Xiaojianzhong decoction attenuates gastric mucosal injury by activating the p62/Keap1/Nrf2 signaling pathway to inhibit ferroptosis

Research progress on the use of traditional Chinese medicine to treat diseases by regulating ferroptosis

Ferroptosis is an emerging form of programmed cell death triggered by iron-dependent lipid peroxidation. It is distinguished from other forms of cell death by its unique morphological changes and characteristic fine-tuned regulatory gene network. Since its pivotal involvement in the pathogenesis and therapeutic interventions of various diseases, such as malignant tumors, cardiovascular and cerebrovascular diseases, and traumatic disorders, has been well-established, ferroptosis has garnered significant attention in contemporary physiological and pathological research. For the advantage of alleviating the clinical symptoms and improving life quality, traditional Chinese medicine (TCM) holds a significant position in the treatment of these ailments. Moreover, increasing studies revealed that TCM compounds and monomers showed evident therapeutic efficacy by regulating ferroptosis via signaling pathways that tightly regulate redox reactions, iron ion homeostasis, lipid peroxidation, and glutathione metabolism. In this paper, we summarized the current knowledge of TCM compounds and monomers in regulating ferroptosis, aiming to provide a comprehensive review of disease management by TCM decoction, Chinese patent medicine, and natural products deriving from TCM through ferroptosis modulation. The formulation composition, chemical structure, and possible targets or mechanisms presented here offer valuable insights into the advancement of TCM exploration.

Baicalin plays a protective role by regulating ferroptosis in multiple diseases

Ferroptosis is a new kind of cell death discovered in recent years, usually accompanied by a large number of lipid peroxidation and iron accumulation in the process of cell death. Ferroptosis has been proven to play an important role in various diseases, including ischemic reperfusion injury, cancer, and neurodegeneration. Therefore, the regulation of ferroptosis will have a vital impact on the occurrence and development of diseases. Baicalin is a flavonoid compound extracted and isolated from the dried roots of Scutellaria baicalensis Georgi, a plant in the family Lamiaceae. It has various biological activities such as antioxidant, anti-proliferative, anti-inflammatory, anti-thrombotic, and regulates apoptosis and ferroptosis. Recently, increasing evidence indicates that baicalin regulation of ferroptosis is involved in multiple diseases. However, the relevant mechanisms are not yet fully understood. Here, we summarized the role of baicalin regulation of ferroptosis in different kinds of diseases, and conducted an in-depth analysis of the relevant mechanisms, hoping to provide the theoretical references for future related researches.

The effect of 254 nm ultraviolet C promoting ethanol-induced gastric injury healing - A potential physical factor therapy

BACKGROUND

Gastritis, gastric ulcer, and gastric bleeding are associated with gastric mucosal injury. Chemical drugs are the current mainstream method, but the limitations are also increasingly apparent. Accumulative basic and clinical evidence has confirmed that ultraviolet C (UVC) has a significant effect on improving superficial infectious inflammation, promoting the healing of injured wounds, mucous membranes and ulcers, and killing microorganisms. It is possible to explore a new treatment method by introducing UVC light into the stomach to treat the damaged gastric mucosa.

OBJECTIVE

This study evaluated the efficacy of introducing 254 nm UVC into the stomach by the self-made light guide at different doses and time to promote the healing of injured gastric mucosa, and explored the potential mechanism underling the treatment effect.

METHODS

The rat model of gastric mucosal injury induced by ethanol was intervened by UVC with different radiation doses. The ulcer index, histopathology, CAT, SOD, MDA, NO, TNF-α, IL-6 and EGF in gastric mucosa and serum were evaluated. In addition, the expression of ASC, IL-1β and Caspase-1 in gastric tissue was evaluated.

RESULTS

UVC significantly improved the histopathological condition of damaged gastric mucosa and reduce the ulcer index. UVC reduced the levels of TNF-α and IL-6, increase the level of EGF in serum. It also significantly increased the levels of SOD, CAT and NO, and reduced the levels of MDA in serum and gastric tissue. The expression of ASC, IL-1β and Caspase-1 in gastric mucosa was significantly inhibited, and it showed a significant dose-dependent trend with UVC irradiation dose.

