Protective effect of butin against ischemia/reperfusion-induced myocardial injury in diabetic mice: involvement of the AMPK/GSK-3β/Nrf2 signaling pathway

Role of Gut Microbial Metabolites in Ischemic and Non-Ischemic Heart Failure

The effect of the gut microbiota extends beyond their habitant place from the gastrointestinal tract to distant organs, including the cardiovascular system. Research interest in the relationship between the heart and the gut microbiota has recently been emerging. The gut microbiota secretes metabolites, including Trimethylamine N-oxide (TMAO), short-chain fatty acids (SCFAs), bile acids (BAs), indole propionic acid (IPA), hydrogen sulfide (H2S), and phenylacetylglutamine (PAGln). In this review, we explore the accumulating evidence on the role of these secreted microbiota metabolites in the pathophysiology of ischemic and non-ischemic heart failure (HF) by summarizing current knowledge from clinical studies and experimental models. Elevated TMAO contributes to non-ischemic HF through TGF-ß/Smad signaling-mediated myocardial hypertrophy and fibrosis, impairments of mitochondrial energy production, DNA methylation pattern change, and intracellular calcium transport. Also, high-level TMAO can promote ischemic HF via inflammation, histone methylation-mediated vascular fibrosis, platelet hyperactivity, and thrombosis, as well as cholesterol accumulation and the activation of MAPK signaling. Reduced SCFAs upregulate Egr-1 protein, T-cell myocardial infiltration, and HDAC 5 and 6 activities, leading to non-ischemic HF, while reactive oxygen species production and the hyperactivation of caveolin-ACE axis result in ischemic HF. An altered BAs level worsens contractility, opens mitochondrial permeability transition pores inducing apoptosis, and enhances cholesterol accumulation, eventually exacerbating ischemic and non-ischemic HF. IPA, through the inhibition of nicotinamide N-methyl transferase expression and increased nicotinamide, NAD+/NADH, and SIRT3 levels, can ameliorate non-ischemic HF; meanwhile, H2S by suppressing Nox4 expression and mitochondrial ROS production by stimulating the PI3K/AKT pathway can also protect against non-ischemic HF. Furthermore, PAGln can affect sarcomere shortening ability and myocyte contraction. This emerging field of research opens new avenues for HF therapies by restoring gut microbiota through dietary interventions, prebiotics, probiotics, or fecal microbiota transplantation and as such normalizing circulating levels of TMAO, SCFA, BAs, IPA, H2S, and PAGln.

Mechanisms and Therapeutic Strategies for Myocardial Ischemia-Reperfusion Injury in Diabetic States

In patients with myocardial infarction, one of the complications that may occur after revascularization is myocardial ischemia-reperfusion injury (IRI), characterized by a depleted myocardial oxygen supply and absence of blood flow recovery after reperfusion, leading to expansion of myocardial infarction, poor healing of myocardial infarction and reversal of left ventricular remodeling, and an increase in the risk for major adverse cardiovascular events such as heart failure, arrhythmia, and cardiac cell death. As a risk factor for cardiovascular disease, diabetes mellitus increases myocardial susceptibility to myocardial IRI through various mechanisms, increases acute myocardial infarction and myocardial IRI incidence, decreases myocardial responsiveness to protective strategies and efficacy of myocardial IRI protective methods, and increases diabetes mellitus mortality through myocardial infarction. This Review summarizes the mechanisms, existing therapeutic strategies, and potential therapeutic targets of myocardial IRI in diabetic states, which has very compelling clinical significance.

Rosemary officinalis extract mitigates potassium dichromate-induced testicular degeneration in male rats: Insights from the Nrf2 and its target genes signaling pathway

This study aimed to investigate the protective effects of Rosemary ethanol extract (ROEE) on testicular damage induced by potassium Dichromate (PDC) in male rats regarding the signaling pathway of Nrf2 and its target genes and proteins. A total of 28 male rats were divided into four groups: control, PDC only (15 mg/kg b.w. orally), PDC + low dose ROEE (220 mg/kg b.w.), and PDC + high dose ROEE (440 mg/kg b.w.). After 28 days of consecutive treatment, the rats were sacrificed for histological, immunohistochemistry, and biochemical analyses. The results revealed that the ROEE treatment up-regulated the Nrf2 and its target genes (NQO1, HO-1) mRNA expressions compared to the PDC group. correspondingly, the protein levels of GCLM, GSH, SOD, and catalase were significantly increased in the ROEE-treated animals compared to the PDC-treated animals. Furthermore, ROEE administration led to increased serum levels of testosterone (T4) and decreased levels of estrogen (E2) compared to the PDC group. Semen analysis and histopathology demonstrated that ROEE administration significantly improved spermatological impairment caused by PDC. The immunoexpression of cytoplasmic HSP-90 was reduced in the ROEE-treated groups, while the expression of androgen receptor (AR) was markedly improved. ROEE exhibited protective effects against PDC-induced testicular damage, likely due to its antioxidant properties. However, further investigation is required to elucidate the underlying mechanisms of action.

Adipokines and their potential impacts on susceptibility to myocardial ischemia/reperfusion injury in diabetes

Coronary artery disease has a high mortality rate and is a striking public health concern, affecting a substantial portion of the global population. On the early onset of myocardial ischemia, thrombolytic therapy and coronary revascularization could promptly restore the bloodstream and nutrient supply to the ischemic tissue, efficiently preserving less severely injured myocardium. However, the abrupt re-establishment of blood flow triggers the significant discharge of previously accumulated oxidative substances and inflammatory cytokines, leading to further harm referred to as ischemia/reperfusion (I/R) injury. Diabetes significantly raises the vulnerability of the heart to I/R injury due to disrupted glucose and lipid processing, impaired insulin sensitivity and metabolic signaling, and increased inflammatory responses. Numerous studies have indicated that adipokines are crucial in the etiology and pathogenesis of obesity, diabetes, hyperlipidemia, hypertension, and coronary artery disease. Adipokines such as adiponectin, adipsin, visfatin, chemerin, omentin, and apelin, which possess protective properties against inflammatory activity and insulin resistance, have been shown to confer myocardial protection in conditions such as atherosclerosis, myocardial hypertrophy, myocardial I/R injury, and diabetic complications. On the other hand, adipokines such as leptin and resistin, known for their pro-inflammatory characteristics, have been linked to elevated cardiac lipid deposition, insulin resistance, and fibrosis. Meteorin-like (metrnl) exhibits opposite effects in various pathological conditions. However, the data on adipokines in myocardial I/R, especially in diabetes, is still incomplete and controversial. This review focuses on recent research regarding the categorization and function of adipokines in the heart muscle, and the identification of different signaling pathways involved in myocardial I/R injury under diabetic conditions, aiming to facilitate the exploration of therapeutic strategies against myocardial I/R injury in diabetes.

Investigating the Inhibitory Potential of Flavonoids against Aldose Reductase: Insights from Molecular Docking, Dynamics Simulations, and gmx_MMPBSA Analysis

Diabetes mellitus (DM) is a complex metabolic disorder characterized by chronic hyperglycemia, with aldose reductase playing a critical role in the pathophysiology of diabetic complications. This study aimed to investigate the efficacy of flavonoid compounds as potential aldose reductase inhibitors using a combination of molecular docking and molecular dynamics (MD) simulations. The three-dimensional structures of representative flavonoid compounds were obtained from PubChem, minimized, and docked against aldose reductase using Discovery Studio's CDocker module. The top 10 compounds Daidzein, Quercetin, Kaempferol, Butin, Genistein, Sterubin, Baicalein, Pulchellidin, Wogonin, and Biochanin_A were selected based on their lowest docking energy values for further analysis. Subsequent MD simulations over 100 ns revealed that Daidzein and Quercetin maintained the highest stability, forming multiple conventional hydrogen bonds and strong hydrophobic interactions, consistent with their favorable interaction energies and stable RMSD values. Comparative analysis of hydrogen bond interactions and RMSD profiles underscored the ligand stability. MMPBSA analysis further confirmed the significant binding affinities of Daidzein and Quercetin, highlighting their potential as aldose reductase inhibitors. This study highlights the potential of flavonoids as aldose reductase inhibitors, offering insights into their binding interactions and stability, which could contribute to developing novel therapeutics for DM complications.

Fighting ferroptosis: Protective effects of dexmedetomidine on vital organ injuries

Vital organ injury is one of the leading causes of global mortality and socio-economic burdens. Current treatments have limited efficacy, and new strategies are needed. Dexmedetomidine (DEX) is a highly selective α2-adrenergic receptor that protects multiple organs by reducing inflammation and preventing cell death. However, its exact mechanism is not yet fully understood. Understanding the underlying molecular mechanisms of its protective effects is crucial as it could provide a basis for designing highly targeted and more effective drugs. Ferroptosis is the primary mode of cell death during organ injury, and recent studies have shown that DEX can protect vital organs from this process. This review provides a detailed analysis of preclinical in vitro and in vivo studies and gains a better understanding of how DEX protects against vital organ injuries by inhibiting ferroptosis. Our findings suggest that DEX can potentially protect vital organs mainly by regulating iron metabolism and the antioxidant defense system. This is the first review that summarizes all evidence of ferroptosis's role in DEX's protective effects against vital organ injuries. Our work aims to provide new insights into organ therapy with DEX and accelerate its translation from the laboratory to clinical settings.

