Protective effect and underlying mechanism of muscone on acute cerebral ischemia-reperfusion injury in rats

Ethanol extract of Moschus attenuates glutamate-induced cytotoxicity in HT22 cells by regulating the Nrf2 and MAPK pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Moschus is a traditional Chinese materia medica for treating central nervous system disorders. Oxidative stress is a key pathogenic mechanism of Alzheimer's disease (AD) and serves as a critical bridge linking various pathological processes of AD. Previous studies have shown that Moschus can exert neuroprotective effects by inhibiting glutamate-induced neuronal cell damage. However, its underlying mechanisms remain unclear.

AIM OF THE STUDY

This study aimed to evaluate the effects and potential mechanisms of the ethanol extract of Moschus (EEM) on glutamate-induced oxidative damage in HT22 cells.

MATERIALS AND METHODS

The components of EEM were identified using GC-MS. An oxidative toxicity cell model was established by exposing HT22 cells to glutamate. Cell viability was assessed through CCK8 and LDH assays, and the modes of cell death were evaluated using FITC-Annexin V staining and TUNEL assays. Intracellular and mitochondrial ROS levels were measured with DCFH-DA and MitoSOX Red probes. Intracellular Ca2+ levels were measured with the Fluo-4 AM fluorescent probe. Mitochondrial function was analyzed using the JC-1 fluorescent probe. Protein expression levels of Bid, Calpain-1, Bax, Bcl-2, AIF, P-ERK, ERK, P-JNK, JNK, P-P38, P38, Nrf2, HO-1, Keap1, and NQO-1 were analyzed through western blotting. The distribution of AIF and Nrf2 in the cytoplasm and nucleus was examined through immunofluorescence staining.

RESULTS

Using GC-MS, 18 major components were identified in EEM. EEM significantly inhibited apoptosis, reduced ROS generation, and alleviated Ca2+ overload. EEM restored mitochondrial dysfunction by regulating the expression of mitochondria-related apoptotic proteins, including the downregulation of Calpain-1 and Bax, upregulation of Bid and Bcl-2, and inhibition of AIF nuclear translocation. EEM inhibited MAPK phosphorylation while activating the Nrf2/Keap1 signaling pathway.

CONCLUSIONS

Our study shows that EEM protects HT22 cells from glutamate-induced damage by regulating the MAPK and Nrf2 pathways, effectively reducing oxidative stress and apoptosis. In summary, this study first demonstrates at the cellular level that EEM exerts neuroprotective effects by modulating the MAPK and Nrf2 pathways. These findings provide new insights into the mechanism of Moschus against AD and establish a foundation for its potential application in AD.

Preparation and Characterization of Muscone Oil-Based Cyclodextrin Metal-Organic Frameworks: Molecular Dynamics Simulations and Stability Evaluation

Objective: Muscone (MUS), a primary active component of musk, is known for its significant pharmacological properties. However, its clinical application is limited due to poor water solubility and moderate stability. This study aims to address these limitations by encapsulating MUS within biodegradable γ-cyclodextrin metal-organic frameworks (γ-CD-MOFs) using a solvent-free method to enable oral MUS delivery by improving solubility and stability, pending in vivo validation. Methods: MUS was encapsulated into γ-CD-MOFs using a solvent-free method, achieving an optimal loading rate of 10.6 ± 0.7%. Comprehensive characterization was performed using scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). Biocompatibility was assessed using RAW264.7 cells, and molecular dynamics simulations were conducted to study the interactions between MUS and γ-CD-MOFs. Results: Characterization techniques confirmed the successful encapsulation of MUS into γ-CD-MOFs. Biocompatibility studies revealed no cytotoxicity, indicating that the system is safe for drug delivery. Molecular dynamics simulations showed that MUS preferentially occupies the large spherical cages of γ-CD-MOFs, driven by non-covalent interactions. Solubility tests and in vitro release studies demonstrated that the solubility of MUS was improved after encapsulation within γ-CD-MOFs. Stability assessments indicated that γ-CD-MOFs significantly enhanced the thermal and photostability of MUS, with high residual amounts remaining under various storage conditions. Conclusions: This study demonstrates the potential of γ-CD-MOFs to solidify MUS, enhance its solubility, and improve its storage stability, providing a foundation for its future use in pharmaceutical applications.

