Neuroprotective Effects of Anthraquinones from Rhubarb in Central Nervous System Diseases

The Water Extract of Rhubarb Prevents Ischemic Stroke by Regulating Gut Bacteria and Metabolic Pathways

Rhubarb (RR), Chinese name Dahuang, is commonly used in the treatment of ischemic stroke (IS). However, its potential mechanism is not fully elucidated. This study intended to verify the effect of RR on IS and investigate the possible mechanism of RR in preventing IS. IS in male rats was induced by embolic middle cerebral artery occlusion (MCAO) surgery, and drug administration was applied half an hour before surgery. RR dramatically decreased the neurological deficit scores, the cerebral infarct volume, and the cerebral edema rate, and improved the regional cerebral blood flow (rCBF) and histopathological changes in the brain of MCAO rats. The 16S rRNA analysis showed the harmful microbes such as Fournierella and Bilophila were decreased, and the beneficial microbes such as Enterorhabdus, Defluviitaleaceae, Christensenellaceae, and Lachnospira were significantly increased, after RR pretreatment. 1H-nuclear magnetic resonance (1H-NMR) was used to detect serum metabolomics, and RR treatment significantly changed the levels of metabolites such as isoleucine, valine, N6-acetyllysine, methionine, 3-aminoisobutyric acid, N, N-dimethylglycine, propylene glycol, trimethylamine N-oxide, myo-inositol, choline, betaine, lactate, glucose, and lipid, and the enrichment analysis of differential metabolites showed that RR may participate in the regulation of amino acid metabolism and energy metabolism. RR exerts the role of anti-IS via regulating gut bacteria and metabolic pathways.

Brain and serum metabolomic studies reveal therapeutic effects of san hua decoction in rats with ischemic stroke

San Hua Decoction (SHD) is a traditional four-herbal formula that has long been used to treat stroke. Our study used a traditional pharmacodynamic approach combined with systematic and untargeted metabolomics analyses to further investigate the therapeutic effects and potential mechanisms of SHD on ischemic stroke (IS). Male Sprague-Dawley rats were randomly divided into control, sham-operated, middle cerebral artery occlusion reperfusion (MCAO/R) model and SHD groups. The SHD group was provided with SHD (7.2 g/kg, i.g.) and the other three groups were provided with equal amounts of purified water once a day in the morning for 10 consecutive days. Our results showed that cerebral infarct volumes were reduced in the SHD group compared with the model group. Besides, SHD enhanced the activity of SOD and decreased MDA level in MCAO/R rats. Meanwhile, SHD could ameliorate pathological abnormalities by reducing neuronal damage, improving the structure of damaged neurons and reducing inflammatory cell infiltration. Metabolomic analysis of brain and serum samples with GC-MS techniques revealed 55 differential metabolites between the sham and model groups. Among them, the levels of 12 metabolites were restored after treatment with SHD. Metabolic pathway analysis showed that SHD improved the levels of 12 metabolites related to amino acid metabolism and carbohydrate metabolism, 9 of which were significantly associated with disease. SHD attenuated brain inflammation after ischemia-reperfusion. The mechanisms underlying the therapeutic effects of SHD in MCAO/R rats are related to amino acid and carbohydrate metabolism.

Quality assessment of Rheum species cultivated in Japan by focusing on M2 polarization of microglia

In traditional Japanese medicine, Rhei Rhizoma is used as a purgative, blood stasis-resolving and antipsychotic drug. The latter two properties are possibly related to anti-inflammatory effects. Microglia regulate inflammation in the central nervous system. M1 microglia induce inflammation, while M2 microglia inhibit inflammation and show neurotrophic effects. This study investigated the effects from water extracts of roots of cultivated Rheum species in Nagano Prefecture, Japan (strain C, a related strain to a Japanese cultivar, 'Shinshu-Daio'; and strain 29, a Chinese strain) and 3 kinds of Rhei Rhizoma available in the Japanese market, and also examined their constituents on the polarization of cultured microglia. All extracts significantly decreased M1 microglia, and strains C and 29 significantly increased M2 microglia. Furthermore, the extracts of both strains significantly increased the M2/M1 ratio. Among the constituents of Rhei Rhizoma, ( +)-catechin (2), resveratrol 4'-O-β-D-(6″-O-galloyl) glucopyranoside (5), isolindleyin (8), and physcion (15) significantly increased the M2/M1 ratio. The contents of the constituents in water extract of each strain were quantified using HPLC. The extracts of strains C and 29 contained relatively large amounts of 2 and 5; and 2, 8, and 15, respectively. This study showed the water extracts of roots of cultivated Rheum strains in Japan had the effects of M2 polarization of microglia, suggesting that these strains become the candidate to develop anti-inflammatory Rhei Rhizoma. Moreover, the suitable chemical composition to possess anti-inflammatory activity in the brain was clarified for the future development of new type of Rhei Rhizoma.

Chrysophanol exerts a protective effect against Aβ25-35-induced Alzheimer's disease model through regulating the ROS/TXNIP/NLRP3 pathway

BACKGROUND

The primary pathogenic factors of Alzheimer's disease (AD) have been identified as oxidative stress, inflammatory damage, and apoptosis. Chrysophanol (CHR) has a good neuroprotective effect on AD, however, the potential mechanism of CHR remains unclear.

