Sesamol supplementation prevents systemic inflammation-induced memory impairment and amyloidogenesis via inhibition of nuclear factor kappaB

Sesamol as a potent anticancer compound: from chemistry to cellular interactions

Sesamol (SM), a well-known component isolated from sesame seeds (Sesamum indicum), used in traditional medicines in treating numerous ailments. However, numerous molecular investigations revealed the various mechanisms behind its activity, emphasizing its antiproliferative, anti-inflammatory, and apoptosis-inducing properties, preventing cancer cell spread to distant organs. In several cells derived from various malignant tissues, SM-regulated signal transduction pathways and cellular targets have been identified. This review paper comprehensively describes the anticancer properties of SM and SM-viable anticancer drugs. Additionally, the interactions of this natural substance with standard anticancer drugs are examined, and the benefits of using nanotechnology in SM applications are explored. This makes SM a prime example of how ethnopharmacological knowledge can be applied to the development of contemporary drugs.

Intervention effects of low-molecular-weight chondroitin sulfate from the nasal cartilage of yellow cattle on lipopolysaccharide-induced behavioral disorders: regulation of the microbiome-gut-brain axis

Chondroitin sulfate (CS) is a sulfated linear polysaccharide with different functional activities, including antioxidant, anti-inflammatory, lipid-lowering, and immune regulation. As natural sulfated polysaccharides have high molecular weight, high apparent viscosity, low water solubility, complex structure, and high negative charge, they have difficulty binding to receptors within cells across tissue barriers, resulting in low bioavailability and unclear structure-activity relationships. In this study, an H2O2-Vc oxidative degradation system was employed to perform environmentally friendly and controllable degradation of CS extracted from the nasal cartilage of Shaanxi Yellow cattle. Two low-molecular-weight chondroitin sulfates (LMWCSs), CS-1 (14.8 kDa) and CS-2 (50.9 kDa), that exhibit strong in vitro free radical scavenging ability were obtained, and their structures were characterized. Mice intraperitoneally administered lipopolysaccharide (LPS) were used to explore the cognitive intervention effects of LMWCS. Supplementing CS-1 and CS-2 significantly downregulated the levels of the serum inflammatory factors, TNF-α and IL-1β, promoted the expression of GSH in the brain, and inhibited the production of the lipid peroxidation product, malondialdehyde (MDA), ultimately inhibiting LPS-induced cognitive impairment in mice. Surprisingly, compared to the LPS model group, the abundances of Streptococcus, Eisenbergiella, Vampirovibrio, Coprococcus, Enterococcus and Lachnoanaerobaculum were significantly increased in the intestines of mice in the CS-1 and CS-2 group, whereas those of Parabacteroides and Mycoplasma were significantly decreased. Altogether, this study provides a theoretical basis for the comprehensive utilization of agricultural and animal resources and the application of brain nutrition, anti-inflammatory, and LMWCS health products.

What Threshold of Amyloid Reduction Is Necessary to Meaningfully Improve Cognitive Function in Transgenic Alzheimer's Disease Mice?

Background

Amyloid-β plaques (Aβ) are associated with Alzheimer's disease (AD). Pooled assessment of amyloid reduction in transgenic AD mice is critical for expediting anti-amyloid AD therapeutic research.

Objective

The mean threshold of Aβ reduction necessary to achieve cognitive improvement was measured via pooled assessment (n = 594 mice) of Morris water maze (MWM) escape latency of transgenic AD mice treated with substances intended to reduce Aβ via reduction of beta-secretase cleaving enzyme (BACE).

Methods

Machine learning and statistical methods identified necessary amyloid reduction levels using mouse data (e.g., APP/PS1, LPS, Tg2576, 3xTg-AD, control, wild type, treated, untreated) curated from 22 published studies.

Results

K-means clustering identified 4 clusters that primarily corresponded with level of Aβ: untreated transgenic AD control mice, wild type mice, and two clusters of transgenic AD mice treated with BACE inhibitors that had either an average 25% "medium reduction" of Aβ or 50% "high reduction" of Aβ compared to untreated control. A 25% Aβ reduction achieved a 28% cognitive improvement, and a 50% Aβ reduction resulted in a significant 32% improvement compared to untreated transgenic mice (p < 0.05). Comparatively, wild type mice had a mean 41% MWM latency improvement over untreated transgenic mice (p < 0.05). BACE reduction had a lesser impact on the ratio of Aβ42 to Aβ40. Supervised learning with an 80% -20% train-test split confirmed Aβ reduction was a key feature for predicting MWM escape latency (R2 = 0.8 to 0.95).

Conclusions

Results suggest a 25% reduction in Aβ as a meaningful treatment threshold for improving transgenic AD mouse cognition.

Sesamol Mitigates Chronic Iron Overload-Induced Cognitive Impairment and Systemic Inflammation via IL-6 and DMT1 Regulation

SCOPE

Excessive iron contributes to oxidative damage and cognitive decline in Alzheimer's disease. Sesamol, a compound in sesame oil that exhibits both anti-inflammatory and neuroprotective properties, is examined in this study for its ability to alleviate cognitive impairments in iron overload mice model.

METHODS AND RESULTS

An iron overload model is established by intraperitoneally injecting dextran iron (250 mg kg-1 body weight) twice a week for 6 weeks, while sesamol (100 mg kg-1 body weight) is administered daily for the same length of time. The results demonstrate that sesamol protects spatial working memory and learning ability in iron overload mice, and inhibits neuronal loss and brain atrophy induced by iron overload. Moreover, sesamol significantly decreases interleukin-6 and malondialdehyde, and increases glutathione peroxidase 4 in the brains of iron overload mice. Additionally, sesamol maintains iron homeostasis in the brain by regulating the expressions of transferrin receptors, divalent metal transporter 1, and hepcidin, and reducing iron accumulation. Furthermore, sesamol suppresses disturbed systemic iron homeostasis and inflammation, particularly liver interleukin-6 expression.

CONCLUSION

These findings suggest that sesamol may be effective in mitigating neuroinflammatory responses and cognitive impairments induced by iron overload, potentially through its involvement in mediating the liver-brain axis.

