Schisandrin B Ameliorates ICV-Infused Amyloid β Induced Oxidative Stress and Neuronal Dysfunction through Inhibiting RAGE/NF-κB/MAPK and Up-Regulating HSP/Beclin Expression

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.

Borneol-Modified Schisandrin B Micelles Cross the Blood-Brain Barrier To Treat Alzheimer's Disease in Aged Mice

Objective: Schisandrin B (Sch B) is a bioactive dibenzocyclooctadiene derizative that is prevalent in the fruit of Schisandra chinensis. Numerous studies have demonstrated that Sch B has a neuroprotective action by reducing oxidative stress and effectively preventing inflammation. It follows that Sch B is a potential treatment for Alzheimer's disease (AD). However, the drug's solubility, bioavailability, and lower permeability of the blood-brain barrier (BBB) can all reduce its efficacy during the therapy process. Therefore, this study constructed borneol-modified schisandrin B micelles (Bor-Sch B-Ms), which increase brain targeting by accurately delivering medications to the brain, effectively improving bioavailability. High therapeutic efficacy has been achieved at the pathological site. Methods: Bor-Sch B-Ms were prepared using the thin film dispersion approach in this article. On the one hand, to observe the targeting effect of borneol, we constructed a blood-brain barrier (BBB) model in vitro and studied the ability of micelles to cross the BBB. On the other hand, the distribution of micelle drugs and their related pharmacological effects on neuroinflammation, oxidative stress, and neuronal damage were studied through in vivo administration in mice. Results: In vitro studies have demonstrated that the drug uptake of bEnd.3 cells was increased by the borneol alteration on the surface of the nano micelles, implying that Bor-Sch B-Ms can promote the therapeutic effect of N2a cells. This could result in more medicines entering the BBB. In addition, in vivo studies revealed that the distribution and circulation time of medications in the brain tissue were significantly higher than those in other groups, making it more suitable for the treatment of central nervous system diseases. Conclusion: As a novel nanodrug delivery system, borneol modified schisandrin B micelles have promising research prospects in the treatment of Alzheimer's disease.

Research Progress on Natural Plant Molecules in Regulating the Blood-Brain Barrier in Alzheimer's Disease

Alzheimer's disease (AD) is a prevalent neurodegenerative disorder. With the aging population and the continuous development of risk factors associated with AD, it will impose a significant burden on individuals, families, and society. Currently, commonly used therapeutic drugs such as Cholinesterase inhibitors, N-methyl-D-aspartate antagonists, and multiple AD pathology removal drugs have been shown to have beneficial effects on certain pathological conditions of AD. However, their clinical efficacy is minimal and they are associated with certain adverse reactions. Furthermore, the underlying pathological mechanism of AD remains unclear, posing a challenge for drug development. In contrast, natural plant molecules, widely available, offer multiple targeting pathways and demonstrate inherent advantages in modifying the typical pathologic features of AD by influencing the blood-brain barrier (BBB). We provide a comprehensive review of recent in vivo and in vitro studies on natural plant molecules that impact the BBB in the treatment of AD. Additionally, we analyze their specific mechanisms to offer novel insights for the development of safe and effective targeted drugs as well as guidance for experimental research and the clinical application of drugs for the prevention and treatment of AD.

Neuroprotective effect of ropinirole against Aβ1-42 -induced neurochemical perturbations and cognitive impairments in a rodent model

The primary objective of this study was to investigate the protective effects of ropinirole (ROP) medication given for an extended period following the induction of cognitive decline, oxidative stress, and deterioration of mitochondria in a Wistar rat model by Aβ1-42 . This study aimed to examine the neuroprotective efficacy of ROP in a stereotaxis model of AD. The Wistar rats were randomly assigned into four groups. Group I was considered as a sham, group II served as Aβ-infusion alone, Group III was Aβ1-42 + ROP (5 mg/kg/i.p.), and Group IV was Aβ1-42 + ROP (10 mg/kg/i.p.). Our research revealed that ROP (10 mg/kg, b.wt.) attenuates the cognitive deficits caused by Aβ1-42 -infused, which also correlates with the barnes maze, where (10 mg/kg, b.w.t.) shows significant improvement in spatial learning and memory. At the same time, ROP was rescued from oxidative damage, decreased lipid peroxidation rates, and inhibited acetylcholinesterase activity caused, demonstrating antioxidant benefits. In addition, a higher dose of ROP restored mitochondrial membrane potential in Aβ1-42 rats. Furthermore, histopathological examination showed that ROP treatment reduced neuronal loss, especially in the hippocampus. We conclude that ROP's protective effects in reducing oxidative stress and modulating mitochondrial function might have a propensity in AD pathogenesis.

The study of therapeutic efficacy and mechanisms of Schisandra chinensis and Evodia rutaecarpa combined treatment in a rat model of Alzheimer's disease

Schisandra chinensis and Evodia rutaecarpa are traditional Chinese herbs used to treat neurodegenerative diseases. This study investigates the combined effects of SC and ER on learning and memory in an Alzheimer's disease rat model and their underlying mechanisms.

Methods

High-performance liquid chromatography was employed to analyze the primary active constituents of Schisandra and Evodia. The effects of the combined treatment of Schisandra and Evodia on learning and memory in an Alzheimer's disease rat model were evaluated through Morris water maze and Hematoxylin-Eosin staining experiments. Immunohistochemical analysis was conducted to investigate the impact of S-E on Aβ1-42 and P-tau proteins. Western blotting and real-time quantitative polymerase chain reaction were utilized to quantify the expression of pivotal proteins and genes within the BDNF/TRKB/CREB and GSK-3β/Tau pathways.

Results

The treatment group exhibited significant neuroprotective effects, ameliorating learning and memory impairments in the Alzheimer's disease rat model. The treatment regimen modulated the activity of the BDNF/TRKB/CREB and GSK-3β/Tau pathways by influencing the expression of relevant genes, thereby reducing the generation of Aβ1-42 and P-Tau proteins and inhibiting the deposition of senile plaques. Furthermore, among the three treatment groups, the combined treatment demonstrated notably superior therapeutic effects on Alzheimer's disease compared to the single-drug treatment groups.

A network pharmacology approach to identify the mechanisms and molecular targets of curcumin against Alzheimer disease

BACKGROUND

Alzheimer disease (AD) is a degenerative brain disease, which may lead to severe memory loss and other cognitive disorders. However, few effective drugs are available in the clinic at present. Curcumin, a major ingredient of traditional Chinese medicine, Curcuma Longa, has various pharmacological activities. Therefore, exploring clinical drugs based on the inhibition of AD pathological features is imperative.

METHODS

First, we utilized the HERB database and Swisstarget Prediction database to get the related targets of curcumin and intersected with the AD targets. The intersection targets were used to construct the protein-protein interaction network and performed gene ontology and kyoto encyclopedia of genes and genomes analyses. Further, we obtained targets of curcumin against AD-related tau and aβ pathology via the AlzData database. These targets were applied to perform GEO and receiver operating characteristic analyses. Finally, the reliability of the core targets was evaluated using molecular docking technology.

RESULTS

We identified 49 targets of curcumin against AD, and kyoto encyclopedia of genes and genomes pathway enrichment analysis demonstrated that the Alzheimer disease pathway (has05010) was significantly enriched. Even more, we obtained 16 targets of curcumin-related Aβ and tau pathology. Among these targets, 8 targets involved the Alzheimer disease pathway and the biological process analyses showed that positive regulation of cytokine production (GO:0001819) was significantly enriched. Bioinformatic analyses indicated that HMOX1, CSF1R, NFKB1, GSK3B, BACE1, AR, or PTGS1 expression was significantly different compared to the control group in the AD patients. Finally, molecular docking studies suggested these genes have a good binding force with curcumin.

CONCLUSIONS

In this study, we identified curcumin exerted the effect of treating AD by regulating multitargets and multichannels through the method of network pharmacology.

