Matrine promotes oligodendrocyte development in CNS autoimmunity through the PI3K/Akt signaling pathway

Bioinformatics analysis of the potential receptor and therapeutic drugs for Alzheimer's disease with comorbid Parkinson's disease

Background

Now, there are no sensitive biomarkers for improving Alzheimer's disease (AD) and comorbid Parkinson's disease (PD). The aim of the present study was to analyze differentially expressed genes (DEGs) in brain tissue from AD and PD patients via bioinformatics analysis, as well as to explore precise diagnostic and therapeutic targets for AD and comorbid PD.

Methods

GFE122063 and GSE7621 data sets from GEO in NCBI, were used to screen differentially expressed genes (DEGs) for AD and PD, and identify the intersected genes, respectively. Intersected genes were analyzed by Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. Then, STRING site and Cytoscape were used to construct a protein-protein interaction (PPI) network, CytoNCA algorithm to analyze and evaluate centrality, Mcode plug-in to analyze module, and Cytohubba to screen key genes. Combined GO-KEGG enrichment analysis with Cytoscape algorithm to screen the key gene in AD complicated with PD. Then, the DEGs for AD and PD were imported into the Association Map (CMap) online platform to screen out the top 10 small molecule drugs, and using molecular docking techniques to evaluate the interactions between small molecule drugs and key genes receptors.

Results

In total, 231 upregulated genes and 300 downregulated genes were identified. GO analysis revealed that the DEGs were highly enriched in signal transduction, and KEGG analysis revealed that the DEGs were associated with the MAPK and PI3K-Akt signaling pathways. Epidermal growth factor receptor (EGFR) was identified as a potential receptor gene in AD and comorbid PD. EGFR was upregulated in both AD and PD, and the proteins that interact with EGFR were enriched in the Ras/Raf/MAPK and PI3K/Akt signaling pathways. Semagacestat was identified as a drug with therapeutic potential for treating AD complicated with PD. There was a high binding affinity between semagacestat and EGFRNTD, with seven hydrogen bonds and one hydrophobic bond.

Discussion

Semagacestat may improve the health of patients with AD complicated with PD through the regulation of the Ras/Raf/MAPK and PI3K/Akt signaling pathways by EGFR, providing evidence supporting the structural modification of semagacestat to develop a more effective drug for treating AD complicated with PD.

A review on plant-based remedies for the treatment of multiple sclerosis

Multiple sclerosis (MS) is a complex autoimmune disease of central nervous system, which is degenerative in nature usually appears between 20-40years of age. The exact cause of MS is still not clearly known. Loss of myelin sheath and axonal damage are the main features of MS that causes induction of inflammatory process and blocks free conduction of impulses. Till date FDA has approved 18 drugs to treat or modify MS symptoms. These medicines are disease-modifying in nature directed to prevent relapses or slow down the progression of disease. The use of the synthetic drug over an extended period causes undesirable effects that prompt us to look at Mother Nature. Complementary and alternative medicine involves the use of medicinal plants as an alternative to the existing modern medical treatment. However, modern drugs cannot be replaced completely with medicinal plants, but the two types of drugs can be used harmoniously with later one can be added as an adjuvant to the existing treatment. These medicinal plants have the potential to prevent progression and improve the symptoms of MS. Various plants such like Nigella sativa, ginger, saffron, pomegranate, curcumin, resveratrol, ginsenoside have been tested as therapeutics for many neurodegenerative diseases. The purpose of this write-up is to make information available about medicinal plants in their potential to treat or modify the symptoms of MS. Chronically ill patients tend to seek medicinal plants as they are easily available and there is a general perception about these medicines of having fewer undesirable effects.

Matrine exerts its neuroprotective effects by modulating multiple neuronal pathways

Recent evidence suggests that misfolding, clumping, and accumulation of proteins in the brain may be common causes and pathogenic mechanism for several neurological illnesses. This causes neuronal structural deterioration and disruption of neural circuits. Research from various fields supports this idea, indicating that developing a single treatment for several severe conditions might be possible. Phytochemicals from medicinal plants play an essential part in maintaining the brain's chemical equilibrium by affecting the proximity of neurons. Matrine is a tetracyclo-quinolizidine alkaloid derived from the plant Sophora flavescens Aiton. Matrine has been shown to have a therapeutic effect on Multiple Sclerosis, Alzheimer's disease, and various other neurological disorders. Numerous studies have demonstrated that matrine protects neurons by altering multiple signalling pathways and crossing the blood-brain barrier. As a result, matrine may have therapeutic utility in the treatment of a variety of neurocomplications. This work aims to serve as a foundation for future clinical research by reviewing the current state of matrine as a neuroprotective agent and its potential therapeutic application in treating neurodegenerative and neuropsychiatric illnesses. Future research will answer many concerns and lead to fascinating discoveries that could impact other aspects of matrine.

