[Protective effect and mechanism of quercetin on acute liver injury induced by diquat poisoning in mice].

OBJECTIVE: To investigate the protective effect of quercetin (QR) on acute liver injury induced by diquat (DQ) poisoning in mice and its mechanism. METHODS: Eighty healthy male C57BL/6 mice with SPF grade were randomly divided into control group, DQ model group, QR treatment group, and QR control group, with 20 mice in each group. The DQ poisoning model was established by a one-time intraperitoneal injection of DQ solution (40 mg/kg); the control and QR control groups received equivalent amounts of distilled water through intraperitoneal injection. Four hours after modeling, the QR treatment group and the QR control group received 0.5 mL QR solution (50 mg/kg) through gavage. Meanwhile, an equivalent amount of distilled water was given orally to the control group and the DQ model group. The treatments above were administered once daily for seven consecutive days. Afterwards, the mice were anesthetized, blood and liver tissues were collected for following tests: changes in the structure of mice liver tissue were observed using transmission electron microscopy; the levels of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were detected using enzyme linked immunosorbent assay (ELISA); the levels of glutathione (GSH), superoxide dismutase (SOD), and malondialdehyde (MDA) in liver tissues were measured using the water-soluble tetrazolium-1 (WST-1) method, the thiobarbituric acid (TBA) method, and enzymatic methods, respectively; the protein expressions of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), Kelch-like ECH-associated protein 1 (Keap1), and activated caspase-9 in liver tissues were detected using Western blotting. RESULTS: Severe mitochondrial damage was observed in the liver tissues of mice in the DQ model group using transmission electron microscopy, yet mitochondrial damage in the QR treatment group showed significant alleviation. Compared to the control group, the DQ model group had significantly increased levels of MDA in liver tissue, serum AST, and ALT, yet had significantly decreased levels of GSH and SOD in liver tissue. In comparison to the DQ model group, the QR treatment group exhibited significant reductions in serum levels of ALT and AST, as well as MDA levels in liver tissue [ALT (U/L): 52.60±6.44 vs. 95.70±8.00, AST (U/L): 170.45±19.33 vs. 251.10±13.09, MDA (nmol/mg): 12.63±3.41 vs. 18.04±3.72], and notable increases in GSH and SOD levels in liver tissue [GSH (µmol/mg): 39.49±6.33 vs. 20.26±3.96, SOD (U/mg): 121.40±11.75 vs. 81.67±10.01], all the differences were statistically significant (all P < 0.01). Western blotting results indicated that the protein expressions of Nrf2 and HO-1 in liver tissues of the DQ model group were significantly decreased compared to the control group. On the other hand, the protein expressions of Keap1 and activated caspase-9 were conspicuously higher when compared to the control group. In comparison to the DQ model group, the QR treatment group showed a significant increase in the protein expressions of Nrf2 and HO-1 in liver tissues (Nrf2/ß-actin: 1.17±0.08 vs. 0.92±0.45, HO-1/ß-actin: 1.53±0.17 vs. 0.84±0.09). By contrast, there was a notable decrease in the protein expressions of Keap1 and activated caspase-9 (Keap1/ß-actin: 0.48±0.06 vs. 1.22±0.09, activated caspase-9/ß-actin: 1.17±0.12 vs. 1.59±0.30), the differences were statistically significant (all P < 0.01). CONCLUSIONS: QR may reduce acute liver injury induced by DQ poisoning in mice via activating Keap1/Nrf2 signaling pathway.

PRMT6-mediated ADMA promotes p62 phase separation to form a negative feedback loop in ferroptosis.