The protective effects of sesamol and/or the probiotic, Lactobacillus rhamnosus, against aluminum chloride-induced neurotoxicity and hepatotoxicity in rats: Modulation of Wnt/β-catenin/GSK-3β, JAK-2/STAT-3, PPAR-γ, inflammatory, and apoptotic pathways

Introduction: Aluminium (Al) is accumulated in the brain causing neurotoxicity and neurodegenerative disease like Alzheimer's disease (AD), multiple sclerosis, autism and epilepsy. Hence, attenuation of Al-induced neurotoxicity has become a "hot topic" in looking for an intervention that slow down the progression of neurodegenerative diseases. Objective: Our study aims to introduce a new strategy for hampering aluminum chloride (AlCl3)-induced neurotoxicity using a combination of sesamol with the probiotic bacteria; Lactobacillus rhamnosus (L. rhamnosus) and also to test their possible ameliorative effects on AlCl3-induced hepatotoxicity. Methods: Sprague-Dawley male rats were randomly divided into five groups (n = 10/group) which are control, AlCl3, AlCl3 + Sesamol, AlCl3 + L. rhamnosus and AlCl3 + Sesamol + L. rhamnosus. We surveilled the behavioral, biochemical, and histopathological alterations centrally in the brain and peripherally in liver. Results: This work revealed that the combined therapy of sesamol and L. rhamnosus produced marked reduction in brain amyloid-β, p-tau, GSK-3β, inflammatory and apoptotic biomarkers, along with marked elevation in brain free β-catenin and Wnt3a, compared to AlCl3-intoxicated rats. Also, the combined therapy exerted pronounced reduction in hepatic expressions of JAK-2/STAT-3, inflammatory (TNF-α, IL-6, NF-κB), fibrotic (MMP-2, TIMP-1, α-SMA) and apoptotic markers, (caspase-3), together with marked elevation in hepatic PPAR-γ expression, compared to AlCl3 -intoxicated rats. Behavioral and histopathological assessments substantiated the efficiency of this combined regimen in halting the effect of neurotoxicity. Discussion: Probiotics can be used as an add-on therapy with sesamol ameliorate AlCl3 -mediated neurotoxicity and hepatotoxicity.

Lignan-Rich Sesame (Sesamum indicum L.) Cultivar Exhibits In Vitro Anti-Cholinesterase Activity, Anti-Neurotoxicity in Amyloid-β Induced SH-SY5Y Cells, and Produces an In Vivo Nootropic Effect in Scopolamine-Induced Memory Impaired Mice

Alzheimer's disease, a major cause of dementia, is characterized by impaired cholinergic function, increased oxidative stress, and amyloid cascade induction. Sesame lignans have attracted considerable attention owing to their beneficial effects on brain health. This study investigated the neuroprotective potential of lignan-rich sesame cultivars. Among the 10 sesame varieties studied, Milyang 74 (M74) extracts exhibited the highest total lignan content (17.71 mg/g) and in vitro acetylcholinesterase (AChE) inhibitory activity (66.17%, 0.4 mg/mL). M74 extracts were the most effective in improving cell viability and inhibiting reactive oxygen species (ROS) and malondialdehyde (MDA) generation in amyloid-β_25-35 fragment-treated SH-SY5Y cells. Thus, M74 was used to evaluate the nootropic effects of sesame extracts and oil on scopolamine (2 mg/kg)-induced memory impairment in mice compared to the control cultivar (Goenback). Pretreatment with the M74 extract (250 and 500 mg/kg) and oil (1 and 2 mL/kg) effectively improved memory disorder in mice (demonstrated by the passive avoidance test), inhibited AChE, and enhanced acetylcholine (Ach) levels. Moreover, immunohistochemistry and Western blot results showed that the M74 extract and oil reversed the scopolamine-induced increase in APP, BACE-1, and presenilin expression levels in the amyloid cascade and decreased BDNF and NGF expression levels in neuronal regeneration.

Formulation Strategies for Enhancing Pharmaceutical and Nutraceutical Potential of Sesamol: A Natural Phenolic Bioactive

Natural plants and their products continue to be the major source of phytoconstituents in food and therapeutics. Scientific studies have evidenced the benefits of sesame oil and its bioactives in various health conditions. Various bioactives present in it include sesamin, sasamolin, sesaminol, and sesamol; among these, sesamol represents a major constituent. This bioactive is responsible for preventing various diseases including cancer, hepatic disorders, cardiac ailments, and neurological diseases. In the last decade, the application of sesamol in the management of various disorders has attracted the increasing interest of the research community. Owing to its prominent pharmacological activities, such as antioxidant, antiinflammatory, antineoplastic, and antimicrobial, sesamol has been explored for the above-mentioned disorders. However, despite the above-mentioned therapeutic potential, its clinical utility is mainly hindered owing to low solubility, stability, bioavailability, and rapid clearance issues. In this regard, numerous strategies have been explored to surpass these restrictions with the formulation of novel carrier platforms. This review aims to describe the various reports and summarize the different pharmacological activities of sesamol. Furthermore, one part of this review is devoted to formulating strategies to improve sesamol's challenges. To resolve the issues such as the stability, low bioavailability, and high systemic clearance of sesamol, novel carrier systems have been developed to open a new avenue to utilize this bioactive as an efficient first-line treatment for various diseases.

