Dox initiates ferroptosis by targeting key regulatory genes involved in iron metabolism and redox homeostasis. This theory is based on the fact that there's a significant restitution of iron stores following treatment by dexrazoxane, an FDA-approved drug for Dox-induced cardiotoxicity. Through coordinated regulation of uptake (via the transferrin receptor), storage (via ferritin), and export (via SLC40A1), intracellular iron is tightly controlled under physiological conditions (Zhang et al., 2024[91]). This balance is disrupted by Dox on several levels, deactivating iron regulatory proteins that control ferritin and transferrin receptor expression, causing the accumulation and steady increase of redox-active iron (Qin et al., 2021[57]). Dox and Fe³⁺ can combine to form a Dox-Fe³⁺ complex, which further gets converted into a Dox-Fe²⁺ complex. This complex further leads to the formation of highly reactive hydroxyl radicals or highly toxic iron-peroxo complexes, consequently disrupting the DNA. Additionally, Dox reduces MITOL, further decreasing mitochondrial GPX4 expression and increasing Chac1-dependent GSH breakdown (Kitakata et al., 2021[36]). This condition allows lipid peroxides to accumulate beyond a threshold level in the presence of abundant iron and ROS, leading to permanent membrane damage and the initiation of ferroptosis.

The intermediate stage of ferroptosis is characterised by the extent of lipid peroxidation and the activation of redox signalling that commits the cardiomyocytes to irreversible damage. Through the fenton reaction, elevated levels of labile Fe²⁺ catalyse the generation of hydroxyl radicals, which start lipid oxidation by removing hydrogen atoms from bis-allylic sites in PUFAs (Cui and Ye, 2026[14]). Dox and Fe³⁺ can combine to form a Dox-Fe³⁺ complex, which further gets converted into a Dox-Fe²⁺ complex. A superoxide radical O^2-, and then a hydroxyl radical (OH• ) is created when the Dox-Fe²⁺ complex combines with oxygen (Myers, 1998[50]). This stimulates a series of downstream events that lead to the build-up of lipid hydroperoxides. This process is further accelerated by enzymatic means, especially ACSL4, which selectively oxidizes PUFA-phospholipids and accelerates the ferroptosis process (Ding et al., 2023[16]). Cardiolipin and other PUFA-rich phospholipids are abundant in the heart and greatly increase vulnerability to this oxidative cascade (Zhang et al., 2025[88]).

Secondary reactive aldehydes, including malondialdehyde and 4-hydroxynonenal, are increased when cardiomyocytes are exposed to Dox (Luo et al., 1997[44]). These electrophilic molecules form covalent adducts with proteins, nucleic acids, and membrane constituents, resulting in extensive cellular damage.

Ferroptosis is considered a key mediator of late-stage chronic cardiomyopathy, driven by excessive accumulation of lipid hydroperoxides in PUFA-rich membranes. This causes the generation of highly reactive electrophilic molecules that surpass the cellular glutathione-GPX4 system's detoxification capacity and lead to membrane damage (Forcina and Dixon, 2019[24]). This involves degradation of membrane-bound proteins, ion gradient disruption, and loss of plasma membrane integrity (Forcina and Dixon, 2019[24]). The typical ferroptotic shape of mitochondria, which reflects severe oxidative damage, includes condensed structure, increased membrane density, and a lack of cristae (Otasevic et al., 2021[54]). In contrast to apoptosis, nuclear integrity is mostly maintained, but cellular function is permanently impaired, which in later stages results in membrane rupture resembling necrosis (Ai et al., 2024[1]). This gradually progresses to a stage where myocardial tissue is remodelled by fibrotic tissue, and eventually cardiac dysfunction (Sun et al., 2026[66]). In an effort to make up for this dysfunctionality, the normal cardiomyocytes undergo hypertrophic alterations, which are often functionally inefficient and even contribute to a vicious circle of cellular stress (Sun et al., 2026[66]). Over time, these structural and functional changes result in progressive cardiac dysfunction, which clinically manifests as ventricular dilation, reduced ejection fraction, and eventually heart failure (Arrigoni et al., 2025[3]). In this manner, ferroptosis bridges cardiomyocyte structural damage to its functional impairment by acting as a driver of cellular pathology rather than just a cell death mechanism (Figure 3(Fig. 3)).

Being involved in a number of physiological processes, iron is considered to be an essential cellular element (Silva and Faustino, 2015[63]). However, if the concentration of this element reaches a toxic level, such as in the case of iron overload, it can even lead to dysfunction of the body's major organs (Gordan et al., 2018[27]). Ferroptosis, due to increased iron accumulation, has been well studied in the context of cardiotoxicity (Xie et al., 2022[80]).

