Ligustrazine Attenuates Hyperhomocysteinemia-induced Alzheimer-like Pathologies in Rats

Herbal medicines in Alzheimer's disease and the involvement of gut microbiota

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by memory loss and cognitive impairment. It severely affects the quality of life of victims. The prevalence of AD has been increasing in recent years. Therefore, it is of great importance to elucidate the pathogenic mechanism of AD and search for effective therapeutic approaches. Gut microbiota dysbiosis, an altered state of gut microbiota, has been well known for its involvement in the pathogenesis of AD. Much effort has been made in searching for approaches capable of modulating the composition of gut microbiota in recent years. Herbal medicines have attracted extensive attention in recent decades for the prevention and treatment of AD. Here, we gave an overview of the recent research progress on the modulatory effects of herbal medicines and herbal formulae on gut microbiota as well as the possible beneficial effects on AD, which may provide new insights into the discovery of anti-AD agents and their therapeutic potential for AD through modulating the composition of gut microbiota.

Bitter yet beneficial: The dual role of dietary alkaloids in managing diabetes and enhancing cognitive function

With the rising prevalence of diabetes and its association with cognitive impairment, interest in the use of dietary alkaloids and other natural products has grown significantly. Understanding how these compounds manage diabetic cognitive dysfunction (DCD) is crucial. This comprehensive review explores the etiology of DCD and the effects of alkaloids in foods and dietary supplements that have been investigated as DCD therapies. Data on how dietary alkaloids like berberine, trigonelline, caffeine, capsaicin, 1-deoxynojirimycin, nuciferine, neferine, aegeline, tetramethylpyrazine, piperine, and others regulate cognition in diabetic disorders were collected from PubMed, Research Gate, Web of Science, Science Direct, and other relevant databases. Dietary alkaloids could improve memory in behavioral models and modulate the mechanisms underlying the cognitive benefits of these compounds, including their effects on glucose metabolism, gut microbiota, vasculopathy, neuroinflammation, and oxidative stress. Evidence suggests that dietary alkaloids hold promise for improving cognition in diabetic patients and could open exciting avenues for future research in diabetes management.

Neuroprotection by tetramethylpyrazine and its synthesized analogues for central nervous system diseases: a review

BACKGROUND

Due to the global increase in aging populations and changes in modern lifestyles, the prevalence of neurodegenerative diseases, cerebrovascular disorders, neuropsychiatrcic conditions, and related ailments is rising, placing an increasing burden on the global public health system.

MATERIALS AND METHODS

All studies on tetramethylpyrazine (TMP) and its derivatives were obtained from reputable sources such as PubMed, Elsevier, Library Genesis, and Google Scholar. Comprehensive data on TMP and its derivatives was meticulously compiled.

RESULTS

This comprehensive analysis explains the neuroprotective effects demonstrated by TMP and its derivatives in diseases of the central nervous system. These compounds exert their influence on various targets and signaling pathways, playing crucial roles in the development of various central nervous system diseases. Their multifaceted mechanisms include inhibiting oxidative damage, inflammation, cell apoptosis, calcium overload, glutamate excitotoxicity, and acetylcholinesterase activity.

CONCLUSION

This review provides a brief summary of the most recent advancements in research on TMP and its derivatives in the context of central nervous system diseases. It involves synthesizing analogs of TMP and evaluating their effectiveness in models of central nervous system diseases. The ultimate goal is to facilitate the practical application of TMP and its derivatives in the future treatment of central nervous system diseases.

A New Paradigm in Spinal Cord Injury Therapy: from Cell-free Treatment to Engineering Modifications

Spinal cord injury (SCI) is an intractable and poorly prognostic neurological disease, and current treatments are still unable to cure it completely and avoid sequelae. Extracellular vesicles (EVs), as important carriers of intercellular communication and pharmacological effects, are considered to be the most promising candidates for SCI therapy because of their low toxicity and immunogenicity, their ability to encapsulate endogenous bioactive molecules (e.g., proteins, lipids, and nucleic acids), and their ability to cross the blood-brain/cerebrospinal barriers. However, poor targeting, low retention rate, and limited therapeutic efficacy of natural EVs have bottlenecked EVs-based SCI therapy. A new paradigm for SCI treatment will be provided by engineering modified EVs. Furthermore, our limited understanding of the role of EVs in SCI pathology hinders the rational design of novel EVbased therapeutic approaches. In this study, we review the pathophysiology after SCI, especially the multicellular EVs-mediated crosstalk; briefly describe the shift from cellular to cell-free therapies for SCI treatment; discuss and analyze the issues related to the route and dose of EVs administration; summarize and present the common strategies for EVs drug loading in the treatment of SCI and point out the shortcomings of these drug loading methods; finally, we analyze and highlight the feasibility and advantages of bio-scaffold-encapsulated EVs for SCI treatment, providing scalable insights into cell-free therapy for SCI.