PURPOSE

In this study, we focused on the ROS/TXNIP/NLRP3 pathway to determine whether CHR regulates oxidative stress and neuroinflammation.

METHODS

D-galactose and Aβ_25-35 combination were used to build an in vivo model of AD, and the Y-maze test was used to evaluate the learning and memory function of rats. Morphological changes of neurons in the rat hippocampus were observed using hematoxylin and eosin (HE) staining. AD cell model was established by Aβ_25-35 in PC12 cells. The DCFH-DA test identified reactive oxygen species (ROS). The apoptosis rate was determined using Hoechst33258 and flow cytometry. In addition, the levels of MDA, LDH, T-SOD, CAT, and GSH in serum, cell, and cell culture supernatant were detected by colorimetric method. The protein and mRNA expressions of the targets were detected by Western blot and RT-PCR. Finally, molecular docking was used to further verify the in vivo and in vitro experimental results.

RESULTS

CHR could significantly improve learning and memory impairment, reduce hippocampal neuron damage, and reduce ROS production and apoptosis in AD rats. CHR could improve the survival rate, and reduce the oxidative stress and apoptosis in the AD cell model. Moreover, CHR significantly decreased the levels of MDA and LDH, and increased the activities of T-SOD, CAT, and GSH in the AD model. Mechanically, CHR significantly reduced the protein and mRNA expression of TXNIP, NLRP3, Caspase-1, IL-1β, and IL-18, and increase TRX.

CONCLUSIONS

CHR exerts neuroprotective effects on the Aβ_25-35-induced AD model mainly by reducing oxidative stress and neuroinflammation, and the mechanism may be related to ROS/TXNIP/NLRP3 signaling pathway.

Network pharmacology and in vitro experimental verification to explore the mechanism of Sanhua decoction in the treatment of ischaemic stroke

CONTEXT

Stroke is an illness with high morbidity, disability and mortality that presents a major clinical challenge. Sanhua decoction (SHD) has been widely used to treat ischaemic stroke in the clinic. However, the potential mechanism of SHD remains unknown.

OBJECTIVE

To elucidate the multitarget mechanism of SHD in ischaemic stroke through network pharmacology and bioinformatics analyses.

MATERIALS AND METHODS

Network pharmacology and experimental validation approach was used to investigate the bioactive ingredients, critical targets and potential mechanisms of SHD against ischaemic stroke. Four herbal names of SHD, 'ischemic stroke' or 'stroke' was used as a keyword to search the relevant databases. SH-SY5Y cells were treated with various concentrations of SHD (12.5, 25, 50 or 100 μg/mL) for 4 h, exposed to oxygen and glucose deprivation (OGD) for 1 h, then reoxygenation for 24 h. The cell viability was detected by MTT, the lactate dehydrogenase (LDH) was evaluated by ELISA, and protein expression was detected by western blots.

RESULTS

SHD treatment increased the survival rate from 65.9 ± 4.3 to 85.56 ± 5.7%. The median effective dose (ED₅₀) was 47.1 μg/mL, the LDH decreased from 288.0 ± 12.0 to 122.8 ± 9.1 U/L and the cell apoptosis rate decreased from 33.6 ± 1.8 to 16.3 ± 1.2%. Western blot analysis revealed that SHD increased the levels of p-PI3k, p-Akt and p-CREB1, and decreased the expression of TNF-α and IL-6.

DISCUSSION AND CONCLUSIONS

This study suggests that SHD protects against cerebral ischaemic injury via regulation of the PI3K/Akt/CREB1 and TNF pathways.

Study on chronic toxicity of rhubarb extract in Sprague-Dawley rats

Objective

The purpose of this study was to evaluate the safety of rhubarb extract.

Methods

SD rats were treated with rhubarb extract at 0, 101, 405 and 1620 mg/kg/day for 52 weeks. food consumption and body weights were recorded. Blood and urine samples were collected for serum biochemical evaluation and urinalysis, and organ tissues were collected for histopathological examination.

Results

The rats of 1620 mg/kg group developed diarrhea symptoms with dark brown loose stool after exposure; decreased body weight and increased food consumption were observed in the 1620 mg/kg and 405 mg/kg groups; urine WBC and NIT was significantly increased in the male and female rats of 1620 mg/kg group, and the urine pH was decreased in male rats of 1620 mg/kg group; renal tubular pigmentation was observed in the 1620 mg/kg group.

Conclusion

The NOAEL of rhubarb extract on chronic toxicity (52 weeks) of Sprague-Dawley rats was 101 mg/kg in female and 94 mg/kg in male, and the LOAEL was 408 mg/kg in female and 381 mg/kg in male. The target organ of toxicity was the kidney, and the target cells was tubular epithelial cells.

