Discovery of 2-vinyl-10H-phenothiazine derivatives as a class of ferroptosis inhibitors with minimal human Ether-a-go-go Related Gene (hERG) Activity for the treatment of DOX-induced cardiomyopathy

A novel integrated diagnostic and therapeutic ferroptosis inhibitor based on a phenothiazine scaffold with ROS-Responsive strategy

Ferroptosis is a newly discovered form of cell death that is closely related to the occurrence of various diseases, such as neurodegenerative diseases, cardiovascular and cerebrovascular ischemic damage, and organ fibrosis. Therefore, the discovery of new active compounds with ferroptosis inhibitory activity is regarded as a new strategy for the clinical treatment of these diseases. In this study, a multifunctional prodrug molecule PNX-B2 with a phenoxazine structure was designed based on the oxidative microenvironment characteristic of ferroptosis. PNX-B2 can recognize the ferroptosis-associated oxidative conditions and simultaneously release compounds with ferroptosis-inhibitory activity. Moreover, it integrates diagnostic and therapeutic functions and offers a fluorescent indication of the ferroptosis microenvironment. PNX-B2 has demonstrated excellent ferroptosis-inhibitory activity with an EC50 value of 1.7 nM. This intelligent multifunctional compound shows great potential as a novel clinical agent for ferroptosis inhibition and presents broad prospects for future development.

Natural flavonoids from herbs and nutraceuticals as ferroptosis inhibitors in central nervous system diseases: current preclinical evidence and future perspectives

Flavonoids are a class of important polyphenolic compounds, renowned for their antioxidant properties. However, recent studies have uncovered an additional function of these natural flavonoids: their ability to inhibit ferroptosis. Ferroptosis is a key mechanism driving cell death in central nervous system (CNS) diseases, including both acute injuries and chronic neurodegenerative disorders, characterized by iron overload-induced lipid peroxidation and dysfunction of the antioxidant defense system. This review discusses the therapeutic potential of natural flavonoids from herbs and nutraceuticals as ferroptosis inhibitors in CNS diseases, focusing on their molecular mechanisms, summarizing findings from preclinical animal models, and providing insights for clinical translation. We specifically highlight natural flavonoids such as Baicalin, Baicalein, Chrysin, Vitexin, Galangin, Quercetin, Isoquercetin, Eriodictyol, Proanthocyanidin, (-)-epigallocatechin-3-gallate, Dihydromyricetin, Soybean Isoflavones, Calycosin, Icariside II, and Safflower Yellow, which have shown promising results in animal models of acute CNS injuries, including ischemic stroke, cerebral ischemia-reperfusion injury, intracerebral hemorrhage, subarachnoid hemorrhage, traumatic brain injury, and spinal cord injury. Among these, Baicalin and its precursor Baicalein stand out due to extensive research and favorable outcomes in acute injury models. Mechanistically, these flavonoids not only regulate the Nrf2/ARE pathway and activate GPX4/GSH-related antioxidant pathways but also modulate iron metabolism proteins, thereby alleviating iron overload and inhibiting ferroptosis. While flavonoids show promise as ferroptosis inhibitors for CNS diseases, especially in acute injury settings, further studies are needed to evaluate their efficacy, safety, pharmacokinetics, and blood-brain barrier penetration for clinical application.

Advances in Ferroptosis Research: A Comprehensive Review of Mechanism Exploration, Drug Development, and Disease Treatment

In recent years, ferroptosis, as an emerging modality of programmed cell death, has captured significant attention within the scientific community. This comprehensive review meticulously canvasses the pertinent literature of the past few years, spanning multiple facets. It delves into the intricate mechanisms underpinning ferroptosis, tracks the evolution of its inducers and inhibitors, and dissects its roles in a diverse array of diseases, as well as the resultant therapeutic implications. A profound exploration is conducted of the functional mechanisms of ferroptosis-related molecules, intracellular pathways, metabolic cascades, and signaling transduction routes. Novel ferroptosis inducers and inhibitors are introduced in detail, covering their design blueprints, synthetic methodologies, and bioactivity profiles. Moreover, an exhaustive account is provided regarding the involvement of ferroptosis in malignancies, neurodegenerative disorders, cardiovascular ailments, and other pathologies. By highlighting the pivotal status and potential therapeutic regimens of ferroptosis in various diseases, this review aspires to furnish a thorough and profound reference framework for future investigations and clinical translations in the ferroptosis domain.