Development of novel celastrol-ligustrazine hybrids as potent peroxiredoxin 1 inhibitors against lung cancer

The disruption of oxidation-reduction equilibrium through inhibiting reactive oxygen species (ROS) clearance or enhancing ROS production has emerged as a novel and promising strategy for cancer therapy. Herein, a series of celastrol-ligustrazine hybrids were designed and synthesized as effective ROS promoters, and their biological activities were further evaluated. Among them, compound 7e stood out as the most potent peroxiredoxin 1 (PRDX1) inhibitor (IC50 = 0.164 μM), which was significant super to the recognized PRDX1 inhibitor Conoidin A (IC50 = 14.80 μM) and the control compound celastrol (IC50 = 1.622 μM). Furthermore, 7e dramatically promoted intracellular ROS accumulation, and inhibited the proliferation, invasion and migration of cancer cells besides inducing apoptosis in vitro. Additionally, 7e suppressed the key signaling pathways (AKT and ERK) and promoted the expression of apoptosis-related proteins (cleaved caspase-3/8 and cleaved PARP) in A549 cells, which resulted in the prevention of tumor progression. Most importantly, compound 7e (TGI = 77.47%) showed more considerable in vivo antitumor efficacy and less toxicity than celastrol (TGI = 71.00%). Overall, this work indicates 7e as the most potential PRDX1 inhibitor and may be a promising candidate for the therapy of lung cancer.

Relationship between the therapeutic potential of various plant-derived bioactive compounds and their related microRNAs in neurological disorders

BACKGROUND

Neurological disorders, such as ischemic stroke, spinal cord injury, neurodegenerative diseases, and glioblastoma often lead to long-term disability and death. MicroRNAs (miRNAs) are small single-stranded non-coding RNAs of approximately 22 nucleotides, known to participate in both normal and pathological development, making them ideal therapeutic targets for clinical intervention. Several recent studies have suggested that plant-derived bioactive compounds (PDBCs) can have anti-atherosclerosis, antioxidant, and anti-inflammatory effects by regulating miRNAs. Thus, miRNAs are novel targets for the action of PDBCs.

PURPOSE

The aim of this review was to evaluate the current status of PDBCs targeted miRNAs by dissecting their development status through a literature review.

METHODS

A manual and electronic search was performed for English articles available from inception up to June 2022 reporting PDBCs and their regulating relationship with miRNAs for the therapeutic potential of neurological disorders. Information was retrieved from scientific databases including PubMed, ScienceDirect, Web of Science, Google Scholar and Chemical Abstracts Services. Keywords used for the search engines were "miRNAs" AND "Plant-derived bioactive compounds" in conjunction with "(native weeds OR alien invasive)" AND "traditional herbal medicine".

RESULTS

A total of 37 articles were retrieved on PDBCs and their related miRNAs in neurological disorders. These PDBCs from traditional herbal medicine may play a therapeutic role in neurological disorders in a variety of mechanisms by regulating the corresponding miRNAs. These mechanisms mainly include inhibiting oxidative stress, anti-neuroinflammation, anti-autophagy, and anti-apoptosis. PDBC are a group of chemically distinct compounds derived from medicinal plants, some of which have therapeutic effects on neurological disorders.

CONCLUSION

The emergence of miRNAs as pathological regulatory factors provides a new direction for the study of bioactive compounds in Traditional Chinese medicine and the elucidating of their epigenetic effects. Elucidating the regulatory relationship between bioactive compounds and miRNAs may help to identify new therapeutic targets and promoting the application of these compounds in precision medicine through their targeted molecular activity.