Effects of pramipexole on beta-amyloid1-42 memory deficits and evaluation of oxidative stress and mitochondrial function markers in the hippocampus of Wistar rat

Oxidative damage and mitochondrial dysfunction are two prominent pathological features and gradually understood as important pathogenic events for neurodegenerative diseases, including aging and Alzheimer's disease (AD). The present study was aimed to explore the prolonged treatment of pramipexole (PPX) following amyloid beta (Aβ_1-42)-induced cognitive deficits, oxidative stress, and mitochondrial dysfunction in Wistar rat model. We have found that PPX (1.0mg/kg, b.wt.) can rescue cognitive impairments of Aβ_1-42-infused rats in Morris water maze. At the same time, PPX attenuated Aβ_1-42-induced oxidative damage and increased reduced-glutathione content level, decreased lipid peroxidation rate and suppressed the activity of acetylcholinesterase and shows antioxidant effects. Additionally, PPX treatment has shown inhibition of mitochondrial reactive oxygen species production and restored mitochondrial membrane potential, oxidative phosphorylation, and enhanced ATP levels in Aβ_1-42 rats. Furthermore, PPX treatment reduced bioenergetics loss and dynamics alterations by regulating PGC-1α protein level and mitigating translocation of Bax and Drp-1 to mitochondria and cytochrome-c release into the cytoplasm. PPX also increased mitofusin-2 protein expression, a basic element of mitochondrial fusion process. We conclude that remedial role of PPX in mitigating oxidative damage and mitochondrial perturbation that are modulated in Aβ_1-42 rats may have the propensity in AD pathogenesis.

Lignans as Pharmacological Agents in Disorders Related to Oxidative Stress and Inflammation: Chemical Synthesis Approaches and Biological Activities

Plant lignans exhibit a wide range of biological activities, which makes them the research objects of potential use as therapeutic agents. They provide diverse naturally-occurring pharmacophores and are available for production by chemical synthesis. A large amount of accumulated data indicates that lignans of different structural groups are apt to demonstrate both anti-inflammatory and antioxidant effects, in many cases, simultaneously. In this review, we summarize the comprehensive knowledge about lignan use as a bioactive agent in disorders associated with oxidative stress and inflammation, pharmacological effects in vitro and in vivo, molecular mechanisms underlying these effects, and chemical synthesis approaches. This article provides an up-to-date overview of the current data in this area, available in PubMed, Scopus, and Web of Science databases, screened from 2000 to 2022.

Glycogen Synthase Kinase 3β Involvement in Neuroinflammation and Neurodegenerative Diseases

BACKGROUND

GSK-3β activity has been strictly related to neuroinflammation and neurodegeneration. Alzheimer's disease is the most studied neurodegenerative disease, but GSK-3β seems to be involved in almost all neurodegenerative diseases including Parkinson's disease, amyotrophic lateral sclerosis, frontotemporal dementia, Huntington's disease and the autoimmune disease multiple sclerosis.

OBJECTIVE

The aim of this review is to help researchers both working on this research topic or not to have a comprehensive overview on GSK-3β in the context of neuroinflammation and neurodegeneration.

METHOD

Literature has been searched using PubMed and SciFinder databases by inserting specific keywords. A total of more than 500 articles have been discussed.

RESULTS

First of all, the structure and regulation of the kinase were briefly discussed and then, specific GSK-3β implications in neuroinflammation and neurodegenerative diseases were illustrated also with the help of figures, to conclude with a comprehensive overview on the most important GSK-3β and multitarget inhibitors. For all discussed compounds, the structure and IC50 values at the target kinase have been reported.

CONCLUSION

GSK-3β is involved in several signaling pathways both in neurons as well as in glial cells and immune cells. The fine regulation and interconnection of all these pathways are at the base of the rationale use of GSK-3β inhibitors in neuroinflammation and neurodegeneration. In fact, some compounds are now under clinical trials. Despite this, pharmacodynamic and ADME/Tox profiles of the compounds were often not fully characterized and this is deleterious in such a complex system.

Idebenone Decreases Aβ Pathology by Modulating RAGE/Caspase-3 Signaling and the Aβ Degradation Enzyme NEP in a Mouse Model of AD

Simple Summary

The present study reveals that the FDA-approved drug idebenone has therapeutic effects on the pathology of Alzheimer’s disease (AD) in a mouse model. In particular, idebenone regulates pathological progression associated with Aβ by downregulating the non-amyloidogenic pathway, inhibiting RAGE/caspase-3 signaling, and enhancing Aβ catabolism. In addition, idebenone modulates tauopathy by reducing levels of the tau kinase p-GSK3β, thereby suppressing tau hyperphosphorylation at Thr231. These data suggest that idebenone modulates Aβ and tau pathology in a mouse model of AD.

Abstract

The coenzyme Q10 analogue idebenone is an FDA-approved antioxidant that can cross the blood–brain barrier (BBB). The effects of idebenone on the pathology of Alzheimer’s disease (AD) and the underlying molecular mechanisms have not been comprehensively investigated. Here, we examined the impact of idebenone treatment on AD pathology in 5xFAD mice, a model of AD. Idebenone significantly downregulated Aβ plaque number via multi-directional pathways in this model. Specifically, idebenone reduced the RAGE/caspase-3 signaling pathway and increased levels of the Aβ degradation enzyme NEP and α-secretase ADAM17 in 5xFAD mice. Importantly, idebenone significantly suppressed tau kinase p-GSK3β^Y216 levels, thereby inhibiting tau hyperphosphorylation at Thr231 and total tau levels in 5xFAD mice. Taken together, the present study indicates that idebenone modulates amyloidopathy and tauopathy in 5xFAD mice, suggesting therapeutic potential for AD.

The neuroprotective effects of polyphenols, their role in innate immunity and the interplay with the microbiota

Neurodegenerative disorders, particularly in the elderly population, represent one of the most pressing social and health-care problems in the world. Besides the well-established role of both oxidative stress and inflammation, alterations of the immune response have been found to be closely linked to the development of neurodegenerative diseases. Interestingly, various scientific evidence reported that an altered gut microbiota composition may contribute to the development of neuroinflammatory disorders. This leads to the proposal of the concept of the gut-brain-immune axis. In this scenario, polyphenols play a pivotal role due to their ability to exert neuroprotective, immunomodulatory and microbiota-remodeling activities. In the present review, we summarized the available literature to provide a scientific evidence regarding this neuroprotective and immunomodulatory effects and the interaction with gut microbiota of polyphenols and, the main signaling pathways involved that can explain their potential therapeutic application in neurodegenerative diseases.

Ameliorative effects of Schisandrin B on Schistosoma mansoni-induced hepatic fibrosis in vivo

Schistosomiasis is second only to malaria as the most devastating parasitic disease in the world. It is caused by the helminths Schistosoma mansoni (S. mansoni), S. haematobium, or S. japonicum. Typically, patients with schistosomiasis suffer from symptoms of liver fibrosis and hepatosplenomegaly. Currently, patients were treated with praziquantel. Although praziquantel effectively kills the worm, it cannot prevent re-infection or resolve liver fibrosis. Also, current treatment options are not ample to completely cure liver fibrosis and splenic damages. Moreover, resistance of praziquantel has been reported in vivo and in vitro studies. Therefore, finding new effective treatment agents is urgently needed. Schisandrin B (Sch B) of Schisandra chinensis has been shown to protect against different liver injuries including fatty liver disease, hepatotoxicity, fibrosis, and hepatoma. We herein investigate the potential of using Sch B to treat S. mansoni-induced liver fibrosis. Results from the present study demonstrate that Sch B is beneficial in treating S. mansoni-induced liver fibrosis and splenic damages, through inhibition of inflammasome activation and apoptosis; and aside from that regulates host immune responses. Besides, Sch B treatment damages male adult worm in the mice, consequently helps to reduce egg production and lessen the parasite burden.

Natural products as geroprotectors: An autophagy perspective

Over the past decade, significant attention has been given to repurposing Food and Drug Administration approved drugs to treat age-related diseases. In contrast, less consideration has been given to natural bioactive compounds. Consequently, there have been limited attempts to translate these compounds. Autophagy is a fundamental biological pathway linked to aging, and numerous strategies to enhance autophagy have been shown to extend lifespan. Interestingly, there are a number of natural products that are reported to modulate autophagy, and here we describe a number of them that activate autophagy through diverse molecular and cellular mechanisms. Among these, Urolithin A, Spermidine, Resveratrol, Fatty Acids and Phospholipids, Trehalose and Lithium are featured in detail. Finally, we outline possible strategies to optimise and increase the translatability of natural products, with the overall aim of delaying the ageing process and improving human healthspan.

