Esculin induces endoplasmic reticulum stress and drives apoptosis and ferroptosis in colorectal cancer via PERK regulating eIF2α/CHOP and Nrf2/HO-1 cascades.

ETHNOPHARMACOLOGICAL RELEVANCE: Cortex fraxini (also known as Qinpi), the bark of Fraxinus rhynchophylla Hance and Fraxinus stylosa Lingelsh, constitutes a crucial component in several traditional Chinese formulas (e.g., Baitouweng Tang, Jinxiao Formula, etc.) and has demonstrated efficacy in alleviating intestinal carbuncle and managing diarrhea. Cortex fraxini has demonstrated commendable anticancer activity in the realm of Chinese ethnopharmacology; nevertheless, the underlying mechanisms against colorectal cancer (CRC) remain elusive. AIM OF THE STUDY: Esculin, an essential bioactive compound derived from cortex fraxini, has recently garnered attention for its ability to impede viability and induce apoptosis in cancer cells. This investigation aims to assess the therapeutic potential of esculin in treating CRC and elucidate the underlying mechanisms. MATERIALS AND METHODS: The impact of esculin on CRC cell viability was assessed using CCK-8 assay, Annexin V/PI staining, and Western blotting. Various cell death inhibitors, along with DCFH-DA, ELISA, biochemical analysis, and Western blotting, were employed to delineate the modes through which esculin induces HCT116 cells death. Inhibitors and siRNA knockdown were utilized to analyze the signaling pathways influenced by esculin. Additionally, an azomethane/dextran sulfate sodium (AOM/DSS)-induced in vivo CRC mouse model was employed to validate esculin's potential in inhibiting tumorigenesis and to elucidate its underlying mechanisms. RESULTS: Esculin significantly suppressed the viability of various CRC cell lines, particularly HCT116 cells. Investigation with diverse cell death inhibitors revealed that esculin-induced cell death was associated with both apoptosis and ferroptosis. Furthermore, esculin treatment triggered cellular lipid peroxidation, as evidenced by elevated levels of malondialdehyde (MDA) and decreased levels of glutathione (GSH), indicative of its propensity to induce ferroptosis in HCT116 cells. Enhanced protein levels of protein kinase R (PKR)-like endoplasmic reticulum kinase (PERK) and p-eIF2α suggested that esculin induced cellular endoplasmic reticulum (ER) stress, subsequently activating the Nrf2/ARE signaling pathway and initiating the transcriptional expression of heme oxygenase (HO)-1. Esculin-induced excessive expression of HO-1 could potentially lead to iron overload in HCT116 cells. Knockdown of Ho-1 significantly attenuated esculin-induced ferroptosis, underscoring HO-1 as a critical mediator of esculin-induced ferroptosis in HCT116 cells. Furthermore, utilizing an AOM/DSS-induced colorectal cancer mouse model, we validated that esculin potentially inhibits the onset and progression of colon cancer by inducing apoptosis and ferroptosis in vivo. CONCLUSIONS: These findings provide comprehensive insights into the dual induction of apoptosis and ferroptosis in HCT116 cells by esculin. The activation of the PERK signaling pathway, along with modulation of downstream eIF2α/CHOP and Nrf2/HO-1 cascades, underscores the mechanistic basis supporting the clinical application of esculin on CRC treatment.

[Essential oil of Cinnamomum camphora mitigates depression-like behavior in mice by regulating Nrf2/HO-1 pathway and inhibiting inflammatory cytokines].

This study aims to investigate the essential oil(EOL) of Cinnamomum camphora regarding its anti-depression effect and mechanism in regulating inflammatory cytokines and the nuclear factor erythroid 2-related factor 2(Nrf2)/heme oxygenase-1(HO-1) pathway. A mouse model of depression was established by intraperitoneal injection of lipopolysaccharide(LPS). Open field, elevated plus maze, and forced swimming tests were carried out to examine mouse behaviors. Western blot and qRT-PCR were employed to determine the expression of proteins and genes in the Nrf2/HO-1 pathway in the hippocampus. The levels of tumor necrosis factor(TNF)-α, interleukin(IL)-6, and IL-1ß in the serum were measured by enzyme-linked immunosorbent assay(ELISA). The changes of apoptosis in mouse brain were detected by Tunel staining. Compared with the blank control group, the model group showed shortened distance travelled and time spent in the central zone and reduced number of entries in the central zone in the open field test. In the elevated plus maze test, the model group showed reduced open arm time(OT%) and open arm entries(OE%). In the force swimming test, the model group showed extended duration of immobility compared with the blank control group. Compared with the model group, the treatment with EOL significantly increased the distance travelled and time spent in the central zone and increased the number of entries in the central zone in the open field test. In addition, EOL significantly increased the OT% and OE% in the elevated plus maze and shor-tened the immobility duration in the forced swimming test. The model group showed lower expression levels of Nrf2 and HO-1 and hig-her levels of TNF-α, IL-6, and IL-1ß than the blank control group. Compared with the model group, the treatment with EOL up-regulated the expression levels of Nrf2 and HO-1 and lowered the levels of TNF-α, IL-6, and IL-1ß. The Tunel staining results showed that the apoptosis rate in the brain tissue of mice decreased significantly after the treatment with EOL. To sum up, EOL can mitigate the depression-like behaviors of mice by up-regulating the expression of Nrf2 and HO-1 and preventing hippocampal inflammatory damage. The findings provide empirical support for the application of EOL and aromatherapy in the treatment of depression.