CONCLUSION

Intragastric irradiation of 254 nm UVC can effectively promote the repair of damaged gastric mucosa by inhibiting inflammatory factors, activating antioxidant system and inhibiting the apoptosis-related proteins, which may provide a promising way for clinical application of physical factors in the treatment of gastric mucosal injury. However, whether the technology can be finally applied to clinical practice requires more rigorous safety and effectiveness studies.

A Mechanism Study on the Antioxidant Pathway of Keap1-Nrf2- ARE Inhibiting Ferroptosis in Dopaminergic Neurons

BACKGROUND

The pathology of Parkinson's disease (PD) indicates that iron deposition exists in dopaminergic neurons, which may be related to the death of cellular lipid iron peroxide. The extracellular autophagy adaptor SQSTM1(p62) of dopamine (DA) neurons can activate the intracellular Keap1-Nrf2-ARE signaling pathway to inhibit ferroptosis, which has a protective effect on DA neurons.

OBJECTIVE

The objective of this study was to investigate the protective mechanism of the Keap1- Nrf2-ARE antioxidant pathway against iron death in dopaminergic neurons.

METHODS

The experiment was divided into a control group (Control group), 1-methyl-4- phenylpyridiniumion control group (MPP+ Control group), p62 overexpression group (MPP+OVp62), and p62 overexpression no-load group (MPP+ OV-P62-NC). The inhibitors brusatol and ZnPP inhibited the activation of NF-E2-related factor 2(Nrf2) and Heme oxygenase-1(HO-1), respectively, and were divided into brusatol group (MPP+OV-p62+brusatol) and ZnPP group (MPP+OV-p62+ZnPP). RT-qPCR was used to detect transfection efficiency, and Cell Counting Kit-8 (CCK8) was used to detect cell activity. FerroOrange, 2,7-Dichlorodihydrofluorescein diacetate (DCFH-DA), and Liperfluo probes were used to detect intracellular iron, reactive oxygen species (ROS), and lipid peroxidation (LPO) levels. Western Blotting detected the levels of Nrf2, HO-1, Kelch-like ECH-associated protein1 (Keap1), and their downstream Glutathione peroxidase 4(GPX4) and Acyl-CoA synthetase long-chain family member 4(ACSL4). The levels of LGlutathione (GSH) and Malondialdehyde (MDA) were detected by GSH and MDA kits, and the activation of Keap1-Nrf2-ARE pathway was verified at the cellular level to have an antioxidant protective effect on iron death in dopaminergic neurons.

RESULTS

(1) The results of RT-qPCR showed that compared with the control group, the expression of the p62 gene was significantly increased in the MPP+OV-p62 groups (p = 0.039), and the p62 gene was significantly increased in the brusatol and ZnPP groups, indicating successful transfection (p =0.002; p=0.008). (2) The immunofluorescence probe flow results showed that compared to the normal control group, the contents of three kinds of probes in MPP+ model group were significantly increased (p =0.001; p <0.001; p<0.001), and the contents of three kinds of probes in MPP+OV-p62 group were decreased compared to the MPP+ model group (p =0.004). The results indicated that the levels of iron, ROS, and LPO were increased in the MPP+ group and decreased in the MPP+OV-p62 group. (3) Compared with the control group, the expressions of Nrf2, HO-1, and GPX4 in the MPP+OV-p62 group were increased (p =0.007; p =0.004; p=0.010), and the expressions of Keap1 and ACSL4 in MPP+p62 overexpression group were decreased (p =0.017; p =0.005). Compared with the MPP+ control group, Nrf2 and GPX4 were increased in the MPP+OV-p62 group, and ACSL4 was decreased in the MPP+OV-p62 group (p =0.041; p <0.001; p <0.001). The results of the GSH and MDA kit showed that compared with the normal control group, the content of GSH in the MPP+ control group was decreased (p < 0.01), and the content of MDA was increased (p < 0.01). Compared with the MPP+ model group, GSH content was increased (P = 0.003), and MDA content was decreased in the MPP+OV-p62 group (p < 0.001). Nrf2, HO-1, and GPX4 increased in the MPP+p62 overexpression group but decreased in the brusatol group and ZnPP group (p < 0.001).

CONCLUSION

Based on the transfection of P62 plasmid, it was found that P62 plasmid can inhibit the lipid peroxidation of iron death in dopaminergic nerve cells by activating the Nrf2 signaling pathway, thus playing a protective role in dopaminergic nerve cells.