The progress and prospect of natural components in rhubarb (Rheum ribes L.) in the treatment of renal fibrosis

Background: Renal fibrosis is a key pathological change that occurs in the progression of almost all chronic kidney diseases . CKD has the characteristics of high morbidity and mortality. Its prevalence is increasing each year on a global scale, which seriously affects people’s health and quality of life. Natural products have been used for new drug development and disease treatment for many years. The abundant natural products in R. ribes L. can intervene in the process of renal fibrosis in different ways and have considerable therapeutic prospects.

Purpose: The etiology and pathology of renal fibrosis were analyzed, and the different ways in which the natural components of R. ribes L. can intervene and provide curative effects on the process of renal fibrosis were summarized. Methods: Electronic databases, such as PubMed, Life Science, MEDLINE, and Web of Science, were searched using the keywords ‘R. ribes L.’, ‘kidney fibrosis’, ‘emodin’ and ‘rhein’, and the various ways in which the natural ingredients protect against renal fibrosis were collected and sorted out.

Results: We analyzed several factors that play a leading role in the pathogenesis of renal fibrosis, such as the mechanism of the TGF-β/Smad and Wnt/β-catenin signaling pathways. Additionally, we reviewed the progress of the treatment of renal fibrosis with natural components in R. ribes L. and the intervention mechanism of the crucial therapeutic targets.

Conclusion: The natural components of R. ribes L. have a wide range of intervention effects on renal fibrosis targets, which provides new ideas for the development of new anti-kidney fibrosis drugs.

Emodin Sensitizes Cervical Cancer Cells to Vinblastine by Inducing Apoptosis and Mitotic Death

In recent years, studies on the effects of combining novel plant compounds with cytostatics used in cancer therapy have received considerable attention. Since emodin sensitizes tumor cells to chemotherapeutics, we evaluated changes in cervical cancer cells after its combination with the antimitotic drug vinblastine. Cellular changes were demonstrated using optical, fluorescence, confocal and electron microscopy. Cell viability was assessed by MTT assay. The level of apoptosis, caspase 3/7, Bcl-2 protein, ROS, mitochondrial membrane depolarization, cell cycle and degree of DNA damage were analyzed by flow cytometry. The microscopic image showed indicators characteristic for emodin- and vinblastine-induced mitotic catastrophe, i.e., multinucleated cells, giant cells, cells with micronuclei, and abnormal mitotic figures. These compounds also increased blocking of cells in the G2/M phase, and the generated ROS induced swelling and mitochondrial damage. This translated into the growth of apoptotic cells with active caspase 3/7 and inactivation of Bcl-2 protein and active ATM kinase. Emodin potentiated the cytotoxic effect of vinblastine, increasing oxidative stress, mitotic catastrophe and apoptosis. Preliminary studies show that the combined action of both compounds, may constitute an interesting form of anticancer therapy.

Suitability of Banana and Plantain Fruits in Modulating Neurodegenerative Diseases: Implicating the In Vitro and In Vivo Evidence from Neuroactive Narratives of Constituent Biomolecules

Active principles in plant-based foods, especially staple fruits, such as bananas and plantains, possess inter-related anti-inflammatory, anti-apoptotic, antioxidative, and neuromodulatory activities. Neurodegenerative diseases affect the functionality of the central and peripheral nervous system, with attendant cognitive deficits being hallmarks of these conditions. The dietary constitution of a wide range of bioactive compounds identified in this review further iterates the significance of the banana and plantain in compromising, halting, or preventing the pathological mechanisms of neurological disorders. The neuroprotective mechanisms of these biomolecules have been identified by using protein expression regulation and specific gene/pathway targeting, such as the nuclear and tumor necrosis factors, extracellular signal-regulated and mitogen-activated protein kinases, activator protein-1, and the glial fibrillary acidic protein. This review establishes the potential double-edged neuro-pharmacological fingerprints of banana and plantain fruits in their traditionally consumed pulp and less utilized peel component for human nutrition.

Multi-Targets: An Unconventional Drug Development Strategy for Alzheimer's Disease

Alzheimer's disease (AD) is a progressive neurodegenerative disorder that eventually leads to dementia and death of the patient. Despite the enormous amounts of resources and efforts for AD drug development during the last three decades, no effective treatments have been developed that can slow or halt the progression of the disease. Currently available drugs for treating AD can only improve clinical symptoms temporarily with moderate efficacies. In recent years, the scientific community has realized these challenges and reconsidered the future directions of AD drug development. The most significant recent changes in AD drug development strategy include shifting from amyloid-based targets to other targets, such as tau, and efforts toward better designs for clinical trials. However, most AD drug development is still focused on a single mechanism or target, which is the conventional strategy for drug development. Although multifactorial mechanisms and, on this basis, multi-target strategies have been proposed in recent years, this approach has not been widely recognized and accepted by the mainstream of AD drug development. Here, we emphasize the multifactorial mechanisms of AD and discuss the urgent need for a paradigm shift in AD drug development from a single target to multiple targets, either with the multi-target-directed ligands approach or the combination therapy approach. We hope this article will increase the recognition of the multifactorial nature of AD and promote this paradigm shift. We believe that such a shift will facilitate successful development of effective AD therapies.