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.

Ferroptosis in Cardiovascular Diseases and Ferroptosis-Related Intervention Approaches

OBJECTIVE

Cardiovascular diseases (CVDs) are major public health problems that threaten the lives and health of individuals. The article has reviewed recent progresses about ferroptosis and ferroptosis-related intervention approaches for the treatment of CVDs and provided more references and strategies for targeting ferroptosis to prevent and treat CVDs.

METHODS

A comprehensive review was conducted using the literature researches.

RESULTS AND DISCUSSION

Many ferroptosis-targeted compounds and ferroptosis-related genes may be prospective targets for treating CVDs and our review provides a solid foundation for further studies about the detailed pathological mechanisms of CVDs.

CONCLUSION

There are challenges and limitations about the translation of ferroptosis-targeted potential therapies from experimental research to clinical practice. It warrants further exploration to pursure safer and more effective ferroptosis-targeted thereapeutic approaches for CVDs.

FerroLigandDB: A Ferroptosis Ligand Database of Structure-Activity Relations

Ferroptosis is an iron-dependent programmed cell death characterized by lipid peroxidation that is linked to the pathophysiological processes in many diseases, such as neurodegenerative diseases, cancers, ischemia-reperfusion injuries, and organ damages. Many proteins are associated with ferroptosis signal transduction pathways. Novel chemical compounds are demanded to explore and regulate these pathways. Therefore, a ferroptosis ligand database, which holds relations among chemical structures, targets, bioactivities, and diseases, is needed for discovering and designing new ferroptosis regulators. This work reports FerroLigandDB, a manually curated database for small-molecular ferroptosis regulators. The database comprises 466 ferroptosis inducer entries (with 380 unique molecular structures) and 539 ferroptosis inhibitor entries (with 468 unique molecular structures) (note: one compound can be recorded as multiple entries due to the different assays). Each ferroptosis ligand entry is detailed with compound IDs, structure attributes, bioactivity values, test objects, target information, associated diseases, and references. The fields in the FerroLigandDB database implicitly contain relationships among chemical structures, bioactivities, targets, and diseases. Thus, FerroLigandDB is a comprehensive resource for scientists to design and discover novel ferroptosis regulators. The user interface of FerroLigandDB is implemented with query features and data visualization facilities. With compound identifiers, the compounds are linked to the records of other chemoinformatics databases (such as PubChem and SciFinder). The FerroLigandDB database is freely accessible at http://ferr.gulab.org.cn/.

Design and synthesis of sulfonamide phenothiazine derivatives as novel ferroptosis inhibitors and their therapeutic effects in spinal cord injury

Ferroptosis is a novel style of cell death, and studies have shown that ferroptosis is strongly associated with spinal cord injury (SCI). A large number of ferroptosis inhibitors have been reported, but so far no ferroptosis inhibitor has been used clinically. Therefore there is an urgent need to discover a better inhibitor of ferroptosis. In this study, 24 novel sulfonamide phenothiazine ferroptosis inhibitors were designed and synthesized, followed by structure-activity relationship studies on these compounds. Among them, compound 23b exhibited the best activity in Erastin-induced PC12 cells (EC50 = 0.001 μM) and demonstrated a low hERG inhibition activity (IC50 > 30 μM). Additionally, compound 23b was identified as a ROS scavenger and showed promising therapeutic effects in an SD rat model of SCI. Importantly, 23b did not display significant toxicity in both in vivo and in vitro experiments and show good pharmacokinetic properties. These findings suggest that compound 23b, a novel ferroptosis inhibitor, holds potential as a therapeutic agent for spinal cord injury and warrants further investigation.