Sesamol Attenuates Scopolamine-Induced Cholinergic Disorders, Neuroinflammation, and Cognitive Deficits in Mice

Alzheimer's disease (AD) is a neurodegenerative disease, characterized by memory loss and cognitive deficits accompanied by neuronal damage and cholinergic disorders. Sesamol, a lignan component in sesame oil, has been proven to have neuroprotective effects. This research aimed to investigate the preventive effects of sesamol on scopolamine (SCOP)-induced cholinergic disorders in C57BL/6 mice. The mice were pretreated with sesamol (100 mg/kg/d, p.o.) for 30 days. Behavioral tests indicated that sesamol supplement prevented SCOP-induced cognitive deficits. Sesamol enhanced the expression of neurotrophic factors and postsynaptic density (PSD) in SCOP-treated mice, reversing neuronal damage and synaptic dysfunction. Importantly, sesamol could balance the cholinergic system by suppressing the AChE activity and increasing the ChAT activity and M1 mAChR expression. Sesamol treatment also inhibited the expression of inflammatory factors and overactivation of microglia in SCOP-treated mice. Meanwhile, sesamol improved the antioxidant enzyme activity and suppressed oxidative stress in SCOP-treated mice and ameliorated the oxidized cellular status and mitochondrial dysfunction in SCOP-treated SH-SY5Y cells. In conclusion, these results indicated that sesamol attenuated SCOP-induced cognitive dysfunction via balancing the cholinergic system and reducing neuroinflammation and oxidative stress.

Preventive effects of arctigenin from Arctium lappa L against LPS-induced neuroinflammation and cognitive impairments in mice

Arctigenin (Arc) is a phenylpropanoid dibenzylbutyrolactone lignan in Arctium lappa L, which has been widely applied as a traditional Chinese herbal medicine for treating inflammation. In the present study, we explored the neuroprotective effect and the potential mechanisms of arctigenin against LPS-evoked neuroinflammation, neurodegeneration, and memory impairments in the mice hippocampus. Daily administration of arctigenin (50 mg/kg per day, i.g.) for 28 days revealed noticeable improvements in spatial learning and memory deficits after exposure to LPS treatment. Arctigenin prevented LPS-induced neuronal/synaptic injury and inhibited the increases in Abeta (Aβ) generation and the levels of amyloid precursor protein (APP) and β-site amyloid precursor protein cleavage enzyme 1 (BACE1). Moreover, arctigenin treatment also suppressed glial activation and reduced the production of proinflammatory cytokines. In LPS-treated BV-2 microglial cells and mice, activation of the TLR4 mediated NF-κB signaling pathway was significantly suppressed by arctigenin administration. Mechanistically, arctigenin reduced the LPS-induced interaction of adiponectin receptor 1 (AdipoR1) with TLR4 and its coreceptor CD14 and inhibited the TLR4-mediated downstream inflammatory response. The outcomes of the current study indicate that arctigenin mitigates LPS-induced apoptotic neurodegeneration, amyloidogenesis and neuroinflammation as well as cognitive impairments, and suggest that arctigenin may be a potential therapeutic candidate for neuroinflammation/neurodegeneration-related diseases.

Effect of Immune Stress on Growth Performance and Immune Functions of Livestock: Mechanisms and Prevention

Simple Summary

Immune stress is an important stressor in domestic animals that leads to decreased feed intake, slow growth, and reduced disease resistance of pigs and poultry. Especially in high-density animal feeding conditions, the risk factor of immune stress is extremely high, as they are easily harmed by pathogens, and frequent vaccinations are required to enhance the immunity function of the animals. This review mainly describes the causes, mechanisms of immune stress and its prevention and treatment measures. This provides a theoretical basis for further research and development of safe and efficient prevention and control measures for immune stress in animals.

Abstract

Immune stress markedly affects the immune function and growth performance of livestock, including poultry, resulting in financial loss to farmers. It can lead to decreased feed intake, reduced growth, and intestinal disorders. Studies have shown that pathogen-induced immune stress is mostly related to TLR4-related inflammatory signal pathway activation, excessive inflammatory cytokine release, oxidative stress, hormonal disorders, cell apoptosis, and intestinal microbial disorders. This paper reviews the occurrence of immune stress in livestock, its impact on immune function and growth performance, and strategies for immune stress prevention.

Targeting NF-κB pathway by dietary lignans in inflammation: expanding roles of gut microbiota and metabolites

Inflammation is a major factor affecting human health. Nuclear factor-kappa B (NF-κB) plays a vital role in the development of inflammation, and the promoters of most inflammatory cytokine genes have NF-κB-binding sites. Targeting NF-κB could be an exciting route for the prevention and treatment of inflammatory diseases. As important constituents of natural plants, lignans are proved to have numerous biological functions. There are growing pieces of evidence demonstrate that lignans have the potential anti-inflammatory activities. In this work, the type, structure and source of lignans and the influence on mitigating the inflammation are systematically summarized. This review focuses on the targeting NF-κB signaling pathway in the inflammatory response by different lignans and their molecular mechanisms. Lignans also regulate gut microflora and change gut microbial metabolites, which exert novel pathway to prevent NF-κB activation. Taken together, lignans target NF-κB with various mechanisms to inhibit inflammatory cytokine expressions in the inflammatory response. It will provide a scientific theoretical basis for further research on the anti-inflammatory effects of lignans and the development of functional foods.

Sesamol Ameliorates Dextran Sulfate Sodium-induced Depression-like and Anxiety-like Behaviors in Colitis Mice：The potential involvement of Gut-Brain Axis

Inflammatory bowel disease (IBD) is accompanied by some psychiatric disorders, including anxiety and depression. Sesamol has been reported to alleviate colitis symptoms and depression-like behaviors caused by chronic unpredictable mild...

Sesamol Attenuates Amyloid Peptide Accumulation and Cognitive Deficits in APP/PS1 Mice: The Mediating Role of the Gut-Brain Axis

Alzheimer's disease (AD), a neurodegenerative disease, is the leading cause of dementia. Sesamol is a lignan extracted from sesame oil and has been found to exert neuroprotective effects. The present study aimed to investigate the neuroprotective effects of sesamol on APPswe/PS1dE9 transgenic AD mice. The AD mice were fed with a diet supplemented with sesamol (0.075 w/w %). Sesamol treatment improved spatial memory and learning ability in AD mice, improved neuronal damage, and decreased Aβ accumulation. Sesamol protected the synaptic ultrastructure and inhibited neuroinflammatory responses in the brain of AD mice. Sesamol also significantly inhibited the overactivated microglia and reduced the overexpression of TNF-α and IL-1β in the brain of AD mice. Notably, sesamol reshaped gut microbiota by significantly decreasing the relative abundance of Helicobacter hepaticus, Clostridium, and Bacillaceae, enhancing the relative abundance of Rikenellaceae and Bifidobacterium in AD mice. It has been found that sesamol protected the gut barrier integrity and prevented the LPS leakage into the serum. Importantly, sesamol remarkably enhanced the content of SCFAs, including acetate, propionate, isobutyrate, butyrate, and valerate, in AD mice. Correlation analysis indicated that there was a strong correlation between the levels of SCFAs and cognitive functions. These results demonstrated that sesamol attenuated AD-related cognitive dysfunction and neuroinflammatory responses, which could be partly explained by its role in mediating the gut microbe-SCFA-brain axis. Thus, sesamol is a promising nutritional intervention strategy to prevent AD via the microbiota-gut-brain axis.

