Gastrodin suppresses BACE1 expression under oxidative stress condition via inhibition of the PKR/eIF2α pathway in Alzheimer's disease

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

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

Proteomic analysis reveals the antiviral effects of baicalin on pseudorabies virus

Pseudorabies virus (PRV) poses a significant threat to livestock and even humans. Baicalin, a bioactive flavonoid glycoside with medicinal potential, has been reported to have various biological activities. However, its inhibitory effect on PRV remains poorly understood. In this study, we proved that baicalin effectively inhibits PRV infection. Proteomic analysis revealed that baicalin reduces the expression of 14 viral proteins, which are associated with virus replication, release and immune evasion. Furthermore, the abundance of 116 host proteins was altered by PRV infection, but restored to normal levels after treatment with baicalin. Pathway analysis indicated that baicalin mitigates reactive oxygen species (ROS) and suppresses abnormal mitochondrion by reducing the expression of NFU1 iron‑sulfur cluster scaffold homolog (NFU1) protein induced by PRV. Notably, baicalin also activates the complete coagulation cascade by increasing the expression of coagulation factor III (F3) protein and enhances nucleoplasm by upregulating the expression of solute carrier family 3 member 2 (SLC3A2) and CCAAT enhancer binding protein beta (CEBPB) proteins, contributing to its inhibitory effects on PRV. Our findings implied that baicalin has the potential to be developed as an anti-PRV drug and provide insights into the underlying molecular basis.

Unveiling the impact of aging on BBB and Alzheimer's disease: Factors and therapeutic implications

Alzheimer's disease (AD) is a highly prevalent neurodegenerative condition that has devastating effects on individuals, often resulting in dementia. AD is primarily defined by the presence of extracellular plaques containing insoluble β-amyloid peptide (Aβ) and neurofibrillary tangles (NFTs) composed of hyperphosphorylated tau protein (P-tau). In addition, individuals afflicted by these age-related illnesses experience a diminished state of health, which places significant financial strain on their loved ones. Several risk factors play a significant role in the development of AD. These factors include genetics, diet, smoking, certain diseases (such as cerebrovascular diseases, obesity, hypertension, and dyslipidemia), age, and alcohol consumption. Age-related factors are key contributors to the development of vascular-based neurodegenerative diseases such as AD. In general, the process of aging can lead to changes in the immune system's responses and can also initiate inflammation in the brain. The chronic inflammation and the inflammatory mediators found in the brain play a crucial role in the dysfunction of the blood-brain barrier (BBB). Furthermore, maintaining BBB integrity is of utmost importance in preventing a wide range of neurological disorders. Therefore, in this review, we discussed the role of age and its related factors in the breakdown of the blood-brain barrier and the development of AD. We also discussed the importance of different compounds, such as those with anti-aging properties, and other compounds that can help maintain the integrity of the blood-brain barrier in the prevention of AD. This review builds a strong correlation between age-related factors, degradation of the BBB, and its impact on AD.

Gastrodin: a comprehensive pharmacological review

Tianma is the dried tuber of Gastrodia elata Blume (G. elata), which is frequently utilized in clinical practice as a traditional Chinese medicine. Gastrodin (GAS) is the main active ingredient of Tianma, which has good pharmacological activity. Therefore, for the first time, this review focused on the extraction, synthesis, pharmacological effects, and derivatives of GAS and to investigate additional development options for GAS. The use of microorganisms to create GAS is a promising method. GAS has good efficacy in the treatment of neurological diseases, cardiovascular diseases, endocrine diseases, and liver diseases. GAS has significant anti-inflammatory, antioxidant, neuroprotective, vascular protective, blood sugar lowering, lipid-regulating, analgesic, anticancer, and antiviral effects. The mechanism involves various signaling pathways such as Nrf2, NF-κB, PI3K/AKT, and AMPK. In addition, the derivatives of GAS and biomaterials synthesized by GAS and PU suggested a broader application of GAS. The research on GAS is thoroughly summarized in this paper, which has useful applications for tackling a variety of disorders and exhibits good development value.

Targeting pyroptosis to treat ischemic stroke: From molecular pathways to treatment strategy

Ischemic stroke is the primary reason for human disability and death, but the available treatment options are limited. Hence, it is imperative to explore novel and efficient therapies. In recent years, pyroptosis (a pro-inflammatory cell death characterized by inflammation) has emerged as an important pathological mechanism in ischemic stroke that can cause cell death through plasma membrane rupture and release of inflammatory cytokines. Pyroptosis is closely associated with inflammation, which exacerbates the inflammatory response in ischemic stroke. The level of inflammasomes, GSDMD, Caspases, and inflammatory factors is increased after ischemic stroke, exacerbating brain injury by mediating pyroptosis. Hence, inhibition of pyroptosis can be a therapeutic strategy for ischemic stroke. In this review, we have summarized the relationship between pyroptosis and ischemic stroke, as well as a series of treatments to attenuate pyroptosis, intending to provide insights for new therapeutic targets on ischemic stroke.

Gastrodin ameliorates depressive-like behaviors via modulating gut microbiota in CUMS-induced mice

PURPOSE

Depression is a psychiatric disorder and the treatment of depression is an urgent problem that need to be solved. Gastrodin (GAS) is a Traditional Chinese Medicine from an orchid and is used for neurological diseases, including depressive disorders.

METHODS

To assess the effect of GAS on gut microbiota of depressive mice, we established a chronic unpredictable mild stress (CUMS)-induced mouse model, and GAS was administered to one group of the mice. Animal behavior experiments were used to detect depressive-like behaviors, and 16 S rRNA gene analysis was applied to detect the gut microbiota of each group. All raw sequences were deposited in the NCBI Sequence Read Archive under accession number SRP491061.

RESULTS

GAS treatment significantly improved depressive-like behaviors as well as the diversity and abundance of the gut microbiota. The depressive-like behaviors of the CUMS-GAS group were improved in different degrees compared with the CUMS group. The linear discriminant analysis (LDA) of the gut microbiota showed that the makeup of the gut microbiota in mice changed dramatically in the CUMS-GAS group, compared with the CUMS group, Bacteroides (LDA = 3.94, P < 0.05) were enriched in the CUMS-GAS group at the genus level. In comparison to the CUMS group, the CUMS-GAS group had a greater concentration numbers of Lactobacillus, Corynebacterium, Staphylococcus, Bacteroides, Psychrobacter, and Alistipes.

CONCLUSION

Our results suggested that GAS improved depressive-like behaviors in mice and impacted the microbial composition of the gut. Our research indicated that dysbiosis of the gut microbiota may be affected by GAS treatment, which improved depressive-like behaviors in the CUMS-induced mouse model of depression.

Protein translation: biological processes and therapeutic strategies for human diseases

Protein translation is a tightly regulated cellular process that is essential for gene expression and protein synthesis. The deregulation of this process is increasingly recognized as a critical factor in the pathogenesis of various human diseases. In this review, we discuss how deregulated translation can lead to aberrant protein synthesis, altered cellular functions, and disease progression. We explore the key mechanisms contributing to the deregulation of protein translation, including functional alterations in translation factors, tRNA, mRNA, and ribosome function. Deregulated translation leads to abnormal protein expression, disrupted cellular signaling, and perturbed cellular functions- all of which contribute to disease pathogenesis. The development of ribosome profiling techniques along with mass spectrometry-based proteomics, mRNA sequencing and single-cell approaches have opened new avenues for detecting diseases related to translation errors. Importantly, we highlight recent advances in therapies targeting translation-related disorders and their potential applications in neurodegenerative diseases, cancer, infectious diseases, and cardiovascular diseases. Moreover, the growing interest lies in targeted therapies aimed at restoring precise control over translation in diseased cells is discussed. In conclusion, this comprehensive review underscores the critical role of protein translation in disease and its potential as a therapeutic target. Advancements in understanding the molecular mechanisms of protein translation deregulation, coupled with the development of targeted therapies, offer promising avenues for improving disease outcomes in various human diseases. Additionally, it will unlock doors to the possibility of precision medicine by offering personalized therapies and a deeper understanding of the molecular underpinnings of diseases in the future.

