Matrine downregulates IL-33/ST2 expression in the central nervous system of rats with experimental autoimmune encephalomyelitis

IL-33/ST2 Axis: A Potential Therapeutic Target in Neurodegenerative Diseases

Interleukin 33 (IL-33) belongs to the IL-1 family and is localized in the nucleus. IL-33 is primarily composed of three distinct domains, namely the N-terminal domain responsible for nuclear localization, the intermediate sense protease domain, and the C-terminal cytokine domain. Its specific receptor is the suppression of tumorigenicity 2 (ST2), which is detected in serum-stimulated fibroblasts and oncogenes. While most other cytokines are actively produced in cells, IL-33 is passively produced in response to tissue damage or cell necrosis, thereby suggesting its role as an alarm following cell infection, stress, or trauma. IL-33 plays a crucial role in congenital and acquired immunity, which assists in the response to environmental stress and maintains tissue homeostasis. IL-33/ST2 interaction further produces many pro-inflammatory cytokines. Moreover, IL-33 is crucial for central nervous system (CNS) homeostasis and the pathogenic mechanisms underlying CNS degenerative disorders. The present work summarizes the structure of IL-33, its fundamental activities, and its role in immunoregulation and neurodegenerative diseases. Therefore, this work proposes that IL-33 may play a role in the pathogenic mechanism of diseases and can be used in the development of treatment strategies.

Quinolizidine-Type Alkaloids: Chemodiversity, Occurrence, and Bioactivity

Quinolizidine alkaloids (QAs) are nitrogen-containing compounds produced naturally as specialized metabolites distributed in plants and animals (e.g., frogs, sponges). The present review compiles the available information on the chemical diversity and biological activity of QAs reported during the last three decades. So far, 397 QAs have been isolated, gathering 20 different representative classes, including the most common such as matrine (13.6%), lupanine (9.8%), anagyrine (4.0%), sparteine (5.3%), cytisine (6.5%), tetrahydrocytisine (4.3%), lupinine (12.1%), macrocyclic bisquinolizidine (9.3%), biphenylquinolizidine lactone (7.1%), dimeric (7.1%), and other less known QAs (20.9%), which include several structural patterns of QAs. A detailed survey of the reported information about the bioactivities of these compounds indicated their potential as cytotoxic, antiviral, antimicrobial, insecticidal, anti-inflammatory, antimalarial, and antiacetylcholinesterase compounds, involving favorable putative drug-likeness scores. In this regard, research progress on the structural and biological/pharmacological diversity of QAs requires further studies oriented on expanding the chemical space to find bioactive scaffolds based on QAs for pharmacological and agrochemical applications.

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.

Role of IL-33/ST2 Axis in Chronic Inflammatory Neurological Disorderss

Interleukin-33 (IL-33) is a member of IL-1 family of cytokines, produced constitutively by fibroblasts, endothelial cells, and epithelial cells. IL-33 can be released passively from cells during tissue damage and cell necrosis, suggesting that it may act as an alarmin. Function of IL-33 is mediated by its interaction with ST2 molecule that is expressed on many immune cells: Th2 lymphocytes, NK, NKT and mast cells, monocytes, dendritic cells and granulocytes. IL-33/ST2 pathway plays, often dual, roles in different physiological and inflammatory processes, mediating both, pathological immune responses and tissue repair. Expression of IL-33 in the central nervous system (CNS) is significantly enhanced during various pathological processes, indicating its important role in the pathogenesis of neurological inflammatory and degenerative diseases. In this review the biological features, expression of IL-33 and its ligand ST2 in CNS, and the role of IL- 33/ST2 pathway in development of Alzheimer’s disease and multiple sclerosis are discussed.

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.

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.