Neuroprotective effect of sesamol against aluminum nanoparticle-induced toxicity in rats

Alumina nanoparticles (ALNPs) are widely used causing neurobehavioral impairment in intoxicated animals and humans. Sesamol (SML) emerged as a natural phytochemical with potent antioxidant and anti-inflammatory properties. However, no study has directly tested the potential of SML to protect against AlNP-induced detrimental effects on the brain. AlNPs (100 mg/kg) were orally administered to rats by gavage with or without oral sesamol (100 mg/kg) for 28 days. In AlNP-intoxicated group, the brain AChE activity was elevated. The concentrations of MDA and 8-OHdG were increased suggesting lipid peroxidation and oxidative DNA damage. GSH depletion with inhibited activities of CAT and SOD were demonstrated. Serum levels of IL-1β and IL-6 were elevated. The expressions of GST, TNF-α, and caspase-3 genes in the brain were upregulated. Histopathologically, AlNPs induced hemorrhages, edema, neuronal necrosis, and/or apoptosis in medulla oblongata. The cerebellum showed loss of Purkinje cells, and the cerebrum showed perivascular edema, neuronal degeneration, necrosis, and neuronal apoptosis. However, concomitant administration of SML with AlNPs significantly ameliorated the toxic effects on the brain, reflecting antioxidant, anti-inflammatory, and anti-apoptotic effects of SML. Considering these results, sesamol could be a promising phytochemical with neuroprotective activity against AlNP-induced neurotoxicity.

In Silico Analysis to Link Insulin Resistance, Obesity and Ageing with Alzheimer's Disease

The process of ageing accompanies several metabolic diseases. With ageing, fats accumulate to increase the visceral and abdominal adiposity leading to hyperinsulinemia, insulin resistance, obesity and several other diseases. Drosophila melanogaster is often used to study the ageing process and its related disorders. Therefore, in this study, we performed an in silico analysis to relate the process of ageing and insulin resistance. We analysed the data of insulin-resistant Drosophila from the GEO database and compared it with the data from the literature survey. We observed that 98 genes were common in both the models, and they showed gene modulations related to metabolic pathways, fatty acid metabolism, insulin resistance and neural receptor-ligand binding pathways. Analysis of the REACTOME database against human data revealed that the TRKB signalling pathway is commonly affected. The TRKB-mediated BDNF pathway is a major regulator of memory loss. We further analysed the common genes in Alzheimer's disease and compared the fly data with human data to identify the diseases related to these common genes. Then, we performed a literature survey to provide protective mechanisms for the TRKB signalling pathway activation, mediated through polyphenols. We treated the flies with sesamol-conjugated lipoic acid derivative (a phenolic compound) at hormetic doses to evaluate its effect on the memory of flies.

Evaluation of Anti-inflammatory Nutraceuticals in LPS-induced Mouse Neuroinflammation Model: An Update

It is known that peripheral infections, accompanied by inflammation, represent significant risk factors for the development of neurological disorders by modifying brain development or affecting normal brain aging. The acute effects of systemic inflammation on progressive and persistent brain damage and cognitive impairment are well documented. Anti-inflammatory therapies may have beneficial effects on the brain, and the protective properties of a wide range of synthetic and natural compounds have been extensively explored in recent years. In our previous review, we provided an extensive analysis of one of the most important and widely-used animal models of peripherally induced neuroinflammation and neurodegeneration - lipopolysaccharide (LPS)-treated mice. We addressed the data reproducibility in published research and summarized basic features and data on the therapeutic potential of various natural products, nutraceuticals, with known anti-inflammatory effects, for reducing neuroinflammation in this model. Here, recent data on the suitability of the LPS-induced murine neuroinflammation model for preclinical assessment of a large number of nutraceuticals belonging to different groups of natural products such as flavonoids, terpenes, non-flavonoid polyphenols, glycosides, heterocyclic compounds, organic acids, organosulfur compounds and xanthophylls, are summarized. Also, the proposed mechanisms of action of these molecules are discussed.

Sesamol promotes browning of white adipocytes to ameliorate obesity by inducing mitochondrial biogenesis and inhibition mitophagy via β3-AR/PKA signaling pathway

Background

Obesity is defined as an imbalance between energy intake and expenditure, and it is a serious risk factor of non-communicable diseases. Recently many studies have shown that promoting browning of white adipose tissue (WAT) to increase energy consumption has a great therapeutic potential for obesity. Sesamol, a lignan from sesame oil, had shown potential beneficial functions on obesity treatment.

Objective

In this study, we used C57BL/6J mice and 3T3-L1 adipocytes to investigate the effects and the fundamental mechanisms of sesamol in enhancing the browning of white adipocytes to ameliorate obesity.

Methods

Sixteen-week-old C57BL/6J male mice were fed high-fat diet (HFD) for 8 weeks to establish the obesity models. Half of the obese mice were administered with sesamol (100 mg/kg body weight [b.w.]/day [d] by gavage for another 8 weeks. Triacylglycerol (TG) and total cholesterol assay kits were used to quantify serum TG and total cholesterol (TC). Oil red O staining was used to detect lipid droplet in vitro. Mito-Tracker Green was used to detect the mitochondrial content. Quantitative reverse transcription-polymerase chain reaction (RT-PCR) was used to detect the levels of beige-specific genes. Immunoblotting was used to detect the proteins involved in beige adipocytes formation.

