Quercetin alleviates kainic acid-induced seizure by inhibiting the Nrf2-mediated ferroptosis pathway

Status epilepticus alters hippocampal ultrastructure in kainic acid rat model

Kainic acid (KA) model of epilepsy is a reliable tool to study temporal lobe epilepsy (TLE), the most common type of partial epilepsy in adults. Substantial body of data suggest that the KA-induced status epilepticus (SE) leads to several molecular and structural changes in the hippocampus, including sclerosis, sprouting of mossy fiber, reorganization of inter-neuronal networks, alterations in neuropeptide signaling, gliosis, and synaptic transmission dysregulation. However, no details on the ultrastructural changes, especially in relationship to synapses are available. This information is important in providing a comprehensive understanding of subtle changes that occur in this debilitating disease. Thus, in this study, applying electron-microscopic morphometric analysis, we evaluated the ultrastructural effects of KA on the CA1 region of the hippocampus, an area intimately involved in SE. The total number of synaptic vesicles (SVs), the number of docking SVs, the length of synapse active zone (AZ) and the number and area of presynaptic and postsynaptic mitochondria in axo-dendritic (excitatory) synapses were measured at 24 h, and 8 and 21 days after KA administration. Results indicate a decrease in the total number and docking of SVs, an increase in the length of AZ and the number and area of presynaptic and postsynaptic mitochondria, which were more prominent at 8 days after KA injection. The findings suggest a time-dependent ultrastructural changes in CA1 region of the hippocampus in an animal model of focal epilepsy.

The Keap1/Nrf2/ARE/HO-1 axis in epilepsy: Crosstalk between oxidative stress and neuroinflammation

Epilepsy is a complex neurological disorder characterized by recurrent seizures, which are driven by multifaceted pathophysiological mechanisms, including oxidative stress and neuroinflammation. Despite advancements in anti-seizure medications (ASMs), a significant proportion of patients remain resistant to treatment, highlighting the need for novel therapeutic strategies. This review focuses on the Kelch-like ECH-associated protein 1 (Keap1) / Nuclear factor erythroid 2-related factor 2 (Nrf2) / Antioxidant Response Element (ARE) / Heme Oxygenase-1 (HO-1) axis as a promising target for neuroprotection in epilepsy. We explored the intricate interactions between Keap1 and Nrf2 under homeostatic conditions and how oxidative stress disrupts this balance, triggering Nrf2 activation. This review details the subsequent process of Nrf2 nuclear translocation, its binding to AREs, and the induction of cytoprotective gene expression, which collectively orchestrate a robust cellular defense response. Special emphasis is placed on HO-1, a key effector of Nrf2-mediated neuroprotection, highlighting its enzymatic function and protective mechanisms, including antioxidant, anti-inflammatory, and anti-apoptotic effects. Additionally, the review examines HO-1's role in mitigating seizure-induced neuronal damage. However, challenges remain, including variability in therapeutic responses, gaps in long-term clinical validation, and the need for standardized protocols. Future research should focus on biomarkers for personalized treatment, advanced imaging, and genetic tools to explore the Keap1/Nrf2/ARE/HO-1 axis in greater depth. Future studies should focus on overcoming the challenges of translating preclinical findings into clinical applications and exploring the long-term effects of targeting this pathway in epilepsy treatment.

Edaravone alleviates sepsis-induced diaphragmatic dysfunction via Sirt1/Nrf2 pathway

BACKGROUND

The mechanisms underlying the development of sepsis-induced diaphragmatic dysfunction (SIDD) are poorly understood. Activation of the SIRT1/Nrf2 signaling pathway can attenuate oxidative stress damage in skeletal muscle injury. The present study aimed to validate the hypothesis that edaravone (ED) can improve SIDD through modulation of the SIRT1/Nrf2 signaling pathway and to explore the underlying mechanisms.

METHODS

Animal models (mice) were constructed using the cecal ligation and puncture (CLP) method, while the C2C12 cells were stimulated by lipopolysaccharide (LPS). The diaphragmatic function was accessed by diaphragm ultrasonography. We examined the expression levels of proteins involved in the SIRT1/Nrf2 pathway (Sirt1, Nrf2, and HO-1), oxidative stress markers (SOD, ROS, and GPX4), and muscle atrophy-related proteins (MuRF1 and Atrogin-1) to test the role of ED in SIDD.

RESULTS

We found that sepsis-induced a significant decrease in both diaphragmatic excursion and contractile velocity. Administration of ED (5 mg/kg) improved the diaphragmatic function in mice. Moreover, sepsis mice showed increased levels of oxidative stress markers and muscle atrophy-related proteins and a down-regulated pathway of SIRT1/Nrf2. The intervention of ED could modulate the SIRT1/Nrf2 pathway, which in turn protects the diaphragm from SIDD. Similar findings were also observed in vitro experiments with small interfering RNAs.

CONCLUSIONS

Edaravone was demonstrated to potentially alleviate SIDD by activating the SIRT1/Nrf2 pathway.

Tandem Dual-Ratiometric SERS Probe Enables Raman Imaging of Neurological pH Fluctuations in Epilepsy

An imbalance of brain pH is closely associated with biochemical reactions, ion regulation, and electrical activity, serving as a hallmark for various neurological disorders. High-resolution imaging of pH fluctuations in brain disease is crucial for understanding pathological processes. However, current pH probes are inadequate for this purpose due to poor blood-brain barrier (BBB) penetration or insufficient specificity. Herein, we reported a tandem dual-ratiometric surface-enhanced Raman scattering (SERS) probe, RHP@AuS, capable of crossing the BBB to address these challenges. RHP@AuS leveraged dendrimers for the facile one-step synthesis of SERS probes, significantly enhancing signal intensity and reproducibility. RHP@AuS can be sequentially activated by neuroinflammation-associated H2O2 and pH, exhibiting highly selective ratiometric responses to pH fluctuations in brain disease. Dynamic SERS imaging revealed that during neuronal epileptic activity, inflammation increased and local pH dropped sharply to around 6.6. Building on these findings, a drug combination with dual neuroinflammation-mitigating and pH-regulating properties was developed, effectively alleviating epilepsy in mouse models. This study opens new avenues for developing imaging probes for the brain and deepens our understanding of the roles of pH in neurological disorders.

Scutellarein ameliorates pulmonary arterial hypertension via sirtuin 1 mediated deacetylation of nicotinamide nucleotide transhydrogenase

Scutellarein (Sc), a natural flavonoid, holds potential for treating pulmonary arterial hypertension (PAH), yet its mechanisms remain unexplored. This study investigated Sc's therapeutic effects and underlying pathways in PAH. In vivo experiments demonstrated that Sc significantly attenuated right ventricular hypertension, pulmonary arterial remodeling, αSMA expression, and vascular inflammation in PAH models. In vitro, Sc suppressed hypoxia-induced proliferation, migration, inflammation, and pyroptosis in human pulmonary artery smooth muscle cells (HPASMCs). Mechanistically, Sc activated the SIRT1/NAD+ axis to restore mitochondrial homeostasis: it upregulated SIRT1 expression and elevated NAD+ levels by promoting SIRT1-mediated deacetylation of nicotinamide nucleotide transhydrogenase (NNT), thereby enhancing NNT activity. Elevated NAD+ further activated SIRT1, forming a self-reinforcing SIRT1/NNT/NAD+ feedback loop that mitigated hypoxia-induced mitochondrial dysfunction. This study identifies Sc as a novel regulator of the SIRT1-dependent NNT deacetylation pathway, which stabilizes NAD+ homeostasis to counteract HPASMCs dysregulation in PAH. These findings highlight Sc's potential as a therapeutic candidate for PAH, offering insights into targeting mitochondrial-metabolic pathways for vascular remodeling diseases.

Curcumin induces mitochondrial dysfunction-associated oxidative DNA damage in ovarian cancer cells

Resistance to chemotherapeutic agents is a critical challenge for the clinical management of ovarian cancer. While curcumin has been reported to possess anti-cancer properties, how it exerts its anti-neoplastic effect on ovarian cancer cells remains to be explored. We here characterized the fate of human ovarian cancer cell lines HO8910 and OVCAR3 treated with curcumin. Cell proliferation, cell death, mitochondrial function, oxidative damage and tumor formation in nude mice were examined. Significant inhibition of proliferation and induction of apoptosis were observed in ovarian cells treated with curcumin. The cancer cells exhibit cell cycle arrest at G2/M phase, mitochondrial accumulation, mitochondrial oxidative stress and high level of DNA damage after curcumin treatment. This effect of curcumin is independent of the BRCA mutation status. Curcumin-induced proliferation inhibition and apoptosis were effectively attenuated by the application of antioxidant N-acetylcysteine (NAC), suggesting that curcumin exerts its anti-cancer effect by inflicting oxidative stress. Curcumin applied at 200 mg/kg intraperitoneal infusion daily also inhibited the growth, oxidative damage, and mitochondrial accumulation of tumor xenografts in vivo. Together, the results indicate that curcumin can exert its anti-tumor effect via inducing mitochondrial dysfunction-associated oxidative DNA damage and can be potentially used in combination with other DNA repair-interfering therapeutics, such as PARP inhibitor, in the treatment of ovarian cancer.

Kynurenine Pathway in Epilepsy: Unraveling Its Role in Glutamate Excitotoxicity, GABAergic Dysregulation, Neuroinflammation, and Mitochondrial Dysfunction

Epilepsy is a chronic noncommunicable neurological disorder characterized by recurrent seizures and ranks as the seventh most prevalent neurological disease globally. According to the Global Burden of Disease report, 3.40 billion people were affected by epilepsy in 2021. The pathophysiology of epilepsy states that a disturbed balance between excitatory and inhibitory signaling at the synaptic level, which can cause seizure activity, is similar across epilepsies and includes mitochondrial dysfunction, neuroinflammation, and kynurenine metabolites such as kynurenic acid and quinolinic acid. The kynurenine pathway (KP) is the major metabolic pathway in which tryptophan (TRP) is the key precursor which is further converted into a variety of neuroactive substances that can have both neurotoxic metabolites (Quinolinic acid) and neuroprotective metabolites such as kynurenic acid, and picolinic acid. KP plays a significant role in the brain such as the metabolism of TRP, the production of metabolites, and its impact on aging. However, higher concentrations of kynurenine and its metabolites, such as quinolinic acid may increase the frequency and intensity of seizures, and dysregulation of the KP has been linked to the pathophysiology of epilepsy. Concurrently, glutamate and GABA signaling is altered by neuroinflammatory processes linked to epilepsy, which results in excitotoxic neuronal damage. This review aims to provide novel therapeutic strategies that might improve the prognosis of individuals with epilepsy and related disorders by elucidating the mechanisms underlying KP dysregulation in these circumstances. To develop targeted therapies for CNS disorders characterized by inflammation and seizures, it is essential to understand how kynurenine metabolites both promote and prevent excitotoxicity.