Reactive oxygen species in biological systems: Pathways, associated diseases, and potential inhibitors-A review

Reactive oxygen species (ROS) are produced under normal physiological conditions and may have beneficial and harmful effects on biological systems. ROS are involved in many physiological processes such as differentiation, proliferation, necrosis, autophagy, and apoptosis by acting as signaling molecules or regulators of transcription factors. In this case, maintaining proper cellular ROS levels is known as redox homeostasis. Oxidative stress occurs because of the imbalance between the production of ROS and antioxidant defenses. Sources of ROS include the mitochondria, auto-oxidation of glucose, and enzymatic pathways such as nicotinamide adenine dinucleotide phosphate reduced (NAD[P]H) oxidase. The possible ROS pathways are NF-κB, MAPKs, PI3K-Akt, and the Keap1-Nrf2-ARE signaling pathway. This review covers the literature pertaining to the possible ROS pathways and strategies to inhibit them. Additionally, this review summarizes the literature related to finding ROS inhibitors.

Exploring the therapeutic potential of natural compounds for Alzheimer's disease: Mechanisms of action and pharmacological properties

Alzheimer's Disease (AD) is a global public health priority characterized by high mortality rates in adults and an increasing prevalence in aging populations worldwide. Despite significant advancements in comprehending the pathogenesis of AD since its initial report in 1907, there remains a lack of effective curative or preventive measures for the disease. In recent years, natural compounds sourced from diverse origins have garnered considerable attention as potential therapeutic agents for AD, owing to their anti-inflammatory, antioxidant, and neuroprotective properties. This review aims to consolidate the therapeutic effects of natural compounds on AD, specifically targeting the reduction of β-amyloid (Aβ) overproduction, anti-apoptosis, autophagy, neuroinflammation, oxidative stress, endoplasmic reticulum (ER) stress, and mitochondrial dysfunction. Notably, the identified compounds exhibiting these effects predominantly originate from plants. This review provides valuable insights into the potential of natural compounds as a reservoir of novel therapeutic agents for AD, thereby stimulating further research and contributing to the development of efficacious treatments for this devastating disease.

Targeting Protein Aggregates with Natural Products: An Optional Strategy for Neurodegenerative Diseases

Protein aggregation is one of the hallmarks of aging and aging-related diseases, especially for the neurodegenerative diseases (NDs) such as Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), Amyotrophic lateral sclerosis (ALS), and others. In these diseases, many pathogenic proteins, such as amyloid-β, tau, α-Syn, Htt, and FUS, form aggregates that disrupt the normal physiological function of cells and lead to associated neuronal lesions. Protein aggregates in NDs are widely recognized as one of the important targets for the treatment of these diseases. Natural products, with their diverse biological activities and rich medical history, represent a great treasure trove for the development of therapeutic strategies to combat disease. A number of in vitro and in vivo studies have shown that natural products, by virtue of their complex molecular scaffolds that specifically bind to pathogenic proteins and their aggregates, can inhibit the formation of aggregates, disrupt the structure of aggregates and destabilize them, thereby alleviating conditions associated with NDs. Here, we systematically reviewed studies using natural products to improve disease-related symptoms by reducing or inhibiting the formation of five pathogenic protein aggregates associated with NDs. This information should provide valuable insights into new directions and ideas for the treatment of neurodegenerative diseases.

The processing methods, phytochemistry and pharmacology of Gastrodia elata Bl.: A comprehensive review

ETHNOPHARMACOLOGICAL RELEVANCE

Gastrodia elata Bl. (GE) is one of the rare Chinese medicinal materials with a long history of medicine and cooking. It consists of a variety of chemical components, including aromatic compounds, organic acids and esters, steroids, saccharides and their glycosides, etc., which has medicinal and edible value, and is widely used in various diseases, such as infantile convulsions, epilepsy, tetanus, headache, dizziness, limb numbness, rheumatism and arthralgia. It is also commonly used in health care products and cosmetics. Thus, its chemical composition and pharmacological activity have attracted more and more attention from the scientific community.

AIM

In this review, the processing methods, phytochemistry and pharmacological activities of GE were comprehensively and systematically summarized, which provides a valuable reference for researchers the rational of GE.

MATERIALS AND METHODS

A comprehensive search of published literature and classic books from 1958 to 2023 was conducted using online bibliographic databases PubMed, Google Scholar, ACS, Science Direct Database, CNKI and others to identify original research related to GE, its processing methods, active ingredients and pharmacological activities.

RESULTS

GE is traditionally used to treat infantile convulsion, epilepsy, tetanus, headache, dizziness, limb numbness, rheumatism and arthralgia. To date, more than 435 chemical constituents were identified from GE including 276 chemical constituents, 72 volatile components and 87 synthetic compounds, which are the primary bioactive compounds. In addition, there are other biological components, such as organic acids and esters, steroids and adenosines. These extracts have nervous system and cardiovascular and cerebrovascular system activities such as sedative-hypnotic, anticonvulsant, antiepileptic, neuron protection and regeneration, analgesia, antidepressant, antihypertensive, antidiabetic, antiplatelet aggregation, anti-inflammatory, etc. CONCLUSION: This review summarizes the processing methods, chemical composition, pharmacological activities, and molecular mechanism of GE over the last 66 years, which provides a valuable reference for researchers to understand its research status and applications.

Protective effect of Gastrodia elata Blume in a Caenorhabditis elegans model of Alzheimer's disease based on network pharmacology

The aim of the present study was to investigate the protective effect of Gastrodia elata Blume (GEB) against Caenorhabditis elegans (C. elegans) in Alzheimer's disease (AD) through network pharmacology. Firstly, the active constituents of GEB through ETCM and BATMAN-TCM databases were collected and its potential AD-related targets in Swiss Target Prediction were predicted. The potential targets related to AD were collected from the GeneCards, OMIM, CTD and DisGeNET databases, and the differential genes (DEGs) between the normal population and the AD patient population in GSE5281 chip of the Gene Expression Omnibus database were collected at the same time. The intersection of the three targets yielded 59 key targets of GEB for the treatment of AD. The drug-active ingredient-target-AD network diagram was constructed and visualized with Cytoscape software to obtain the core components. Subsequently, protein-protein interaction analysis (PPI) was performed on 59 key targets through STRING database, and Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses was performed on 59 key targets. Finally, molecular docking was conducted between core components and core targets using AutoDock software, and the C. elegans AD model was used for experimental verification to explore the regulatory paralysis effect of core components on the C. elegans model, β-amyloid (Aβ) plaque deposition, and quantitative polymerase chain reaction verification of the regulatory effect of components on targets. The GEB components 4,4'-dihydroxydiphenyl methane (DM) and protocatechuic aldehyde (PA) were found to be most strongly associated with AD, and five core targets were identified in the PPI network, including GAPDH, EP300, HSP90AB1, KDM6B, and CREBBP. In addition to GAPDH, the other four targets were successfully docked with DM and PA using AutoDock software. Compared with the control group, 0.5 mM DM and 0.25 mM PA significantly delayed C. elegans paralysis (P<0.01), and inhibited the aggregation of Aβ plaques in C. elegans. Both DM and PA could upregulate the expression level of core target gene HSP90AB1 (P<0.01), and DM upregulated the expression of KDM6B (P<0.01), suggesting that DM and PA may be potential active components of GEB in the treatment of AD.