Mechanisms of mitophagy and oxidative stress in cerebral ischemia-reperfusion, vascular dementia, and Alzheimer's disease

Neurological diseases have consistently represented a significant challenge in both clinical treatment and scientific research. As research has progressed, the significance of mitochondria in the pathogenesis and progression of neurological diseases has become increasingly prominent. Mitochondria serve not only as a source of energy, but also as regulators of cellular growth and death. Both oxidative stress and mitophagy are intimately associated with mitochondria, and there is mounting evidence that mitophagy and oxidative stress exert a pivotal regulatory influence on the pathogenesis of neurological diseases. In recent years, there has been a notable rise in the prevalence of cerebral ischemia/reperfusion injury (CI/RI), vascular dementia (VaD), and Alzheimer's disease (AD), which collectively represent a significant public health concern. Reduced levels of mitophagy have been observed in CI/RI, VaD and AD. The improvement of associated pathology has been demonstrated through the increase of mitophagy levels. CI/RI results in cerebral tissue ischemia and hypoxia, which causes oxidative stress, disruption of the blood-brain barrier (BBB) and damage to the cerebral vasculature. The BBB disruption and cerebral vascular injury may induce or exacerbate VaD to some extent. In addition, inadequate cerebral perfusion due to vascular injury or altered function may exacerbate the accumulation of amyloid β (Aβ) thereby contributing to or exacerbating AD pathology. Intravenous tissue plasminogen activator (tPA; alteplase) and endovascular thrombectomy are effective treatments for stroke. However, there is a narrow window of opportunity for the administration of tPA and thrombectomy, which results in a markedly elevated incidence of disability among patients with CI/RI. It is regrettable that there are currently no there are still no specific drugs for VaD and AD. Despite the availability of the U.S. Food and Drug Administration (FDA)-approved clinical first-line drugs for AD, including memantine, donepezil hydrochloride, and galantamine, these agents do not fundamentally block the pathological process of AD. In this paper, we undertake a review of the mechanisms of mitophagy and oxidative stress in neurological disorders, a summary of the clinical trials conducted in recent years, and a proposal for a new strategy for targeted treatment of neurological disorders based on both mitophagy and oxidative stress.

Effect of dapagliflozin on ferroptosis through the gut microbiota metabolite TMAO during myocardial ischemia-reperfusion injury in diabetes mellitus rats

Dapagliflozin (DAPA) demonstrates promise in the management of diabetic mellitus (DM) and cardiomyopathy. Trimethylamine N-oxide (TMAO) is synthesized by the gut microbiota through the metabolic conversion of choline and phosphatidylcholine. Ferroptosis may offer novel therapeutic avenues for the management of diabetes and myocardial ischemia-reperfusion injury (IRI). However, the precise mechanism underlying ferroptosis in cardiomyocytes and the specific role of TMAO generated by gut microbiota in the therapeutic approach for DM and myocardial IRI utilizing DAPA need to be further explored. Nine male SD rats with specific pathogen-free (SPF) status were randomly divided equally into the normal group, the DM + IRI (DIR) group, and the DAPA group. The diversity of the gut microbiota was analyzed using 16S rRNA gene sequencing. Additionally, the Wekell technique was employed to measure the levels of TMAO in the three groups. Application of network pharmacology to search for intersection targets of DAPA, DIR, and ferroptosis, and RT-PCR experimental verification. Ultimately, the overlapping targets that were acquired were subjected to molecular docking analysis with TMAO. The changes of Bacteroidetes and Firmicutes in the gut microbiota of DIR rats were most significantly affected by DAPA. Escherichia-Shigella and Prevotella_9 within the phylum Bacteroidetes could be identified as the primary effects of DAPA on DIR. Compared with the normal group, the TMAO content in the DIR group was significantly increased, while the TMAO content in the DAPA group was decreased compared to the DIR group. For the network pharmacology analysis, DAPA and DIR generated 43 intersecting target genes, and then further intersected with ferroptosis-related genes, resulting in 11 overlapping target genes. The mRNA expression of ALB, HMOX1, PPARG, CBS, LCN2, and PPARA decreased in the DIR group through reverse transcription polymerase chain reaction (RT-PCR) validation, while the opposite trend was observed in the DAPA group. The docking score between TMAO and DPP4 was - 5.44, and the MM-GBSA result of - 22.02 kcal/mol. It epitomizes the finest docking performance among all the target genes with the lowest score. DAPA could reduce the levels of metabolite TMAO produced by gut microbiota, thereby regulating related target genes to decrease ferroptosis in DIR cardiomyocytes.

Dietary Polyphenols: Review on Chemistry/Sources, Bioavailability/Metabolism, Antioxidant Effects, and Their Role in Disease Management

Polyphenols, as secondary metabolites ubiquitous in plant sources, have emerged as pivotal bioactive compounds with far-reaching implications for human health. Plant polyphenols exhibit direct or indirect associations with biomolecules capable of modulating diverse physiological pathways. Due to their inherent abundance and structural diversity, polyphenols have garnered substantial attention from both the scientific and clinical communities. The review begins by providing an in-depth analysis of the chemical intricacies of polyphenols, shedding light on their structural diversity and the implications of such diversity on their biological activities. Subsequently, an exploration of the dietary origins of polyphenols elucidates the natural plant-based sources that contribute to their global availability. The discussion extends to the bioavailability and metabolism of polyphenols within the human body, unraveling the complex journey from ingestion to systemic effects. A central focus of the review is dedicated to unravelling the antioxidant effects of polyphenols, highlighting their role in combating oxidative stress and associated health conditions. The comprehensive analysis encompasses their impact on diverse health concerns such as hypertension, allergies, aging, and chronic diseases like heart stroke and diabetes. Insights into the global beneficial effects of polyphenols further underscore their potential as preventive and therapeutic agents. This review article critically examines the multifaceted aspects of dietary polyphenols, encompassing their chemistry, dietary origins, bioavailability/metabolism dynamics, and profound antioxidant effects. The synthesis of information presented herein aims to provide a valuable resource for researchers, clinicians, and health enthusiasts, fostering a deeper understanding of the intricate relationship between polyphenols and human health.

Ferroptosis mechanisms and regulations in cardiovascular diseases in the past, present, and future

Cardiovascular diseases (CVDs) are the main diseases that endanger human health, and their risk factors contribute to high morbidity and a high rate of hospitalization. Cell death is the most important pathophysiology in CVDs. As one of the cell death mechanisms, ferroptosis is a new form of regulated cell death (RCD) that broadly participates in CVDs (such as myocardial infarction, heart transplantation, atherosclerosis, heart failure, ischaemia/reperfusion (I/R) injury, atrial fibrillation, cardiomyopathy (radiation-induced cardiomyopathy, diabetes cardiomyopathy, sepsis-induced cardiac injury, doxorubicin-induced cardiac injury, iron overload cardiomyopathy, and hypertrophic cardiomyopathy), and pulmonary arterial hypertension), involving in iron regulation, metabolic mechanism and lipid peroxidation. This article reviews recent research on the mechanism and regulation of ferroptosis and its relationship with the occurrence and treatment of CVDs, aiming to provide new ideas and treatment targets for the clinical diagnosis and treatment of CVDs by clarifying the latest progress in CVDs research.

Forensic significance of intracardiac expressions of Nrf2 in acute myocardial ischemia

When exposed to oxidative and electrophilic stress, a protective antioxidant response is initiated by nuclear factor erythroid 2-related factor 2 (Nrf2). However, the extent of its importance in the forensic diagnosis of acute ischemic heart diseases (AIHD), such as myocardial infarction (MI), remains uncertain. On the other hand, immunohistochemical analyses of fibronectin (FN) and the terminal complement complex (C5b-9) prove valuable in identifying myocardial ischemia that precedes necrosis during the postmortem diagnosis of sudden cardiac death (SCD). In this study, we investigated the immunohistochemical levels of Nrf2, FN, and C5b-9 in human cardiac samples to explore their forensic relevance for the identification of acute cardiac ischemia. Heart samples were obtained from 25 AIHD cases and 39 non-AIHD cases as controls. Nrf2 was localized in the nuclei of cardiomyocytes, while FN and C5b-9 were detected in the myocardial cytoplasm. The number of intranuclear Nrf2 positive signals in cardiomyocytes increased in AIHD cases compared to control cases. Additionally, the grading of positive portions of cardiac FN and C5b-9 in the myocardium was also significantly enhanced in AIHD, compared to controls. Collectively, these results indicate that the immunohistochemical investigation of Nrf2 combined with FN, and/or C5b-9 holds the potential for identifying early-stage myocardial ischemic lesions in cases of SCD.

Morin ameliorates myocardial injury in diabetic rats via modulation of inflammatory pathways

BACKGROUND

High blood glucose levels in diabetes lead to vascular inflammation which accelerates atherosclerosis. Herein, Morin was orally administered in male Wistar rats, at the dose of 40 mg/kg for 28 days, and on the 27th and 28th day, ISO was administered to designate groups at the dose of 85 mg/kg s.c., to induce myocardial infarction.

RESULTS

Free radical generation, including ROS, in diabetes following ISO administration, leads to the activation of both intrinsic and extrinsic pathways of apoptosis. Morin significantly (p ≤ 0.05) reduced oxidative stress (GSH, MDA, SOD), cardiac injury markers (CK-MB, LDH), inflammation (TNF, IL-6), and apoptosis (Bax, BCl2, Caspase-3). In addition, it also reduced insulin and blood glucose levels. Akt/eNOS, Nrf2/HO-1, MAPK signaling pathways, and Insulin signal transduction pathways were positively modulated by morin pre-treatment.

CONCLUSIONS

Morin attenuated oxidative stress and inflammation and also modified the activity of various molecular pathways to mitigate cardiomyocyte damage during ISO-induced MI in diabetic rats.

