Synaptic modification by L-theanine, a natural constituent in green tea, rescues the impairment of hippocampal long-term potentiation and memory in AD mice

DCC, a potential target for controlling fear memory extinction and hippocampal LTP in male mice receiving single prolonged stress

Post-traumatic stress disorder (PTSD) is a severe stress-dependent psychiatric disorder characterized by impairment of fear memory extinction; however, biological markers to determine impaired fear memory extinction in PTSD remain unclear. In male mice with PTSD-like behaviors elicited by single prolonged stress (SPS), 19 differentially expressed proteins in the hippocampus were identified compared with controls. Among them, a biological macromolecular protein named deleted in colorectal cancer (DCC) was highly upregulated. Specific overexpression of DCC in the hippocampus induced similar impairment of long-term potentiation (LTP) and fear memory extinction as observed in SPS mice. The impairment of fear memory extinction in SPS mice was improved by inhibiting the function of hippocampal DCC using a neutralizing antibody. Mechanistic studies have shown that knocking down or inhibiting μ-calpain in hippocampal neurons increased DCC expression and induced impairment of fear memory extinction. Additionally, SPS-triggered impairment of hippocampal LTP and fear memory extinction could be rescued through activation of the Rac1-Pak1 signaling pathway. Our study provides evidence that calpain-mediated regulation of DCC controls hippocampal LTP and fear memory extinction in SPS mice, which likely through activation of the Rac1-Pak1 signaling pathway.

Improvement of both human and animal memory by synergy between fructooligosaccharide and L-theanine function establishing a safe and effective food supplement

Aging is classically associated with a decline of cognitive abilities, especially in relation to memory. While the development of potential treatments for neurodegenerative diseases has been in sharp focus, mild cognitive impairment (MCI), a form of age-related memory loss, in the absence of severe functional impairment, a condition experienced by many healthy adults, has received relatively little attention. Advances in this space would make significant contributions to the goal of healthy aging and may also help promote cognitive performance across the wider population. The individual action of either fructooligosaccharide (FOS) or L-theanine, both natural plant-derived molecules, has been tentatively linked with improvements in cognition, but our understanding remains far from complete. We therefore determined the effect of different dose combinations of FOS and L-theanine (termed MT-01/GBL-Memory1) in mice against FOS and L-theanine monotherapy. FOS and L-theanine were found to synergistically enhance murine memory in our animal tests at a dose of 100 mg/kg (coefficient of drug interaction (CDI) < 1). In a subsequent human trial, we demonstrated that MT-01 improved the memory of healthy adults after 1 month of consumption. Our results suggest that a combination of FOS and L-theanine synergistically enhances murine memory within a specific dose range. We show that this plant natural product regimen also improves human memory in a population of healthy adults. MT-01 therefore represents a novel, safe, and effective dietary supplement to promote human memory and cognition.

L-Theanine Prolongs the Lifespan by Activating Multiple Molecular Pathways in Ultraviolet C-Exposed Caenorhabditis elegans

L-theanine, a unique non-protein amino acid, is an important bioactive component of green tea. Previous studies have shown that L-theanine has many potent health benefits, such as anti-anxiety effects, regulation of the immune response, relaxing neural tension, and reducing oxidative damage. However, little is known concerning whether L-theanine can improve the clearance of mitochondrial DNA (mtDNA) damage in organisms. Here, we reported that L-theanine treatment increased ATP production and improved mitochondrial morphology to extend the lifespan of UVC-exposed nematodes. Mechanistic investigations showed that L-theanine treatment enhanced the removal of mtDNA damage and extended lifespan by activating autophagy, mitophagy, mitochondrial dynamics, and mitochondrial unfolded protein response (UPRmt) in UVC-exposed nematodes. In addition, L-theanine treatment also upregulated the expression of genes related to mitochondrial energy metabolism in UVC-exposed nematodes. Our study provides a theoretical basis for the possibility that tea drinking may prevent mitochondrial-related diseases.

Trends and hotspots in tea and Alzheimer's disease research from 2014 to 2023: A bibliometric and visual analysis

Objectives

The positive effects of tea on Alzheimer's disease (AD) have increasingly captured researchers' attention. Nevertheless, the quantitative comprehensive analysis in the relevant literatur is lack. This paper aims to thoroughly examine the current research status and hotspots from 2014 to 2023, providing a valuable reference for subsequent research.

Methods

Documents spanning from 2014 to 2023 were searched from the Web of Science, and the R software, VOSviewer, and Citespace software were used for analysis and visualization.

Results

A total of 374 documents were contained in the study. The rate of article publications exhibited a consistent increase each year from 2014 to 2023. Notably, China emerged as the leading country in terms of published articles, followed by the United States and India. Simultaneously, China is also in a leading position in cooperation with other countries. Molecules emerged as the most frequently published journal, while the Journal of Alzheimer's Disease secured the top spot in terms of citations. The identified main keywords included oxidative stress, amyloid, epigallocatechin gallate, and green tea polyphenol, among others. These focal areas delved into the antioxidative and anti-amyloid aggregation actions of tea's polyphenolic components. Furthermore, the particularly way in which epigallocatechin gallate delivers neuroprotective outcomes by influencing molecules related to AD represents a focal point of research.