Gastrodin ameliorates the lipopolysaccharide-induced neuroinflammation in mice by downregulating miR-107-3p

Background: Neuroinflammation plays a pivotal role in the pathogenesis of Central Nervous System (CNS) diseases. The phenolic glucoside gastrodin (GAS), has been known to treat CNS disorders by exerting anti-inflammatory activities. Our aim was to investigate the potential neuroprotective mechanisms of GAS on lipopolysaccharide (LPS)-induced mice. Methods: Male C57BL/6J mice were treated by LPS, before which GAS was adminisrated. The behavior tests such as forced swim test, tail suspension test, and elevated plus maze were performed to evaluate depressive-anxiety-like behaviors. A high-throughput sequencing (HTS) analysis was performed to screen out distinctive miRNAs which were validated using quantitative real-time PCR. Then, miRNA agomir or NC was injected stereotaxically into hippocampus of mice to explore the role of miRNA on GAS in response to LPS. Furthermore, Immunofluorescence and the hematoxylin and eosin (H&E) staining were employed to observe the cellular morphology. The protein levels of pro-inflammatory factors were evaluated by western blot. Finally, the target mRNA of miRNA was predicted using bioinformatics analysis. GO and KEGG enrichment analyses were conducted to clarify the potential function of target protein, which were visualized by bubble charts. Results: The behavioral data showed that mice in the LPS group had obvious depressive-anxiety-like behaviors, and 100 mg/kg GAS could improve these behavioral changes and alleviate the levels of pro-inflammatory cytokines in the hippocampus when mice were exposed to LPS for 6 h. Meanwhile, LPS-induced microglia and astrocyte activation in the CA1, CA2, CA3, and DG regions of the hippocampus were also reversed by GAS. Furthermore, miR-107-3p were screened out and verified for GAS in response to LPS. Importantly, miR-107-3p overexpression negatively abrogated the neuroprotective effects of GAS. Moreover, KPNA1 might be the target molecular of miR-107-3p. KPNA1 might regulate 12 neuroinflammation-related genes, which were mainly involved in cytokine-mediated signaling pathway. Conclusion: These results suggested that GAS might alleviate the LPS-induced neuroinflammation and depressive-anxiety-like behaviors in mice by downregulating miR-107-3p and upregulating the downstream target KPNA1. The indicates miR-107-3p may provide a new strategy for the treatment of CNS diseases.

Post treatment with Gastrodin suppresses oxidative stress and attenuates motor disorders following 6-OHDA induced Parkinson disease

BACKGROUND & OBJECTIVE

Researchers are currently trying to find new therapies with better symptomatic activity and fewer side effects to manage Parkinson's disease (PD). Although the protective effect of pre-treatment by Gastrodin (Gst) on a PD model has been evaluated, in the current experimental study, we investigated the symptomatic therapeutic effects of Gst microinjection in the same PD model but in the post-parkinsonism induction condition.

METHODS

Parkinsonism was induced by unilateral infusion of 6- hydroxydopamine (6-OHDA; 8 μg/ 2 μl/ rat) into the central region of the substantia nigra pars compacta (SNc). After the recovery period and confirmation of parkinsonism, daily Gst treatment in three doses (20, 40, 80 µg/ 2 µ/ rat, continued for ten days with motor monitoring by bar test and rotarod examinations. Moreover, lipid peroxidation and myeloperoxidase activity were evaluated.

RESULTS

In this model of 6-OHDA-induced parkinsonism, Gst treatment in all three doses showed a dose dependent symptomatic improvement in motor imbalance (P < 0.001) catalepsy (P < 0.001), decreased lipid peroxidation (P < 0.001) and SNc myeloperoxidase activity (P < 0.001) CONCLUSIONS: 6-OHDA induced parkinsonism symptomatically improved behaviorally with Gst post-induction treatment along with decreased markers of oxidative stress and microglial activation. We suggest that this agent is a candidate for symptomatic treatment of human PD.

Exploring the Therapeutic Potential of Phytochemicals in Alzheimer’s Disease: Focus on Polyphenols and Monoterpenes

Alzheimer’s disease (AD) is a chronic, complex neurodegenerative disorder mainly characterized by the irreversible loss of memory and cognitive functions. Different hypotheses have been proposed thus far to explain the etiology of this devastating disorder, including those centered on the Amyloid-β (Aβ) peptide aggregation, Tau hyperphosphorylation, neuroinflammation and oxidative stress. Nonetheless, the therapeutic strategies conceived thus far to treat AD neurodegeneration have proven unsuccessful, probably due to the use of single-target drugs unable to arrest the progressive deterioration of brain functions. For this reason, the theoretical description of the AD etiology has recently switched from over-emphasizing a single deleterious process to considering AD neurodegeneration as the result of different pathogenic mechanisms and their interplay. Moreover, much relevance has recently been conferred to several comorbidities inducing insulin resistance and brain energy hypometabolism, including diabetes and obesity. As consequence, much interest is currently accorded in AD treatment to a multi-target approach interfering with different pathways at the same time, and to life-style interventions aimed at preventing the modifiable risk-factors strictly associated with aging. In this context, phytochemical compounds are emerging as an enormous source to draw on in the search for multi-target agents completing or assisting the traditional pharmacological medicine. Intriguingly, many plant-derived compounds have proven their efficacy in counteracting several pathogenic processes such as the Aβ aggregation, neuroinflammation, oxidative stress and insulin resistance. Many strategies have also been conceived to overcome the limitations of some promising phytochemicals related to their poor pharmacokinetic profiles, including nanotechnology and synthetic routes. Considering the emerging therapeutic potential of natural medicine, the aim of the present review is therefore to highlight the most promising phytochemical compounds belonging to two major classes, polyphenols and monoterpenes, and to report the main findings about their mechanisms of action relating to the AD pathogenesis.

Gastrodin and Vascular Dementia: Advances and Current Perspectives

Gastrodia elata, a traditional Chinese medicine, has been widely used since ancient times to treat diseases such as dizziness, epilepsy, stroke, and memory loss. Gastrodin, one of the active components of Gastrodia elata, has been used in the treatment of migraine, epilepsy, Parkinson's disease, dementia, and depression in recent years. It can improve cognitive function and related neuropsychiatric symptoms through various effects and is considered as a promising treatment for dementia. Vascular dementia is a kind of severe cognitive impairment syndrome caused by vascular factors, and it is the dementia syndrome with the largest number of patients besides Alzheimer's disease. Although there is still a lack of evidence-based explorations, the paper reviewed the mechanism and methods of gastrodin in the treatment of vascular dementia, providing a reference for clinical therapy.

Treatment Combining Focused Ultrasound with Gastrodin Alleviates Memory Deficit and Neuropathology in an Alzheimer's Disease-Like Experimental Mouse Model

Alzheimer's disease (AD) is the most common type of dementia but lacks effective treatment at present. Gastrodin (GAS) is a phenolic glycoside extracted from the traditional Chinese herb-Gastrodia elata-and has been reported as a potential therapeutic agent for AD. However, its efficiency is reduced for AD patients due to its limited BBB permeability. Studies have demonstrated the feasibility of opening the blood-brain barrier (BBB) via focused ultrasound (FUS) to overcome the obstacles preventing medicines from blood flow into the brain tissue. We explored the therapeutic potential of FUS-mediated BBB opening combined with GAS in an AD-like mouse model induced by unilateral intracerebroventricular (ICV) injection of Aβ 1-42. Mice were divided into 5 groups: control, untreated, GAS, FUS and FUS+GAS. Combined treatment (FUS+GAS) rather than single intervention (GAS or FUS) alleviated memory deficit and neuropathology of AD-like mice. The time that mice spent in the novel arm was prolonged in the Y-maze test after 15-day intervention, and the waste-cleaning effect was remarkably increased. Contents of Aβ, tau, and P-tau in the observed (also the targeted) hippocampus were reduced. BDNF, synaptophysin (SYN), and PSD-95 were upregulated in the combined group. Overall, our results demonstrate that FUS-mediated BBB opening combined with GAS injection exerts the potential to alleviate memory deficit and neuropathology in the AD-like experimental mouse model, which may be a novel strategy for AD treatment.

