong's Classic of Materia Medica) records that Panax ginseng C. A. Mey (ginseng) 'lightens the body and prolongs life'. Many investigations have documented that ginseng exerts neuroprotective effects by mitigating the aging of the brain. However, a comprehensive review of the impacts of ginseng on brain aging remains lacking.

PURPOSE

This study aims to review the advances in ginseng research regarding its role in delaying brain aging, focusing on its bioactive constituents, underlying mechanisms and potential side effects. The findings provide scientific pieces of evidence to support the medical utilization of ginseng in the delaying senescence and the management of aging-related diseases.

METHODS

This review includes studies on ginseng and brain aging in humans, retrieved from English-language research articles published between 2017 and the present in the PubMed and Web of Science databases. The work focused on ginseng, brain aging, and aging-related diseases, utilizing keywords such as "Ginseng", "Brain aging", "central nervous system", "intracellular homeostasis", "peripheral system", etc. RESULTS: Ginseng comprises a varied spectrum of biologically bioactive constituents, such as ginsenosides, Maillard reaction products, ginseng polysaccharides, volatile oils, amino acids, proteins, etc. These components work to contribute to their significant medicinal value. Based on the traditional Chinese medicine (TCM) theory that "the heart and brain are interconnected, the liver and brain are mutually supportive, the brain and spleen are related, the brain and lung are linked, and the brain and kidney work in harmony," we summarize that ginseng may sustain neural homeostasis through both central and peripheral perspectives. Additionally, the potential toxic side effects of ginseng are minimal.

CONCLUSION

Ginseng and its bioactive constituents exhibit considerable promise in delaying brain aging and treating neurodegenerative diseases. Future research should prioritize exploring the direct targets of ginseng and its active ingredients, and work toward establishing precise drug-target-efficacy relationships. This approach will facilitate the translation of these findings into clinically viable therapeutic approaches.

Lactoferrin ameliorates cognitive impairment in D-galactose-induced aging mice by regulating the PI3K/Akt/mTOR signaling pathway and the microbiome-gut-brain axis

Lactoferrin (LF) has been shown to be effective in attenuating oxidative stress, neuroinflammation, but its potential and mechanisms in alleviating brain aging remain to be clarified. In this study, the effect of different doses of LF (L: 50, M: 500 and H: 2000 mg/kg) on D-galactose (D-gal)-induced brain aging C57BL/6 mice was evaluated. The results showed that body weight, mobility, and spatial memory capacity of aging mice were restored after LF (M & H) intervention. It also attenuated hippocampal neuronal damage and intestinal barrier damage in aging mice. LF (M & H) increased brain and serum levels of antioxidant defense enzymes (SOD, GSH, CAT) and decreased colon and serum levels of inflammatory factors (IL-1β, IL-6 and TNF-α). Western blotting results showed that LF (M & H) increased LC3II/I, Beclin1 expression, decreased p-mTOR, p-akt, and p62 expression, and restored autophagy through the PI3K/Akt/m-TOR pathway. Furthermore, LF (M & H) protected the intestinal barrier by regulating the ratio of Firmicutes/Bacteroidetes and increased levels of the beneficial metabolites short chain fatty acids (SCFAs). Notably, LF (H) exhibited the best anti-aging potential. 500 mg/kg/day LF intervention may be cost-effective in prevents brain aging by regulating the autophagy pathway and the microbiome-gut-brain axis.

Evaluation of the Effects of Thymoquinone on RAGE/NOX4 Expressions and Brain Tissue Morphometry in Experimental Alzheimer's Disease Induced by Amyloid Beta 1-42 Peptide

The onset of Alzheimer's disease (AD) is attributed to widespread amyloid beta (Aβ) plaque accumulation, tau hyperphosphorylation, oxidative stress, and neuroinflammation. However, the underlying mechanism of AD remains unclear, and no curative treatment currently exists. The aim was to investigate the effect of thymoquinone by suppressing the RAGE/NOX4 pathway in AD. Mice (n = 60) were divided into five groups, and an experimental AD model induced by an Aβ1-42 peptide was established in two groups. We also administered 5 mg/kg thymoquinone (TMQ) to the mice for its properties to slow or treat neurodegeneration in AD. Behavioral tests for memory and emotional states, micro-computed tomography (Micro CT) to assess brain volume, ELISA to measure malondialdehyde (MDA) levels, hematoxylin and eosin staining (H&E) to evaluate neuronal degeneration were used. Immunohistochemical (IHC), Western blot (WB), and real-time polymerase chain reaction (PCR) methods were used to evaluate the inhibitory effect of TMQ on a receptor for advanced glycation end products (RAGE)/nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 4 (NOX4) signaling in AD. The results showed that TMQ may have ameliorative effects on memory, spatial learning, learning ability, and anxiety in AD. We showed that TMQ has an antioxidative effect by decreasing MDA levels by the ELSIA method (p < 0.05). There was a marked increase in neuronal degeneration in AD mice compared to other groups (p < 0.05). We concluded that TMQ could ameliorate neuronal degeneration in AD by H&E staining and suppress RAGE/NOX4 signaling by IHC and WB analysis. We concluded that TMQ could be therapeutic in AD by reducing AB expression level by IHC analysis (p < 0.05). Real-time PCR analysis showed that APP (p < 0.05), RAGE, and NOX4 (p < 0.05) gene expressions could be reduced by TMQ. In conclusion, TMQ has a high therapeutic potential in AD and an effective preventive and therapeutic strategy can be developed with more comprehensive studies on TMQ.

Prevalence and correlation of sarcopenia with Alzheimer's disease: A systematic review and meta-analysis

BACKGROUND

Sarcopenia, which is defined by a decline in skeletal muscle mass and strength associated with aging, is common among older individuals and presents considerable health dangers. Alzheimer's disease (AD) is a prevalent degenerative brain condition linked to a decrease in cognitive function. The intersection of these conditions remains underexplored. The goal of this systematic review and meta-analysis was to establish the frequency of sarcopenia in individuals with AD and investigate the relationship between sarcopenia and AD.

METHODS

We performed an extensive review of literature databases, including PubMed, Embase, Web of Science, and the Cochrane Library, through April 2024. The inclusion criteria included studies that provided data on the frequency of sarcopenia in patients with AD or that examined the odds ratios (ORs) associated with these comorbidities. R Studio (4.3.1) was utilized for conducting the statistical analyses.

RESULTS

A total of 27 studies, comprising 3902 AD patients were included. In patients with AD, the combined occurrence of sarcopenia was 33.9%, with a confidence interval (CI) of 95%, ranging from 27.6% to 40.2%. Sarcopenia was found in 31.2% (95% CI: 0.223-0.402) and 41.9% (95% CI: 0.321-0.516) of patients with mild and moderate AD, respectively. The OR for the association between AD and sarcopenia was 2.670 (95% CI: 1.566-4.555), suggesting a robust correlation.

CONCLUSION

Sarcopenia is highly prevalent in AD patients, highlighting the need for integrated care approaches to address both cognitive and physical health issues. Further research is needed to elucidate the pathophysiological links between AD and sarcopenia.

TIMP3 deficiency accelerates UVB-induced HaCaT cell senescence by regulating ferroptosis

Prolonged exposure to ultraviolet B (UVB) light leads to the accumulation of reactive oxygen species (ROS), a key contributor to skin aging. Previous studies have demonstrated that UVB exposure results in a deficiency in the expression of TIMP3 in keratinocytes. The objective of this study was to investigate the specific role of TIMP3 in keratinocytes. UVB-treated HaCaT cells were utilized to establish a cellular photoaging model. We found that UVB significantly increased levels of ROS, promoted senescence and ferroptosis, and inhibited the expression of TIMP3 in HaCaT. This inhibition was notably alleviated by Fer-1, a ferroptosis inhibitor. In addition, the knockdown of TIMP3 in HaCaT enhanced senescence by inducing the ferroptosis. Mechanistically, UVB exposure also led to a decrease in the expression of KLF4, a transcription factor that regulated TIMP3 expression. Futhermore, UVB-induced reduced expression of KLF4 and TIMP3 in vivo. Our results suggest that deletion of the KLF4/TIMP3 axis promotes HaCaT cell senescence by facilitating the progression of ferroptosis. TIMP3 may serve as an effective therapeutic target for preventing skin photoaging.