A central event in ferroptosis-mediated mitochondrial damage is the dysregulation of intracellular iron homeostasis (Tayal et al., 2025[70]). Dox disrupts iron metabolism by interfering with the expression of iron regulatory proteins and thus promoting the release of iron from intracellular storage complexes, such as ferritin (Bhadra et al., 2025[6]; Yang et al., 2019[82]). Dox inhibits iron uptake by regulating iron-regulatory proteins such as IRP1 and IRP2, which regulate the expression of the transferrin receptor and ferritin genes. As Dox generates ROS, there is iron accumulation, which affects the activity of IRPs and leads to the accumulation of iron within the cells (Bhadra et al., 2025[6]). This leads to an increase in the LIP, a highly reactive form of iron that can participate in redox reactions (Ru et al., 2024[61]).

Excess iron within mitochondria catalyzes the fenton reaction, resulting in the production of highly reactive hydroxyl radicals (Ru et al., 2024[61]; Yu et al., 2021[87]). These radicals are highly reactive and non-specific, leading to widespread oxidation of mitochondrial macromolecules. mtDNA lacks the guarding histones and has limited repair capacity, making it susceptible to oxidative damage (Hanna et al., 2019[30]). Simultaneously, iron-induced oxidation of mitochondrial proteins disrupts mitochondrial metabolic activity, whereas elevated lipid oxidation impairs mitochondrial membrane integrity. Consequently, these effects result in a disruption in redox homeostasis, progressing the cell toward ferroptotic cell death (Yang and Stockwell, 2016[83]).

PUFAs, which contain multiple double bonds in their chemical structure, are highly prone to peroxidation by free radicals. Lipid peroxidation of mitochondrial phospholipids containing PUFAs is marked by the accumulation of iron, which enhances the fenton reaction and produces more ROS (Stockwell et al., 2017[65]). Cardiolipin, strategically located in the inner mitochondrial membrane, plays a crucial role in maintaining the function of the ETC and the integrity of the mitochondrial membrane (Paradies et al., 2019[55]). Therefore, peroxidation of cardiolipin during ferroptosis results in disruption of the mitochondrial membrane's structural organization, leading to loss of membrane integrity and increased permeability (Bucarey et al., 2026[7]). Lipid peroxidation alters membrane fluidity, triggers the formation of lipid pores, and further exacerbates mitochondrial dysfunction, indicating that the accumulation of lipid peroxides is not merely a consequence but a driving force of ferroptotic cell death (Mortensen et al., 2023[48]).

The cellular defense against lipid peroxidation is primarily mediated by the glutathione (GSH)-dependent antioxidant system, with GPX4 serving as a key enzyme (W. Zhang et al., 2024[89]). Under typical conditions, the detoxification of lipid peroxides is supported by the GSH-GPX4 antioxidant pathway, thereby preserving mitochondrial integrity (Bucarey et al., 2026[7]). Ferroptosis, on the other hand, causes GSH depletion and GPX4 inactivation, leading to lipid peroxidation and worsening mitochondrial oxidative damage (Zhang et al., 2024[89]). GPX4 reduces lipid hydroperoxides to non-toxic lipid alcohols, thereby preventing membrane damage, while in Dox-treated cardiomyocytes, this protective system is severely compromised (Tadokoro et al., 2020[67]).

Dox induces depletion of intracellular GSH levels by increasing oxidative stress and impairing synthesis. Simultaneously, it inhibits GPX4 activity either directly or indirectly through oxidative modifications (Wu et al., 2024[78]). The loss of GPX4 function leads to the accumulation of lipid hydroperoxides, which propagate lipid oxidation. The impaired regulation of the GPX4 antioxidant system further amplifies oxidative damage and thus mitochondrial membrane destabilization (Figure 4(Fig. 4)) (Tadokoro et al., 2020[67]; Wu et al., 2024[78]). At the same time, Dox decreases the cellular ability to detoxify lipid hydroperoxides by reducing intracellular glutathione levels and impairing GPX4 (system Xc-/GPX4 axis), a critical inhibitor of ferroptosis (Doroshow et al., 1980[20]). Tadokoro and his team reported significant downregulation of the GSH/GSSG ratio in Dox-challenged cardiomyocytes (Tadokoro et al., 2020[67]).