Activation of GPR55 attenuates cognitive impairment and neurotoxicity in a mouse model of Alzheimer's disease induced by Aβ1-42 through inhibiting RhoA/ROCK2 pathway

The accumulation of amyloid-β (Aβ) peptides in the brain is considered to be the initial event in the Alzheimer's disease (AD). Neurotoxicity mediated by Aβ has been demonstrated to damage the cognitive function. In the present study, we sought to determine the effects of O-1602, a specific G-protein coupled receptor 55 (GPR55) agonist, on the impairment of learning and memory induced by intracerebroventricular (i.c.v.) of Aβ_1-42 (400 pmol/mouse) in mice. Our results showed that i.c.v. injection of aggregated Aβ_1-42 into the brain of mice resulted in cognitive impairment and neurotoxicity. In contrast, O-1602 (2.0 or 4.0 μg/mouse, i.c.v.) can improve memory impairment induced by Aβ_1-42 in the Morris water maze (MWM), and novel object recognition (NOR) tests. Besides, we found that O-1602 reduced the activity of β-secretase 1 (BACE1) and the level of soluble Aβ_1-42 in the hippocampus and frontal cortex. Importantly, O-1602 treatment reversed Aβ_1-42-induced GPR55 down-regulation, decreased pro-inflammatory cytokines, and the level of malondialdehyde (MDA), increased the levels of glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT), as well as suppressed apoptosis as indicated by decreased TUNEL-positive cells, and increased the ratio of Bcl-2/Bax. O-1602 treatment also pronouncedly ameliorated synaptic dysfunction by promoting the upregulation of PSD-95 and synaptophysin (SYN) proteins. Moreover, O-1602 concurrently down regulated the protein levels of RhoA, and ROCK2, the critical proteins in the RhoA/ROCK2 pathway. This study indicates that O-1602 may reverse Aβ_1-42-induced cognitive impairment and neurotoxicity in mice by inhibiting RhoA/ROCK2 pathway. Taken together, these findings suggest that GPR55 could be a novel and promising target for the treatment of AD.

Gastrodia elata blume ameliorates circadian rhythm disorder-induced mice memory impairment

Circadian rhythm disorder (CRD) in space flight can lead to memory impairment, performance decrements and adverse health outcomes, the main manifestations of which are circadian desynchronization, sleep loss and insomnia. Sleep deprivation (SD) provide the means to evaluate these effects and the risks associated with CRD on ground. Gastrodia elata Blume (GEB) has beneficial effects on the treatment of sleep disturbances and memory loss. Fresh GEB (FG), an unprocessed raw tuber of GEB, has been used as functional health food in Asian countries for a long time. However, the research report of FG to ameliorate memory impairment caused by insomnia or lack of sleep is meager. In this study, ICR male mice were sleep-deprived continuously and water extract of FG (WFG) was orally administrated (3 and 9 g/kg/d, i.g) during the SD process lasted for 25 days, except control and model groups gavage administration with water, positive control group with modafinil (MOD, 0.1 g/kg/d, i.g). We studied the effect of WFG on CRD-induced learning and memory impairment using a set of behavioral analyses including the object location recognition test (OLRT), novel object recognition test (NORT), and the passive avoidance test (PAT). In addition, oxidative stress parameters were assessed by measuring the malondialdehyde (MDA) and superoxide dismutase (SOD) reactivity in serum and hippocampus. Our results revealed that SD decreased discrimination index (DI) in OLRT and NORT, with shorter latency into the dark chamber in PAT. Both WFG and MOD treatment can reverse these changes (P < 0.05). We concluded that WFG treatment improve CRD-induced learning and memory impairment and oxidative stress damage which makes FG a promising candidate as herbal health product of memory decline in CRD.

Ferroptosis as a mechanism of neurodegeneration in Alzheimer's disease

Alzheimer's disease (AD) is the most prevalent form of dementia, with complex pathophysiology that is not fully understood. While β-amyloid plaque and neurofibrillary tangles define the pathology of the disease, the mechanism of neurodegeneration is uncertain. Ferroptosis is an iron-mediated programmed cell death mechanism characterised by phospholipid peroxidation that has been observed in clinical AD samples. This review will outline the growing molecular and clinical evidence implicating ferroptosis in the pathogenesis of AD, with implications for disease-modifying therapies.

Therapeutic Effects of Natural Compounds and Small Molecule Inhibitors Targeting Endoplasmic Reticulum Stress in Alzheimer's Disease

Alzheimer’s disease (AD) is the most common neurodegenerative disease, characterized by progressive cognitive impairment and memory loss. So far, the pathogenesis of AD has not been fully understood. Research have shown that endoplasmic reticulum (ER) stress and unfolded protein response (UPR) participate in the occurrence and development of AD. Furthermore, various studies, both in vivo and in vitro, have shown that targeting ER stress and ER stress-mediated apoptosis contribute to the recovery of AD. Thus, targeting ER stress and ER stress-mediated apoptosis may be effective for treating AD. In this review, the molecular mechanism of ER stress and ER stress-mediated apoptosis, as well as the therapeutic effects of some natural compounds and small molecule inhibitors targeting ER stress and ER stress-mediated apoptosis in AD will be introduced.

Oxidative Stress and Beta Amyloid in Alzheimer's Disease. Which Comes First: The Chicken or the Egg?

The pathogenesis of Alzheimer's disease involves β amyloid (Aβ) accumulation known to induce synaptic dysfunction and neurodegeneration. The brain's vulnerability to oxidative stress (OS) is considered a crucial detrimental factor in Alzheimer's disease. OS and Aβ are linked to each other because Aβ induces OS, and OS increases the Aβ deposition. Thus, the answer to the question "which comes first: the chicken or the egg?" remains extremely difficult. In any case, the evidence for the primary occurrence of oxidative stress in AD is attractive. Thus, evidence indicates that a long period of gradual oxidative damage accumulation precedes and results in the appearance of clinical and pathological AD symptoms, including Aβ deposition, neurofibrillary tangle formation, metabolic dysfunction, and cognitive decline. Moreover, oxidative stress plays a crucial role in the pathogenesis of many risk factors for AD. Alzheimer's disease begins many years before its symptoms, and antioxidant treatment can be an important therapeutic target for attacking the disease.

Gastrodin extends the lifespan and protects against neurodegeneration in the Drosophila PINK1 model of Parkinson's disease

Gastrodin is the main bioactive ingredient of a famous Chinese herb Rhizoma Gastrodiae. Many studies have reported that gastrodin has antioxidative and neuroprotective effects, although its effect on longevity and the mechanism of neuroprotection have not been well studied. Here, we use Drosophila melanogaster as a model to investigate the longevity and neuroprotective effects of gastrodin. Gastrodin significantly extended the lifespan, increased the climbing ability, enhanced the resistance to oxidative stress, increased the enzyme activities of superoxide dismutase (SOD) and catalase (CAT), and promoted the expression of anti-oxidative genes in old flies. The food intake, reproduction and starvation resistance were not affected in flies treated with gastrodin. Moreover, gastrodin delayed the onset of Parkinson-like phenotypes in Pink1^B9 mutant flies, including the prolongation of the lifespan, rescue of the climbing ability, rescue of the progressive loss of a cluster of dopaminergic neurons in the protocerebral posterial lateral 1 region, and increase of the dopamine content in the brain. Gastrodin did not ameliorate the tau-induced neurobehavioral deficits in the fly AD model of taupathy. Together, these results indicate that gastrodin could prolong the lifespan by regulating the antioxidant ability, and protect against neurodegeneration in the Pink1^B9 model of PD. This suggests that gastrodin can be considered as an ideal therapeutic candidate for drug development towards anti-aging.