Conclusion

The increasing attention from researchers on the role of tea in ameliorating AD positions it as a hot spot in the development of anti-AD drugs in the development of future. Through our generalized analysis of the current landscape and hotspots regarding tea's application in AD, this study provides an estimable reference for future research endeavors.

Regulatory Effects and Mechanisms of L-Theanine on Neurotransmitters via Liver-Brain Axis Under a High Protein Diet

Excessive protein intake causes liver and brain damage and neurotransmitter disorders, thereby inducing cognitive dysfunction. L-theanine can regulate the neurotransmitter content and show great potential in liver and brain protection. However, it remains unclear whether l-theanine effectively regulates neurotransmitter content under high-protein diet. A 40-day feeding experiment was performed in Sprague Dawley rats to investigate the regulatory effects and mechanisms of l-theanine on neurotransmitters via liver-brain axis in high-protein diets. The results showed that a 30% protein diet increased the liver and brain neurotransmitter content while maintaining the normal structure of liver and the hippocampal CA1 of brain and improving the autonomous behavior of rats. In contrast, 40% and 50% protein diets decreased the content of neurotransmitters, affected autonomous behavior, destroyed the hippocampal CA1 of brain structure, increased hepatic inflammatory infiltration, lipid degeneration, and hepatocyte eosinophilic change in liver, increased liver AST, ALT, MDA, CRP, and blood ammonia level, and decreased liver SOD and CAT level. However, l-theanine improved liver and brain neurotransmitter content, autonomous behavior, liver and hippocampal brain structure, and liver biochemical indicators in 40% and 50% protein diets. To explore how LTA can eliminate the adverse effects of a high-protein diet, we analyzed different metabolites and proteomes and using western blotting for validate quantitatively. We found that l-theanine regulates the activity of PF4 and G protein subunit alpha i2, increases the content of brain-derived neurotrophic factor and dopamine under a 20% protein diet. In addition, l-theanine can activate the adenylate cyclase-protein kinase A pathway through the protein alpha/beta-hydrolase domain protein 12 to regulate the content of neurotransmitters under a 40% protein diet, thereby exerting a neuroprotective effect.

Comprehensive Review of Nutraceuticals against Cognitive Decline Associated with Alzheimer's Disease

Nowadays, nutraceuticals are being incorporated into functional foods or used as supplements with nonpharmacological approaches in the prevention and management of several illnesses, including age-related conditions and chronic neurodegenerative diseases. Nutraceuticals are apt for preventing and treating such disorders because of their nontoxic, non-habit-forming, and efficient bioactivities for promoting neurological well-being due to their ability to influence cellular processes such as neurogenesis, synaptogenesis, synaptic transmission, neuro-inflammation, oxidative stress, cell death modulation, and neuronal survival. The capacity of nutraceuticals to modify all of these processes reveals the potential to develop food-based strategies to aid brain development and enhance brain function, prevent and ameliorate neurodegeneration, and possibly reverse the cognitive impairment observed in Alzheimer's disease, the most predominant form of dementia in the elderly. The current review summarizes the experimental evidence of the neuroprotective capacity of nutraceuticals against Alzheimer's disease, describing their mechanisms of action and the in vitro and in vivo models applied to evaluate their neuroprotective potential.

Special tea products featuring functional components: Health benefits and processing strategies

The functional components in tea confer various potential health benefits to humans. To date, several special tea products featuring functional components (STPFCs) have been successfully developed, such as O-methylated catechin-rich tea, γ-aminobutyric acid-rich tea, low-caffeine tea, and selenium-rich tea products. STPFCs have some unique and enhanced health benefits when compared with conventional tea products, which can meet the specific needs and preferences of different groups and have huge market potential. The processing strategies to improve the health benefits of tea products by regulating the functional component content have been an active area of research in food science. The fresh leaves of some specific tea varieties rich in functional components are used as raw materials, and special processing technologies are employed to prepare STPFCs. Huge progress has been achieved in the research and development of these STPFCs. However, the current status of these STPFCs has not yet been systematically reviewed. Here, studies on STPFCs have been comprehensively reviewed with a focus on their potential health benefits and processing strategies. Additionally, other chemical components with the potential to be developed into special teas and the application of tea functional components in the food industry have been discussed. Finally, suggestions on the promises and challenges for the future study of these STPFCs have been provided. This paper might shed light on the current status of the research and development of these STPFCs. Future studies on STPFCs should focus on screening specific tea varieties, identifying new functional components, evaluating health-promoting effects, improving flavor quality, and elucidating the interactions between functional components.

7,8-Dihydroxyflavone and Neuropsychiatric Disorders: A Translational Perspective from the Mechanism to Drug Development

7,8-Dihydroxyflavone (7,8-DHF) is a kind of natural flavonoid with the potential to cross the blood-brain barrier. 7,8-DHF effectively mimics the effect of brain-derived neurotrophic factor (BDNF) in the brain to selectively activate tyrosine kinase receptor B (TrkB) and downstream signaling pathways, thus playing a neuroprotective role. The preclinical effects of 7,8-DHF have been widely investigated in neuropsychiatric disorders, including Alzheimer's disease (AD), Parkinson's disease (PD), depression, and memory impairment. Besides the effect on TrkB, 7,8-DHF could also function through fighting against oxidative stress, cooperating with estrogen receptors, or regulating intestinal flora. This review focuses on the recent experimental studies on depression, neurodegenerative diseases, and learning and memory functions. Additionally, the structural modification and preparation of 7,8-DHF were also concluded and proposed, hoping to provide a reference for the follow-up research and clinical drug development of 7,8-DHF in the field of neuropsychiatric disorders.