Potential role of SIRT1 in cell ferroptosis

Ferroptosis is a novel form of cell death that uniquely requires iron and is characterized by iron accumulation, the generation of free radicals leading to oxidative stress, and the formation of lipid peroxides, which distinguish it from other forms of cell death. The regulation of ferroptosis is extremely complex and is closely associated with a spectrum of diseases. Sirtuin 1 (SIRT1), a NAD + -dependent histone deacetylase, has emerged as a pivotal epigenetic regulator with the potential to regulate ferroptosis through a wide array of genes intricately associated with lipid metabolism, iron homeostasis, glutathione biosynthesis, and redox homeostasis. This review provides a comprehensive overview of the specific mechanisms by which SIRT1 regulates ferroptosis and explores its potential therapeutic value in the context of multiple disease pathologies, highlighting the significance of SIRT1-mediated ferroptosis in treatment strategies.

Role and therapeutic considerations of SIRT1 in epilepsy

Epilepsy is a primary study focus for scientists worldwide due to its prevalence and poor prognosis. Silent information regulator 1 (SIRT1), a nicotinamide adenine dinucleotide-dependent deacetylase, is becoming increasingly recognized for its critical role in the pathophysiology and progression of epilepsy. The treatment of epilepsy remains challenging despite the discovery of numerous factors that contribute to the development of several beneficial medications. In recent years, many microRNAs have been linked to the progression of epilepsy because they target SIRT1 mRNA. SIRT1, which protects from epilepsy, has been reported to be upregulated by several natural compounds and their derivatives. This review will summarize the latest findings about SIRT1's role in epilepsy. Results from the literature indicate that SIRT1 is a promising target for epilepsy therapy.

Effects of melatonin on the pharmacokinetics and amino acid metabolism profile of vigabatrin in rats

OBJECTIVES

Investigating the effect of melatonin (MLT) on the pharmacokinetics and related neurotransmitter and amino acid metabolism of vigabatrin (VGB) in epileptic rats in vivo.

METHODS

High performance liquid chromatography was used to examine the pharmacokinetics and tissue distribution of VGB after intragastric administration dosing (50，100，200) mg/kg singly or in combination with melatonin (20 mg/kg) in rats. The single-compartment model of first-order elimination was fitted with the nonlinear mixed-effect model of first-order estimation. Targeting metabolomics were used to measure and analyze the amino acid levels in the hippocampus of kainic acid (KA)-induced epileptic rats treated with VGB alone or coupled melatonin.

RESULTS

Melatonin significantly alters the pharmacokinetics of VGB, primarily by lengthening the elimination t1/2, Tmax, MRT and Vz/F, and decreasing the Cmax of both vigabatrin R(-) enantiomer (R-VGB) and vigabatrin S(+) enantiomer (S-VGB). Moreover, the concentrations of R-VGB and S-VGB were increased significantly in the lung and spleen of VGB + MLT group at 15 min compared with that of the VGB group. At 1 h, S-VGB levels increased significantly in spleen. At 4 h, the levels of S-VGB in the hippocampus and R-VGB in the prefrontal cortex increased significantly. Results of targeted metabolomics experiment showed that compared with control group, the level of aminobutyric acid/glutamate (GABA/Glu) in hippocampus of KA-induced epileptic rats was decreased, while glutamate/glutamine (Glu/Gln), tyrosine, dopamine, 3-methoxytyramine, tryptophan, 5-hydroxytryptamine, arginine and phenylalanine were significantly increased. These elevated levels of neurotransmitters and amino acids were decreased in VGB- and VGB + MLT treated group.

CONCLUSIONS

MLT affected the pharmacokinetics and tissue distribution of VGB in rats, prolonging its elimination time and improving the tissue distribution. Moreover, it might help VGB improve the imbalance of neurotransmitters and amino acids in the hippocampus of epileptic rats.

Identification and validation of diagnostic biomarkers for temporal lobe epilepsy related to ferroptosis and potential therapeutic targets

Ferroptosis pathway activation is potentially correlated with temporal lobe epilepsy (TLE). However, the diagnostic significance and mechanism of ferroptosis-related genes (FRGs) in TLE require further investigation. A comprehensive analysis of the GSE134697 dataset from the Gene Expression Omnibus (GEO) database using Weighted gene co-expression network analysis (WGCNA) identified 3,212 differentially expressed genes (DEGs) between temporal lobe epilepsy (TLE) and control groups, with a critical focus on the turquoise module. Through intersection of DEGs and key module genes, correlation analyses with functional-related genes (FRG), protein-protein interactions (PPI), least absolute shrinkage and selection operator (LASSO), and machine learning methods, five potential biomarkers of ferroptosis (CBS, SHMT1, RIN3, QDPR, and PLPP4) were isolated. A nomogram was constructed using these markers, and enrichment analyses revealed their links to T-cell activation, allograft rejection, and glial differentiation. Variations in 13 immune cell types were also noted. Upregulation of CBS, RIN3, QDPR, and PLPP4 in TLE was confirmed through RT-qPCR and Western blot assays. Additionally, five SHMT1-targeting and one CBS-targeting drugs were predicted using the Drug-Gene Interaction Database (DGIdb). These findings provide new insights into the potential pathogenesis of TLE and suggest new targets for future research.

Astaxanthin Inhibits Ferroptosis of Hippocampal Neurons in Kainic Acid-Induced Epileptic Mice by Activating the Nrf2/GPX4 Signaling Pathway

BACKGROUND

Epilepsy, a prevalent neurological disorder, is distinguished by episodic abnormal discharges of neurons within the brain, resulting in transient brain dysfunction. Prior research has identified a novel form of cell death termed ferroptosis, which is intricately linked to the initiation and progression of epilepsy. It has been demonstrated that astaxanthin (AST) can inhibit ferroptosis by enhancing the activity of nuclear factor erythroid 2-related factor 2 (Nrf2), thereby providing cytoprotection. Therefore, this study aims to investigate whether AST can alleviate neuronal ferroptosis in epilepsy by activating the Nrf2/GPX4 pathway, thereby exerting a neuroprotective effect.

METHODS

By constructing a kainic acid (KA)-induced epilepsy mouse model and a KA-induced HT22 cell model, we employed behavioral testing, Western blot analysis, quantitative real-time reverse transcription qRT-PCR, ferroptosis-related assay kits, immunofluorescence staining, and other methods. These methodologies were utilized to investigate the protective effects and underlying mechanisms of AST on ferroptosis in KA-induced epileptic mice and HT22 neurons.

RESULTS

Our results demonstrate that AST pretreatment alleviates KA-induced epileptic behaviors and cognitive impairments in mice and mitigates ferroptosis indicators such as lipid peroxidation and mitochondrial morphological alterations. This neuroprotective effect appears to be mediated by the activation of the Nrf2/GPX4 signaling axis. In vitro studies further revealed that AST confers neuroprotection against KA-induced HT22 neuronal cell death, an effect that is abrogated by an Nrf2 inhibitor. Hence, the neuroprotective properties of AST are significantly associated with the modulation of the Nrf2-mediated ferroptosis pathway, as corroborated by bioinformatics analyses.

CONCLUSION

The AST effectively inhibits neuronal ferroptosis in both in vivo and in vitro epilepsy models via the Nrf2/GPX4 pathway. This finding suggests that AST holds promise as a potential therapeutic agent for the treatment of epilepsy.

Model organisms for investigating the functional involvement of NRF2 in non-communicable diseases

Non-communicable chronic diseases (NCDs) are most commonly characterized by age-related loss of homeostasis and/or by cumulative exposures to environmental factors, which lead to low-grade sustained generation of reactive oxygen species (ROS), chronic inflammation and metabolic imbalance. Nuclear factor erythroid 2-like 2 (NRF2) is a basic leucine-zipper transcription factor that regulates the cellular redox homeostasis. NRF2 controls the expression of more than 250 human genes that share in their regulatory regions a cis-acting enhancer termed the antioxidant response element (ARE). The products of these genes participate in numerous functions including biotransformation and redox homeostasis, lipid and iron metabolism, inflammation, proteostasis, as well as mitochondrial dynamics and energetics. Thus, it is possible that a single pharmacological NRF2 modulator might mitigate the effect of the main hallmarks of NCDs, including oxidative, proteostatic, inflammatory and/or metabolic stress. Research on model organisms has provided tremendous knowledge of the molecular mechanisms by which NRF2 affects NCDs pathogenesis. This review is a comprehensive summary of the most commonly used model organisms of NCDs in which NRF2 has been genetically or pharmacologically modulated, paving the way for drug development to combat NCDs. We discuss the validity and use of these models and identify future challenges.

Lactate Ameliorates Kainic Acid-Induced Neuroinflammation and Cognitive Impairment via the Chemokine Signaling Pathway in Mice

Purpose

Lactate, previously considered a metabolic waste product, has been shown to have neuroprotective potential. This study aims to investigate the impact of lactate intervention and its underlying mechanisms on epilepsy.

Methods

HT22 cells were stimulated with glutamate to construct an excitotoxicity cell model. An acute epilepsy model was established in mice by kainic acid induction. The neuronal damage, microglial activation, inflammatory responses, and functional changes were determined by TUNEL assays, immunohistochemistry, quantitative real-time polymerase chain reaction and behavioral tests. The differentially gene expression and functional enrichment were analyzed with RNA sequencing.