Research progress in traditional Chinese medicine in the treatment of Alzheimer's disease and related dementias

Alzheimer's disease (AD) is the world's leading cause of dementia and has become a huge economic burden on nations and families. However, the exact etiology of AD is still unknown, and there are no efficient medicines or methods to prevent the deterioration of cognition. Traditional Chinese medicine (TCM) has made important contributions in the battle against AD based on the characteristics of multiple targets of TCM. This study reviewed the treatment strategies and new discoveries of traditional Chinese medicine in current research, which may be beneficial to new drug researchers.

Ligustrazine exerts neuroprotective effects via circ_0008146/miR-709/Cx3cr1 axis to inhibit cell apoptosis and inflammation after cerebral ischemia/reperfusion injury

BACKGROUND

Ligustrazine is a traditional Chinese herbal medicine that has long been used to treat cerebral ischemic disorders. However, the molecular mechanisms of ligustrazine in cerebral ischemia/reperfusion (I/R) damage have not been clear elucidated. The aim of this study was to examine the neuroprotective mechanisms of ligustrazine in cerebral I/R.

METHODS

9 C57BL/6 mice were randomly divided to three groups: Sham group (n = 3), Middle cerebral artery occlusion (MCAO) group (n = 3), and MCAO + Ligustrazine group (n = 3). The neurological deficit score was evaluated, the cerebral infarct volume was measured by triphenylterazolium chloride (TTC) staining. Differentially expressed (DE) messenger RNAs (mRNAs), long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs) were analyzed using the R package DEseq2 based on P-value < 0.05 and Log2 |fold change (FC)| ≥ 2 in sham group vs MCAO group and MCAO group vs ligustrazine group by high-throughput sequencing. Function enrichment analysis, the protein-protein interaction (PPI) of neurogenesis related genes were performed. The neurogenesis related competitive endogenous RNA (ceRNA) network was constructed.

RESULTS

The expression of circ_0008146 was considerably higher in the MCAO group than the Sham group, and ligustrazine treatment markedly decreased the expression of circ_0008146 in MCAO. Next, the circ_0008146 ceRNA network was established, including circ_0008146-miR-709-Cx3cr1 ceRNA network. Besides, real time quantitative polymerase chain reaction (RT-qPCR) assay identified that miR-709 expression was considerably lower and Cx3cr1 expression was higher in the MCAO group than Sham group, and ligustrazine treatment markedly increased the miR-709 expression and reduced Cx3cr1 expression in MCAO. Further, silencing of circ_0008146 inhibited the concentration of Interleukin 6 (IL-6), Tumor Necrosis Factor alpha (TNF-α) and reduced neuron cell death and up-regulated miR-709 expression and down-regulated Cx3cr1 expression in Lipopolysaccharide (LPS) induced BV-2 cells. Dual-Luciferase reporter gene assay verified that circ_0008146 targeted miR-709.

CONCLUSION

Ligustrazine targets circ_0008146/miR-709/Cx3cr1 axis to inhibit cell apoptosis and inflammation after cerebral ischemia/reperfusion injury.

Regulatory mechanisms of tetramethylpyrazine on central nervous system diseases: A review

Central nervous system (CNS) diseases can lead to motor, sensory, speech, cognitive dysfunction, and sometimes even death. These diseases are recognized to cause a substantial socio-economic impact on a global scale. Tetramethylpyrazine (TMP) is one of the main active ingredients extracted from the Chinese herbal medicine Ligusticum striatum DC. (Chuan Xiong). Many in vivo and in vitro studies have demonstrated that TMP has a certain role in the treatment of CNS diseases through inhibiting calcium ion overload and glutamate excitotoxicity, anti-oxidative/nitrification stress, mitigating inflammatory response, anti-apoptosis, protecting the integrity of the blood-brain barrier (BBB) and facilitating synaptic plasticity. In this review, we summarize the roles and mechanisms of action of TMP on ischemic cerebrovascular disease, spinal cord injury, Parkinson’s disease, Alzheimer’s disease, cognitive impairments, migraine, and depression. Our review will provide new insights into the clinical applications of TMP and the development of novel therapeutics.