Serelaxin Protects H9c2 Cardiac Myoblasts against Hypoxia and Reoxygenation-Induced Damage through Activation of AMP Kinase/Sirtuin1: Further Insight into the Molecular Mechanisms of the Cardioprotection of This Hormone

Serelaxin (RLX), namely the human recombinant Relaxin-2 hormone, protects the heart from ischemia/reperfusion (I/R)-induced damage due to its anti-inflammatory, anti-apoptotic and antioxidant properties. RLX acts by binding to its specific RXFP1 receptor whereby it regulates multiple transduction pathways. In this in vitro study, we offer the first evidence for the involvement of the AMP kinase/Sirtuin1 (AMPK/SIRT1) pathway in the protection by RLX against hypoxia/reoxygenation (H/R)-induced damage in H9c2 cells. The treatment of the H/R-exposed cells with RLX (17 nmol L-1) enhanced SIRT1 expression and activity. The inhibition of SIRT1 signaling with EX527 (10 µmol L-1) reduced the beneficial effect of the hormone on mitochondrial efficiency and cell apoptosis. Moreover, RLX upregulated the AMPK pathway, as shown by the increase in the expression of phospho-AMPK-activated protein. Finally, AMPK pathway inhibition by Compound C (10 and 20 μmol L-1) abrogated the increase in SIRT1 expression induced by RLX, thus suggesting the involvement of the AMPK pathway in this effect of RLX. These results strengthen the concept that RLX exerts its cardioprotective effects against H/R-induced injury through multiple pathways which also include AMPK/SIRT1. These new findings support the use of RLX or RLX-derived molecules as a promising therapeutic for those diseases in which I/R and oxidative stress play a pathogenic role.

PM2.5 Exposure-Linked Mitochondrial Dysfunction Negates SB216763-Mediated Cardio-Protection against Myocardial Ischemia-Reperfusion Injury

GSK3β is a promising target for treating various disease conditions, including myocardial ischemia-reperfusion injury (IR). This study investigated the potential of GSK3β as a novel drug for managing IR in rats exposed to PM2.5 for 1 day and up to 21 days. Female Wistar rats were exposed to PM2.5 at a concentration of 250 µg/m3 for 3 h daily for either a single day or 21 days. After exposure, the isolated rat hearts underwent 30 min of ischemia followed by 60 min of reperfusion. GSK3β inhibition effectively reduced IR injury in rat hearts from animals exposed to PM2.5 for 1 day but not in those exposed for 21 days. PM2.5 exposure disrupted the redox balance in mitochondria and reduced the gene expression of antioxidants (glutaredoxin and peroxiredoxin) and NRF2, which protects against oxidative stress. PM2.5 also impaired mitochondrial bioenergetics, membrane potential, and quality control, leading to mitochondrial stress. Importantly, PM2.5 increased the translocation of GSK3β into mitochondria and compromised the overall mitochondrial function, particularly in the 21-day-exposed rat myocardium. The results indicate that extended exposure to PM2.5 leads to oxidative stress that disrupts mitochondrial function and diminishes the effectiveness of GSK3β inhibitors in offering cardio-protection through mitochondria.

Cyasterone ameliorates sepsis-related acute lung injury via AKT (Ser473)/GSK3β (Ser9)/Nrf2 pathway

BACKGROUND

Acute lung injury (ALI) is a severe disease that can lead to acute respiratory distress syndrome (ARDS), characterized by intractable hypoxemia, poor lung compliance, and respiratory failure, severely affecting patients' quality of life. The pathogenesis of ALI has not been fully elucidated yet, and sepsis is an important cause of ALI. Among the organ injuries caused by sepsis, the lungs are the earliest damaged ones. Radix cyathulae is reported to have analgesic, anti-inflammatory, and anti-aging effects. Cyasterone is extracted from Radix cyathulae. However, it is not known whether cyasterone has protective effects for ALI. This study aims to investigate the effect of cyasterone on sepsis-related ALI and its mechanism.

METHODS

We used the cecal ligation peferation (CLP) method to establish a mouse sepsis model, and cyasterone was given intraperitoneally on days 1-3 to observe its preventive effect on sepsis-related acute lung injury. Primary murine peritoneal macrophages were used to investigate the molecular mechanism of cyasterone in vitro.

RESULTS

Cyasterone pretreatment inhibits pro-inflammatory cytokine production, NLRP3 inflammasome activation, and oxidative stress in vivo and in vitro. In addition, cyasterone attenuates sepsis-induced ALI by activating nuclear factor erythroid2-related factor (Nrf2), which may be associated with AKT(Ser473)/GSK3β(Ser9) pathway activation.

CONCLUSIONS

Cyasterone defends against sepsis-induced ALI by inhibiting inflammatory responses and oxidative stress, which depends heavily on the upregulation of the Nrf2 pathway through phosphorylation of AKT(Ser473)/GSK3β(Ser9). These results suggest cyasterone may be a valuable drug candidate for preventing sepsis-related ALI.

Samarcandin protects against testicular ischemia/reperfusion injury in rats via activation of Nrf2/HO-1-mediated antioxidant responses

The purpose of this study was to evaluate the effectiveness of samarcandin (SMR) in preventing testicular injury caused by ischemia/reperfusion (I/R) in rats. Rats were divided into 4 groups at random: the sham group, the T/D control group (CONT), the T/D group receiving SMR treatment at 10 mg/kg (SMR-10), and the T/D group receiving SMR treatment at 20 mg/kg (SMR-20). When compared to the CONT group, SMR improved the oxidant/antioxidant balance by reducing malondialdehyde (MDA), nitric oxide (NOx), and increasing reduced glutathione (GSH), gluta-thione peroxide (GSH-Px), and superoxide dismutase (SOD). Moreover, SMR increased the levels of the steroid hormones' testosterone (TST), follicle-stimulating hormone (FSH), and luteinizing hormone (LH) in the blood as well as controlled the inflammatory mediators; interleukin-6 (IL6), tumor necrosis factor alpha (TNF-α), and nuclear factor κB (NF-κB). Nevertheless, SMR-treated animals showed a considerable downregulation of the apoptotic marker caspase-3. The T/D-induced histopathological changes were reduced and Proliferating Cell Nuclear Antigen (PCNA) protein expression was enhanced by SMR. These effects are associated with upregulation of testicular (Nuclear factor erythroid 2-related factor 2 (Nrf2), Heme oxygenase-1 (HO-1), and downregulation of NF-κB mRNA expression levels. These findings suggest that SMR may be able to prevent T/D-induced testis damage by mainly regulating the expression of Nrf2 and NF-B, which seems to mediate its promising antioxidant, anti-inflammatory and antiapoptotic effects seen in this study.

CaMKK2 alleviates myocardial ischemia/reperfusion injury by inhibiting oxidative stress and inflammation via the action on the AMPK-AKT-GSK-3β/Nrf2 signaling cascade

OBJECTIVE

Calcium/calmodulin-dependent protein kinase kinase 2 (CaMKK2) can regulate numerous biological processes and is implicated in diverse pathological processes. Yet its role in myocardial ischemia/reperfusion (MI/R) injury remains unknown. This project explored the possible functions and mechanisms of CaMKK2 in MI/R injury.

METHODS

A rat model of MI/R in vivo was established using the left anterior descending coronary artery ligation method. Rat cardiomyocytes were exposed to hypoxia/reoxygenation (H/R) in vitro to establish a cell model. Overexpression of CaMKK2 was achieved by infecting recombinant adeno-associated virus or adenovirus expressing CaMKK2. Real-time quantitative PCR, immunoblotting, TTC staining, TUNEL assay, ELISA, oxidative stress detection assays, flow cytometry, and CCK-8 assay were carried out.

RESULTS

A decline in CaMKK2 levels was induced by MI/R in vivo or H/R in vitro. Up-modulation of CaMKK2 in rats ameliorated the cardiac injury evoked by MI/R injury accompanied by suppression of cardiac apoptosis, oxidative stress, and proinflammatory response. Rat cardiomyocytes with CaMKK2 overexpression were also protected from H/R damage by inhibiting apoptosis, oxidative stress, and proinflammatory response. CaMKK2 overexpression led to increased phosphorylation of AMPK, AKT, and GSK-3β, and enhanced activation of Nrf2 under MI/R or H/R conditions. Inhibition of AMPK abolished CaMKK2-mediated Nrf2 activation and relevant cardioprotective effect. Restraint of Nrf2 also diminished CaMKK2-mediated relevant cardioprotective effect.

CONCLUSIONS

Up-regulation of CaMKK2 provides a therapeutic benefit in the rat model of MI/R injury by boosting the Nrf2 pathway through regulation of AMPK/AKT/GSK-3β, which suggests CaMKK2 as a new molecular target for the treatment of MI/R injury.

AdipoRon mitigates tau pathology and restores mitochondrial dynamics via AMPK-related pathway in a mouse model of Alzheimer's disease

BACKGROUND

Alzheimer's disease (AD) is a complicated and refractory neurodegenerative disease that is typically characterized by memory loss and multiple cognitive impairments. Multiple neuropathology including hyperphosphorylated tau formation and accumulation, dysregulated mitochondrial dynamics, and synaptic damage have been well implicated in the progression of AD. So far, there are few valid and effective therapeutic modalities for treatment. AdipoRon, a specific adiponectin (APN) receptor agonist, is reported to be associated with cognitive deficits improvement. In the present study, we attempt to explore the potential therapeutic effects of AdipoRon on tauopathy and related molecular mechanisms.

METHODS

In this study, P301S tau transgenic mice were used. The plasma level of APN was detected by ELISA. The level of APN receptors was qualified by western blot and immunofluorescence. 6-month-old mice were treated with AdipoRon or vehicle by oral administration daily for 4 months. The benefits of AdipoRon on tau hyperphosphorylation, mitochondrial dynamics, and synaptic function were detected by western blot, immunohistochemistry, immunofluorescence, Golgi staining and transmission electron microscopy. Morris water maze test and novel object recognition test were conducted to explore memory impairments.

RESULTS

Compared with wild-type mice, the expression of APN in plasma in 10-month-old P301S mice was obviously decreased. APN receptors in the hippocampus were increased in the hippocampus. AdipoRon treatment significantly rescued memory deficits in P301S mice. Besides, AdipoRon treatment was also detected to improve synaptic function, enhance mitochondrial fusion, and mitigate hyperphosphorylated tau accumulation in P301S mice and SY5Y cells. Mechanistically, AMPK/SIRT3 and AMPK/GSK3β signaling pathways are demonstrated to be involved in AdipoRon-mediated benefits on mitochondrial dynamics and tau accumulation, respectively, and inhibition of AMPK related pathways showed counteracted effects.