The Potential Mechanism and the Role of Antioxidants in Mitigating Oxidative Stress in Alzheimer's Disease

Alzheimer's disease (AD) is the most prevalent cause of dementia and a significant contributor to health issues and mortality among older individuals. This condition involves a progressive deterioration in cognitive function and the onset of dementia. Recent advancements suggest that the development of AD is more intricate than its underlying brain abnormalities alone. In addition, Alzheimer's disease, metabolic syndrome, and oxidative stress are all intricately linked to one another. Increased concentrations of circulating lipids and disturbances in glucose homeostasis contribute to the intensification of lipid oxidation, leading to a gradual depletion of the body's antioxidant defenses. This heightened oxidative metabolism adversely impacts cell integrity, resulting in neuronal damage. Pathways commonly acknowledged as contributors to AD pathogenesis include alterations in synaptic plasticity, disorganization of neurons, and cell death. Abnormal metabolism of some membrane proteins is thought to cause the creation of amyloid (Aβ) oligomers, which are extremely hazardous to neurotransmission pathways, especially those involving acetylcholine. The interaction between Aβ oligomers and these neurotransmitter systems is thought to induce cellular dysfunction, an imbalance in neurotransmitter signaling, and, ultimately, the manifestation of neurological symptoms. Antioxidants have a significant impact on human health since they may improve the aging process by combating free radicals. Neurodegenerative diseases are currently incurable; however, they may be effectively managed. An appealing alternative is the utilization of natural antioxidants, such as polyphenols, through diet or dietary supplements, which offer numerous advantages. Within this framework, we have extensively examined the importance of oxidative stress in the advancement of Alzheimer's disease, as well as the potential influence of antioxidants in mitigating its effects.

Expression of Neuronal Nicotinic Acetylcholine Receptor and Early Oxidative DNA Damage in Aging Rat Brain-The Effects of Memantine

Aging and age-related neurodegenerative disorders are characterized by the dysfunction or loss of brain nicotinic acetylcholine receptors (nAChRs), and these changes may be related to other senescence markers, such as oxidative stress and DNA repair dysfunction. However, the mechanism of nAChR loss in the aging brain and the modification of this process by drugs (e.g., memantine, Mem) are not yet fully understood. To study whether the differences in nAChR expression in the rat brain occur due to aging or oxidative stress and are modulated by Mem, we analyzed nAChR subunits (at RNA and protein levels) and other biomarkers by real-time quantitative polymerase chain reaction (RQ-PCR) and Western blot validation. Twenty-one female Wistar rats were divided into four groups, depending on age, and the oldest group received injections of Mem or water with the use of intragastric catheters. We studied the cerebral grey matter (CGM), subcortical white matter (SCWM), and cerebellum (Ce). Results showed an age-related decrease of α7 nAChR mRNA level in SCWM. The α7 nAChR mRNA loss was accompanied by reduced expression of 8-oxoguanine DNA glycosylase 1 (OGG1) and an increased tumor necrosis factor alpha (TNFα) level. In the water group, we observed a higher level of α7 nAChR protein in the SCWM and Ce. Biomarker levels changed, but to a different extent depending on the brain area. Importantly, the dysfunction in antioxidative status was stopped and even regressed under Mem treatment. After two weeks of treatment, an increase in TP53 protein level and a decrease in 8-oxo-2'deoxyguanosine (8-oxo-2'dG) level were observed. We conclude that Mem administration may be protective against the senescence process by antioxidative mechanisms.

Protection against Amyloid-β Aggregation and Ferroptosis/Oxytosis Toxicity by Arylpyrazolones: Alzheimer's Disease Therapeutics

Alzheimer's disease (AD) incurs heavy costs for both the population and health systems. Nevertheless, the drugs available only provide minimal symptomatic management without much impact on the patients' quality of life. The multifactorial character of AD suggests that the development of new therapies modulating multiple biological targets contributing to disease progression will more efficiently treat the disease. The success of therapies targeting amyloid-beta oligomers suggests this is a valid approach for the development of more efficacious therapies for AD. Here, we report the design and evaluation of a series of arylpyrazolone compounds for their activity against Aβ aggregation toxicity and oxidative stress. The lead compound (1) has an EC50 value of 270 nM, good blood-brain barrier permeation in vivo and promising bioavailability. This study demonstrates the potential of these arylpyrazolones as novel, and potentially more effective, multifactorial therapies for AD.

Investigating the Impact of Sorghum on Tau Protein Phosphorylation and Mitochondrial Dysfunction Modulation in Alzheimer's Disease: An In Vitro Study

BACKGROUND

Alzheimer's disease (AD) is a progressive neurodegenerative disorder with poorly understood pathology. Elevated tau, phospho-tau and mitochondrial dysfunction are significantly correlated with an increased risk of AD and are therefore targets for disease-modifying therapy. In this study, we examined the effects of polyphenolic extracts from six different varieties of sorghum: Shawaya short black-1 (Black), IS1311C (Brown), QL33/QL36 (Red), B923296 (Red), QL12 (White), and QL33 (Red) on the attenuation of beta amyloid-induced phospho-tau levels, total tau levels, and mitochondrial dysfunction in neuronal cells.

METHOD

Tau proteins (231 (pT231), Serine- 199 (pS199), and total tau proteins (T-tau)) were detected and quantified using sandwich ELISA kits, while mitochondrial dysfunction was measured in terms of mitochondrial membrane potential (Δψm) and adenosine triphosphate (ATP) levels.

RESULTS

Almost all varieties of the sorghum extracts reduced the beta amyloid-induced pS199 and pT231 levels (p ≤ 0.05). The optimum concentration of QL33/QL36 (1000 µg/mL), QL12 (2000 µg/mL), and QL33 (2000 µg/mL) strongly attenuated the phospho-tau level. Sorghum IS1311C (750 µg/mL) showed the highest Δψm reduction (39.8%), whereas QL33 (2000 µg/mL) most strongly improved the ATP level (37.7%) (p ≤ 0.01). For both Δψm and ATP assays, the least activity was observed in sorghum B923296 at 21% and 25.5%, respectively (p ≤ 0.01).

CONCLUSIONS

The polyphenol extracts from sorghum attenuated the tau toxicity and Aβ-induced mitochondrial dysfunction in a variety- and dose-dependent manner and made a promising disease-modifying agent against AD. However, extensive research is needed to validate the efficacy of the sorghum extracts prior to animal and clinical studies.

Oxidative Stress Triggers a Pivotal Peptide Linked to Alzheimer's Disease

An aberrant recapitulation of a developmental mechanism driven by a 14 mer peptide ('T14') derived from acetylcholinesterase (AChE) has been implicated in Alzheimer's disease. T14 was suggested as an upstream driver of neurodegeneration due to its ability to stimulate the production of phosphorylated tau and amyloid beta. The activation of this mechanism in adulthood is thought to be brought upon by insult to the primarily vulnerable subcortical nuclei. Here, we show that oxidative stress, induced by high glucose and confirmed by an analysis of antioxidant enzyme mRNA expression, increased the levels of T14 peptide in PC12 cells. This increase in T14 corresponded with an increase in the mRNA expression of AChE and a decrease in the cell viability. The increase in T14 could be blocked by the cyclic form of T14, NBP14, which prevented any cytotoxic effects. These observations suggest that oxidative stress can directly trigger the inappropriate activation of T14 in the adult brain through the upregulation of Ache mRNA.

Polygonatum sibiricum polysaccharides: A promising strategy in the treatment of neurodegenerative disease

Neurodegenerative diseases (NDDs), as a neurological disorder characterised by neuronal degeneration and death, are a serious threat to human health and have long attracted attention due to their complex pathogenesis and the ineffectiveness of therapeutic drugs. Existing studies have shown that Polygonatum Sibiricum polysaccharides (PSP) have immunoregulatory, antioxidant, anti-inflammatory and other pharmacological effects, and their neuroprotective effects have been demonstrated in several scientific studies. This paper reviews the main pharmacological effects and mechanisms of PSP in the protection and treatment of NDDs, to provide a reference for the clinical application and basic research of PSP in NDDs.

Innovative pathological network-based multitarget approaches for Alzheimer's disease treatment

Alzheimer's disease (AD) is the most prevalent neurodegenerative disease and is a major health threat globally. Its prevalence is forecasted to exponentially increase during the next 30 years due to the global aging population. Currently, approved drugs are merely symptomatic, being ineffective in delaying or blocking the relentless disease advance. Intensive AD research describes this disease as a highly complex multifactorial disease. Disclosure of novel pathological pathways and their interconnections has had a major impact on medicinal chemistry drug development for AD over the last two decades. The complex network of pathological events involved in the onset of the disease has prompted the development of multitarget drugs. These chemical entities combine pharmacological activities toward two or more drug targets of interest. These multitarget-directed ligands are proposed to modify different nodes in the pathological network aiming to delay or even stop disease progression. Here, we review the multitarget drug development strategy for AD during the last decade.

