Neuroprotective Effects of Oxymatrine via Triggering Autophagy and Inhibiting Apoptosis Following Spinal Cord Injury in Rats

SIRT1-based therapy targets a gene program involved in mitochondrial turnover in a model of retinal neurodegeneration

Neurodegenerative diseases of the eye such as optic neuritis (ON) are hallmarked by retinal ganglion cell (RGC) loss and optic nerve degeneration leading to irreversible blindness. Therapeutic interventions enhancing expression or activity of SIRT1, an NAD+-dependent deacetylase, support, at least in part, survival of RGCs in the face of injury. Herein, we used mice with experimental autoimmune encephalomyelitis (EAE) which recapitulates axonal and neuronal damages characteristic of ON to identify gene regulatory networks affected by constitutive ubiquitous Sirt1 expression in SIRT1 knock-in mice and wild-type mice upon targeted adeno-associated virus (AAV)-mediated SIRT1 expression in RGCs. RNA seq data analysis showed that the most upregulated genes in EAE mouse retinas include those involved in inflammation, immune response, apoptosis, and mitochondrial turnover. The latter includes genes regulating mitophagy (e.g., Atg4), mitochondrial transport (e.g., Ipo- 6, Xpo- 6), and mitochondrial localization (e.g., Chrna4, Scn9a). The constitutive or RGC-targeted SIRT1 overexpression in EAE mice upregulated the expression of non-mitochondrial genes such as Ecel1 and downregulated the expression of mitophagy genes (e.g., Atg2b, Arifip1) which were upregulated by EAE alone. Thus, SIRT1 induces neuroprotection by, at least in part, balancing mitochondrial biogenesis and mitophagy and/or enhancing mitochondrial self-repair to preserve the bioenergetic capacity of RGCs.

Oxymatrine relieves non-alcoholic fatty liver disease by promoting sirtuin 1/adenosine 5'-monophosphate-activated protein kinase pathway and peroxisome proliferator activated receptor alpha-mediated hepatic fatty acid oxidation

Non-alcoholic fatty liver disease (NAFLD) is a liver disease without approved treatment. Oxymatrine (OMT) has protective effects in various liver diseases. We aimed to investigate the roles and mechanisms of OMT in NAFLD. NAFLD models were established using high-fat and high-sucrose diet-fed rats and oleic acid (OA)-stimulated hepatocytes, respectively. Then, OMT was used to treat the NAFLD models, with metformin as a positive control. Liver damage, lipid accumulation and hepatic lipid profile of NAFLD rats were assessed. Peroxisome proliferator activated receptor alpha (PPARα), sirtuin 1 (Sirt1)/adenosine 5'-monophosphate-activated protein kinase (AMPK) pathway- and fatty acid oxidation (acyl-CoA oxidase 1 and carnitine palmitoyltransferase 1A)-associated proteins were measured both in vivo and in vitro. Furthermore, hepatocytes were transfected with si-Sirt1 and oe-PPARα to verify the mechanisms of OMT in NAFLD. NAFLD rats supplemented with OMT displayed reduced liver damage and lipid accumulation. After OMT intervention, the liver lipid profile of NAFLD rats was changed greatly, most of the top differentially expressed lipid metabolites were triglyceride, moreover, diacylglycerol content was decreased in NAFLD rats. OMT activated the Sirt1/AMPK pathway and PPARα, and upregulated acyl-CoA oxidase 1 and carnitine palmitoyltransferase 1A expressions in NAFLD models. In vitro, OMT enhanced viability, and improved lipid accumulation in OA-stimulated hepatocytes. However, the protective functions of OMT in OA-exposed hepatocytes were offset by Sirt1 knockdown, while PPARα overexpression further counteracted the effects of Sirt1 knockdown. OMT could relieve NAFLD by promoting Sirt1/AMPK pathway- and PPARα-mediated hepatic fatty acid oxidation, indicating that OMT is a potential approach for NAFLD treatment.