Rheum tanguticum Alleviates Cognitive Impairment in APP/PS1 Mice by Regulating Drug-Responsive Bacteria and Their Corresponding Microbial Metabolites

Drugs targeting intestinal bacteria have shown great efficacy for alleviating symptoms of Alzheimer’s disease (AD), and microbial metabolites are important messengers. Our previous work indicated that Rheum tanguticum effectively improved cognitive function and reshaped the gut microbial homeostasis in AD rats. However, its therapeutic mechanisms remain unclear. Herein, this study aimed to elaborate the mechanisms of rhubarb for the treatment of AD by identifying effective metabolites associated with rhubarb-responsive bacteria. The results found that rhubarb reduced hippocampal inflammation and neuronal damage in APP/PS1 transgenic (Tg) mice. 16S rRNA sequencing and metabolomic analysis revealed that gut microbiota and their metabolism in Tg mice were disturbed in an age-dependent manner. Rhubarb-responsive bacteria were further identified by real-time polymerase chain reaction (RT-PCR) sequencing. Four different metabolites reversed by rhubarb were found in the position of the important nodes on rhubarb-responsive bacteria and their corresponding metabolites combined with pathological indicators co-network. Furthermore, in vitro experiments demonstrated o-tyrosine not only inhibited the viabilities of primary neurons as well as BV-2 cells, but also increased the levels of intracellular reactive oxygen species and nitric oxide. In the end, the results suggest that rhubarb ameliorates cognitive impairment in Tg mice through decreasing the abundance of o-tyrosine in the gut owing to the regulation of rhubarb-responsive bacteria. Our study provides a promising strategy for elaborating therapeutic mechanisms of bacteria-targeted drugs for AD.

Alzheimer's Disease and other Tauopathies: Exploring Efficacy of Medicinal Plant-Derived Compounds in Alleviating Tau-Mediated Neurodegeneration

Alzheimer's disease (AD), a major form of dementia, has been reported to affect more than 50 million people worldwide. It is characterized by the presence of amyloid-β (Aβ) plaques and hyperphosphorylated Tau-associated neurofibrillary tangles in the brain. Apart from AD, microtubule (MT)-associated protein Tau is also involved in other neurodegenerative diseases called tauopathies, including Pick's disease, frontotemporal lobar degeneration, progressive supranuclear palsy, and corticobasal degeneration. The recently unsuccessful phase III clinical trials related to Aβ-targeted therapeutic drugs indicated that alternative targets, such as Tau, should be studied to discover more effective and safer drugs. Recent drug discovery approaches to reduce AD-related Tau pathologies are primarily based on blocking Tau aggregation, inhibiting Tau phosphorylation, compensating impaired Tau function with MT-stabilizing agents, and targeting the degradation pathways in neuronal cells to degrade Tau protein aggregates. Owing to several limitations of the currently-available Tau-directed drugs, further studies are required to generate further effective and safer Tau-based disease-modifying drugs. Here, we review the studies that focused on medicinal plant-derived compounds capable of modulating the Tau protein, which is significantly elevated and hyperphosphorylated in AD and other tauopathies. We mainly considered the studies that focused on Tau protein as a therapeutic target. We reviewed several pertinent papers retrieved from PubMed and ScienceDirect using relevant keywords, with a primary focus on the Tau-targeting compounds from medicinal plants. These compounds include indolines, phenolics, flavonoids, coumarins, alkaloids, and iridoids, which have been scientifically proven to be Tau-targeting candidates for the treatment of AD.

Horticultural therapy, nutrition and post-traumatic stress disorder in post-military veterans: developing non-pharmaceutical interventions to complement existing therapeutic approaches

Non-pharmaceutical interventions for veterans living with post-traumatic stress disorder are becoming a more popular way to address some of the social and personal needs identified by this group. Horticultural therapy or growing and eating food together provides several ways to increase mood, improve nutritional status, reduce loneliness and reduce the physical health impacts of mental illnesses such as post-traumatic stress disorder. In this paper we will discuss some of the issues people living with post-traumatic stress disorder might face. We will also provide an overview of the therapeutic effects of these approaches and how they will be applied in a locally identified group.

Therapeutic Potential of Natural Products in Treating Neurodegenerative Disorders and Their Future Prospects and Challenges

Natural products derived from plants, as well as their bioactive compounds, have been extensively studied in recent years for their therapeutic potential in a variety of neurodegenerative diseases (NDs), including Alzheimer's (AD), Huntington's (HD), and Parkinson's (PD) disease. These diseases are characterized by progressive dysfunction and loss of neuronal structure and function. There has been little progress in designing efficient treatments, despite impressive breakthroughs in our understanding of NDs. In the prevention and therapy of NDs, the use of natural products may provide great potential opportunities; however, many clinical issues have emerged regarding their use, primarily based on the lack of scientific support or proof of their effectiveness and patient safety. Since neurodegeneration is associated with a myriad of pathological processes, targeting multi-mechanisms of action and neuroprotection approaches that include preventing cell death and restoring the function of damaged neurons should be employed. In the treatment of NDs, including AD and PD, natural products have emerged as potential neuroprotective agents. This current review will highlight the therapeutic potential of numerous natural products and their bioactive compounds thatexert neuroprotective effects on the pathologies of NDs.