Purpose: Due to intrinsic defensive response, ferroptosis-activating targeted therapy fails to achieve satisfactory clinical benefits. Though p62-Keap1-Nrf2 axis is activated to form a negative feedback loop during ferroptosis induction, how p62 is activated remains largely unknown. Methods: MTS assay was applied to measure cell growth. Lipid ROS was detected with C11-BODIPY reagent by flow cytometer. Quantitative real-time PCR (qPCR) and western blotting were performed to determine mRNA and protein level. Immunofluorescence (IF) was performed to examine the distribution of proteins. Fluorescence recovery after photobleaching (FRAP) was adopted to evaluate p62 phase separation. Immunoprecipitation (IP), co-IP and Proximal ligation assay (PLA) were performed to detected protein posttranslational modifications and protein-protein interactions. Tumor xenograft model was employed to inspect in vivo growth of pancreatic cancer cells. Results: Upon ferroptosis induction, Nuclear Factor E2 Related Factor 2 (Nrf2) protein and its downstream genes such as HMOX1 and NQO1 were upregulated. Knockdown of p62 significantly reversed Nrf2 upregulation and Keap1 decrease after ferroptosis induction. Knockdown of either p62 or Nrf2 remarkably sensitized ferroptosis induction. Due to augmented p62 phase separation, formation of p62 bodies were increased to recruit Keap1 after ferroptosis induction. Protein arginine methyltransferase 6 (PRMT6) mediated asymmetric dimethylarginine (ADMA) of p62 to increase its oligomerization, promoting p62 phase separation and p62 body formation. Knockdown of p62 or PRMT6 notably sensitized pancreatic cancer cells to ferroptosis both in vitro and in vivo through suppressing Nrf2 signaling. Conclusion: During ferroptosis induction, PRMT6 mediated p62 ADMA to promote its phase separation, sequestering Keap1 to activate Nrf2 signaling and inhibit ferroptosis. Therefore, targeting PRMT6-mediated p62 ADMA could be a new option to sensitize ferroptosis for cancer treatment.

Dietary Walnuts Prevented Indomethacin-Induced Gastric Damage via AP-1 Transcribed 15-PGDH, Nrf2-Mediated HO-1, and n-3 PUFA-Derived Resolvin E1.

Non-steroidal anti-inflammatory drugs (NSAIDs), the most highly prescribed drugs in the world for the treatment of pain, inflammation, and fever, cause gastric mucosal damage, including ulcers, directly or indirectly, by which the development of GI-safer (-sparing) NSAIDs relates to unmet medical needs. This study aimed to document the preventive effects of walnut polyphenol extracts (WPEs) against NSAID-induced gastric damage along with the molecular mechanisms. RGM-1 gastric mucosal cells were administered with indomethacin, and the expressions of the inflammatory mediators between indomethacin alone or a combination with WPEs were compared. The expressions of the inflammatory mediators, including COX-1 and COX-2, prostaglandin E2, 15-hydroxyprostaglandin dehydrogenase (15-PGDH), and antioxidant capacity, were analyzed by Western blot analysis, RT-PCR, and ELISA, respectively. HO-1, Nrf-2, and keap1 were investigated. The in vivo animal models were followed with in vitro investigations. The NSAIDs increased the expression of COX-2 and decreased COX-1 and 15-PGDH, but the WPEs significantly attenuated the NSAID-induced COX-2 expression. Interestingly, the WPEs induced the expression of 15-PGDH. By using the deletion constructs of the 15-PGDH promoter, we found that c-Jun is the most essential determinant of the WPE-induced up-regulation of 15-PGDH expression. We confirmed that the knockdown of c-Jun abolished the ability of the WPEs to up-regulate the 15-PGDH expression. In addition, the WPEs significantly increased the HO-1 expression. The WPEs increased the nuclear translocation of Nrf2 by Keap-1 degradation, and silencing Nrf2 markedly reduced the WPE-induced HO-1 expression. We found that the WPE-induced HO-1 up-regulation was attenuated in the cells harboring the mutant Keap1, in which the cysteine 151 residue was replaced by serine. These in vitro findings were exactly validated in indomethacin-induced gastric rat models. Daily walnut intake can be a promising nutritional supplement providing potent anti-inflammatory, antioxidative, and mucosa-protective effects against NSAID-induced GI damage.

Association of Α-Klotho with regulation of Keap1/Nrf2/Interleukin-1 pathway and AMPA receptor trafficking in the brain of suicide victims.