Volatile Compounds in Musk and Their Anti-Stroke Mechanisms

Background/Objectives: Musk is a widely used traditional Chinese medicine derived from musk deer that has the pharmacological effects of "activating blood dredging collateral" and "consciousness-restoring resuscitation". Its volatile compounds (VCs) play a key role in these effects, especially in the treatment of stroke. However, there have been no comprehensive studies on the differences in the VCs of these different musks. This study investigated the differences in the VCs of different musks and the potential targets and mechanisms of action for stroke. Methods: Different musks were studied via GC-MS, and the potential targets and mechanisms of VCs associated with stroke were investigated using network pharmacology. Results: A total of 99 VCs were detected in 79 musk samples. The most important VCs of different colours and forms were muscone, phenol, acetic acid, and isovaleric acid. Further study revealed that the change in organic acids and ketones was the cause of the significant difference between white musk and other types of musk. In addition, network pharmacological analyses identified 180 potential targets of the major volatile compounds of musk associated with stroke, and five key targets (SRC, EGFR, ESR1, PTGS2, and DRD2). Enrichment analysis showed that these key targets play an important role in neural related pathways. The molecular docking results confirmed that the key targets can effectively bind with the main VCs (muscone and phenol). Conclusions: These findings provide valuable insights into the distinct volatile compositions of various types of musk and underscore the significant potential of volatile compounds (VCs) in stroke treatment.

Research progress of traditional Chinese medicine in the treatment of ischemic stroke by regulating mitochondrial dysfunction

Ischemic stroke (IS) is a severe cerebrovascular disease with increasing incidence and mortality rates in recent years. The pathogenesis of IS is highly complex, with mitochondrial dysfunction playing a critical role in its onset and progression. Thus, preserving mitochondrial function is a pivotal aspect of treating ischemic brain injury. In response, there has been growing interest among scholars in the regulation of mitochondrial function through traditional Chinese medicine (TCM), including herb-derived compounds, individual herbs, and herbal prescriptions. This article reviews recent research on the mechanisms of mitochondrial dysfunction in IS and explores the potential of TCM in treating this condition by targeting mitochondrial dysfunction.

Impact of SDF-1 and AMD3100 on Hair Follicle Dynamics in a Chronic Stress Model

Chronic stress is a common cause of hair loss, involving inflammatory responses and changes in cellular signaling pathways. This study explores the mechanism of action of the SDF-1/CXCR4 signaling axis in chronic stress-induced hair loss. The research indicates that SDF-1 promotes hair follicle growth through the PI3K/Akt and JAK/STAT signaling pathways. Transcriptome sequencing analysis was conducted to identify differentially expressed genes in the skin of normal and stressed mice, with key genes SDF-1/CXCR4 selected through machine learning and a protein-protein interaction network established. A chronic stress mouse model was created, with injections of SDF-1 and AMD3100 administered to observe hair growth, weight changes, and behavioral alterations and validate hair follicle activity. Skin SDF-1 concentrations were measured, differentially expressed genes were screened, and pathways were enriched. Activation of the PI3K/Akt and JAK/STAT signaling pathways was assessed, and siRNA technology was used in vitro to inhibit the expression of SDF-1 or CXCR4. SDF-1 promoted hair follicle activity, with the combined injection of SDF-1 and AMD3100 weakening this effect. The activation of the PI3K/Akt and JAK/STAT signaling pathways was observed in the SDF-1 injection group, confirmed by Western blot and immunofluorescence. Silencing SDF-1 through siRNA-mediated inhibition reduced cell proliferation and migration abilities. SDF-1 promotes hair growth in chronic stress mice by activating the PI3K/Akt and JAK/STAT pathways, an effect reversible by AMD3100. The SDF-1/CXCR4 axis may serve as a potential therapeutic target for stress-induced hair loss.