Gallic Acid Prevents the Oxidative and Endoplasmic Reticulum Stresses in the Hippocampus of Adult-Onset Hypothyroid Rats

Thyroid hormone is essential for hippocampal redox environment and neuronal viability in adulthood, where its deficiency causes hypothyroidism related to oxidative and endoplasmic reticulum stresses in the hippocampus, resulting in neuronal death. One option of treatment is antioxidants; however, they must be transported across the blood-brain barrier. Gallic acid is a polyphenol that meets these criteria. Thus, this study aimed to prove that the neuroprotective mechanism of GA is associated with the prevention of oxidative and endoplasmic reticulum stresses in the hippocampus of adult-onset hypothyroid rats. Male Wistar rats were divided into euthyroid (n = 20) and hypothyroid groups (n = 20). Thyroidectomy with parathyroid gland reimplementation caused hypothyroidism. Each group was subdivided into two: vehicle and 50 mg/kg/d of gallic acid. 3 weeks after thyroidectomy, six animals of each group were euthanized, and the hippocampus was dissected to evaluate oxidative and endoplasmic reticulum stress markers. The rest of the animals were euthanized after 4 weeks of treatment for histological analysis of the hippocampus. The results showed that hypothyroidism increased lipid peroxidation, reactive oxygen species, and nitrites; it also increased endoplasmic reticulum stress by activating the inositol-requiring enzyme-1α (IRE1α) pathway, the protein kinase RNA-like endoplasmic reticulum kinase (PERK) and activated transcription factor 6α (ATF6α) pathways associated with a proapoptotic state that culminates in hippocampal neuronal damage. Meanwhile, the hypothyroid rat treated with gallic acid reduced oxidative stress and increased endoplasmic reticulum-associated degradation (ERAD) through IRE1α and ATF6. Also, the gallic acid treatment prevented the Bax/BCl2 ratio from increasing and the overexpression of p53 and caspase 12. This treatment in hypothyroid animals was associated with the neuronal protection observed in the hippocampus. In conclusion, gallic acid prevents hypothyroidism-induced hippocampal damage associated with oxidative and endoplasmic reticulum stresses.

The Potential Role of Protein Kinase R as a Regulator of Age-Related Neurodegeneration

There is a growing evidence describing a decline in adaptive homeostasis in aging-related diseases affecting the central nervous system (CNS), many of which are characterized by the appearance of non-native protein aggregates. One signaling pathway that allows cell adaptation is the integrated stress response (ISR), which senses stress stimuli through four kinases. ISR activation promotes translational arrest through the phosphorylation of the eukaryotic translation initiation factor 2 alpha (eIF2α) and the induction of a gene expression program to restore cellular homeostasis. However, depending on the stimulus, ISR can also induce cell death. One of the ISR sensors is the double-stranded RNA-dependent protein kinase [protein kinase R (PKR)], initially described as a viral infection sensor, and now a growing evidence supports a role for PKR on CNS physiology. PKR has been largely involved in the Alzheimer’s disease (AD) pathological process. Here, we reviewed the antecedents supporting the role of PKR on the efficiency of synaptic transmission and cognition. Then, we review PKR’s contribution to AD and discuss the possible participation of PKR as a player in the neurodegenerative process involved in aging-related pathologies affecting the CNS.

Gastrodia elata Blume (Tianma): Hope for Brain Aging and Dementia

Since aging-related diseases, including dementia, represent major public health threats to our society, physician-scientists must develop innovative, interdisciplinary strategies to open new avenues for development of alternative therapies. One such novel approach may lie in traditional Chinese medicine (TCM). Gastrodia elata Blume (G. elata, tianma) is a TCM frequently used for treatment of cerebrocardiovascular diseases (CCVDs). Recent studies of G. elata-based treatment modalities, which have investigated its pharmacologically relevant activity, potential efficacy, and safety, have employed G. elata in well-characterized, aging-related disease models, with a focus on models of aging-related dementia, such as Alzheimer's disease (AD). Here, I examine results from previous studies of G. elata, as well as related herbal preparations and pure natural products, as prophylaxis and remedies for aging-related CCVDs and dementia. Concluding, data suggest that tianma treatment may be used as a promising complementary therapy for AD.

Pathogenesis and promising therapeutics of Alzheimer disease through eIF2α pathway and correspondent kinases

Eukaryotic initiation factor 2 (eIF2α) pathway is overactivated in Alzheimer disease and is probably associated with synaptic and memory deficiencies. EIF2α protein is principally in charge of the regulation of protein synthesis in eukaryotic cells. Four kinases responsible for eIF2α phosphorylation at ser-51 are: General control non-derepressible-2 kinase (GCN2), double-stranded RNA-activated protein kinase (PKR), PKR-like endoplasmic reticulum kinase (PERK), and heme-regulated inhibitor kinase (HRI) are the four kinases. They lead to reduced levels of general translation and paradoxical increase of stress-responsive mRNAs expression including the B-secretase (BACE1) and the transcriptional modulator activating transcription factor 4 (ATF4), which in turn accelerates the beta-amyloidogenesis, tau phosphorylation, proapoptotic pathway induction and autophagy elements formation leading to the main pathological hallmarks of AD. Findings suggest that genetic or pharmacological inhibition of correspondent kinases can restore memory and prevent neurodegeneration. This implies that inhibition of eIF2α phosphorylation through respondent kinases is indeed a feasible prospect of clinical application. This review discusses recent therapeutic approaches targeting eIF2α pathway and provides an overview of the links between correspondent kinases overactivation with neurodegeneration in AD.

Primer on the Pathogenesis of Severe COVID-19: Part One

In Part One of this exploration of the pathogenesis of coronavirus disease (COVID-19), the author will evaluate the viral and cellular immunological basis for the condition. The virus demonstrates a remarkable capability not just to evade, but to exploit host immune characteristics to perpetuate viral replication. In this regard, severe acute respiratory syndrome (SARS)/severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) disables most antiviral mechanisms, including the early interferon response, and avoids detection to permit unimpeded viral multiplication. Consequently, antigen-presenting cells fail to adequately stimulate the T-cell receptor. As a consequence, T-cell p53 remains highly expressed, which in turn disables an adequate effector T-cell response. Replicating SARS-CoV-2 double-strand RNA robustly activates protein kinase R (PKR)/PKR-like endoplasmic reticulum kinase (PERK). While the virus is grossly invulnerable to its antiviral effects, PKR is crucial for effecting the cytokine milieu in COVID-19. PERK is a component of the unfolded protein response, which eventuates in autophagy. SARS virions use double-membrane vesicles and adapt PERK signalling not only to avoid autophagy, but to facilitate replication. Viral activation of PKR/PERK is mutually exclusive to NLRP3 stimulation. The NLRP3 pathway elaborates IL-1β. This is chiefly a feature of paediatric SARS/SARS-CoV-2 cases. The difficulties encountered in predicting outcome and forging effective therapeutics speaks to the breadth of complexity of the immunopathogenesis of this virus.

Plant-Derived Natural Biomolecule Picein Attenuates Menadione Induced Oxidative Stress on Neuroblastoma Cell Mitochondria

Several bioactive compounds are in use for the treatment of neurodegenerative disorders, such as Alzheimer’s and Parkinson’s disease. Historically, willow (salix sp.) bark has been an important source of salisylic acid and other natural compounds with anti-inflammatory, antipyretic and analgesic properties. Among these, picein isolated from hot water extract of willow bark, has been found to act as a natural secondary metabolite antioxidant. The aim of this study was to investigate the unrevealed pharmacological action of picein. In silico studies were utilized to direct the investigation towards the neuroprotection abilities of picein. Our in vitro studies demonstrate the neuroprotective properties of picein by blocking the oxidative stress effects, induced by free radical generator 2-methyl-1,4-naphthoquinone (menadione, MQ), in neuroblastoma SH-SY5Y cells. Several oxidative stress-related parameters were evaluated to measure the protection for mitochondrial integrity, such as mitochondrial superoxide production, mitochondrial activity (MTT), reactive oxygen species (ROS) and live-cell imaging. A significant increase in the ROS level and mitochondrial superoxide production were measured after MQ treatment, however, a subsequent treatment with picein was able to mitigate this effect by decreasing their levels. Additionally, the mitochondrial activity was significantly decreased by MQ exposure, but a follow-up treatment with picein recovered the normal metabolic activity. In conclusion, the presented results demonstrate that picein can significantly reduce the level of MQ-induced oxidative stress on mitochondria, and thereby plays a role as a potent neuroprotectant.