Natural products as pharmacological modulators of mitochondrial dysfunctions for the treatments of Alzheimer's disease: A comprehensive review

Alzheimer's disease (AD) is the most common progressive neurodegenerative disorder characterized by neuronal loss and cognitive impairment that harshly affect the elderly individuals. Currently, the available anti-AD pharmacological approaches are purely symptomatic to alleviate AD symptoms, and the curative effects of novel anti-AD drugs focused on Aβ target are disappointing. Hence, there is a tremendous need to adjust AD therapeutic targets and discover novel anti-AD agents. In AD, mitochondrial dysfunction gradually triggers neuronal death from different aspects and worsens the occurrence and progress of AD. Consequently, it has been proposed that the intervention of impaired mitochondria represents an attractive breakthrough point for AD treatments. Due to chemical diversity, poly-pharmacological activities, few adverse effects and multiple targeting, natural products (NPs) have been identified as a valuable treasure for drug discovery and development. Multiple lines of studies have scientifically proven that NPs display ameliorative benefits in AD treatment in relation to mitochondrial dysfunction. This review surveys the complicated implications for mitochondrial dysregulation and AD, and then summarizes the potentials of NPs and their underlying molecular mechanisms against AD via reducing or improving mitochondrial dysfunction. It is expected that this work may open the window to speed up the development of innovative anti-AD drugs originated from NPs and improve upcoming AD therapeutics.

Protective effects of intracerebroventricular adiponectin against olfactory impairments in an amyloid β1-42 rat model

BACKGROUND

Alzheimer's disease (AD) is characterized by cognitive impairment that eventually develops into dementia. Amyloid-beta (Aβ) accumulation is a widely described hallmark in AD, and has been reported to cause olfactory dysfunction, a condition considered an early marker of the disease associated with injuries in the olfactory bulb (OB), the hippocampus (HIPP) and other odor-related cortexes. Adiponectin (APN) is an adipokine with neuroprotective effects. Studies have demonstrated that APN administration decreases Aβ neurotoxicity and Tau hyperphosphorylation in the HIPP, reducing cognitive impairment. However, there are no studies regarding the neuroprotective effects of APN in the olfactory dysfunction observed in the Aβ rat model. The aim of the present study is to determine whether the intracerebroventricular (i.c.v) administration of APN prevents the early olfactory dysfunction in an i.c.v Amyloid-beta1-42 (Aβ1-42) rat model. Hence, we evaluated olfactory function by using a battery of olfactory tests aimed to assess olfactory memory, discrimination and detection in the Aβ rat model treated with APN. In addition, we determined the number of cells expressing the neuronal nuclei (NeuN), as well as the number of microglial cells by using the ionized calcium-binding adapter molecule 1 (Iba-1) marker in the OB and, CA1, CA3, hilus and dentate gyrus (DG) in the HIPP. Finally, we determined Arginase-1 expression in both nuclei through Western blot.

RESULTS

We observed that the i.c.v injection of Aβ decreased olfactory function, which was prevented by the i.c.v administration of APN. In accordance with the olfactory impairment observed in i.c.v Aβ-treated rats, we observed a decrease in NeuN expressing cells in the glomerular layer of the OB, which was also prevented with the i.c.v APN. Furthermore, we observed an increase of Iba-1 cells in CA1, and DG in the HIPP of the Aβ rats, which was prevented by the APN treatment.

CONCLUSION

The present study describes the olfactory impairment of Aβ treated rats and evidences the protective role that APN plays in the brain, by preventing the olfactory impairment induced by Aβ1-42. These results may lead to APN-based pharmacological therapies aimed to ameliorate AD neurotoxic effects.

Pharmacodynamic effects and molecular mechanisms of lignans from Schisandra chinensis Turcz. (Baill.), a current review

Fruit of Schisandra chinensis Turcz. (Baill.) (S. chinensis) is a traditional herbal medicine widely used in China, Korea, and many other east Asian countries. At present, S. chinensis commonly forms Chinese medicinal formulae with other herbal medicines to treat liver disease and neurological disease in clinical. Modern researches indicated that lignans were the main active ingredients of S. chinensis with high content and novel dibenzocyclooctadiene skeletal structure, exhibited considerable antioxidant, anti-inflammatory, and neuroprotective properties. Additionally, some of these lignans also showed certain potentials in anti-cancer, anti-fibrosis, and other effects. In the current review, we summarize literature reported lignans from S. chinensis in the past five years, and highlight the molecular mechanisms of lignans in exerting their biological functions. Also, we point out some deficiencies of existing researches and discuss the future direction of lignans study.

Rapid action of mechanism investigation of Yixin Ningshen tablet in treating depression by combinatorial use of systems biology and bioinformatics tools

ETHNOPHARMACOLOGICAL RELEVANCE

Yixin Ningshen tablet is a CFDA-approved TCM formula for treating depression clinically. However, little is known about its active compounds and related potential target proteins, so far, no researches have been performed to investigate its mechanism of action for the treatment of depression.

AIM OF THE STUDY

Here we develop an original bioinformatics pipeline composed of text mining tools, database querying and systems biology combinatorial analysis, which is applied to rapidly explore the mechanism of action of Yixin Ningshen tablet in treating depression.

MATERIALS AND METHODS

Text mining and database query were applied to identify active compounds in Yixin Ningshen tablet for the treatment of depression. Then SwissTargetPrediction was used to predict their potential target proteins. PubMed was retrieved to summarize known depression related systems biology results. Ingenuity Pathway Analysis (IPA) tools and STRING were applied to construct a compound-target protein-gene protein-differential protein-differential metabolite network with the integration of compound-target interaction and systems biology results, as well as enrich the target proteins related pathways. ChEMBL and CDOCKER were used to validate the compound-target interactions.

RESULTS

62 active compounds and their 286 potential target proteins were identified in Yixin Ningshen tablet for the treatment of depression. The construction of compound-target protein-gene protein-differential protein-differential metabolite network shrinked the number of potential target proteins from 286 to 133. Pathway enrichment analysis of target proteins indicated that Neuroactive ligand-receptor interaction, Calcium signaling pathway, Serotonergic synapse, cAMP signaling pathway and Gap junction were the common primary pathways regulated by both Yixin Ningshen Tablet and anti-depressant drugs, and MAPK, Relaxin, AGE-RAGE, Estrogen, HIF-1, Jak-STAT signaling pathway, Endocrine resistance, Arachidonic acid metabolism and Regulation of actin cytoskeleton were the specifically main pathways regulated by Yixin Ningshen tablet for the treatment of depression. Further validations based on references and molecular docking results demonstrated that Yixin Ningshen tablet could primarily target MAPT, CHRM1 and DRD1, thus regulating serotonergic neurons, cholinergic transmission, norepinephrine and dopamine reuptake for the treatment of depression.

CONCLUSIONS

This study displays the power of extensive mining of public data and bioinformatical repositories to provide answers for a specific pharmacological question. It furthermore demonstrates how the usage of such a combinatorial approach is advantageous for the biologist in terms of experimentation time and costs.

Targeting apoptosis and autophagy following spinal cord injury: Therapeutic approaches to polyphenols and candidate phytochemicals

Spinal cord injury (SCI) is a neurological disorder associated with the loss of sensory and motor function. Understanding the precise dysregulated signaling pathways, especially apoptosis and autophagy following SCI, is of vital importance in developing innovative therapeutic targets and treatments. The present study lies in the fact that it reveals the precise dysregulated signaling mediators of apoptotic and autophagic pathways following SCI and also examines the effects of polyphenols and other candidate phytochemicals. It provides new insights to develop new treatments for post-SCI complications. Accordingly, a comprehensive review was conducted using electronic databases including, Scopus, Web of Science, PubMed, and Medline, along with the authors' expertise in apoptosis and autophagy as well as their knowledge about the effects of polyphenols and other phytochemicals on SCI pathogenesis. The primary mechanical injury to spinal cord is followed by a secondary cascade of apoptosis and autophagy that play critical roles during SCI. In terms of pharmacological mechanisms, caspases, Bax/Bcl-2, TNF-α, and JAK/STAT in apoptosis along with LC3 and Beclin-1 in autophagy have shown a close interconnection with the inflammatory pathways mainly glutamatergic, PI3K/Akt/mTOR, ERK/MAPK, and other cross-linked mediators. Besides, apoptotic pathways have been shown to regulate autophagy mediators and vice versa. Prevailing evidence has highlighted the importance of modulating these signaling mediators/pathways by polyphenols and other candidate phytochemicals post-SCI. The present review provides dysregulated signaling mediators and therapeutic targets of apoptotic and autophagic pathways following SCI, focusing on the modulatory effects of polyphenols and other potential phytochemical candidates.