Neuroprotective effects of the salidroside derivative SHPL-49 via the BDNF/TrkB/Gap43 pathway in rats with cerebral ischemia

Ischemic stroke is a common intravascular disease and one of the leading causes of death and disability. The salidroside derivative SHPL-49, which we previously synthesized, significantly attenuates cerebral ischemic injury in a rat model of permanent middle cerebral artery occlusion. To explore the neuroprotective mechanism of SHPL-49, the effects of SHPL-49 on the expression levels of neurotrophic factors in neurons and microglia and the polarization of microglia were investigated in the present study. SHPL-49 activated the brain-derived neurotrophic factor (BDNF) pathway, decreased the number of degenerated neurons, and accelerated neurogenesis in rats with cerebral ischemia. In addition, SHPL-49 promoted the polarization of microglia toward the M2 phenotype to alleviate neuroinflammation. In BV2 cells, SHPL-49 upregulated CD206 mRNA and protein levels and inhibited CD86 mRNA and protein levels. SHPL-49 also increased neurotrophic factor secretion in BV2 cells, which indirectly promoted the survival of primary neurons after oxygen-glucose deprivation (OGD). Proteomics analysis revealed that SHPL-49 promoted growth-associated protein 43 (Gap43) expression. SHPL-49 enhanced synaptic plasticity and increased Gap43 protein levels via activation of the BDNF pathway in the OGD primary neuron model. These results indicate that SHPL-49 prevents cerebral ischemic injury by activating neurotrophic factor pathways and altering microglial polarization. Thus, SHPL-49 is a potential neuroprotective agent.

Muscone alleviates neuronal injury via increasing stress granules formation and reducing apoptosis in acute ischemic stroke

As the main bioactive component of musk, muscone has been reported to have marked protective effects in treating acute ischemic stroke (AIS). However, the specific anti-stroke mechanism of muscone still needs further research. In the current investigation, the PC12 cells OGD/R and the rat transient MCAO/R models were utilized as the AIS models. Serum hepatic and renal functional indexes (ALT, AST, BUN, and Cr) and cell viability were determined to select the appropriate muscone concentrations for in vitro and in vivo experiments. TTC, Hematoxylin and eosin (H&E), and Live/Dead staining were utilized to evaluate the protective effects of muscone in injured tissues and cells. Western blotting analysis, TUNEL staining, propidium iodide, and annexin V staining were applied to detect the anti-apoptotic effect of muscone. Double-label immunofluorescence staining of T-cell intracellular antigen-1 (TIA1) and Ras-GAP SH3 domain-binding protein 1 (G3BP1) was performed to observe whether muscone regulated the SG formation level. Molecular docking, TIA1 silencing and TIA1 overexpression experiments were employed to investigate the molecular mechanism underlying the regulation of SG formation by muscone. The 2, 3, 5-Triphenyl-tetrazolium chloride (TTC) staining and live/dead staining showed the AIS injury level of MCAO/R rat and the OGD/R PC12 cells were attenuated by muscone administration. The muscone significantly minimized the apoptosis rate in MCAO/R rats and OGD/R PC12 cells following flow cytometry analysis, western blotting analysis, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. The double-label immunofluorescence staining data revealed that muscone promoted the SG formation level in OGD/R PC12 cells and the cortex MCAO/R rats. The results of molecular docking, TIA1 silencing and TIA1 overexpression experiments revealed that muscone could bind to TIA1 protein and regulate its expression level, thereby promoting the formation of stress granules and exerting a protective effect against AIS injury. This study indicated that the significant protective effect of muscone in reducing apoptosis levels might be via promoting SG formation under AIS conditions. This study further explores the therapeutic effect and anti-apoptosis mechanism of muscone in AIS, which may provide a potential candidate drug for the clinical treatment of AIS injury.

Neuroprotective effects of exosomes derived from bone marrow mesenchymal stem cells treated by Musk Ketone on ischemic stroke

OBJECTIVES

Ischemic stroke (IS) is a leading cause of morbidity and mortality globally. This study aimed to investigate the role of exosomes (Exo) derived from bone marrow mesenchymal stem cells (BMSCs) treated with Musk Ketone (Mus treated-Exo) in the development of IS injury.

METHODS

BMSCs were pretreated with 10 μM Mus for 36 h, and Exo derived from these Mus-treated BMSCs (Mus-treated Exo) were extracted. Rats with middle cerebral artery occlusion (MCAO) were administered either 2 mg/kg of control Exo (Ctrl-Exo), 2 mg/kg of Mus treated-Exo, or 10 μM Mus. Neurological deficit and cerebral infarction in the MCAO rats were assessed utilizing neurological scores and TTC staining. Neuronal apoptosis, activation of microglia/macrophages, and inflammation were evaluated through TUNEL staining, immunofluorescence staining, and western blot analysis, respectively.