Mechanistic insights into the anti-depressant effect of emodin: an integrated systems pharmacology study and experimental validation

Depression is a complex neuropsychiatric disease involved multiple targets and signaling pathways. Systems pharmacology studies could potentially present a comprehensive molecular mechanism to delineate the anti-depressant effect of emodin (EMO). In this study, we investigated the anti-depressant effects of EMO in the chronic unpredictable mild stress (CUMS) rat model of depression and gained insights into the underlying mechanisms using systems pharmacology and molecular simulation analysis. Forty-three potential targets of EMO for treatment of depression were obtained. GO biological process analysis suggested that the biological functions of these targets mainly involve the regulation of reactive oxygen species metabolic process, response to lipopolysaccharide, regulation of inflammatory response, etc. KEGG pathway enrichment analysis showed that the PI3K-Akt signaling pathway, insulin resistance, IL-17 signaling pathway were the most significantly enriched signaling pathways. The molecular docking analysis revealed that EMO might have a strong combination with ESR1, AKT1 and GSK3B. Immunohistochemical staining and Western blotting showed that 2 weeks' EMO treatment (80 mg/kg/day) reduced depression related microglial activation, neuroinflammation and altered PI3K-Akt signaling pathway. Our findings provide a systemic pharmacology basis for the anti-depressant effects of EMO.

Exploring the mechanism of Radix Rhei Et Rhizome intervention in intracerebral hemorrhage based on systematic pharmacology and proteomics strategy

OBJECTIVE

To explore the mechanism of Radix Rhei Et Rhizome (Dahuang, DH) intervention in intracerebral hemorrhage (ICH) based on systematic pharmacology and proteomics strategy.

METHODS

The systematic pharmacological strategies were utilized to find the bioactive compounds of Radix Rhei Et Rhizome, predict its potential targets, and collect ICH's disease genes; then, the Cytoscape 3.7.1 software was applied for network construction and network topology analysis. After that, in-depth analysis of the proteomics data of Radix Rhei Et Rhizome intervention in ICH was performed to complement and validate the results of systematic pharmacological predictions.

RESULTS

A total of three major networks were constructed in the present study: (1) compound-compound target network of Radix Rhei Et Rhizome, (2) DH-ICH PPI network, (3) proteomics proteins' PPI network. These three major networks have been analyzed by network topology, and several small networks derived (such as signaling pathway networks). The enrichment analysis showed that Radix Rhei Et Rhizome can intervene in several biological process (such as inflammation, smooth muscle proliferation, platelet activation, blood pressure regulation, angiogenesis, hypoxia, and inflammatory response of leukocytes), signaling pathway (such as FoxO signaling pathway, complement and coagulation cascades, cGMP-PKG signaling pathway, and Rap1 signaling pathway), and reactome pathway (such as signaling by interleukins, interleukin-4 and interleukin-13 signaling, nuclear receptor transcription pathway, and platelet activation).

CONCLUSION

Radix Rhei Et Rhizome may intervene in ICH-related biological process, signaling pathway, and reactome pathway found in this research so as to achieve the effect of treating ICH related injuries.

Marine Natural Products: Promising Candidates in the Modulation of Gut-Brain Axis towards Neuroprotection

In recent decades, several neuroprotective agents have been provided in combating neuronal dysfunctions; however, no effective treatment has been found towards the complete eradication of neurodegenerative diseases. From the pathophysiological point of view, growing studies are indicating a bidirectional relationship between gut and brain termed gut-brain axis in the context of health/disease. Revealing the gut-brain axis has survived new hopes in the prevention, management, and treatment of neurodegenerative diseases. Accordingly, introducing novel alternative therapies in regulating the gut-brain axis seems to be an emerging concept to pave the road in fighting neurodegenerative diseases. Growing studies have developed marine-derived natural products as hopeful candidates in a simultaneous targeting of gut-brain dysregulated mediators towards neuroprotection. Of marine natural products, carotenoids (e.g., fucoxanthin, and astaxanthin), phytosterols (e.g., fucosterol), polysaccharides (e.g., fucoidan, chitosan, alginate, and laminarin), macrolactins (e.g., macrolactin A), diterpenes (e.g., lobocrasol, excavatolide B, and crassumol E) and sesquiterpenes (e.g., zonarol) have shown to be promising candidates in modulating gut-brain axis. The aforementioned marine natural products are potential regulators of inflammatory, apoptotic, and oxidative stress mediators towards a bidirectional regulation of the gut-brain axis. The present study aims at describing the gut-brain axis, the importance of gut microbiota in neurological diseases, as well as the modulatory role of marine natural products towards neuroprotection.

Physcion Protects Rats Against Cerebral Ischemia-Reperfusion Injury via Inhibition of TLR4/NF-kB Signaling Pathway

Background

Ischemic stroke (IS) is characterized by the rapid loss of brain function due to ischemia. Physcion has been found to have a neuroprotective effect against cerebral ischemia-reperfusion (I/R) injury. However, the mechanism by which physcion regulates cerebral I/R injury remains largely unknown.