Effect of β-hydroxybutyrate on behavioral alterations, molecular and morphological changes in CNS of multiple sclerosis mouse model

Multiple sclerosis (MS) is a chronic inflammatory and degenerative disease of central nervous system (CNS). Aging is the most significant risk factor for the progression of MS. Dietary modulation (such as ketogenic diet) and caloric restriction, can increase ketone bodies, especially β-hydroxybutyrate (BHB). Increased BHB has been reported to prevent or improve age-related disease. The present studies were performed to understand the therapeutic effect and potential mechanisms of exogenous BHB in cuprizone (CPZ)-induced demyelinating model. In this study, a continuous 35 days CPZ mouse model with or without BHB was established. The changes of behavior function, pathological hallmarks of CPZ, and intracellular signal pathways in mice were detected by Open feld test, Morris water maze, RT-PCR, immuno-histochemistry, and western blot. The results showed that BHB treatment improved behavioral performance, prevented myelin loss, decreased the activation of astrocyte as well as microglia, and up-regulated the neurotrophin brain-derived neurotrophic factor in both the corpus callosum and hippocampus. Meanwhile, BHB treatment increased the number of MCT1+ cells and APC+ oligodendrocytes. Furthermore, the treatment decreased the expression of HDAC3, PARP1, AIF and TRPA1 which is related to oligodendrocyte (OL) apoptosis in the corpus callosum, accompanied by increased expression of TrkB. This leads to an increased density of doublecortin (DCX)+ neuronal precursor cells and mature NeuN+ neuronal cells in the hippocampus. As a result, BHB treatment effectively promotes the generation of PDGF-Ra+ (oligodendrocyte precursor cells, OPCs), Sox2+ cells and GFAP+ (astrocytes), and decreased the production of GFAP+ TRAP1+ cells, and Oligo2+ TRAP1+ cells in the corpus callosum of mouse brain. Thus, our results demonstrate that BHB treatment efficiently supports OPC differentiation and decreases the OLs apoptosis in CPZ-intoxicated mice, partly by down-regulating the expression of TRPA1 and PARP, which is associated with the inhibition of the p38-MAPK/JNK/JUN pathway and the activation of ERK1/2, PI3K/AKT/mTOR signaling, supporting BHB treatment adjunctive nutritional therapy for the treatment of chronic demyelinating diseases, such as multiple sclerosis (MS).

Myelin repair in Alzheimer's disease: a review of biological pathways and potential therapeutics

This literature review investigates the significant overlap between myelin-repair signaling pathways and pathways known to contribute to hallmark pathologies of Alzheimer's disease (AD). We discuss previously investigated therapeutic targets of amyloid, tau, and ApoE, as well as other potential therapeutic targets that have been empirically shown to contribute to both remyelination and progression of AD. Current evidence shows that there are multiple AD-relevant pathways which overlap significantly with remyelination and myelin repair through the encouragement of oligodendrocyte proliferation, maturation, and myelin production. There is a present need for a single, cohesive model of myelin homeostasis in AD. While determining a causative pathway is beyond the scope of this review, it may be possible to investigate the pathological overlap of myelin repair and AD through therapeutic approaches.

Research progress on the pharmacological effects of matrine

Matrine possesses anti-cancer properties, as well as the prevention and treatment of allergic asthma, and protection against cerebral ischemia-reperfusion injury. Its mechanism of action may be (1) regulation of cancer cell invasion, migration, proliferation, and cell cycle to inhibit tumor growth; (2) reduction of oxidized low-density lipoprotein and advanced glycation end products from the source by exerting anti-inflammatory and antioxidant effects; (3) protection of brain damage and cortical neurons by regulating apoptosis; (4) restoration of the intestinal barrier and regulation of the intestinal microbiota. This article aims to explore matrine’s therapeutic potential by summarizing comprehensive information on matrine’s pharmacology, toxicity, and bioavailability.