Results

Sesamol decreased the content of body fat and suppressed lipid accumulation in HFD-induced obese mice. In addition, sesamol significantly upregulated uncoupling protein-1 (UCP1) protein in adipose tissue. Further research found that sesamol also significantly activated the browning program in mature 3T3-L1 adipocytes, manifested by the increase in beige-specific genes and proteins. Moreover, sesamol greatly increased mitochondrial biogenesis, as proved by the upregulated protein levels of mitochondrial biogenesis, and the inhibition of the proteins associated with mitophagy. Furthermore, β3-adrenergic receptor (β3-AR), protein kinase A-C (PKA-C) and Phospho-protein kinase A (p-PKA) substrate were elevated by sesamol, and these effects were abolished by the pretreatment of antagonists β3-AR.

Conclusion

Sesamol promoted browning of white adipocytes by inducing mitochondrial biogenesis and inhibiting mitophagy through the β3-AR/PKA pathway. This preclinical data promised the potential to consider sesamol as a metabolic modulator of HFD-induced obesity.

Sesamol alleviates chronic intermittent hypoxia-induced cognitive deficits via inhibiting oxidative stress and inflammation in rats

Chronic intermittent hypoxia (CIH) is a major pathophysiological feature of obstructive sleep apnea (OSA), which can cause oxidative stress and inflammation which can further impair the nervous system. Cognitive impairment is a common complication of the nervous system in OSA. Sesamol, a natural extract from Sesamum plants, is believed to have strong antioxidant and anti-inflammation capacity, which has a powerful neuroprotective function. But whether sesamol can improve CIH-induced cognitive impairment is unclear. This study aimed to explore whether sesamol can improve CIH-induced cognitive impairment and its relative mechanism in the model rats with OSA. Rats were exposed to CIH for 8 h a day for 2, 4, 6, and 8 weeks separately and concurrently were treated with sesamol (20 mg/kg/day, intraperitoneal). The Morris water maze (MWM) test was used to evaluate their learning and memory function. The activity of the superoxide dismutase (SOD) and the level of malondialdehyde were measured to evaluate the oxidative stress in the hippocampus of the rats. The levels of tumour necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β) in the hippocampus were quantified to analyse neuroinflammation by ELISA. The MWM test showed that sesamol improved learning and memory impairment in CIH-exposed rats. We also found that the sesamol-treated CIH-exposed rats had significantly increased the activity of SOD, as well as reduced the level of malondialdehyde in the hippocampus. In addition, sesamol also reduced the levels of TNF-α and IL-1β in the hippocampus. These data show that sesamol is able to alleviate cognitive impairments in CIH-exposed rats, with its neuroprotective effects likely inhibiting oxidative stress and inflammation.

Sesamol Supplementation Attenuates DSS-Induced Colitis via Mediating Gut Barrier Integrity, Inflammatory Responses, and Reshaping Gut Microbiome

Sesamol, a liposoluble lignan extract, has already been proved to possess potent anti-inflammatory properties, and it could also regulate gut dysfunction. The purpose of the present research is to explore the protective effect of sesamol on colitis mice. In the current research, sesamol treatment (100 mg/kg bodyweight/day) for 6 weeks inhibited the dextran sulphate sodium (DSS)-induced bodyweight loss of mice. Transmission electron microscopy and hematoxylin and eosin staining results showed that the DSS-induced histopathological changes of mice were also recovered by sesamol supplementation. In addition, DSS-induced inflammatory responses were inhibited by sesamol supplementation via the NF-κB signaling pathway in mice colon. Moreover, sesamol treatment prevented gut barrier damages by enhancing the expression of tight junction proteins (occludin, claudin-1, and ZO-1) and recovering the loss of gut mucus layer. Furthermore, sesamol supplementation also increased the short-chain fatty acid (SCFAs) contents of acetate, propionate, and butyrate. Furthermore, sesamol supplementation changed the gut microbiome structure by enhancing the relative abundance of Coprococcuscus, Butyricicoccus, Odoribacter, and AF12 in colitis mice. In conclusion, sesamol could effectively ameliorate DSS-induced colitis by promoting gut microecology.

Phenolic Glycosides from the Roots of Ficus hirta Vahl. and Their Antineuroinflammatory Activities

Ficus hirta Vahl. (Wuzhimaotao) is an edible functional food used for the soup cooking and health products. Seven undescribed phenolic glycosides (1-7), along with 20 analogues, were isolated from the roots of Ficus hirta. Their structures were determined by comprehensive spectroscopic methods (UV, IR, HRESIMS, and NMR), while the absolute configuration of 1 was established by comparison of the experimental and calculated ECD data. The antineuroinflammatory effects of all the compounds were examined by Western blot. Compounds 1 and 11 attenuated the phosphorylation of AKT, JNK, and ERK1/2. In addition, compound 11 inhibited the NF-κB p65 phosphorylation. Our results indicated that compounds 1 and 11 decreased the occurrence of neuroinflammation in BV2 microglia cells, which might be regulated by inhibiting the activity of proteins in NF-κB, MAPK (JNK and ERK1/2), or AKT signaling pathways. Thus, 1 and 11 might exhibit antineuroinflammatory activities and show promise in treating neurodegenerative diseases.

Protective Effects of Sesamol on Systemic Inflammation and Cognitive Impairment in Aging Mice

Sesamol, a lignan in sesame, possesses several bioactivities, such as antioxidation, anti-inflammation, and neuroprotective capability. In this study, the effects of sesamol on aging-caused cognitive defects are investigated. Twelve-month-old mice were treated with sesamol (0.1%, w/w) as dietary supplementation for 12 weeks. Behavioral tests revealed that sesamol improved aging-associated cognitive impairments. Sesamol decreased aging-induced oxidative stress via suppression of malondialdehyde production and increased antioxidant enzymes. Histological staining showed that sesamol treatment improved aging-induced neuronal damage and synaptic dysfunction in the hippocampus. Furthermore, sesamol significantly reduced aging-induced neuroinflammation by inhibiting the microglial overactivation and inflammatory cytokine expressions. Meanwhile, the accumulation of Aβ_1-42 was reduced by sesamol treatment. Moreover, sesamol protected the gut barrier integrity and reduced LPS release, which was highly associated with its beneficial effects on behavioral and inflammatory changes. In conclusion, our findings indicated that the use of sesamol is feasible in the treatment of aging-related diseases.