Suicide is a significant public health challenge worldwide. Statistical data confirm a strong relationship between suicidal behavior and depressive disorders (DDs), but the molecular mechanisms of these diseases are still poorly understood. A growing body of research suggests that the Klotho-mediated pathway may be a novel intracellular target for the development of suicide-related disorders (including DDs). To verify this hypothesis, the link between α-Klotho levels, Nrf2-related inflammatory status (IL-1α, IL-1ß, Keap1, NFκB p65), AMPA (GluA1, GluA2, p-S831-GluA1, p-S845-GluA1) receptor subunit trafficking and AMPK (AMPKα1/2; pT172-AMPKα1) signalling pathways in the brain of suicide victims as compared to controls were investigated. Commercially available enzyme-linked immunoassay (ELISA) and Western blot analysis were performed in the hippocampus (HP) and frontal cortex (FCx) of suicide victims and matched controls. Group differences were assessed using an unpaired Student's t-test. A statistically significant decrease in the level of α-Klotho (HP: p=0.001; FCx: p=0.012) with an increase in IL-1ß (HP: p=0.0108) and IL-1α (FCx: p=0.009) concentrations were shown. These alterations were associated with increased Keap1 (FCx: p=0.023) and NF-κB-p65 (HP: p=0.039; FCx: p=0.013 nuclear fraction) protein levels. Furthermore, a significant reduction in p-S831-GluA1 (HP: p=0.029; FCx=0.002) and p-S845-GluA1 (HP: p=0.0012) proteins was observed. Similarly, the level of GluA2 (HP: p=0.011; FCx: p=0.002) and in p-T172-AMPKα1 (HP: p=0.0288; FCx: p=0.0338) protein were statistically decreased. Our findings demonstrate that a reduction in α-Klotho levels in brain structures related to mood disorders (HP, FCx) correlates with suicidal behavior. Moreover, our study provides novel insights into the molecular mechanisms underlying suicide-related disorders, highlighting the role of α-Klotho, Nrf2-related inflammatory status, AMPA receptor trafficking, and AMPK signaling pathways in the pathophysiology of suicidal behavior. These results may have implications for the development of targeted interventions for individuals at risk of suicide.

Plumbagin ameliorates LPS-induced acute lung injury by regulating PI3K/AKT/mTOR and Keap1-Nrf2/HO-1 signalling pathways.

Acute lung injury (ALI) is a major pathophysiological problem characterized by severe inflammation, resulting in high morbidity and mortality. Plumbagin (PL), a major bioactive constituent extracted from the traditional Chinese herb Plumbago zeylanica, has been shown to possess anti-inflammatory and antioxidant pharmacological activities. However, its protective effect on ALI has not been extensively studied. The objective of this study was to investigate the protective effect of PL against ALI induced by LPS and to elucidate its possible mechanisms both in vivo and in vitro. PL treatment significantly inhibited pathological injury, MPO activity, and the wet/dry ratio in lung tissues, and decreased the levels of inflammatory cells and inflammatory cytokines TNF-α, IL-1ß, IL-6 in BALF induced by LPS. In addition, PL inhibited the activation of the PI3K/AKT/mTOR signalling pathway, increased the activity of antioxidant enzymes CAT, SOD, GSH and activated the Keap1/Nrf2/HO-1 signalling pathway during ALI induced by LPS. To further assess the association between the inhibitory effects of PL on ALI and the PI3K/AKT/mTOR and Keap1/Nrf2/HO-1 signalling, we pretreated RAW264.7 cells with 740Y-P and ML385. The results showed that the activation of PI3K/AKT/mTOR signalling reversed the protective effect of PL on inflammatory response induced by LPS. Moreover, the inhibitory effects of PL on the production of inflammatory cytokines induced by LPS also inhibited by downregulating Keap1/Nrf2/HO-1 signalling. In conclusion, the results indicate that the PL ameliorate LPS-induced ALI by regulating the PI3K/AKT/mTOR and Keap1-Nrf2/HO-1 signalling, which may provide a novel therapeutic perspective for PL in inhibiting ALI.

Oxidative and carbonyl stress induced AMD and Codonopsis lanceolata ameliorates AMD via controlling oxidative and carbonyl stress.