Unlocking the Potential of Oxymatrine: A Comprehensive Review of Its Neuroprotective Mechanisms and Therapeutic Prospects in Neurological Disorders

Sophora flavescens, the source of oxymatrine, is gaining popularity due to its potential in neuroprotection and treatment of various neurological conditions like epilepsy, depression, Parkinson's, Alzheimer's and multiple sclerosis. Its natural occurrence and promising preliminary research highlight its ability to reduce nerve cell damage and inflammation, attributed to its antiapoptotic, antioxidant and anti-inflammatory properties. However, challenges like solubility, potential adverse effects and limited bioavailability hinder its full therapeutic utilization. Current strategies, including formulation optimization and innovative drug delivery systems, aim to enhance its efficacy and safety. Despite its potential, further research is necessary to overcome these obstacles and maximize its clinical effectiveness. Conclusively, oxymatrine demonstrates distinct neuroprotective properties, offering unique advantages over other agents currently being studied or used in clinical practice for neurological disorders. nevertheless, additional study is necessary to surmount current obstacles and maximize its effectiveness for clinical settings. This study provides a comprehensive overview of oxymatrine's neuroprotective mechanisms and therapeutic potential while emphasizing the need for continued investigation and development for practical clinical application.

Oxymatrine Improves Oxidative Stress-Induced Senescence in HT22 Cells and Mice via the Activation of AMP-Activated Protein Kinase

The accumulation of oxidative stress is one of the important factors causing cellular senescence. Oxymatrine (OM) is a natural quinolizidine alkaloid compound known for its antioxidant effects. This study aimed to investigate the anti-senescence potential of OM through oxidative stress-induced in vitro and in vivo models. By treating 600 μM of H2O2 to the HT22 mouse hippocampal neuronal cell line and by administering 150 mg/kg D-galactose to mice, we generated oxidative stress-induced senescence models. After providing 1, 2, and 4 μg/mL of OM to the HT22 mouse cell line and by administering 50 mg/kg OM to mice, we evaluated the enhancing effects. We evaluated different senescence markers, AMPK activity, and autophagy, along with DCFH-DA detection reaction and behavioral tests. In HT22 cells, OM showed a protective effect. OM, by reducing ROS and increasing p-AMPK expression, could potentially reduce oxidative stress-induced senescence. In the D-Gal-induced senescence mouse model, both the brain and heart tissues recovered AMPK activity, resulting in reduced levels of senescence. In neural tissue, to assess neurological recovery, including anxiety symptoms and exploration, we used a behavioral test. We also found that OM decreased the expression level of receptors for advanced glycation end products (RAGE). In heart tissue, we could observe the restoration of AMPK activity, which also increased the activity of autophagy. The results of our study suggest that OM ameliorates oxidative stress-induced senescence through its antioxidant action by restoring AMPK activity.

AQP4 is an Emerging Regulator of Pathological Pain: A Narrative Review

Pathological pain presents significant challenges in clinical practice and research. Aquaporin-4 (AQP4), which is primarily found in astrocytes, is being considered as a prospective modulator of pathological pain. This review examines the association between AQP4 and pain-related diseases, including cancer pain, neuropathic pain, and inflammatory pain. In cancer pain, upregulated AQP4 expression in tumor cells is linked to increased pain severity, potentially through tumor-induced inflammation and edema. Targeting AQP4 may offer therapeutic strategies for managing cancer pain. AQP4 has also been found to play a role in nerve damage. Changes in AQP4 expression have been detected in pain-related regions of the brain and spinal cord; thus, modulating AQP4 expression or function may provide new avenues for treating neuropathic pain. Of note, AQP4-deficient mice exhibit reduced chronic pain responses, suggesting potential involvement of AQP4 in chronic pain modulation, and AQP4 is involved in pain modulation during inflammation, so understanding AQP4-mediated pain modulation may lead to novel anti-inflammatory and analgesic therapies. Recent advancements in magnetic resonance imaging (MRI) techniques enable assessment of AQP4 expression and localization, contributing to our understanding of its involvement in brain edema and clearance pathways related to pathological pain. Furthermore, targeting AQP4 through gene therapies and small-molecule modulators shows promise as a potential therapeutic intervention. Future research should focus on utilizing advanced MRI techniques to observe glymphatic system changes and the exchange of cerebrospinal fluid and interstitial fluid. Additionally, investigating the regulation of AQP4 by non-coding RNAs and exploring novel small-molecule medicines are important directions for future research. This review shed light on AQP4-based innovative therapeutic strategies for the treatment of pathological pain. Dark blue cells represent astrocytes, green cells represent microglia, and red ones represent brain microvasculature.