Exploring Xiaojianzhong decoction's potential in gastric cancer treatment: Integrative insights and experimental validation

Gastric cancer (GC) remains a formidable global health concern with significant morbidity and mortality rates, despite the fact that numerous advances have been made to improve conventional therapies. Xiaojianzhong decoction (XJZ), a traditional Chinese medicine, has garnered academic attention as a multicomponent, multitarget approach to managing GC. The present editorial explores the potential of XJZ in the treatment of GC through a comprehensive analysis of network pharmacology and experimental validation. Network pharmacology was used to identify key molecular targets of XJZ, including interleukin 6, prostaglandin-endoperoxide synthase 2, and matrix metalloproteinase 9, and in vitro experiments were used to confirm the efficacy of XJZ in inhibiting cell proliferation, inducing apoptosis, and modulating gene expression associated with GC progression. This editorial highlights XJZ as a promising therapeutic strategy for GC and indicates a need for further clinical exploration and validation of its efficacy.

Decoding the power of saponins in ferroptosis regulation and disease intervention: a review

OBJECTIVES

This review endeavors to elucidate the complex interplay underlying diseases associated with ferroptosis and to delineate the multifaceted mechanisms by which triterpenoid and steroidal saponins modulate this form of cell death.

METHODS

A meticulous examination of the literature was undertaken, drawing from an array of databases including Web of Science, PubMed, and Wiley Library, with a focus on the keywords "ferroptosis," "saponin," "cancer," "inflammation," "natural products," and "signaling pathways."

KEY FINDINGS

Ferroptosis represents a distinctive mode of cell death that holds considerable promise for the development of innovative therapeutic strategies targeting a wide range of diseases, especially cancer and inflammatory disorders. This review reveals the nuanced interactions between saponins and critical signaling pathways, including system Xc--GSH-GPX4, Nrf2, p53, and mTOR. These interactions highlight the dual capacity of saponins to modulate ferroptosis, thereby offering fresh perspectives for therapeutic intervention.

CONCLUSIONS

The insights garnered from this review significantly advance our comprehension of the dynamic relationship between saponins and ferroptosis. By shedding light on these mechanisms, this work sets the stage for leveraging these insights in the creation of pioneering approaches to disease treatment, marking a significant stride in the evolution of therapeutic modalities.

Gastroduodenal injury and repair mechanisms

PURPOSE OF REVIEW

Although the mucosal barrier serves as a primary interface between the environment and host, little is known about the repair of acute, superficial lesions or deeper, persistent lesions that if not healed, can be the site of increased permeability to luminal antigens, inflammation, and/or neoplasia development.

RECENT FINDINGS

Studies on acute superficial lesions have been sparse in the past year, with more focus given to novel mechanisms of mucosal protection, and the way in which mature epithelial cells or committed stem cells dedifferentiate, reprogram, proliferate, and then regenerate the gastroduodenal mucosa after injury. For this, adenoviral therapy showed organ specific targeting with mRNA and protein expression of effectors to protect against mucosal injury and ulceration. A large database of plant-based agents known to protect against injury and ulceration was published, along with studies using plant-based compounds delivered with alginates, polysaccharide/gel floating rafts, or incorporated into nanoparticles or green carbon dots to improve targeting and retention at the ulcerated lesion. With RNA technology developing rapidly, particularly single-cell RNA sequencing, important and novel data was forthcoming on mucosal regeneration. In particular, the role of interleukin-17 hub proteins in mucosal healing was highlighted. The presence and role of injury reserve cells was determined, as was the composition of ligand gradients for cell differentiation in both stomach and duodenum. The role of amphiregulin in parietal cell differentiation from lineage-restricted stem cells and the Yap1 gene signature in metaplasia vs. healing ulcers were of particular importance. Additionally, studies unveiled the important role of mesenchymal stromal cells in differentiation and repair mechanisms, in Muse cells as an exciting new therapy for mucosal repair after injury, and the role of sympathetic neurons in activating the immune system to regulate mucosal repair mechanisms.

SUMMARY

Recent studies highlight novel mechanisms that promote mucosal regeneration after injury of the gastroduodenal mucosa.