ETC in the mitochondria is vital for cellular energy homeostasis (Nolfi-Donegan et al., 2020[52]). Dox interacts with ETC complexes, impairing electron transfer and increasing electron leakage, thereby enhancing ROS production and reducing oxidative phosphorylation efficiency (Huang et al., 2022[32]). Dox particularly localizes to the inner mitochondrial membrane through cardiolipin binding, and Dox undergoes redox cycling at complex I and III, which produces excess superoxide and leads to impaired electron flow through the ETC (Aryal and Rao, 2016[4]; Wallace et al., 2020[73]).

Increased mtROS generation by TCA cycle intermediates like succinate, malate, and fumarate accounts for the stimulation of mitochondrial glutaminolysis and precipitation of ferroptosis.

As a result, ATP production decreases, leading to an energy deficit in cardiac cells (Huang et al., 2022[32]). Given the high energy demand of cardiac tissue, this bioenergetic disturbance leads to functional changes, including impaired contractility and increased susceptibility to cell death (Wu et al., 2024[78]).

Distinct morphological alterations in mitochondria show characteristics of ferroptosis and provide important insights into its role in cardiotoxicity (Fang et al., 2023[21]). There is a significant shrinkage of mitochondria with an associated decrease in the number of cristae, representative of structural damage (Wu et al., 2024[78]). This structural damage disrupts the ETC, leading to functional impairment too (Fang et al., 2023[21]; Wu et al., 2024[78]).

Ferroptosis works in a coordinated manner with other programmed cell death mechanisms, with mitochondria as a central mediator (Wu et al., 2023[79]). The structural and functional damage to mitochondria causes the release of cytochrome c, which initiates the process of apoptosis (Lu et al., 2026[43]; Wu et al., 2023[79]). Recent studies have also proposed a significant crosstalk between apoptosis and ferroptosis through the proapoptotic molecule PUMA (p53 upregulated modulator of apoptosis). Ferroptotic agents like erastin have been demonstrated to trigger endoplasmic reticulum stress, which further activates the PERK-eIF2α-ATF4-CHOP pathway and upregulates the expression of PUMA, rendering the cell susceptible to apoptosis.

These cells interactively undergo apoptosis and ferroptosis, thus exhibiting microscopic features of both (Lu et al., 2026[43]; Qiu et al., 2025[58]).

Similarly, ferroptosis works hand in hand with autophagy, being extensively described in studies related to cardiovascular diseases (Hu et al., 2025[31]). This process of ferritinophagy is also observed in Dox-induced cardiotoxicity, where it is mediated by the binding of the cytosolic autophagy receptor NCOA4 to FTH1, promoting the degradation of ferritin and iron accumulation, leading to ferroptosis (Wu et al., 2024[78]).

Necrotic pathways, particularly those involving mitochondrial permeability transition, may also intersect with ferroptosis under conditions of severe oxidative stress, serving lipid peroxidation and loss of membrane integrity (Christidi and Brunham, 2021[13]; Lu et al., 2026[43]). Although there is no specific study showing interactions between ferroptosis and necrosis, the evidence shows ferroptosis leads to membrane damage, ROS production, and lipid accumulation, and these phenotypes are similar to necrosis (Christidi and Brunham, 2021[13]). These connections to ferroptosis as a distinct feature imply the need to analyze multiple cell death signaling pathways.

As discussed above, Dox-induced cardiotoxicity is associated with oxidative stress and disrupted iron homeostasis, which are closely associated with activation of ferroptosis (Wu et al., 2024[78]). In the initial phase, the quinone moiety of Dox is responsible for ROS production and its interaction with mitochondrial ETC components (Linders et al., 2024[42]). This leads to excessive production of hydrogen peroxide, superoxide anions, and disrupts antioxidant defence systems, and dox also affects systemic and intracellular iron homeostasis, also shown to interfere with iron regulatory proteins and promote the release of iron from intracellular stores such as ferritin, thereby increasing lipid peroxidation (Wu et al., 2024[78]). Additionally, Dox-iron complexes further augments redox cycle, facilitating Fenton reactions that produce highly reactive hydroxyl radicals, which are responsible for damaging lipid membranes (Vitale et al., 2024[72]). Excessive ROS production and iron dysregulation create an oxidative intracellular environment, a precondition for ferroptosis initiation (Linders et al., 2024[42]). The LIP may stimulate enzymes like lipoxygenases or polyhydroxylases that control lipid peroxidation and oxygen balance. Importantly, these early molecular events promote structural and functional damage in cardiomyocytes, indicating that ferroptosis-related processes are initiated at an early stage in the Dox-induced cardiotoxicity signaling pathway. (Linders et al., 2024[42]; Vitale et al., 2024[72]).