Matrine Exerts Pharmacological Effects Through Multiple Signaling Pathways: A Comprehensive Review

As The main effective monomer of the traditional Chinese medicine Sophora flavescens Ait, matrine has a broad scope of pharmacological activities such as anti-tumor, anti-inflammatory, analgesic, anti-fibrotic, anti-viral, anti-arrhythmia, and improving immune function. These actions explain its therapeutic effects in various types of tumors, cardiopathy, encephalomyelitis, allergic asthma, rheumatoid arthritis (RA), osteoporosis, and central nervous system (CNS) inflammation. Evidence has shown that the mechanism responsible for the pharmacological actions of matrine may be via the activation or inhibition of certain key molecules in several cellular signaling pathways including the phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR), transforming growth factor-β/mothers against decapentaplegic homolog (TGF-β/Smad), nuclear factor kappa B (NF-κB), Wnt (wingless/ integration 1)/β-catenin, mitogen-activated protein kinases (MAPKs), and Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathways. This review comprehensively summarizes recent studies on the pharmacological mechanisms of matrine to provide a theoretical basis for molecular targeted therapies and further development and utilization of matrine.

Systematic analysis of chemical profiles of Sophorae tonkinensis Radix et Rhizoma in vitro and in vivo by UPLC-Q-TOF-MSE

Sophorae tonkinensis Radix et Rhizoma (S. tonkinensis) has been recorded as a "poisonous" Chinese herbal medicine in Chinese Pharmacopoeia 2020. The clinical reaction reports of S. tonkinensis indicated its neurotoxicity, there exists still dispute about its toxic substances. At present, there is no report on the blood and brain prototype research of S. tonkinensis. Most studies focused on alkaloids, and less on other compounds. Moreover, the constituents absorbed into the blood and brain were rarely investigated so far. In this study, a rapid and efficient qualitative analysis method was established by UPLC-Q-TOF-MS^E to characterize S. tonkinensis ingredients and those entering into the rat body after oral administration. A total of 91 compounds were identified in S. tonkinensis, of which 28 were confirmed by the standards. 30 and 19 prototypes were also firstly identified in rat blood and brain, respectively. It was found that except for alkaloids, most flavonoids were detected in the rat body and distributed in the cerebrospinal fluid, suggesting that flavonoids may be one of the important toxic or effective substances of S. tonkinensis, which provides new clues and data for clarifying its toxicity or efficacy of the medical plant.

Natural products attenuate PI3K/Akt/mTOR signaling pathway: A promising strategy in regulating neurodegeneration

BACKGROUND

As common, progressive, and chronic causes of disability and death, neurodegenerative diseases (NDDs) significantly threaten human health, while no effective treatment is available. Given the engagement of multiple dysregulated pathways in neurodegeneration, there is an imperative need to target the axis and provide effective/multi-target agents to tackle neurodegeneration. Recent studies have revealed the role of phosphoinositide 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) in some diseases and natural products with therapeutic potentials.

PURPOSE

This is the first systematic and comprehensive review on the role of plant-derived secondary metabolites in managing and/or treating various neuronal disorders via the PI3K/Akt/mTOR signaling pathway.

STUDY DESIGN AND METHODS

A systematic and comprehensive review was done based on the PubMed, Scopus, Web of Science, and Cochrane electronic databases. Two independent investigators followed the PRISMA guidelines and included papers on PI3K/Akt/mTOR and interconnected pathways/mediators targeted by phytochemicals in NDDs.

RESULTS

Natural products are multi-target agents with diverse pharmacological and biological activities and rich sources for discovering and developing novel therapeutic agents. Accordingly, recent studies have shown increasing phytochemicals in combating Alzheimer's disease, aging, Parkinson's disease, brain/spinal cord damages, depression, and other neuronal-associated dysfunctions. Amongst the emerging targets in neurodegeneration, PI3K/Akt/mTOR is of great importance. Therefore, attenuation of these mediators would be a great step towards neuroprotection in such NDDs.

CONCLUSION

The application of plant-derived secondary metabolites in managing and/or treating various neuronal disorders through the PI3K/Akt/mTOR signaling pathway is a promising strategy towards neuroprotection.