Geraniin Attenuates Lipopolysaccharide-Induced Cognitive Impairment in Mice by Inhibiting Toll-Like Receptor 4 Activation

Geraniin has been reported to possess potent anti-inflammatory properties and to modulate the macrophage polarization. This study sought to evaluate the protective effects and underlying mechanisms of geraniin on lipopolysaccharide (LPS)-induced neuroinflammation and neurobiological alternations as well as cognitive impairment. Daily intragastrical administration with geraniin (20 mg kg^-1 day^-1) for 14 days significantly prolonged the duration in the target quadrant (26.53 ± 2.03 versus 37.09 ± 3.27%; p < 0.05) and increased crossing-target number (1.93 ± 0.22 versus 3.08 ± 0.17; p < 0.01) in the probe test of LPS-treated mice. Geraniin also ameliorated LPS-elicited neural/synaptic impairments and decreased levels of LPS-induced Aβ generation (p < 0.05), amyloid precursor protein (APP) (p < 0.05) and β-site amyloid precursor protein cleavage enzyme 1 (BACE1) (p < 0.05). Furthermore, geraniin suppressed the production of pro-inflammatory cytokines, including tumor necrosis factor α (TNF-α) (9.85 ± 0.58 versus 5.20 ± 0.52 pg/mg of protein; p < 0.01), interleukin (IL)-1β (16.31 ± 0.67 versus 8.62 ± 0.46 pg/mg of protein; p < 0.01), and IL-6 (12.12 ± 0.45 versus 7.43 ± 0.32 pg/mg of protein; p < 0.05), and inhibited glial cell activation. Moreover, geraniin effectively polarized the microglia toward an anti-inflammatory M2 phenotype. Further study revealed that geraniin targeted toll-like receptor 4 (TLR4)-mediated signaling and decreased the production of pro-inflammatory cytokines in BV-2 microglial cells. These results indicate that geraniin mitigates LPS-elicited neural/synaptic neurodegeneration, amyloidogenesis, neuroinflammation, and cognitive impairment and suggest geraniin as a therapeutic option for neuroinflammation-associated neurological disorders, such as Alzheimer's disease.

Lycopene ameliorates systemic inflammation-induced synaptic dysfunction via improving insulin resistance and mitochondrial dysfunction in the liver-brain axis

Systemic inflammation is an important determinant of synaptic dysfunction, but the underlying molecular mechanisms remain elusive. Lycopene (LYC), a major carotenoid present in tomato, is regarded as a nutraceutical that has significant antioxidant and anti-obesity bioactivities. In the current study, we randomly divided 3-month-old C57BL/6J mice into 3 groups: the control, LPS and LPS + LYC groups (LYC, 0.03% w/w, mixed with normal chow) for 5 weeks, and then mice were intraperitoneally injected with LPS (0.25 mg kg-1) for 9 days. Our results demonstrated that LYC supplementation effectively attenuated LPS-elicited neuronal damage and synaptic dysfunction through increasing the expressions of neurotrophic factors and the synaptic proteins SNAP-25 and PSD-95. LYC ameliorated LPS-induced insulin resistance and mitochondrial dysfunction in the mouse brain and liver. LYC alleviated the neuroinflammation and hepatic inflammation. Furthermore, LYC decreased the circulating levels of insulin and proinflammatory mediators LPS, TNF-α, IL-1β and IL-6. In conclusion, these results indicated that the supplementation of LYC might be a nutritional preventive strategy in systemic inflammation-induced synaptic dysfunction.

ApoE-Dependent Protective Effects of Sesamol on High-Fat Diet-Induced Behavioral Disorders: Regulation of the Microbiome-Gut-Brain Axis

Sesamol, an antioxidant lignan from sesame oil, possesses neuroprotective bioactivities. The present work was aimed to elucidate the systemic protective effects of sesamol on cognitive deficits and to determine the possible link between gut and brain. Wildtype and ApoE^-/- mice were treated with a high-fat diet and sesamol (0.05%, w/v, in drinking water) for 10 weeks. Behavioral tests including Morris-water maze, Y-maze, and elevated plus maze tests indicated that sesamol could only improve cognitive deficits and anxiety behaviors in wildtype. Consistently, sesamol improved synapse ultrastructure and inhibited Aβ accumulation in an ApoE-dependent manner. Moreover, sesamol prevented dietary-induced gut barrier damages and systemic inflammation. Sesamol also reshaped gut microbiome and improved the generation of microbial metabolites short-chain fatty acids. To summarize, this study revealed that the possible mechanism of neuroprotective effects of sesamol might be ApoE-dependent, and its beneficial effects on gut microbiota/metabolites could be translated into neurodegenerative diseases treatment.

Nobiletin Protects against Systemic Inflammation-Stimulated Memory Impairment via MAPK and NF-κB Signaling Pathways

Neuroinflammation has been intensively demonstrated to be related to various neurodegenerative diseases including Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS), and Alzheimer's disease (AD). A natural polymethoxylated flavone, nobiletin (NOB) has been reported to alleviate oxidative stress, insulin resistance, and obesity. In this study, we evaluated the protection effects of NOB on neuroinflammation and memory deficit. Three-month mice were administrated with NOB by oral gavage every day for 6 weeks (100 mg/kg/day); subsequently mice were injected intraperitoneally with lipopolysaccharide (LPS) for 7 days. Results of behavioral tests revealed that NOB dramatically ameliorated LPS-triggered memory deficit regarding synaptic dysfunctions and neuronal loss. Also, NOB suppressed the microglial activation and proinflammatory cytokine secretion, such as COX-2, IL-1β, TNF-α, and iNOS. Similarly, upon LPS stimulation, pretreatment NOB diminished the secretion of the proinflammatory cytokines in BV-2 microglia cells by exposure to LPS via modulating MAPKs, PI3K/AKT, and NF-κB signaling pathways. In addition, NOB alleviated LPS-amplified redox imbalance, disturbance of mitochondrial membrane potential (MMP), and dampening of the expression of protein related to mitochondrial respiration. The present study provides compelling evidence that NOB decreased LPS-stimulated neuroinflammation and memory impairment through maintaining cellular oxidative balance and blocking the NF-κB transcriptional pathway, illustrating that the nutritional compound NOB may serve as a potential approach to alleviate neuroinflammation-related diseases.