Results

The in vitro lactate intervention reduced the number of apoptotic cells, the release of inflammatory factors, and the expression of vesicular glutamate transporter 1. In mice with acute epilepsy, lactate treatment mitigated neuronal damage, microglial activation, and inflammatory responses in the hippocampus and ameliorated anxiety-like behavior and cognitive impairment.

Conclusion

Lactate exerts therapeutic effects on epilepsy through the chemokine signaling pathway. The neuroinflammation is an important contributor to cognitive impairment. Targeting inflammatory pathways is a promising strategy for improving the prognosis of epilepsy.

Anti-ferroptotic effects of natural polyphenols in nervous system injury: a narrative literature review

BACKGROUND

Recent studies have shown that ferroptosis, a newly identified regulated cell death characterized by increased lipid peroxidation and accumulation of toxic lipid peroxides, is closely related to the pathophysiological processes of nervous system diseases which can be inhibited with iron chelators, lipophilic antioxidants, and lipid peroxidation inhibitors.

OBJECTIVE

To review the current evidence on the efficacy of various natural polyphenols in nervous system injury.

METHODS

The data selected for this review were collected by searching the MEDLINE/PubMed, Web of Science, Scopus, and Google Scholar database for articles published in English between 2000 and 2024 using the following terms: cell death, regulated cell death, ferroptosis, lipid peroxides, iron, and glutathione peroxidase.

RESULTS

Natural polyphenols have been found to have some protective effects against nervous system disorders, which are attributed to a variety of biological properties, particularly antioxidant, immunomodulatory, and anti-inflammatory effects. The preclinical studies conducted on the use of the most common dietary polyphenols, including resveratrol, EGCG, curcumin, quercetin, gastrodin, baicalein & baicalin, carthamin, galangin, puerarin, morachalcone, and carnosic acid with the molecular mechanisms have been discussed. On the other hand, the results of a few clinical studies emphasize the primary role of iron in neuronal degeneration following some of nervous system injury.

CONCLUSION

Some of the findings indicated that natural polyphenols as antioxidant supplements have anti-ferroptotic effects in nervous system disorders.

In defence of ferroptosis

Rampant phospholipid peroxidation initiated by iron causes ferroptosis unless this is restrained by cellular defences. Ferroptosis is increasingly implicated in a host of diseases, and unlike other cell death programs the physiological initiation of ferroptosis is conceived to occur not by an endogenous executioner, but by the withdrawal of cellular guardians that otherwise constantly oppose ferroptosis induction. Here, we profile key ferroptotic defence strategies including iron regulation, phospholipid modulation and enzymes and metabolite systems: glutathione reductase (GR), Ferroptosis suppressor protein 1 (FSP1), NAD(P)H Quinone Dehydrogenase 1 (NQO1), Dihydrofolate reductase (DHFR), retinal reductases and retinal dehydrogenases (RDH) and thioredoxin reductases (TR). A common thread uniting all key enzymes and metabolites that combat lipid peroxidation during ferroptosis is a dependence on a key cellular reductant, nicotinamide adenine dinucleotide phosphate (NADPH). We will outline how cells control central carbon metabolism to produce NADPH and necessary precursors to defend against ferroptosis. Subsequently we will discuss evidence for ferroptosis and NADPH dysregulation in different disease contexts including glucose-6-phosphate dehydrogenase deficiency, cancer and neurodegeneration. Finally, we discuss several anti-ferroptosis therapeutic strategies spanning the use of radical trapping agents, iron modulation and glutathione dependent redox support and highlight the current landscape of clinical trials focusing on ferroptosis.

Nrf2 and Ferroptosis: Exploring Translational Avenues for Therapeutic Approaches to Neurological Diseases

Nrf2, a crucial protein involved in defense mechanisms, particularly oxidative stress, plays a significant role in neurological diseases (NDs) by reducing oxidative stress and inflammation. NDs, including Alzheimer's, Parkinson's, Huntington's, amyotrophic lateral sclerosis, stroke, epilepsy, schizophrenia, depression, and autism, exhibit ferroptosis, iron-dependent regulated cell death resulting from lipid and iron-dependent reactive oxygen species (ROS) accumulation. Nrf2 has been shown to play a critical role in regulating ferroptosis in NDs. Age-related decline in Nrf2 expression and its target genes (HO-1, Nqo-1, and Trx) coincides with increased iron-mediated cell death, leading to ND onset. The modulation of iron-dependent cell death and ferroptosis by Nrf2 through various cellular and molecular mechanisms offers a potential therapeutic pathway for understanding the pathological processes underlying these NDs. This review emphasizes the mechanistic role of Nrf2 and ferroptosis in multiple NDs, providing valuable insights for future research and therapeutic approaches.

Role of miRNA regulation in IGFBP-2 overexpression and neuronal ferroptosis: Insights into the Nrf2/SLC7A11/GPX4 pathway in Alzheimer's disease

Alzheimer's disease (AD) is a common neurodegenerative disease with pathological features including amyloid plaque deposits and neurofibrillary tangles. In this study, the expressions of miRNA, IGFBP-2 and neuronal ferritin were detected by qPCR, Western blot and immunohistochemistry. The regulatory effects of miRNA on IGFBP-2 and neuronal ferritin were further verified by intervention experiments with miRNA mimics and inhibitors. Double luciferase reporter gene assay and RNA immunoprecipitation were used to investigate the interaction between miRNA and target genes. Finally, the effect of miRNA on Nrf2/SLC7A11/GPX4 pathway was evaluated by antioxidant enzyme activity and oxidative stress marker detection. The overexpression of IGFBP-2 was found to be significantly increased with the deposition of neuronal ferritin. Expression levels of specific mirnas were significantly down-regulated in AD models and negatively correlated with IGFBP-2 and neuronal ferritin expression. Intervention experiments with miRNA mimics and inhibitors have confirmed that these mirnas can regulate the expression of IGFBP-2 and neuronal ferritin. Further studies revealed that these mirnas affect antioxidant enzyme activity and oxidative stress levels by targeting key genes in the Nrf2/SLC7A11/GPX4 pathway, thereby regulating the deposition of neuronal ferritin.

Environmental Pollutants and Epilepsy: Is It Nrf or Nothing?

PM2.5 Exposure Exacerbates Seizure Symptoms and Cognitive Dysfunction by Disrupting Iron Metabolism and the Nrf2-Mediated Ferroptosis Pathway Mei H, Wu D, Yong Z, Cao Y, Chang Y, Liang J, Jiang X, Xu H, Yang J, Shi X, Xie R, Zhao W, Wu Y, Liu Y. Sci Total Environ 2024;910:168578. In recent years, air pollution has garnered global attention due to its ability to traverse borders and regions, thereby impacting areas far removed from the emission sources. While prior studies predominantly focused on the deleterious effects of PM2.5 on the respiratory and cardiovascular systems, emerging evidence has highlighted the potential risks of PM2.5 exposure to the central nervous system. Nonetheless, research elucidating the potential influences of PM2.5 exposure on seizures, specifically in relation to neuronal ferroptosis, remains limited. In this study, we investigated the potential effects of PM2.5 exposure on seizure symptoms and seizures-induced hippocampal neuronal ferroptosis. Our findings suggest that seizure patients residing in regions with high PM2.5 levels are more likely to disturb iron homeostasis and the Nrf2-dependent ferroptosis pathway compared to those living in areas with lower PM2.5 levels. The Morris Water Maze test, Racine scores, and EEG recordings in epileptic mice suggest that PM2.5 exposure can exacerbate seizure symptoms and cognitive dysfunction. Neurotoxic effects of PM2.5 exposure were demonstrated via Nissl staining and CCK-8 assays. Direct evidence of PM2.5-induced hippocampal neuronal ferroptosis was provided through TEM images. Additionally, increased Fe2+ and lipid ROS levels indirectly supported the notion of PM2.5-induced hippocampal ferroptosis. Therefore, our study underscores the necessity of preventing and controlling PM2.5 levels, particularly for patients with seizures.

Analysis of the role of PANoptosis in intervertebral disk degeneration via integrated bioinformatics analysis and experimental validation

Intervertebral disc degeneration (IVDD) is an age-related orthopedic degenerative disease characterized by recurrent episodes of lower back pain, and death of nucleus pulposus cells (NPCs) has been identified as a key factor in the pathophysiological process of IVDD episodes. Recent studies have shown that " PANapoptosis ", a newly characterized form of cell death, has emerged as an important factor contributing to the development of several diseases. However, studies on the specific mechanisms of its role in the development of IVDD are lacking. The aim of this study was to explore the characterization of PANoptosis in IVDD and to identify potential biomarkers and therapeutic targets as well as therapeutic agents. We constructed a PANoptosis gene set, based on the GEO database, and used weighted gene co-expression network analysis (WGCNA) and differential expression analysis to identify PANoptosis genes associated with the pathophysiological process of IVDD episodes by Gene Set Enrichment Analysis (GSEA), immune infiltration, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) to explore the underlying biological mechanisms of PANoptosis and its role in IVDD. Comprehensive bioinformatics analysis showed that seven key genes (APAF1, MEFV, NLRP3, TNF, GSDMD, AIM2, and IRF1) of PANoptosis have good diagnostic value. In addition, we predicted potential therapeutic agents, among which Andrographolide (AG) had the highest correlation and binding affinity to the target. Finally, we performed Western blotting and quantitative real-time polymerase chain reaction (qRT-PCR) assays, molecular docking, and cell flow to validate the expression of PANoptosis-related genes and the therapeutic effect of AG. We further divided SD rats into sham-operated, IVDD model, and Andrographolide-treated groups, administered AG at 50 mg/kg via gavage for one month, and observed significant therapeutic effects through HE staining. This study identifies key PANoptosis genes and demonstrates the potential of AG as a therapeutic agent for IVDD.

Integrated network pharmacology and transcriptomics to explore the mechanism of compound Dihuang granule (CDG) protects dopaminergic neurons by regulating the Nrf2/HMOX1 pathway in the 6-OHDA/MPP+-induced model of Parkinson's disease

BACKGROUND

Parkinson's disease (PD) is a degenerative neurological disease that worsens over time. Ferroptosis has been proven to contribute to PD pathogenesis. CDG exhibits neuroprotective effects. However, CDG's potential mechanism in PD therapy remains uncertain.