Matrine treatment induced an A2 astrocyte phenotype and protected the blood-brain barrier in CNS autoimmunity

Type 1 astrocytes (A1), which are highly proinflammatory and neurotoxic, are prevalent in multiple sclerosis (MS). In addition, in MS and its animal model, experimental autoimmune encephalomyelitis (EAE), immune cells must cross the blood-brain barrier (BBB) and infiltrate into the parenchyma of the central nervous system (CNS) in order to induce neurological deficits. We have previously reported that treatment of EAE with matrine (MAT), a quinazine alkaloid derived from Sophorae Flavescens, effectively inhibited CNS inflammation and promoted neuroregeneration. However, the impact of MAT treatment on astrocyte phenotype is not known. In the present study, we showed that MAT treatment inhibited the generation of neurotoxic A1 astrocytes and promoted neuroprotective A2 astrocytes in the CNS of EAE, most likely by inhibiting production of the A1-inducing cytokine cocktail. MAT also downregulated the expression of vascular endothelial growth factor-A (VEGF-A) and upregulated tight junction proteins Claudin 5 and Occludin, thus protecting the BBB from CNS inflammation-induced damage. Moreover, MAT treatment promotes the formation of astrocyte tight junctions at glia limitans, thereby limiting parenchymal invasion of the CNS by immune cells. Taken together, the inhibition of A1 astrogliogenesis, and the dual effects on the BBB and astrocytic glia limitans, may be the mechanisms whereby MAT significantly improves EAE clinical scores and neuroprotection.

IL-17 Inhibits Oligodendrocyte Progenitor Cell Proliferation and Differentiation by Increasing K+ Channel Kv1.3

Interleukin 17 (IL-17) is a signature cytokine of Th17 cells. IL-17 level is significantly increased in inflammatory conditions of the CNS, including but not limited to post-stroke and multiple sclerosis. IL-17 has been detected direct toxicity on oligodendrocyte (Ol) lineage cells and inhibition on oligodendrocyte progenitor cell (OPC) differentiation, and thus promotes myelin damage. The cellular mechanism of IL-17 in CNS inflammatory diseases remains obscure. Voltage-gated K⁺ (Kv) channel 1.3 is the predominant Kv channel in Ol and potentially involved in Ol function and cell cycle regulation. Kv1.3 of T cells involves in immunomodulation of inflammatory progression, but the role of Ol Kv1.3 in inflammation-related pathogenesis has not been fully investigated. We hypothesized that IL-17 induces myelin injury through Kv1.3 activation. To test the hypothesis, we studied the involvement of OPC/Ol Kv1.3 in IL-17-induced Ol/myelin injury in vitro and in vivo. Kv1.3 currents and channel expression gradually decreased during the OPC development. Application of IL-17 to OPC culture increased Kv1.3 expression, leading to a decrease of AKT activation, inhibition of proliferation and myelin basic protein reduction, which were prevented by a specific Kv1.3 blocker 5-(4-phenoxybutoxy) psoralen. IL-17-caused myelin injury was validated in LPC-induced demyelination mouse model, particularly in corpus callosum, which was also mitigated by aforementioned Kv1.3 antagonist. IL-17 altered Kv1.3 expression and resultant inhibitory effects on OPC proliferation and differentiation may by interrupting AKT phosphorylating activation. Taken together, our results suggested that IL-17 impairs remyelination and promotes myelin damage by Kv1.3-mediated Ol/myelin injury. Thus, blockade of Kv1.3 as a potential therapeutic strategy for inflammatory CNS disease may partially attribute to the direct protection on OPC proliferation and differentiation other than immunomodulation.

Matrine treatment reduces retinal ganglion cell apoptosis in experimental optic neuritis

Inflammatory demyelination and axonal injury of the optic nerve are hallmarks of optic neuritis (ON), which often occurs in multiple sclerosis and is a major cause of visual disturbance in young adults. Although a high dose of corticosteroids can promote visual recovery, it cannot prevent permanent neuronal damage. Novel and effective therapies are thus required. Given the recently defined capacity of matrine (MAT), a quinolizidine alkaloid derived from the herb Radix Sophorae flavescens, in immunomodulation and neuroprotection, we tested in this study the effect of matrine on rats with experimental autoimmune encephalomyelitis, an animal model of multiple sclerosis. MAT administration, started at disease onset, significantly suppressed optic nerve infiltration and demyelination, with reduced numbers of Iba1⁺ macrophages/microglia and CD4⁺ T cells, compared to those from vehicle-treated rats. Increased expression of neurofilaments, an axon marker, reduced numbers of apoptosis in retinal ganglion cells (RGCs). Moreover, MAT treatment promoted Akt phosphorylation and shifted the Bcl-2/Bax ratio back towards an antiapoptotic one, which could be a mechanism for its therapeutic effect in the ON model. Taken as a whole, our results demonstrate that MAT attenuated inflammation, demyelination and axonal loss in the optic nerve, and protected RGCs from inflammation-induced cell death. MAT may therefore have potential as a novel treatment for this disease that may result in blindness.