[Ginsenoside Re regulates mitochondrial biogenesis through Nrf2/HO-1/PGC-1α pathway to reduce hypoxia/reoxygenation injury in H9c2 cells].

This article explored the mechanism by which ginsenoside Re reduces hypoxia/reoxygenation(H/R) injury in H9c2 cells by regulating mitochondrial biogenesis through nuclear factor E2-related factor 2(Nrf2)/heme oxygenase-1(HO-1)/peroxisome prolife-rator-activated receptor gamma coactivator-1α(PGC-1α) pathway. In this study, H9c2 cells were cultured in hypoxia for 4 hours and then reoxygenated for 2 hours to construct a cardiomyocyte H/R injury model. After ginsenoside Re pre-administration intervention, cell activity, superoxide dismutase(SOD) activity, malondialdehyde(MDA) content, intracellular reactive oxygen species(Cyto-ROS), and intramitochondrial reactive oxygen species(Mito-ROS) levels were detected to evaluate the protective effect of ginsenoside Re on H/R injury of H9c2 cells by resisting oxidative stress. Secondly, fluorescent probes were used to detect changes in mitochondrial membrane potential(ΔΨ_m) and mitochondrial membrane permeability open pore(mPTP), and immunofluorescence was used to detect the expression level of TOM20 to study the protective effect of ginsenoside Re on mitochondria. Western blot was further used to detect the protein expression levels of caspase-3, cleaved caspase-3, Cyto C, Nrf2, HO-1, and PGC-1α to explore the specific mechanism by which ginsenoside Re protected mitochondria against oxidative stress and reduced H/R injury. Compared with the model group, ginse-noside Re effectively reduced the H/R injury oxidative stress response of H9c2 cells, increased SOD activity, reduced MDA content, and decreased Cyto-ROS and Mito-ROS levels in cells. Ginsenoside Re showed a good protective effect on mitochondria by increasing ΔΨ_m, reducing mPTP, and increasing TOM20 expression. Further studies showed that ginsenoside Re promoted the expression of Nrf2, HO-1, and PGC-1α proteins, and reduced the activation of the apoptosis-related regulatory factor caspase-3 to cleaved caspase-3 and the expression of Cyto C protein. In summary, ginsenoside Re can significantly reduce I/R injury in H9c2 cells. The specific mechanism is related to the promotion of mitochondrial biogenesis through the Nrf2/HO-1/PGC-1α pathway, thereby increasing the number of mitochondria, improving mitochondrial function, enhancing the ability of cells to resist oxidative stress, and alleviating cell apoptosis.

Antioxidant and Anti-Fatigue Effects of a Standardized Botanical Extract Fraction (HemoHIM) in Forced-Exercised Aged Mice.

HemoHIM is a standardized medicinal herbal preparation consisting of extracts of Angelica gigas Nakai, Cnidium officinale Makino, and Paeonia lactiflora Pallas that possesses immune regulatory activities. This study aimed to research the potential antioxidant effects of HemoHIM and its capacity for reducing fatigue in aged mice subjected to forced exercise. After administering HemoHIM 125 (500 mg/kg orally) for 4 weeks in 8-month-old female C57BL/6 mice (4 groups of 10 mice), various parameters were evaluated. The analyses revealed that HemoHIM enhanced swimming time and grip strength. In addition, it significantly reduced serum lactate levels and increased liver glutathione peroxidase (GPx) levels after exercise challenge. The expression levels of antioxidant enzymes and factors, including nuclear factor erythroid 2-related factor-2 (Nrf-2), heme oxygenase 1, superoxide dismutase, GPx, and glutathione reductase, were significantly higher in liver and muscle tissues of mice treated with HemoHIM. These results indicate that HemoHIM might function as an anti-fatigue and antioxidant agent by modulating the Nrf-2 signaling pathway.

Ginseng-derived nanoparticles alleviate alcohol-induced liver injury by activating the Nrf2/HO-1 signalling pathway and inhibiting the NF-κB signalling pathway in vitro and in vivo.