Protective effects of sesamol on systemic oxidative stress-induced cognitive impairments via regulation of Nrf2/Keap1 pathway

Oxidative stress is considered as a pivotal culprit in neurodegenerative diseases and brain aging. The aim of present study was to investigate antioxidative and neuroprotective effects of sesamol, a phenolic lignan from sesame oil, on oxidative stress induced neuron damage and memory impairments. C57BL/6J mice were treated by intraperitoneal injections of d-galactose for 8 weeks. Sesamol treatment (0.05% w/v, in drinking water) suppressed d-galactose-induced liver damages and improved HO-1 and NQO1 mRNA levels. Behavioral tests, including Y-maze test and water maze-test, revealed that sesamol significantly improved oxidative stress-induced cognitive impairments. Meanwhile, sesamol ameliorated neuronal damage and improved BDNF level in rat hippocampus. Sesamol elevated mRNA levels and protein expressions of antioxidant enzymes HO-1 and NQO1 as well as decreased inflammatory cytokines TNF-α and IL-1β in d-galactose-treated mice serum. In addition, activity of CAT and GSH level were increased in sesamol-treated mice serum. Moreover, sesamol treatment also balanced cellular redox status, protected mitochondrial dysfunction and upregulated antioxidant enzymes by activating the Nrf2 transcriptional pathway and its nuclear translocation in H2O2-treated SH-SY5Y cells. In conclusion, these results revealed that sesamol could be a potential neuroprotective agent during aging process due to its beneficial effects on liver-brain axis.

Anti-inflammatory Mechanism Involved in 4-Ethylguaiacol-Mediated Inhibition of LPS-Induced Inflammation in THP-1 Cells

4-Ethylguaiacol, a common aroma compound of baijiu (a traditional Chinese alcoholic beverage), was assessed for its potential anti-inflammatory effects in an LPS-induced THP-1 cell model. To characterize the effect of 4-ethylguaiacol on the LPS-induced inflammatory response, the mRNA and protein expression of the TLR4-MAPKs-NF-κB-IκBα-AP-1, Nrf2-HO-1, and AMPK-SIRT1 pathways were monitored by ELISA, real-time PCR, and Western blotting. On the basis of the result, 4-ethylguaiacol exerted anti-inflammatory effects at doses of 10, 100, and 500 μM (the concentration of 4-ethylguaiacol in gujinggong baijiu is in the range of 1044 ± 44 to 1661 ± 63 μg/L) and significantly mitigated LPS-induced inflammation via activation of the Nrf2-HO-1 and AMPK-SIRT1 pathways and inhibition of NF-κB and AP-1 activation, thereby markedly inhibiting the activation of inflammasomes and down-regulating the production of inflammatory cytokines. These results indicated that 4-ethylguaiacol could reverse LPS-induced inflammatory responses and is a natural, potent anti-inflammatory component in baijiu.

Lycopene Supplementation Attenuates Oxidative Stress, Neuroinflammation, and Cognitive Impairment in Aged CD-1 Mice

The carotenoid pigment lycopene (LYC) possesses several properties, including antioxidative, anti-inflammatory, and neuroprotective properties. This study examined the effects of dietary supplementation with LYC on age-induced cognitive impairment, and the potential underlying mechanisms. Behavioral tests revealed that chronic LYC supplementation alleviated age-associated memory loss and cognitive defects. Histological and immunofluorescence-staining results indicated that LYC treatment reversed age-associated neuronal damage and synaptic dysfunctions in the brain. Additionally, LYC supplementation decreased age-associated oxidative stress via suppression of malondialdehyde levels, which increased glutathione, catalase, and superoxide dismutase activities and the levels of antioxidant-enzyme mRNAs, including those of heme oxygenase 1 and NAD-(P)-H-quinone oxidoreductase-1. Furthermore, LYC supplementation significantly reduced age-associated neuroinflammation by inhibiting microgliosis (Iba-1) and downregulating related inflammatory mediators. Moreover, LYC lowered the accumulation of Aβ_1-42 in the brains of aged CD-1 mice. Therefore, LYC has the potential for use in the treatment of several age-associated chronic diseases.

Anti-Amyloid Aggregation Activity of Black Sesame Pigment: Toward a Novel Alzheimer's Disease Preventive Agent

Black sesame pigment (BSP) represents a low cost, easily accessible material of plant origin exhibiting marked antioxidant and heavy metal-binding properties with potential as a food supplement. We report herein the inhibitory properties of the potentially bioaccessible fraction of BSP following simulated gastrointestinal digestion against key enzymes involved in Alzheimer's disease (AD). HPLC analysis indicated that BSP is transformed under the pH conditions mimicking the intestinal environment and the most abundant of the released compounds was identified as vanillic acid. More than 80% inhibition of acetylcholinesterase-induced aggregation of the β-amyloid Aβ1-40 was observed in the presence of the potentially bioaccessible fraction of BSP, which also efficiently inhibited self-induced Aβ1-42 aggregation and β-secretase (BACE-1) activity, even at high dilution. These properties open new perspectives toward the use of BSP as an ingredient of functional food or as a food supplement for the prevention of AD.

Porphyromonas gingivalis, a periodontitis causing bacterium, induces memory impairment and age-dependent neuroinflammation in mice

Background

A possible relationship between periodontitis and Alzheimer's disease (AD) has been reported. However, there is limited information on the association between the Porphyromonas gingivalis (P. gingivalis) periodontal infection and the pathological features of AD. The hypothesis that P. gingivalis periodontal infection may cause cognitive impairment via age-dependent neuroinflammation was tested.