Ponesimod modulates the Th1/Th17/Treg cell balance and ameliorates disease in experimental autoimmune encephalomyelitis

Sphingosine-1-phosphate receptor 1 (S1P1) plays an important role in autoimmune disease. Here, we evaluated whether ponesimod, an S1P1 modulator, affects inflammation in experimental autoimmune encephalomyelitis (EAE) and investigated Th1/Th2/Th17/Treg cell subsets. Ponesimod treatment ameliorated EAE and alleviated inflammatory infiltration. Compared with untreated EAE, ponesimod-treated mice had lower Th1 and Th17 cell numbers and higher Treg cell numbers; their IFN-γ, T-bet, IL-17, and RORγt levels as well as their pmTOR/mTOR ratio were diminished, while their TGF-β and Foxp3 levels were enhanced. These results suggest that ponesimod modulates the Th1/Th17/Treg balance and regulates the mTOR pathway.

Illumination of Molecular Pathways in Multiple Sclerosis Lesions and the Immune Mechanism of Matrine Treatment in EAE, a Mouse Model of MS

The etiology of multiple sclerosis (MS) is not clear, and the treatment of MS presents a great challenge. This study aimed to investigate the pathogenesis and potential therapeutic targets of MS and to define target genes of matrine, a quinolizidine alkaloid component derived from the root of Sophorae flavescens that effectively suppressed experimental autoimmune encephalomyelitis (EAE), an animal model of MS. To this end, the GSE108000 gene data set in the Gene Expression Omnibus Database, which included 7 chronic active MS lesions and 10 control samples of white matter, was analyzed for differentially expressed genes (DEGs). X cell was used to analyze the microenvironmental differences in brain tissue samples of MS patients, including 64 types of immune cells and stromal cells. The biological functions and enriched signaling pathways of DEGs were analyzed by multiple approaches, including GO, KEGG, GSEA, and GSVA. The results by X cell showed significantly increased numbers of immune cell populations in the MS lesions, with decreased erythrocytes, megakaryocytes, adipocytes, keratinocytes, endothelial cells, Th1 cells and Tregs. In GSE108000, there were 637 DEGs, including 428 up-regulated and 209 down-regulated genes. Potential target genes of matrine were then predicted by the network pharmacology method of Traditional Chinese medicine, and 12 key genes were obtained by cross analysis of the target genes of matrine and DEGs in MS lesions. Finally, we confirmed by RT-PCR the predicted expression of these genes in brain tissues of matrine-treated EAE mice. Among these genes, 2 were significantly downregulated and 6 upregulated by matrine treatment, and the significance of this gene regulation was further investigated. In conclusion, our study defined several possible matrine target genes, which can be further elucidated as mechanism(s) of matrine action, and novel targets in the treatment of MS.

Effects of PI3K/AKT/mTOR pathway regulation of HIF-1α on Lanthanum-induced neurotoxicity in rats

This study examined the effects of the AKT/mTOR/HIF-1α signaling pathway on learning and memory in offspring rats induced by lanthanum from neuroethology and molecular biology perspectives. 32 pregnant adult Wistar rats were divided into four groups randomly: control group (NC), 0.25%, 0.5% and 1.0% LaCl3 groups (n = 8). All rats were poisoned through free drinking from day 0 of pregnancy to postnatal day 21 (suckling period). All offspring rats were poisoned through free drinking from delactation to postnatal day 48. Offspring rats aged 49-days-old were used as sampling objects to construct an LaCl3 poisoning model of offspring rats. Changes in hippocampal neurons, apoptosis of hippocampal neurons, learning and memory abilities of LaCl3-poisoned animals were measured by Nissl staining, TUNEL method and the shuttle box test, respectively. Expressions of PI3K, AKT, and mTOR, HIF-1α, and VEGF in the hippocampus were tested by qPCR and Western blot. Distributions of PI3K and p-AKT in hippocampal neurons were observed through the immunohistochemical method. With increasing LaCl3 dose, lightning strike time and active avoidance incubation period of offspring rats in the different LaCl3 groups were significantly prolonged. The Nissl body positive neurons of hippocampal neurons gradually declined while apoptosis in cells increased. The expressions of both mRNA (PI3K, AKT, mTOR, HIF-1α, VEGF) and proteins (PI3K, p-AKT, p-mTOR, HIF-1α, VEGF) in the hippocampus of the LaCl3 groups were significantly lower than those of NC group (p < 0.05). LaCl3 poisoning can induce developmental injuries in hippocampal neurons and can increase cell apoptosis. As a result, learning and memory abilities of offspring rats, as well as the expressions of PI3K/AKT/mTOR, are decreased, thus inhibiting activation of HIF-1α and influencing the expression of the downstream VEGF gene.