BACKGROUND: Previous studies have confirmed the antioxidant and anti-inflammatory effects of active ginseng components that protect against liver injury. However, ginseng-derived nanoparticles (GDNPs), low-immunogenicity nanovesicles derived from ginseng, have not been reported to be hepatoprotective. PURPOSE: In this study, we investigated whether GDNPs could attenuate alcohol-induced liver injury in LO2 cells and mice by modulating oxidative stress and inflammatory pathways, thereby advancing the theoretical basis for the development of novel pharmacological treatments. STUDY DESIGN: Alcohol was used to construct in vitro and in vivo models of alcoholic liver injury. To explore the mechanisms by which GDNPs exert their protective effects against alcoholic liver injury, we examined the expression of oxidative stress-related genes and analysed inflammatory responses in vitro and in vivo. The experimental findings were verified using network pharmacology. METHODS: The composition of the GDNPs was analysed using liquid chromatography-mass spectrometry. GDNPs were extracted and purified using differential ultracentrifugation and sucrose density gradient centrifugation. In vitro models of alcoholic liver injury were established using LO2 cells, whereas C57BL/6 J mice were used as in vivo models. Oxidative stress, inflammation, and liver injury indicators were measured using appropriate kits. Levels of proteins associated with oxidative stress and inflammation were measured via western blot, while nuclear factor erythroid2-related factor 2 (Nrf2) and NF-κB protein expression was tested using immunofluorescence, immunohistochemistry, and flow cytometry. The levels of relevant transcription factors were determined using qPCR. Experimental haematoxylin and eosin staining was used to characterise the liver histological appearance and damage in mice. Network pharmacological analysis of GDNP mRNA sequencing of GDNPs was used to predict drug targets and disease associations using TCMSP. RESULTS: GDNPs primarily included 77 compounds, including organic acids and their derivatives, amino acids and their derivatives, sugars, terpenoids, and flavonoids. GDNPs have features that allow them to be taken up by LO2 cells and promote their proliferation. In vitro data indicated that GDNPs reduced the levels of alcohol-induced reactive oxygen species by activating the Nrf2/HO-1 signalling pathway, whilst inhibiting the NF-κB pathway and thereby reducing NO, tumour necrosis factor-α, and interleukin-1ß levels to alleviate inflammation. An in vivo model showed that GDNPs improved the liver parameters and pathology in mice with alcoholic liver injury. GDNPs activate the Nrf2/HO-1/Keap1 signalling pathway in a p62-dependent manner to exert antioxidant effects. Furthermore, the TLR4/NF-κB signalling pathway was involved in the in vivo anti-inflammatory effect. Network pharmacology also confirmed that the effects of GDNPs on liver disease were associated with oxidative stress and inflammation-related targets and pathways. CONCLUSION: This study showed for the first time that GDNPs can alleviate alcohol-induced liver damage by activating the Nrf2/HO1 signalling pathway and blocking the NF-κB signalling pathway, thus lowering oxidative stress and inflammatory responses. Hereby, we present the Nrf2/HO1 and NF-κB signalling pathways as potential targets and GDNPs as a novel therapeutic approach for the management of alcohol-induced liver damage.

The Extracts Derived from Artemisia japonica Thunb. Leaves Mitigate Oxidative Stress and Inflammatory Response Induced by LPS in RAW264.7 Cells through Modulation of the Nrf2/HO-1 Signaling Pathway.

Artemisia japonica Thunb. has been used as a traditional Chinese medicine and a vegetable for thousands of years in China. However, there are few reports on the chemical composition and biological activity of its leaves. Thus, this study aimed to evaluate the chemical composition, antioxidant and anti-inflammatory effects of water extracts of A. japonica leaves and their underlying mechanisms. A total of 48 compounds were identified in the water extract using UPLC-QTOF-MS2 analysis, with phenolic acids, particularly chlorogenic acid compounds, being the predominant components. The ethyl acetate fraction (EAF) contained most of the total phenolic content (385.4217 mg GAE/g) and displayed superior antioxidant capacity with the IC50DPPH•, IC50ABTS•+, and OD0.5reducing power at 10.987 µg/mL, 43.630 µg/mL and 26.883 µg/mL, respectively. Furthermore, EAF demonstrated potent antioxidant and anti-inflammatory effects in LPS-induced RAW264.7 cells by upregulating the Nrf2/HO-1 signal pathway. These findings highlight that A. japonica leaves possess remarkable abilities to mitigate inflammation and oxidative stress, suggesting their potential utilization as medicinal agents and food additives for promoting human health.

Ethanol extract of Eclipta prostrata induces multiple myeloma ferroptosis via Keap1/Nrf2/HO-1 axis.

BACKGROUND: Multiple myeloma (MM) is an incurable hematological malignancy with limited therapeutic efficacy. Eclipta prostrata is a traditional Chinese medicinal plant reported to possess antitumor properties. However, the effects of E. prostrata in MM have not been explored. PURPOSE: The aim of this study was to define the mechanism of the ethanol extract of E. prostrata (EEEP) in treating MM and identify its major components. METHODS: The pro-ferroptotic effects of EEEP on cell death, cell proliferation, iron accumulation, lipid peroxidation, and mitochondrial morphology were determined in RPMI-8226 and U266 cells. The expression levels of nuclear factor erythroid 2-related factor 2 (Nrf2), kelch-like ECH-associated protein 1 (Keap1), heme oxygenase-1 (HO-1), glutathione peroxidase 4 (GPX4), and 4-hydroxynonenal (4HNE) were detected using western blotting during EEEP-mediated ferroptosis regulation. The RPMI-8226 and U266 xenograft mouse models were used to explore the in vivo anticancer effects of EEEP. Finally, high performance liquid chromatography (HPLC) and ultra-high-performance liquid chromatography-quadrupole/time-of-flight mass spectrometry system (UPLC-Q/TOF-MS) were used to identify the major constituents of EEEP. RESULTS: EEEP inhibited MM cell growth and induced cell death in vitro and in vivo. By promoting malondialdehyde and Fe2+ accumulation, lipid peroxidation, and GSH suppression, EEEP triggers ferroptosis in MM. Mechanistically, EEEP regulates the Keap1/Nrf2/HO-1 axis and stimulates ferroptosis. EEEP-induced lipid peroxidation and malondialdehyde accumulation were blocked by the Nrf2 activator NK-252. In addition, HPLC and UPLC-Q/TOF-MS analysis elucidated the main components of EEEP, including demethylwedelolactone, wedelolactone, chlorogenic acid and apigenin, which may play important roles in the anti-tumor function of EEEP. CONCLUSION: In summary, EEEP exerts its anti-MM function by inducing MM cell death and inhibiting tumor growth in mice. We also showed that EEEP can induce lipid peroxidation and accumulation of ferrous irons in MM cells both in vivo and in vitro, leading to ferroptosis. In addition, this anti-tumor function may be achieved by the EEEP activation of Keap1/Nrf2/HO-1 axis. This is the first study to reveal that EEEP exerts anti-MM activity through the Keap1/Nrf2/HO-1-dependent ferroptosis regulatory axis, making it a promising candidate for MM treatment.