Nrf2-mediated ferroptosis inhibition: a novel approach for managing inflammatory diseases

Inflammatory diseases, including psoriasis, atherosclerosis, rheumatoid arthritis, and ulcerative colitis, are characterized by persistent inflammation. Moreover, the existing treatments for inflammatory diseases only provide temporary relief by controlling symptoms, and treatments of unstable and expensive. Therefore, new therapeutic solutions are urgently needed to address the underlying causes or symptoms of inflammatory diseases. Inflammation frequently coincides with a high level of (reactive oxygen species) ROS activation, serving as a fundamental element in numerous physiological and pathological phenotypes that can result in serious harm to the organism. Given its pivotal role in inflammation, oxidative stress, and ferroptosis, ROS represents a focal node for investigating the (nuclear factor E2-related factor 2) Nrf2 pathway and ferroptosis, both of which are intricately linked to ROS. Ferroptosis is mainly triggered by oxidative stress and involves iron-dependent lipid peroxidation. The transcription factor Nrf2 targets several genes within the ferroptosis pathway. Recent studies have shown that Nrf2 plays a significant role in three key ferroptosis-related routes, including the synthesis and metabolism of glutathione/glutathione peroxidase 4, iron metabolism, and lipid processes. As a result, ferroptosis-related treatments for inflammatory diseases have attracted much attention. Moreover, drugs targeting Nrf2 can be used to manage inflammatory conditions. This review aimed to assess ferroptosis regulation mechanism and the role of Nrf2 in ferroptosis inhibition. Therefore, this review article may provide the basis for more research regarding the treatment of inflammatory diseases through Nrf2-inhibited ferroptosis.

Network pharmacology study and in vitro experimental validation of Xiaojianzhong decoction against gastric cancer

BACKGROUND

Cancer is one of the most serious threats to human health worldwide. Conventional treatments such as surgery and chemotherapy are associated with some drawbacks. In recent years, traditional Chinese medicine treatment has been increasingly advocated by patients and attracted attention from clinicians, and has become an indispensable part of the comprehensive treatment for gastric cancer.

AIM

To investigate the mechanism of Xiaojianzhong decoction (XJZ) in the treatment of gastric cancer (GC) by utilizing network pharmacology and experimental validation, so as to provide a theoretical basis for later experimental research.

METHODS

We analyzed the mechanism and targets of XJZ in the treatment of GC through network pharmacology and bioinformatics. Subsequently, we verified the impact of XJZ treatment on the proliferative ability of GC cells through CCK-8, apoptosis, cell cycle, and clone formation assays. Additionally, we performed Western blot analysis and real-time quantitative PCR to assess the protein and mRNA expression of the core proteins.

RESULTS

XJZ mainly regulates IL6, PTGS2, CCL2, MMP9, MMP2, HMOX1, and other target genes and pathways in cancer to treat GC. The inhibition of cell viability, the increase of apoptosis, the blockage of the cell cycle at the G0/G1 phase, and the inhibition of the ability of cell clone formation were observed in AGS and HGC-27 cells after XJZ treatment. In addition, XJZ induced a decrease in the mRNA expression of IL6, PTGS2, MMP9, MMP2, and CCL2, and an increase in the mRNA expression of HOMX1. XJZ significantly inhibited the expression of IL6, PTGS2, MMP9, MMP2, and CCL2 proteins and promoted the expression of the heme oxygenase-1 protein.

CONCLUSION

XJZ exerts therapeutic effects against GC through multiple components, multiple targets, and multiple pathways. Our findings provide a new idea and scientific basis for further research on the molecular mechanisms underlying the therapeutic effects of XJZ in the treatment of GC.

Cepharanthine triggers ferroptosis through inhibition of NRF2 for robust ER stress against lung cancer

BACKGROUND

Severe endoplasmic reticulum (ER) stress elicits apoptosis to suppress lung cancer. Our previous research identified that Cepharanthine (CEP), a kind of phytomedicine, possessed powerful anti-cancer efficacy, for which the underlying mechanism was still uncovered. Herein, we investigated how CEP induced ER stress and worked against lung cancer.

METHODS

The differential expression genes (DEGs) and enrichment were detected by RNA-sequence. The affinity of CEP and NRF2 was analyzed by cellular thermal shift assay (CETSA) and molecular docking. The function assay of lung cancer cells was measured by western blots, flow cytometry, immunofluorescence staining, and ferroptosis inhibitors.