PURPOSE

The purpose of this investigation is to ascertain the specific molecular mechanisms of CDG against neuronal ferroptosis and present an alternative option for PD management.

METHODS

Network pharmacology along with LC-MS were used to identify possible targets and candidate pathways. Then RNA-sequencing combined in the in vitro and in vivo experiments were utilized to validate these findings.

RESULTS

According to network pharmacology prediction, NFE2L2, HMOX1 and PTGS2 may be the key genes for ferroptosis in PD. In the in vivo experiments, CDG ultimately improved the neurobehavior of PD rats by alleviating the damage of dopamine neurons, decreasing the levels of MDA, ROS and Fe2+, increasing the GSH level, inhibiting ferroptosis by decreasing ACSL4, TF, and PTGS2 expression levels, and increasing the GPX4, FTH, Nrf2, and HMOX1 levels. RNA-seq analysis showed the differential genes in Model and CDG group were all enriched in Nrf2 and HMOX1, and the enrichment analysis of these differential genes showed they were closely related to the ferroptosis. Subsequently, in vitro experiments, the CDG, OE-Nrf2 and OE-HMOX1 group showed more active cell vitality, with decreasing levels of MDA, ROS, Fe2+, ACSL4, TF and PTGS2, and increasing level GSH, GPX4, FTH, Nrf2 and HMOX1.

CONCLUSION

CDG has a neuroprotective involvement in alleviating ferroptosis by regulating the Nrf2/HMOX1 pathway. Moreover, this research offers pharmacological evidence supporting the applications of CDG for treating PD.

Biochanin A inhibits excitotoxicity-triggered ferroptosis in hippocampal neurons

Excitatory neurotransmitter-induced neuronal ferroptosis has been implicated in multiple neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease. Although there are several reports pertaining to the pharmacological activities of biochanin A, the effects of this isoflavone on excitotoxicity-triggered neuronal ferroptosis remain unclear. In this study, we demonstrate that biochanin A inhibits ferroptosis of mouse hippocampal neurons induced by glutamate or the glutamate analog, kainic acid. Biochanin A significantly inhibited accumulation of intracellular iron and lipid peroxidation in glutamate- or kainic acid-treated mouse hippocampal neurons. Furthermore, biochanin A regulated the level of glutathione peroxidase 4, a master regulator of ferroptosis, by modulating its autophagy-dependent degradation. We observed that biochanin A reduced the glutamate-induced accumulation of intracellular iron by regulating expression of iron metabolism-related proteins including ferroportin-1, divalent metal transferase 1, and transferrin receptor 1. Taken together, these results indicate that biochanin A effectively inhibits hippocampal neuronal death triggered by glutamate or kainic acid. Our study is the first to report that biochanin A has therapeutic potential for the treatment of diseases associated with hippocampal neuronal death, particularly ferroptosis induced by excitatory neurotransmitter.

Investigating the potential risk of cadmium exposure on seizure severity and anxiety-like behaviors through the ferroptosis pathway in epileptic mice: An integrated multi-omics approach

Cadmium, a toxic heavy metal from industrial activities, poses a neurotoxic risk, especially to children. While seizures are common in children, the link between cadmium and seizure activity is unclear. Ferroptosis, an iron-dependent cell death, is key in seizure-induced hippocampal damage and related anxiety. This study aims to elucidate these mechanisms and assess the broader implications of cadmium exposure. Our research contributes in three significant areas: Firstly, through a combination of observational studies in long-term cadmium-exposed workers, Mendelian randomization analysis, NHANES analysis, urinary metabolomics, and machine learning analysis, we explored the impact of long-term cadmium exposure on inflammatory cytokines, ferroptosis-related gene expression, and lipid and iron metabolism. Secondly, by harnessing public databases for human disorders and metal-associated gene targets, alongside therapeutic molecular analyses, we identified critical human gene targets for cadmium toxicity in seizures and proposed melatonin as a promising therapeutic agent. Finally, utilizing mouse behavioral assays, T2 MRI, and MRS, we provide evidence of how prolonged cadmium exposure disrupts iron and lipid metabolism in the brain, triggering ferroptosis in the hippocampus.

Quercetin Alleviates Perimenopausal Depression Induced by Ovariectomy Combined with Chronic Unpredictable Mild Stress Through Regulating Serum Elements and Inhibiting Ferroptosis in Prefrontal Cortex of Rats

This study investigated the effects of quercetin on the alterations of serum elements in perimenopausal depression rat model induced by ovariectomy combined with chronic unpredictable mild stress (OVX-CUMS) and possible mechanisms. According to the results of the sucrose preference test, the rats were randomly assigned to four groups: sham, OVX-CUMS, OVX-CUMS + 17β-estradiol (17β-estradiol: 0.27 mg/kg.bw), and OVX-CUMS + Quercetin (Quercetin: 50 mg/kg.bw). At the end of experiment, serum and prefrontal cortex of rats were collected. The inductively coupled plasma mass spectrometry (ICP-MS) analysis showed that levels of calcium (Ca), magnesium (Mg), selenium (Se), cobalt (Co) and zinc (Zn) decreased, and levels of iron (Fe) and copper (Cu) increased in serum and prefrontal cortex of OVX-CUMS rats compared with sham group (p < 0.01). Meanwhile, the levels of the above elements in prefrontal cortex had correlation with behavioral characteristics in OVX-CUMS rats (p < 0.05 or p < 0.01). The abnormal elements in serum may cross blood-brain-barrier into the brain and induce oxidative stress, leading to ferroptosis. Furtherly, the expressions of ferroptosis-related protein including GPX4 and SLC7A11 were decreased in prefrontal cortex of OVX-CUMS rats (p < 0.01), which confirmed the above results. Quercetin treatment restored the above abnormal indicators (p < 0.05 or p < 0.01) induced by OVX-CUMS in rats. Our study suggested that quercetin regulated variation of elements in serum and prefrontal cortex, further inhibiting ferroptosis in prefrontal cortex through alleviating oxidative stress in OVX-CUMS rats.

Ethanolic and aqueous extracts of Lantana camara show antiepileptic and anxiolytic effects by inhibiting the ferroptosis pathway in kainate-treated mice

In Cameroon, epilepsy is one of the most common neurological diseases. Available anti-epileptic medication, on the other hand, have been associated with pharmacological toxicity and emotional impairment. The identification of a more efficient replacement is critical. Recent research reveals that ferroptosis contributes to the pathophysiology of epilepsy and related anxiety disorders. Lantana camara is a plant with a high neuropharmacological potential, but its mechanisms of action have yet to be understood. The purpose of this study was to determine the effect of ethanolic and aqueous extracts of Lantana camara on the kainate model of epilepsy in mice. The focus was on these extracts' capacity to suppress ferroptosis. Mice were injected with kainate (12 mg/kg, i.p.) to induce epilepsy. After status epilepticus, animals were left for 19 days, which correspond to an epileptogenic period. After the appearance of spontaneous recurrent seizures, mice were treated with distilled water (10 ml/kg, p.o.), levetiracetam (80 mg/kg, p.o.), sodium valproate (300 mg/kg, p.o.), ethanolic extract of L. camara (230, 460, 920 mg/kg, p.o.), or an aqueous extract of L. camara (460 mg/kg p.o.). These treatments lasted for 14 days. During this period, the number and duration of seizures were recorded. The mice were then subjected to elevated zero-maze and open field tests to assess anxiety-like behavior. At the end, mice were sacrificed and hippocampus, amygdala, and striatum were dissected out for biochemical and histological analyses. The extracts alleviated seizure- and anxiety-like behavior in KA-treated mice. Decreased iron levels, reflected by a decrease in ferritin levels and a increase in transferrin levels, were observed in the hippocampus, striatum and amygdala of the extract-treated group compared to the KA-treated group. In addition, increase in GABA and GSH levels, and a decrease in MDA levels were observed in these groups. Hematoxylin-eosin staining revealed less pronounced neuronal degeneration and a more sustained architecture in the brain region of extract-treated mice. These findings indicated that ethanolic and aqueous extracts of L. camara effectively attenuate seizures and anxiety disorders. Probable mechanisms of action include GABAergic, iron, GSH, and MDA modulations.

Uncovering the therapeutic efficacy and mechanisms of Quercetin on traumatic brain injury animals: a meta-analysis and network pharmacology analysis

Quercetin, a flavonoid and natural antioxidant derived from fruits and vegetables, has shown promising results in the improvement of traumatic brain injury (TBI). This study aims to elucidate the therapeutic role and potential mechanisms of quercetin in TBI through systematic evaluations and network pharmacology approaches. First, the meta-analysis was conducted via Review Manager 5.4 software. The meta-analysis results confirmed that quercetin could improve TBI, primarily by inhibiting inflammation, oxidative stress, and apoptosis. Subsequently, targets related to quercetin and those related to TBI were extracted from drug-related databases and disease-related databases, respectively. We found that the potential mechanism by which quercetin treats TBI is largely associated with ferroptosis, as indicated by functional analysis. Based on this, we identified 29 ferroptosis-related genes (FRGs) associated with quercetin and TBI, and then performed Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis using the DAVID database. The functional enrichment results revealed that these FRGs mainly involve the HIF-1 signaling pathway, IL-17 signaling pathway, and PI3K-Akt signaling pathway. Subsequently, we constructed a PPI network and identified the top 10 targets-HIF1A, IL6, JUN, TP53, IL1B, PTGS2, PPARG, EGFR, IFNG, and GSK3B-as hub targets. Meanwhile, molecular docking results further demonstrated that quercetin could stably bind to the top 10 hub targets. In conclusion, the above results elucidated that quercetin could effectively attenuates TBI by inhibiting inflammation, oxidative stress, and apoptosis. Notably, quercetin may also target these hub targets to regulate ferroptosis and improve TBI.