Accelerated biological aging: unveiling the path to cardiometabolic multimorbidity, dementia, and mortality

Background

Cardiometabolic multimorbidity (CMM) and aging are increasing public health concerns. This prospective study used UK Biobank cohort to investigate the relationship between biological aging and the trajectory of CMM to dementia and mortality.

Methods

CMM is the coexistence of at least two cardiometabolic diseases (CMD), including stroke, ischemic heart disease, and diabetes. Biological age was calculated using the KDM-BA and PhenoAge algorithms. Accelerated aging indicated biological age advances more rapidly than chronological age.

Results

The study included 415,147 individuals with an average age of 56.5 years. During the average 11-year follow-up period, CMD-free individuals with accelerated aging had a significantly greater risk of CMD (KDM-BA, HR 1.456; PhenoAge, HR 1.404), CMM (KDM-BA, HR 1.952; PhenoAge, HR 1.738), dementia (KDM-BA, HR 1.243; PhenoAge, HR 1.212), and mortality (KDM-BA, HR 1.821; PhenoAge, HR 2.047) in fully-adjusted Cox regression models (p < 0.05 for all). Accelerated aging had adjusted HRs of 1.489 (KDM-BA) and 1.488 (PhenoAge) for CMM, 1.434 (KDM-BA) and 1.514 (PhenoAge) for dementia, and 1.943 (KDM-BA) and 2.239 (PhenoAge) for mortality in participants with CMD at baseline (p < 0.05 for all). CMM significantly mediated accelerated aging's indirect effects on dementia by 13.7% (KDM-BA, HR) and 21.6% (PhenoAge); those on mortality were 4.7% (KDM-BA) and 5.2% (PhenoAge). The population attributable-risk of Life's Essential 8 score (≥80 vs. <80) were 0.79 and 0.43 for KDM-BA and PhenoAge accelerated aging, respectively.

Conclusion

Biological aging involves the entire trajectory of CMM from a CMD-free state to CMD, to CMM, and ultimately to dementia and death. Life's Essential 8 may be a potential target to counter age acceleration.

Mind Gaps and Bone Snaps: Exploring the Connection Between Alzheimer's Disease and Osteoporosis

PURPOSE OF REVIEW

This comprehensive review discusses the complex relationship between Alzheimer's disease (AD) and osteoporosis, two conditions that are prevalent in the aging population and result in adverse complications on quality of life. The purpose of this review is to succinctly elucidate the many commonalities between the two conditions, including shared pathways, inflammatory and oxidative mechanisms, and hormonal deficiencies.

RECENT FINDINGS

AD and osteoporosis share many aspects of their respective disease-defining pathophysiology. These commonalities include amyloid beta deposition, the Wnt/β-catenin signaling pathway, and estrogen deficiency. The shared mechanisms and risk factors associated with AD and osteoporosis result in a large percentage of patients that develop both diseases. Previous literature has established that the progression of AD increases the risk of sustaining a fracture. Recent findings demonstrate that the reverse may also be true, suggesting that a fracture early in the life course can predispose one to developing AD due to the activation of these shared mechanisms. The discovery of these commonalities further guides the development of novel therapeutics in which both conditions are targeted. This detailed review delves into the commonalities between AD and osteoporosis to uncover the shared players that bring these two seemingly unrelated conditions together. The discussion throughout this review ultimately posits that the occurrence of fractures and the mechanism behind fracture healing can predispose one to developing AD later on in life, similar to how AD patients are at an increased risk of developing fractures. By focusing on the shared mechanisms between AD and osteoporosis, one can better understand the conditions individually and as a unit, thus informing therapeutic approaches and further research. This review article is part of a series of multiple manuscripts designed to determine the utility of using artificial intelligence for writing scientific reviews.

NRF2 Deficiency Promotes Ferroptosis of Astrocytes Mediated by Oxidative Stress in Alzheimer's Disease

Oxidative stress is involved in the pathogenesis of Alzheimer's disease (AD), which is linked to reactive oxygen species (ROS), lipid peroxidation, and neurotoxicity. Emerging evidence suggests a role of nuclear factor (erythroid-derived 2)-like 2 (Nrf2), a major source of antioxidant response elements in AD. The molecular mechanism of oxidative stress and ferroptosis in astrocytes in AD is not yet fully understood. Here, we aimed to investigate the mechanism by which Nrf2 regulates the ferroptosis of astrocytes in AD. We found decreased expression of Nrf2 and upregulated expression of the ROS marker NADPH oxidase 4 (NOX4) in the frontal cortex from patients with AD and in the cortex of 3×Tg mice compared to wildtype mice. We demonstrated that Nrf2 deficiency led to ferroptosis-dependent oxidative stress-induced ROS with downregulated heme oxygenase-1 and glutathione peroxidase 4 and upregulated cystine glutamate expression. Moreover, Nrf2 deficiency increased lipid peroxidation, DNA oxidation, and mitochondrial fragmentation in mouse astrocytes (mAS, M1800-57). In conclusion, these results suggest that Nrf2 deficiency promotes ferroptosis of astrocytes involving oxidative stress in AD.

Peptide-Bound Glycative, AGE and Oxidative Modifications as Biomarkers for the Diagnosis of Alzheimer's Disease-A Feasibility Study

Background: The diagnosis of Alzheimer's disease (AD) relies on core cerebrospinal fluid (CSF) biomarkers, amyloid beta (Aβ) and tau. As the brain is then already damaged, researchers still strive to discover earlier biomarkers of disease onset and the progression of AD. Glycation, advanced glycation end products (AGEs) and oxidative modifications on proteins in CSF mirror the underlying biological mechanisms that contribute to early AD pathology. However, analyzing free AGEs in the body fluids of AD patients has led to controversial results. Thus, this pilot study aimed to test the feasibility of detecting, identifying and quantifying differentially glycated, AGE or oxidatively modified peptides in CSF proteins of AD patients (n = 5) compared to a control group (n = 5). Methods: To this end, we utilized a data-dependent (DDA) nano liquid chromatography (LC) linear ion trap-Orbitrap tandem mass spectrometry (MS/MS) ) approach and database search that included over 30 glycative and oxidative modifications in four search nodes to analyze endogenous modifications on individual peptides. Furthermore, we quantified candidate peptide abundance using LC Quan. Results: We identified 299 sites of early and advanced glycation and 53 sites of oxidatively modified tryptophan. From those, we identified 17 promising candidates as putative biomarkers (receiver operating curve-area under the curve (ROC-AUC) > 0.8), albeit without statistical significance. Conclusions: The potential candidates with higher discrimination power showed correlations with established diagnostic markers, thus hinting toward the potential of those peptides as biomarkers.

Embracing complexity of (brain) aging

Aging is a multifactorial process occurring in a pathophysiological continuum which leads to organ and system functional loss. While aging is not a disease, its pathophysiological continuum predisposes to illness and multimorbidity clusters which share common biomolecular mechanisms-the pillars of aging. Brain aging and neurodegeneration share many hallmarks with other age-related diseases. The central nervous system is often the weakest link susceptible to the aging process and its deterioration, resulting in cognitive impairment and other symptoms; the aging process is associated with proteostasis collapse, stem cell exhaustion, repair mechanisms, altered brain nutrient sensing, endothelial changes, inflammation, oxidative distress, and energy unbalance, as well as other disturbances. These mechanisms are highly interwoven, and considerable research is aimed at their disentanglement and detection of their clinically relevant impact, particularly in order to identify pharmacological and non-pharmacological preventive and therapeutic strategies.

Carotenoid Supplementation for Alleviating the Symptoms of Alzheimer's Disease

Alzheimer's disease (AD) is characterized by, among other things, dementia and a decline in cognitive performance. In AD, dementia has neurodegenerative features and starts with mild cognitive impairment (MCI). Research indicates that apoptosis and neuronal loss occur in AD, in which oxidative stress plays an important role. Therefore, reducing oxidative stress with antioxidants is a natural strategy to prevent and slow down the progression of AD. Carotenoids are natural pigments commonly found in fruits and vegetables. They include lipophilic carotenes, such as lycopene, α- and β-carotenes, and more polar xanthophylls, for example, lutein, zeaxanthin, canthaxanthin, and β-cryptoxanthin. Carotenoids can cross the blood-brain barrier (BBB) and scavenge free radicals, especially singlet oxygen, which helps prevent the peroxidation of lipids abundant in the brain. As a result, carotenoids have neuroprotective potential. Numerous in vivo and in vitro studies, as well as randomized controlled trials, have mostly confirmed that carotenoids can help prevent neurodegeneration and alleviate cognitive impairment in AD. While carotenoids have not been officially approved as an AD therapy, they are indicated in the diet recommended for AD, including the consumption of products rich in carotenoids. This review summarizes the latest research findings supporting the potential use of carotenoids in preventing and alleviating AD symptoms. A literature review suggests that a diet rich in carotenoids should be promoted to avoid cognitive decline in AD. One of the goals of the food industry should be to encourage the enrichment of food products with functional substances, such as carotenoids, which may reduce the risk of neurodegenerative diseases.