Methods

An oxygen-glucose deprivation/reperfusion (OGD/R) model in SH-SY5Y cells and a rat cerebral ischemia-reperfusion (I/R) model were established, respectively. CCK-8 and flow cytometry assays were used to detect the viability and apoptosis of SH-SY5Y cells. Moreover, enzyme-linked immunosorbent assay (ELISA) was used to measure the levels of SOD, MDA, GSH-Px, TNF-α, IL-1β, IL-6 and IL-10 in the supernatant of SH-SY5Y cells. Meanwhile, Western blot assay was used to detect the expressions of TLR4, p-p65 and p-IκB in SH-SY5Y cells and I/R rats.

Results

In this study, physcion treatment significantly rescued OGD/R-induced neuronal injury. In addition, physcion decreased inflammatory response in SH-SY5Y cells after OGD/R insult, as shown by the decreased levels of the pro-inflammatory factors TNF-α, IL-1β, IL-6 and IL-10. Moreover, physcion attenuated the oxidative stress in OGD/R-treated SY-SY5Y cells, as evidenced by the increased SOD and GSH levels and the decreased ROS and MDA levels. Meanwhile, physcion significantly reduced cerebral infarction, attenuated neuronal injury and apoptosis in I/R rats. Furthermore, physcion markedly decreased the expressions of TLR4, p-NF-κB p65 and p-IκB in the brain tissues of rats subjected to I/R and in SH-SY5Y cells exposed to OGD/R.

Conclusion

In conclusion, our study indicated that physcion protected neuron cells against I/R injury in vitro and in vivo by inhibition of the TLR4/NF-kB pathway; thus, physcion might serve as a promising therapeutic candidate for IS.

A Song of Ice and Fire: Cold and Hot Properties of Traditional Chinese Medicines

The theory of cold and hot properties is the basic theory of traditional Chinese medicines (TCMs) and has been successfully applied to combat human diseases for thousands of years. Although the theory of cold and hot is very important to guide the clinical application of TCMs, this ancient theory remains an enigma for a long time. In recent years, more and more researchers have tried to uncover this ancient theory with the help of modern techniques, and the cold and hot properties of a myriad of TCMs have been studied. However, there is no review of cold and hot properties. In this review, we first briefly introduced the basic theories about cold and hot properties, including how to distinguish between the cold and hot properties of TCMs and the classification and treatment of cold and hot syndromes. Then, focusing on the application of cold and hot properties, we take several important TCMs with cold or hot property as examples to summarize their traditional usage, phytochemistry, and pharmacology. In addition, the mechanisms of thermogenesis and antipyretic effect of these important TCMs, which are related to the cold and hot properties, were summarized. At the end of this review, the perspectives on research strategies and research directions of hot and cold properties were also offered.

Mechanism of Radix Rhei Et Rhizome Intervention in Cerebral Infarction: A Research Based on Chemoinformatics and Systematic Pharmacology

OBJECTIVE

To explore the therapeutic targets, network modules, and coexpressed genes of Radix Rhei Et Rhizome intervention in cerebral infarction (CI), and to predict significant biological processes and pathways through network pharmacology. To explore the differential proteins of Radix Rhei Et Rhizome intervention in CI, conduct bioinformatics verification, and initially explain the possible therapeutic mechanism of Radix Rhei Et Rhizome intervention in CI through proteomics.

METHODS

The TCM database was used to predict the potential compounds of Radix Rhei Et Rhizome, and the PharmMapper was used to predict its potential targets. GeneCards and OMIM were used to search for CI-related genes. Cytoscape was used to construct a protein-protein interaction (PPI) network and to screen out core genes and detection network modules. Then, DAVID and Metascape were used for enrichment analysis. After that, in-depth analysis of the proteomics data was carried out to further explore the mechanism of Radix Rhei Et Rhizome intervention in CI.

RESULTS

(1) A total of 14 Radix Rhei Et Rhizome potential components and 425 potential targets were obtained. The core components include sennoside A, palmidin A, emodin, toralactone, and so on. The potential targets were combined with 297 CI genes to construct a PPI network. The targets shared by Radix Rhei Et Rhizome and CI include ALB, AKT1, MMP9, IGF1, CASP3, etc. The biological processes that Radix Rhei Et Rhizome may treat CI include platelet degranulation, cell migration, fibrinolysis, platelet activation, hypoxia, angiogenesis, endothelial cell apoptosis, coagulation, and neuronal apoptosis. The signaling pathways include Ras, PI3K-Akt, TNF, FoxO, HIF-1, and Rap1 signaling pathways. (2) Proteomics shows that the top 20 proteins in the differential protein PPI network were Syp, Syn1, Mbp, Gap43, Aif1, Camk2a, Syt1, Calm1, Calb1, Nsf, Nefl, Hspa5, Nefh, Ncam1, Dcx, Unc13a, Mapk1, Syt2, Dnm1, and Cltc. Differential protein enrichment results show that these proteins may be related to synaptic vesicle cycle, vesicle-mediated transport in synapse, presynaptic endocytosis, synaptic vesicle endocytosis, axon guidance, calcium signaling pathway, and so on.