An Overview of Tetramethylpyrazine (Ligustrazine) and its Derivatives as Potent Anti-Alzheimer’s Disease Agents

Abstract:

Tetramethylpyrazine (TMP), or ligustrazine, is an alkaloid isolated from the Chinese herb Ligusticum wallichii. It is known for its broad-spectrum medicinal properties against several diseases, and various studies have shown that it can modulate diverse biological targets and signaling pathways to produce neuroprotective effects, especially against Alzheimer’s disease (AD). This has attracted significant research attention evaluating TMP as a potent multitarget anti-AD agent. This review compiles the results of studies assessing the neuroprotective mechanisms exerted by TMP as well as its derivatives prepared using a multi-target-directed ligand strategy to explore its multitarget modulating properties. The present review also highlights the work done on the design, synthesis, structure-activity relationships, and mechanisms of some potent TMP derivatives that have shown promising anti-AD activities. These derivatives were designed, synthesized, and evaluated to develop anti-AD molecules with enhanced biological and pharmacokinetic activities compared to TMP. This review article paves the way for the exploration and development of TMP and TMP derivatives as an effective treatment for AD.

A Review of Traditional Chinese Medicine, Buyang Huanwu Decoction for the Treatment of Cerebral Small Vessel Disease

Cerebral small vessel disease (CSVD) is often referred to as “collaterals disease” in traditional Chinese medicine (TCM), and commonly includes ischemic and hemorrhagic CSVD. TCM has a long history of treating CSVD and has demonstrated unique efficacy. Buyang Huanwu Decoction (BHD) is a classical TCM formula that has been used for the prevention and treatment of stroke for hundreds of years. BHD exerts its therapeutic effects on CSVD through a variety of mechanisms. In this review, the clinical and animal studies on BHD and CSVD were systematically introduced. In addition, the pharmacological mechanisms, active components, and clinical applications of BHD in the treatment of CSVD were reviewed. We believe that an in-depth understanding of BHD, its pharmacological mechanism, disease-drug interaction, and other aspects will help in laying the foundation for its development as a new therapeutic strategy for the treatment of CSVD.

Tetramethylpyrazine: A review on its mechanisms and functions

Ligusticum chuanxiong Hort (known as Chuanxiong in China, CX) is one of the most widely used and long-standing medicinal herbs in China. Tetramethylpyrazine (TMP) is an alkaloid and one of the active components of CX. Over the past few decades, TMP has been proven to possess several pharmacological properties. It has been used to treat a variety of diseases with excellent therapeutic effects. Here, the pharmacological characteristics and molecular mechanism of TMP in recent years are reviewed, with an emphasis on the signal-regulation mechanism of TMP. This review shows that TMP has many physiological functions, including anti-oxidant, anti-inflammatory, and anti-apoptosis properties; autophagy regulation; vasodilation; angiogenesis regulation; mitochondrial damage suppression; endothelial protection; reduction of proliferation and migration of vascular smooth muscle cells; and neuroprotection. At present, TMP is used in treating cardiovascular, nervous, and digestive system conditions, cancer, and other conditions and has achieved good curative effects. The therapeutic mechanism of TMP involves multiple targets, multiple pathways, and bidirectional regulation. TMP is, thus, a promising drug with great research potential.

The role of plant-based products in the prevention of neurological complications

BACKGROUND

Neurological complications are most likely to be fatal and cause loss of ability to function or care for self. These include Alzheimer's disease and cognitive impairment. The main aim of the review is to determine the effects of various drugs and their cognitive risk with the need to opt for herbal therapy as an adjuvant in treating neurological conditions like Alzheimer's disease with lesser-known side effects. The Methodology: Involved a detailed literature survey which was performed through an online database, such as Science Direct, Google Scholar, Scopus, Cochrane, and PubMed. The study included randomized trials and original research conducted by herbal supplements on animal models to assess expression of upregulation of signalling pathways. Various studies involved in treating dementia, neurological disorders, Alzheimer disease, cognitive dysfunction were included.

RESULTS

Found that various studies involved plant-based products were showing improvement in prevention of disease and signalling pathways with lesser-known side effects.

CONCLUSION

It was observed that plant-based products play a major role in the prevention of neurological complications. Herbal medicines could most suitably prevent Alzheimer's risk with less known side effects in contrast with the existing treatment patterns. However, to improve the utility of herbal medicines, more evidences from in vitro, in vivo, and clinical trials need to be addressed.