Osteoporosis and Alzheimer´s disease (or Alzheimer´s disease and Osteoporosis)

Alzheimer's disease (AD) and osteoporosis are two diseases that mainly affect elderly people, with increases in the occurrence of cases due to a longer life expectancy. Several epidemiological studies have shown a reciprocal association between both diseases, finding an increase in incidence of osteoporosis in patients with AD, and a higher burden of AD in osteoporotic patients. This epidemiological relationship has motivated the search for molecules, genes, signaling pathways and mechanisms that are related to both pathologies. The mechanisms found in these studies can serve to improve treatments and establish better patient care protocols.

Gastrodin ameliorates synaptic impairment, mitochondrial dysfunction and oxidative stress in N2a/APP cells

Alzheimer's disease is characterized by abnormal β-amyloid and tau accumulation, mitochondrial dysfunction, oxidative stress, and synaptic dysfunction. Here, we aimed to assess the mechanisms and signalling pathways in the neuroprotective effect of gastrodin, a phenolic glycoside, on murine neuroblastoma N2a cells expressing human Swedish mutant APP (N2a/APP). We found that gastrodin increased the levels of presynaptic-SNAP, synaptophysin, and postsynaptic-PSD95 and reduced phospho-tau Ser396, APP and Aβ1-42 levels in N2a/APP cells. Gastrodin treatment reduced reactive oxygen species generation, lipid peroxidation, mitochondrial fragmentation and DNA oxidation; restored mitochondrial membrane potential and intracellular ATP production. Upregulated phospho-GSK-3β and reduced phospho-ERK and phospho-JNK were involved in the protective effect of gastrodin. In conclusion, we demonstrated the neuroprotective effect of gastrodin in the N2a/APP cell line by ameliorating the impairment on synaptic and mitochondrial function, reducing tau phosphorylation, Aβ1-42 levels as well as reactive oxygen species generation. These results provide new mechanistic insights into the potential effect of gastrodin in the treatment of Alzheimer's disease.

Caloric restriction leading to attenuation of experimental Alzheimer's disease results from alterations in gut microbiome

BACKGROUND

Caloric restriction (CR) might be effective for alleviating/preventing Alzheimer's disease (AD), but the biological mechanisms remain unclear. In the current study, we explored whether CR caused an alteration of gut microbiome and resulted in the attenuation of cognitive impairment of AD animal model.

METHODS

Thirty-week-old male APP/PS1 transgenic mice were used as AD models (AD mouse). CR was achieved by 30% reduction of daily free feeding (ad libitum, AL) amount. The mice were fed with CR protocol or AL protocol for six consecutive weeks.

RESULTS

We found that with CR treatment, AD mice showed improved ability of learning and spatial memory, and lower levels of Aβ40, Aβ42, IL-1β, TNF-α, and ROS in the brain. By sequencing 16S rDNA, we found that CR treatment resulted in significant diversity in composition and abundance of gut flora. At the phylum level, Deferribacteres (0.04%), Patescibacteria (0.14%), Tenericutes (0.03%), and Verrucomicrobia (0.5%) were significantly decreased in CR-treated AD mice; at the genus level, Dubosiella (10.04%), Faecalibaculum (0.04%), and Coriobacteriaceae UCG-002 (0.01%) were significantly increased in CR-treated AD mice by comparing with AL diet.

CONCLUSIONS

Our results demonstrate that the attenuation of AD following CR treatment in APP/PS1 mice may result from alterations in the gut microbiome. Thus, gut flora could be a new target for AD prevention and therapy.

Mitochondrial disorders leading to Alzheimer's disease-perspectives of diagnosis and treatment

Alzheimer's disease (AD) is a neurodegenerative disorder and the most common cause of dementia globally. The pathogenesis of AD remains still unclear. The three main features of AD are extracellular deposits of amyloid beta (Aβ) plaque, accumulation of abnormal formation hyper-phosphorylated tau protein, and neuronal loss. Mitochondrial impairment plays an important role in the pathogenesis of AD. There are problems with decreased activity of multiple complexes, disturbed mitochondrial fusion, and fission or formation of reactive oxygen species (ROS). Moreover, mitochondrial transport is impaired in AD. Mouse models in many research show disruptions in anterograde and retrograde transport. Both mitochondrial transportation and network impairment have a huge impact on synapse loss and, as a result, cognitive impairment. One of the very serious problems in AD is also disruption of insulin signaling which impairs mitochondrial Aβ removal.Discovering precise mechanisms leading to AD enables us to find new treatment possibilities. Recent studies indicate the positive influence of metformin or antioxidants such as MitoQ, SS-31, SkQ, MitoApo, MitoTEMPO, and MitoVitE on mitochondrial functioning and hence prevent cognitive decline. Impairments in mitochondrial fission may be treated with mitochondrial division inhibitor-1 or ceramide.

Fruit and Vegetable Intake and Risk of Disabling Dementia: Japan Public Health Center Disabling Dementia Study

BACKGROUND

Fruits and vegetables contain abundant amounts of antioxidant vitamins such as vitamin C, α-carotene, and β-carotene. Few prospective observational studies have investigated the effects of fruit and vegetable intake on the risk of dementia, and the results are inconsistent.

OBJECTIVES

Our aim was to examine associations between fruit and vegetable intake and the risk of disabling dementia.

METHODS

We conducted a follow-up survey within the Japan Public Health Center-based Prospective Study involving 42,643 individuals aged 50-79 y at baseline (2000-2003). Dietary fruit and vegetable intakes and related antioxidant vitamin intakes (i.e., α-carotene, β-carotene, and vitamin C) were determined using a food frequency questionnaire. The diagnosis of disabling dementia was made based on the daily living disability status related to dementia under the Japanese long-term care insurance program from 2006 to 2016. Hazard ratios and 95% confidence intervals for disabling dementia were estimated using area-stratified Cox proportional hazard models adjusted for potential confounding factors.

RESULTS

A total of 4994 cases of disabling dementia were recorded. We observed an inverse association between total fruit and vegetable intake and the risk of dementia among males and females: the multivariate hazard ratios (95% confidence intervals) for the highest compared with lowest quartiles of intake were 0.87 (0.76, 0.99) (P- trend = 0.05) among males and 0.85 (0.76, 0.94) (P- trend = 0.006) among females. Among antioxidant vitamins, vitamin C intake was inversely associated with the risk of dementia among males and females: the multivariate hazard ratios (95% confidence intervals) for the highest compared with lowest quartiles of intake were 0.71 (0.61, 0.84) (P- trend < 0.0001) among males, and 0.76 (0.67, 0.86) (P- trend < 0.0001) among females.

CONCLUSIONS

Fruit and vegetable intake and dietary intake of vitamin C may contribute to reducing the risk of disabling dementia among males and females.

Novel targets and therapies of metformin in dementia: old drug, new insights

Dementia is a devastating disorder characterized by progressive and persistent cognitive decline, imposing a heavy public health burden on the individual and society. Despite numerous efforts by researchers in the field of dementia, pharmacological treatments are limited to relieving symptoms and fail to prevent disease progression. Therefore, studies exploring novel therapeutics or repurposing classical drugs indicated for other diseases are urgently needed. Metformin, a first-line antihyperglycemic drug used to treat type 2 diabetes, has been shown to be beneficial in neurodegenerative diseases including dementia. This review discusses and evaluates the neuroprotective role of metformin in dementia, from the perspective of basic and clinical studies. Mechanistically, metformin has been shown to improve insulin resistance, reduce neuronal apoptosis, and decrease oxidative stress and neuroinflammation in the brain. Collectively, the current data presented here support the future potential of metformin as a potential therapeutic strategy for dementia. This study also inspires a new field for future translational studies and clinical research to discover novel therapeutic targets for dementia.