Argel's stemmoside C as a novel natural remedy for mice with alcohol-induced gastric ulcer based on its molecular mechanistic pathways.

ETHNOPHARMACOLOGICAL RELEVANCE: Solenostemma argel is widely distributed in Africa & Asia with traditional usage in alleviating abdominal colic, aches, & cramps. This plant is rich in phytochemicals, which must be explored for its pharmacological effects. PURPOSE: Peptic Ulcer Disease (PUD) is the digestion of the digestive tube. PUD not only interferes with food digestion & nutrient absorption, damages one of the largest defensive barriers against pathogenic micro-organisms, but also impedes drug absorption & bioavailability, rendering the oral route, the most convenient way, ineffective. Omeprazole, one of the indispensable cost-effective proton-pump inhibitors (PPIs) extensively prescribed to control PUD, is showing growing apprehensions toward multiple drug interactions & side effects. Hence, finding a natural alternative with Omeprazole-like activity & limited side effects is a medical concern. STUDY DESIGN: Therefore, we present Stemmoside C as a new gastroprotective phytochemical agent isolated from Solenostemma argel to be tested in upgrading doses against ethanol-induced gastric ulcers in mice compared to negative, positive, & reference Omeprazole groups. METHODS: We carried out in-depth pharmacological & histopathological studies to determine the possible mechanistic pathway. RESULTS: Our results showed that Stemmoside C protected the stomach against ethanol-induced gastric ulcers parallel to Omeprazole. Furthermore, the mechanistic studies revealed that Stemmoside C produced its effect using an orchestrated array of different mechanisms. Stemmoside C stimulates stomach defense by increasing COX-2, PGE-2, NO, & TFF-1 healing factors, IL-10 anti-inflammatory cytokine, & Nrf-2 & HO-1 anti-oxidant pathways. It also suppresses stomach ulceration by inhibiting leucocyte recruitment, especially neutrophils, leading to subsequent inhibition of NF-κBp65, TNF-α, IL-1ß, & iNOS pro-inflammatory cytokines & JAK-1/STAT-3 inflammation-induced carcinogenicity cascade in addition to MMP-9 responsible for tissue degradation. CONCLUSION: These findings cast light on Stemmoside C's clinical application against gastric ulcer progression, recurrence, & tumorigenicity & concurrently with chemotherapy.

Berberine alleviates chlorpyrifos-induced nephrotoxicity in rats via modulation of Nrf2/HO-1 axis.

Chlorpyrifos (CPS), an organophosphorus insecticide, is widely used for agricultural and non-agricultural purposes with hazardous health effects. Berberine (BBR) is a traditional Chinese medicine and a phytochemical with anti-inflammatory and anti-oxidative properties. The present study evaluated the effects of BBR against kidney damage induced by CPS and the underlying mechanisms. An initial study indicated that BBR 50 mg/kg was optimal under our experimental conditions. Then, 24 rats (6/group) were randomized into: control, BBR (50 mg/kg/day), CPS (10 mg/kg/day), and CPS + BBR. BBR was administration 1 h prior to CPS. Each treatment was delivered daily for a period of 28 consecutive days using a gastric gavage tube. Compared to CPS-alone treated rats, BBR effectively improved renal function by preventing the rise in serum urea, creatinine, and uric levels. The reno-protective effects of BBR were confirmed through a histological examination of kidney tissues. BBR restored oxidant-antioxidant balance in renal tissues mediated by Keap1/Nrf2/HO-1 axis modulation. In addition, BBR decreased nitric oxide (NO) and myeloperoxidase (MPO) activity. This was paralleled with the potent down-regulation of NF-κB. Furthermore, BBR exhibited anti-apoptotic activities supported by the upregulation of Bcl-2 and down-regulation of Bax and caspase-3 expression. In conclusion, our data suggest that BBR attenuates CPS-induced nephrotoxicity in rats by restoring oxidant-antioxidant balance and inhibiting inflammatory response and apoptosis in renal tissue. This is mediated, at least partly, by modulation of the Nrf2/HO-1 axis.

Age-Dependent Changes in Nrf2/Keap1 and Target Antioxidant Protein Expression Correlate to Lipoxidative Adducts, and Are Modulated by Dietary N-3 LCPUFA in the Hippocampus of Mice.