Albendazole-Schisandrin B Co-Therapy on Angiostrongylus cantonensis-Induced Meningoencephalitis in Mice

Currently, Angiostrongylus cantonensis infections are predominantly treated with albendazole. However, the use of albendazole can provoke certain neurological symptoms as a result of the immune response triggered by the dead worms. Therefore, treatment usually involves co-administration of corticosteroids to limit the inflammatory reaction. Corticosteroids play a useful role in suppressing inflammation in the brain; however, long-term usage or high dosage may make it problematic.Schisandrin B, an active ingredient from Schisandra chinensis, has been shown to have anti-inflammatory effects on the brain. This study aimed to investigate the effects and potential of schisandrin B in combination with albendazole to treat Angiostrongylus-induced meningoencephalitis. Here, we show that albendazole-schisandrin B co-treatment suppressed neuroinflammation in Angiostrongylus-infected mice and increased the survival of the mice. Accordingly, albendazole-schisandrin B co-treatment significantly inhibited inflammasome activation, pyroptosis, and apoptosis. The sensorimotor functions of the mice were also repaired after albendazole-schisandrin B treatment. Immune response was shown to shift from Th2 to Th1, which reduces inflammation and enhances immunity against A. cantonensis. Collectively, our study showed that albendazole-schisandrin B co-therapy may be used as an encouraging treatment for Angiostrongylus-induced meningoencephalitis.

Promiscuous Roles of Autophagy and Proteasome in Neurodegenerative Proteinopathies

Alterations in autophagy and the ubiquitin proteasome system (UPS) are commonly implicated in protein aggregation and toxicity which manifest in a number of neurological disorders. In fact, both UPS and autophagy alterations are bound to the aggregation, spreading and toxicity of the so-called prionoid proteins, including alpha synuclein (α-syn), amyloid-beta (Aβ), tau, huntingtin, superoxide dismutase-1 (SOD-1), TAR-DNA-binding protein of 43 kDa (TDP-43) and fused in sarcoma (FUS). Recent biochemical and morphological studies add to this scenario, focusing on the coordinated, either synergistic or compensatory, interplay that occurs between autophagy and the UPS. In fact, a number of biochemical pathways such as mammalian target of rapamycin (mTOR), transcription factor EB (TFEB), Bcl2-associated athanogene 1/3 (BAG3/1) and glycogen synthase kinase beta (GSk3β), which are widely explored as potential targets in neurodegenerative proteinopathies, operate at the crossroad between autophagy and UPS. These biochemical steps are key in orchestrating the specificity and magnitude of the two degradation systems for effective protein homeostasis, while intermingling with intracellular secretory/trafficking and inflammatory pathways. The findings discussed in the present manuscript are supposed to add novel viewpoints which may further enrich our insight on the complex interactions occurring between cell-clearing systems, protein misfolding and propagation. Discovering novel mechanisms enabling a cross-talk between the UPS and autophagy is expected to provide novel potential molecular targets in proteinopathies.

Neuroprotection of Tropical Fruit Juice Mixture via the Reduction of iNOS Expression and CRH Level in β-Amyloid-Induced Rats Model of Alzheimer's Disease

This study aimed to determine the effects of tropical fruit juice mixture (pomegranate, white guava, and Roselle) on biochemical, behavioral, and histopathological changes of β-amyloid- (Aβ-) induced rats. Formulation 8 (F8) of tropical fruit juice mixture was chosen for this present study due to its high phenolic content and antioxidant capacity. Forty Wistar male rats were divided into five groups: dPBS (sham-operated control), dAβ (Aβ control), JPBS (F8 and PBS), JAβ (F8 and Aβ), and IBFAβ (ibuprofen and Aβ). F8 (5 ml/kg BW), and ibuprofen (10 ml/kg BW) was given orally daily for four weeks before the intracerebroventricular infusion of Aβ for two weeks. Histological analysis and neuronal count of hippocampus tissue in the Cornu Ammonis (CA1) region showed that supplementation with F8 was able to prevent Aβ-induced tissue damage and neuronal shrinkage. However, no significant difference in locomotor activity and novel object recognition (NOR) percentage was detected among different groups at day 7 and day 14 following Aβ infusion. Only effect of time differences (main effect of day) was observed at day 7 as compared to day 14, where reduction in locomotor activity and NOR percentage was observed in all groups, with F (1, 7) = 6.940, p < 0.05 and F (1, 7) = 7.152, p < 0.05, respectively. Besides, the MDA level of the JAβ group was significantly lower (p < 0.01) than that of the dPBS group. However, no significant changes in SOD activity were detected among different groups. Significant reduction in plasma CRH level (p < 0.05) and iNOS expression (p < 0.01) in the brain was detected in the JAβ group as compared to the dAβ group. Hence, our current findings suggest that the tropical fruit juice mixture (F8) has the potential to protect the rats from Aβ-induced neurotoxicity in brain hippocampus tissue possibly via its antioxidant properties and the suppression of iNOS expression and CRH production.

A Comprehensive Review on Schisandrin B and Its Biological Properties

Nature is a vast source of bioactive molecules and has provided an active and efficient reservoir for drug discovery. Among natural compounds, one of the most promising is Schisandrin B (Sch B), isolated from Schisandra chinensis, which was documented to possess diversified pharmacokinetic propriety, among them antioxidant, anti-inflammation, cardioprotection, and neuroprotection. Due to its large biological properties, Sch B was recorded to be a potent cure for several diseases by targeting several signaling pathways. This review is aimed at emphasizing the recent data on the biological properties of Sch B among the molecular mechanism of this drug on tumoral, cardiac, and neural diseases. The data suggest that the antitumor activities of Sch B were mainly through apoptosis and cell cycle arrest at the diver's stage. It is reported that Sch B could be used as effective chemotherapy, neuroprotection, and cardioprotection since it possesses a spectrum of biological activities; however, further investigations on the mechanism of its action and preclinical trials are still mandatory to further validate the potential of this natural drug candidate.

3,4-Dihydroxybenzalacetone (DBL) Prevents Aging-Induced Myocardial Changes in Senescence-Accelerated Mouse-Prone 8 (SAMP8) Mice

Aging is a predominant risk factor for the development and progression of cardiovascular complications. Physiologically and anatomically, the heart undergoes numerous changes that result in poor cardiac function in the elderly population. Recently, several studies have provided promising results, confirming the ability of the senescence-accelerated mouse-prone 8 (SAMP8) model to accurately model age-related cardiovascular alterations. In this study, using a murine model of senescence, SAMP8, we aimed to investigate the effect of 3,4-dihydroxybenzalacetone (DBL), a catechol-containing phenylpropanoid derivative isolated from Inonotus obliquus (Chaga), on cardiac aging. DBL was administered at the doses of 10 mg/kg and 20 mg/kg by oral gavage to SAMP8 mice to examine aging-mediated cardiac changes, such as oxidative DNA damage, oxygen radical antioxidant capacity (ORAC) value, fibrosis, inflammation, and apoptosis. The treatment with DBL at both doses significantly reduced aging-mediated oxidative DNA damage, and simultaneously increased the ORAC value in the SAMP8 assay. Cardiac fibrosis was assessed with Azan-Mallory staining, and the number of cardiac remodeling markers was found to be significantly reduced after the treatment with DBL. We also observed a decrease in cardiomyocyte apoptosis as measured by the terminal transferase-mediated dUTP nick end labeling (TUNEL) staining method and the caspase-3 levels in SAMP8 mice compared with senescence-resistant control (SAMR1) mice. The findings from this study suggest that DBL has a potentially beneficial effect on aging-mediated myocardial alterations. Further studies are warranted to confirm the promising potential of this catechol compound against aging-associated myocardial dysfunction.