Design, synthesis, and evaluation of dual-target inhibitors for the treatment of Alzheimer's disease

Aβ1-42 and acetylcholinesterase (AChE) are two key therapeutic targets for Alzheimer's disease (AD). The purpose of this study is to develop a dual-target inhibitor that inhibits both of these targets by fusing the chemical structure of baicalein and donepezil. Among them, we modified the structure of baicalein to arylcoumarin, synthesized three kinds of structural compounds, and evaluated their biological activities. The results showed that compound 3b had the strongest inhibitory effect on AChE (IC50 = 0.05 ± 0.02 µM), which was better than those of donepezil and baicalein. In addition, compound 3b has a strong ability to inhibit the aggregation of Aβ1-42 and protect nerve cells, and it can also penetrate the blood-brain barrier well. Using a zebrafish behavioral analyzer test, it was found that compound 3b can alleviate the behavioral effects of AlCl3-induced zebrafish larval movement retardation, which has a certain guiding significance for simulating the movement disorders of AD patients. In summary, compound 3b is expected to become a multifunctional agent for treating and alleviating the symptoms of AD patients.

Glia Maturation Factor Beta: A Novel Neuro-Impairment Prediction Factor in Toxoplasmosis

Background

Toxoplasma gondii, a neurotropic protozoan, infects up one to third of the world population. The parasite can invade a wide variety of nucleated cells but preferably glial cells. Glia maturation factor β (GMFβ), a 17KD protein expressed at high levels in the central nervous system is predominantly related to neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and Multiple sclerosis. We aimed to determine the expression level of GMFβ and its relation to other pro-inflammatory factors (IL33, SDF1, and CCL2) on T. gondii infected human neuroblastoma cell line.

Methods

The human neuroblastoma (SK_NMC C535) cell line was infected by 5×106 (1:1 ratio). The supernatant was collected after cell lysis and centrifugation. Total RNA was extracted using the Yekta Tajhiz RNA extraction kit. cDNA was synthesized based on RevertAid First Strand cDNA Synthesis Kit manufacturer's protocol (Parstous, cDNA synthesis kit, Iran). The specificity of each primer pair (GMFβ, IL33, SDF1, and CCL2) was provided by NCBI BLAST. Gene expression level was measured using Real-Time PCR. All experiments were conducted at the Hamadan University of Medical Sciences, western Iran in 2022.

Results

The GMFβ increased significantly up to 1.35-fold (P=0.007). The increase in GMFβ expression in neuroblastoma cells was consistent with the increase in pro-inflammatory factors (CCL2 (0.47), IL33 (0.152) and, SDF1 (1.33)).

Conclusion

GMFβ upregulation can be a novel indicator of the destruction of nerve cells.

Development of dietary small molecules as multi-targeting treatment strategies for Alzheimer's disease

Cognitive dysfunction can occur both in normal aging and age-related neurological disorders, such as mild cognitive impairment and Alzheimer's disease (AD). These disorders have few treatment options due to side effects and limited efficacy. New approaches to slow cognitive decline are urgently needed. Dietary interventions (nutraceuticals) have received considerable attention because they exhibit strong neuroprotective properties and may help prevent or minimize AD symptoms. Biological aging is driven by a series of interrelated mechanisms, including oxidative stress, neuroinflammation, neuronal apoptosis, and autophagy, which function through various signaling pathways. Recent clinical and preclinical studies have shown that dietary small molecules derived from natural sources, including flavonoids, carotenoids, and polyphenolic acids, can modulate oxidative damage, cognitive impairments, mitochondrial dysfunction, neuroinflammation, neuronal apoptosis, autophagy dysregulation, and gut microbiota dysbiosis. This paper reviews research on different dietary small molecules and their bioactive constituents in the treatment of AD. Additionally, the chemical structure, effective dose, and specific molecular mechanisms of action are comprehensively explored. This paper also discusses the advantages of using nanotechnology-based drug delivery, which significantly enhances oral bioavailability, safety, and therapeutic effect, and lowers the risk of adverse effects. These agents have considerable potential as novel and safe therapeutic agents that can prevent and combat age-related AD.

Association of 8-hydroxy-2'-deoxyguanosine with motoric cognitive risk in elderly Chinese people: RUGAO longevity and aging cross-sectional study

BACKGROUND

Motor cognitive risk syndrome (MCR) represents a critical pre-dementia and disability state characterized by a combination of objectively measured slow walking speed and subjective memory complaints (SMCs). This study aims to identify risk factors for MCR and investigate the relationship between plasma levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG) and MCR among Chinese community-dwelling elderly populations.

METHODS

A total of 1312 participants were involved in this study based on the data of the Rugao Longevity and Aging Study (RuLAS). The MCR was characterized by SMCs and slow walking speed. The SCCs were defined as a positive answer to the question 'Do you feel you have more problems with memory than most?' in a 15-item Geriatric Depression Scale. Slow walking speed was determined by one standard deviation or more below the mean value of the patient's age and gender group. The plasma of 8-OHdG were measured by a technician in the biochemistry laboratory of the Rugao People's Hospital during the morning of the survey.

RESULTS

The prevalence of MCR was found to be 7.9%. After adjusting for covariates, significant associations with MCR were observed in older age (OR 1.057; p = 0.018), history of cerebrovascular disease (OR 2.155; p = 0.010), and elevated 8-OHdG levels (OR 1.007; p = 0.003).

CONCLUSIONS

This study indicated the elevated plasma 8-OHdG is significantly associated with increased MCR risk in the elderly, suggesting its potential as a biomarker for early detection and intervention in MCR. This finding underscores the importance of monitoring oxidative DNA damage markers in predicting cognitive and motor function declines, offering new avenues for research and preventive strategies in aging populations.

Association Between Self-Perception of Aging and Long-Term Mortality in Elderly Patients with Hypertension in Rural China: A Possible Beneficial Effect of Nut Intake

Purpose

Previous research has consistently shown that self-perception of aging (SPA) is an important predictor of health and longevity, while Chinese rural elderly patients with hypertension had poorer SPA. Whether it was associated with their mortality kept unknown. The objective of this study was to investigate the long-term mortality and analyze the association between SPA and this mortality in the specific context of rural elderly patients with hypertension.

Patients and Methods

This study is a longitudinal investigation of the mortality in elderly patients with hypertension in rural Suzhou, China. Sociodemographic and clinical data, SPA, and six-year mortality were investigated. We used binary logistic regression and subgroup analyses to assess the effect of SPA at baseline on six-year mortality.

Results

A total of 280 hypertensive patients aged 60 years and older participated in the study, of whom 21 died, with a six-year mortality rate of 7.5%. After controlling for covariates, the "Emotional representation" dimension (OR=2.824, 95% CI:1.034-7.712) in SPA remained a risk factor for death. In subgroup analyses of the group aged 75 years and older, high scores on the "Timeline cyclical" (OR=14.125, 95% CI: 1.258-158.593) and "Emotional representations" (OR=2.567, 95% CI:1.066-6.182) dimensions were associated with a higher risk of death, while weekly nut intake may have mitigated the negative SPA effect on mortality.

Conclusion

Poorer self-perception of aging was associated with a high risk of mortality in rural elderly patients with hypertension, while the habit of weekly nut intake might help reduce this risk in the group aged 75 years or older.

Emerging role and mechanism of HACE1 in the pathogenesis of neurodegenerative diseases: A promising target

HACE1 is a member of the HECT domain-containing E3 ligases with 909 amino acid residues, containing N-terminal ankyrin-repeats (ANK) and C-terminal HECT domain. Previously, it was shown that HACE1 is inactive in human tumors and plays a crucial role in the initiation, progression, and invasion of malignant tumors. Recent studies indicated that HACE1 might be closely involved in neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and Huntington's disease. HACE1 interacts with its substrates, including Ras-related C3 botulinum toxin substrate 1 (Rac1), nuclear factor erythroid 2-related factor 2 (Nrf2), tumor necrosis factor receptor (TNFR), and optineurin (OPTN), through which participates in several pathophysiological processes, such as oxidative stress, autophagy and inflammation. Therefore, in this review, we elaborately describe the essential substrates of HACE1 and illuminate the pathophysiological processes by which HACE1 is involved in neurodegenerative diseases. We provide a new molecular target for neurodegenerative diseases.

Aging hallmarks, biomarkers, and clocks for personalized medicine: (re)positioning the limelight

The rapidly increasing aging prevalence, complexity, and heterogeneity pose the scientific and medical communities in front of challenges. These are delivered by gaps between basic and translational research, as well as between clinical practice guidelines to improve survival and absence of evidence on personalized strategies to improve functions, wellbeing and quality of life. The triumphs of aging science sheding more and more light on mechanisms of aging as well as those of medical and technological progress to prolong life expectancy are clear. Currently, and in the next two to three decades, all efforts must be put in a closer interdisciplinary dialogue between biogerontologists and geriatricians to enable real-life measures of aging phenotypes to be used to uncover the physiological - and therefore translational - relevance of newly discovered aging clocks, biomarkers, and hallmarks.