Green Onion-Derived Exosome-like Nanoparticles Prevent Ferroptotic Cell Death Triggered by Glutamate: Implication for GPX4 Expression

In recent years, alongside research on mammalian-derived exosomes, there has been increasing interest in the physiological activities of plant-derived exosome-like nanoparticles (PDEN). The biocompatibility, minimal side effects, and diverse bioactive ingredients contained in PDEN make them valuable as potential therapeutic agents for an extensive range of diseases. In this study, we cost-effectively isolated exosome-like nanoparticles from green onion (Allium fistulosum) using polyethylene glycol and examined their biological activity in HT-22 cells exposed to glutamate. The isolated green onion-derived exosome-like nanoparticle (GDEN) had an average diameter of 167.4 nm and a zeta potential of -16.06 mV. GDEN effectively inhibited glutamate-induced Ca2+ influx and lipid peroxidation, thereby preventing ferroptotic cell death in HT-22 mouse hippocampal cells. Additionally, GDEN reduced the intracellular iron accumulation by modulating the expression of proteins associated with iron metabolism, including transferrin receptor 1, ferroportin 1, divalent metal transporter 1, and ferritin. Notably, GDEN upregulated the expression of glutathione peroxidase 4, a potent antioxidant protein involved in ferroptosis, along with an increase in glutathione synthesis. These findings indicate that GDENs have the potential to serve as bioactives from natural sources against glutamate-induced neuronal cell death, like ferroptosis. This study advances the investigation into the potential medical applications of GDEN and may provide a new approach for the utilization of these bioactive components against neuronal disorders.

Framework Nucleic Acids Loaded with Quercetin: Protecting Retinal Neurovascular Unit via the Protein Kinase B/Heme Oxygenase-1 Pathway

Retinal neovascular disease is a leading cause of vision loss and blindness globally. It occurs when abnormal new blood vessels form in the retina. In this study, we utilized tetrahedral framework nucleic acids (tFNAs) as vehicles to load quercetin (QUE), a small-molecule flavonoid, forming a deoxyribonucleic acid (DNA) nanocomplex, tFNAs-QUE. Our data show this nanocomplex inhibits pathological neovascularization, reduces the area of retinal nonperfusion area, protects retinal neurons, and preserves the visual function. Further, we discovered that tFNAs-QUE selectively upregulates the AKT/Nrf2/HO-1 signaling pathway, which can suppress pathological vascular growth and exert antioxidative effects. Therefore, this study presents a promising small-molecule-loading mechanism for the treatment of ischemic retinal diseases.

Isoliensinine activated the Nrf2/GPX4 pathway to inhibit glutamate-induced ferroptosis in HT-22 cells

Isoliensinine (ISO), a natural compound, is a bibenzyl isoquinoline alkaloid monomer in lotus seed, which has strong antioxidant and free radical scavenging activities. The oxidative toxicity caused by glutamic acid overdose is one of the important mechanisms of nerve cell injury, and the oxidative toxicity caused by glutamic acid is related to ferroptosis. This study aims to establish a glutamate-induced injury model of mouse hippocampal neurons HT-22 cells, and investigate the protective effect of ISO on the neurotoxicity of glutamate-induced HT-22 cells. The results showed that ISO inhibited glutamate-induced ferroptosis of neuronal cells through nuclear factor E2-related factor 2/glutathione peroxidase 4 (Nrf2/GPX4) signaling pathway. Pretreatment of HT-22 cells with ISO significantly reduced glutamate-induced cell death. Ferroptosis inhibitors have the same effect. ISO inhibited the decrease of mitochondrial membrane potential detection and the increase of iron content induced by glutamate, the increase of malondialdehyde and reactive oxygen species in cytoplasm and lipid, and protected the activities of GPx and superoxide dismutase enzymes. In addition, WB showed that glutamic acid could induce the upregulated expression of long-chain esteryl coA synthase 4 (ACSL4) protein and the downregulated expression of SLC7A11 and GPX4 protein in HT-22 cells, while ISO could prevent the abnormal expression of these proteins induced by glutamic acid. The nuclear translocation of Nrf2 in HT-22 cells was increased, and the expression of downstream heme oxygenase-1 protein was upregulated. In summary, ISO protects HT-22 cells from glutamate-induced ferroptosis through a novel mechanism of the Nrf2/GPX4 signaling pathway.

Withaferin A protects against epilepsy by promoting LCN2-mediated astrocyte polarization to stopping neuronal ferroptosis

BACKGROUND

Epilepsy is among the most frequent severe brain diseases, with few treatment options available. Neuronal ferroptosis is an important pathogenic mechanism in epilepsy. As a result, addressing ferroptosis appears to be a promising treatment approach for epilepsy. Withaferin A (WFA) is a C28 steroidal lactone that has a broad range of neuroprotective properties. Nonetheless, the antiepileptic action of WFA and the intrinsic mechanism by which it inhibits ferroptosis following epilepsy remain unknown.

PURPOSE

This study aimed at investigating to the antiepileptic potential of WFA in epilepsy, as well as to propose a potential therapeutic approach for epilepsy therapy.

METHODS

We conducted extensive research to examine the impacts of WFA on epilepsy and ferroptosis, using the kainic acid (KA)-treated primary astrocyte as an in vitro model and KA-induced temporal lobe epilepsy mice as an in vivo model. To analyze the neuroprotective effects of WFA on epileptic mice, electroencephalogram (EEG) recording, Nissl staining, and neurological function assessments such as the Morris water maze (MWM) test, Y-maze test, Elevated-plus maze (O-maze) test, and Open field test were used. Furthermore, the mechanism behind the neuroprotective effect of WFA in epilepsy was investigated using the transcriptomics analysis and verified on epileptic patient and epileptic mouse samples using Western blotting (WB) and immunofluorescence (IF) staining. In addition, WB, IF staining and specific antagonists/agonists were used to investigate astrocyte polarization and the regulatory signaling pathways involved. More critically, ferroptosis was assessed utilizing lipocalin-2 (LCN2) overexpression cell lines, siRNA knockdown, JC-1 staining, WB, IF staining, flow cytometry, electron microscopy (TEM), and ferroptosis-related GSH and MDA indicators.

RESULTS

In this study, we observed that WFA treatment reduced the number of recurrent seizures and time in seizure, and the loss of neurons in the hippocampal area in in epileptic mice, and even improved cognitive and anxiety impairment after epilepsy in a dose depend. Furthermore, WFA treatment was proven to enhance to the transformation of post-epileptic astrocytes from neurotoxic-type A1 to A2 astrocytes in both in vivo and in vitro experiments by inhibiting the phosphoinositide 3-kinase /AKT signaling pathway. At last, transcriptomics analysis in combination with functional experimental validation, it was discovered that WFA promoted astrocyte polarity transformation and then LCN2 in astrocytes, which inhibited neuronal ferroptosis to exert neuroprotective effects after epilepsy. In addition, we discovered significant astrocytic LCN2 expression in human TLE patient hippocampal samples.

CONCLUSIONS

Taken together, for the first, our findings suggest that WFA has neuroprotective benefits in epilepsy by modulating astrocyte polarization, and that LCN2 may be a novel potential target for the prevention and treatment of ferroptosis after epilepsy.

Lutein inhibits glutamate-induced apoptosis in HT22 cells via the Nrf2/HO-1 signaling pathway

INTRODUCTION

Excessive glutamate levels induce oxidative stress, resulting in neuronal damage, and cell death. While natural antioxidants show promise for neuroprotection, their effectiveness in the central nervous system (CNS) is limited by the blood -brain barrier. Lutein, a neuroprotective carotenoid, has gained attention for its ability to traverse this barrier and accumulate in various brain regions. This study aimed to elucidate the mechanisms underlying the protective effects of lutein against glutamateinduced cell death in HT22 cells.

METHODS

HT22 cells were treated with lutein (1.25-20 μM) for 24 hours. Cell viability, ROS levels, apoptosis, and mitochondrial membrane potential were assessed following lutein pretreatment and glutamate exposure. Protein expression of apoptotic markers was analyzed using Western blotting.

RESULTS

Lutein effectively attenuated glutamate-induced apoptosis due to its antioxidant properties. Additionally, lutein inhibited glutamate-induced mitochondrial-mediated apoptosis. We observed that lutein modulated the nuclear translocation of nuclear factor erythroid 2 -related factor 2 (Nrf2) and upregulated the expression of heme oxygenase-1 (HO-1). Inhibition of HO-1 by tin protoporphyrin (SnPP), a synthetic inhibitor, weakened the protective effect of lutein. Furthermore, we demonstrated that lutein prevented the aberrant activation of MAPKs induced by glutamate, including ERK1/2, p38, and JNK, thereby conferring oxidative protection.

DISCUSSION

Our study highlights the potent antioxidant properties of lutein, which effectively safeguards against glutamate-induced mitochondrial apoptotic cell death through the Nrf2/HO-1 signaling pathway and inhibition of MAPK activation. These findings demonstrate that lutein exerts a neuroprotective effect against glutamate-induced neuronal cell damage.

Quercetin Modulates Ferroptosis via the SIRT1/Nrf-2/HO-1 Pathway and Attenuates Cartilage Destruction in an Osteoarthritis Rat Model

Osteoarthritis (OA) is the most common joint disease, causing symptoms such as joint pain, swelling, and deformity, which severely affect patients' quality of life. Despite advances in medical treatment, OA management remains challenging, necessitating the development of safe and effective drugs. Quercetin (QUE), a natural flavonoid widely found in fruits and vegetables, shows promise due to its broad range of pharmacological effects, particularly in various degenerative diseases. However, its role in preventing OA progression and its underlying mechanisms remain unclear. In this study, we demonstrated that QUE has a protective effect against OA development both in vivo and in vitro, and we elucidated the underlying molecular mechanisms. In vitro, QUE inhibited the expression of IL-1β-induced chondrocyte matrix metalloproteinases (MMP3 and MMP13) and inflammatory mediators such as INOS and COX-2. It also promoted the expression of collagen II, thereby preventing the extracellular matrix (ECM). Mechanistically, QUE exerts its protective effect on chondrocytes by activating the SIRT1/Nrf-2/HO-1 and inhibiting chondrocyte ferroptosis. Similarly, in an OA rat model induced by anterior cruciate ligament transection (ACLT), QUE treatment improved articular cartilage damage, reduced joint pain, and normalized abnormal subchondral bone remodeling. QUE also reduced serum IL-1β, TNF-α, MMP3, CTX-II, and COMP, thereby slowing the progression of OA. QUE exerts chondroprotective effects by inhibiting chondrocyte oxidative damage and ferroptosis through the SIRT1/Nrf-2/HO-1 pathway, effectively alleviating OA progression in rats.

miR-30a-5p mediates ferroptosis of hippocampal neurons in chronic cerebral hypoperfusion-induced cognitive dysfunction by modulating the SIRT1/NRF2 pathway

OBJECTIVE

Chronic cerebral hypoperfusion (CCH) is a common cause of brain dysfunction. As a microRNA (also known as miRNAs or miRs), miR-30a-5p participates in neuronal damage and relates to ferroptosis. We explored the in vivo and in vitro effects and functional mechanism of miR-30a-5p in CCH-triggered cognitive impairment through the silent information regulator 1 (SIRT1)/nuclear factor erythroid 2-related factor 2 (NRF2) pathway.