Autophagy inhibition enhances Matrine derivative MASM induced apoptosis in cancer cells via a mechanism involving reactive oxygen species-mediated PI3K/Akt/mTOR and Erk/p38 signaling

Background

In the quest for new anti-cancer drugs, the drug discovery process has shifted to screening of active ingredients in traditional eastern medicine. Matrine is an active alkaloid isolated from plants of the Sophora genus used in traditional Chinese herbal medicine that exhibits a wide spectrum of biological properties and has a potential as an anti-proliferative agent. In this study, we investigated the anticancer property of MASM, ([(6aS, 10S, 11aR, 11bR, 11cS)210-Methylamino-dodecahydro-3a, 7a-diaza-benzo (de)anthracene-8-thione]), a potent derivative of matrine.

Methods

Four epithelial cancer cell lines representing the dominant cancers, namely: A549 (non-small-cell lung cancer cell line), MCF-7 and MDA-MB-231 (breast cancer cell lines), and Hela (cervical cancer cell line) were employed, and the mechanistic underpinning of MASM-induced apoptosis was investigated using flow cytometry, western blot and immunofluorescence.

Results

MASM, induced apoptosis via caspase 3 dependent and independent pathways, and autophagy in all the four cancer cell lines, but post-EMT (epithelial mesenchymal transition) cells showed greater sensitivity to MASM. Scavenging reactive oxygen species using N-acetylcysteine rescued all cancer cell lines from apoptosis and autophagy. Mechanistic analysis revealed that MASM induced autophagy involves inhibition of Akt signaling and the activation of Erk and p38 signaling, and inhibition of autophagy further enhanced the apoptosis induced by MASM.

Conclusions

These results indicate that MASM possesses potency against cancer cells and modulating autophagy during MASM administration could be used to further enhance its therapeutic effects.

Natural products as a potential modulator of microglial polarization in neurodegenerative diseases

Neurodegenerative diseases (NDs) are characterized by the progressive loss of structure and function of neurons most common in elderly population, mainly including Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS) and multiple sclerosis (MS). Neuroinflammation caused by microglia as the resident macrophages of the central nervous system (CNS) plays a contributory role in the onset and progression of NDs. Activated microglia, as in macrophages, to be heterogeneous, can polarize into M1 (pro-inflammatory) and M2 (anti-inflammatory) functional phenotypes. The former elaborate pro-inflammatory mediators promoting neuroinflammation and neuronal damage. In contrast, the latter generate anti-inflammatory mediators and neurotrophins that inhibit neuroinflammation and promote neuronal healing. Consistently, the regulation of microglial polarization from M1 to M2 phenotype appears as an outstanding therapeutic and preventive approach for NDs treatment. Although non-steroidal anti-inflammatory drugs (NSAIDs) currently used to alleviate M1 microglia-associated neuroinflammation responsible for the development of NDs, these drugs have different degrees of adverse effects and limited efficacy. As the advantages of novel structure, multi-target, high efficiency and low toxicity, natural products as the modulators of microglial polarization have attracted considerable concerns in the therapeutic areas of NDs. In this review, we mainly summarized the therapeutic potential of natural products and their various molecular mechanisms for NDs treatment through modulating microglial polarization. The aim of the current review is expected to be useful to develop innovative modulators of microglial polarization from natural products for the amelioration and treatment of NDs.

Expression and Function of IL-33/ST2 Axis in the Central Nervous System Under Normal and Diseased Conditions

Interleukin-33 (IL-33) is a well-recognized immunomodulatory cytokine which plays critical roles in tissue function and immune-mediated diseases. The abundant expression of IL-33 in brain and spinal cord prompted many scientists to explore its unique role in the central nervous system (CNS) under physiological and pathological conditions. Indeed emerging evidence from over a decade's research suggests that IL-33 acts as one of the key molecular signaling cues coordinating the network between the immune and CNS systems, particularly during the development of neurological diseases. Here, we highlight the recent advances in our knowledge regarding the distribution and cellular localization of IL-33 and its receptor ST2 in specific CNS regions, and more importantly the key roles IL-33/ST2 signaling pathway play in CNS function under normal and diseased conditions.