Green Tea (Camellia sinensis): A Review of Its Phytochemistry, Pharmacology, and Toxicology

Objectives Green tea (Camellia sinensis) is a kind of unfermented tea that retains the natural substance in fresh leaves to a great extent. It is regarded as the second most popular drink in the world besides water. In this paper, the phytochemistry, pharmacology, and toxicology of green tea are reviewed systematically and comprehensively. Key findings Green tea has been demonstrated to be good for human health. Nowadays, multiple pharmacologically active components have been isolated and identified from green tea, including tea polyphenols, alkaloids, amino acids, polysaccharides, and volatile components. Recent studies have demonstrated that green tea shows versatile pharmacological activities, such as antioxidant, anticancer, hypoglycemic, antibacterial, antiviral, and neuroprotective. Studies on the toxic effects of green tea extract and its main ingredients have also raised concerns including hepatotoxicity and DNA damage. Summary Green tea can be used to assist the treatment of diabetes, Alzheimer’s disease, oral cancer, and dermatitis. Consequently, green tea has shown promising practical prospects in health care and disease prevention.

A comprehensive review on the prevention and regulation of Alzheimer's disease by tea and its active ingredients

Alzheimer's disease (AD) has brought a heavy burden to society as a representative neurodegenerative disease. The etiology of AD combines multiple factors, concluding family, gender, head trauma, diseases and social psychology. There are multiple hypotheses explaining the pathogenesis of AD such as β-amyloid (Aβ) deposition and tau hyperphosphorylation, which lead to extracellular amyloid plaques and neurofibrillary tangles in neurons. The existing therapeutic drugs have several disadvantages including single target, poor curative effect, and obvious side effects. Tea contains many bioactive components, such as tea polyphenols (TPP), L-theanine (L-TH), tea pigment, tea polysaccharides and caffeine. The epidemiological investigations have shown that drinking tea can reduce the risk of AD. The mechanisms of tea active ingredients in the prevention and regulation of AD includes reducing the generation and aggregation of Aβ; inhibiting tau aggregation and hyperphosphorylation; inhibiting neuronal apoptosis and regulate neurotransmitters; relieving oxidative stress and neuroinflammation as well as the regulation of intestinal flora. This review summarizes the different signaling pathways that tea active ingredients regulate AD. Furthermore, we propose the main limitations of current research and future research directions, hoping to contribute to the development of natural functional foods based on tea active ingredients in the prevention and treatment of AD.

Understanding How Physical Exercise Improves Alzheimer’s Disease: Cholinergic and Monoaminergic Systems

Alzheimer’s disease (AD) is an age-related neurodegenerative disorder, characterized by the accumulation of proteinaceous aggregates and neurofibrillary lesions composed of β-amyloid (Aβ) peptide and hyperphosphorylated microtubule-associated protein tau, respectively. It has long been known that dysregulation of cholinergic and monoaminergic (i.e., dopaminergic, serotoninergic, and noradrenergic) systems is involved in the pathogenesis of AD. Abnormalities in neuronal activity, neurotransmitter signaling input, and receptor function exaggerate Aβ deposition and tau hyperphosphorylation. Maintenance of normal neurotransmission is essential to halt AD progression. Most neurotransmitters and neurotransmitter-related drugs modulate the pathology of AD and improve cognitive function through G protein-coupled receptors (GPCRs). Exercise therapies provide an important alternative or adjunctive intervention for AD. Cumulative evidence indicates that exercise can prevent multiple pathological features found in AD and improve cognitive function through delaying the degeneration of cholinergic and monoaminergic neurons; increasing levels of acetylcholine, norepinephrine, serotonin, and dopamine; and modulating the activity of certain neurotransmitter-related GPCRs. Emerging insights into the mechanistic links among exercise, the neurotransmitter system, and AD highlight the potential of this intervention as a therapeutic approach for AD.

L-Theanine: A Unique Functional Amino Acid in Tea (Camellia sinensis L.) With Multiple Health Benefits and Food Applications

Tea (Camellia sinensis L.) is a very popular health drink and has attracted increasing attention in recent years due to its various bioactive substances. Among them, L-theanine, a unique free amino acid, is one of the most important substances in tea and endows tea with a special flavor. Moreover, L-theanine is also a bioactive compound with plenty of health benefits, including antioxidant, anti-inflammatory, neuroprotective, anticancer, metabolic regulatory, cardiovascular protective, liver and kidney protective, immune regulatory, and anti-obesity effects. Due to the unique characteristics and beneficial functions, L-theanine has potential applications in the development of functional foods. This review summarized the influencing factors of L-theanine content in teas, the main health benefits and related molecular mechanisms of L-theanine, and its applications in food, understanding of which can provide updated information for the further research of L-theanine.

The Effects of Moxibustion on Learning and Memory and m6A RNA Methylation in APP/PS1 Mice

Objectives

To study whether moxibustion can improve the learning and memory ability of APP/PS1 mice by reducing the pathological products Aβ and Tau protein via decreasing N6-methyladenosine (m6A).