CONCLUSION

This study combined network pharmacology and proteomics to explore the main material basis of Radix Rhei Et Rhizome for the treatment of CI such as sennoside A, palmidin A, emodin, and toralactone. The mechanism may be related to the regulation of biological processes (such as synaptic vesicle cycle, vesicle-mediated transport in synapse, presynaptic endocytosis, and synaptic vesicle endocytosis) and signaling pathways (such as Ras, PI3K-Akt, TNF, FoxO, HIF-1, Rap1, and axon guidance).

Promotion of Mitochondrial Protection by Emodin in Methylglyoxal-Treated Human Neuroblastoma SH-SY5Y Cells: Involvement of the AMPK/Nrf2/HO-1 Axis

Mitochondrial dysfunction is part of the mechanism of several human diseases. This negative circumstance may be induced by certain toxicants, as methylglyoxal (MG). MG is a reactive dicarbonyl presenting both endogenous and exogenous sources and is also able to induce protein cross-linking and glycation. Emodin (EM; 1,3,8-trihydroxy-6-methylanthracene-9,10-dione; C₁₅H₁₀O₅) is a cytoprotective agent. Nonetheless, it was not previously demonstrated whether EM would be able to promote mitochondrial protection in cells challenged with MG. Therefore, we investigated here whether and how EM would prevent the MG-induced mitochondrial collapse in the human neuroblastoma SH-SY5Y cells. We found that a pretreatment (for 4 h) with EM at 40 μM prevented the MG-induced mitochondrial dysfunction (i.e., decreased activity of the complexes I and V, reduced adenosine triphosphate levels, and loss of mitochondrial membrane potential) in the SH-SY5Y cells. EM also prevented the redox impairment induced by MG in mitochondrial membranes. Inhibiting the adenosine monophosphate-activated protein kinase (AMPK) or silencing of the nuclear factor erythroid 2-related factor 2 (Nrf2), transcription factor abolished the EM-induced protection. Inhibition of heme oxygenase-1 (HO-1) also blocked the EM-induced mitochondrial protection. Therefore, EM protected the mitochondria by a mechanism dependent on the AMPK/Nrf2/HO-1 signaling pathway in MG-challenged SH-SY5Y cells.

Nguyen D, A. Phan T, M. Hamada S, Panchel R, C. Tam C, H. Kim J, W. Cheng L, M. Land K. The Inhibitory Activity of Anthraquinones against Pathogenic Protozoa, Bacteria, and Fungi and the Relationship to Structure

Plant-derived anthraquinones were evaluated in cell assays for their inhibitory activities against the parasitic protozoa Trichomonas vaginalis human strain G3 that causes the sexually transmitted disease trichomoniasis in women, Tritrichomonas foetus bovine strain D1 that causes sexually transmitted diseases in farm animals (bulls, cows, and pigs), Tritrichomonas foetus-like strain C1 that causes diarrhea in domestic animals (cats and dogs), and bacteria and fungi. The anthraquinones assessed for their inhibitory activity were anthraquinone, aloe-emodin (1,8-dihydroxy-3-hydroxymethylanthraquinone), anthrarufin (1,5-dihydroxyanthraquinone), chrysazin (1,8-dihydroxyanthraquinone), emodin (1,3,8-trihydroxy-6-methylanthraquinone), purpurin (1,2,4-trihydroxyanthraquinone), and rhein (1,8-dihydroxy-3-carboxyanthraquinone). Their activities were determined in terms of IC₅₀ values, defined as the concentration that inhibits 50% of the cells under the test conditions and calculated from linear dose response plots for the parasitic protozoa, and zone of inhibition for bacteria and fungi, respectively. The results show that the different substituents on the anthraquinone ring seem to influence the relative potency. Analysis of the structure–activity relationships in protozoa indicates that the aloe-emodin and chrysazin with the highest biological activities merit further study for their potential to help treat the diseases in women and domestic and farm animals. Emodin also exhibited antifungal activity against Candida albicans. The suggested mechanism of action and the additional reported beneficial biological properties of anthraquinones suggest that they have the potential to ameliorate a broad spectrum of human diseases.

Huang-Pu-Tong-Qiao Formula Ameliorates Tau Phosphorylation by Inhibiting the CaM-CaMKIV Pathway

Alzheimer's disease (AD) is a complex neurodegenerative disease. It is a chronic, lethal disease in which brain function is severely impaired and neuronal damage is irreversible. Huang-Pu-Tong-Qiao (HPTQ), a formula from traditional Chinese medicine, has been used in the clinical treatment of AD for many years, with remarkable effects. However, the neuroprotective mechanisms of HPTQ in AD have not yet been investigated. In the present study, we used AD models in vivo and in vitro, to investigate both the neuroprotective effect of HPTQ water extracts (HPTQ-W) and the potential mechanisms of this action. For the in vivo study, after HPTQ intervention, the Morris water maze test was used to examine learning and memory in rats. Transmission electron microscopy and immunofluorescence methods were then used to investigate neuronal damage. For the in vitro experiments, rat primary hippocampal neurons were cultured and cell viability was examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide. Additionally, mRNA levels of CaM, CaMKK, CaMKIV, and tau were examined using qRT-PCR, and protein expression of CaM, CaMKK, p-CaMKIV, and p-tau were examined using western blot. In vivo, we revealed that HPTQ significantly improved learning and memory deficits and attenuated neuronal damage in the AD rat model. Furthermore, in vitro results showed that HPTQ significantly increased cell viability in the AD cell model. We also demonstrated that HPTQ significantly decreased the mRNA levels of CaM, CaMKK, CaMKIV, and tau and significantly decreased the protein expressions of CaM, CaMKK, p-CaMKIV, and p-tau. In conclusion, our results indicated that HPTQ improved cognition and ameliorated neuronal damage in AD models and implicated a reduction in tau phosphorylation caused by inhibition of the CaM-CaMKIV pathway as a possible mechanism.

