Potential of Sorghum Polyphenols to Prevent and Treat Alzheimer's Disease: A Review Article

The identification of active compounds and therapeutic properties of fermented and non-fermented red sorghum for the treatment of Alzheimer's dementia

Sorghum is a promising treatment for Alzheimer's disease (AD), due to its rich antioxidant and anti-inflammatory qualities. Fermentation may also affect nutritional values. Therefore, the purpose of this study was to discover the phenolic and flavonoid chemicals found in both fermented and non-fermented red sorghum, as well as their potential therapeutic uses for AD. L. fermentum, and L. reuteri, and/or L. plantarum and L. casei were used to ferment samples of sorghum. The rats were grouped into five groups, healthy animals, and rats with Alzheimer's receiving 200 mg/kg of saline, non-fermented sorghum, and fermented sorghum fermented with L. fermentum and L. reuteri, as well as L. plantarum and L. casei. Various assessments were conducted, including evaluations of behavioral responses, antioxidant responses, inflammatory responses, acetylcholine levels and acetylcholine esterase, and bacterial populations in stool. P-hydroxybenzoic acid, eriodictyo naringenin, and apigenin were significantly higher in fermented samples, while glycerols were higher in non-fermented samples. The induction of Alzheimer's led to decrease step-through latency, time in target zone, FRAP, acetylcholine levels, Bifidobacterium population and lactobacillus population, while increased escape latency, platform location latency, MDA levels, IL-6, TNF-α, acetylcholine esterase, and coliform population (P = 0.001). The administration of both non-fermented sorghum and fermented sorghum demonstrated the potential to reverse the effects of AD, with a notably higher efficacy observed in the fermented samples compared to the non-fermented ones. In conclusion, fermentation exerted significant effects on the bioactive compounds the administration of fermented sorghum resulted in improved behavioral responses, characterized by a reduction in oxidation, inflammation and microbial population.

Network pharmacology study on fermented soybeans for the prevention of Alzheimer's disease in older individuals

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by the disruption of synaptic communication among millions of neurons. Recent research has highlighted the potential therapeutic effectiveness of natural polyphenolic compounds in addressing AD. Soybeans are abundant in polyphenols, and their polyphenolic composition undergoes significant alteration through fermentation by Eurotium cristatum. Through comprehensive database searches, we identified active components within fermented soybean polyphenols and genes associated with AD. Subsequently, we utilized Venn diagrams to analyze the overlap between AD-related genes and these components. Furthermore, we visualized the network between intersecting targets and proteins using Cytoscape software. The anti-AD effects of soybeans were further explored through comprehensive analysis, including protein-protein interaction analysis, pathway enrichment analysis, and molecular docking studies. Our investigation unveiled 6-hydroxydaidzein as a major component of fermented soybean polyphenols, shedding light on its potential therapeutic significance in combating AD. The intersection between target proteins of fermented soybeans and disease-related targets in AD comprised 34 genes. Protein-protein interaction analysis highlighted key potential targets, including glyceraldehyde-3-phosphate dehydrogenase (GAPDH), glycogen synthase kinase 3 beta (GSK3B), amyloid precursor protein (APP), cyclin-dependent kinase 5 (CDK5), and beta-site APP cleaving enzyme 1 (BACE1). Molecular docking results demonstrated a robust binding effect between major components from fermented soybeans and the aforesaid key targets implicated in AD treatment. These findings suggest that fermented soybeans demonstrate a degree of efficacy and present promising prospects in the prevention of AD.