Age-related macular degeneration (AMD) is one of the leading causes of blindness. AMD is currently incurable; the best solution is to prevent its occurrence. To develop drugs for AMD, it is crucial to have a model system that mimics the symptoms and mechanisms in patients. It is most important to develop safer and more effective anti-AMD drug. In this study, the dose of A2E and the intensity of blue light were evaluated to establish an appropriate atrophic in vitro model of AMD and anti-AMD effect and therapeutic mechanism of Codonopsis lanceolata. The experimental groups included a control group an AMD group treated with A2E and blue light, a lutein group treated with 25 µM lutein after AMD induction, and three groups treated with different doses of C. lanceolata (10, 20, and 50 µg/mL) after AMD induction. Intrinsic apoptotic pathway (Bcl-2 family), anti-oxidative system (Keap1/Nrf2/HO-1 antioxidant response element), and anti-carbonyl effect (4-hydroxynonenal [4-HNE]) were evaluated using immunofluorescence, MTT, TUNEL, FACS, and western blotting analyses. A2E accumulation in the cytoplasm of ARPE-19 cells depending on the dose of A2E. Cell viability of ARPE-19 cells according to the dose of A2E and/or blue light intensity. The population of apoptotic or necrotic cells increased based on the A2E dose and blue light intensity. Codonopsis lanceolata dose-dependently prevented cell death which was induced by A2E and blue light. The antiapoptotic effect of that was caused by activating Keap1/Nrf2/HO-1 pathway, suppressing 4-HNE, and modulating Bcl-2 family proteins like increase of antiapoptotic proteins such as Bcl-2 and Bcl-XL and decrease of proapoptotic protein such as Bim. Based on these findings, 30 µM A2E and 20 mW/cm2 blue light on adult retinal pigment epithelium-19 cells was an appropriate condition for AMD model and C. lanceolata shows promise as an anti-AMD agent.

Regulation of Keap1-Nrf2 signaling in health and diseases.

Nuclear factor erythroid 2-related factor 2 (Nrf2) functions as a central regulator in modulating the activities of diverse antioxidant enzymes, maintaining cellular redox balance, and responding to oxidative stress (OS). Kelch-like ECH-associated protein 1 (Keap1) serves as a principal negative modulator in controlling the expression of detoxification and antioxidant genes. It is widely accepted that OS plays a pivotal role in the pathogenesis of various diseases. When OS occurs, leading to inflammatory infiltration of neutrophils, increased secretion of proteases, and the generation of large quantities of reactive oxygen radicals (ROS). These ROS can oxidize or disrupt DNA, lipids, and proteins either directly or indirectly. They also cause gene mutations, lipid peroxidation, and protein denaturation, all of which can result in disease. The Keap1-Nrf2 signaling pathway regulates the balance between oxidants and antioxidants in vivo, maintains the stability of the intracellular environment, and promotes cell growth and repair. However, the antioxidant properties of the Keap1-Nrf2 signaling pathway are reduced in disease. This review overviews the mechanisms of OS generation, the biological properties of Keap1-Nrf2, and the regulatory role of its pathway in health and disease, to explore therapeutic strategies for the Keap1-Nrf2 signaling pathway in different diseases.

Effects of KRAS, STK11, KEAP1, and TP53 mutations on the clinical outcomes of immune checkpoint inhibitors among patients with lung adenocarcinoma.

BACKGROUND: This study aimed to identify the associations between individual KRAS, STK11, KEAP1, or TP53 mutations, as well as the comutation status of these genes, and the tumor mutation burden (TMB) with clinical outcomes of lung adenocarcinoma patients treated with immune checkpoint inhibitors (ICIs). METHODS: We collected data from patients with lung adenocarcinoma treated with ICIs from the Center for Cancer Genomics and Advanced Therapeutics (C-CAT) database between June 2019 and August 2023. The main endpoints were the treatment response and overall survival (OS). RESULTS: Among 343 patients with lung adenocarcinoma, 61 (18%), 69 (20%), 41 (12%), and 222 (65%) patients had KRAS, STK11, KEAP1, and TP53 mutations, respectively. An overall objective response was observed in 94 of 338 patients (28%), including 2 (1%) who achieved a complete response and 92 (27%) who achieved a partial response. Patients with STK11, KEAP1, or TP53 mutations had a significantly greater TMB (P<0.001). According to the univariate analysis, the treatment response was significantly correlated with TP53 mutation in both the general (P = 0.041) and KRAS wild-type (P = 0.009) populations. KEAP1 and TP53 mutations were associated with worse OS among assessable patients (hazard ratio (HR) = 2.027, P = 0.002; HR = 1.673, P = 0.007, respectively) and among patients without KRAS mutations (HR = 1.897, P = 0.012; HR = 1.908, P = 0.004, respectively). According to the multivariate analysis, KEAP1 (HR = 1.890, P = 0.008) and TP53 (HR = 1.735, P = 0.011) mutations were found to be independent factors for OS. CONCLUSIONS: STK11, KEAP1, and TP53 mutations are significantly associated with a high TMB. TP53 mutation could affect the treatment response to some degree, and both KEAP1 and TP53 mutations resulted in inferior OS in the general patient population and in those with KRAS-wild-type lung adenocarcinoma, indicating that KEAP1 and TP53 mutations might act as prognostic factors for ICI treatment in lung adenocarcinoma patients.