Cuprizone-Induced Demyelination in Mouse Hippocampus Is Alleviated by Ketogenic Diet

Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system (CNS). Recently, ketogenic diet (KD) supplementation has attracted great interest. Therefore, we established the cuprizone (CPZ)-induced demyelination mouse model to investigate the possible neuroprotective effect of KD on the hippocampus of mice. We found that KD significantly elevated the level of serum β-hydroxybutyric acid, improved behavioral and motor abnormalities, and impaired the spatial learning and memory of CPZ-induced demyelination mice. Meanwhile, KD lessened the hippocampal demyelination by enhancing the expression of mature oligodendrocytes (OLs), which was revealed by the elevated expression of MBP and CNPase, as well as the luxol fast blue-staining intensity. Furthermore, KD inhibits the activation of microglia (especially M1-like microglia) and reactive astrocytes. Interestingly, KD attenuated the CPZ-induced oxidative stress by decreasing the malondialdehyde (MDA) content and restoring the glutathione (GSH) levels. In addition, the double immunofluorescence staining revealed that KD enhanced the expression of SIRT1 in astrocytes, microglia, and mature oligodendrocytes. Concomitantly, Western blot demonstrated that KD increased the expression of SIRT1, phosphorylated-AKT, mTOR, and PPAR-γ. In conclusion, KD exerted a neuroprotective effect on CPZ-induced demyelination mice, and this activity was associated with the modulation of the SIRT1/PPAR-γ and SIRT1/P-Akt/mTOR pathways.

A Systematic Review of the Pharmacology, Toxicology and Pharmacokinetics of Matrine

Matrine (MT) is a naturally occurring alkaloid and an bioactive component of Chinese herbs, such as Sophora flavescens and Radix Sophorae tonkinensis. Emerging evidence suggests that MT possesses anti-cancer, anti-inflammatory, anti-oxidant, antiviral, antimicrobial, anti-fibrotic, anti-allergic, antinociceptive, hepatoprotective, cardioprotective, and neuroprotective properties. These pharmacological properties form the foundation for its application in the treatment of various diseases, such as multiple types of cancers, hepatitis, skin diseases, allergic asthma, diabetic cardiomyopathy, pain, Alzheimer's disease (AD), Parkinson's disease (PD), and central nervous system (CNS) inflammation. However, an increasing number of published studies indicate that MT has serious adverse effects, the most obvious being liver toxicity and neurotoxicity, which are major factors limiting its clinical use. Pharmacokinetic studies have shown that MT has low oral bioavailability and short half-life in vivo. This review summarizes the latest advances in research on the pharmacology, toxicology, and pharmacokinetics of MT, with a focus on its biological properties and mechanism of action. The review provides insight into the future of research on traditional Chinese medicine.

Matrine: A Promising Natural Product With Various Pharmacological Activities

Matrine is an alkaloid isolated from the traditional Chinese medicine Sophora flavescens Aiton. At present, a large number of studies have proved that matrine has an anticancer effect can inhibit cancer cell proliferation, arrest cell cycle, induce apoptosis, and inhibit cancer cell metastasis. It also has the effect of reversing anticancer drug resistance and reducing the toxicity of anticancer drugs. In addition, studies have reported that matrine has a therapeutic effect on Alzheimer's syndrome, encephalomyelitis, asthma, myocardial ischemia, rheumatoid arthritis, osteoporosis, and the like, and its mechanism is mainly related to the inhibition of inflammatory response and apoptosis. Its treatable disease spectrum spans multiple systems such as the nervous system, circulatory system, and immune system. The antidisease effect and mechanism of matrine are diverse, so it has high research value. This review summarizes recent studies on the pharmacological mechanism of matrine, with a view to providing reference for subsequent research.