Sorghum Grain Polyphenolic Extracts Demonstrate Neuroprotective Effects Related to Alzheimer's Disease in Cellular Assays

Sorghum grain contains high levels and a diverse profile of polyphenols (PPs), which are antioxidants known to reduce oxidative stress when consumed in the diet. Oxidative stress leading to amyloid-β (Aβ) aggregation, neurotoxicity, and mitochondrial dysfunction is implicated in the pathogenesis of Alzheimer's disease (AD). Thus, PPs have gained attention as possible therapeutic agents for combating AD. This study aimed to (a) quantify the phenolic compounds (PP) and antioxidant capacities in extracts from six different varieties of sorghum grain and (b) investigate whether these PP extracts exhibit any protective effects on human neuroblastoma (BE(2)-M17) cells against Aβ- and tau-induced toxicity, Aβ aggregation, mitochondrial dysfunction, and reactive oxygen species (ROS) induced by Aβ and tert-butyl hydroperoxide (TBHP). PP and antioxidant capacity were quantified using chemical assays. Aβ- and tau-induced toxicity was determined using the 3-(4,5-dimenthylthiazol-2-yl)-2,5-dimethyltetrazolium bromide (MTS) assay. The thioflavin T (Th-T) assay assessed anti-Aβ aggregation. The dichlorodihydrofluorescein diacetate (DCFDA) assay determined the levels of general ROS and the MitoSOX assay determined the levels of mitochondrial superoxide. Sorghum varieties Shawaya short black-1 and IS1311C possessed the highest levels of total phenolics, total flavonoids, and antioxidant capacity, and sorghum varieties differed significantly in their profile of individual PPs. All extracts significantly increased cell viability compared to the control (minus extract). Variety QL33 (at 2000 µg sorghum flour equivalents/mL) showed the strongest protective effect with a 28% reduction in Aβ-toxicity cell death. The extracts of all sorghum varieties significantly reduced Aβ aggregation. All extracts except that from variety B923296 demonstrated a significant (p ≤ 0.05) downregulation of Aβ-induced and TBHP-induced ROS and mitochondrial superoxide relative to the control (minus extract) in a dose- and variety-dependent manner. We have demonstrated for the first time that sorghum polyphenolic extracts show promising neuroprotective effects against AD, which indicates the potential of sorghum foods to exert a similar beneficial property in the human diet. However, further analysis in other cellular models and in vivo is needed to confirm these effects.

Insights into the Neuroprotective Potential of Epicatechin: Effects against Aβ-Induced Toxicity in Caenorhabditis elegans

Medical therapies to avoid the progression of Alzheimer's disease (AD) are limited to date. Certain diets have been associated with a lower incidence of neurodegenerative diseases. In particular, the regular intake of foods rich in polyphenols, such as epicatechin (EC), could help prevent or mitigate AD progression. This work aims to explore the neuroprotective effects of EC using different transgenic strains of Caenorhabditis elegans, which express human Aβ1-42 peptides and contribute to elucidating the mechanisms involved in the effects of EC in AD. The performed assays indicate that this flavan-3-ol was able to reduce the signs of β-amyloid accumulation in C. elegans, improving motility and chemotaxis and increasing survival in transgenic strain peptide producers compared to nematodes not treated with EC. The neuroprotective effects exhibited by EC in C. elegans could be explained by the modulation of inflammation and stress-associated genes, as well as autophagy, microgliosis, and heat shock signaling pathways, involving the regulation of cpr-5, epg-8, ced-7, ZC239.12, and hsp-16 genes. Overall, the results obtained in this study support the protective effects of epicatechin against Aβ-induced toxicity.

Neuroprotective Mechanisms of Salidroside in Alzheimer's Disease: A Systematic Review and Meta-analysis of Preclinical Studies