A systematic strategy for screening therapeutic constituents of Schisandra chinensis (Turcz.) Baill infiltrated blood-brain barrier oriented in lesions using ethanol and water extracts: a novel perspective for exploring chemical material basis of herb medicines

Schisandra chinensis, a widely used Chinese herbal medicine, was considered as central nervous system (CNS) drug for years. Both ethanol extracts (EES) and water extracts (WES) of it were applied clinically. Unfortunately, the difference of their efficacy and even effective material foundation of S. chinensis remains obscure. In this study, to explore the active constituents of S. chinensis, we compared pharmacodynamics and chemical profiles in vitro/in vivo of EES/WES for the first time using multiple chemical analysis, pharmacological and data processing approaches. It was proved that there was no significant difference in the anti-depressive effects between WES and EES. However, the contents of most components in vitro and in plasma were higher in EES than those in WES, which was unconvincing for their similar efficacy. Therefore, we further explored components of S. chinensis targeted onto brain and the results showed that 5 lignans were identified with definite absorptivity respectively both in EES and WES caused by the limitation of blood−brain barrier. Moreover, bioinformatic analysis predicted their anti-depressive action. Above all, the systematic strategy screened 5 brain-targeted effective substances of S. chinensis and it was suggested that exploring the components into nidi would promote the studies on herbs effective material basis.

Schisandrin A and B enhance the dentate gyrus neurogenesis in mouse hippocampus

Schisandrin A and B (Sch A and B) are the main effective components of Schisandra chinensis (S. chinensis), which is traditionally used to enhance mental and intellectual functions in eastern Asia. Previously, we reported Sch A and B remarkably affect adult neurogenesis in the subventricular zone of mouse lateral ventricle. Since the neurogenesis in the hippocampal dentate gyrus (DG) is more important to learning, memory and cognition, here we further examined their effects on the adult DG neurogenesis. Phosphohistone H3 (PHH3) immunostaining showed that Sch B significantly enhanced the cell proliferation in the DG. Glial fibrillary acidic protein (GFAP, mostly labels astrocytes and some stem cells) staining was used to further identify the proliferating cell type. Dramatically, increases of GFAP⁺ cells in both Sch A and B treated groups were observed. What's more, the total numbers of the mature neurons labeled by neuron-specific nuclear protein (NeuN) were also increased in both Sch A and B treated groups compared with the controls. Together, Sch A and B enhance the adult DG neurogenesis by increasing astrocytes/stem cells and improving the survival and maturation of DG neurons. Our study shed a new light on the neuropharmacological functions of the herbal medicine S. chinensis.

Schizandrol A protects against Aβ1-42-induced autophagy via activation of PI3K/AKT/mTOR pathway in SH-SY5Y cells and primary hippocampal neurons

Autophagy, a lysosomal degradative pathway, is crucial for the pathogenesis of Alzheimer's disease (AD). Schizandrol A (SchA) shows multiple pharmacological effects. However, the potential effects and mechanisms of SchA on amyloid-β (Aβ)-induced autophagy remain unclear. In this study, differentiated SH-SY5Y cells or primary hippocampal neurons were pretreated with SchA (2 μg/ml) for 1 h before subjected to Aβ_1-42 (10 μM) for 24 h to test its effects on cell viability, apoptosis, oxidative stress, and autophagy. Then an mTOR inhibitor (rapamycin) and a PI3K inhibitor (LY294002) were employed to explore the role of PI3K/AKT/mTOR pathway. The results showed that SchA significantly inhibited Aβ_1-42-triggered reduction of viable cells, increases of apoptotic cell number and pro-apoptotic protein expressions, as well as alterations of oxidative stress markers. In addition, the increases of LC3-II/LC3-I and Beclin-1 and decrease of p62 were suppressed by SchA. At the molecular level, we found that the inactivation of PI3K/AKT/mTOR pathway was ameliorated by SchA. Inhibition of PI3K/AKT/mTOR pathway deteriorated the protective effects of SchA against Aβ_1-42-induced autophagy activation, cell death, and apoptosis. In conclusion, we demonstrate that SchA attenuates Aβ_1-42-induced autophagy through activating PI3K/AKT/mTOR signaling pathway. SchA may be a novel drug for the prevention and treatment of AD.

Schizandrin Protects against OGD/R-Induced Neuronal Injury by Suppressing Autophagy: Involvement of the AMPK/mTOR Pathway

The neuroprotective role of schizandrin (SA) in cerebral ischemia-reperfusion (I/R) was recently highlighted. However, whether SA plays a regulatory role on autophagy in cerebral I/R injury is still unclear. This study aimed to explore whether the neuroprotective mechanisms of SA were linked to its regulation of AMP-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR)/autophagy pathway in vivo and in vitro. The present study confirmed that SA significantly improved oxygen-glucose deprivation/re-oxygenation (OGD/R)-induced PC12 cells injury. The results of immunoblotting and confocal microscope showed that SA decreased autophagy in OGD/R-injured PC12 cells, which was reflected by the decreased Beclin-1 and LC3-II expression, autophagy flux level, and LC3 puncta formation. In addition, the autophagy inducer rapamycin partially prevented the effects of SA on cell viability and autophagy after OGD/R, whereas the autophagy inhibitor 3-methyladenine (3-MA) exerted the opposite effect. The results of Western blotting showed that SA markedly decreased the phosphorylation of AMPK (p-AMPK), whereas the phosphor-mTOR (p-mTOR) levels increased in the presence of OGD/R insult. Furthermore, pretreatment with the AMPK inducer AICAR partially reversed the protective effects and autophagy inhibition of SA. However, AMPK inhibitor Compound C pretreatment further promoted the inhibition of SA on autophagy induction and cell damage induced by OGD/R. Taken together, these findings demonstrate that SA protects against OGD/R insult by inhibiting autophagy through the regulation of the AMPK-mTOR pathway and that SA may have therapeutic value for protecting neurons from cerebral ischemia.

Essential oil of Schisandra chinensis ameliorates cognitive decline in mice by alleviating inflammation

In this study, we aim to assess possible impacts of essential oil (SEO) from Schisandra chinensis (Turcz.) Baill. (S. chinensis) on mice with cognition impairment. Our data showed that SEO improved the cognitive ability of mice with Aβ_1-42 or lipopolysaccharides (LPS)-induced Alzheimer's disease (AD) and suppressed the production of tumor necrosis factor-a (TNF-a), interleukin-6 (IL-6), and interleukin-1β (IL-1β) in the hippocampus. Furthermore, SEO inhibited p38 activation, but had little effect on other signaling proteins in the MAPK family, such as extracellular signal-regulated kinase 1/2 (ERK1/2) and c-Jun N-terminal kinase 1/2 (JNK). The SEO and BV-2 microglia co-culture was performed to further confirm the anti-inflammatory activity of SEO. The data showed that SEO decreased nitric oxide (NO) levels in LPS-stimulated BV-2 microglia and significantly blocked LPS-induced MAPKs activation. Taken together, these findings suggested that SEO produces anti-AD effects on AD mice partly by modulating neuroinflammation through the NF-κB/MAPK signaling pathway.

Polysaccharide of Schisandra Chinensis Fructus ameliorates cognitive decline in a mouse model of Alzheimer's disease

ETHNOPHARMACOLOGICAL RELEVANCE

Polysaccharides is an important ingredient of Schisandra Chinensis Fructus which often appears in ancient prescriptions for forgetfulness or dementia.

AIM OF THE STUDY

The purpose of our study is to investigate the effects of polysaccharides of Schisandra Chinensis Fructus (SCP) on animal model of Alzheimer's disease (AD), which is a common disease of dementia, to elucidate the traditional medical theories with modern pharmacological methods and provide a reference for further clarifying its active mechanisms.

MATERIALS AND METHODS

Hydrolysates of SCP were analyzed by HPLC. Y-maze, Morris water maze (MWM) were used for evaluating cognition processes of mice. Immunohistochemistry (IHC) was used to detect the deposition of Aβ. The levels of cytokine expression including Tumor Necrosis Factor α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6) in the hippocampus were detected by ELISA kits. Activation of astrocytes and microglia was assessed by immunofluorescence labeling GFAP and Iba-1. The phosphorylated state of various mitogen-activated protein kinase (MAPKs) signaling molecules (p38 MAPK, ERK 1/2, and JNK) and activation of nuclear factor κB (NF-κB) was studied by western blot. Histopathological changes were observed by H.E. straining.