RESULTS

CEP treatment enriched DEGs in ferroptosis and ER stress. Further analysis demonstrated the target was NRF2. In vitro and in vivo experiments showed that CEP induced obvious ferroptosis, as characterized by the elevated iron ions, ROS, COX-2 expression, down-regulation of GPX4, and atrophic mitochondria. Moreover, enhanced Grp78, CHOP expression, β-amyloid mass, and disappearing parallel stacked structures of ER were observed in CEP group, suggesting ER stress was aroused. CEP exhibited excellent anti-lung cancer efficacy, as evidenced by the increased apoptosis, reduced proliferation, diminished cell stemness, and prominent inhibition of tumor grafts in animal models. Furthermore, the addition of ferroptosis inhibitors weakened CEP-induced ER stress and apoptosis.

CONCLUSION

In summary, our findings proved CEP drives ferroptosis through inhibition of NRF2 for induction of robust ER stress, thereby leading to apoptosis and attenuated stemness of lung cancer cells. The current work presents a novel mechanism for the anti-tumor efficacy of the natural compound CEP.

Protective effects of the bioactive peptide from maggots against skin flap ischemia‒reperfusion injury in rats

Ischemia‒reperfusion (I/R) injury is a frequently observed complication after flap surgery, and it affects skin flap survival and patient prognosis. Currently, there are no proven safe and effective treatment options to treat skin flap I/R injury. Herein, the potential efficacies of the bioactive peptide from maggots (BPM), as well as its underlying mechanisms, were explored in a rat model of skin flap I/R injury and LPS- or H2O2-elicited RAW 264.7 cells. We demonstrated that BPM significantly ameliorated the area of flap survival, and histological changes in skin tissue in vivo. Furthermore, BPM could markedly restore or enhance Nrf2 and HO-1 levels, and suppress the expression of pro-inflammatory cytokines, including TLR4, p-IκB, NFκB p65, p-p65, IL-6, and TNF-α in I/R-injured skin flaps. In addition, BPM treatment exhibited excellent biocompatibility with an adequate safety profile, while it exhibited superior ROS-scavenging ability and the upregulation of antioxidant enzymes in vitro. Mechanistically, the above benefits related to BPM involved the activation of Nrf2/HO-1 and suppression of TLR4/NF-κB pathway. Taken together, this study may provide a scientific basis for the potential therapeutic effect of BPM in the prevention of skin flap I/R injury and other related diseases.

The role of metal ions in the occurrence, progression, drug resistance, and biological characteristics of gastric cancer

Metal ions exert pivotal functions within the human body, encompassing essential roles in upholding cell structure, gene expression regulation, and catalytic enzyme activity. Additionally, they significantly influence various pathways implicated in divergent mechanisms of cell death. Among the prevailing malignant tumors of the digestive tract worldwide, gastric cancer stands prominent, exhibiting persistent high mortality rates. A compelling body of evidence reveals conspicuous ion irregularities in tumor tissues, encompassing gastric cancer. Notably, metal ions have been observed to elicit distinct contributions to the progression, drug resistance, and biological attributes of gastric cancer. This review consolidates pertinent literature on the involvement of metal ions in the etiology and advancement of gastric cancer. Particular attention is directed towards metal ions, namely, Na, K, Mg, Ca, Fe, Cu, Zn, and Mn, elucidating their roles in the initiation and progression of gastric cancer, cellular demise processes, drug resistance phenomena, and therapeutic approaches.

Mechanism of Xiaojianzhong decoction in alleviating aspirin-induced gastric mucosal injury revealed by transcriptomics and metabolomics

ETHNOPHARMACOLOGICAL RELEVANCE

Aspirin, as a first-line drug for the treatment of cardiovascular diseases, currently has high clinical usage. However, reports of aspirin-induced gastric mucosal injury are increasing. Xiaojianzhong decoction (XJZD), a classic traditional Chinese medicine formula, has been shown to alleviate gastric mucosal injury, although its potential mechanism of action requires further study.

AIM OF THE STUDY

This study aimed to explore the effect and mechanism of XJZD in preventing aspirin-induced gastric mucosal injury.

MATERIALS AND METHODS

Aspirin was used to induce damage in the morning, while XJZD was applied as an intervention in the afternoon. The compounds in the XJZD were analyzed by means of both high-performance liquid chromatography and ultra-performance liquid chromatography-tandem mass spectrometry. The overall condition of the aspirin-related gastric mucosal injury was evaluated. The expressions of inflammatory factors and tight-junction-related proteins and apoptosis were observed via immunohistochemistry and immunofluorescence. The expression levels of the apoptosis-related proteins were detected using Western blot. Transcriptomics was used to perform the integrative analysis of gastric tissues, which was then validated. Molecular dynamics was used to explore the interaction of key compounds within the XJZD with relevant targets. Finally, non-targeted metabolomics was used to observe any metabolic changes and construct a network between the differentially expressed genes and the differential metabolites to elucidate their potential relationship.