Methods

APP/PS1 mice were randomly divided into model group (APP/PS1) and moxibustion group (APP/PS1+Mox). C57BL/6J mice were used as a control group (Control). Learning and memory abilities were assessed by the Morris water maze. Aβ, Tau, phosphorylated Tau (p-Tau), and YTHDF1 proteins were detected in the mouse cortex and hippocampus by immunofluorescence and western blot. Altered m6A expression levels in hippocampal and cortical tissues were measured with the m6A RNA methylation quantification assay kit. RNA transcript levels of YTHDF1, METTL3, and FTO in the hippocampus and cortex were measured by q-PCR.

Results

Moxibustion shortened the escape latency, increased the number of platform crossings, and increased the percentage of swimming time in the target quadrant of APP/PS1 mice. Meanwhile, moxibustion reduced the levels of Aβ, Tau, and p-Tau proteins both in the hippocampal and cortical regions of APP/PS1 mice. In addition, the total amount of m6A in the hippocampal and cortical regions of APP/PS1 mice was significantly reduced after moxibustion. The expression of YTHDF1 in the hippocampal region of APP/PS1 mice increased and that in the cortical region decreased after moxibustion treatment.

Conclusion

Moxibustion improves the learning and memory abilities and reduces the deposition of Aβ and Tau protein pathological products in APP/PS1 mice. This may be related to the fact that moxibustion reduces the total amount of m6A and inhibits its binding enzyme YTHDF1 in the hippocampus and cortex of APP/PS1 mice.

Green Tea Suppresses Amyloid β Levels and Alleviates Cognitive Impairment by Inhibiting APP Cleavage and Preventing Neurotoxicity in 5XFAD Mice

SCOPE

The consumption of green tea is considered to be associated with a lower incidence of neurodegenerative diseases. In the present study, it is investigated the role of amyloid precursor protein cleavage, glial cell activation, neuroinflammation, and synaptic alterations in the protective effects of green tea against the amyloid β (Aβ) accumulation and cognitive impairment.

METHODS AND RESULTS

5XFAD mice are treated with green tea extract (GTE) for 8 or 16 weeks. Barnes maze and Y maze testing demonstrated that spatial learning and memory ability are markedly improved by GTE treatment. Immunofluorescence staining, ELISA, and western blot showed GTE significantly alleviate the formation of Aβ and reduce the levels of sAPPβ and C99, as well as sAPPα and C83. Meanwhile, GTE suppressed GFAP and Iba1 levels in the glial cells, increased PSD95 and synaptophysin levels in synaptic cells. Further, the IL-1β level is decreased, RNA sequencing reveals the genes annotated in response to stimulus and immune response are regulated.

CONCLUSION

Our findings indicate GTE suppresses Aβ levels and alleviate cognitive impairment in 5XFAD mice. These beneficial effects are accompanied by inhibition of APP cleavage pathways, suppression of glial cell activation and pro-inflammatory responses, and a reduction of synapse loss.

Effects of a Tea Cultivar "MK5601" on Behaviors and Hippocampal Neurotrophin-3 Levels in Middle-Aged Mice

Dietary factors are thought to play an important role in the prevention of cognition diseases and depression in late life. In the present study, we compared the effects between the theogallin-rich tea cultivar, "MK5601" and a common Japanese tea cultivar, "Yabukita" on behaviors and hippocampal neurotrophin levels in experimental animals. Middle-aged mice (aged 8 mo) were given either of the tea infusions or water ad libitum for 4 mo. In the novel object location test, the middle-aged mice drinking water or "Yabukita" performed worse than young mice (aged 2-3 mo) although the middle-aged mice drinking "MK5601" retained spatial memory at the same level as the young mice. We also found that the middle-aged mice drinking "MK5601" showed high levels of neurotrophin-3 in the hippocampus. In conclusion, the "MK5601" tea infusion appears to be effective in preventing age-related changes in cognitive function, as compared with a common Japanese tea cultivar.

Albanin A, Derived from the Root Bark of Morus alba L., Depresses Glutamate Release in the Rat Cerebrocortical Nerve Terminals via Ca2+/Calmodulin/Adenylate Cyclase 1 Suppression

Decreasing synaptic release of glutamate may counteract glutamate excitotoxicity in many neurological diseases. In this study, we investigated the effect of albanin A, a constituent in the root bark of Morus alba L., on the release of glutamate in rat cerebral cortex nerve endings (synaptosomes). We found that albanin A at 5-30μM suppressed 4-aminopyridine (4-AP)-induced release of glutamate. This phenomenon was abolished by extracellular calcium removal or by vesicular transporter inhibition, and was associated with a decrease in intrasynaptosomal Ca²⁺ levels. However, albanin A had no effect on the synaptosomal membrane potential. The inhibition of N- and P/Q-type Ca²⁺ channels, calmodulin, adenylate cyclase (AC), and protein kinase A, abolished the effect of albanin A on the glutamate release evoked by 4-AP. Moreover, the albanin A-mediated inhibition of glutamate release was prevented by the Ca²⁺/calmodulin-stimulated AC1 inhibitor. Western blot showed that AC1, but not AC8, was presented in the synaptosomes, and albanin A reduced 4-AP-induced increases in synaptosomal cyclic adenosine monophosphate content. In addition, albanin A pretreatment substantially attenuated neuronal damage in a rat model of kainic acid-induced glutamate excitotoxicity. Our data reveal that albanin A suppresses glutamate release by decreasing Ca²⁺/calmodulin/AC1 activation in synaptosomes and exerts neuroprotective effect in vivo.