Nonlinear and mixed inhibitory effect of matrine on the cytotoxicity of oligomeric amyloid-β protein

The formation of amyloid β-protein (1-42) (Aβ42) oligomers and Aβ42 oligomer cytotoxicity are two defining characteristics of the etiology of Alzheimer's disease (AD). In this study, we found that matrine (Mat) could maintain or even enhance the cytotrophic effect of Aβ42 monomers by inhibiting their aggregation and by working in a manner similar to synergy with Aβ42 monomers. Moreover, Mat could also exert a cytoprotective effect by actively promoting the disaggregation of immature Aβ42 oligomers in a concentration-dependent manner. Although Mat at intermediate concentrations (1-50 μM) exhibited both cytotrophic and cytoprotective effects on SH-SY5Y cells, Mat at higher concentrations (100 μM) only exhibited a cytoprotective effect. Molecular docking studies reveal that these differences are a result of the different interactions between Mat and Aβ42 oligomers that occur at different molecular ratios. Our results support the hypothesis that there may be a Mat-like metabolite in the human brain that acts as a molecular chaperone for Aβ42 monomers. A deficiency in this chaperone would result in the gradual aggregation of Aβ42 monomers, and eventually, formation of toxic Aβ42 oligomers. In addition, reduction or clearance of Aβ42 aggregates or deposits and inhibition or elimination of the toxicity of oligomeric Aβ42, were not always directly correlated. Finally, the site(s) responsible for cytotoxicity in Aβ42 oligomers may be located in the integrated region of the N-terminal fragments of Aβ42 chains. This study provides valuable insights into the mechanisms involved in the development of natural drugs for the treatment of Alzheimer's disease.

Oligogenesis in the "oligovascular unit" involves PI3K/AKT/mTOR signaling in hypoxic-ischemic neonatal mice

The "oligovascular unit" is a dynamic structural complex composed of endothelial cells (ECs) and oligodendrocyte progenitor cells (OPCs)/oligodendrocytes. By improving the microenvironment of OPCs in the "oligovascular unit" and promoting the proliferation and differentiation of OPCs, both myelination and white matter injury can be repaired. However, it is unclear what characteristic changes occur in the microenvironment of the "oligovascular unit" after preterm white matter injury (PWMI). Here, we demonstrate the changes in the "oligovascular unit" induced by hypoxia-ischemia (HI) and its underlying mechanism in PWMI mice. White matter injury and inhibited production of myelin from OPCs were observed by histopathological staining in HI neonatal mice. We further observed that the proliferation of OPCs and angiogenesis were increased after HI, which is considered the response of the body and cells to HI. HI-induced oligogenesis occurs around the vessels, indicating that "oligovascular units" exist and promote the proliferation and differentiation of OPCs after HI in the short term. We also determined that angiogenesis and oligogenesis induced by HI in the white matter are related to the PI3K/AKT/mTOR pathway. Furthermore, the myelin sheaths were shown to be disordered on the side of the surgery, and the myelin-dense layer was poorly developed at P14 and P28. Different degrees of damage to the vascular ECs and basement membrane on the surgical side were detected beginning at P4, indicating that EC injury is an early phenomenon that subsequently affects oligogenesis. Taken together, our findings indicate that the proliferation of OPCs and angiogenesis in white matter are increased in the early stage of HI involving PI3K/AKT/mTOR pathway activation. Promoting vascular endothelial function and angiogenesis may increase the proliferation and survival of OPCs via the "oligovascular unit," which suggests a potential method to repair injured white matter in the early stage of PWMI.

Matrine alleviates astrogliosis through sphingosine 1-phosphate signaling in experimental autoimmune encephalomyelitis

Expression of sphingosine/sphingosine 1-phosphate (SPH/S1P) in resident cells of the central nervous system plays an important role in the pathogenesis of multiple sclerosis (MS). Accumulated evidence has shown the protective effects of S1P receptor modulators on MS and its animal model, experimental autoimmune encephalomyelitis (EAE). However, effective therapies to regulate SPH/S1P molecules themselves have not been well addressed. Our previous studies showed that matrine (MAT), a natural alkaloid component extracted from the Sophora root, has beneficial effects in EAE through immunomodulation. Here we demonstrate that MAT alleviated astrogliosis in the CNS of EAE rats, and downregulated levels of SPH, S1P and S1P1 expression in CNS tissues and astrocytes. Expression of SPH kinases (SPHK) 1 and 2, which splice SPH into S1P, was also inhibited by MAT treatment. In vitro studies showed a direct inhibitory effect of MAT on S1P1 expression of activated astrocytes, suggesting that MAT could function as an S1PRs antagonist. Moreover, MAT upregulated the expression of plasma gelsolin, which combines with S1P to reduce its concentration. These findings indicate that MAT could alleviate astrogliosis in EAE through diminishing the SPH/SPHK/S1P1 pathway.