CONCLUSION

Our results demonstrated that AdipoRon treatment could significantly mitigate tau pathology, improve synaptic damage, and restore mitochondrial dynamics via the AMPK-related pathway, which provides a novel potential therapeutic approach to retard the progression of AD and other tauopathies diseases.

Methyl eugenol protects the kidney from oxidative damage in mice by blocking the Nrf2 nuclear export signal through activation of the AMPK/GSK3β axis

Disrupted redox homeostasis contributes to renal ischemia-reperfusion (IR) injury. Abundant natural products can activate nuclear factor erythroid-2-related factor 2 (Nrf2), thereby providing therapeutic benefits. Methyl eugenol (ME), an analog of the phenolic compound eugenol, has the ability to induce Nrf2 activity. In this study, we investigated the protective effects of ME against renal oxidative damage in vivo and in vitro. An IR-induced acute kidney injury (AKI) model was established in mice. ME (20 mg·kg-1·d-1, i.p.) was administered to mice on 5 consecutive days before IR surgery. We showed that ME administration significantly attenuated renal destruction, improved the survival rate, reduced excessive oxidative stress and inhibited mitochondrial lesions in AKI mice. We further demonstrated that ME administration significantly enhanced Nrf2 activity and increased the expression of downstream antioxidative molecules. Similar results were observed in vitro in hypoxia/reoxygenation (HR)-exposed proximal tubule epithelial cells following pretreatment with ME (40 μmol·L-1). In both renal oxidative damage models, ME induced Nrf2 nuclear retention in tubular cells. Using specific inhibitors (CC and DIF-3) and molecular docking, we demonstrated that ME bound to the binding pocket of AMPK with high affinity and activated the AMPK/GSK3β axis, which in turn blocked the Nrf2 nuclear export signal. In addition, ME alleviated the development of renal fibrosis induced by nonfatal IR, which is frequently encountered in the clinic. In conclusion, we demonstrate that ME modulates the AMPK/GSK3β axis to regulate the cytoplasmic-nuclear translocation of Nrf2, resulting in Nrf2 nuclear retention and thereby enhancing antioxidant target gene transcription that protects the kidney from oxidative damage.

Mechanism of Erzhiwan in treating osteoporosis based on molecular docking technology and molecular dynamics simulation

This experiment was a network pharmacology research based on the theoretical system of traditional Chinese medicine. TCMSP database, PubChem database, RCSB database, and SwissTargetPrediction database were used to study the effective chemical constituents of Ligustri lucidi Fructus and Ecliptae Herba in Erzhiwan, a traditional prescription for nourishing the liver and kidney. Then Genecards database, OMIM database, OMIM Gene Map, and Metascape database were used to study the therapeutic targets of osteoporosis. At last, Cytoscape 3.6.0 software, its built-in Bisogenet and CytoNCA, AutoDockTools-1.5.6 software, PYMOL-2.2.0 software, and Gromacs software, by drawing the relationship diagram between chemical components and disease targets, PPI network of disease, semi-flexible molecular docking technology, evaluation and analysis of enrichment pathway, and molecular dynamics simulation, were used to study the therapeutic mechanism of Erzhiwan on osteoporosis. It is found that the intervention and regulation of Erzhiwan on osteoporosis were mainly realized through multiple targets of active ingredients and multiple pathways, which provided support for the continued development of Erzhiwan.

Activation of Nrf2 signaling: A key molecular mechanism of protection against cardiovascular diseases by natural products

Cardiovascular diseases (CVD) are a group of cardiac and vascular disorders including myocardial ischemia, congenital heart disease, heart failure, hypertension, atherosclerosis, peripheral artery disease, rheumatic heart disease, and cardiomyopathies. Despite considerable progress in prophylaxis and treatment options, CVDs remain a leading cause of morbidity and mortality and impose an extremely high socioeconomic burden. Oxidative stress (OS) caused by disequilibrium in the generation of reactive oxygen species plays a crucial role in the pathophysiology of CVDs. Nuclear erythroid 2-related factor 2 (Nrf2), a transcription factor of endogenous antioxidant defense systems against OS, is considered an ideal therapeutic target for management of CVDs. Increasingly, natural products have emerged as a potential source of Nrf2 activators with cardioprotective properties and may therefore provide a novel therapeutic tool for CVD. Here, we present an updated comprehensive summary of naturally occurring products with cardioprotective properties that exert their effects by suppression of OS through activation of Nrf2 signaling, with the aim of providing useful insights for the development of therapeutic strategies exploiting natural products.

Britanin relieves ferroptosis-mediated myocardial ischaemia/reperfusion damage by upregulating GPX4 through activation of AMPK/GSK3β/Nrf2 signalling

CONTEXT

Ferroptosis was described as an important contributor to the myocardial ischaemia/reperfusion (MIR) injury, and britanin (Bri) was reported to exert antitumor and anti-inflammatory activities.

OBJECTIVE

Our study explores the effect and mechanism of Bri on MIR damage.

MATERIALS AND METHODS

The rat model of MIR was established by ligation of the left anterior descending coronary artery. Male Sprague-Dawley (SD) rats were divided into three groups: sham group (n = 6), MIR group (n = 6) and MIR + Bri group (n = 6; 50 mg/kg). Rats were intragastrically pre-treated with Bri or normal saline once daily for 3 days. To further verify the role and mechanism of Bri, H9C2 cells were subjected to hypoxia plus reoxygenation (H/R) to induce the in vitro model of MIR.

RESULTS

Compared with MIR rats, Bri significantly decreased infarct area (22.50% vs. 38.67%), myocardial apoptosis (23.00% vs. 41.5%), creatine phosphokinase (0.57 U/mL vs. 0.76 U/mL), and lactate dehydrogenase levels (3.18 U/mL vs. 5.17 U/mL), concomitant with alleviation of ferroptosis. Mechanistically, Bri treatment induced the activation of the adenosine monophosphate activated protein kinase (AMPK)/glycogen synthase kinase 3β (GSK3β)/nuclear factor erythroid 2-related factor 2 (Nrf2) pathway in vivo. In addition, the AMPK/GSK3β/Nrf2 pathway participated in the regulation of glutathione peroxidase 4 (GPX4) expression, and silencing of Nrf2 attenuated the effect of Bri on H/R-induced cell injury.

DISCUSSION AND CONCLUSIONS

Bri protected against ferroptosis-mediated MIR damage by upregulating GPX4 through activation of the AMPK/GSK3β/Nrf2 signalling, suggesting that Bri might become a novel therapeutic agent for MIR.

Butin Mitigates Memory Impairment in Streptozotocin-Induced Diabetic Rats by Inhibiting Oxidative Stress and Inflammatory Responses

It has been reported from the previous literature that butin restores mitochondrial dysfunction by modulation of oxidative stress and glutamate-induced neurotoxicity in mouse hippocampus HT22 cells. Butin also possesses an anti-Huntington's effect in rats. Considering the current background, this study was designed to evaluate the neuroprotective effect of butin against memory loss caused by streptozotocin (STZ). STZ (40 mg/kg) was intraperitoneally injected into rats. Three days later, diabetic rats were identified and included in the study. A total of 30 rats (12 nondiabetic and 18 diabetics) were grouped as Group A (control-non-diabetic rats) and Group B (STZ diabetic control) were treated with 1 mL of sodium CMC (0.5% w/v). Group C (STZ+ butin 25) were treated with butin 25 mg/kg. Group D (STZ+ butin 50) and Group E (butin per se) were administered with butin 50 mg/kg. Each therapy was administered orally once each day for 15-day. The Morris water maze and the Y-maze behavioural tests were run throughout the experimental programme. Animals were put to death on day 15 and their brains were removed for biochemical assays (CAT, SOD, GSH, MDA, nitrite, acetylcholinesterase (AchE), IL-1, and mitochondrial enzyme complexes). Rats with neurobehavioral impairments brought on by STZ have less spontaneous movement, learning capacity, and memory. Additionally, STZ decreased endogenous antioxidants and increased pro-inflammatory cytokines, nitrite, MDA, and AchE. Neurobehavioral deficits and metabolic markers were dramatically improved by butin.

1,25-D3 attenuates cerebral ischemia injury by regulating mitochondrial metabolism via the AMPK/AKT/GSK3β pathway

The brain injury caused by cerebral ischemia-reperfusion is related to mitochondrial damage. Maintaining the normal function of mitochondria, promoting angiogenesis, protecting neuronal cells, and resisting oxidative stress are the keys to functional recovery after acute ischemic stroke. In this study, we established a middle cerebral artery occlusion (MCAO) model and investigated the effects of 1α,25-dihydroxyvitamin D3 (VitD or 1,25-D3) on mitochondrial function via the adenosine 5'-monophosphate-activated protein kinase (AMPK)/protein kinase B (AKT)/glycogen synthase kinase-3β (GSK-3β) signaling pathway in rats with cerebral ischemia-reperfusion injury. The neurological function and infarct size were measured in each group. Hematoxylin-eosin, neuronal nucleus, and Nissl staining procedures were conducted to observe the morphology and number of the cerebral cortical neurons. Western blotting was then used to analyze p-AMPK, vitamin D receptor (VDR), p-GSK-3β, p-AKT, P53, cytochrome C (CytC), TGF-β, and vascular endothelial growth factor (VEGF) in mitochondria. Immunofluorescence staining was used to observe the expression of CytC and caspase-3. Succinate dehydrogenase, ATPase, reactive oxygen species, and malondialdehyde were detected by kits. RT-qPCR was used to analyze TGF-β, VEGF, P53, and CytC mRNA. The results revealed that the cerebral infarct volume, neurological function score, apoptotic protein P53, CytC, caspase-3, reactive oxygen species, and malondialdehyde were significantly increased in MCAO rats. 1,25-D3 reduced the infarct size and neurological function score, activated VDR, upregulated TGF-β, p-AMPK, p-AKT, p-GSK-3β, VEGF, ATP, and succinate dehydrogenase, and downregulated P53, CytC, caspase-3, reactive oxygen species, and malondialdehyde. As an antagonist of VDRs, pyridoxal-5-phosphate could partially block the neuroprotective effect of 1,25-D3. In conclusion, 1,25-D3 activated AMPK/AKT/GSK-3β signaling and VDRs, inhibited P53, CytC, and caspase-3, increased TGF-β and VEGF, regulated mitochondrial metabolism, reduced neuronal apoptosis, promoted vascular growth, and exerted neuroprotective effects. These findings suggest that this signaling pathway may be an effective target for the treatment of ischemic stroke.