Modulation of keap-1/Nrf2/HO-1 and NF-ĸb/caspase-3 signaling pathways by dihydromyricetin ameliorates sodium valproate-induced liver injury.

Nuclear factor erythroid factor 2 (Nrf2) is the key regulatory of the antioxidant response elements. Also, Nrf2 interacts with nuclear factor kappa B (NF-ĸB) to inhibit subsequent inflammatory cascade. Activation of Nrf2 signaling ameliorates drug-induced liver injury. Sodium valproate (SVP) is an anti-epilepsy drug with a hepatotoxic adverse effect that restricts its clinical use. In this study, coadministration of Dihydromyricetin (DHM), a natural flavonoid, with SVP to rats upregulated gene expression of Nrf2 and its downstream gene, heme oxygenase 1 (HO-1), while suppressed the Nrf2 repressor, Keap-1. Additionally, DHM led to downregulation of proinflammatory factors in liver tissues, including NF-ĸB, interleukin 1 beta (IL-1ß), and tumor necrosis factor alpha (TNF-α). This was accompanied by a decrease in the proapoptotic protein (cleaved caspase-3) expression level. Furthermore, biochemical and histopathological studies showed that DHM treatment improved liver function and lipid profile while decreased inflammatory cell infiltration, congestion, and hepatocellular damage. According to our knowledge, prior research has not examined the protective effect of DHM on the liver injury induced by SVP. Consequently, this study provides DHM as a promising herbal medication that, when used with SVP, can prevent its induced hepatotoxicity owing to its potential anti-oxidative, anti-inflammatory, and anti-apoptotic properties.

Spilanthes filicaulis (Schumach. & Thonn.) C. D Adam leaf extract prevents assault of streptozotocin on liver cells via inhibition of oxidative stress and activation of the NrF2/Keap1, PPARγ, and PTP1B signaling pathways.

BACKGROUND: Spilanthes filicaulis (Schumach. & Thonn.) C. D Adam is a shrubby plant of the Asteraceae family that has medicinal benefits for the pharmaceutical and cosmetic industries. PURPOSE: The purpose of this study was to assess the effectiveness of Spilanthes filicaulis leaf extract in a streptozotocin (STZ)-induced rat model and the associated signaling pathways. METHODS: A sample of 25 male Wistar rats was randomly assigned to groups I, II, III, IV, and V. Each group included five animals, i.e., control rats, diabetic control rats, diabetic rats treated with metformin, and diabetic rats treated with 150 mg/kg/bw and 300 mg/kg/bw of the methanolic extract of S. filicaulis leaves (MESFL). Treatment was administered for 15 successive days via oral gavage. After 15 days, the rats were evaluated for fasting blood glucose (FBG), glycated hemoglobin (HbA1c), alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), triglyceride (TG), total cholesterol (TC), low-density lipoprotein (LDL), high-density lipoprotein (HDL), reduced glutathione (GSH), glutathione-S-transferase (GST), superoxide dismutase (SOD), catalase (CAT), lipid peroxidation (MDA), hexokinase, and glucose-6-phosphatase activities. Gene expression levels of nuclear factor erythroid 2-related factor 2 (Nrf2), peroxisome proliferator-activated receptor gamma (PPAR-γ), kelch-like ECH-associated protein 1 (Keap1), protein tyrosine phosphatase 1B (PTP1B) and the antiapoptotic protein caspase-3 were examined. RESULTS: MESFL was administered to diabetic rats, and changes in body weight, fasting blood glucose (FBG) and HbA1c were restored. Furthermore, in diabetic rats, S. filicaulis significantly reduced the levels of triglycerides (TGs), total cholesterol (TC), low-density lipoprotein (LDL), and very low-density lipoprotein (VLDL) and significantly increased HDL. S. filicaulis improved ALT, AST, and ALP enzyme activity in diabetic rats. MDA levels decreased considerably with increasing activity of antioxidant enzymes, such as GST, SOD, CAT and GSH, in diabetic liver rats treated with S. filicaulis. Diabetic rats treated with MESFL and metformin exhibited upregulated mRNA expression levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and peroxisome proliferator-activated receptor gamma (PPAR-γ). Kelch-like ECH-associated protein 1 (Keap1) and protein tyrosine phosphatase 1B (PTP1B) mRNA expression in the liver was downregulated in diabetic rats treated with MESFL and metformin. In addition, MESFL downregulated the mRNA expression of caspase-3 in diabetic rats. CONCLUSION: It can be concluded from the data presented in this study that MESFL exerts a protective effect on diabetic rats due to its antidiabetic, antioxidant, antihyperlipidemic and antiapoptotic effects and may be considered a treatment for T2DM.