METHODS

After 1 month of CCH modeling through bilateral common carotid artery stenosis, mice were injected with 2 μL antagomir (also known as anti-miRNAs) miR-30a-5p, with cognitive function evaluated by Morris water maze and novel object recognition tests. In vitro HT-22 cell oxygen glucose deprivation (OGD) model was established, followed by miR-30a-5p inhibitor and/or si-SIRT1 transfections, with Fe2+ concentration, malonaldehyde (MDA) and glutathione (GSH) contents, reactive oxygen species (ROS), miR-30a-5p and SIRT1 and glutathione peroxidase 4 (GPX4) protein levels, NRF2 nuclear translocation, and miR-30a-5p-SIRT1 targeting relationship assessed.

RESULTS

CCH-induced mice showed obvious cognitive impairment, up-regulated miR-30a-5p, and down-regulated SIRT1. Ferroptosis occurred in hippocampal neurons, manifested by elevated Fe2+ concentration and ROS and MDA levels, mitochondrial atrophy, and diminished GSH content. Antagomir miR-30a-5p or miR-30a-5p inhibitor promoted SIRT1 expression and NRF2 nuclear translocation, increased GPX4, cell viability and GSH content, and reduced Fe2+ concentration and ROS and MDA levels. miR-30a-5p negatively regulated SIRT1. In vitro, miR-30a-5p knockout increased NRF2 nuclear translocation by up-regulating SIRT1, inhibiting OGD-induced ferroptosis in HT-22 cells.

CONCLUSION

miR-30a-5p induces hippocampal neuronal ferroptosis and exacerbates post-CCH cognitive dysfunction by targeting SIRT1 and reducing NRF2 nuclear translocation.

Recent Advances in the Inhibition of Membrane Lipid Peroxidation by Food-Borne Plant Polyphenols via the Nrf2/GPx4 Pathway

Lipid peroxidation (LP) leads to changes in the fluidity and permeability of cell membranes, affecting normal cellular function and potentially triggering apoptosis or necrosis. This process is closely correlated with the onset of many diseases. Evidence suggests that the phenolic hydroxyl groups in food-borne plant polyphenols (FPPs) make them effective antioxidants capable of preventing diseases triggered by cell membrane LP. Proper dietary intake of FPPs can attenuate cellular oxidative stress, especially damage to cell membrane phospholipids, by activating the Nrf2/GPx4 pathway. Nuclear factor E2-related factor 2 (Nrf2) is an oxidative stress antagonist. The signaling pathway regulated by Nrf2 is a defense transduction pathway of the organism against external stimuli such as reactive oxygen species and exogenous chemicals. Glutathione peroxidase 4 (GPx4), under the regulation of Nrf2, is the only enzyme that reduces cell membrane lipid peroxides with specificity, thus playing a pivotal role in regulating cellular ferroptosis and counteracting oxidative stress. This study explored the Nrf2/GPx4 pathway mechanism, antioxidant activity of FPPs, and mechanism of LP. It also highlighted the bioprotective properties of FPPs against LP and its associated mechanisms, including (i) activation of the Nrf2/GPx4 pathway, with GPx4 potentially serving as a central target protein, (ii) regulation of antioxidant enzyme activities, leading to a reduction in the production of ROS and other peroxides, and (iii) antioxidant effects on LP and downstream phospholipid structure. In conclusion, FPPs play a crucial role as natural antioxidants in preventing LP. However, further in-depth analysis of FPPs coregulation of multiple signaling pathways is required, and the combined effects of these mechanisms need further evaluation in experimental models. Human trials could provide valuable insights into new directions for research and application.

Application of natural products in regulating ferroptosis in human diseases

BACKGROUND

Ferroptosis is a type of cell death caused by excessive iron-induced peroxidation. It has been found to be involved in a variety of diseases, and natural products can be used to target ferroptosis in treatments. Natural products are biologically active compounds extracted or synthesized from nature. It is an important resource for the discovery of skeletons with a high degree of structural diversity and a wide range of bioactivities, which can be developed directly or used as a starting point for the optimization of new drugs.

PURPOSE

In this review, we aim to discuss the interactions between natural products and ferroptosis in the treatment of human diseases.

METHODS

Literature was searched in Pubmed, Science Direct, and Web of Science databases for the 11-year period from 2012 to 2023 using the search terms "natural products", "ferroptosis", "human disease", "neurodegenerative disease", "cardiovascular disease", and "cancer".

RESULTS

In this research, the roles of natural products and ferroptosis were investigated. We suggest that natural products, such as terpenoids, flavonoids, polyphenols, alkaloids, and saponins, can be used in therapeutic applications for human diseases, as well as in ferroptosis. Additionally, the main mechanisms of ferroptosis were summarized and discussed. Furthermore, we propose that natural products can be utilized to enhance the sensitivity of cancer cells to ferroptosis, thus helping to overcome drug resistance and inhibit metastasis. Moreover, natural products have the potential to modulate the expression levels of ferroptosis-related factors. Finally, the future directions of this field were highlighted.

CONCLUSION

The potential of natural products which focus on ferroptosis to treat human illnesses, particularly cancer, is very encouraging for human wellbeing.

Synergistic Effect of Layered Double Hydroxides Nanodosage Form to Induce Apoptosis and Ferroptosis in Breast Cancer

Background

Breast cancer is the most common cancer in women and one of the leading causes of cancer death worldwide. Ferroptosis, a promising mechanism of killing cancer cells, has become a research hotspot in cancer therapy. Simvastatin (SIM), as a potential new anti-breast cancer drug, has been shown to cause ferroptosis of cancer cells and inhibit breast cancer metastasis and recurrence. The purpose of this study is to develop a novel strategy boosting ferroptotic cascade for synergistic cancer therapy.

Methods

In this paper, iron base form of layered double hydroxide supported simvastatin (LDHs-SIM) was synthesized by hydrothermal co-precipitation method. The characterization of LDHs-SIM were assessed by various analytical techniques, including ultraviolet-visible (UV-vis) spectroscopy, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and transmission electron microscopy (TEM). Biological activity, ferroptosis mechanism and biocompatibility were analyzed through in vivo and in vitro analysis, so as to evaluate its therapeutic effect on breast cancer.

Results

The constructed LDHs-SIM nanosystem can not only release SIM through mevalonate (MVA) pathway, inhibit the expression of glutathione peroxidase 4 (GPX4), inhibit the expression of SLC7A11 and reduce the synthesis efficiency of GSH, but also promote the accumulation of Fe2+ in cells through the release of Fe3+, and increase the intracellular ROS content. In addition, LDHs-SIM nanosystem can induce apoptosis of breast cancer cells to a certain extent, and achieve the synergistic effect of apoptosis and ferroptosis.

Conclusion

In the present study, we demonstrated that nanoparticles of layered double hydroxides (LDHs) loaded with simvastatin were more effective than a free drug at inhibiting breast cancer cell growth, In addition, superior anticancer therapeutic effects were achieved with little systemic toxicity, indicating that LDHs-SIM could serve as a safe and high-performance platform for ferroptosis-apoptosis combined anticancer therapy.

Icariin‑curcumol promotes ferroptosis in prostate cancer cells through Nrf2/HO‑1 signaling

Ferroptosis is a form of regulatory cell death that relies on iron and reactive oxygen species (ROS) to inhibit tumors. The present study aimed to investigate whether icariin-curcumol could be a novel ferroptosis inducer in tumor inhibition. Various concentrations of icariin-curcumol were used to stimulate prostate cell lines (RWPE-2, PC-3, VCAP and DU145). Small interfering negative control (si-NC) and si-nuclear factor erythroid 2-related factor 2 (Nrf2) were used to transfect DU145 cells. Cell viability was determined by using cell counting kit-8. Ferroptosis-related factor levels were analyzed using western blotting and reverse transcription-quantitative PCR. Enzyme-linked immunosorbent assays were used to assess the ferrous (Fe2+), glutathione and malondialdehyde (MDA) content. The ROS fluorescence intensity was assessed using flow cytometry. DU145 cells were most sensitive to icariin-curcumol concentration. The Fe2+ content, ROS fluorescence intensity and MDA level gradually increased, while solute carrier family 7 member 11 (SLC7A11) level, glutathione peroxidase 4 (GPX4) level, GSH content, Nrf2 and heme oxygenase-1 (HO-1) decreased with icariin-curcumol in a dose-dependent manner. After si-Nrf2 was transfected, the cell proliferation ability, SLC7A11 and GPX4 levels declined compared with the si-NC group. In contrast to the control group, the icariin + curcumol group showed reductions in Nrf2 and HO-1 levels, cell proliferation, SLC7A11 and GPX4 levels, with an increase in Fe2+ content and ROS fluorescence intensity. Overexpression of Nrf2 reversed the regulation observed in the icariin + curcumol group. Icariin-curcumol induced ferroptosis in PCa cells, mechanistically by inhibiting the Nrf2/HO-1 signaling pathway. Icariin-curcumol could be used as a new type of ferroptosis inducer to treat PCa effectively.