A Novel Compound YS-5-23 Exhibits Neuroprotective Effect by Reducing β-Site Amyloid Precursor Protein Cleaving Enzyme 1's Expression and H2O2-Induced Cytotoxicity in SH-SY5Y Cells

The abnormally accumulated amyloid-β (Aβ) and oxidative stress contribute to the initiation and progression of Alzheimer's disease (AD). β-site amyloid precursor protein cleaving enzyme 1 (BACE1) is the rate-limiting enzyme for the production of Aβ. Furthermore, Aβ was reported to increase oxidative stress; then the overproduced oxidative stress continues to increase the expression and activity of BACE1. Consequently, inhibition of both BACE1 and oxidative stress is a better strategy for AD therapy compared with those one-target treatment methods. In the present study, our novel small molecule YS-5-23 was proved to possess both of the activities. Specifically, we found that YS-5-23 reduces BACE1's expression in both SH-SY5Y and Swedish mutated amyloid precursor protein (APP) overexpressed HEK293 cells, and it can also suppress BACE1's expression induced by H₂O₂. Moreover, YS-5-23 decreases H₂O₂-induced cytotoxicity including alleviating H₂O₂-induced apoptosis and loss of mitochondria membrane potential (MMP) because it attenuates the reactive oxygen species (ROS) level elevated by H₂O₂. Meanwhile, PI3K/Akt signaling pathway is involved in the anti-H₂O₂ and BACE1 inhibition effect of YS-5-23. Our findings indicate that YS-5-23 may develop as a drug candidate in the prevention and treatment of AD.

The PERK-Dependent Molecular Mechanisms as a Novel Therapeutic Target for Neurodegenerative Diseases

Higher prevalence of neurodegenerative diseases is strictly connected with progressive aging of the world population. Interestingly, a broad range of age-related, neurodegenerative diseases is characterized by a common pathological mechanism-accumulation of misfolded and unfolded proteins within the cells. Under certain circumstances, such protein aggregates may evoke endoplasmic reticulum (ER) stress conditions and subsequent activation of the unfolded protein response (UPR) signaling pathways via the protein kinase RNA-like endoplasmic reticulum kinase (PERK)-dependent manner. Under mild to moderate ER stress, UPR has a pro-adaptive role. However, severe or long-termed ER stress conditions directly evoke shift of the UPR toward its pro-apoptotic branch, which is considered to be a possible cause of neurodegeneration. To this day, there is no effective cure for Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), or prion disease. Currently available treatment approaches for these diseases are only symptomatic and cannot affect the disease progression. Treatment strategies, currently under detailed research, include inhibition of the PERK-dependent UPR signaling branches. The newest data have reported that the use of small-molecule inhibitors of the PERK-mediated signaling branches may contribute to the development of a novel, ground-breaking therapeutic approach for neurodegeneration. In this review, we critically describe all the aspects associated with such targeted therapy against neurodegenerative proteopathies.

Metabolite Profiling and Distribution of Militarine in Rats Using UPLC-Q-TOF-MS/MS

Militarine, a natural glucosyloxybenzyl 2-isobutylmalate, isolated from Bletilla striata, was reported with a prominent neuroprotective effect recently. The limited information on the metabolism of militarine impedes comprehension of its biological actions and pharmacology. This study aimed to investigate the metabolite profile and the distribution of militarine in vivo, which help to clarify the action mechanism further. A total of 71 metabolites (57 new metabolites) in rats were identified with a systematic method by ultra-high-performance liquid chromatography combined with quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF-MS/MS). The proposed metabolic pathways of militarine include hydrolyzation, oxidation, glycosylation, esterification, sulfation, glucuronidation and glycine conjugation. Militarine and its metabolites were distributed extensively in the treated rats. Notably, six metabolites of militarine were identified in cerebrospinal fluid (CSF), which were highly consistent with the metabolites after oral administration of gastrodin in rats. Among the metabolites in CSF, five of them were not reported before. It is the first systematic metabolic study of militarine in vivo, which is very helpful for better comprehension of the functions and the central nervous system (CNS) bioactivities of militarine. The findings will also provide an essential reference for the metabolism of other glucosylated benzyl esters of succinic, malic, tartaric and citric acids.

Therapeutic Effects of Natural Drugs on Alzheimer's Disease

Alzheimer disease (AD) is characterized as a chronic neurodegenerative disease associated with aging. The clinical manifestations of AD include latent episodes of memory and cognitive impairment, psychiatric symptoms and behavioral disorders, as well as limited activities in daily life. In developed countries, AD is now acknowledged as the third leading cause of death, following cardiovascular disease and cancer. The pathogenesis and mechanism of AD remain unclear, although some theories have been proposed to explain AD, such as the theory of β-amyloid, the theory of the abnormal metabolism of tau protein, the theory of free radical damage, the theory of the inflammatory response, the theory of cholinergic damage, etc. Effective methods to predict, prevent or reverse AD are unavailable, and thus the development of new, efficient therapeutic drugs has become a current research hot spot worldwide. The isolation and extraction of active components from natural drugs have great potential in treating AD. These drugs possess the advantages of multiple targets in multiple pathways, fewer side effects and a long duration of curative effects. This article summaries the latest research progress regarding the mechanisms of natural drugs in the treatment of AD, providing a review of the literature and a theoretical basis for improving the clinical treatment of AD.

Botanicals as modulators of depression and mechanisms involved

Depression is the most disastrous mood disorder affecting the health of individuals. Conventional treatments with chemical compounds for depression have limitations, while herbal medicine has unique therapeutic effects. This paper introduces the pharmacological basis and biological mechanisms underlying the botanical antidepressants over the past 5 years. Based upon the specific therapeutic targets or mechanisms, we analyzed the pathological roles of monoamine neurotransmitters, the hypothalamic-pituitary-adrenal axis, inflammation, oxidative stress, synaptic plasticity performed in antidepressant of the botanicals. In addition, gut flora and neurogenesis were also preferentially discussed as treatment approaches. Based on the complex pathogenesis of depression, we suggested that mixed use of botanicals, namely prescription would be more suitable for treatment of depression. In addition, neural circuit affected by botanicals or active components should also attract attention as the botanicals have potential to be developed into fast-acting antidepressants. Finally, gut flora might be a new systemic target for the treatment of depression by botanicals. This review would strength botanical medicine as the antidepressant and also provides an overview of the potential mechanisms involved.

