Galangin Attenuates Myocardial Ischemic Reperfusion-Induced Ferroptosis by Targeting Nrf2/Gpx4 Signaling Pathway

Nrf2 mediated signaling axis in heart failure: Potential pharmacological receptor

Heart failure (HF) has emerged as the most pressing health concerns globally, and extant clinical therapies are accompanied by side effects and patients have a high burden of financial. The protein products of nuclear factor erythroid 2-related factor 2 (Nrf2) target genes have a variety of cardioprotective effects, including antioxidant, metabolic functions and anti-inflammatory. By evaluating established preclinical and clinical research in HF to date, we explored the potential of Nrf2 to exert unique cardioprotective functions as a novel therapeutic receptor for HF. In this review, we generalize the progression, structure, and function of Nrf2 research in the cardiovascular system. The mechanism of action of Nrf2 involved in HF as well as agonists of Nrf2 in natural compounds are summarized. Additionally, we discuss the challenges and implications for future clinical translation and application of pharmacology targeting Nrf2. It's critical to developing new drugs for HF.

PEDF and 34-mer peptide inhibit cardiac microvascular endothelial cell ferroptosis via Nrf2/HO-1 signalling in myocardial ischemia-reperfusion injury

Myocardial ischemia-reperfusion injury (MIRI) represents a critical pathology in acute myocardial infarction (AMI), which is characterized by high mortality and morbidity. Cardiac microvascular dysfunction contributes to MIRI, potentially culminating in heart failure (HF). Pigment epithelium-derived factor (PEDF), which belongs to the non-inhibitory serpin family, exhibits several physiological effects, including anti-angiogenesis, anti-inflammatory and antioxidant properties. Our study aims to explore the impact of PEDF and its functional peptide 34-mer on both cardiac microvascular perfusion in MIRI rats and human cardiac microvascular endothelial cells (HCMECs) injury under hypoxia reoxygenation (HR). It has been shown that MIRI is accompanied by ferroptosis in HCMECs. Furthermore, we investigated the effect of PEDF and its 34-mer, particularly regarding the Nrf2/HO-1 signalling pathway. Our results demonstrated that PEDF 34-mer significantly ameliorated cardiac microvascular dysfunction following MIRI. Additionally, they exhibited a notable suppression of ferroptosis in HCMECs, and these effects were mediated through activation of Nrf2/HO-1 signalling. These findings highlight the therapeutic potential of PEDF and 34-mer in alleviating microvascular dysfunction and MIRI. By enhancing cardiac microvascular perfusion and mitigating endothelial ferroptosis, PEDF and its derivative peptide represent promising candidates for the treatment of AMI.

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

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

Propolis as an autophagy modulator in relation to its roles in redox balance and inflammation regulation

Autophagy is a degradation process that is evolutionarily conserved and is essential in maintaining cellular and physiological homeostasis through lysosomal removal and elimination of damaged peptides, proteins and cellular organelles. The dysregulation of autophagy is implicated in various diseases and disorders, including cancers, infection-related, and metabolic syndrome-related diseases. Propolis has been demonstrated in various studies including many human clinical trials to have antimicrobial, antioxidant, anti-inflammatory, immune-modulator, neuro-protective, and anti-cancer. Nevertheless, the autophagy modulation properties of propolis have not been extensively studied and explored. The role of propolis and its bioactive compounds in modulating cellular autophagy is possibly due to their dual role in redox balance and inflammation. The present review attempts to discuss the activities of propolis as an autophagy modulator in biological models in relation to various diseases/disorders which has implications in the development of propolis-based nutraceuticals, functional foods, and complementary therapies.

Herbal medicines provide regulation against iron overload in cardiovascular diseases: Informing future applications

ETHNOPHARMACOLOGICAL RELEVANCE

Iron is an essential micronutrient for maintaining physiological activities, especially for highly active cardiomyocytes. Inappropriate iron overload or deficiency has a significant impact on the incidence and severity of cardiovascular diseases (CVD). Iron overload exerts potentially deleterious effects on doxorubicin (DOX) cardiomyopathy, atherosclerosis, and myocardial ischemia-reperfusion injury (MI/RI) by participating in lipid peroxides production. Notably, iron overload-associated cell death has been defined as a possible mechanism for ferroptosis. At present, some traditional herbal medicines and extracts have been included in the study of regulating iron overload and the subsequent therapeutic effect on CVD.

AIM OF THE STUDY

To give an outline of iron metabolism and ferroptosis in cardiomyocytes and to focus on herbal medicines and extracts to prevent iron overload in CVD.

MATERIALS AND METHODS

Literature information was systematically collected from ScienceDirect, PubMed, Google Scholar, Web of Science, China National Knowledge Infrastructure, WanFang data, as well as classic books and clinical reports.

RESULTS

After understanding the mechanism of iron overload on CVD, this paper reviews the therapeutic function of various herbal medicines in eliminating iron overload in CVD. These include Chinese herbal compound prescriptions (Salvia miltiorrhiza injection, Gegen Qinlian decoction, Tongxinluo, Banxia-Houpu decoction), plant extracts, phenylpropanoids, flavonoids, terpenoids, and polyphenols. Among them, flavonoids are considered to be the most promising compounds because of their prominent iron chelation. Mechanically, these herbal medicines act on the Nrf2 signaling pathway, AMPK signaling pathway, and KAT5/GPX4 signaling pathway, thereby attenuating iron overload and lipid peroxidation in CVD.