RESULTS

SCP could significantly improve the cognition and histopathological changes of AD mice, reduce the deposition of Aβ, downregulate the expression of pro-inflammatory cytokines and the activation of glial cells in the hippocampus. Further, SCP decreased nuclear displacement of NF-κB and MAPKs phosphorylation.

CONCLUSIONS

SCP could improve the cognition of mice, and it may play an anti-AD role by activating the NF-κB/MAPK pathway to alleviate neuroinflammation.

Stereoisomers of Schisandrin B Are Potent ATP Competitive GSK-3β Inhibitors with Neuroprotective Effects against Alzheimer's Disease: Stereochemistry and Biological Activity

Glycogen synthase kinase-3β (GSK-3β) is a key enzyme in hyperphosphorylation of tau proteins and is a promising therapeutic target in Alzheimer's disease (AD). Here, we reported, for the first time, that the stereoisomers of Schisandrin B (Sch B), (+)-1, (-)-1, (+)-2, and (-)-2, were potent GSK-3β inhibitors. They were demonstrated to selectively target GSK-3β in an orthosteric binding mode, with IC₅₀ values of 340, 290, 80, and 70 nM, respectively. Further study showed that these stereoisomers can significantly increase the expression of p-GSK-3β (Ser9) and decrease the expressions of p-GSK-3β (Tyr216) and p-GSK-3β (Tyr279). Finally, these compounds can alleviate the cell injury induced by Aβ, and the cognitive disorders in AD mice, especially (+)-2 and (-)-2. Collectively, the stereoisomers of Sch B, especially (+)-2 and (-)-2, were found to be potential selective ATP-competitive GSK-3β inhibitors, which further affected their anti-AD effects. These promising findings explained the biological target of Sch B in AD, and bring a new understanding in the stereochemistry and bioactivities of Sch B.

Autophagy in Human Health and Disease: Novel Therapeutic Opportunities

SIGNIFICANCE

In eukaryotes, autophagy represents a highly evolutionary conserved process, through which macromolecules and cytoplasmic material are degraded into lysosomes and recycled for biosynthetic or energetic purposes. Dysfunction of the autophagic process has been associated with the onset and development of many human chronic pathologies, such as cardiovascular, metabolic, and neurodegenerative diseases as well as cancer. Recent Advances: Currently, comprehensive research is being carried out to discover new therapeutic agents that are able to modulate the autophagic process in vivo. Recent evidence has shown that a large number of natural bioactive compounds are involved in the regulation of autophagy by modulating several transcriptional factors and signaling pathways.

CRITICAL ISSUES

Critical issues that deserve particular attention are the inadequate understanding of the complex role of autophagy in disease pathogenesis, the limited availability of therapeutic drugs, and the lack of clinical trials. In this context, the effects that natural bioactive compounds exert on autophagic modulation should be clearly highlighted, since they depend on the type and stage of the pathological conditions of diseases.

FUTURE DIRECTIONS

Research efforts should now focus on understanding the survival-supporting and death-promoting roles of autophagy, how natural compounds interact exactly with the autophagic targets so as to induce or inhibit autophagy and on the evaluation of their pharmacological effects in a more in-depth and mechanistic way. In addition, clinical studies on autophagy-inducing natural products are strongly encouraged, also to highlight some fundamental aspects, such as the dose, the duration, and the possible synergistic action of these compounds with conventional therapy.

Schisandrin C enhances odontoblastic differentiation through autophagy and mitochondrial biogenesis in human dental pulp cells

OBJECTIVE

To investigate the role of Schisandrin C in odontoblastic differentiation, and its relations between autophagy and mitochondrial biogenesis in human dental pulp cells (HPDCs).

DESIGN

Fresh third molars were used, and cultured for HDPCs. Western blotting technique, Alizarin red S staining, alkaline phosphatase (ALP) activity, and confocal microscopy were used to detect autophagy, mitochondrial biogenesis, and odontoblastic differentiation. To understand the mechanism of Schisandrin C, the HDPCs were treated with lipopolysaccharide (LPS), autophagy and heme oxygenase-1 (HO-1) inhibitors: 3-Methyladenine (3-MA) and Zinc protoporphyrin IX (ZnPP), respectively.

RESULTS

LPS decreased the expression of autophagy molecules [autophagy protein 5 (ATG-5), beclin-1, and microtubule-associated protein 1A/1B light chain 3 (LC3-I/II)] and mitochondrial biogenesis molecules [heme oxygenase-1 (HO-1) and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α)], and disrupted odontoblastic differentiation. The down-regulation of autophagy and mitochondrial biogenesis with 3-MA and ZnPP inhibited odontoblastic differentiation. However, Schisandrin C restored the expression of all the above molecules, even with LPS and inhibitor treatment. This result demonstrates that autophagy and mitochondrial biogenesis plays an essential role in odontoblastic differentiation, and Schisandrin C activates these systems to promote odontoblastic differentiation of HDPCs.

CONCLUSION

Schisandrin C has potential characters to regulate odontoblastic differentiation, and may be recommended for use as a compound for pulp homeostasis.

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.

Schisandra chinensis Fructus and Its Active Ingredients as Promising Resources for the Treatment of Neurological Diseases

Neurological diseases (NDs) are a leading cause of death worldwide and tend to mainly affect people under the age of 50. High rates of premature death and disability caused by NDs undoubtedly constrain societal development. However, effective therapeutic drugs and methods are very limited. Schisandra chinensis Fructus (SCF) is the dry ripe fruit of Schisandra chinensis (Turcz.) Baill, which has been used in traditional Chinese medicine for thousands of years. Recent research has indicated that SCF and its active ingredients show a protective role in NDs, including cerebrovascular diseases, neurodegenerative diseases, or depression. The key neuroprotective mechanisms of SCF and its active ingredients have been demonstrated to include antioxidation, suppression of apoptosis, anti-inflammation, regulation of neurotransmitters, and modulation of brain-derived neurotrophic factor (BDNF) related pathways. This paper summarizes studies of the role of SCF and its active ingredients in protecting against NDs, and highlights them as promising resources for future treatment. Furthermore, novel insights on the future challenges of SCF and its active ingredients are offered.

Cognitive enhancement of volatile oil from the stems of Schisandra chinensis Baill. in Alzheimer’s disease rats

The volatile oil (VO), extracted from the stems of Schisandra chinensis Baill. (SCS), was separated and identified by gas chromatography – mass spectrometry. The study was devised to investigate the effects of VO on oxidative stress and cognitive deficits induced by amyloid-β (Aβ(1-42)). Alzheimer’s disease (AD) models were established by injecting Aβ(1-42) into the rat hippocampus and the effects of learning and memory were observed by a Morris water maze test, immunohistological alterations, and correlative indicators covering nerve growth (brain-derived neurotrophic factor, glial-cell-derived trophic factor, and nerve growth factor), interleukin 1β, tumor necrosis factor, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), malondialdehyde (MDA), glial fibrillary acidic protein (GFAP), and microglial CD11b in AD rats. And activities of SOD, MDA, and GSH-Px were ameliorated by VO. The neurotrophic factors GFAP and microglial CD11b were noticeably improved in histopathologic changes. These data suggested that VO from SCS had potential activities for the prevention and treatment of AD.

Improvement of Cisplatin-induced renal dysfunction by Schisandra chinensis stems via anti-inflammation and anti-apoptosis effects

ETHNOPHARMACOLOGICAL RELEVANCE

Schisandra chinensis (Turcz.) Baill is a frequently used traditional Chinese medicine, and modern pharmacological research has proven that S. chinensis has antioxidant, anti-hepatotoxity, anti-inflammatory, and anti-nephrotoxic effects. Cisplatin is widely used as antineoplastic drug at present, but the clinical application is limited owing to its nephrotoxicity.

AIM OF THE STUDY

To demonstrate the renoprotective activity of the extract of the stems of S. chinensis (SCE) in mice established by cisplatin-triggering acute kidney injury (AKI). The possible molecular mechanism of nephroprotection exhibited by SCE was evaluated for the first time.

MATERIALS AND METHODS

Mice in SCE groups were pre-treated with SCE for 10 consecutive days, and on 7th day 1 h after final administration, following intraperitoneal injection of cisplatin with 20 mg/kg was treated to cisplatin group and SCE groups. On the 10th day, renal function, histopathological change, and oxidative stress markers were investigated.