Alzheimer's disease (AD) is a neurodegenerative disease of the central nervous system that occurs in old age and pre-aging, characterized by progressive cognitive dysfunction and behavioral impairment. Salidroside (Sal) is a phenylpropanoid mainly isolated from Rhodiola species with various pharmacological effects. However, the exact anti-AD mechanism of Sal has not been clearly elucidated. This meta-analysis aims to investigate the possible mechanisms by which Sal exerts its anti-AD effects by evaluating behavioral indicators and biochemical characteristics. A total of 20 studies were included, and the results showed that the Sal treatment significantly improved behavior abnormalities in AD animal models. With regard to neurobiochemical indicators, Sal treatment could effectively increase the antioxidant enzyme superoxide dismutase, decrease the oxidative stress indicator malondialdehyde, and decrease the inflammatory indicators interleukin 1β, interleukin 6, and tumor necrosis factor α. Sal treatment was effective in reducing neuropathological indicators, such as amyloid-β levels and the number of apoptotic cells. When the relevant literature on the treatment of rodent AD models is combined with Sal, the therapeutic potential of Sal through multiple mechanisms was confirmed. However, further confirmation by higher quality studies, larger sample sizes, and more comprehensive outcome evaluations in clinical trials is needed in the future.

Comprehensive evaluation of nutritional components, bioactive metabolites, and antioxidant activities in diverse sorghum (Sorghum bicolor (L.) Moench) landraces

Sorghum, one of the prospective crops for addressing future food and nutrition security, has received attention in recent years due to its health-promoting compounds. It is known that several environmental and genetic factors affect the metabolite contents of dietary crops. This study investigated the diversity of different nutrients, functional metabolites, and antioxidant activity using three different assays in 53 sorghum landraces from Korea, China, Japan, Ethiopia, and South Africa. The effects of origin and seed color variations were also investigated. Total phenolic (TPC), total tannin (TTC), total fat, total protein, total dietary fiber, and total crude fiber contents all varied significantly among the sorghum landraces (p < 0.05). Using a gas chromatography-flame ionization detector, palmitic, stearic, oleic, linoleic, and linolenic acids were detected in all the sorghum landraces, and their content significantly varied (p < 0.05). Furthermore, four 3-deoxyanthocyanidins (luteolinidin, apigeninidin, 5-methoxyluteolinidin, and 7-methoxyapigeninidin) and two flavonoids (luteolin and apigenin) were detected in most of the landraces using liquid chromatography-tandem mass spectrometry, and their concentrations also significantly varied. Statistical analyses supported by multivariate tools demonstrated that seed color variation had a significant effect on TPC, TTC, DPPH• and ABTS•+ scavenging activities, and ferric-reducing antioxidant power, with yellow landraces having the highest and white landraces having the lowest values. Seed color variation also had a significant effect on dietary fiber, linoleic acid, linolenic acid, and luteolin contents. In contrast, all nutritional components and fatty acids except total protein and oleic acid were significantly affected by origin, while most 3-deoxyanthocyanidins and flavonoids were unaffected by both origin and seed color differences. This is the first study to report the effect of origin on sorghum seed metabolites and antioxidant activities, laying the groundwork for future studies. Moreover, this study identified superior landraces that could be good sources of health-promoting metabolites.

Exploring the potentials of sorghum genotypes: a comprehensive study on nutritional qualities, functional metabolites, and antioxidant capacities

Introduction

Sorghum, long regarded as one of the most underutilized crops, has received attention in recent years. As a result, conducting multidisciplinary studies on the potential and health benefits of sorghum resources is vital if they are to be fully exploited. In this study, the nutritional contents, functional metabolites, and antioxidant capacities of 23 sorghum breeding lines and three popular cultivars were assessed.

Materials and method

All of the sorghum genotypes were grown under the same conditions, and mature seeds were hand-harvested. The metabolite contents and antioxidant capacities of sorghum seeds were assessed using standard protocols. Fatty acids were quantified using a gas chromatography-flame ionization detector, whereas flavonoids and 3-deoxyanthocyanidins were analyzed using a liquid chromatography-tandem mass spectrometry method. The data were analyzed using both univariate and multivariate statistical approaches.