RESULTS

XJZD can alleviate inflammation response, maintain the gastric mucosal barrier's integrity, reduce apoptosis and necroptosis levels, and promote the proliferation and repair of gastric mucosal tissues. Its mechanism of action may be related to the regulation of TNF-α signaling. Furthermore, molecular docking showed that the cinnamaldehyde within XJZD played an important role in its effects. In addition, XJZD can correct metabolic disorders, mainly regulating amino acid metabolism pathways. Moreover, six differential genes (Cyp1a2, Cyp1a1, Pla2g4c, etc.) were determined to alleviate both gastric mucosal injury and inflammation by regulating arachidonic acid metabolism, Tryptophan metabolism, etc. CONCLUSIONS: This study is the first to report that XJZD can inhibit necroptosis and gastric mucosal injury induced by aspirin, thereby revealing the complex mechanism of XJZD in relation to alleviating gastric mucosal injury from multiple levels and perspectives.

Anise (Pimpinella anisum L.) attenuates azoxymethane-induced colorectal cancer by antioxidant, anti-inflammatory, and anti-apoptotic pathways in rats

Herbal medicine is one of the most common fields explored for combating colon cancers, and Pimpinella anisum L. seeds (PAS) have been utilized widely as medicinal agents because of their increased essential oil (trans-anethole) contents. In this essence, our study investigates the toxic effect and chemoprotective potentials of PAS against azoxymethane (AOM)-induced colon cancer in rats. The toxicity trial for PAS conducted by clustering fifteen rats into three groups (five rats each): A, normal control had 10% Tween 20; B, ingested with 2 g/kg PAS; and C, supplemented with 4 g/kg PAS. The in vivo cancer trial was performed by using 30 rats (Sprague-Dawley) that were randomly adapted in five steel cages (six rats each): group A, normal controls received two subcutaneous injections of normal saline 0.09% and ingested orally 10% Tween 20; groups B-E, rats received two injections of 15 mg/kg of azoxymethane (AOM) subcutaneously in 2 weeks and treated orally with 10% Tween 20 (group B) or intraperitoneal injection of 5-fluorouracil (35 mg/kg) (group C), or orally given 200 mg/kg PAS (group D) and 400 mg/kg PAS (group E) for 8 weeks. After the scarification of rats, the colon tissues were dissected for gross and histopathological evaluations. The acute toxicity trial showed the absence of any toxic signs in rats even after 14 days of ingesting 4 g/kg of PAS. The chemoprotective experiment revealed significant inhibitory potentials (65.93%) of PAS (400 mg/kg) against aberrant crypto foci incidence that could be correlated with its positive modulation of the immunohistochemically proteins represented by a significant up-regulation of the Bax protein and a decrease of the Bcl-2 protein expressions in colon tissues. Furthermore, PAS-treated rats had notably lower oxidative stress in colon tissues evidenced by decreased MDA levels and increased antiradical defense enzymes (SOD, CAT, and GPx). The outcomes suggest 400 mg/kg PAS as a viable additive for the development of potential pharmaceuticals against colorectal cancer.

The Gastroprotective Effect of Walnut Peptides: Mechanisms and Impact on Ethanol-Induced Acute Gastric Mucosal Injury in Mice

The objective of this research was to explore the protective impact of walnut peptides (WP) against ethanol-induced acute gastric mucosal injury in mice and to investigate the underlying defense mechanisms. Sixty male BALB-c mice were divided into five groups, and they were orally administered distilled water, walnut peptides (200 and 400 mg/kg bw), and omeprazole (20 mg/kg bw) for 24 days. Acute gastric mucosal injury was then induced with 75% ethanol in all groups of mice except the blank control group. Walnut peptides had significant protective and restorative effects on tissue indices of ethanol-induced gastric mucosal damage, with potential gastric anti-ulcer effects. Walnut peptides significantly inhibited the excessive accumulation of alanine aminotransferase (ALT), aspartate transferase (AST), and malondialdehyde (MDA), while promoting the expression of reduced glutathione (GSH), total antioxidant capacity (T-AOC), glutathione disulfide (GSSG), and mouse epidermal growth factor (EGF). Furthermore, the Western blot analysis results revealed that walnut peptides significantly upregulated the expression of HO-1 and NQO1 proteins in the Nrf2 signaling pathway. The defensive impact of walnut peptides on the gastric mucosa may be achieved by mitigating the excessive generation of lipid peroxides and by boosting cellular antioxidant activity.