PPIA dictates NRF2 stability to promote lung cancer progression.

Nuclear factor erythroid 2-related factor 2 (NRF2) hyperactivation has been established as an oncogenic driver in a variety of human cancers, including non-small cell lung cancer (NSCLC). However, despite massive efforts, no specific therapy is currently available to target NRF2 hyperactivation. Here, we identify peptidylprolyl isomerase A (PPIA) is required for NRF2 protein stability. Ablation of PPIA promotes NRF2 protein degradation and blocks NRF2-driven growth in NSCLC cells. Mechanistically, PPIA physically binds to NRF2 and blocks the access of ubiquitin/Kelch Like ECH Associated Protein 1 (KEAP1) to NRF2, thus preventing ubiquitin-mediated degradation. Our X-ray co-crystal structure reveals that PPIA directly interacts with a NRF2 interdomain linker via a trans-proline 174-harboring hydrophobic sequence. We further demonstrate that an FDA-approved drug, cyclosporin A (CsA), impairs the interaction of NRF2 with PPIA, inducing NRF2 ubiquitination and degradation. Interestingly, CsA interrupts glutamine metabolism mediated by the NRF2/KLF5/SLC1A5 pathway, consequently suppressing the growth of NRF2-hyperactivated NSCLC cells. CsA and a glutaminase inhibitor combination therapy significantly retard tumor progression in NSCLC patient-derived xenograft (PDX) models with NRF2 hyperactivation. Our study demonstrates that targeting NRF2 protein stability is an actionable therapeutic approach to treat NRF2-hyperactivated NSCLC.

CRHR1 antagonist alleviated depression-like behavior by downregulating p62 in a rat model of post-stroke depression.

Post-stroke depression (PSD) is a complication of cerebrovascular disease, which can increase mortality after stroke. CRH is one of the main signaling peptides released after activation of the hypothalamic-pituitary-adrenal (HPA) axis in response to stress. It affects synaptic plasticity by regulating inflammation, oxidative stress and autophagy in the central nervous system. And the loss of spines exacerbates depression-like behavior. Therefore, synaptic deficits induced by CRH may be related to post-stroke depression. However, the underlying mechanism remains unclear. The Keap1-Nrf2 complex is one of the core components of the antioxidant response. As an autophagy associated protein, p62 participates in the Keap1-NrF2 pathway through its Keap1 interaction domain. Oxidative stress is involved in the feedback regulation between Keap1-Nrf2 pathway and p62.However, whether the relationship between CRH and the Keap1-Nrf2-p62 pathway is involved in PSD remains unknown. This study found that serum levels of CRH in 22 patients with PSD were higher than those in healthy subjects. We used MCAO combined with CUMS single-cage SD rats to establish an animal model of PSD. Animal experiments showed that CRHR1 antagonist prevented synaptic loss in the hippocampus of PSD rats and alleviated depression-like behavior. CRH induced p62 accumulation in the prefrontal cortex of PSD rats through CRHR1. CRHR1 antagonist inhibited Keap1-Nrf2-p62 pathway by attenuating oxidative stress. In addition, we found that abnormal accumulation of p62 induces PSD. It alleviates depression-like behavior by inhibiting the expression of p62 and promoting the clearance of p62 in PSD rats. These findings can help explore the pathogenesis of PSD and design targeted treatments for PSD.

Therapeutic potential of salvigenin to combat atrazine induced liver toxicity in rats via regulating Nrf-2/Keap-1 and NF-κB pathway.