Neuroprotective Effects of Emodin against Ischemia/Reperfusion Injury through Activating ERK-1/2 Signaling Pathway

Background: Stroke is one of the leading causes of death and disability worldwide and places a heavy burden on the economy in our society. Current treatments, such as the use of thrombolytic agents, are often limited by a narrow therapeutic time window. However, the regeneration of the brain after damage is still active days, even weeks, after stroke occurs, which might provide a second window for treatment. Emodin, a traditional Chinese medicinal herb widely used to treat acute hepatitis, has been reported to possess antioxidative capabilities and protective effects against myocardial ischemia/reperfusion injury. However, the underlying mechanisms and neuroprotective functions of Emodin in a rat middle cerebral artery occlusion (MCAO) model of ischemic stroke remain unknown. This study investigates neuroprotective effects of Emodin in ischemia both in vitro and in vivo. Methods: PC12 cells were exposed to oxygen-glucose deprivation to simulate hypoxic injury, and the involved signaling pathways and results of Emodin treatment were evaluated. The therapeutic effects of Emodin in ischemia animals were further investigated. Results: Emodin reduced infarct volume and cell death following focal cerebral ischemia injury. Emodin treatment restored PC12 cell viability and reduced reactive oxygen species (ROS) production and glutamate release under conditions of ischemia/hypoxia. Emodin increased Bcl-2 and glutamate transporter-1 (GLT-l) expression but suppressed activated-caspase 3 levels through activating the extracellular signal-regulated kinase (ERK)-1/2 signaling pathway. Conclusion: Emodin induced Bcl-2 and GLT-1 expression to inhibit neuronal apoptosis and ROS generation while reducing glutamate toxicity via the ERK-1/2 signaling pathway. Furthermore, Emodin alleviated nerve cell injury following ischemia/reperfusion in a rat MCAO model. Emodin has neuroprotective effects against ischemia/reperfusion injury both in vitro and in vivo, which may be through activating the ERK-1/2 signaling pathway.

Virtual Screening of the Multi-pathway and Multi-gene Regulatory Molecular Mechanism of Dachengqi Decoction in the Treatment of Stroke Based on Network Pharmacology

BACKGROUND

Stroke is ranked second among diseases that cause mortality worldwide. Owing to its complicated pathogenesis, no satisfactory treatment strategies for stroke are available. Dachengqi decoction (DCQD), a traditional Chinese herbal medicine, has been widely used in China for a long time, as it has a good effect on stroke. However, the molecular mechanism underlying this effect of DCQD is unclear.

OBJECTIVE

In the present study, we aimed to reveal and explore the multi-pathway and multi-gene regulatory molecular mechanism of Dachengqi decoction in the treatment of stroke.

METHODS

In this study, a network pharmacology method, in combination with oral bioavailability prediction and drug-likeness evaluation, was employed to predict the active ingredients of DCQD. The target genes of the active components and the traced pathways related to these target genes were predicted. Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed using clusterProfiler software package on the R platform and ClueGo+CluePedia plug-ins. Finally, the key DCQD targets were verified using the Gene Expression Omnibus (GEO) dataset.

RESULTS AND DISCUSSION

According to the ADME model, 52 active components were screened from 296 active components of DCQD. After prediction and screening, 215 stroke-related targets were obtained and analyzed via GO and KEGG analyses. GO analysis showed that DCQD targets were mainly involved in the regulation of oxidative stress, lipid metabolism, inflammation, and other biological processes. KEGG pathway analysis further revealed pathways involved in stroke, such as arachidonic acid metabolic, HIF-1 signaling pathway, estrogen signaling pathway, MAPK signaling pathway, PI3K-Akt signaling pathway, platelet activation pathway, VEGF signaling pathway, and cAMP signaling pathway. Network analysis revealed that DCQD might be involved in the regulation of lipid metabolism, blood pressure, inflammation, angiogenesis, neuroprotection, platelet aggregation, apoptosis, and oxidation in stroke treatment. GEO dataset analysis showed that DCQD's therapeutic effects might be exerted via the bidirectional regulation principle.

CONCLUSION

Based on the methods of network pharmacology and GEO analysis, it was found that, during stroke treatment, DCQD regulates and controls multiple genes and multiple pathways in a synergistic manner, providing a new strategy for stroke treatment.