Dexmedetomidine attenuates myocardial ischemia/reperfusion-induced ferroptosis via AMPK/GSK-3β/Nrf2 axis

The present study aimed to investigate whether dexmedetomidine (Dex) exerts cardioprotection effect through inhibiting ferroptosis. Myocardial ischemia/reperfusion injury (MIRI) was induced in Sprague-Dawley rats in Langendorff preparation. The hemodynamic parameters were recorded. Triphenyltetrazolium chloride (TTC) staining was used to determine infarct size. In the in vitro study, the model of hypoxia/reoxygenation (HR) was established in H9c2 cells. Cell viability and apoptosis were detected using cell counting kit 8 (CCK-8), and AV/PI dual staining respectively. Lipid peroxidation as measured by the fluorescence of the fatty acid analog C11-BODIPY581/591 probe and intracellular ferrous iron levels were measured by fluorescence of Phen Green SK (PGSK) probe, whereas immunofluorescence and transmission electron microscopy were also used to examine ferroptosis. Protein levels were investigated by Western blot. The interactions of AMPK/GSK-3β signaling with Nrf2 were also assessed through AMPK inhibition and GSK-3β overexpression. Our findings indicated that Dex significantly alleviated myocardial infarction, improved heart function, and decreased HR-induced accumulation of Fe²⁺ and lipid peroxidation in cardiomyocytes. Dex significantly increased the expression levels of Nrf2, SLC7A11, and GPX4. However, inhibition of Nrf2 by ML385 blunted the protective effect of Dex in HR-treated H9c2 cells. Inhibition of AMPK with a specific inhibitor or siRNA decreased the expression levels of phosphorylation of GSK-3β and Nrf2 induced by Dex. Overexpression of GSK-3β resulted in lower levels of nuclear Nrf2, whereas depression of GSK-3β enhanced expressions of nuclear Nrf2. In conclusion, Dex protects hearts against MIRI-induced ferroptosis via activation of Nrf2 through AMPK/GSK-3β signaling pathway.

AMPK: The key to ischemia-reperfusion injury

Ischemia-reperfusion injury (IRI) refers to a syndrome in which tissue damage is further aggravated and organ function further deteriorates when blood flow is restored after a period of tissue ischemia. Acute myocardial infarction, stress ulcer, pancreatitis, intestinal ischemia, intermittent claudication, acute tubular necrosis, postshock liver failure, and multisystem organ failure are all related to reperfusion injury. AMP-activated protein kinase (AMPK) has been identified in multiple catabolic and anabolic signaling pathways. The functions of AMPK during health and diseases are intriguing but still need further research. Except for its conventional roles as an intracellular energy switch, emerging evidence reveals the critical role of AMPK in IRI as an energy-sensing signal molecule by regulating metabolism, autophagy, oxidative stress, inflammation, and other progressions. At the same time, drugs based on AMPK for the treatment of IRI are constantly being researched and applied in clinics. In this review, we summarize the mechanisms underlying the effects of AMPK in IRI and describe the AMPK-targeting drugs in treatment, hoping to increase the understanding of AMPK in IRI and provide new insights into future clinical treatment.

LncRNA FOXD3-AS1 aggravates myocardial ischemia/reperfusion injury by inactivating the Redd1/AKT/GSK3β/Nrf2 signaling pathway via the miR-128/TXNIP axis

Long noncoding RNA forkhead box D3-antisense RNA 1 (FOXD3-AS1) is associated with cardiovascular diseases, but its roles in myocardial ischemia/reperfusion (I/R) injury and the related signaling pathway have not been fully reported. We aimed to investigate the roles and mechanism of action of FOXD3-AS1 in myocardial I/R injury. An in vivo myocardial I/R injury mouse model and an in vitro hypoxia/reoxygenation (H/R) cardiomyocyte model was established. Quantitative reverse transcription-polymerase chain reaction, western blotting, and immunofluorescent assays were performed to examine the expression levels of FOXD3-AS1, microRNA (miR)-128, thioredoxin-interacting protein/regulation of development and DNA damage response 1/protein kinase B/glycogen synthase kinase 3β/nuclear factor erythroid 2-related factor 2 (TXNIP/Redd1/AKT/GSK3β/Nrf2) pathway-related proteins and apoptosis-related proteins. The interactions between FOXD3-AS1 and miR-128 and miR-128 and TXNIP were analyzed by Spearman's correlation test, predicted by ENCORI, and verified by dual-luciferase reporter assay. In addition, the levels of cardiac injury markers and oxidative stress markers were evaluated by corresponding kits. Cell Counting Kit-8 assays and flow cytometry were performed to assess cell viability and apoptosis. Hematoxylin and eosin staining was applied to observe the effect of FOXD3-AS1 on the morphology of myocardial I/R injured tissues. The results showed that the FOXD3-AS1 and TXNIP were highly expressed, whereas miR-128 was expressed at low levels in I/R myocardial tissues and H/R-induced H9c2 cells. FOXD3-AS1 directly targeted miR-128 to reduce its expression. TXNIP was confirmed as a downstream target of miR-128. Knockdown of FOXD3-AS1 led to the alleviation of I/R injury in vivo and in vitro. FOXD3-AS1 enhanced the expression of TXNIP by sponging miR-128, which inhibited the Redd1/AKT/GSK3β/Nrf2 pathway. Both inhibition of miR-128 and overexpression of TXNIP reversed the cardioprotective effect of FOXD3-AS1 small interfering RNA in H/R-induced H9c2 cells.

Modulation of integrin receptor by polyphenols: Downstream Nrf2-Keap1/ARE and associated cross-talk mediators in cardiovascular diseases

As a group of heterodimeric and transmembrane glycoproteins, integrin receptors are widely expressed in various cell types overall the body. During cardiovascular dysfunction, integrin receptors apply inhibitory effects on the antioxidative pathways, including nuclear factor erythroid 2-related factor 2 (Nrf2)-Kelch like ECH Associated Protein 1 (Keap1)/antioxidant response element (ARE) and interconnected mediators. As such, dysregulation in integrin signaling pathways influences several aspects of cardiovascular diseases (CVDs) such as heart failure, arrhythmia, angina, hypertension, hyperlipidemia, platelet aggregation and coagulation. So, modulation of integrin pathway could trigger the downstream antioxidant pathways toward cardioprotection. Regarding the involvement of multiple aforementioned mediators in the pathogenesis of CVDs, as well as the side effects of conventional drugs, seeking for novel alternative drugs is of great importance. Accordingly, the plant kingdom could pave the road in the treatment of CVDs. Of natural entities, polyphenols are multi-target and accessible phytochemicals with promising potency and low levels of toxicity. The present study aims at providing the cardioprotective roles of integrin receptors and downstream antioxidant pathways in heart failure, arrhythmia, angina, hypertension, hyperlipidemia, platelet aggregation and coagulation. The potential role of polyphenols has been also revealed in targeting the aforementioned dysregulated signaling mediators in those CVDs.

Sea Buckthorn Proanthocyanidins are the Protective Agent of Mitochondrial Function in Macrophages Under Oxidative Stress

Sea buckthorn proanthocyanidins (SBP) are the most important antioxidant components of sea buckthorn, which are widely used in functional foods and cosmetics. Studies have shown that SBP have significant protective effects on macrophages against oxidative stress induced by hydrogen peroxide (H₂O₂). However, the mechanism remains uncertain. In the present study, we explored the effects of SBP on mitochondrial function and the mechanism of their protective effects against oxidative stress in cells. Our results showed that SBP could increase mitochondrial membrane potential, inhibit mPTP opening, reduce mitochondrial swelling, and enhance mitochondrial synthesis and metabolism. Thus, they alleviated oxidative damage and protected the cells against mitochondrial function. Western blot analysis showed that SBP had a protective effect on RAW264.7 cells by activating the AMPK-PGC1α-Nrf2 pathway. These results showed that SBP alleviated mitochondrial damage and dysfunction caused by oxidative stress. This study revealed the mechanism of SBP in reducing oxidative damage and provided a theoretical basis for further research on natural bioactive compounds to exert antioxidant activity and prevent arteriosclerosis and other diseases.

Application of Biotransformation-Guided Purification in Chinese Medicine: An Example to Produce Butin from Licorice

Natural compounds are considered treasures in biotechnology; however, in the past, the process of discovering bioactive compounds is time consuming, and the purification and validation of the biofunctions and biochemistry of compounds isolated from a medicinal herb are tedious tasks. In this study, we developed an economical process called biotransformation-guided purification (BGP), which we applied to analyze licorice, a traditional Chinese medicine widely used in many therapies. This medicinal herb contains various flavonoids and triterpenoids and, thus, is a suitable material used to assess the ability of BGP to identify and produce bioactive compounds. In the BGP process, the ethyl acetate extract of a commercial licorice medicine was partially purified into three fractions by Sephadex LH-20 chromatography, and Bacillus megaterium tyrosinase (BmTYR) was used to catalyze the biotransformation of the extract from each fraction. One of the products produced via BmTYR-driven biotransformation was purified from the biotransformation-positive extract using preparative C-18 high-performance liquid chromatography, and it was identified as butin (3′-hydroxyliquiritigenin) through nucleic magnetic resonance and mass spectral analyses. Butin was produced from liquiritigenin through BmTYR-catalyzed hydroxylation, with commercial liquiritigenin as the biotransformation precursor. The proposed alternative approach quickly identified and isolated the biotransformed butin from licorice. Moreover, butin demonstrated an antioxidant activity that is stronger by over 100-fold compared with that of its precursor (liquiritigenin). This study showed that the economical BGP process could quickly obtain and validate bioactive molecules from crude extracts of medicinal herbs.