Ginsenoside Rg1 Prevents PTSD-Like Behaviors in Mice Through Promoting Synaptic Proteins, Reducing Kir4.1 and TNF-α in the Hippocampus

Ginsenoside Rg1 is efficient to prevent or treat mental disorders. However, the mechanisms underlying the effects of ginsenoside Rg1 on post-traumatic stress disorder (PTSD) are still not known. In this study, single-prolonged stress (SPS) regime, as well as injection of lipopolysaccharide (LPS), was used to produce PTSD-like behaviors in C57 mice, and the effects of ginsenoside Rg1 (10, 20, 40 mg/kg/d, ip, for 14 days) on PTSD-like behaviors were evaluated. Our results showed that ginsenoside Rg1 promoted fear extinction and prevented depression-like behaviors in both LPS and SPS models. Importantly, ginsenoside Rg1 alleviated LPS- or SPS-stimulated expression of pro-inflammatory cytokines (IL-1β and TNF-α), activation of astrocytes and microglia, and reduction of hippocampal synaptic proteins (PSD95, Arc, and GluA1). Ginsenoside Rg1 also reduced the increase of hippocampal Kir4.1 and GluN2A induced by PTSD regime. Importantly, reducing hippocampal astroglial Kir4.1 expression promoted fear extinction and improved depression-like behaviors in LPS-treated mice. Additionally, intracerebroventricular injection of TNF-α caused an impairment of fear extinction and promoted Kir4.1 expression in the hippocampus. Together, our study reveals novel protective effects of ginsenoside Rg1 against PTSD-like behaviors in mice, likely via promoting synaptic proteins, reducing Kir4.1 and TNF-α in the hippocampus.

Green Tea, A Medicinal Food with Promising Neurological Benefits

Neurological disorders and their sequelae, as of the widespread and critical humans’ complications, affect the body's nervous systems, organ functions, and behaviors. According to WHO, neurological disorders are currently predicted to affect more than one billion people globally. It is well-established that complementary medicine is one of the high accepted interventions that could have been considered for the management of neurological ailments. The current review aimed to compile all the crucial data reporting the investigation on the conspicuous intervention of green tea (made of Camellia sinensis) and related lead compounds (especially l-theanine, epigallocatechin-3-gallate, epicatechin-3-gallate, epicatechin, and epigallocatechin) for their neurological activities, mechanisms of action, and clinical properties. According to the documents, green tea exhibits antidepressant, anti-neurodegenerative (e.g., anti-Parkinson and anti-Alzheimer), as well as neuroprotective effects.Chief among them, for offering novel work, it is worth focusing on several related assessments with great attention to more extensive standardized clinical trials, and subsequently more in-depth pharmacokinetic studies to safely introduce this beneficial medicinal food as a neuro-effective agent.

Alterations in cyclic nucleotide signaling are implicated in healthy aging and age-related pathologies of the brain

It is not only important to consider how hormones may change with age, but also how downstream signaling pathways that couple to hormone receptors may change. Among these hormone-coupled signaling pathways are the 3',5'-cyclic guanosine monophosphate (cGMP) and 3',5'-cyclic adenosine monophosphate (cAMP) intracellular second messenger cascades. Here, we test the hypothesis that dysfunction of cAMP and/or cGMP synthesis, execution, and/or degradation occurs in the brain during healthy and pathological diseases such as Alzheimer's disease, Parkinson's disease, and Huntington's disease. Although most studies report lower cyclic nucleotide signaling in the aged brain, with further reductions noted in the context of age-related diseases, there are select examples where cAMP signaling may be elevated in select tissues. Thus, therapeutics would need to target cAMP/cGMP in a tissue-specific manner if efficacy for select symptoms is to be achieved without worsening others.

Reducing LncRNA-5657 expression inhibits the brain inflammatory reaction in septic rats

Our preliminary study found that the long noncoding RNA (LncRNA)-5657 can reduce the expression of inflammatory factors during inflammatory reactions in rat glial cells. However, the role played by LncRNA-5657 during septic brain injury remains unclear. In the present study, rat models of septic encephalopathy were established by cecal ligation and puncture, and then the rats were treated with a hippocampal injection small hairpin RNA (shRNA) against LncRNA-5657 (sh-LnCRNA-5657). The sh-LncRNA-5657 treatment reduced the level of neuronal degeneration and necrosis in the rat hippocampus, reduced the immunoreactivities of aquaporin 4, heparanase, and metallopeptidase-9, and lowered the level of tumor necrosis factor-alpha. Glial cells were pre-treated with sh-LncRNA-5657 and then treated with 1 µg/mL lipopolysaccharide. Sh-LncRNA-5657 transfection decreased the expression of LncRNA-5657 in lipopolysaccharide-treated glial cells and decreased the mRNA and protein levels of tumor necrosis factor-alpha, interleukin-1β, and interleukin-6. These findings suggested that LncRNA-5657 expression can significantly reduce the inflammatory reaction during septic encephalopathy and induce protective effects against this disease. This study was approved by the Institutional Ethics Committee at the First Affiliated Hospital of Nanchang University of China (approval No. 2017-004) in 2017.