The brain has a high metabolism rate that may generate reactive oxygen and nitrogen species. Consequently, nerve cells require highly efficient antioxidant defenses in order to prevent a condition of deleterious oxidative stress. This is particularly relevant in the hippocampus, a highly complex cerebral area involved in processing superior cognitive functions. Most current evidence points to hippocampal oxidative damage as a causal effect for neurodegenerative disorders, especially Alzheimer's disease. Nuclear factor erythroid-2-related factor 2/Kelch-like ECH-associated protein 1 (Nrf2/Keap1) is a master key for the transcriptional regulation of antioxidant and detoxifying systems. It is ubiquitously expressed in brain areas, mainly supporting glial cells. In the present study, we have analyzed the relationships between Nrf2 and Keap1 isoforms in hippocampal tissue in response to aging and dietary long-chain polyunsaturated fatty acids (LCPUFA) supplementation. The possible involvement of lipoxidative and nitrosative by-products in the dynamics of the Nrf2/Keap1 complex was examined though determination of protein adducts, namely malondialdehyde (MDA), 4-hydroxynonenal (HNE), and 3-nitro-tyrosine (NTyr) under basal conditions. The results were correlated to the expression of target proteins heme-oxygenase-1 (HO-1) and glutathione peroxidase 4 (GPx4), whose expressions are known to be regulated by Nrf2/Keap1 signaling activation. All variables in this study were obtained simultaneously from the same preparations, allowing multivariate approaches. The results demonstrate a complex modification of the protein expression patterns together with the formation of adducts in response to aging and diet supplementation. Both parameters exhibited a strong interaction. Noticeably, LCPUFA supplementation to aged animals restored the Nrf2/Keap1/target protein patterns to the status observed in young animals, therefore driving a "rejuvenation" of hippocampal antioxidant defense.

SKP alleviates the ferroptosis in diabetic kidney disease through suppression of HIF-1α/HO-1 pathway based on network pharmacology analysis and experimental validation.

BACKGROUND: Diabetic kidney disease (DKD) represents a microvascular complication of diabetes mellitus. Shenkang Pills (SKP), a traditional Chinese medicine formula, has been widely used in the treatment of DKD and has obvious antioxidant effect. Ferroptosis, a novel mode of cell death due to iron overload, has been shown to be associated with DKD. Nevertheless, the precise effects and underlying mechanisms of SKP on ferroptosis in diabetic kidney disease remain unclear. METHODS: The active components of SKP were retrieved from the Traditional Chinese Medicine Systems Pharmacology (TCMSP) database. Protein-protein interaction (PPI) network and Herb-ingredient-targets gene network were constructed using Cytoscape. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were conducted utilizing the Metascape system database. Additionally, an in vivo model of DKD induced by Streptozotocin (STZ) was established to further investigate and validate the possible mechanisms underlying the effectiveness of SKP. RESULTS: We retrieved 56 compounds and identified 223 targets of SKP through the TCMSP database. Key targets were ascertained using PPI network analysis. By constructing a Herb-Ingredient-Targets gene network, we isolated the primary active components in SKP that potentially counteract ferroptosis in diabetic kidney disease. KEGG pathway enrichment analysis suggested that SKP has the potential to alleviate ferroptosis through HIF signaling pathway, thereby mitigating renal injury in DKD. In animal experiments, fasting blood glucose, 24 h urine protein, urea nitrogen and serum creatine were measured. The results showed that SKP could improve DKD. Results from animal experiments were also confirmed the efficacy of SKP in alleviating renal fibrosis, oxidative stress and ferroptosis in DKD mice. These effects were accompanied by the significant reductions in renal tissue expression of HIF-1α and HO-1 proteins. The mRNA and immunohistochemistry results were the same as above. CONCLUSIONS: SKP potentially mitigating renal injury in DKD by subduing ferroptosis through the intricacies of the HIF-1α/HO-1 signaling pathway.

Quercetin: A promising therapy for diabetic encephalopathy through inhibition of hippocampal ferroptosis.

BACKGROUND: The pathophysiology of diabetic encephalopathy (DE), a significant diabetes-related pathological complication of the central nervous system, is poorly understood. Ferroptosis is an iron-dependent regulated necrotic cell death process that mediates the development of neurodegenerative and diabetes-related lesions. Quercetin (QE) exerts anti-ferroptotic effects in various diseases. However, the roles of ferroptosis in DE and the potential anti-ferroptotic mechanisms of QE are unclear. PURPOSE: This study aimed to investigate if quercetin can ameliorate DE by inhibiting ferroptosis and to elucidate the potential anti-ferroptotic mechanisms of QE, thus providing a new perspective on the pathogenesis and prevention of DE. METHODS: The spontaneously type 2 diabetic Goto-Kakizak rats and high glucose (HG)-induced PC12 cells were used as animal and in vitro models, respectively. The Morris water maze test was performed to evaluate the cognition of rats. Pathological damage was examined using hematoxylin and eosin staining. Mitochondrial damage was assessed using transmission electron microscopy. Lipid peroxidation was evaluated by examining the levels of malondialdehyde, superoxide dismutase, and glutathione. Additionally, the contents of iron ions were quantified. Immunofluorescence and western blotting were carried out to poke the protein levels. Network pharmacology analysis was conducted to construct a protein-protein interaction network for the therapeutic targets of QE in DE. Additionally, molecular docking and cellular thermal shift assay was performed to examine the target of QE. RESULTS: QE alleviated cognitive impairment, decreased lipid peroxidation and iron deposition in the hippocampus, and upregulated the Nrf2/HO-1 signaling pathway. HG-induced ferroptosis in PC12 cells resulted in decreased cell viability accompanied by lipid peroxidation and iron deposition. QE mitigated HG-induced ferroptosis by upregulating the Nrf2/HO-1 pathway, which was partially suppressed upon Nrf2 inhibition. Network pharmacology analysis further indicated that the Nrf2/HO-1 signaling pathway is a key target of QE. Molecular docking experiments revealed that QE binds to KEAP1 through four hydrogen bonds. Moreover, QE altered the thermostability of KEAP1. CONCLUSION: These results indicated that QE inhibits ferroptosis in the hippocampal neurons by binding to KEAP1 and subsequently upregulating the Nrf2/HO-1 signaling pathway.