The Beneficial Effects of Chinese Herbal Monomers on Ameliorating Diabetic Cardiomyopathy via Nrf2 Signaling

Diabetic cardiomyopathy (DCM) is the main factor responsible for poor prognosis and survival in patients with diabetes. The highly complex pathogenesis of DCM involves multiple signaling pathways, including nuclear factor-κB (NF-κB) signaling pathway, adenosine monophosphate-activated protein kinase (AMPK) signaling pathway, phosphatidylinositol 3-kinase-protein kinase B (Akt) signaling pathway, mitogen-activated protein kinase (MAPK) signaling pathway, and transforming growth factor-β (TGF-β) signaling pathway. Nuclear factor erythroid-2-related factor 2 (Nrf2) seems essential to the amelioration of the progression of DCM, not only through counterbalancing oxidative stress, but also through interacting with other signaling pathways to combat inflammation, the disorder in energy homeostasis and insulin signaling, and fibrosis. It has been evidenced that Chinese herbal monomers could attenuate DCM through the crosstalk of Nrf2 with other signaling pathways. This article has summarized the pathogenesis of DCM (especially in oxidative stress), the beneficial effects of ameliorating DCM via the Nrf2 signaling pathway and its crosstalk, and examples of Chinese herbal monomers. It will facilitate pharmacological research and development to promote the utilization of traditional Chinese medicine in DCM.

Reactive oxygen species in cardiovascular diseases: an update

Cardiovascular diseases are among the leading causes of death worldwide, imposing major health threats. Reactive oxygen species (ROS) are one of the most important products from the process of redox reactions. In the onset and progression of cardiovascular diseases, ROS are believed to heavily influence homeostasis of lipids, proteins, DNA, mitochondria, and energy metabolism. As ROS production increases, the heart is damaged, leading to further production of ROS. The vicious cycle continues on as additional ROS are generated. For example, recent evidence indicated that connexin 43 (Cx43) deficiency and pyruvate kinase M2 (PKM2) activation led to a loss of protection in cardiomyocytes. In this context, a better understanding of the mechanisms behind ROS production is vital in determining effective treatment and management strategies for cardiovascular diseases.

Butin Attenuates Arthritis in Complete Freund's Adjuvant-Treated Arthritic Rats: Possibly Mediated by Its Antioxidant and Anti-Inflammatory Actions

The present research work was planned to evaluate the antioxidant and anti-inflammatory actions of butin in preventing complete Freund’s adjuvant-induced arthritis in rats. Adult Wistar rats (200–240 g) were segregated equally into four groups: Group I (normal) and Group II complete Freund’s adjuvant (CFA control) were administered orally with 3 ml/kg of 0.5% SCMC (vehicle); Group III and Group IV were test groups and orally administered 25 and 50 mg/kg of butin. These oral treatments were administered for a total of 21 days. In the 21-day treatment schedule, on the first day, animals from group I (normal control) were injected a single dose of normal saline (0.1 ml) intradermally into one of the hind paws, and animals from Group II to IV were injected CFA (0.1 ml) intradermally into one of the hind paws. During the treatment schedule, the volume of the hind paw and body weight were recorded at every 7 days intervals, and animals were scored for severe arthritis on days 17, 19, and 21. On the 22nd day, samples of blood were withdrawn by puncturing the retro-orbital sinus for analysis of RBC, WBC, hemoglobin, ALT, AST, ALP, PGE2, and cytokines. After blood withdrawal, animals were euthanized; the paw was separated by cutting at the ankle joint and used for analysis of oxidative stress and antioxidant parameters, as well as for the histopathological study. Administration of butin to CFA-treated animals significantly attenuated the CFA-induced inflammatory response, oxidative stress, and reversed the histopathological alteration towards normal. According to the findings, butin has anti-inflammatory and anti-arthritic properties in rats with CFA-induced arthritis.

Vitexin attenuates autoimmune hepatitis in mouse induced by syngeneic liver cytosolic proteins via activation of AMPK/AKT/GSK-3β/Nrf2 pathway

Autoimmune hepatitis (AIH) is a chronic progressive liver disease that currently does not have a successful therapeutic option. Vitexin, a bioflavonoid isolated from various medicinal plants, possesses a variety of activities; however, whether vitexin protects against AIH remains unclear. Therefore, the current study aims to investigate the hepatoprotective effects and mechanism of action of vitexin in both an experimental autoimmune hepatitis (EAH) mouse model and in D-galactosamine/lipopolysaccharide (D-GalN/LPS)-induced hepatocyte injury. Syngeneic liver antigen S100 was used to establish EAH. Vitexin treatment significantly decreased the infiltration of inflammatory and CD4+ T cells in the liver, reduced ALT and AST levels in the serum and attenuated hepatic injury due to oxidative stress. Moreover, vitexin mitigated the upregulation of Bax and cleaved caspase-3 and the downregulation of Bcl-2 in the livers of AIH mice. These regulations were accompanied by not only increased phosphorylation of AMPK, AKT and GSK-3β but also activation of Nrf2. Furthermore, vitexin inhibited apoptosis and the overexpression of inflammatory cytokines in D-GalN/LPS-treated AML12 cells. In addition, vitexin enhanced the phosphorylation of AMPK, AKT and GSK-3β. When AML12 cells were treated with an inhibitor of AMPK/AKT or specific siRNA targeting Nrf2, vitexin did not further induce the activation of Nrf2/HO-1. A molecular docking study confirmed that vitexin could interact with AMPK through hydrogen bonding interactions. In conclusion, vitexin ameliorated hepatic injury in EAH mice through activation of the AMPK/AKT/GSK-3β pathway and upregulation of the Nrf2 gene.

Gut bacterial metabolite Urolithin A inhibits myocardial fibrosis through activation of Nrf2 pathway in vitro and in vivo

Background

Myocardial fibrosis after myocardial infarction (MI) is one of the leading causes of cardiovascular diseases. Cardiac fibroblasts (CFs) are activated and promoted by MI to undergo myofibroblast transformation (CMT). Urolithin A (UA) is an active and effective gut metabolite derived from polyphenolics of berries and pomegranate fruits, which has been reported to have anti-inflammatory and anti-oxidant functions. However, whether UA affects the CMT process during myocardial fibrosis remains unclear.

Methods

TGF-β1-treated primary rat cardiac fibroblasts were used for in vitro study. Cell proliferation ability was evaluated by MTT assay. Cell migration and invasion abilities were tested by wound healing and Transwell assays. The expression of CMT process-related markers were measured by qRT-PCR and western blot. The rat MI model was established by left anterior descending coronary artery (LAD) ligation and evaluated by H&E and Masson staining.

Results

Our data demonstrated that UA treatment could inhibit the CMT process in TGF-β1-induced CFs, including cell proliferation, migration and invasion abilities. Knocking down of Nrf2, which was activated by UA treatment, could mitigate the effects of UA treatment on CMT process. Moreover, in vivo administration of UA in rat MI model successfully up-regulated Nrf2 expression and improved the myocardial damage and fibrosis.

Conclusions

The study discovered the function and mechanism of UA on myocardial fibrosis and demonstrated the protective effects of UA administration through activation of Nrf2 pathway.

AMPK signaling in diabetes mellitus, insulin resistance and diabetic complications: A pre-clinical and clinical investigation

Diabetes mellitus (DM) is considered as a main challenge in both developing and developed countries, as lifestyle has changed and its management seems to be vital. Type I and type II diabetes are the main kinds and they result in hyperglycemia in patients and related complications. The gene expression alteration can lead to development of DM and related complications. The AMP-activated protein kinase (AMPK) is an energy sensor with aberrant expression in various diseases including cancer, cardiovascular diseases and DM. The present review focuses on understanding AMPK role in DM. Inducing AMPK signaling promotes glucose in DM that is of importance for ameliorating hyperglycemia. Further investigation reveals the role of AMPK signaling in enhancing insulin sensitivity for treatment of diabetic patients. Furthermore, AMPK upregulation inhibits stress and cell death in β cells that is of importance for preventing type I diabetes development. The clinical studies on diabetic patients have shown the role of AMPK signaling in improving diabetic complications such as brain disorders. Furthermore, AMPK can improve neuropathy, nephropathy, liver diseases and reproductive alterations occurring during DM. For exerting such protective impacts, AMPK signaling interacts with other molecular pathways such as PGC-1α, PI3K/Akt, NOX4 and NF-κB among others. Therefore, providing therapeutics based on AMPK targeting can be beneficial for amelioration of DM.