A target-group-change couple with mass defect filtering strategy to identify the metabolites of "Dogel ebs" in rats plasma, urine and bile

"Dogel ebs" was known as Sophora flavescens Ait., a classical traditional Chinese Mongolian herbal medicine, which had the effects on damp-heat dysentery, scrofula, and syndrome of accumulated dampness toxicity. Although the chemical constituents have been clarified by our previous studies, the metabolic transformation of "Dogel ebs" in vivo was still unclear. To explore the mechanism of "Dogel ebs," the metabolites in plasma, bile, and urine samples were investigated. A fast positive and negative ion switching technology was used for the simultaneous determination of flavonoids and alkaloids in "Dogel ebs" in a single run. And a target-group-change coupled with mass defect filtering strategy was utilized to analyze the collected data. 89 parent compounds and 82 metabolites were characterized by high-performance liquid chromatography with quadrupole exactive Orbitrap mass spectrometry. Both phase I and phase II metabolites were observed and the metabolic pathways involved in oxidation, demethylation, acetylation, and glucuronidation. 69 metabolites of "Dogel ebs," including three hydroxyls bonding xanthohumol, formononetin-7-O-glucuronide, 2'-hydroxyl-isoxanthohumol decarboxylation metabolite, oxysophocarpine dehydrogen, 9α-hydroxysophoramine-O-glucuronide, etc. were reported for the first time.

Matrine Exerts Antidepressant-Like Effects on Mice: Role of the Hippocampal PI3K/Akt/mTOR Signaling

BACKGROUND

Current antidepressants in clinical use always take weeks or even months to exert full therapeutic effects, and sometimes have serious side effects. Thus, it is very necessary to develop novel antidepressants with better efficacy and fewer adverse effects. The present study focused on investigating the antidepressant potential of matrine and its possible mechanisms of action.

METHODS

The forced swim test, tail suspension test, and chronic unpredictable mild stress model of depression were used to reveal the antidepressant-like effects of matrine on mice. Western blotting, immunohistochemistry, and lentivirus were further used together to explore the antidepressant mechanism of matrine.

RESULTS

It was found that matrine exhibited significant antidepressant actions in the forced swim test and tail suspension test without affecting the locomotor activity of mice. Chronic matrine administration fully reversed the chronic unpredictable mild stress-induced depressive-like symptoms in forced swim test, tail suspension test, and sucrose preference test. After that, western blotting analysis revealed that chronic matrine treatment restored the decreasing effects of chronic unpredictable mild stress on the PI3K/Akt/mammalian target of rapamycin signaling in hippocampus, but not prefrontal cortex. Furthermore, pharmacological and genetic blockade of the PI3K/Akt/mammalian target of rapamycin signaling in hippocampus abolished the antidepressant actions of matrine on mice.

CONCLUSIONS

Taken together, matrine produces antidepressant-like effects on mice via promoting the hippocampal PI3K/Akt/ mammalian target of rapamycin signaling.

Matrine Is Identified as a Novel Macropinocytosis Inducer by a Network Target Approach

Comprehensively understanding pharmacological functions of natural products is a key issue to be addressed for the discovery of new drugs. Unlike some single-target drugs, natural products always exert diverse therapeutic effects through acting on a "network" that consists of multiple targets, making it necessary to develop a systematic approach, e.g., network pharmacology, to reveal pharmacological functions of natural products and infer their mechanisms of action. In this work, to identify the "network target" of a natural product, we perform a functional analysis of matrine, a marketed drug in China extracted from a medical herb Ku-Shen (Radix Sophorae Flavescentis). Here, the network target of matrine was firstly predicted by drugCIPHER, a genome-wide target prediction method. Based on the network target of matrine, we performed a functional gene set enrichment analysis to computationally identify the potential pharmacological functions of matrine, most of which are supported by the literature evidence, including neurotoxicity and neuropharmacological activities of matrine. Furthermore, computational results demonstrated that matrine has the potential for the induction of macropinocytosis and the regulation of ATP metabolism. Our experimental data revealed that the large vesicles induced by matrine are consistent with the typical characteristics of macropinosome. Our verification results also suggested that matrine could decrease cellular ATP level. These findings demonstrated the availability and effectiveness of the network target strategy for identifying the comprehensive pharmacological functions of natural products.