CONCLUSION

Our review provides up-to-date information on herbal medicines that exert cardiovascular protective effects by modulating iron overload and ferroptosis. These herbal medicines hold promise as a template for preventing iron overload in CVD.

Analgesic and anti-inflammatory effects of galangin: a potential pathway to inhibit transient receptor potential vanilloid 1 receptor activation

Background

Galangin, commonly employed in traditional Chinese medicine for its diverse medicinal properties, exhibits potential in treating inflammatory pain. Nevertheless, its mechanism of action remains unclear.

Methods

Mice were randomly divided into 4 groups for 7 days: a normal control group, a galangin-treated (25 and 50 mg/kg), and a positive control celecoxib (20 mg/kg). Analgesic and anti-inflammatory effects were evaluated using a hot plate test, acetic acid-induced writhing test, acetic acid-induced vascular permeability test, formalininduced paw licking test, and carrageenan-induced paw swelling test. The interplay between galangin, transient receptor potential vanilloid 1 (TRPV1), NF-κB, COX-2, and TNF-α proteins was evaluated via molecular docking. COX- 2, PGE2, IL-1β, IL-6, and TNF-α levels in serum were measured using ELISA after capsaicin administration (200 nmol/L). TRPV1 expression in the dorsal root ganglion was analyzed by Western blot. The quantities of substance P (SP) and calcitonin gene-related peptide (CGRP) were assessed using qPCR.

Results

Galangin reduced hot plate-induced licking latency, acetic acid-induced contortions, carrageenantriggered foot inflammation, and capillary permeability in mice. It exhibited favorable affinity towards TRPV1, NF- κB, COX-2, and TNF-α, resulting in decreased levels of COX-2, PGE2, IL-1β, IL-6, and TNF-α in serum following capsaicin stimulation. Galangin effectively suppressed the upregulation of TRPV1 protein and associated receptor neuropeptides CGRP and SP mRNA, while concurrently inhibiting the expression of NF-κB, TNF-α, COX-2, and PGE2 mRNA.

Conclusions

Galangin exerts its anti-inflammatory pain effects by inhibiting TRPV1 activation and regulating COX-2, NF-κB/TNF-α expression, providing evidence for the use of galangin in the management of inflammatory pain.

LuQi formula attenuates Cardiomyocyte ferroptosis via activating Nrf2/GPX4 signaling axis in heart failure

BACKGROUND

The terminal stage of all cardiovascular diseases typically culminates in heart failure (HF), with no effective intervention available to halt its progression. LuQi formula (LQF) has been employed in clinical for numerous years to significantly ameliorate cardiac function in HF patients. Nevertheless, the underlying mechanism of LQF's efficacy remains inadequately comprehended. Cardiomyocyte ferroptosis has served as a pathogenic mechanism in HF. The goal of the current experiment was to ascertain whether LQF ameliorates HF by preventing cardiomyocyte ferroptosis and to elucidate the intrinsic mechanism involved.

PURPOSE

This research objective is to investigate the impact and underlying mechanism of LQF attenuating cardiomyocyte ferroptosis in heart failure.

METHODS

Transverse aortic constriction (TAC) was performed to construct the HF mouse model. Neonatal rat cardiomyocytes (NRCMs) were subjected to in vitro experiments. High-performance liquid chromatography (HPLC) identified the bioactive compounds in LQF. Transcriptomic and quantitative proteomic analyses revealed the potential targets of LQF anti-HF. Specifically, histological staining evaluated cardiac hypertrophy and fibrosis. Transmission electron microscopy (TEM) observed mitochondrial morphology. The content of Fe2+, ROS, MDA, GSH, and GSSH was detected using kits. Molecular docking evaluated the binding activities between essential active ingredients of LQF and critical proteins of cardiomyocyte ferroptosis. Mechanistically, the expression levels of Nrf2, Keap1, HO-1, SLC7A11, and GPX4 were evaluated using qPCR, Western blot (WB), or immunohistochemical staining.

RESULTS

The primary nine active ingredients in LQF were detected. Transcriptomic and proteomic analyses demonstrated that LQF may ameliorate HF by preventing cardiomyocyte ferroptosis. Histomorphometric analyses revealed that LQF attenuates myocardial hypertrophy and fibrosis. TEM revealed that LQF diminished mitochondrial shrinkage and increased membrane density in myocardial tissue. Additionally, LQF diminished reactive oxygen species (ROS) generation in cardiomyocytes and suppressed cardiomyocyte ferroptosis. Furthermore, the molecular docking technique revealed that the primary active ingredients of LQF had suitable binding activities with Nrf2, GPX4, and SLC7A11. Western analysis further verified that LQF activated the Nrf2/GPX4 signaling axis. decreased SLC7A11 and HO-1 expression.

CONCLUSIONS

These results demonstrated that LQF prevents cardiomyocyte ferroptosis via activating Nrf2/GPX4 signaling axis and suppressing SLC7A11 and HO-1 expression. Concurrently, it contributed to elucidating the intrinsic mechanism of LQF and provided a scientific rationale for its development as a novel cardiovascular therapeutic drug.