Association of adherence to the Chinese version of the MIND diet with reduced cognitive decline in older Chinese individuals: Analysis of the Chinese Longitudinal Healthy Longevity Survey

BACKGROUND

Current evidence suggests that the Mediterranean-Dietary Approaches to Stop Hypertension (DASH) diet intervention for Neurodegenerative Delay (MIND) is associated with a reduced risk of cognitive impairment among North American and Oceanian populations. However, there has been limited exploration of whether this association extends to the Asian population. This study aimed to assess the correlation between the Chinese version of the MIND (cMIND) diet and cognitive impairment in older Chinese individuals.

METHODS

We utilized data from the 2008 wave of the Chinese Longitudinal Healthy Longevity Survey. Participants aged ≥65 years with normal cognitive function at baseline were enrolled. The cMIND diet score (cMINDDS) was calculated by assessing dietary patterns based on survey responses. The Chinese version of the Mini-Mental State Examination (MMSE) was employed to diagnose cognitive impairment in participants. We stratified the analysis by cMINDDS and conducted additional sensitivity analyses.

RESULTS

The cohort consisted of 6411 participants. Over a 3-year follow-up, 1165 (18.6%) individuals who initially had normal cognitive function developed cognitive impairment. A linear association was observed between cMINDDS and cognitive impairment. The increased cMINDDS was associated with a reduced risk of cognitive impairment (quartile 1 vs. quartile 4: the adjusted odds ratio [OR] = 0.77, 95% confidence interval [CI]: [0.60, 0.97], p trend = 0.023). Regarding food composition, higher consumption of fresh fruits and nuts was associated with a decreased risk of cognitive impairment (OR = 0.77, 95% CI: [0.66, 0.89] and OR = 0.70, 95% CI [0.58, 0.86], respectively).

CONCLUSIONS

Adherence to the cMIND diet was associated with lower risks of cognitive impairment in older Chinese individuals. The cMIND diet, based on the MIND dietary pattern, could serve as a preventive measure against cognitive impairment.

The WMI Rat of Premature Cognitive Aging Presents Intrinsic Vulnerability to Oxidative Stress in Primary Neurons and Astrocytes Compared to Its Nearly Isogenic WLI Control

The primary neuronal and astrocyte culture described here is from the stress-hyperreactive Wistar Kyoto (WKY) More Immobile (WMI) rat with premature aging-related memory deficit, and its nearly isogenic control, the Less Immobile (WLI) strain. Primary WMI hippocampal neurons and cortical astrocytes are significantly more sensitive to oxidative stress (OS) generated by administration of H2O2 compared to WLI cells as measured by the trypan blue cell viability assay. Intrinsic genetic vulnerability is also suggested by the decreased gene expression in WMI neurons of catalase (Cat), and in WMI cortical astrocytes of insulin-like growth factor 2 (Igf2), synuclein gamma (Sncg) and glutathione peroxidase 2 (Gpx2) compared to WLI. The expressions of several mitochondrial genes are dramatically increased in response to H2O2 treatment in WLI, but not in WMI cortical astrocytes. We propose that the vulnerability of WMI neurons to OS is due to the genetic differences between the WLI and WMI. Furthermore, the upregulation of mitochondrial genes may be a compensatory response to the generation of free radicals by OS in the WLIs, and this mechanism is disturbed in the WMIs. Thus, this pilot study suggests intrinsic vulnerabilities in the WMI hippocampal neurons and cortical astrocytes, and affirm the efficacy of this bimodal in vitro screening system for finding novel drug targets to prevent oxidative damage in illnesses.

Oxidative stress in Alzheimer's disease: current knowledge of signaling pathways and therapeutics

Alzheimer's disease's pathophysiology is still a conundrum. Growing number of evidences have elucidated the involvement of oxidative stress in the pathology of AD rendering it a major target for therapeutic development. Reactive oxygen species (ROS) generated by altered mitochondrial function, dysregulated electron transport chain and other sources elevate aggregated Aβ and neurofibrillary tangles which further stimulating the production of ROS. Oxidative stress induced damage to lipids, proteins and DNA result in neuronal death which leads to AD. In addition, oxidative stress induces apoptosis that is triggered by the modulation of ERK1/2 and Nrf2 pathway followed by increased GSK-3β expression and decreased PP2A activity. Oxidative stress exaggerates disease condition by interfering with various signaling pathways like RCAN1, CREB/ERK, Nrf2, PP2A, NFκB and PI3K/Akt. Studies have reported the role of TNF-α in oxidative stress stimulation that has been regulated by drugs like etanercept increasing the level of anti-oxidants. Other drugs like pramipexole, memantine, carvedilol, and melatonin have been reported to activate CREB/RCAN1 and Nrf2 pathways. In line with this, epigallocatechin gallate and genistein also target Nrf2 and CREB pathway leading to activation of downstream pathways like ARE and Keap1 which ameliorate oxidative stress condition. Donepezil and resveratrol reduce oxidative stress and activate AMPK pathway along with PP2A activation thus promoting tau dephosphorylation and neuronal survival. This study describes in detail the role of oxidative stress in AD, major signaling pathways involving oxidative stress induced AD and drugs under development targeting these pathways which may aid in therapeutic advances for AD.

Neuro-protective Effect of Acetyl-11-keto-β-boswellic Acid in a Rat Model of Scopolamine-induced Cholinergic Dysfunction

BACKGROUND

Acetyl-11-keto-β-boswellic acid (AKBA) is a major component of the oleo-gum resin of B. serrata with multiple pharmacological activities. The objective of this study was to explore the underlying mechanisms of neuroprotective potential of AKBA against scopolamine-mediated cholinergic dysfunction and memory deficits in rats.

METHODS

The rats received AKBA (2.5, 5, and 10 mg/kg, oral) for 21 days. In the third week, scopolamine was administered 30 min before the Morris water maze and passive avoidance tests. In order to perform biochemical assessments, the hippocampus and prefrontal cortex were extracted from the rats euthanized under deep anesthesia.

RESULTS

In the MWM test, treatment with AKBA (5 and 10 mg/kg) decreased the latency and distance to find the platform. Moreover, in the PA test, AKBA remarkably increased latency to darkness and stayed time in lightness while decreasing the frequency of entry and time in the darkness. According to the biochemical assessments, AKBA decreased acetylcholinesterase activity and malondialdehyde levels while increasing antioxidant enzymes and total thiol content. Furthermore, AKBA administration restored the hippocampal mRNA and protein levels of brain-derived neurotrophic factor (BDNF) and mRNA expression of B-cell lymphoma (Bcl)- 2 and Bcl-2- associated X genes in brain tissue of scopolamine-injured rats.

CONCLUSION

The results suggested the effectiveness of AKBA in preventing learning and memory dysfunction induced by scopolamine. Accordingly, these protective effects might be produced by modulating BDNF, cholinergic system function, oxidative stress, and apoptotic markers.

Effect and Mechanism of Rapamycin on Cognitive Deficits in Animal Models of Alzheimer's Disease: A Systematic Review and Meta-analysis of Preclinical Studies

Background

Alzheimer's disease (AD), the most common form of dementia, remains long-term and challenging to diagnose. Furthermore, there is currently no medication to completely cure AD patients. Rapamycin has been clinically demonstrated to postpone the aging process in mice and improve learning and memory abilities in animal models of AD. Therefore, rapamycin has the potential to be significant in the discovery and development of drugs for AD patients.

Objective

The main objective of this systematic review and meta-analysis was to investigate the effects and mechanisms of rapamycin on animal models of AD by examining behavioral indicators and pathological features.

Methods

Six databases were searched and 4,277 articles were retrieved. In conclusion, 13 studies were included according to predefined criteria. Three authors independently judged the selected literature and methodological quality. Use of subgroup analyses to explore potential mechanistic effects of rapamycin interventions: animal models of AD, specific types of transgenic animal models, dosage, and periodicity of administration.

Results

The results of Morris Water Maze (MWM) behavioral test showed that escape latency was shortened by 15.60 seconds with rapamycin therapy, indicating that learning ability was enhanced in AD mice; and the number of traversed platforms was increased by 1.53 times, indicating that the improved memory ability significantly corrected the memory deficits.