Ferroptosis in cardiotoxicity is context-dependent, as various factors such as duration of exposure, dose, and the metabolic state of cardiomyocytes significantly influence the timing and extent of ferroptosis (Bhadra et al., 2025[6]). The exact position of ferroptosis in Dox-induced cellular death is determined, whether the drug has been administered for an acute duration or for chronic use. Dox, when administered at high doses even for an acute duration, generates ROS. It has been discussed above that any imbalance in redox homeostasis will lead to peroxidation of membrane phospholipids and disruption in the antioxidant defense mechanisms, resulting in iron accumulation that directly triggers ferroptosis. This fact puts this process as an early driver of cell death. On the other hand, when Dox is administered for a longer duration, even at a low dose, the induced ferroptosis will act as an amplifier for a series of molecular events progressing to cell death (Wang et al., 2025[75]). This cellular fate is also dependent on the status of the endogenous antioxidant mechanism, which decides the susceptibility as well as the extent of ferroptosis-induced damage (Feng et al., 2023[23]). Here, the ferroptosis acts as an intermediate component that directs oxidative stress and iron accumulation towards permanent cell damage. It can be, therefore, stated that factors associated with clinical conditions will tell about the position of ferroptosis in the cell death cascade.

There are studies indicating that ferroptosis acts not merely as one of the regulated cell death mechanisms involved in Dox-induced cardiac cell death but rather as a primary driver that initiates the whole cardiotoxicity (Fang et al., 2023[21]). Agents such as ferrostatin-1 and liproxstatin-1, which specifically inhibit lipid peroxidation and ferroptotic cell death, have been demonstrated to ameliorate drug-induced cardiotoxicity in both in vitro and in vivo models (Cha et al., 2025[9]; Fang et al., 2023[21]; Yu et al., 2026[85]). These studies suggest that ferroptosis plays a causative role as an early event in cell death.

Ferroptosis-induced iron accumulation and lipid peroxidation may be considered as instigating episodes, but they are not the final facilitators of Dox-induced cardiac cell death. A hallmark of ferroptosis is a reduction in GSH levels, accompanied by the inactivation of GPX4, which is responsible for lipid peroxidation (Zhang et al., 2024[89]). The resultant accumulation of lipid peroxidation products, such as malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE), is typically observed before any notable signs of apoptosis or necrosis appear, supporting the early activation of ferroptotic pathways (Yan et al., 2021[81]). This finding is also corroborated by some genetic studies where overexpression of GPX4 or upregulation of system Xc⁻ (via SLC7A11) has been demonstrated to protect against Dox-induced cardiotoxicity (Zhang et al., 2024[91]). In this context, ferroptosis can be recognized as a key early determinant of cardiac cell death and a promising target for adjunct therapy with doxorubicin.

In contrast to the above evidence indicating early involvement of ferroptosis, other studies point to it as a downstream amplifier in the cell death signalling cascade. Dox-induced mitochondrial damage, including impaired oxidative phosphorylation and increased electron leakage, can independently generate ROS. Studies have shown an early ROS production and underlying mitochondrial dysfunction even before the upregulation of ferroptotic markers (Chen et al., 2024[10]). Moreover, classical markers of ferroptosis, such as lipid peroxidation and GPX4 depletion, are often seen after the progression of oxidative stress and mitochondrial damage. This sequence implies that ferroptosis may be secondary to initial cellular insults and may serve to exacerbate rather than initiate damage (Tang et al., 2021[68]).

In this context, ferroptosis can be viewed as a feed-forward mechanism that amplifies pre-existing oxidative and metabolic stress. Once triggered, ferroptotic processes further increase lipid peroxidation and ROS production, thereby accelerating cellular dysfunction and death. This perspective is consistent with the observation that ferroptosis inhibitors are often more effective when administered during later stages of injury, suggesting a role in limiting damage progression rather than preventing its initiation (Chen et al., 2024[10]; Tang et al., 2021[68]). These observations propose a concept of the ferroptotic vicious circle, where the cardiac cell damage triggers ferroptosis, which further amplifies the cardiac injury, ultimately leading to cardiac cell death.

The authors declare that they have no conflict of interest.

No funding was received.

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The authors used Grammarly software to improve the readability and language of the manuscript. After using this tool, the authors reviewed and edited the content as needed and take full responsibility for the content of the published article.

Yogender Goswami: Data Analysis, Writing the Draft, Original Draft Preparation; Nisha Sharma and Umashanker Navik: Writing - Reviewing and Editing, Supervision