Navigating neurological disorders: harnessing the power of natural compounds for innovative therapeutic breakthroughs

Novel treatments are needed as neurological issues become more frequent worldwide. According to the report, plants, oceans, microorganisms, and animals contain interesting drug discovery compounds. Alzheimer's, Parkinson's, and stroke reviews emphasize neurological disorders' complexity and natural substances' safety. Learn about marine-derived and herbal substances' neuroprotective characteristics and applications. Molecular pathways show these substances' neurological healing effects. This article discusses clinical usage of Bryostatin-1, Fucoidan, Icariin, Salvianolic acid, Curcumin, Resveratrol, etc. Their potential benefits for asthma and Alzheimer's disease are complex. Although limited, the study promotes rigorous scientific research and collaboration between traditional and alternative medical practitioners. Unexplored natural compounds, quality control, well-structured clinical trials, and interdisciplinary collaboration should guide future study. Developing and employing natural chemicals to treat neurological illnesses requires ethical sourcing, sustainability, and public awareness. This detailed analysis covers natural chemicals' current state, challenges, and opportunities in neurological disorder treatment. See also the graphical abstract(Fig. 1).

The effect of ferroptosis-related mitochondrial dysfunction in the development of temporal lobe epilepsy

Temporal lobe epilepsy (TLE) is the most common form of epileptic syndrome. It has been established that due to its complex pathogenesis, a considerable proportion of TLE patients often progress to drug-resistant epilepsy. Ferroptosis has emerged as an important neuronal death mechanism in TLE, which is primarily influenced by lipid accumulation and oxidative stress. In previous studies of ferroptosis, more attention has been focused on the impact of changes in the levels of proteins related to the redox equilibrium and signaling pathways on epileptic seizures. However, it is worth noting that the oxidative-reduction changes in different organelles may have different pathophysiological significance in the process of ferroptosis-related diseases. Mitochondria, as a key organelle involved in ferroptosis, its structural damage and functional impairment can lead to energy metabolism disorders and disruption of the excitatory inhibitory balance, significantly increasing the susceptibility to epileptic seizures. Therefore, secondary mitochondrial dysfunction in the process of ferroptosis could play a crucial role in TLE pathogenesis. This review focuses on ferroptosis and mitochondria, discussing the pathogenic role of ferroptosis-related mitochondrial dysfunction in TLE, thus aiming to provide novel insights and potential implications of ferroptosis-related secondary mitochondrial dysfunction in epileptic seizures and to offer new insights for the precise exploration of ferroptosis-related therapeutic targets for TLE patients.

Quercetin: A promising therapy for diabetic encephalopathy through inhibition of hippocampal ferroptosis

BACKGROUND

The pathophysiology of diabetic encephalopathy (DE), a significant diabetes-related pathological complication of the central nervous system, is poorly understood. Ferroptosis is an iron-dependent regulated necrotic cell death process that mediates the development of neurodegenerative and diabetes-related lesions. Quercetin (QE) exerts anti-ferroptotic effects in various diseases. However, the roles of ferroptosis in DE and the potential anti-ferroptotic mechanisms of QE are unclear.

PURPOSE

This study aimed to investigate if quercetin can ameliorate DE by inhibiting ferroptosis and to elucidate the potential anti-ferroptotic mechanisms of QE, thus providing a new perspective on the pathogenesis and prevention of DE.

METHODS

The spontaneously type 2 diabetic Goto-Kakizak rats and high glucose (HG)-induced PC12 cells were used as animal and in vitro models, respectively. The Morris water maze test was performed to evaluate the cognition of rats. Pathological damage was examined using hematoxylin and eosin staining. Mitochondrial damage was assessed using transmission electron microscopy. Lipid peroxidation was evaluated by examining the levels of malondialdehyde, superoxide dismutase, and glutathione. Additionally, the contents of iron ions were quantified. Immunofluorescence and western blotting were carried out to poke the protein levels. Network pharmacology analysis was conducted to construct a protein-protein interaction network for the therapeutic targets of QE in DE. Additionally, molecular docking and cellular thermal shift assay was performed to examine the target of QE.

RESULTS

QE alleviated cognitive impairment, decreased lipid peroxidation and iron deposition in the hippocampus, and upregulated the Nrf2/HO-1 signaling pathway. HG-induced ferroptosis in PC12 cells resulted in decreased cell viability accompanied by lipid peroxidation and iron deposition. QE mitigated HG-induced ferroptosis by upregulating the Nrf2/HO-1 pathway, which was partially suppressed upon Nrf2 inhibition. Network pharmacology analysis further indicated that the Nrf2/HO-1 signaling pathway is a key target of QE. Molecular docking experiments revealed that QE binds to KEAP1 through four hydrogen bonds. Moreover, QE altered the thermostability of KEAP1.

CONCLUSION

These results indicated that QE inhibits ferroptosis in the hippocampal neurons by binding to KEAP1 and subsequently upregulating the Nrf2/HO-1 signaling pathway.

The Interplay between Ferroptosis and Neuroinflammation in Central Neurological Disorders

Central neurological disorders are significant contributors to morbidity, mortality, and long-term disability globally in modern society. These encompass neurodegenerative diseases, ischemic brain diseases, traumatic brain injury, epilepsy, depression, and more. The involved pathogenesis is notably intricate and diverse. Ferroptosis and neuroinflammation play pivotal roles in elucidating the causes of cognitive impairment stemming from these diseases. Given the concurrent occurrence of ferroptosis and neuroinflammation due to metabolic shifts such as iron and ROS, as well as their critical roles in central nervous disorders, the investigation into the co-regulatory mechanism of ferroptosis and neuroinflammation has emerged as a prominent area of research. This paper delves into the mechanisms of ferroptosis and neuroinflammation in central nervous disorders, along with their interrelationship. It specifically emphasizes the core molecules within the shared pathways governing ferroptosis and neuroinflammation, including SIRT1, Nrf2, NF-κB, Cox-2, iNOS/NO·, and how different immune cells and structures contribute to cognitive dysfunction through these mechanisms. Researchers' findings suggest that ferroptosis and neuroinflammation mutually promote each other and may represent key factors in the progression of central neurological disorders. A deeper comprehension of the common pathway between cellular ferroptosis and neuroinflammation holds promise for improving symptoms and prognosis related to central neurological disorders.

Effects of chronic low-level lead (Pb) exposure on cognitive function and hippocampal neuronal ferroptosis: An integrative approach using bioinformatics analysis, machine learning, and experimental validation

Lead (Pb), a pervasive and ancient toxic heavy metal, continues to pose significant neurological health risks, particularly in regions such as Southeast Asia. While previous research has primarily focused on the adverse effects of acute, high-level lead exposure on neurological systems, studies on the impacts of chronic, low-level exposure are less extensive, especially regarding the precise mechanisms linking ferroptosis - a novel type of neuron cell death - with cognitive impairment. This study aims to explore the potential effects of chronic low-level lead exposure on cognitive function and hippocampal neuronal ferroptosis. This research represents the first comprehensive investigation into the impact of chronic low-level lead exposure on hippocampal neuronal ferroptosis, spanning clinical settings, bioinformatic analyses, and experimental validation. Our findings reveal significant alterations in the expression of genes associated with iron metabolism and Nrf2-dependent ferroptosis following lead exposure, as evidenced by comparing gene expression in the peripheral blood of lead-acid battery workers and workers without lead exposure. Furthermore, our in vitro and in vivo experimental results strongly suggest that lead exposure may precipitate cognitive dysfunction and induce hippocampal neuronal ferroptosis. In conclusion, our study indicates that chronic low-level lead exposure may activate microglia, leading to the promotion of ferroptosis in hippocampal neurons.

Mitochondrial ferritin alleviates ferroptosis in a kainic acid-induced mouse epilepsy model by regulating iron homeostasis: Involvement of nuclear factor erythroid 2-related factor 2

BACKGROUND

Epilepsy is a widespread and chronic disease of the central nervous system caused by a variety of factors. Mitochondrial ferritin (FtMt) refers to ferritin located within the mitochondria that may protect neurons against oxidative stress by binding excess free iron ions in the cytoplasm. However, the potential role of FtMt in epilepsy remains unclear. We aimed to investigate whether FtMt and its related mechanisms can regulate epilepsy by modulating ferroptosis.

METHODS

Three weeks after injection of adeno-associated virus (AAV) in the skull of adult male C57BL/6 mice, kainic acid (KA) was injected into the hippocampus to induce seizures. Primary hippocampal neurons were transfected with siRNA using a glutamate-mediated epilepsy model. After specific treatments, Western blot analysis, immunofluorescence, EEG recording, transmission electron microscopy, iron staining, silver staining, and Nissl staining were performed.

RESULTS

At different time points after KA injection, the expression of FtMt protein in the hippocampus of mice showed varying degrees of increase. Knockdown of the FtMt gene by AAV resulted in an increase in intracellular free iron levels and a decrease in the function of iron transport-related proteins, promoting neuronal ferroptosis and exacerbating epileptic brain activity in the hippocampus of seizure mice. Additionally, increasing the expression level of FtMt protein was achieved by AAV-mediated upregulation of nuclear factor erythroid 2-related factor 2 (Nrf2) gene in the hippocampus of seizure mice.

CONCLUSIONS

In epilepsy, Nrf2 modulates ferroptosis by involving the expression of FtMt and may be a potential therapeutic mechanism of neuronal injury after epilepsy. Targeting this relevant process for treatment may be a therapeutic strategy to prevent epilepsy.

Quercetin induces ferroptosis in gastric cancer cells by targeting SLC1A5 and regulating the p-Camk2/p-DRP1 and NRF2/GPX4 Axes

Quercetin (Quer) is a natural flavonoid known for its inhibitory effects against various cancers. However, the mechanism by which Quer inhibits gastric cancer (GC) has not yet been fully elucidated. Ferroptosis, a mode of programmed cell death resulting from lipid peroxidation, is regulated by abnormalities in the antioxidant system and iron metabolism. Through flow cytometry and other detection methods, we found that Quer elevated lipid peroxidation levels in GC cells. Transmission electron microscopy confirmed an increase in ferroptosis in Quer-induced GC. We demonstrated that Quer inhibits SLC1A5 expression. Molecular docking revealed Quer's binding to SLC1A5 at SER-343, SER-345, ILE-423, and THR-460 residues. Using immunofluorescence and other experiments, we found that Quer altered the intracellular ROS levels, antioxidant system protein expression levels, and iron content. Mechanistically, Quer binds to SLC1A5, inhibiting the nuclear translocation of nuclear factor erythroid 2-related factor 2 (NRF2), resulting in decreased xCT/GPX4 expression. Quer/SLC1A5 signaling activated p-Camk2, leading to upregulated p-DRP1 and enhanced ROS release. Additionally, Quer increased the intracellular iron content by inhibiting SLC1A5. These three changes collectively led to ferroptosis in GC cells. In conclusion, Quer targets SLC1A5 in GC cells, inhibiting the NRF2/xCT pathway, activating the p-Camk2/p-DRP1 pathway, and accelerating iron deposition. Ultimately, Quer promotes ferroptosis in GC cells, inhibiting GC progression. Overall, our study reveals that Quer can potentially impede GC progression by targeting SLC1A5, offering novel therapeutic avenues through the modulation of ferroptosis and iron homeostasis.