Results and discussion

Total protein (9.05-14.61%), total fat (2.99-6.91%), crude fiber (0.71-2.62%), dietary fiber (6.72-16.27%), total phenolic (0.92-10.38 mg GAE/g), and total tannin (0.68-434.22 mg CE/g) contents varied significantly across the sorghum genotypes (p < 0.05). Antioxidant capacity, measured using three assays, also differed significantly. Five fatty acids, including palmitic, stearic, oleic, linoleic, and linolenic acids, were found in all the sorghum genotypes with statistically different contents (p < 0.05). Furthermore, the majority of the sorghum genotypes contained four 3-deoxyanthocyanidins, including luteolinidin, apigeninidin, 5-methoxyluteolinidin, and 7-methoxyapigeninidin, as well as two dominant flavonoids, luteolin and apigenin. Compared to the cultivars, some breeding lines had significantly high levels of metabolites and antioxidant activities. On the other hand, statistical analysis showed that total tannin, total phenolic, and antioxidant capacities varied significantly across white, yellow, and orange genotypes. Principal component analysis was used to differentiate the sorghum genotypes based on seed color and antioxidant index levels. Pearson's correlation analysis revealed strong links between biosynthetically related metabolites and those with synergistic antioxidant properties.

Conclusion

This research demonstrated the diversity of the sorghum resources investigated. Those genotypes with high levels of nutritional components, functional metabolites, and antioxidant activities could be used for consumption and breeding programs.

A review of the application of three-dimensional convolutional neural networks for the diagnosis of Alzheimer's disease using neuroimaging

Alzheimer's disease (AD) is a degenerative disorder that leads to progressive, irreversible cognitive decline. To obtain an accurate and timely diagnosis and detect AD at an early stage, numerous approaches based on convolutional neural networks (CNNs) using neuroimaging data have been proposed. Because 3D CNNs can extract more spatial discrimination information than 2D CNNs, they have emerged as a promising research direction in the diagnosis of AD. The aim of this article is to present the current state of the art in the diagnosis of AD using 3D CNN models and neuroimaging modalities, focusing on the 3D CNN architectures and classification methods used, and to highlight potential future research topics. To give the reader a better overview of the content mentioned in this review, we briefly introduce the commonly used imaging datasets and the fundamentals of CNN architectures. Then we carefully analyzed the existing studies on AD diagnosis, which are divided into two levels according to their inputs: 3D subject-level CNNs and 3D patch-level CNNs, highlighting their contributions and significance in the field. In addition, this review discusses the key findings and challenges from the studies and highlights the lessons learned as a roadmap for future research. Finally, we summarize the paper by presenting some major findings, identifying open research challenges, and pointing out future research directions.

Oxidative Stress in Tauopathies: From Cause to Therapy

Oxidative stress (OS) is the result of an imbalance between the production of reactive oxygen species (ROS) and the antioxidant capacity of cells. Due to its high oxygen demand, the human brain is highly susceptible to OS and, thus, it is not a surprise that OS has emerged as an essential component of the pathophysiology of several neurodegenerative diseases, including tauopathies. Tauopathies are a heterogeneous group of age-related neurodegenerative disorders characterized by the deposition of abnormal tau protein in the affected neurons. With the worldwide population aging, the prevalence of tauopathies is increasing, but effective therapies have not yet been developed. Since OS seems to play a key role in tauopathies, it has been proposed that the use of antioxidants might be beneficial for tau-related neurodegenerative diseases. Although antioxidant therapies looked promising in preclinical studies performed in cellular and animal models, the antioxidant clinical trials performed in tauopathy patients have been disappointing. To develop effective antioxidant therapies, the molecular mechanisms underlying OS in tauopathies should be completely understood. Here, we review the link between OS and tauopathies, emphasizing the causes of OS in these diseases and the role of OS in tau pathogenesis. We also summarize the antioxidant therapies proposed as a potential treatment for tauopathies and discuss why they have not been completely translated to clinical trials. This review aims to provide an integrated perspective of the role of OS and antioxidant therapies in tauopathies. In doing so, we hope to enable a more comprehensive understanding of OS in tauopathies that will positively impact future studies.