CONCLUSIONS

Rapamycin therapy reduced age-related plaque deposition by decreasing AβPP production and down-regulating β-secretase and γ-secretase activities, furthermore increased amyloid-β clearance by promoting autophagy, as well as reduced tau hyperphosphorylation by up-regulating insulin-degrading enzyme levels.

Oxidative damage in neurodegeneration: roles in the pathogenesis and progression of Alzheimer disease

Alzheimer disease (AD) is associated with multiple etiologies and pathological mechanisms, among which oxidative stress (OS) appears as a major determinant. Intriguingly, OS arises in various pathways regulating brain functions, and it seems to link different hypotheses and mechanisms of AD neuropathology with high fidelity. The brain is particularly vulnerable to oxidative damage, mainly because of its unique lipid composition, resulting in an amplified cascade of redox reactions that target several cellular components/functions ultimately leading to neurodegeneration. The present review highlights the "OS hypothesis of AD," including amyloid beta-peptide-associated mechanisms, the role of lipid and protein oxidation unraveled by redox proteomics, and the antioxidant strategies that have been investigated to modulate the progression of AD. Collected studies from our groups and others have contributed to unraveling the close relationships between perturbation of redox homeostasis in the brain and AD neuropathology by elucidating redox-regulated events potentially involved in both the pathogenesis and progression of AD. However, the complexity of AD pathological mechanisms requires an in-depth understanding of several major intracellular pathways affecting redox homeostasis and relevant for brain functions. This understanding is crucial to developing pharmacological strategies targeting OS-mediated toxicity that may potentially contribute to slow AD progression as well as improve the quality of life of persons with this severe dementing disorder.

Pelvic irradiation induces behavioural and neuronal damage through gut dysbiosis in a rat model

Radiation exposure can cause gut dysbiosis and there is a positive correlation between gut microbial imbalance and radiation-induced side effects in cancer patients. However, the influence of radiation on the gut-brain axis (GBA) and its neurological consequences are not well understood. Therefore, this study aimed to investigate the impact of pelvic irradiation on gut microbiota and the brain. Sprague Dawley rats were irradiated with a single dose of 6 Gy, and faecal samples were collected at different time points (7 and 12-days post-irradiation) for microbial analysis. Behavioural, histological, and gene expression analysis were performed to assess the effect of microbial dysbiosis on the brain. The findings indicated alterations in microbial diversity, disrupted intestinal morphology and integrity, neuronal death-related brain changes, neuroinflammation and reduced locomotor activity. Hippocampal gene expression analysis also showed a reduced expression of neural plasticity-related genes. Overall, this study demonstrated that pelvic irradiation affects gut microbiota, intestinal morphology, integrity, brain neuronal maturation, neural plasticity gene expression, and behaviour.

Emerging trends and hotspots of Nuclear factor erythroid 2-related factor 2 in nervous system diseases

BACKGROUND

The Nuclear factor erythroid 2-related factor 2 (NRF2) transcription factor has attracted much attention in the context of neurological diseases. However, none of the studies have systematically clarified this field's research hotspots and evolution rules.

AIM

To investigate the research hotspots, evolution patterns, and future research trends in this field in recent years.

METHODS

We conducted a comprehensive literature search in the Web of Science Core Collection database using the following methods: (((((TS=(NFE2 L2)) OR TS=(Nfe2 L2 protein, mouse)) OR TS=(NF-E2-Related Factor 2)) OR TS=(NRF2)) OR TS=(NFE2L2)) OR TS=(Nuclear factor erythroid2-related factor 2) AND (((((((TS=(neurological diseases)) OR TS=(neurological disorder)) OR TS=(brain disorder)) OR TS=(brain injury)) OR TS=(central nervous system disease)) OR TS=(CNS disease)) OR TS=(central nervous system disorder)) OR TS=(CNS disorder) AND Language = English from 2010 to 2022. There are just two forms of literature available: Articles and reviews. Data were processed with the software Cite-Space (version 6.1. R6).

RESULTS

We analyzed 1884 articles from 200 schools in 72 countries/regions. Since 2015, the number of publications in this field has increased rapidly. China has the largest number of publications, but the articles published in the United States have better centrality and H-index. Among the top ten authors with the most published papers, five of them are from China, and the author with the most published papers is Wang Handong. The institution with the most articles was Nanjing University. To their credit, three of the top 10 most cited articles were written by Chinese scholars. The keyword co-occurrence map showed that "oxidative stress", "NRF2", "activation", "expression" and "brain" were the five most frequently used keywords.

CONCLUSION

Research on the role of NRF2 in neurological diseases continues unabated. Researchers in developed countries published more influential papers, while Chinese scholars provided the largest number of articles. There have been numerous studies on the mechanism of NRF2 transcription factor in neurological diseases. NRF2 is also emerging as a potentially effective target for the treatment of neurological diseases. However, despite decades of research, our knowledge of NRF2 transcription factor in nervous system diseases is still limited. Further studies are needed in the future.

Association of dietary variety with the risk for dementia: the Yabu cohort study

OBJECTIVE

The consumption of various foods is internationally recommended in healthy diet although the association between dietary variety and incident dementia is unknown. We aimed to examine the association between dietary variety and the incidence of disabling dementia in older Japanese adults.

DESIGN

We conducted a prospective cohort study. Dietary variety was assessed based on the Dietary Variety Score (DVS). DVS was assessed by counting the number of ten food components (meat, fish/shellfish, eggs, milk, soyabean products, green/yellow vegetables, potatoes, fruit, seaweed and fats/oils) that were consumed almost daily using a FFQ. Participants were categorised into low (0-2 points), middle (3-4 points) and high (5-10 points) groups based on the DVS. Data on newly diagnosed disabling dementia were retrieved from the public long-term care insurance database. Cox proportional hazards regression was used to estimate hazard ratios (HR) with 95 % CI.

SETTING

Yabu cohort study, Japan.

PARTICIPANTS

A total of 4972 community-dwelling adults aged 65 years or older.

RESULTS

During the median follow-up of 6·8 years, 884 participants were newly diagnosed with disabling dementia. After adjusting for confounders, the multivariable-adjusted HR for incident disabling dementia was 0·82 (95 % CI, 0·69, 0·97) for participants in the highest DVS category compared with those in the lowest DVS category (Pfor trend = 0·019).

CONCLUSIONS

A higher dietary variety is associated with a reduced risk of disabling dementia in older Japanese adults. These results have potential implications for the development of effective public nutritional approaches to prevent dementia in older adults.

Oxidative stress as a bridge between age and stroke: A narrative review

Stroke is the third most common cause of death globally and a leading cause of disability. The cellular and molecular changes following stroke and causes of neuronal death are not fully understood, and there are few effective treatments currently available. A rapid increase in the levels of reactive oxygen species (ROS) post stroke can overwhelm antioxidant defenses and trigger a series of pathophysiologic events including the inflammatory response, blood-brain barrier (BBB) disruption, apoptosis, and autophagy, ultimately leading to neuron degeneration and apoptosis. It is thought that beyond a certain age, the ROS accumulation resulting from stroke increases the risk of morbidity and mortality. In the present review, we summarize the role of oxidative stress (OS) as a link between aging and stroke pathogenesis. We also discuss how antioxidants can play a beneficial role in the prevention and treatment of stroke by eliminating harmful ROS, delaying aging, and alleviating damage to neurons.

Hydrocortisone Mitigates Alzheimer's-Related Cognitive Decline through Modulating Oxidative Stress and Neuroinflammation

Alzheimer's disease (AD), an age-related degenerative disorder, is characterized by β-amyloid deposition, abnormal phosphorylation of tau proteins, synaptic dysfunction, neuroinflammation, and oxidative stress. Despite extensive research, there are no medications or therapeutic interventions to completely treat and reverse AD. Herein, we explore the potential of hydrocortisone (HC), a natural and endogenous glucocorticoid known to have potent anti-inflammatory properties, in an Aβ1-42-induced AD mouse model. Our investigation highlights the beneficial effects of HC administration on cognitive impairment, synaptic function enhancement, and neuronal protection in Aβ1-42-induced AD mice. Notably, HC treatment effectively suppresses the hyperactivation of microglia and astrocytes, leading to a reduction in proinflammatory factors and alleviation of neuroinflammation. Furthermore, HC intervention demonstrates the capacity to mitigate the generation of ROS and oxidative stress. These compelling findings underscore the potential therapeutic application of HC in AD and present promising opportunities for its utilization in AD prevention and treatment. The implications drawn from our findings indicate that hydrocortisone holds promise as a viable candidate for adjunctive use with other anti-AD drugs for the clinical management of patients presenting with moderate to severe AD.