Natural product-derived ferroptosis mediators

It has been 11 years since ferroptosis, a new mode of programmed cell death, was first proposed. Natural products are an important source of drug discovery. In the past five years, natural product-derived ferroptosis regulators have been discovered in an endless stream. Herein, 178 natural products discovered so far to trigger or resist ferroptosis are classified into 6 structural classes based on skeleton type, and the mechanisms of action that have been reported are elaborated upon. If pharmacodynamic data are sufficient, the structure and bioactivity relationship is also presented. This review will provide medicinal chemists with some effective ferroptosis regulators, which will promote the research of natural product-based treatment of ferroptosis-related diseases in the future.

Analysis of the role of PANoptosis in seizures via integrated bioinformatics analysis and experimental validation

Background

Epilepsy is recognized as the most common chronic neurological condition among children, and hippocampal neuronal cell death has been identified as a crucial factor in the pathophysiological processes underlying seizures. In recent studies, PANoptosis, a newly characterized form of cell death, has emerged as a significant contributor to the development of various neurological disorders, including Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis. PANoptosis involves the simultaneous activation of pyroptosis, apoptosis, and necroptosis within the same population of cells. However, its specific role in the context of seizures remains to be fully elucidated. Further investigation is required to uncover the precise involvement of PANoptosis in the pathogenesis of seizures and to better understand its potential implications for the development of targeted therapeutic approaches in epilepsy.

Methods

In this study, the gene expression data of the hippocampus following the administration of kainic acid (KA) or NaCl was obtained from the Gene Expression Omnibus (GEO) database. The PANoptosis-related gene set was compiled from the GeneCards database and previous literature. Time series analysis was performed to analyze the temporal expression patterns of the PANoptosis-related genes. Gene set variation analysis (GSVA), Gene ontology (GO), and Kyoto encyclopedia of genes and genomes (KEGG) were employed to explore potential biological mechanisms underlying PANoptosis and its role in seizures. Weighted gene co-expression network analysis (WGCNA) and differential expression analysis were utilized to identify pivotal gene modules and PANoptosis-related genes associated with the pathophysiological processes underlying seizures. To validate the expression of PANoptosis-related genes, Western blotting or quantitative real-time polymerase chain reaction (qRT-PCR) assays were conducted. These experimental validations were performed in human blood samples, animal models, and cell models to verify the expression patterns of the PANoptosis-related genes and their relevance to epilepsy.

Results

The GSVA analysis performed in this study demonstrated that PANoptosis-related genes have the potential to distinguish between the control group and KA-induced epileptic mice. This suggests that the expression patterns of these genes are significantly altered in response to KA-induced epilepsy. Furthermore, the Weighted gene co-expression network analysis (WGCNA) identified the blue module as being highly associated with epileptic phenotypes. This module consists of genes that exhibit correlated expression patterns specifically related to epilepsy. Within the blue module, 10 genes were further identified as biomarker genes for epilepsy. These genes include MLKL, IRF1, RIPK1, GSDMD, CASP1, CASP8, ZBP1, CASP6, PYCARD, and IL18. These genes likely play critical roles in the pathophysiology of epilepsy and could serve as potential biomarkers for diagnosing or monitoring the condition.

Conclusion

In conclusion, our study suggests that the hippocampal neuronal cell death in epilepsy may be closely related to PANoptosis, a novel form of cell death, which provides insights into the underlying pathophysiological processes of epilepsy and helps the development of novel therapeutic approaches for epilepsy.

Induction of ferroptosis in human keratinocyte HaCaT cells by squalene hydroperoxide: Possible prevention of skin ferroptosis by botanical extracts

Ever since the proposal of ferroptosis, it has been studied as a nonapoptotic cell death caused by iron ion-dependent phospholipid (PL) peroxidation. We previously showed that treatment of human hepatoma cell line HepG2 with prepared PL hydroperoxide (PLOOH) resulted in ferroptosis. However, in human sebum, the major hydroperoxide is not PLOOH but squalene hydroperoxide (SQOOH), and to our knowledge, it is not established yet whether SQOOH induces ferroptosis in the skin. In this study, we synthesized SQOOH and treated human keratinocyte HaCaT cells with SQOOH. The results showed that SQOOH induces ferroptosis in HaCaT cells in the same way that PLOOH causes ferroptosis in HepG2 cells. Some natural antioxidants (botanical extracts) could inhibit the ferroptosis in both the cell types. Consequently, future research focus would revolve around the involvement of SQOOH-induced ferroptosis in skin pathologies as well as the prevention and treatment of skin diseases through inhibition of ferroptosis by botanical extracts.

PM2.5 exposure exacerbates seizure symptoms and cognitive dysfunction by disrupting iron metabolism and the Nrf2-mediated ferroptosis pathway

In recent years, air pollution has garnered global attention due to its ability to traverse borders and regions, thereby impacting areas far removed from the emission sources. While prior studies predominantly focused on the deleterious effects of PM2.5 on the respiratory and cardiovascular systems, emerging evidence has highlighted the potential risks of PM2.5 exposure to the central nervous system. Nonetheless, research elucidating the potential influences of PM2.5 exposure on seizures, specifically in relation to neuronal ferroptosis, remains limited. In this study, we investigated the potential effects of PM2.5 exposure on seizure symptoms and seizures-induced hippocampal neuronal ferroptosis. Our findings suggest that seizure patients residing in regions with high PM2.5 levels are more likely to disturb iron homeostasis and the Nrf2 dependent ferroptosis pathway compared to those living in areas with lower PM2.5 levels. The Morris Water Maze test, Racine scores, and EEG recordings in epileptic mice suggest that PM2.5 exposure can exacerbate seizure symptoms and cognitive dysfunction. Neurotoxic effects of PM2.5 exposure were demonstrated via Nissl staining and CCK-8 assays. Direct evidence of PM2.5-induced hippocampal neuronal ferroptosis was provided through TEM images. Additionally, increased Fe2+ and lipid ROS levels indirectly supported the notion of PM2.5-induced hippocampal ferroptosis. Therefore, our study underscores the necessity of preventing and controlling PM2.5 levels, particularly for patients with seizures.

Systematic Pharmacology and Experimental Validation to Reveal the Alleviation of Astragalus membranaceus Regulating Ferroptosis in Osteoarthritis

Background

Astragalus membranaceus (AM) shows promise as a therapeutic agent for osteoarthritis (OA), a debilitating condition with high disability rates. OA exacerbation is linked to chondrocyte ferroptosis, yet the precise pharmacological mechanisms of AM remain unclear.

Methods

We validated AM's protective efficacy in an anterior cruciate ligament transection (ACLT) mouse model of OA. The Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP) database was utilized to identify AM's active components and their targets. FerrDb (a database for regulators and markers of ferroptosis and ferroptosis-disease associations) pinpointed ferroptosis-related targets, while GeneCards, Online Mendelian Inheritance in Man (OMIM), Pharmacogenomics Knowledgebase (PharmGKB), Therapeutic Target Database (TTD), and DrugBank sourced OA-related genes. Molecular docking analysis further validated these targets. Ultimately, the validation of the results was accomplished through in vitro experiments.

Results

AM exhibited anabolic effects and suppressed catabolism in OA chondrocytes. Network pharmacology identified 19 common genes, and molecular docking suggested quercetin, an AM constituent, interacts with key proteins like HO-1 and NRF2 to inhibit chondrocyte ferroptosis. In vitro experiments confirmed AM's ability to modulate the NRF2/HO-1 pathway via quercetin, mitigating chondrocyte ferroptosis.

Conclusion

This study elucidates how AM regulates chondrocyte ferroptosis, impacting OA progression, providing a theoretical basis and experimental support for AM's scientific application.

Quercetin attenuates cerebral ischemic injury by inhibiting ferroptosis via Nrf2/HO-1 signaling pathway

AIMS

Ischemic stroke is a severe cerebrovascular disease in which neuronal death continually occurs through multiple forms, including apoptosis, autophagy, pyroptosis and ferroptosis. Quercetin (QRC), as a natural flavonoid compound, has been reported to have pharmacological effects on ischemic injury accompanied by unclear anti-ferroptotic mechanisms. This study is designed to investigate the therapeutic effects of QRC against ferroptosis in ischemic stroke.

MATERIALS AND METHODS

In vivo, the model of MCAO rats were used to assess the protective effect of QRC on cerebral ischemic. Additionally, we constructed oxidative stressed and ferroptotic cell models to explore the effects and mechanisms of QRC on ferroptosis. The related proteins were analysed by western blotting, immunohistochemical and immunofluorescence techniques.

RESULTS

The experiments demonstrated that QRC improves neurological deficits, infarct volume, and pathological features in MCAO rats, also increased the viability of HT-22 cells exposed to H2O2 and erastin. These results, including MDA, SOD, GSH, ROS levels and iron accumulation, indicated that QRC suppresses the generation of lipid peroxides and may involve in the regulatory of ferroptosis. Both in vitro and in vivo, QRC was found to inhibit ferroptosis by up-regulating GPX4 and FTH1, as well as down-regulating ACSL4. Furthermore, we observed that QRC enhances the nuclear translocation of Nrf2 and activates the downstream antioxidative proteins. Importantly, the effect of QRC on ferroptosis can be reversed by the Nrf2 inhibitor ML385.

CONCLUSIONS

This study provides evidence that QRC has a neuroprotective effect by inhibiting ferroptosis, demonstrating the therapeutic potential for cerebral ischemic stroke.