Effect fraction of Bletilla striata (Thunb.) Reichb.f. alleviates LPS-induced acute lung injury by inhibiting p47phox/NOX2 and promoting the Nrf2/HO-1 signaling pathway.

BACKGROUND & AIMS: The effect fraction of Bletilla striata (Thunb.) Reichb.f. (EFBS), a phenolic-rich extract, has significant protective effects on lipopolysaccharide (LPS)-induced acute lung injury (ALI), but its composition and molecular mechanisms are unclear. This study elucidated its chemical composition and possible protective mechanisms against LPS-induced ALI from an antioxidant perspective. METHODS: EFBS was prepared by ethanol extraction, enriched by polyamide column chromatography, and characterized using ultra-performance liquid chromatography/time-of-flight mass spectrometry. The LPS-induced ALI model and the RAW264.7 model were used to evaluate the regulatory effects of EFBS on oxidative stress, and transcriptome analysis was performed to explore its possible molecular mechanism. Then, the pathway by which EFBS regulates oxidative stress was validated through inhibitor intervention, flow cytometry, quantitative PCR, western blotting, and immunofluorescence techniques. RESULTS: A total of 22 compounds in EFBS were identified. The transcriptome analyses of RAW264.7 cells indicated that EFBS might reduce reactive oxygen species (ROS) production by inhibiting the p47phox/NADPH oxidase 2 (NOX2) pathway and upregulating the nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathway. Both in vitro and in vivo data confirmed that EFBS significantly inhibited the expression and phosphorylation of p47phox protein, thereby weakening the p47phox/NOX2 pathway and reducing ROS production. EFBS significantly increased the expression of Nrf2 in primary peritoneal macrophages and lung tissue and promoted its nuclear translocation, dose-dependent increase in HO-1 levels, and enhancement of antioxidant activity. In vitro, both Nrf2 and HO-1 inhibitors significantly reduced the scavenging effects of EFBS on ROS, further confirming that EFBS exerts antioxidant effects at least partially by upregulating the Nrf2/HO-1 pathway. CONCLUSIONS: EFBS contains abundant phenanthrenes and dibenzyl polyphenols, which can reduce ROS production by inhibiting the p47phox/NOX2 pathway and enhance ROS clearance activity by upregulating the Nrf2/HO-1 pathway, thereby exerting regulatory effects on oxidative stress and improving LPS-induced ALI.

Ginseng (Panax ginseng) leaf extract modulates the expression of heme oxygenase-1 to attenuate osteoclast differentiation.

Osteoporosis is an aging disease characterized by an imbalance between bone formation and resorption. However, drugs that inhibit bone resorption have various adverse effects. Ginseng (Panax ginseng), a prominent herbal medicine in East Asia for >2000 years, is renowned for its manifold beneficial properties, including antioxidant, anti-cancer, anti-diabetic, and anti-adipogenic activities. Despite its long history of use, the pharmacological functions of ginseng leaves are not yet fully comprehended. In this study, we evaluated the potential effects of ginseng leaf extract (GLE) on receptor activator of nuclear factor κB ligand (RANKL)-induced osteoclast differentiation in RAW264.7 macrophage cells. Tartrate-resistant acid phosphatase (TRAP) staining revealed that GLE had significant anti-osteoclastogenic activity. GLE significantly reduced mRNA levels of osteoclast differentiation markers including TRAP, nuclear factor of activated T cell cytoplasmic 1, and cathepsin K. It also suppressed the production of reactive oxygen species (ROS) and secretion of high mobility group box-1 (HMGB1) in RANKL-treated RAW264.7 cells. In addition, GLE upregulated dose- and time-dependently the expression of heme oxygenase-1 (HO-1), eventually suppressing ROS production and HMGB1 secretion. This effects of GLE were significantly reversed by Tin Protoporphyrin IX dichloride, an inhibitor of HO-1, and HO-1 shRNA, indicating that HO-1 potently inhibits RANKL-induced osteoclast differentiation by inhibiting ROS production and HMGB1 secretion. Taken together, these observations suggest that GLE could have therapeutic potential as a natural product-derived medicine for the treatment of bone disorders.

Moxibustion prevents tripterygium glycoside-induced oligoasthenoteratozoospermia in rats via reduced oxidative stress and modulation of the Nrf2/HO-1 signaling pathway.