BACE1 Translation: At the Crossroads Between Alzheimer's Disease Neurodegeneration and Memory Consolidation

 Human life unfolds not only in time and space, but also in the recollection and interweaving of memories. Therefore, individual human identity depends fully on a proper access to the autobiographical memory. Such access is hindered under pathological conditions such as Alzheimer’s disease, which affects millions of people worldwide. Unfortunately, no effective cure exists to prevent this disorder, the impact of which will rise alarmingly within the next decades. While Alzheimer’s disease is largely considered to be the outcome of amyloid-β (Aβ) peptide accumulation in the brain, conceiving this complex disorder strictly as the result of Aβ-neurotoxicity is perhaps a too straight-line simplification. Instead, complementary to this view, the tableau of molecular disarrangements in the Alzheimer’s disease brain may be reflecting, at least in part, a loss of function phenotype in memory processing. Here we take BACE1 translation and degradation as a gateway to study molecular mechanisms putatively involved in the transition between memory and neurodegeneration. BACE1 participates in the excision of Aβ-peptide from its precursor holoprotein, but plays a role in synaptic plasticity too. Its translation is governed by eIF2α phosphorylation: a hub integrating cellular responses to stress, but also a critical switch in memory consolidation. Paralleling these dualities, the eIF2α-kinase HRI has been shown to be a nitric oxide-dependent physiological activator of hippocampal BACE1 translation. Finally, beholding BACE1 as a representative protease active in the CNS, we venture a new perspective on the cellular basis of memory, which may incorporate neurodegeneration in itself as a drift in memory consolidating systems.

Illumination with 630 nm Red Light Reduces Oxidative Stress and Restores Memory by Photo-Activating Catalase and Formaldehyde Dehydrogenase in SAMP8 Mice

AIMS

Pharmacological treatments for Alzheimer's disease (AD) have not resulted in desirable clinical efficacy over 100 years. Hydrogen peroxide (H₂O₂), a reactive and the most stable compound of reactive oxygen species, contributes to oxidative stress in AD patients. In this study, we designed a medical device to emit red light at 630 ± 15 nm from a light-emitting diode (LED-RL) and investigated whether the LED-RL reduces brain H₂O₂ levels and improves memory in senescence-accelerated prone 8 mouse (SAMP8) model of age-related dementia.

RESULTS

We found that age-associated H₂O₂ directly inhibited formaldehyde dehydrogenase (FDH). FDH inactivity and semicarbazide-sensitive amine oxidase (SSAO) disorder resulted in endogenous formaldehyde (FA) accumulation. Unexpectedly, excess FA, in turn, caused acetylcholine (Ach) deficiency by inhibiting choline acetyltransferase (ChAT) activity in vitro and in vivo. Interestingly, the 630 nm red light can penetrate the skull and the abdomen with light penetration rates of ∼49% and ∼43%, respectively. Illumination with LED-RL markedly activated both catalase and FDH in the brains, cultured cells, and purified protein solutions, all reduced brain H₂O₂ and FA levels and restored brain Ach contents. Consequently, LED-RL not only prevented early-stage memory decline but also rescued late-stage memory deficits in SAMP8 mice.

INNOVATION

We developed a phototherapeutic device with 630 nm red light, and this LED-RL reduced brain H₂O₂ levels and reversed age-related memory disorders.

CONCLUSIONS

The phototherapy of LED-RL has low photo toxicity and high rate of tissue penetration and noninvasively reverses aging-associated cognitive decline. This finding opens a promising opportunity to translate LED-RL into clinical treatment for patients with dementia. Antioxid. Redox Signal. 00, 000-000.

RETRACTED: Gastrodin protects rat cardiomyocytes H9c2 from hypoxia-induced injury by up-regulation of microRNA-21

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief and Author. The journal contacted the authors for their response to the following remark from Dr Elisabeth Bik regarding this paper: ‘This paper belongs to a set of over 400 papers (as per February 2020) that share very similar Western blots with tadpole-like shaped bands, the same background pattern, and striking similarities in title structures, paper layout, bar graph design, and - in a subset - flow cytometry panels. Despite these similarities, these papers are authored by researchers from different departments and institutes, with almost no overlap in authors’. The authors failed to respond to this directly but instead requested the journal to retract the paper on the basis that the data were not represented accurately and new results have shown inconsistency with what has been reported in this paper. The authors apologise for any misconceptions that this paper may have resulted in.

G-Protein-Coupled Receptor 120 Mediates DHA-Induced Apoptosis by Regulating IP3R, ROS and, ER Stress Levels in Cisplatin-Resistant Cancer Cells

The omega-3 fatty acid docosahexaenoic acid (DHA) is known to induce apoptosis and cell cycle arrest via the induction of reactive oxygen species (ROS) production and endoplasmic reticulum (ER) stress in many types of cancers. However, the roles of DHA in drug-resistant cancer cells have not been elucidated. In this study, we investigated the effects of DHA in cisplatin-resistant gastric cancer SNU-601/cis2 cells. DHA was found to induce ROS-dependent apoptosis in these cells. The inositol 1,4,5-triphosphate receptor (IP3R) blocker 2-aminoethyl diphenylboninate (2-APB) reduced DHA-induced ROS production, consequently reducing apoptosis. We also found that G-protein-coupled receptor 120 (GPR120), a receptor of long-chain fatty acids, is expressed in SNU-601/cis2 cells, and the knockdown of GPR120 using specific shRNAs alleviated DHA-mediated ROS production and apoptosis. GPR120 knockdown reduced the expression of ER stress response genes, similar to the case for the pre-treatment of the cells with N-acetyl-L-cysteine (NAC), an ROS scavenger, or 2-APB. Indeed, the knockdown of C/EBP homologous protein (CHOP), a transcription factor that functions under ER stress conditions, markedly reduced DHA-mediated apoptosis, indicating that CHOP plays an essential role in the anti-cancer activity of DHA. These results suggest that GPR120 mediates DHA-induced apoptosis by regulating IP3R, ROS, and ER stress levels in cisplatin-resistant cancer cells, and that GPR120 is an effective chemotherapeutic target for cisplatin resistance.

Acteoside Attenuates Oxidative Stress and Neuronal Apoptosis in Rats with Focal Cerebral Ischemia-Reperfusion Injury

Acteoside (ACT) has been shown to exert antioxidant and neuroprotective effects in neurodegenerative diseases. However, the effect of ACT on cerebral ischemia-reperfusion (I/R) injury is not yet clear. In this study, we found that ACT administration reduced infarct volume and brain edema, and improved neurological deficits, as indicated by the decreased modified neurological severity score. Administration of ACT strikingly reduced oxidative stress, accompanied by decreased levels of reactive oxygen species and malondialdehyde and increased levels of superoxide dismutase and catalase in a rat model of middle cerebral artery occlusion/reperfusion (MCAO/R). Furthermore, ACT administration reduced the number of terminal deoxynucleotidyl transferase uridine 5'-triphosphate (UTP) nick-end labeling-positive cells in the cerebral cortex of ischemic side of MCAO/R rats, accompanied by downregulation of B cell lymphoma 2 (Bcl-2) associated X protein and cleaved caspase-3 proteins and upregulation of Bcl-2 protein. Additionally, ACT treatment inhibited the protein kinase R/eukaryotic initiation factor-2α stress pathway in the brains of MCAO/R rats. Our results demonstrated that ACT attenuates oxidative stress and neuronal apoptosis in MCAO/R rats, suggesting that ACT may serve as a novel therapeutic candidate for the treatment of I/R brain injury.

Multicomponent quantitative analysis combined with antioxidant and alpha-glucosidase inhibitory activities for the quality evaluation of Gastrodia elata from different regions

Gastrodia elata (G. elata), as a natural plant with nourishing and edible value, plays a vital role in food and pharmaceutical production. In the present study, a novel approach for the simultaneous determination of six components based on high-performance liquid chromatography (HPLC) coupled with photodiode array detection (PDA) was developed for the quality evaluation of G. elata from different regions. Meanwhile, antioxidant and α-glucosidase inhibitory activities were estimated and compared. The results indicated that the total contents of the six compounds in G. elata from Guizhou and Zhejiang provinces obtained by boiling were higher than those obtained by steaming in Anhui and Yunnan provinces. In addition, samples from Guizhou, Yunnan and Shanxi provinces contained more p-hydroxybenzyl alcohol, and always possessed higher antioxidant activity, while samples collected from Anhui province showed the highest α-glucosidase inhibitory activity with the highest gastrodin content. The results revealed that the quality of G. elata was affected by different regions and different initial processing technologies, which provided a reference for the selection and application of G. elata.