Effects of Matcha Green Tea Powder on Cognitive Functions of Community-Dwelling Elderly Individuals

Matcha Green Tea Powder contains a variety of active ingredients beneficial to health, such as tea catechins, lutein and vitamin K. It is also known that these ingredients confer benefits upon cognitive functions of elderly people. Therefore, we aimed to investigate the relationship between a daily supplementation of Matcha and the change in cognitive functions of community-dwelling elderly people. A randomized, double-blind, placebo-controlled 12-week trial was performed. Sixty-one participants were recruited and randomly assigned to receive test drink containing 3 g powder from fresh Matcha or placebo powder per day. Changes in cognitive function were assessed utilizing a psychometric test battery. Daily food intake was assessed by a Brief-type Self-administered Diet History Questionnaire (BDHQ). In the gender-specific analysis, a significant cognitive enhancement was observed in the Montreal Cognitive Assessment (MoCA) score in the active group of women. In dietary analysis, we found a significant inverse correlation between consumption of vitamin K in daily diet, excluding test drinks, and change in MoCA. The present study suggests that daily supplementation of Matcha Green Tea Powder has protective effects against cognitive decline in community-dwelling elderly women.

Effects of Co-Administration of Icariin and Panax notoginseng Saponins on Intestinal Microbiota and Hippocampal Protein Expression in a Mouse Model of Alzheimer's Disease

OBJECTIVE

We investigated the effect of icariin (ICA) combined with Panax notoginseng saponins (PNS) on intestinal microbiota and hippocampal protein expression in amyloid precursor protein/presenilin 1 (APP/PS1) transgenic mice, a model of Alzheimer's disease (AD).

METHODS

Transgenic mice were treated with icariin and PNS. The Morris water maze (MWM) was used to assess spatial memory, and the gut microbiota and differential protein expression in the hippocampus were investigated using high-throughput screening techniques. Differential protein expression was confirmed by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting.

RESULTS

The MWM results showed that the mice treated with the medium dose of ICA+PNS spent significantly more time in the target quadrant compared with the AD group. Bacterial diversity was the lowest in the AD group, with significantly greater diversity in the ICA + PNS treatment group. Three proteins were selected for proteomic analysis, and qRT-PCR and Western blot were used to detect the expression of 2'-5'-oligoadenylate synthetase ubiquitin like 1 (Oasl1), trichoplein keratin filament-binding protein (TCHP), and tumor necrosis factor receptor associated 3-interacting protein 1 (MIPT3). Compared with control mice, MIPT3 expression was increased and Oasl1 and TCHP were reduced in the AD group. These abnormal protein expressions tended to normalization after treatment with medium dose of ICA and PNS.

CONCLUSION

Treatment with ICA and PNS ameliorated memory impairment in an AD mouse model. The mechanisms may be related to modulation of the intestinal microbiota and expression of Oasl1, TCHP, and MIPT3.

Efficient synthesis of γ-glutamyl compounds by co-expression of γ-glutamylmethylamide synthetase and polyphosphate kinase in engineered Escherichia coli

γ-Glutamyl compounds have unveiled their importance as active substances or precursors of pharmaceuticals. In this research, an approach for enzymatic synthesis of γ-glutamyl compounds was developed using γ-glutamylmethylamide synthetase (GMAS) from Methylovorus mays and polyphosphate kinase (PPK) from Corynebacterium glutamicum. GMAS and PPK were co-recombined in pETDuet-1 plasmid and co-expressed in E. coli BL21 (DE3), and the enzymatic properties of GMAS and PPK were investigated, respectively. Under the catalysis of the co-expression system, L-theanine was synthesized with 89.8% conversion when the substrate molar ratio of sodium glutamate and ethylamine (1:1.4) and only 2 mM ATP were used. A total of 14 γ-glutamyl compounds were synthesized by this one-pot method and purified by cation exchange resin and isoelectric point crystallization with a yield range from 22.3 to 72.7%. This study provided an efficient approach for the synthesis of γ-glutamyl compounds by GMAS and PPK co-expression system.

Astragaloside IV prevents Aβ1-42 oligomers-induced memory impairment and hippocampal cell apoptosis by promoting PPARγ/BDNF signaling pathway

Astragaloside IV (AS-IV), a natural product derived from Radix Astragali (Astragalus membranaceus), is beneficial for the treatment of Alzheimer's disease (AD), but the mechanisms underlying this benefit are not completely understood. Peroxisome proliferator-activated receptor gamma (PPARγ) and brain-derived neurotrophic factor (BDNF) are potential therapeutic targets for AD. In this study, we found that amyloid β protein fragment 1-42 oligomers (AβO) suppressed BDNF and PPARγ expression, and inhibited tyrosine receptor kinase B (TrkB) phosphorylation in cultured hippocampal neurons; these changes were ameliorated by treatment with AS-IV. Inhibition of PPARγ by genetic and pharmacological methods also blocked the effect of AS-IV on BDNF expression in AβO-treated cells. Importantly, exogenous BDNF protected against neurotoxicity and apoptosis induced by AβO, whereas inhibition of PPARγ reversed protective effects of AS-IV against these outcomes. In vivo data further revealed that AS-IV improved AβO-induced memory impairment and reduced apoptosis of hippocampal neurons. Moreover, AS-IV suppressed the AβO-induced reduction in BDNF by promoting PPARγ activation in the hippocampus. Taken together, these results indicate that AS-IV prevents AβO-induced memory impairment and hippocampal neuronal apoptosis, probably by promoting the PPARγ/BDNF signaling pathway.