Decoding ferroptosis: Revealing the hidden assassin behind cardiovascular diseases

The discovery of regulatory cell death processes has driven innovation in cardiovascular disease (CVD) therapeutic strategies. Over the past decade, ferroptosis, an iron-dependent form of regulated cell death driven by excessive lipid peroxidation, has been shown to drive the development of multiple CVDs. This review provides insights into the evolution of the concept of ferroptosis, the similarities and differences with traditional modes of programmed cell death (e.g., apoptosis, autophagy, and necrosis), as well as the core regulatory mechanisms of ferroptosis (including cystine/glutamate transporter blockade, imbalance of iron metabolism, and lipid peroxidation). In addition, it provides not only a detailed review of the role of ferroptosis and its therapeutic potential in widely studied CVDs such as coronary atherosclerotic heart disease, myocardial infarction, myocardial ischemia/reperfusion injury, heart failure, cardiomyopathy, and aortic aneurysm but also an overview of the phenomenon and therapeutic perspectives of ferroptosis in lesser-addressed CVDs such as cardiac valvulopathy, pulmonary hypertension, and sickle cell disease. This article aims to integrate this knowledge to provide a comprehensive view of ferroptosis in a wide range of CVDs and to drive innovation and progress in therapeutic strategies in this field.

Ferroptosis inhibitors: past, present and future

Ferroptosis is a non-apoptotic mode of programmed cell death characterized by iron dependence and lipid peroxidation. Since the ferroptosis was proposed, researchers have revealed the mechanisms of its formation and continue to explore effective inhibitors of ferroptosis in disease. Recent studies have shown a correlation between ferroptosis and the pathological mechanisms of neurodegenerative diseases, as well as diseases involving tissue or organ damage. Acting on ferroptosis-related targets may provide new strategies for the treatment of ferroptosis-mediated diseases. This article specifically describes the metabolic pathways of ferroptosis and summarizes the reported mechanisms of action of natural and synthetic small molecule inhibitors of ferroptosis and their efficacy in disease. The paper also describes ferroptosis treatments such as gene therapy, cell therapy, and nanotechnology, and summarises the challenges encountered in the clinical translation of ferroptosis inhibitors. Finally, the relationship between ferroptosis and other modes of cell death is discussed, hopefully paving the way for future drug design and discovery.

The molecular mechanisms and potential drug targets of ferroptosis in myocardial ischemia-reperfusion injury

Myocardial ischemia-reperfusion injury (MIRI), caused by the initial interruption and subsequent restoration of coronary artery blood, results in further damage to cardiac function, affecting the prognosis of patients with acute myocardial infarction. Ferroptosis is an iron-dependent, superoxide-driven, non-apoptotic form of regulated cell death that is involved in the pathogenesis of MIRI. Ferroptosis is characterized by the accumulation of lipid peroxides (LOOH) and redox disequilibrium. Free iron ions can induce lipid oxidative stress as a substrate of the Fenton reaction and lipoxygenase (LOX) and participate in the inactivation of a variety of lipid antioxidants including CoQ10 and GPX4, destroying the redox balance and causing cell death. The metabolism of amino acid, iron, and lipids, including associated pathways, is considered as a specific hallmark of ferroptosis. This review systematically summarizes the latest research progress on the mechanisms of ferroptosis and discusses and analyzes the therapeutic approaches targeting ferroptosis to alleviate MIRI.

Beyond ferrostatin-1: a comprehensive review of ferroptosis inhibitors

Ferroptosis is an iron-catalysed form of regulated cell death, which is critically dependent on phospholipid peroxidation of cellular membranes. Ferrostatin 1 was one of the first synthetic radical-trapping antioxidants (RTAs) reported to block ferroptosis and it is widely used as reference compound. Ferroptosis has been linked to multiple diseases and the use of its inhibitors could have therapeutic potential. Although, novel biochemical pathways provide insights for different pharmacological targets, the use of lipophilic RTAs to block ferroptosis remains superior. In this Review, we provide a comprehensive overview of the different classes of ferroptosis inhibitors, focusing on endogenous and synthetic RTAs. A thorough analysis of their chemical, pharmacokinetic, and pharmacological properties and potential for in vivo use is provided.