Role of Polyphenol-Derived Phenolic Acid in Mitigation of Inflammasome-Mediated Anxiety and Depression

Overexposure to mental stress throughout life is a significant risk factor for the development of neuropsychiatric disorders, including depression and anxiety. The immune system can initiate a physiological response, releasing stress hormones and pro-inflammatory cytokines, in response to stressors. These effects can overcome allostatic physiological mechanisms and generate a pro-inflammatory environment with deleterious effects if occurring chronically. Previous studies in our lab have identified key anti-inflammatory properties of a bioavailable polyphenolic preparation BDPP and its ability to mitigate stress responses via the attenuation of NLRP3 inflammasome-dependent responses. Inflammasome activation is part of the first line of defense against stimuli of different natures, provides a rapid response, and, therefore, is of capital importance within the innate immunity response. malvidin-3-O-glucoside (MG), a natural anthocyanin present in high proportions in grapes, has been reported to exhibit anti-inflammatory effects, but its mechanisms remain poorly understood. This study aims to elucidate the therapeutic potential of MG on inflammasome-induced inflammation in vitro and in a mouse model of chronic unpredictable stress (CUS). Here, it is shown that MG is an anti-pyroptotic phenolic metabolite that targets NLRP3, NLRC4, and AIM2 inflammasomes, subsequently reducing caspase-1 and IL-1β protein levels in murine primary cortical microglia and the brain, as its beneficial effect to counteract anxiety and depression is also demonstrated. The present study supports the role of MG to mitigate bacterial-mediated inflammation (lipopolysaccharide or LPS) in vitro and CUS-induced behavior impairment in vivo to address stress-induced inflammasome-mediated innate response.

Deer antler extracts reduce amyloid-beta toxicity in a Caenorhabditis elegans model of Alzheimer's disease

ETHNOPHARMACOLOGICAL RELEVANCE

Velvet antler extracts (VAE) are composed of a variety of active substances and growth factors, and have been reported to improve sleep quality and memory.

AIM OF THE STUDY

We aimed to explore the protective effects and mechanism of action for VAE on Alzheimer's disease (AD) using a transgenic Caenorhabditis elegans model.

MATERIALS AND METHODS

C. elegans were cultivated at 40% relative humidity on solid nematode growth medium (NGM) containing live E. coli (OP50) as the food source, with Strain N2 (normal) held at 20 °C and the CL4176s (transgenic) held at 16 °C. AD-like aggregation of Aβ peptide in the CL4176s strain is induced by lifting the temperature to 25 °C. Nematodes were treated with three types of VAEs and Resveratrol (positive control). Analyses included qRT-PCR for quantification of gene transcripts of interest; ELISA for measuring levels of amyloid-β protein; Thioflavin T fluorescent staining for localizing Aβ depositions; assays for reactive oxygen species (ROS) and superoxide dismutase activity (SOD).

RESULTS

VAEs reduced β-amyloid peptide (Aβ) toxicity in the transgenic C. elegans model. An enzymatically-digested VAE (EDVAE) was superior to both a cold-water VAE (CWVAE) and a hot-water VAE (HWVAE) from the same velvet antler. EDVAE treatment reduced the severity of the Aβ-induced paralysis phenotype and decreased the amount of Aβ deposits in the AD model nematodes, and these effects were found to be significantly better than that of the positive control Resveratrol. In addition, EDVAE treatment reduced production of ROS (induced by Aβ), enhanced SOD activity, and elevated expression levels of antioxidant-related transcription factors, although it is not known whether these effects were achieved directly or indirectly.

CONCLUSION

EDVAE had a protective role in Aβ-induced toxicity in the transgenic AD nematodes, possibly through reducing accumulation of toxic Aβ and enhancing the ability of nematodes to resist oxidative stress. Thus, EDVAE has potential to be an effective treatment to relieve the symptoms of AD.