The Effects of microRNA-515-5p on the Toll-Like Receptor 4 (TLR4)/JNK Signaling Pathway and WNT1-Inducible-Signaling Pathway Protein 1 (WISP-1) Expression in Rheumatoid Arthritis Fibroblast-Like Synovial (RAFLS) Cells Following Treatment with Receptor Activator of Nuclear Factor-kappa-B Ligand (RANKL)

BACKGROUND This study aimed to investigate the effects of microRNA-515-5p (miR-515-5p) on the expression of the WNT1-inducible-signaling pathway protein 1 (WISP-1) gene in rheumatoid arthritis fibroblast-like synovial (RAFLS) cells following treatment with the receptor activator of nuclear factor-kappa-B ligand (RANKL). MATERIAL AND METHODS RAFLS cells were cultured in vitro and were divided into six study groups: a normal control group; a miR-515-5p mimic group; a miR-515-5p inhibitor group; a RANKL (50 ng/ml) treatment group; a miR-515-5p mimic+RANKL treatment group; and a miR-515-5p inhibitor+RANKL treatment group. The luciferase assay was used to determine the effects of miR-515-5p on the WISP1 expression. Cell proliferation, cell apoptosis, the cell cycle, and protein expression were determined using the Cell Counting Kit-8 (CCK-8) assay, flow cytometry, Western blot, and real-time polymerase chain reaction (RT-PCR). RESULTS The luciferase assay showed that the effects of miR-515-on the 3'-UTR of WISP1 inhibited the gene expression. The miR-515-5p mimics promoted cell proliferation, reduced apoptosis, and promoted the cell cycle. The miR-515-5p mimics reduced, the expression of TLR4, WISP1, and JNK at the mRNA level, while the miR-515-5p inhibitor promoted the expression of TLR4, WISP1, and JNK. Both the miR-515-5p inhibitor and mimic promoted the phosphorylation of AKT in RAFLS cells treated with or without RANKL compared with the control, and the miR-515-5p inhibitor promoted the phosphorylation of JNK in the RAFLS cells. CONCLUSIONS In RAFLS cells, miR-515-5p inhibited the expression of the WISP1 gene, and treatment with RANKL inhibited the TLR4/JNK signaling pathway.

Effects of Exercise on Long-Term Potentiation in Neuropsychiatric Disorders

Various neuropsychiatric conditions, such as depression, Alzheimer's disease, and Parkinson's disease, demonstrate evidence of impaired long-term potentiation, a cellular correlate of episodic memory function. This chapter discusses the mechanistic effects of these neuropsychiatric conditions on long-term potentiation and how exercise may help to attenuate these detrimental effects.

Vibrational (FT-IR, Raman) analysis of tea catechins based on both theoretical calculations and experiments

Structural investigations, based on density functional theory (DFT) calculations, are performed on tea catechins, including 4-aminobutyric acid (GABA), L-theanine (Thea), caffeine (CAF), theobromine (TB), theophylline (TP), catechin (C), epicatechin (EC), gallocatechin (GC), epigallocatechin (EGC), catechin gallate (CG), epicatechin gallate (ECG), gallocatechin gallate (GCG) and epigallocatechin gallate (EGCG). With an identified lowest energy conformer of investigated molecules, FTIR and FT-Raman spectra have been assigned according to DFT calculations in the way of B3LYP/6-31 + G (d, p). Normal spectra of these catechin powders are also measured by Raman spectrometers. There is a kind of everlasting correlation between experimental results and theoretical data. And our research has also obtained a clear evidence for reliable assignments of vibrational bands, bringing great feasibility to the rapid tea catechin detection.

Mechanisms Underlying the Anti-Depressive Effects of Regular Tea Consumption

This article is a comprehensive review of the literature pertaining to the antidepressant effects and mechanisms of regular tea consumption. Meta-data supplemented with recent observational studies were first analyzed to assess the association between tea consumption and depression risk. The literature reported risk ratios (RR) were 0.69 with 95% confidence intervals of 0.62-0.77. Next, we thoroughly reviewed human trials, mouse models, and in vitro experiments to determine the predominant mechanisms underlying the observed linear relationship between tea consumption and reduced risk of depression. Current theories on the neurobiology of depression were utilized to map tea-mediated mechanisms of antidepressant activity onto an integrated framework of depression pathology. The major nodes within the network framework of depression included hypothalamic-pituitary-adrenal (HPA) axis hyperactivity, inflammation, weakened monoaminergic systems, reduced neurogenesis/neuroplasticity, and poor microbiome diversity affecting the gut-brain axis. We detailed how each node has subsystems within them, including signaling pathways, specific target proteins, or transporters that interface with compounds in tea, mediating their antidepressant effects. A major pathway was found to be the ERK/CREB/BDNF signaling pathway, up-regulated by a number of compounds in tea including teasaponin, L-theanine, EGCG and combinations of tea catechins and their metabolites. Black tea theaflavins and EGCG are potent anti-inflammatory agents via down-regulation of NF-κB signaling. Multiple compounds in tea are effective modulators of dopaminergic activity and the gut-brain axis. Taken together, our findings show that constituents found in all major tea types, predominantly L-theanine, polyphenols and polyphenol metabolites, are capable of functioning through multiple pathways simultaneously to collectively reduce the risk of depression.