Results

Thirty 4-week-old (young) female C57BL/6 J mice were randomly divided into two groups, the control group and the experimental group. Thirty 12-month-old (middle-aged) were grouped as above. The mouth of the mice in the experimental group was infected with P. gingivalis. Morris water maze(MWM) was performed to assess the learning and memory ability of mice after 6 weeks. Moreover, the expression levels of the pro-inflammatory cytokines TNF-α, IL-6, and IL-1β in the mice brain tissues were determined by Quantitative real-time polymerase chain reaction (qRT-PCR), Enzyme Linked Immunosorbent Assay(ELISA) and immunohistochemistry. Our results showed that the learning and memory abilities of the middle-aged P. gingivalis infected mice were impaired. Moreover, the expression levels of the pro-inflammatory cytokines TNF-α, IL-6, and IL-1β in the brain tissues of the middle-aged P. gingivalis infected mice were increased.

Conclusions

These results suggest that P. gingivalis periodontal infection may cause cognitive impairment via the release of the pro-inflammatory cytokines TNF-α, IL-6, and IL-1β in the brain tissues of middle-aged mice.

Effects of Lipoic Acid on High-Fat Diet-Induced Alteration of Synaptic Plasticity and Brain Glucose Metabolism: A PET/CT and 13C-NMR Study

High-fat diet (HFD)-induced obesity is accompanied by insulin resistance and compromised brain synaptic plasticity through the impairment of insulin-sensitive pathways regulating neuronal survival, learning, and memory. Lipoic acid is known to modulate the redox status of the cell and has insulin mimetic effects. This study was aimed at determining the effects of dietary administration of lipoic acid on a HFD-induced obesity model in terms of (a) insulin signaling, (b) brain glucose uptake and neuronal- and astrocytic metabolism, and (c) synaptic plasticity. 3-Month old C57BL/6J mice were divided into 4 groups exposed to their respective treatments for 9 weeks: (1) normal diet, (2) normal diet plus lipoic acid, (3) HFD, and (4) HFD plus lipoic acid. HFD resulted in higher body weight, development of insulin resistance, lower brain glucose uptake and glucose transporters, alterations in glycolytic and acetate metabolism in neurons and astrocytes, and ultimately synaptic plasticity loss evident by a decreased long-term potentiation (LTP). Lipoic acid treatment in mice on HFD prevented several HFD-induced metabolic changes and preserved synaptic plasticity. The metabolic and physiological changes in HFD-fed mice, including insulin resistance, brain glucose uptake and metabolism, and synaptic function, could be preserved by the insulin-like effect of lipoic acid.

Athyrium multidentatum (Doll.) Ching extract induce apoptosis via mitochondrial dysfunction and oxidative stress in HepG2 cells

Athyrium multidentatum (Doll.) Ching (AMC), a unique and nutritious potherb widely distributed in china, has been extensively used in traditional Chinese medicine. Previous studies indicated that AMC extract exhibited antioxidant and antitumor properties. However, the chemical composition of AMC and molecular mechanism of AMC toxicity to HepG2 cells have not yet been elucidated. Hence, this study aimed to investigate the chemical compositions and the underlying mechanisms of the antiproliferative and apoptotic effects of AMC on HepG2. HPLC-MS analysis showed that AMC contain five compounds with chlorogenic acid accounting for 43 percent. Also, AMC strongly inhibited the cell growth and induced apoptosis and cell cycle arrest in HepG2 cells by significantly upregulating the protein expressions of Fas, Fas-L, Bax/Bcl-2, cyto-c, cleaved caspase-3, and PARP in a dose-dependent manner, which indicates AMC induces apoptosis in HepG2 cells through both intrinsic and extrinsic pathways. Moreover, AMC provoked the production of ROS, H₂O₂, and NO, modulating the PI3K/Akt, MAPK, NFκB and Nrf2 pathways and their downstream transcriptional cascades, ultimately evoked oxidative stress and apoptosis in HpeG2 cells. Further in vivo experiments demonstrated that AMC significantly suppressed the tumor growth, suggesting that AMC may be a novel promising agent for hepatocellular carcinoma treatment.

Sesamol Induces Human Hepatocellular Carcinoma Cells Apoptosis by Impairing Mitochondrial Function and Suppressing Autophagy

Sesamol, a nutritional phenolic antioxidant compound enriched in sesame seeds, has been shown to have potential anticancer activities. This study aims at characterizing the antitumor efficacy of sesamol and unveiling the importance of mitochondria in sesamol-induced effects using a human hepatocellular carcinoma cell line, HepG2 cells. Results of this study showed that sesamol treatment suppressed colony formation, elicited S phase arrest during cell cycle progression, and induced both intrinsic and extrinsic apoptotic pathway in vitro with a dose-dependent manner. Furthermore, sesamol treatment elicited mitochondrial dysfunction by inducing a loss of mitochondrial membrane potential. Impaired mitochondria and accumulated H2O2 production resulted in disturbance of redox-sensitive signaling including Akt and MAPKs pathways. Mitochondrial biogenesis was inhibited as suggested by the decline in expression of mitochondrial complex I subunit ND1, and the upstream AMPK/PGC1α signals. Importantly, sesamol inhibited mitophagy and autophagy through impeding the PI3K Class III/Belin-1 pathway. Autophagy stimulator rapamycin reversed sesamol-induced apoptosis and mitochondrial respiration disorders. Moreover, it was also shown that sesamol has potent anti-hepatoma activity in a xenograft nude mice model. These data suggest that mitochondria play an essential role in sesamol-induced HepG2 cells death, and further research targeting mitochondria will provide more chemotherapeutic opportunities.

Sesamol ameliorates high-fat and high-fructose induced cognitive defects via improving insulin signaling disruption in the central nervous system

The present study demonstrated that sesamol prevents high-fat and high-fructose diet induced systemic insulin resistance and cognitive defects via stimulating PI3K/Akt signaling, improving ERK/CREB/BDNF cascades, and preserving mitochondrial function.