Iron accumulation and lipid peroxidation: implication of ferroptosis in diabetic cardiomyopathy

Diabetic cardiomyopathy (DC) is a serious heart disease caused by diabetes. It is unrelated to hypertension and coronary artery disease and can lead to heart insufficiency, heart failure and even death. Currently, the pathogenesis of DC is unclear, and clinical intervention is mainly symptomatic therapy and lacks effective intervention objectives. Iron overdose mediated cell death, also known as ferroptosis, is widely present in the physiological and pathological processes of diabetes and DC. Iron is a key trace element in the human body, regulating the metabolism of glucose and lipids, oxidative stress and inflammation, and other biological processes. Excessive iron accumulation can lead to the imbalance of the antioxidant system in DC and activate and aggravate pathological processes such as excessive autophagy and mitochondrial dysfunction, resulting in a chain reaction and accelerating myocardial and microvascular damage. In-depth understanding of the regulating mechanisms of iron metabolism and ferroptosis in cardiovascular vessels can help improve DC management. Therefore, in this review, we summarize the relationship between ferroptosis and the pathogenesis of DC, as well as potential intervention targets, and discuss and analyze the limitations and future development prospects of these targets.

Ferroptosis Inhibitors Suppress Prostaglandin Synthesis in Lipopolysaccharide-Stimulated Macrophages

Necrostatin-1 blocks ferroptosis via an unknown mechanism and necroptosis through inhibition of receptor-interacting protein kinase-1 (RIP1). We report that necrostatin-1 suppresses cyclooxygenase-2-dependent prostaglandin biosynthesis in lipopolysaccharide-treated RAW264.7 macrophages (IC₅₀ ∼ 100 μM). This activity is shared by necrostatin-1i (IC₅₀ ∼ 50 μM), which lacks RIP1 inhibitory activity, but not the RIP1 inhibitors necrostatin-1s or deschloronecrostatin-1s. Furthermore, we show that the potent ferroptosis inhibitors and related compounds ferrostatin-1, phenoxazine, phenothiazine, and 10-methylphenothiazine strongly inhibit cellular prostaglandin biosynthesis with IC₅₀'s in the range of 30 nM to 3.5 μM. None of the compounds inhibit lipopolysaccharide-mediated cyclooxygenase-2 protein induction. In the presence of activating hydroperoxides, the necrostatins and ferroptosis inhibitors range from low potency inhibition to stimulation of in vitro cyclooxygenase-2 activity; however, inhibitory potency is increased under conditions of low peroxide tone. The ferroptosis inhibitors are highly effective reducing substrates for cyclooxygenase-2's peroxidase activity, suggesting that they act by suppressing hydroperoxide-mediated activation of the cyclooxygenase active site. In contrast, for the necrostatins, cellular prostaglandin synthesis inhibition does not correlate with peroxidase-reducing activity but rather with the presence of a thiohydantoin substituent, which conveys the ability to reduce the endoperoxide intermediate prostaglandin H₂ to prostaglandin F_2α in vitro. This finding suggests that necrostatin-1 blocks cellular prostaglandin synthesis and ferroptosis via a redox mechanism distinct from action as a one-electron donor. The results indicate that a wide range of compounds derived from redox-active chemical scaffolds can block cellular prostaglandin biosynthesis.

Targeting ferroptosis as a promising therapeutic strategy to treat cardiomyopathy

Cardiomyopathies are a clinically heterogeneous group of cardiac diseases characterized by heart muscle damage, resulting in myocardium disorders, diminished cardiac function, heart failure, and even sudden cardiac death. The molecular mechanisms underlying the damage to cardiomyocytes remain unclear. Emerging studies have demonstrated that ferroptosis, an iron-dependent non-apoptotic regulated form of cell death characterized by iron dyshomeostasis and lipid peroxidation, contributes to the development of ischemic cardiomyopathy, diabetic cardiomyopathy, doxorubicin-induced cardiomyopathy, and septic cardiomyopathy. Numerous compounds have exerted potential therapeutic effects on cardiomyopathies by inhibiting ferroptosis. In this review, we summarize the core mechanism by which ferroptosis leads to the development of these cardiomyopathies. We emphasize the emerging types of therapeutic compounds that can inhibit ferroptosis and delineate their beneficial effects in treating cardiomyopathies. This review suggests that inhibiting ferroptosis pharmacologically may be a potential therapeutic strategy for cardiomyopathy treatment.