Oligoasthenoteratozoospermia (OAT) decreases male fertility, seriously affecting the production of offspring. This study clarified the preventive impact of different moxibustion frequencies on OAT and selected the optimal frequency to elucidate the underlying mechanism. An OAT rat model was constructed by gavage of tripterygium glycosides (TGS) suspension. Daily moxibustion (DM) or alternate-day moxibustion (ADM) was administered on the day of TGS suspension administration. Finally, we selected DM for further study based on sperm quality and DNA fragmentation index, testicular and epididymal morphology, and reproductive hormone level results. Subsequently, the oxidative stress (OS) status was evaluated by observing the OS indices levels; malondialdehyde (MDA), 8-hydroxy-deoxyguanosine (8-OHdG), total antioxidant capacity (T-AOC), and total superoxide dismutase (T-SOD) in testicular tissue using colorimetry and enzyme-linked immunosorbent assay. Furthermore, heme oxygenase 1 (HO-1) and nuclear factor erythropoietin-2-related factor 2 (Nrf2) were evaluated using Western blotting. Immunohistochemistry was employed to locate and assess the expression of HO-1 and Nrf2 protein, while quantitative real-time polymerase chain reaction was utilized to detect their mRNA expression. MDA and 8-OHdG levels decreased following DM treatment, while T-SOD and T-AOC increased, suggesting that DM may prevent TGS-induced OAT in rats by decreasing OS in the testis. Furthermore, protein and mRNA expression of Nrf2 and HO-1 in the testis were elevated, indicating that DM may reduce OS by activating the signaling pathway of Nrf2/HO-1. Therefore, DM could prevent OAT in rats via the Nrf2/HO-1 pathway, thereby presenting a promising therapeutic approach against OAT.

Inhibitory effect of Incarvillea diffusa Royle extract in the formation of calcium oxalate nephrolithiasis by regulating ROS-induced Nrf2/HO-1 pathway in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Calcium oxalate (CaOx) kidney stones are widely acknowledged as the most prevalent type of urinary stones, with high incidence and recurrence rates. Incarvillea diffusa Royle (ID) is a traditionally used medicinal herb in the Miao Minzu of Guizhou province, China, for treating urolithiasis. However, the active components and the underlying mechanism of its pharmacodynamic effects remain unclear. AIM OF THE STUDY: This study aimed to investigate the potential inhibitory effect of the active component of ID on the formation of CaOx nephrolithiasis and elucidate the underlying mechanism. MATERIALS AND METHODS: In vivo, a CaOx kidney stone model was induced in Sprague-Dawley (SD) rats using an ethylene glycol and ammonium chloride protocol for four weeks. Forty-eight male SD rats were randomly assigned to 6 groups (n = 8): blank group, model group, apocynin group, and low, medium, and high dose of ID's active component (IDW) groups. After three weeks of administration, rat urine, serum, and kidney tissues were collected. Renal tissue damage and crystallization, Ox, BUN, Ca2+, CRE, GSH, MDA, SOD contents, and levels of IL-1ß, IL-18, MCP-1, caspase-1, IL-6, and TNF-α in urine, serum, and kidney tissue were assessed using HE staining and relevant assay kits, respectively. Protein expression of Nrf2, HO-1, p38, p65, and Toll-4 in kidney tissues was quantified via Western blot. The antioxidant capacities of major compounds were evaluated through DPPH, O2·-, and ·OH radical scavenging assays, along with their effects on intracellular ROS production in CaOx-induced HK-2 cells. RESULTS: We found that IDW could significantly reduce the levels of CRE, GSH, MDA, Ox, and BUN, and enhancing SOD activity. Moreover, it could inhibit the secretion of TNF-α, IL-1ß, IL-18, MCP-1, caspase-1, and decreased protein expression of Nrf2, HO-1, p38, p65, and Toll-4 in renal tissue. Three major compounds isolated from IDW exhibited promising antioxidant activities and inhibited intracellular ROS production in CaOx-induced HK-2 cells. CONCLUSIONS: IDW facilitated the excretion of supersaturated Ca2+ and decreased the production of Ox, BUN in SD rat urine, and mitigated renal tissue damage by regulating Nrf2/HO-1 signaling pathway. Importantly, the three major compounds identified as active components of IDW contributed to the inhibition of CaOx nephrolithiasis formation. Overall, IDW holds significant potential for treating CaOx nephrolithiasis.

Dual role of Nrf2/HO-1 pathway in Z-ligustilide-induced ferroptosis against AML cells.

BACKGROUND: The scarcity of drugs targeting AML cells poses a significant challenge in AML management. Z-Ligustilide (Z-LIG), a phthalide compound, shows promising pharmacological potential as a candidate for AML therapy. However, its precise selective mechanism remains unclear. PURPOSE: In order to assess the selective inducement effects of Z-LIG on ferroptosis in AML cells and explore the possible involvement of the Nrf2/HO-1 pathway in the regulation of ferroptosis. METHODS: Through in vitro cell proliferation and in vivo tumor growth tests, the evaluation of Z-LIG's anticancer activity was conducted. Ferroptosis was determined by the measurement of ROS and lipid peroxide levels using flow cytometry, as well as the observation of mitochondrial morphology. To analyze the iron-related factors, western blot analysis was employed. The up-regulation of the Nrf2/HO-1 axis was confirmed through various experimental techniques, including CRISPR/Cas9 gene knockout, fluorescent probe staining, and flow cytometry. The efficacy of Z-LIG in inducing ferroptosis was further validated in a xenograft nude mouse model. RESULTS: Our study revealed that Z-LIG specifically triggered lipid peroxidation-driven cell death in AML cells. Z-LIG downregulated the total protein and nuclear entrance levels of IRP2, resulting in upregulation of FTH1 and downregulation of TFR1. Z-LIG significantly increased the susceptibility to ferroptosis by upregulating ACSL4 levels and simultaneously suppressing the activity of GPX4. Notably, the Nrf2/HO-1 pathway displayed a twofold impact in the ferroptosis induced by Z-LIG. Mild activation suppressed ferroptosis, while excessive activation promoted it, mainly driven by ROS-induced labile iron pool (LIP) accumulation in AML cells, which was not observed in normal human cells. Additionally, Nrf2 knockout and HO-1 knockdown reversed iron imbalance and mitochondrial damage induced by Z-LIG in HL-60 cells. Z-LIG effectively inhibited the growth of AML xenografts in mice, and Nrf2 knockout partially weakened its antitumor effect by inhibiting ferroptosis. CONCLUSION: Our study presents biological proof indicating that the selective initiation of ferroptosis in leukemia cells is credited to the excessive activation of the Nrf2/HO-1 pathway triggered by Z-LIG.