Pathophysiology updates: gastroduodenal injury and repair mechanisms

PURPOSE OF REVIEW

Although the mucosal barrier serves as a primary interface between the environment and host, little is known about the repair of acute, superficial lesions or deeper, persistent lesions that if not healed, can be the site of increased permeability to luminal antigens, inflammation, and/or neoplasia development.

RECENT FINDINGS

Recent studies on acute superficial lesions have focused on calcium signaling and focal adhesion kinase, which regulate cell migration and controlled matrix adhesion during restitution. Microfluidic organ-on-a-chip and gut-on-a-chip models continued in development to support reductionist studies of epithelial-bacterial and/or epithelial-immune cell interactions during mucosal barrier disruption. In fact, these models may allow personalized medicine studies in the future using patient-derived cells to evaluate injury and repair mechanisms. Work done in the past year evaluated the safety and efficacy of acid blocking drugs on ulcer healing, with new animal studies providing evidence that each drug affects the microbiome in a different way that can be correlated with its efficacy in ulcer healing. Lastly, work to understand the way in which mature epithelial cells or committed stem cells dedifferentiate, reprogram, proliferate, and then regenerate the gastroduodenal mucosa after injury was a major focus of studies in the past year.

SUMMARY

Recent studies highlight novel mechanisms that promote restitution and mucosal regeneration after injury of the gastroduodenal mucosa.

Paraquat-induced ferroptosis suppression via NRF2 expression regulation

Paraquat (PQ) is an environmentally friendly and efficient herbicide, but PQ misuse or intentional self-use can cause death through multiple organ damage and can cause acute lung injury. Existing clinical treatments alleviate symptoms but do not significantly improve the mortality rate. Ferroptosis is a type of necrosis that presents in a manner very similar to the cell damage induced by high doses of PQ, but the role of ferroptosis in paraquat-induced lung injury remains unclear. In this study, we aimed to explore the role of ferroptosis in PQ-induced A549 cell injury and identify the potential mechanisms and critical sites of protection against PQ-induced A549 injury by ferroptosis inhibitors. We found that the ferroptosis inhibitors Ferr-1 and Lip-1 inhibit ferroptosis by attenuating oxidative stress through the upregulation of NRF2 gene expression. The protective role of the ferroptosis inhibitor Dfo was most evident in paraquat-induced cell injury. Dfo inhibited ferroptosis by iron chelation and promoted NRF2 protein level reduction. NRF2 attenuated PQ-induced ferroptosis in A549 cells, mainly through the upregulation of SLC40A1 to encourage the movement of iron to the extracellular side to alleviate iron overload, and the upregulation of SLC7A11 to promote the expression of GPX4 to inhibit lipid peroxidation.

NRF2, a Superstar of Ferroptosis

Ferroptosis is an iron-dependent and lipid peroxidation-driven cell death cascade, occurring when there is an imbalance of redox homeostasis in the cell. Nuclear factor erythroid 2-related factor 2 (NFE2L2, also known as NRF2) is key for cellular antioxidant responses, which promotes downstream genes transcription by binding to their antioxidant response elements (AREs). Numerous studies suggest that NRF2 assumes an extremely important role in the regulation of ferroptosis, for its various functions in iron, lipid, and amino acid metabolism, and so on. Many pathological states are relevant to ferroptosis. Abnormal suppression of ferroptosis is found in many cases of cancer, promoting their progression and metastasis. While during tissue damages, ferroptosis is recurrently promoted, resulting in a large number of cell deaths and even dysfunctions of the corresponding organs. Therefore, targeting NRF2-related signaling pathways, to induce or inhibit ferroptosis, has become a great potential therapy for combating cancers, as well as preventing neurodegenerative and ischemic diseases. In this review, a brief overview of the research process of ferroptosis over the past decade will be presented. In particular, the mechanisms of ferroptosis and a focus on the regulation of ferroptosis by NRF2 will be discussed. Finally, the review will briefly list some clinical applications of targeting the NRF2 signaling pathway in the treatment of diseases.