Green Tea Polyphenols Alleviate Hydrogen Peroxide-Induced Oxidative Stress, Inflammation, and Apoptosis in Bovine Mammary Epithelial Cells by Activating ERK1/2–NFE2L2–HMOX1 Pathways

Oxidative stress (OS) is one of the main limiting factors affecting the length of lactation and milk quality in dairy cows. For high-producing dairy cows, the OS of mammary glands is a serious problem. Green tea polyphenols (GTP), found mainly in tea, are a combination of many phenols. GTP have a good effect on antioxidation, inflammation resistance, obesity, fat cell metabolism improvement, and lowering of blood lipid. Therefore, we studied the role of GTP on OS in dairy cows and further investigated whether GTP alleviates oxidative damage of bovine mammary epithelial cells (BMECs) induced by hydrogen peroxide (H2O2) and its underlying molecular mechanism. In this study, 500 μM of H2O2 for 12 h incubation was chosen as the condition of the OS model of BMECs. In addition, the present results found that treatment with GTP alleviated the oxidative damage induced by H2O2 [the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) were significantly increased, and the contents of malondialdehyde (MDA), 8-isoprostaglandin (8-iso-PG), 8-oxo-deoxyguanosine (8-OHdG), and protein carbonyl (PC) and caspase-3 and caspase-9 activities were significantly reduced]. These effects are related to the activation of the erythrocyte-derived nuclear factor 2-like protein 2 (NFE2L2) signaling pathway and the inactivation of the caspase/Bcl-2 apoptotic pathway. When NFE2L2 short interfering RNA (siRNA) was used to downregulate the expression of NFE2L2 in cultured BMECs, NFE2L2-siRNA transfection abolished the protective effect of GTP on H2O2-induced intracellular reactive oxygen species (ROS) accumulation and apoptosis. In addition, the mitogen-activated protein kinase (MAPK) inhibition test further proved that GTP relieved H2O2-induced oxidative damage by activating the NFE2L2 signaling pathway, which was achieved by activating the extracellular-regulated kinase 1/2 (ERK1/2) signaling pathway. Overall, the results indicate that GTP has a beneficial effect on the redox balance of BMECs. In addition, GTP might be a latent antioxidant in vivo, which can be administered to ruminants during stressful periods such as the perinatal period.

Drug repositioning of COVID-19 based on mixed graph network and ion channel

Research on the relationship between drugs and targets is the key to precision medicine. Ion channel is a kind of important drug targets. Aiming at the urgent needs of corona virus disease 2019 (COVID-19) treatment and drug development, this paper designed a mixed graph network model to predict the affinity between ion channel targets of COVID-19 and drugs. According to the simplified molecular input line entry specification (SMILES) code of drugs, firstly, the atomic features were extracted to construct the point sets, and edge sets were constructed according to atomic bonds. Then the undirected graph with atomic features was generated by RDKit tool and the graph attention layer was used to extract the drug feature information. Five ion channel target proteins were screened from the whole SARS-CoV-2 genome sequences of NCBI database, and the protein features were extracted by convolution neural network (CNN). Using attention mechanism and graph convolutional network (GCN), the extracted drug features and target features information were connected. After two full connection layers operation, the drug-target affinity was output, and model was obtained. Kiba dataset was used to train the model and determine the model parameters. Compared with DeepDTA, WideDTA, graph attention network (GAT), GCN and graph isomorphism network (GIN) models, it was proved that the mean square error (MSE) of the proposed model was decreased by 0.055, 0.04, 0.001, 0.046, 0.013 and the consistency index (CI) was increased by 0.028, 0.016, 0.003, 0.03 and 0.01, respectively. It can predict the drug-target affinity more accurately. According to the prediction results of drug-target affinity of SARS-CoV-2 ion channel targets, seven kinds of small molecule drugs acting on five ion channel targets were obtained, namely SCH-47112, Dehydroaltenusin, alternariol 5-o-sulfate, LPA1 antagonist 1, alternariol, butin, and AT-9283.These drugs provide a reference for drug repositioning and precise treatment of COVID-19.

Plant-Derived Compounds as Promising Therapeutics for Vitiligo

Vitiligo is the most common depigmenting disorder characterized by white patches in the skin. The pathogenetic origin of vitiligo revolves around autoimmune destruction of melanocytes in which, for instance, oxidative stress is responsible for melanocyte molecular, organelle dysfunction and melanocyte specific antigen exposure as well as melanocyte cell death and thus serves as an important contributor for vitiligo progression. In recent years, natural products have shown a wide range of pharmacological bioactivities against many skin diseases, and this review focuses on the effects and mechanisms of natural compounds against vitiligo models. It is showed that some natural compounds such as flavonoids, phenols, glycosides and coumarins have a protective role in melanocytes and thereby arrest the depigmentation, and, additionally, Nrf2/HO-1, MAPK, JAK/STAT, cAMP/PKA, and Wnt/β-catenin signaling pathways were reported to be implicated in these protective effects. This review discusses the great potential of plant derived natural products as anti-vitiligo agents, as well as the future directions to explore.

Chrysanthemi Flos extract alleviated acetaminophen-induced rat liver injury via inhibiting oxidative stress and apoptosis based on network pharmacology analysis

CONTEXT

Acetaminophen (APAP) overdose is the leading cause of drug-induced liver injury. Bianliang ziyu, a variety of Chrysanthemum morifolium Ramat. (Asteraceae), has potential hepatoprotective effect. However, the mechanism is not clear yet.

OBJECTIVE

To investigate the hepatoprotective activity and mechanism of Bianliang ziyu flower ethanol extract (BZE) on APAP-induced rats based on network pharmacology.

MATERIALS AND METHODS

Potential pathways of BZE were predicted by network pharmacology. Male Sprague-Dawley rats were pre-treated with BZE (110, 220 and 440 mg/kg, i.g.) for eight days, and then APAP (800 mg/kg, i.g.) was used to induce liver injury. After 24 h, serum and liver were collected for biochemical detection and western blot measurement.

RESULTS

Network pharmacology indicated that liver-protective effect of BZE was associated with its antioxidant and anti-apoptotic efficacy. APAP-induced liver pathological change was alleviated, and elevated serum AST and ALT were reduced by BZE (440 mg/kg) (from 66.45 to 22.64 U/L and from 59.59 to 17.49 U/L, respectively). BZE (440 mg/kg) reduced the ROS to 65.50%, and upregulated SOD and GSH by 212.92% and 175.38%, respectively. In addition, BZE (440 mg/kg) increased levels of p-AMPK, p-GSK3β, HO-1 and NQO1, ranging from 1.66- to 10.29-fold compared to APAP group, and promoted nuclear translocation of Nrf2. BZE also inhibited apoptosis induced by APAP through the PI3K-Akt pathway and restored the ability of mitochondrial biogenesis.

DISCUSSION AND CONCLUSIONS

Our study demonstrated that BZE protected rats from APAP-induced liver injury through antioxidant and anti-apoptotic pathways, suggesting BZE could be further developed as a potential liver-protecting agent.

The interplay among oxidative stress, brain insulin resistance and AMPK dysfunction contribute to neurodegeneration in type 2 diabetes and Alzheimer disease

Alzheimer's disease (AD) is the most common form of dementia in the elderly followed by vascular dementia. In addition to clinically diagnosed dementia, cognitive dysfunction has been reported in diabetic patients. Recent studies are now beginning to recognize type 2 diabetes mellitus (T2DM), characterized by chronic hyperglycemia and insulin resistance, as a risk factor for AD and other cognitive disorders. While studies on insulin action have remained traditionally in the domain of peripheral tissues, the detrimental effects of insulin resistance in the central nervous system on cognitive dysfunction are increasingly being reported in recent clinical and preclinical studies. Brain functions require continuous supply of glucose and oxygen and a tight regulation of metabolic processes. Loss of this metabolic regulation has been proposed to be a contributor to memory dysfunction associated with neurodegeneration. Within the above scenario, this review will focus on the interplay among oxidative stress (OS), insulin resistance and AMPK dysfunctions in the brain by highlighting how these neurotoxic events contribute to neurodegeneration. We provide an overview on the detrimental effects of OS on proteins regulating insulin signaling and how these alterations impact cell metabolic dysfunctions through AMPK dysregulation. Such processes, we assert, are critically involved in the molecular pathways that underlie AD.

SFRP2 Improves Mitochondrial Dynamics and Mitochondrial Biogenesis, Oxidative Stress, and Apoptosis in Diabetic Cardiomyopathy

BACKGROUND

The mitochondrial dynamics and mitochondrial biogenesis are essential for maintaining the bioenergy function of mitochondria in diabetic cardiomyopathy (DCM). Previous studies have revealed that secreted frizzled-related protein 2 (SFRP2) is beneficial against apoptosis and oxidative stress. However, no research has confirmed whether SFRP2 regulates oxidative stress and apoptosis through mitochondrial function in DCM.

METHODS

Exposure of H9C2 cardiomyocytes in high glucose (HG) 25 mM and palmitic acid (PAL) 0.2 mM was used to simulate DCM in vitro. H9C2 cells with SFRP2 overexpression or SFRP2 knockdown were constructed and cultured under glucolipotoxicity or normal glucose conditions. An SD rat model of type 2 diabetes mellitus (T2DM) was generated using a high-fat diet combined with a low-dose STZ injection. Overexpression of SFRP2 in the rat model was generated by using an adeno-associated virus approach. CCK-8, TUNEL assay, and DHE staining were used to detect cell viability, and MitoTracker Red CMXRos was used to detect changes in mitochondrial membrane potential. We used qRT-PCR and western blot to further explore the mechanisms of SFRP2 regulating mitochondrial dynamics through the AMPK/PGC1-α pathway to improve diabetic cardiomyocyte injury.

RESULTS

Our results indicated that SFRP2 was significantly downregulated in H9C2 cells and cardiac tissues in T2DM conditions, accompanied by decreased expression of mitochondrial dysfunction. The mitochondrial membrane potential was reduced, and the cells were led to oxidative stress injury and apoptosis. Furthermore, the overexpression of SFRP2 could reverse apoptosis and promote mitochondrial function in T2DM conditions in vitro and in vivo. We also found that silencing endogenous SFRP2 could further promote glucolipotoxicity-induced mitochondrial dysfunction and apoptosis in cardiomyocytes, accompanied by downregulation of p-AMPK.