RESULTS

Our findings revealed that Mus-treated Exo possessed a more pronounced neuroprotective effect on MCAO rats when compared to Ctrl-Exo and Mus treatment alone. Specifically, Mus treated-Exo effectively ameliorated neurological function, reduced the volume of cerebral infarction, and diminished hemispheric swelling in MCAO rats. Moreover, it inhibited neuronal apoptosis and activation of microglia/macrophages, promoted the expression of the anti-apoptotic protein Bcl-2 while decreasing the expression of pro-apoptotic protein Bax, Cleaved-caspase 3, and pro-inflammatory factors IL-6 and COX-2.

CONCLUSIONS

The findings imply that Mus treated-Exo could confer neuroprotection in rats affected by IS, potentially by attenuating apoptosis and neuroinflammation. The underlying mechanisms, however, warrant further investigation. Mus treated-Exo shows potential as a new therapeutic strategy for IS.

Protective effect of Xinmai'an tablets via mediation of the AMPK/SIRT1/PGC-1α signaling pathway on myocardial ischemia-reperfusion injury in rats

BACKGROUND

Xinmai'an tablets are a compound Chinese medicine comprising six traditional Chinese medicines that have been clinically applied to treat cardiovascular diseases such as premature ventricular contractions for many years. However, pharmacological effects and underlying mechanisms of Xinmai'an tablet in protecting against myocardial ischemia-reperfusion injury (MIRI) were barely ever studied.

PURPOSE

To investigate the cardioprotective properties of Xinmai'an tablet against MIRI and the underlying molecular mechanism in rats.

METHODS

We initially established the UHPLC-QTRAP-MS/MS analysis method to ensure the controllable quality of Xinmai'an tablet. We further identified the cardioprotective effects of Xinmai'an tablet against MIRI using TTC staining, hematoxylin and eosin, echocardiography, the transmission electron microscope analysis, biochemical analysis, and ELISA. We then investigated whether the safeguarding effect of Xinmai'an tablet on MIRI model rats was related to AMPK/SIRT1/PGC-1α pathway via western blotting.

RESULTS

Xinmai'an tablet decreased myocardial infarct size; ameliorated cardiac function; alleviated myocardial and mitochondrial damage; and suppressed oxidative stress injury, vascular endothelial damage, and apoptosis response in MIRI model rats. Mechanistically, our results showed that Xinmai'an tablet can dramatically activate the AMPK/SIRT1/PGC-1αpathway and subsequently diminish mitochondrial oxidative stress damage. This was evidenced by increased ATP, Na+-K+-ATPase, and Ca2+-Mg2+-ATPase levels, upregulation of GLUT4, p-AMPK, SIRT1, and PGC-1α protein levels; and reduced GLUT1 protein level.

CONCLUSION

To the knowledge of the author of this article, this study is the first report of Xinmai'an tablet attenuating MIRI, potentially associated with the activation of the AMPK/SIRT1/PGC-1α pathway and subsequent reduction of mitochondrial oxidative stress damage. These findings reveal a novel pharmacological effect and mechanism of action of Xinmai'an tablet and highlight a promising therapeutic drug for ischemic cardiovascular diseases.

Correlation Analysis between Muskrat (Ondatra zibethicus) Musk and Traditional Musk

Muskrat musk is considered to be a potential substitute for traditional musk. However, little is known about the similarity between muskrat musk and musk, and whether it is related to muskrat age. In this study, muskrat musk (MR1, MR2, and MR3) were from 1, 2, and 3-year-old muskrats, respectively, and white musk (WM) and brown musk (BM) were picked from male forest musk deer. The results indicated that muskrat musk had higher similarity to WM than BM. Further research showed that RM3 had the highest matched degree with WM. By significantly different metabolite analysis, we found that 52 metabolites continue to increase from 1- to 3-year-old muskrats. In total, 7 and 15 metabolites were significantly decreased in RM1 vs. RM2 and RM2 vs. RM3, respectively. Meanwhile, 30 and 17 signaling pathways were observed from increased and decreased metabolites, respectively. The increased metabolites mainly entailed enrichment in amino acid biosynthesis and metabolism, steroid hormone biosynthesis, and fatty acid biosynthesis. In conclusion, muskrat musk from three-year-old muskrat is a relatively good substitute for white musk, and the result also implies that these biological processes of amino acid biosynthesis and metabolism, steroid hormone biosynthesis, and fatty acid biosynthesis are beneficial to the secretion of muskrat musk.