RESULTS

Renal oxidative stress level characterized by elevated heme oxygenase 1 (HO-1), cytochrome P450 E1 (CYP2E1) and 4-hydroxynonenal (4-HNE) expression was obviously reduced by SCE pre-treatment. In addition, SCE was found to suppress inflammatory response through the reduction of nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) expression and nuclear factor-kappa B (NF-κB) p65 activation. SCE treatment also inhibited activation of apoptotic pathways through down-regulating Bax, cleaved caspase-3, 8, 9 and up-regulating Bcl-2 expression levels.

CONCLUSION

These findings illustrated that SCE possessed powerful protective effect on AKI caused by cisplatin via amelioration of oxidative stress, inflammation and apoptosis.

Schisandrin B alleviates acute oxidative stress via modulation of the Nrf2/Keap1-mediated antioxidant pathway

Schisandrin B (Sch B), one of the main effective components of the dried fruit of Schisandra chinensis, protects neurons from oxidative stress in the central nervous system. Here we investigated the neuroprotective effect of Sch B against damage caused by acute oxidative stress and attempted to define the possible mechanisms. Using the elevated plus maze and open field test, we found that forced swimming, an acute stressor, significantly induced anxiety-like behavior that was alleviated by oral Sch B treatment. In addition, the Sch B treatment reduced toxicity, malondialdehyde levels, and production of reactive oxygen species, an important factor for neuron damage. Antioxidants under the control of the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway, such as superoxide dismutase and glutathione, were significantly increased by Sch B treatment. Moreover, a higher percentage of intact cells in the amygdala of treated mice, revealed by Nissl staining, further verified the neuroprotective effect of Sch B. Several proteins, such as Nrf2 and its endogenous inhibitor Kelch-like ECH-associated protein 1 (Keap1), were abnormally expressed in mice subjected to forced swimming, but this abnormal expression was significantly reversed by Sch B treatment. Our results suggest that Sch B may be a potential therapeutic agent against anxiety associated with oxidative stress. The possible mechanism is neuroprotection through enhanced antioxidant activity.

Xiaoqinglong Decoction Attenuates Chronic Obstructive Pulmonary Disease in Rats via Inhibition of Autophagy

Effective treatment for chronic obstructive pulmonary disease (COPD) and knowledge of the underlying mechanism are urgently required. Xiaoqinglong decoction (XQL) is widely used to treat COPD in Traditional Chinese Medicine, but the mechanism remains unclear. In this study, we tested the hypothesis that XQL ameliorates COPD via inhibition of autophagy in lung tissue on a rat model. Rats were divided into five groups, namely, Control group, COPD group, COPD + XQL group, COPD + Rapamycin group, and COPD + XQL + Rapamycin group. Pathological changes on cellular and molecular levels, apoptosis reflected by TdT-mediated dUTP Nick-End Labeling (TUNEL) assay, and autophagy represented by LC3II/LC3I ratio and p62 level were investigated for each group. Compared with the Control group, COPD rats exhibited structural changes and activated inflammation in the lung tissue, together with enhanced apoptosis and elevated autophagy biomarkers. XQL treatment significantly ameliorated these changes, while rapamycin augmented them. These data altogether confirmed the involvement of autophagy in the pathogenesis of COPD and suggested that XQL attenuates COPD via inhibition of autophagy.

A Molecular Basis for the Inhibition of Transient Receptor Potential Vanilloid Type 1 by Gomisin A

Transient receptor potential (TRP) channel has critical actions as conditional sensors in primary afferent neurons. We studied the regulatory action of gomisin A on TRPV1 channel current in this report. Schisandra chinensis contains bioactive compounds such as the gomisin derivatives and their related compounds. Coapplication with gomisin A inhibited the capsaicin-mediated inward peak current. This inhibitory effect of gomisin A on capsaicin-induced inward current showed concentration-dependence and was reversible. The half maximal inhibitory concentration of gomisin A was 62.7 ± 8.4 µM. In addition, this inhibition occurred in a noncompetition regulation mode and voltage insensitive manner. Furthermore, molecular docking studies of gomisin A on TRPV1 showed that it interacted predominantly with residues at cavities in the segments 1 and 2 of each subunit. Four potential binding sites for this ligand in the extracellular region at sensor domain of TRPV1 channel were identified. Point mutagenesis studies were undertaken, and gomisin A potency decreased for both the Y453A and N467A mutants. The double mutation of Y453 and N467 significantly attenuated inhibitory effects by gomisin A. In summary, this study revealed the molecular basis for the interaction between TRPV1 and gomisin A and provides a novel potent interaction ligand.

Protective effects of Schisandrin B on cigarette smoke-induced airway injury in mice through Nrf2 pathway

Schisandrin B (SchB), a dibenzocyclooctadiene derivative isolated from Schisandra chinensis, has been reported to have anti-inflammatory effects. However, the protective effects of SchB on cigarette smoke (CS)-induced lung inflammation remain unclear. This study was to investigate the effects of SchB on CS-induced lung inflammation in mice. The mice were exposed to CS to develop lung inflammation. SchB was given 1h before CS exposure daily for five consecutive days. The levels of inflammatory mediators TNF-α, IL-1β, and IL-6 in bronchoalveolar lavage fluid (BALF) were measured in this study. SOD, GSH, MPO and MDA contents were also detected. Furthermore, the expression of Nrf-2 and NF-κB were detected by western blot analysis. Histopathological analyses showed that SchB had protective effects against CS-induced lung inflammation. The levels of inflammatory mediators TNF-α, IL-1β, and IL-6 in BALF were also inhibited by SchB. CS-induced MPO activity and MDA content were inhibited by SchB. The levels of SOD and GSH were up-regulated by SchB. SchB significantly inhibited CS-induced NF-κB activation and up-regulated the expression of Nrf2 and HO-1. In conclusion, these data suggest that SchB protects against CS-induced lung inflammation by activating Nrf2 and inhibiting NF-κB signaling pathway.

Activation inhibitors of nuclear factor kappa B protect neurons against the NMDA-induced damage in the rat retina

We reported that high-mobility group Box-1 (HMGB1) was involved in excitoneurotoxicity in the retina. HMGB1 is known to activate nuclear factor kappa B (NF-κB). However, the role of NF-κB in excitotoxicity is still controversial. Here, we demonstrated that NF-κB activation induced by NMDA led to the retinal neurotoxicity. Male Sprague-Dawley rats were used, and NMDA (200 nmol/eye) and bovine HMGB1 (15 μg/eye) were intravitreally injected. Triptolide (500 pmol/eye), BAY 11-7082 (500 pmol/eye), and IMD-0354 (7.5 nmol/eye), NF-κB inhibitors, were co-injected with NMDA or HMGB1. Retinal sections were obtained seven days after intravitreal injection. Cell loss in the ganglion cell layer was observed in the HMGB1- and the NMDA-treated retina. All of the NF-κB inhibitors used in this study reduced the damage. BAY 11-7082 reduced the expression of phosphorylated NF-κB 12 h after NMDA injection, upregulation of GFAP immunoreactivity induced by NMDA 12 and 48 h after NMDA injection, and the number of TUNEL-positive cells 48 h after NMDA injection. The results suggest that NF-κB activation is one of the mechanisms of the retinal neuronal death that occurs 48 h after NMDA injection or later. Prevention of NF-kB activation is a candidate for the treatment of retinal neurodegeneration associated with excitotoxicity.

Schisandra chinensis Stem Ameliorates 3-Nitropropionic Acid-Induced Striatal Toxicity via Activation of the Nrf2 Pathway and Inhibition of the MAPKs and NF-κB Pathways

The beneficial value of the stems of Schisandra chinensis (SSC) in neurological diseases is unclear. We examined whether SSC aqueous extract (SSCE) alleviates striatal toxicity in a 3-nitropropionic acid (3-NPA)-induced mouse model of Huntington's disease (HD). SSCE (75, 150, or 300 mg/kg/day, p.o.) was given daily before or after 3-NPA treatment. Pre- and onset-treatment with SSCE displayed a significant protective effect and pretreatment was more effective as assessed by neurological scores and survival rate. These effects were related to reductions in mean lesion area, cell death, succinate dehydrogenase activity, microglial activation, and protein expression of inflammatory factors including interleukin (IL)-1β, IL-6, tumor necrosis factor-alpha, inducible nitric oxide synthase, and cyclooxygenase-2 in the striatum after 3-NPA treatment. Pretreatment with SSCE stimulated the nuclear factor erythroid 2-related factor 2 pathway and inhibited phosphorylation of the mitogen-activated protein kinase and nuclear factor-kappa B signaling pathways in the striatum after 3-NPA treatment. The gomisin A and schizandrin components of SSCE significantly reduced the neurological impairment and lethality induced by 3-NPA treatment. These results indicate for the first time that SSCE may effectively prevent 3-NPA-induced striatal toxicity during a wide therapeutic time window through anti-oxidative and anti-inflammatory activities. SSCE has potential value in preventive and therapeutic strategies for HD-like symptoms.