CONCLUSION

SFRP2 exerted cardioprotective effects by salvaging mitochondrial function in an AMPK-PGC1-α-dependent manner, which modulates mitochondrial dynamics and mitochondrial biogenesis, reducing oxidative stress and apoptosis. SFRP2 may be a promising therapeutic biomarker in DCM.

Alleviation of glucolipotoxicity-incurred cardiomyocyte dysfunction by Z-ligustilide involves in the suppression of oxidative insult, inflammation and fibrosis

Diabetes mellitus ranks as a major risk cause for disability and death around the world due to its complications, especially diabetic cardiomyopathy (DCM). Glucolipotoxicity is one of the critical causal factors of DCM. Recent finding confirms the beneficial roles of Z-ligustilide in diabetes mellitus. Nevertheless, its efficacy in DCM remains elusive. Here, Z-ligustilide elevated high glucose/high palmitic acid (HG/P)-inhibited cell viability and attenuated HG/P-induced cell apoptosis, caspase-3 activity, pro-apoptotic Bax and anti-apoptotic Bcl-2 protein expression. Furthermore, Z-ligustilide alleviated HG/P-evoked oxidative damage by decreasing HG/P-induced elevation in ROS, lactate dehydrogenase (LDH) and malondialdehyde (MDA) leakage, but increasing antioxidant enzyme-superoxide dismutase (SOD) and glutathione (GSH) levels suppressed by HG/P. Concomitantly, Z-ligustilide attenuated HG/P-induced cardiomyocyte fibrosis by increasing MMP-14 expression and diminishing HG/P-enhanced fibrotic protein expression, including collagen I, collagen II and TGF-β. Mechanistically, Z-ligustilide offset the adverse effects of HG/P on the activation of the AMPK/GSK-3β/Nrf2 pathway. Importantly, blocking the AMPK signaling overturned the protective efficacy of Z-ligustilide against HG/P-induced cardiomyocyte oxidative damage, inflammation and fibrosis. Together, these findings highlight that Z-ligustilide may alleviate glucolipotoxicity-induced cardiomyocyte dysfunction by regulating cell oxidative injury, inflammation and fibrosis via the AMPK/GSK-3β/Nrf2 pathway. Consequently, Z-ligustilide may represent a promising therapeutic agent against DCM by restoring cardiomyocyte dysfunction.

Visnagin prevents isoproterenol-induced myocardial injury by attenuating oxidative stress and inflammation and upregulating Nrf2 signaling in rats

Oxidative tissue injury and inflammatory responses play major roles in cardiovascular diseases and heart failure. Visnagin (VIS) is a natural bioactive component of Ammi visnaga, with promising radical scavenging and anti-inflammatory activities. This study explored the protective effect of VIS against isoproterenol (ISO)-induced acute myocardial injury and oxidative stress in rats. VIS was supplemented for 14 days, and the rats received ISO (100 mg/kg) twice at an interval of 24 h. ISO-induced myocardial injury was characterized by elevated serum CK-MB, LDH, and troponin-I associated with increased heart weight and several histopathological changes. ISO increased reactive oxygen species (ROS), malondialdehyde (MDA), NF-κB p65, TNF-α, IL-6, and decreased glutathione and antioxidant enzymes in rats' hearts. VIS prevented myocardial injury and ameliorated the cardiac function markers, ROS, MDA, NF-κB p65, and pro-inflammatory cytokines in ISO-intoxicated rats. In addition, VIS decreased Bax mRNA and caspases, and upregulated Nrf2, HO-1, Bcl-2, and PPARγ. Molecular docking simulations revealed the binding method of VIS to NF-κB, Keap1, and PPARγ. In conclusion, VIS protects against ISO-induced acute myocardial injury by attenuating oxidative tissue injury and reducing key inflammatory and apoptosis markers. In vivo and in silico results showed that activation of Nrf2/HO-1 signaling and PPARγ mediates the cardioprotective effect of VIS.

Nrf2 for cardiac protection: pharmacological options against oxidative stress

Myocardial ischemia or reperfusion increases the generation of reactive oxygen species (ROS) from damaged mitochondria, NADPH oxidases, xanthine oxidase, and inflammation. ROS can be removed by eight endogenous antioxidant and redox systems, many components of which are expressed under the influence of the activated Nrf2 transcription factor. Transcriptomic profiling, sequencing of Nrf2-bound DNA, and Nrf2 gene knockout studies have revealed the power of Nrf2 beyond the antioxidant and detoxification response, from tissue recovery, repair, and remodeling, mitochondrial turnover, and metabolic reprogramming to the suppression of proinflammatory cytokines. Multifaceted regulatory mechanisms for Nrf2 protein levels or activity have been mapped to its functional domains, Nrf2-ECH homology (Neh)1-7. Oxidative stress activates Nrf2 via nuclear translocation, de novo protein translation, and increased protein stability due to removal of the Kelch-like ECH-associated protein 1 (Keap1) checkpoint, or the inactivation of β-transducin repeat-containing protein (β-TrCP), or Hmg-CoA reductase degradation protein 1 (Hrd1). The promise of small-molecule Nrf2 inducers from natural products or derivatives is discussed here. Experimental evidence is presented to support Nrf2 as a lead target for drug development to further improve the treatment outcome for myocardial infarction (MI).

LncRNA Chaer Prevents Cardiomyocyte Apoptosis From Acute Myocardial Infarction Through AMPK Activation

Long non-coding RNA (lncRNA) is widely reported to be involved in cardiac (patho)physiology. Acute myocardial infarction, in which cardiomyocyte apoptosis plays an important role, is a life-threatening disease. Here, we report the lncRNA Chaer that is anti-apoptotic in cardiomyocytes during Acute myocardial infarction. Importantly, lncRNA Chaer is significantly downregulated in both oxygen-glucose deprivation (oxygen-glucose deprivation)-treated cardiomyocytes in vitro and AMI heart. In vitro, overexpression of lncRNA Chaer with adeno virus reduces cardiomyocyte apoptosis induced by OGD-treated while silencing of lncRNA Chaer increases cardiomyocyte apoptosis instead. In vivo, forced expression of lncRNA Chaer with AAV9 attenuates cardiac apoptosis, reduces infarction area and improves mice heart function in AMI. Interestingly, overexpression of lncRNA Chaer promotes the phosphorylation of AMPK, and AMPK inhibitor Compound C reverses the overexpression of lncRNA Chaer effect of reducing cardiomyocyte apoptosis under OGD-treatment. In summary, we identify the novel ability of lncRNA Chaer in regulating cardiomyocyte apoptosis by promoting phosphorylation of AMPK in AMI.

Ferroptosis and Its Potential Role in Metabolic Diseases: A Curse or Revitalization?

Ferroptosis is classified as an iron-dependent form of regulated cell death (RCD) attributed to the accumulation of lipid hydroperoxides and redox imbalance. In recent years, accumulating researches have suggested that ferroptosis may play a vital role in the development of diverse metabolic diseases, for example, diabetes and its complications (e.g., diabetic nephropathy, diabetic cardiomyopathy, diabetic myocardial ischemia/reperfusion injury and atherosclerosis [AS]), metabolic bone disease and adrenal injury. However, the specific physiopathological mechanism and precise therapeutic effect is still not clear. In this review, we summarized recent advances about the development of ferroptosis, focused on its potential character as the therapeutic target in metabolic diseases, and put forward our insights on this topic, largely to offer some help to forecast further directions.

Natural and synthetic antioxidants targeting cardiac oxidative stress and redox signaling in cardiometabolic diseases

Cardiometabolic diseases (CMDs) are metabolic diseases (e.g., obesity, diabetes, atherosclerosis, rare genetic metabolic diseases, etc.) associated with cardiac pathologies. Pathophysiology of most CMDs involves increased production of reactive oxygen species and impaired antioxidant defense systems, resulting in cardiac oxidative stress (OxS). To alleviate OxS, various antioxidants have been investigated in several diseases with conflicting results. Here we review the effect of CMDs on cardiac redox homeostasis, the role of OxS in cardiac pathologies, as well as experimental and clinical data on the therapeutic potential of natural antioxidants (including resveratrol, quercetin, curcumin, vitamins A, C, and E, coenzyme Q10, etc.), synthetic antioxidants (including N-acetylcysteine, SOD mimetics, mitoTEMPO, SkQ1, etc.), and promoters of antioxidant enzymes in CMDs. As no antioxidant indicated for the prevention and/or treatment of CMDs has reached the market despite the large number of preclinical and clinical studies, a sizeable translational gap is evident in this field. Thus, we also highlight potential underlying factors that may contribute to the failure of translation of antioxidant therapies in CMDs.

Pharmacological Protection against Ischemia-Reperfusion Injury by Regulating the Nrf2-Keap1-ARE Signaling Pathway

Ischemia/reperfusion (I/R) injury is associated with substantial clinical implications, including a wide range of organs such as the brain, kidneys, lungs, heart, and many others. I/R injury (IRI) occurs due to the tissue injury following the reestablishment of blood supply to ischemic tissues, leading to enhanced aseptic inflammation and stimulation of oxidative stress via reactive oxygen and nitrogen species (ROS/RNS). Since ROS causes membrane lipids’ peroxidation, triggers loss of membrane integrity, denaturation of proteins, DNA damage, and cell death, oxidative stress plays a critical part in I/R pathogenesis. Therefore, ROS regulation could be a promising therapeutic strategy for IRI. In this context, Nrf2 (NF-E2-related factor 2) is a transcription factor that regulates the expression of several factors involved in the cellular defense against oxidative stress and inflammation, including heme oxygenase-1 (HO-1). Numerous studies have shown the potential role of the Nrf2/HO-1 pathway in IRI; thus, we will review the molecular aspects of Nrf2/Kelch-like ECH-associated protein 1 (Keap1)/antioxidant response element (ARE) signaling pathway in I/R, and we will also highlight the recent insights into targeting this pathway as a promising therapeutic strategy for preventing IRI.