PKR: A Kinase to Remember

Aging is a major risk factor for many diseases including metabolic syndrome, cancer, inflammation, and neurodegeneration. Identifying mechanistic common denominators underlying the impact of aging is essential for our fundamental understanding of age-related diseases and the possibility to propose new ways to fight them. One can define aging biochemically as prolonged metabolic stress, the innate cellular and molecular programs responding to it, and the new stable or unstable state of equilibrium between the two. A candidate to play a role in the process is protein kinase R (PKR), first identified as a cellular protector against viral infection and today known as a major regulator of central cellular processes including mRNA translation, transcriptional control, regulation of apoptosis, and cell proliferation. Prolonged imbalance in PKR activation is both affected by biochemical and metabolic parameters and affects them in turn to create a feedforward loop. Here, we portray the central role of PKR in transferring metabolic information and regulating cellular function with a focus on cancer, inflammation, and brain function. Later, we integrate information from open data sources and discuss current knowledge and gaps in the literature about the signaling cascades upstream and downstream of PKR in different cell types and function. Finally, we summarize current major points and biological means to manipulate PKR expression and/or activation and propose PKR as a therapeutic target to shift age/metabolic-dependent undesired steady states.

Effect of inorganic salt on partition of high-polarity parishins in two-phase solvent systems and separation by high-speed counter-current chromatography from Gastrodia elata Blume

Parishins are high-polarity and major bioactive constituents in Gastrodia elata Blume. In this study, the effect of several inorganic salts on the partition of parishins in two-phase solvent systems was investigated. Adding ammonium sulfate, which has a higher solubility in water, was found to significantly promote the partition of parishins in the upper organic polar solvents. Based on the results, a two-phase solvent system composed of butyl alcohol/acetonitrile/near-saturated ammonium sulfate solution/water (1.5:0.5:1.2:1, v/v/v/v) was used for the purification of parishins by high-speed counter-current chromatography. Fractions obtained from high-speed counter-current chromatography were subjected to semi-preparative high-performance liquid chromatography to remove salt and impurities. As a result, parishin E (6.0 mg), parishin B (7.8 mg), parishin C (3.2 mg), gastrodin (15.3 mg), and parishin A (7.3 mg) were isolated from water extract of Gastrodia elata Blume (400 mg). These results demonstrated that adding inorganic salt that has high solubility in water to the two-phase solvent system in high-speed counter-current chromatography was a suitable approach for the purification of high-polarity compounds.

Gastrodin Alleviates Cognitive Dysfunction and Depressive-Like Behaviors by Inhibiting ER Stress and NLRP3 Inflammasome Activation in db/db Mice

Patients with diabetes mellitus (DM) suffer more risks from diabetic encephalopathy such as cognitive dysfunction and depressive-like behaviors. Numerous studies show that ER (endoplasmic reticulum) stress and inflammation play important roles in the development of diabetic encephalopathy. Gastrodin (Gas), one major component of Gastrodia elata, is traditionally used in central nervous system disorders and is believed to possess anti-inflammatory, anti-apoptotic, and other neuroprotective effects. This present study aims to explore the protective effects of Gas on diabetic encephalopathy. Gas was administrated daily (70 and 140 mg/Kg) for 12 weeks. Meanwhile, the fasting blood glucose and body weight of db/db mice were measured every two weeks. After Gas treatment, the Morris water maze (MWM) test and novel object recognition (NOR) test were performed to assess the learning and memory functions of db/db mice, and the forced swim test was performed to evaluate depressive-like behaviors of db/db mice. Additionally, the expression of ER stress and Nucleotide binding and oligomerization domain-like (Nod) receptor family pyrin domain-containing 3 (NLRP3) inflammasome related proteins were evaluated by using Western blot. Our study suggested that Gas attenuated blood glucose levels and dyslipidemia of db/db mice. It has been shown that Gas could improve learning and memory function and depressive-like behaviors of db/db mice. Moreover, Gas inhibited ER stress and NLRP3 inflammasome activation in the hippocampus. Taken together, this study demonstrates that Gas attenuates the diabetic encephalopathy by inhibiting ER stress and NLRP3 inflammasome activation.

Gastrodin Ameliorates Cognitive Dysfunction in Diabetes Rat Model via the Suppression of Endoplasmic Reticulum Stress and NLRP3 Inflammasome Activation

Patients with diabetes mellitus (DM) are at high risk for cognitive dysfunction. Endoplasmic reticulum stress (ERS) and inflammation play crucial roles in DM. Gastrodin (Gas), the main component of Gastrodia elata, possesses anti-oxidative stress, anti-inflammatory, and neuroprotective effects. This present study aims to investigate whether Gas could ameliorate cognitive dysfunction in DM and to explore its underlying mechanisms. Rats with streptozotocin-induced type 2 DM were used in this study. After administration of Gas for 5 weeks, the levels of total cholesterol (TC), triglyceride (TG), low density lipoprotein cholesterol (LDL-C) and high density lipoprotein cholesterol (HDL-C) in serum, TNF-α, IL-1β, MDA and SOD in the hippocampus were measured. Morris water maze, hematoxylin and eosin (HE) and Nissl staining were performed to assess the effects of Gas on cognitive function and hippocampal neuronal apoptosis. Protein levels of GLUT3, brain derived neurotrophic factor (BDNF), GRP78, PERK, P-PERK, TXNIP, ASC, NLRP3, CHOP, Bcl-2 and Bax were measured by using Western blot. The results showed that Gas could improve hyperglycemia and dyslipidemia in DM rats, as the levels of TC, TG LDL-C in serum were decreased. TNF-α, IL-1β, MDA contents in the hippocampus were decreased, and SOD contents was increased in the hippocampus of DM rats. Inflammation, oxidative stress, ERS, and apoptosis were observed in the hippocampus of DM rats, accompanied with decreased expression of BDNF and GLUT3. Gas improved the cognitive deficits caused by diabetes and inhibited inflammation, oxidative stress, ERS, and apoptosis in the hippocampus. Furthermore, Gas substantially increased the expression of GLUT3, and inhibited hippocampal ERS and ERS-mediated apoptosis. Additionally, Gas increased the expression of BDNF and decreased the activation of NLRP3 inflammasome. These results suggested that by inhibiting ERS and NLRP3 inflammasome activation and increasing the expression of BDNF and GLUT3, Gas exhibits neuroprotective effects against cognitive dysfunction in DM.

Phytoconstituents and their Possible Mechanistic Profile for Alzheimer's Disease - A Literature Review

Memory is an associated part of life without which livelihood of a human being becomes miserable. As the global aged population is increasing tremendously, time has come to concentrate on tail end life stage diseases. Alzheimer's disease (AD) is one of such diseases whose origin is enigmatic, having an impact on later stage of life drastically due to irreparable damage of cognition, characterised by the presence of neurotoxic amyloid-beta (Aβ) plaques and hyper phosphorylated Tau protein as fibrillary tangles. Existing therapeutic regimen mainly focuses on symptomatic relief by targeting neurotransmitters that are secondary to AD pathology. Plant derived licensed drugs, Galantamine and Huperzine-A were studied extensively due to their AChE inhibitory action for mild to moderate cases of AD. Although many studies have proved the efficacy of AChEIs as a preferable symptom reliever, they cannot offer long term protection. The future generation drugs of AD is expected to alter various factors that underlie the disease course with a symptomatic benefit promise. As AD involves complex pathology, it is essential to consider several molecular divergent factors apart from the events that result in the production of toxic plaques and neurofibrillary tangles. Even though several herbals have shown neuroprotective actions, we have mentioned about the phytoconstituents that have been tested experimentally against different Alzheimer's pathology models. These phytoconstituents need to be considered by the researchers for further drug development process to make them viable clinically, which is currently a lacuna.