Advanced glycation end products decrease collagen I levels in fibroblasts from the vaginal wall of patients with POP via the RAGE, MAPK and NF-κB pathways

The present study was carried out to observe the impact of advanced glycation end products (AGEs) on collagen I derived from vaginal fibroblasts in the context of pelvic organ prolapse (POP), and explore the downstream effects on MAPK and nuclear factor-κB (NF-κB) signaling. After treating primary cultured human vaginal fibroblasts (HVFs) derived from POP and non-POP cases with AGEs, cell counting was carried out by sulforhodamine B. The expression levels of collagen I, receptor of advanced glycation end products (RAGE), matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of metalloproteinase-1 (TIMP-1) were detected by western blot analysis and PCR. RAGE, MAPK and NF-κB were molecularly and pharmacologically-inhibited by siRNA, SB203580 and PDTC, respectively, and downstream changes were detected by western blot analysis and PCR. Inhibition of HVF proliferation by AGEs occurred more readily in POP patients than that noted in the controls. After treatment with AGEs, collagen I levels decreased and MMP-1 levels increased to a greater extent in the HVFs of POP than that noted in the controls. During this same period, RAGE and TIMP-1 levels remained stable. Following treatment with AGEs and RAGE pathway inhibitors by siRNA, SB203580 and PDTC, the impact induced by AGEs was diminished. The inhibition of p-p38 MAPK alone was not able to block the promoting effect of AGEs on the levels of NF-κB, which suggests that AGEs may function through other pathways, as well as p-p38 MAPK. On the whole, this study demonstrated that AGEs inhibited HVF proliferation in POP cases and decreased the expression of collagen I through RAGE and/or p-p38 MAPK and NF-κB-p-p65 pathways. Our results provide important insights into the collagen I metabolism in HVFs in POP.

Schisandrin B attenuates CCl4-induced liver fibrosis in rats by regulation of Nrf2-ARE and TGF-β/Smad signaling pathways

Liver fibrosis is a major pathological feature of chronic liver diseases and there is no effective therapy program at present. Schisandrin B (Sch B) is the major bioactive ingredient of Schisandra chinensis, with antioxidative, anti-inflammatory, antitumor, and hepatoprotective properties. This study aimed to investigate the protective effect and related molecular mechanism of Sch B against carbon tetrachloride (CCl₄)-induced liver fibrosis in rats. The in vivo therapeutic effect of Sch B on liver fibrosis induced by CCl₄ was examined in rats. In vitro, rat hepatic stellate cells (HSC-T6) were used to assess the effect of Sch B on the activation of HSCs. Sch B effectively attenuated liver damage and progression of liver fibrosis in rats, as evidenced by improved liver function and decreased collagen deposition. The effects of Sch B were associated with attenuating oxidative stress by activating nuclear factor-erythroid 2-related factor 2 (Nrf2)-mediated antioxidant signaling and suppressing HSC activation by inhibiting the transforming growth factor-β (TGF-β)/Smad signaling pathway. In an in vitro study, it was shown that Sch B inhibited TGF-β-induced HSC activation. Finally, Sch B significantly inhibited TGF-β1-stimulated phosphorylation of Smad and signaling of mitogen-activated protein kinases. This study demonstrates that Sch B prevents the progression of liver fibrosis by the regulation of Nrf2-ARE and TGF-β/Smad signaling pathways, and indicates that Sch B can be used for the treatment of liver fibrosis.

Arrestins contribute to amyloid beta-induced cell death via modulation of autophagy and the α7nAch receptor in SH-SY5Y cells

Amyloid β-protein (Aβ) is believed to contribute to the development of Alzheimer’s disease (AD). Here we showed that Aβ_25-35 rapidly caused activation of autophagy, subsequently leading to reduction of autophagy associated with cellular apoptosis. Further investigation revealed that the accumulation of β-arrestin 1 (ARRB1) caused by Aβ_25-35 contributed to the induction of autophagic flux. The depletion of ARRB1 led to decreases in the expression of LC3B, Atg7, and Beclin-1, which are essential for the initiation of autophagy. ARRB1 depletion also reduced downstream ERK activity and promoted Aβ_25-35-induced cell death. As with ARRB1, transient upregulation of ARRB2 by Aβ_25-35 was observed after short treatment durations, whereas genetic reduction of ARRB2 caused a marked increase in the expression of the α7nAch receptor at the cell surface, which resulted in partial reversal of Aβ_25-35-induced cell death. Although expression of both ARRB1 and ARRB2 was reduced in serum from patients with AD, the levels of ARRB1 were much lower than those of ARRB2 in AD. Thus, our findings indicate that ARRB1/2 play different roles in Aβ_25-35 cytotoxicity, which may provide additional support for exploring the underlying molecular mechanism of AD.

Metal ions influx is a double edged sword for the pathogenesis of Alzheimer's disease

Alzheimer's disease (AD) is a common form of dementia in aged people, which is defined by two pathological characteristics: β-amyloid protein (Aβ) deposition and tau hyperphosphorylation. Although the mechanisms of AD development are still being debated, a series of evidence supports the idea that metals, such as copper, iron, zinc, magnesium and aluminium, are involved in the pathogenesis of the disease. In particular, the processes of Aβ deposition in senile plaques (SP) and the inclusion of phosphorylated tau in neurofibrillary tangles (NFTs) are markedly influenced by alterations in the homeostasis of the aforementioned metal ions. Moreover, the mechanisms of oxidative stress, synaptic plasticity, neurotoxicity, autophagy and apoptosis mediate the effects of metal ions-induced the aggregation state of Aβ and phosphorylated tau on AD development. More importantly, imbalance of these mechanisms finally caused cognitive decline in different experiment models. Collectively, reconstructing the signaling network that regulates AD progression by metal ions may provide novel insights for developing chelators specific for metal ions to combat AD.

Recuperating Lung Decoction Attenuates the Oxidative Stress State of Chronic Obstructive Pulmonary Disease by Inhibiting the MAPK/AP-1 Signal Pathway and Regulating γ-GCS

Purpose/Objective. To evaluate the effects of Recuperating Lung Decoction (RLD) on the indices of oxidative stress in a rat model of COPD and detect the indices of the MAPK/AP-1/γ-GCS signal pathway for a further survey of the possible targeting site of RLD. Methods/Materials. The rats of COPD were treated with RLD. The protein levels of glutathione (GSH), oxidized glutathione (GSSG), 8-hydroxy-2-deoxyguanosine (8-OHdG), and 4-hydroxynonenal (4-HNE) were measured. In addition, the levels of key signaling molecules (extracellular signal-regulated kinases [ERK], the c-jun N-terminal kinase [JNKs signal pathway], and p38 MAP kinase [p38MAPK], AP-1 proteins [C-fos, C-jun], and γ-glutamyl-cysteine synthetase [γ-GCS-h]) of the MAPK/AP-1/γ-GCS-h signal pathway were assessed. Results. After treatment, the protein level of GSH and the ratio of GSH/GSSG were increased and the amounts of 8-OHdG and 4-HNE were decreased significantly in lung tissues when compared with the nontreated COPD group. Further results showed that the RLD could effectively inhibit the MAPK pathway by inactivation of p38MAPK and ERK and could also downregulate the AP-1 and the γ-GCS-h genes expressions in both protein and mRNA levels. Conclusion. RLD might improve the state of oxidative stress by downregulation of the expression of γ-GCS-h gene by inhibition of the MAPK/AP-1 pathway, thereafter enhancing the ability of antioxidation in COPD.