Decoding Angiotensin Receptors: TOMAHAQ-Based Detection and Quantification of Angiotensin Type-1 and Type-2 Receptors

Background The renin-angiotensin system plays a crucial role in human physiology, and its main hormone, angiotensin, activates 2 G-protein-coupled receptors, the angiotensin type-1 and type-2 receptors, in almost every organ. However, controversy exists about the location, distribution, and expression levels of these receptors. Concerns have been raised over the low sensitivity, low specificity, and large variability between lots of commercially available antibodies for angiotensin type-1 and type-2 receptors, which makes it difficult to reconciliate results of different studies. Here, we describe the first non-antibody-based sensitive and specific targeted quantitative mass spectrometry assay for angiotensin receptors. Methods and Results Using a technique that allows targeted analysis of multiple peptides across multiple samples in a single mass spectrometry analysis, known as TOMAHAQ (triggered by offset, multiplexed, accurate mass, high resolution, and absolute quantification), we have identified and validated specific human tryptic peptides that permit identification and quantification of angiotensin type-1 and type-2 receptors in biological samples. Several peptide sequences are conserved in rodents, making these mass spectrometry assays amenable to both preclinical and clinical studies. We have used this method to quantify angiotensin type-1 and type-2 receptors in postmortem frontal cortex samples of older adults (n=28) with Alzheimer dementia. We correlated levels of angiotensin receptors to biomarkers classically linked to renin-angiotensin system activation, including oxidative stress, inflammation, amyloid-β load, and paired helical filament-tau tangle burden. Conclusions These robust high-throughput assays will not only catalyze novel mechanistic studies in the angiotensin research field but may also help to identify patients with an unbalanced angiotensin receptor distribution who would benefit from angiotensin receptor blocker treatment.

The Importance of Antioxidant Activity for the Health-Promoting Effect of Lycopene

Lycopene is a compound of colored origin that shows strong antioxidant activity. The positive effect of lycopene is the result of its pleiotropic effect. The ability to neutralize free radicals via lycopene is one of the foundations of its pro-health effect, including the ability to inhibit the development of many civilization diseases. Therefore, this study focuses on the importance of the antioxidant effect of lycopene in inhibiting the development of diseases such as cardiovascular diseases, diseases within the nervous system, diabetes, liver diseases, and ulcerative colitis. According to the research mentioned, lycopene supplementation has significant promise for the treatment of illnesses marked by chronic inflammation and oxidative stress. However, the majority of the supporting data for lycopene's health benefits comes from experimental research, whereas the evidence from clinical studies is both scarcer and less certain of any health benefits. Research on humans is still required to establish its effectiveness.

Roles of Non-Coding RNA in Alzheimer's Disease Pathophysiology

Alzheimer's disease (AD) is a chronic neurodegenerative disorder that is accompanied by deficits in memory and cognitive functions. The disease is pathologically characterised by the accumulation and aggregation of an extracellular peptide referred to as amyloid-β (Aβ) in the form of amyloid plaques and the intracellular aggregation of a hyperphosphorelated protein tau in the form of neurofibrillary tangles (NFTs) that cause neuroinflammation, synaptic dysfunction, and oxidative stress. The search for pathomechanisms leading to disease onset and progression has identified many key players that include genetic, epigenetic, behavioural, and environmental factors, which lend support to the fact that this is a multi-faceted disease where failure in various systems contributes to disease onset and progression. Although the vast majority of individuals present with the sporadic (non-genetic) form of the disease, dysfunctions in numerous protein-coding and non-coding genes have been implicated in mechanisms contributing to the disease. Recent studies have provided strong evidence for the association of non-coding RNAs (ncRNAs) with AD. In this review, we highlight the current findings on changes observed in circular RNA (circRNA), microRNA (miRNA), short interfering RNA (siRNA), piwi-interacting RNA (piRNA), and long non-coding RNA (lncRNA) in AD. Variations in these ncRNAs could potentially serve as biomarkers or therapeutic targets for the diagnosis and treatment of Alzheimer's disease. We also discuss the results of studies that have targeted these ncRNAs in cellular and animal models of AD with a view for translating these findings into therapies for Alzheimer's disease.

Exploring the Causal Relationship Between Telomere Biology and Alzheimer's Disease

Telomeres, also known as the "protective caps" of our chromosomes, shorten with each cell cycle due to the end replication problem. This process, termed telomere attrition, is associated with many age-related disorders, such as Alzheimer's disease (AD). Despite the numerous studies conducted in this field, the role of telomere attrition in the onset of the disease remains unclear. To investigate the causal relationship between short telomeres and AD, this review aims to highlight the primary factors that regulate telomere length and maintain its integrity, with an additional outlook on the role of oxidative stress, which is commonly associated with aging and molecular damage. Although some findings thus far might be contradictory, telomere attrition likely plays a crucial role in the progression of AD due to its close association with oxidative stress. The currently available treatments for AD are only symptomatic without affecting the progression of the disease. The components of telomere biology discussed in this paper have previously been studied as an alternative treatment option for several diseases and have exhibited promising in vitro and in vivo results. Hence, this should provide a basis for future research to develop a potential therapeutic strategy for AD. (Created with BioRender.com).

Discovery of drug lead compounds for Anti-Alzheimer's disease on the basis of synaptic plasticity

Alzheimer's disease (AD) is a progressive neurodegenerative disease commonly seen in the middle-aged and the elder. Its clinical presentations are mainly memory impairment and cognitive impairment. Its cardinal pathological features are the deposition of extracellular Amyloid-β (Aβ), intracellular neurofibrillary tangles and synaptic dysfunction. The etiology of AD is complex and the pathogenesis remains unclear. Having AD would lead to awful living experience of it's patients, which may be a burden to the patient even to the public health care system. However, there are no certain cure for AD. Thus it's significant for both medical value and social meaning to find the way to cure or prevent AD and to research on the pathogenesis of AD. In this work, the molecular docking technology, pharmacokinetic analysis and pharmacological experiments were employed to analyse the natural active compounds and the mechanisms against AD based on the synaptic plasticity. A total of seven target proteins related to the synaptic plasticity and 44 natural active compounds with potential to enhance the synaptic plasticity were obtained through a literature review and network pharmacological analysis. Computer-Aided Drug Design (CADD) method was used to dock the anti-AD key target proteins with the 44 compounds. The compounds with good binding effect were screened. Three anti-AD active compounds based on the synaptic plasticity were obtained, including Curcumin, Withaferin A and Withanolide A. In addition, pharmacological experiments were carried out on Withaferin A and Withanolide A based on its good docking results. The experimental results showed that Withaferin A has good anti-AD potential and great potential to enhance synaptic plasticity. The anti-AD effect can be achieved through a multi-target synergistic mechanism.

The Potential of Fasting-Mimicking Diet as a Preventive and Curative Strategy for Alzheimer's Disease

This review examines the potential of fasting-mimicking diets (FMDs) in preventing and treating Alzheimer's disease (AD). FMDs are low-calorie diets that mimic the physiological and metabolic effects of fasting, including the activation of cellular stress response pathways and autophagy. Recent studies have shown that FMDs can reduce amyloid-beta accumulation, tau phosphorylation, and inflammation, as well as improve cognitive function in animal models of AD. Human studies have also reported improvements in AD biomarkers, cognitive functions, and subjective well-being measures following FMDs. However, the optimal duration and frequency of FMDs and their long-term safety and efficacy remain to be determined. Despite these uncertainties, FMDs hold promise as a non-pharmacological approach to AD prevention and treatment, and further research in this area is warranted.

Intranasal in situ gelling liquid crystal for delivery of resveratrol ameliorates memory and neuroinflammation in Alzheimer's disease

Alzheimer's disease (AD) is an illness that affects people aged 65 or older and affects around 6.5 million in the United States. Resveratrol is a chemical obtained from natural products and it exhibits biological activity based on inhibiting the formation, depolymerization of the amyloid, and decreasing neuroinflammation. Due to the insolubility of this compound; its incorporation in surfactant-based systems was proposed to design an intranasal formulation. A range of systems has been produced by mixing oleic acid, CETETH-20 and water. Polarised light microscopy (PLM), small angle x-ray scattering (SAXS) and transmission electron microscopy (TEM) confirm the initial liquid formulation (F) presented as microemulsion (ME). After dilution, the gelled systems were characterized as hexagonal mesophase and they showed feasibility proprieties. Pharmacological assays performed after intranasal administration showed the ability to improve learning and memory in animals, as well as remission of neuroinflammation via inhibition of interleukin.