Interaction mechanisms between autophagy and ferroptosis: Potential role in colorectal cancer

Colorectal cancer (CRC) is a common malignancy that has the second highest incidence and mortality rate. Although there are many personalized treatment options for CRC, the therapeutic effects are ultimately limited by drug resistance. Studies have aimed to block the initiation and progression of CRC by inducing cell death to overcome this obstacle. Substantial evidence has indicated that both autophagy and ferroptosis play important regulatory roles in CRC. Autophagy, a lysosome-dependent process by which cellular proteins and organelles are degraded, is the basic mechanism for maintaining cell homeostasis. The duality and complexity of autophagy in cancer therapy is a hot topic of discussion. Ferroptosis, a regulated cell death pathway, is associated with iron accumulation-induced lipid peroxidation. The activation of ferroptosis can suppress CRC proliferation, invasion and drug resistance. Furthermore, recent studies have suggested an interaction between autophagy and ferroptosis. Autophagy can selectively degrade certain cellular contents to provide raw materials for ferroptosis, ultimately achieving antitumor and anti-drug resistance. Therefore, exploring the interaction between autophagy and ferroptosis could reveal novel ideas for the treatment of CRC. In this review, we describe the mechanisms of autophagy and ferroptosis, focusing on their roles in CRC and the crosstalk between them.

Bile acid metabolism involved into the therapeutic action of Xiaojianzhong Tang via gut microbiota to treat chronic atrophic gastritis in rats

BACKGROUND

As a classical traditional Chinese medicine (TCM), Xiaojianzhong Tang (XJZ) is effective in treating chronic atrophic gastritis (CAG). However, the pharmacological mechanism of XJZ has not been fully explained.

PURPOSE

The purpose of this study was to investigate the mechanism of XJZ against CAG rats via gut microbiome using a multi-omics approach.

METHODS

The rat cecal contents were analyzed through the integration of an untargeted metabolomic approach based on ultra-high performance liquid chromatography coupled with the quadrupole-time of flight mass spectrometry (UHPLC-QTOF-MS) and 16S rRNA gene sequencing. Finally, the interaction of differential metabolites with bile acid (BA)-related targets was verified by molecular docking.

RESULTS

A new strategy was adopted to screen out the differential metabolites based on the comprehensive evaluation of VIP, |log2(FC)|, -ln(p-value) and ǀp(corr)ǀ. As results, XJZ showed favor regulations on the screened metabolites, cholic acid, deoxycholic acid, glycoursodeoxycholic acid, taurochenodesoxycholic acid, docosahexaenoic acid and L-isoleucine. The 16S rRNA gene sequencing analysis showed that XJZ could regulate gut microbiota disturbances in CAG rats, especially bile acid (BA) metabolism-related bacteria (Butyricimonas, Desulfovibrio, Bacteroides, Parabacteroides, Acetobacter and Alistipes). Molecular docking further showed that the differential metabolites regulated by XJZ had a good docking effect on BA-related targets.

CONCLUSION

The current work indicated that XJZ's therapeutic action was strongly linked to BA-related microorganisms and metabolic processes. These findings provided new insights into the effects of XJZ for the treatment of CAG.

Cobalt chloride has beneficial effects across species through a hormetic mechanism

Severe oxygen and iron deficiencies have evolutionarily conserved detrimental effects, leading to pathologies in mammals and developmental arrest as well as neuromuscular degeneration in the nematode Caenorhabditis elegans. Yet, similar to the beneficial effects of mild hypoxia, non-toxic levels of iron depletion, achieved with the iron chelator bipyridine or through frataxin silencing, extend C. elegans lifespan through hypoxia-like induction of mitophagy. While the positive health outcomes of hypoxia preconditioning are evident, its practical application is rather challenging. Here, we thus test the potential beneficial effects of non-toxic, preconditioning interventions acting on iron instead of oxygen availability. We find that limiting iron availability through the iron competing agent cobalt chloride has evolutionarily conserved dose-dependent beneficial effects: while high doses of cobalt chloride have toxic effects in mammalian cells, iPS-derived neurospheres, and in C. elegans, sub-lethal doses protect against hypoxia- or cobalt chloride-induced death in mammalian cells and extend lifespan and delay age-associated neuromuscular alterations in C. elegans. The beneficial effects of cobalt chloride are accompanied by the activation of protective mitochondrial stress response pathways.