Capsicum annuum var. abbreviatum Induces a Macrophage M2-Like Phenotype Mediated by Nrf2/HO-1 in LPS-Stimulated Macrophages.

Capsicum annuum var. abbreviatum (CAAE), which is in the genus Capsicum L. (Solanaceae), was found to be richer in polyphenols and flavonoids than other prevalent peppers of Capsicum annuum var. angulosum and Capsicum annuum. L. Yet, it is still unclear how CAAE reduces inflammation. In this study, we used the lipopolysaccharide-stimulated RAW264.7 macrophage cell line and bone marrow-derived macrophages to assess its anti-inflammatory activities. Initially, we discovered that CAAE decreased the levels of nitric oxide and inducible nitric oxide synthase. In addition, CAAE decreased the intracellular reactive oxygen species levels and increased the nuclear factor-erythroid 2-related factor 2 and heme oxygenase-1 compared with the phenotype of M2 macrophages. CAAE inhibited the activation of mitogen-activated protein kinases (MAPKs), including extracellular signal-regulated kinases, c-Jun N-terminal kinases, and p38 MAPKs. CAAE also inhibited the translocation of nuclear factor kappa B into nuclear, hence preventing the production of proinflammatory cytokines. Therefore, we suggest that CAAE might have potential as a candidate therapeutic agent for inflammatory diseases.

20(R)-ginsenoside Rg3 attenuates cerebral ischemia-reperfusion injury by mitigating mitochondrial oxidative stress via the Nrf2/HO-1 signaling pathway.

Reducing mitochondrial oxidative stress has become an important strategy to prevent neuronal death in ischemic stroke. Previous studies have shown that 20(R)-ginsenoside Rg3 can significantly improve behavioral abnormalities, reduce infarct size, and decrease the number of apoptotic neurons in cerebral ischemia/reperfusion injury rats. However, it remains unclear whether 20(R)-ginsenoside Rg3 can inhibit mitochondrial oxidative stress in ischemic stroke and the potential molecular mechanism. In this study, we found that 20(R)-ginsenoside Rg3 notably inhibited mitochondrial oxidative stress in middle cerebral artery occlusion/reperfusion (MCAO/R) rats and maintained the stability of mitochondrial structure and function. Treatment with 20(R)-ginsenoside Rg3 also decreased the levels of mitochondrial fission proteins (Drp1 and Fis1) and increased the levels of fusion proteins (Opa1, Mfn1, and Mfn2) in MCAO/R rats. Furthermore, we found that 20(R)-ginsenoside Rg3 promoted nuclear aggregation of nuclear factor erythroid2-related factor 2 (Nrf2) but did not affect Kelch-like ECH-associated protein-1 (Keap1), resulting in the downstream expression of antioxidants. In in vitro oxygen-glucose deprivation/reperfusion stroke models, the results of PC12 cells treated with 20(R)-ginsenoside Rg3 were consistent with animal experiments. After transfection with Nrf2 short interfering RNA (siRNA), the protective effect of 20(R)-ginsenoside Rg3 on PC12 cells was reversed. In conclusion, the inhibition of mitochondrial oxidative stress plays a vital position in the anti-cerebral ischemia-reperfusion injury of 20(R)-ginsenoside Rg3, and its neuroprotective mechanism is related to the activation of the nuclear factor erythroid2-related factor 2/heme oxygenase 1 signaling pathway.

Allicin ameliorates sepsis-induced acute kidney injury through Nrf2/HO-1 signaling pathway.

Acute kidney injury (AKI) is a complication that can be induced by different factors. Allicin is a class of organic sulfur compounds with anticancer and antibacterial effects, and has not been reported in sepsis-induced AKI (S-AKI). S-AKI was induced in c57BL/6 mice by cecal ligation puncture. In response to the treatment of allicin, the survival rate of mice with S-AKI was increased. Reduced levels of serum creatinine, blood urea nitrogen, UALB, KIM-1 and NGAL indicated an improvement in renal function of S-AKI mice. Allicin inhibited the inflammation and cell apoptosis, which evidenced by decreased levels of inflammatory cytokines and apoptosis-related proteins. Oxidative stress was evaluated by the levels of oxidative stress biomarkers, and suppressed by allicin. In addition, allicin-alleviated mitochondrial dysfunction was characterized by decreased JC-1 green monomer. These effects of allicin were also evidenced in HK2 cells primed with lipopolysaccharide (LPS). Both in vivo and in vitro experiments showed that the nuclear translocation of Nrf2 and the expression of HO-1 increased after allicin treatment, which was confirmed by ML385 and CDDO-Me. In summary, this study revealed the alleviating effect of allicin on S-AKI and demonstrated the promotive effect of allicin on nuclear translocation of Nrf2 for the first time. It was inferred that allicin inhibited the progression of S-AKI through Nrf2/HO-1 signaling pathway. This study makes contributions to the understanding of the roles of allicin in S-AKI.