Therapeutic Effects of Resveratrol Liposome on Muscle Injury in Rats

BACKGROUND In this study we prepared liposome microbubbles loading resveratrol (LMLR) and evaluated its therapeutic effect on injury of gastrocnemius muscle in rats. MATERIAL AND METHODS LMLR was prepared and characterized by particle size, potential, and microscopy, and a rat model of acute blunt injury of gastrocnemius muscle was established. After treatments with resveratrol or LMLR, the therapeutic effects were evaluated by hematoxylin-eosin (HE) staining. The expression of MHCIIB and vimentin in mRNA level was measured by real-time PCR. The expression of desmin and collagen I protein was assessed by immunohistochemistry. RESULTS LMLR showed regular cycle shape in a size of ~1000 nm. LMLR was negatively charged (-30 mV). The in vitro release of LMLR was close to 80% at 10 h and 90% at 48 h. Acute gastrocnemius muscle injury was established in rats and tissue recovery was observed after LMLR treatment as evidenced by HE staining, decreased expression of MHCIIB, and increased expression of vimentin. Moreover, LMLR treatment obviously facilitated desmin expression and reduced collagen I expression. CONCLUSIONS LMLR is effective in treating acute blunt injury of gastrocnemius muscle in rats.

Postnatal calpeptin treatment causes hippocampal neurodevelopmental defects in neonatal rats

Our previous studies showed that the early use of calpain inhibitors reduces calpain activity in multiple brain regions, and that postnatal treatment with calpeptin may lead to cerebellar motor dysfunction. However, it remains unclear whether postnatal calpeptin application affects hippocampus-related behaviors. In this study, Sprague-Dawley rats were purchased from the Animal Center of Anhui Medical University of China. For the experiments in the adult stage, rats were intraperitoneally injected with calpeptin, 2 mg/kg, once a day, on postnatal days 7-14. Then on postnatal day 60, the Morris water maze test was used to evaluate spatial learning and memory abilities. The open field test was carried out to assess anxiety-like activities. Phalloidin staining was performed to observe synaptic morphology in the hippocampus. Immunohistochemistry was used to count the number of NeuN-positive cells in the hippocampal CA1 region. DiI was applied to label dendritic spines. Calpeptin administration impaired spatial memory, caused anxiety-like behavior in adulthood, reduced the number and area of apical dendritic spines, and decreased actin polymerization in the hippocampus, but did not affect the number of NeuN-positive cells in the hippocampal CA1 region. For the neonatal experiments, neonatal rats were intraperitoneally injected with calpeptin, 2 mg/kg, on postnatal days 7 and 8. Western blot assay was performed to analyze the protein levels of Akt, Erk, p-Akt, p-Erk1/2, Erk1/2, SCOP, PTEN, mTOR, p-mTOR, CREB and p-CREB in the hippocampus. SCOP expression was increased, and the phosphorylation levels of Akt, mTOR and CREB were reduced in the hippocampus. These findings show that calpeptin administration after birth affects synaptic development in neonatal rats by inhibiting the Akt/mTOR signaling pathway, thereby perturbing hippocampal function. Therefore, calpeptin administration after birth is a risk factor for neurodevelopmental defects.

Basolateral amygdala calpain is required for extinction of contextual fear-memory

Extinction of fear-memory is essential for emotional and mental changes. However, the mechanisms underlying extinction of fear-memory are largely unknown. Calpain is a type of calcium-dependent protease that plays a critical role in memory consolidation and reconsolidation. Whether calpain functions in extinction of fear-memory is unknown, as are the molecular mechanisms. In this study, we investigated the pivotal role of calpain in extinction of fear-memory in mice, and assessed its mechanism. Conditioned stimulation/unconditioned stimulation-conditioned stimulation paradigms combined with pharmacological methods were employed to evaluate the action of calpain in memory extinction. Our data demonstrated that intraperitoneal or intra-basolateral amygdala (BLA) injection of calpain inhibitors could eliminate extinction of fear-memory in mice. Moreover, extinction of fear-memory paradigm-activated BLA calpain activity, which degraded suprachiasmatic nucleus circadian oscillatory protein (SCOP) and phosphatase and tensin homolog (PTEN), subsequently contributing to activation of a protein kinase B (AKT)-mammalian target of the rapamycin (mTor) signaling pathway. Additionally, cAMP-response element binding protein (CREB) phosphorylation was also augmented following extinction of fear-memory. Calpain inhibitor blocked the signaling pathway activation induced by extinction of fear-memory. Additionally, intra-BLA injection of rapamycin or cycloheximide also blocked the extinction of fear-memory. Conversely, intra-BLA injection of PTEN inhibitor, bpV, reversed the effect of calpeptin on extinction of fear-memory. Together, our data confirmed the function of BLA calpain in extinction of fear-memory, likely via degrading PTEN and activating AKT-mTor-dependent protein synthesis.