Atrazine (ATR) is the second most extensively used herbicide which adversely affects the body organs including liver. Salvigenin (SGN) is a flavonoid which demonstrates a wide range of biological and pharmacological abilities. This study was planned to assess the protective ability of SGN to avert ATR induced liver damage in rats. Thirty-two rats (Rattus norvegicus) were divided into four groups including control, ATR (5 mg/kg), ATR (5 mg/kg) + SGN (10 mg/kg) and SGN (10 mg/kg) alone supplemented group. ATR exposure reduced the expression of Nrf-2 while instigating an upregulation in Keap-1 expression. Furthermore, the activities of catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD), heme­oxygenase-1 (HO-1) and glutathione reductase (GSR) contents were decreased while increasing reactive oxygen species (ROS) and malondialdehyde (MDA) levels after ATR treatment. Moreover, ATR poisoning increased the levels of ALT, AST, and ALP while reducing the levels of total proteins, and albumin in hepatic tissues of rats. Besides, ATR administration escalated the expressions of Bax and Caspase-3 while inducing a downregulation in the expressions of Bcl-2. Similarly, ATR intoxication increased the levels of Interleukin-6 (IL-6), Nuclear factor kappa-B (NF-κB), Interleukin-1ß (IL-1ß), tumor necrosis factor-α (TNF-α), and the activity of cyclooxygenase-2 (COX-2). Furthermore, ATR disrupted the normal histology of hepatic tissues. However, SGN treatment remarkably protected the liver tissues via regulating antioxidant, anti, inflammatory, anti-apoptotic as well as histology parameters. Therefore, it is concluded that SGN can be used as therapeutic agent to combat ATR-induced hepatotoxicity.

Chemopreventive effects of atractylenolide-III on mammary tumorigenesis via activation of the Nrf2/ARE pathway through autophagic degradation of Keap1.

The incidence of breast cancer is increasing annually, making it a major health threat for women. Chemoprevention using natural, dietary, or synthetic products has emerged as a promising approach to address this growing burden. Atractylenolide-III (AT-III), a sesquiterpenoid present in various medicinal herbs, has demonstrated potential therapeutic effects against several diseases, including tumors, nonalcoholic fatty liver disease, and cerebral ischemic injury. However, its impact on breast cancer chemoprevention remains unexplored. In this study, we used an N-methyl-N-nitrosourea (NMU)-induced rat breast cancer model and 17ß-estradiol (E2)-treated MCF-10A cells to evaluate the chemopreventive potential of AT-III on mammary tumorigenesis. AT-III inhibited mammary tumor progression, evidenced by reduced tumor volume and multiplicity, prolonged tumor latency, and the reversal of NMU-induced weight loss. Furthermore, AT-III suppressed NMU-induced inflammation and oxidative stress through the Nrf2/ARE pathway in breast cancer tissues. In vitro, AT-III effectively suppressed E2-induced anchorage-independent growth and cell migration in MCF-10A cells. Nrf2 knockdown attenuated the protective effects of AT-III, highlighting the pivotal role of Nrf2 in AT-III-mediated suppression of tumorigenesis. The mechanism involves the induction of Nrf2 expression by AT-III through the autophagic degradation of Kelch-like ECH-associated protein 1 (Keap1). Overall, the results of this study indicate that AT-III is a promising candidate for breast cancer chemoprevention and provide valuable insights into its molecular interactions and signaling pathways.

Qifu-yin activates the Keap1/Nrf2/ARE signaling and ameliorates synaptic injury and oxidative stress in APP/PS1 mice.

ETHNOPHARMACOLOGICAL RELEVANCE: The traditional medicinal formulation, Qifu-yin (QFY), has been widely prescribed for Alzheimer's disease (AD) treatment in China, yet the comprehensive mechanisms through which QFY mitigates AD pathology remain to be fully delineated. AIM OF THE STUDY: This study aimed to explore the therapeutic implications of QFY on the synaptic injury and oxidative stress in the hippocampus of APPswe/PS1dE9 (APP/PS1) mice, with a concerted effort to elucidate the molecular mechanisms related to synaptic preservation and memory improvement. MATERIALS AND METHODS: The components of QFY were identified by ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The neuroprotective effects of QFY was evaluated using six-month-old male APP/PS1 mice. Subsequent to a 15 days of QFY regimen, spatial memory was assessed utilizing the Morris water maze (MWM) test. Amyloid-beta (Aß) aggregation was detected via immunostaining, while the quantification of Aß1-40 and Aß1-42 was achieved through enzyme-linked immunosorbent assay (ELISA). Transmission electron microscopy (TEM) was used to investigate the synaptic structure and mitochondrial morphology. Golgi staining was applied to examine dendritic spine density. Reactive oxygen species (ROS), 3-nitrotyrosine (3-NT) and 4-hydroxy-nonenal (4-HNE) assays were employed to assess oxidative stress. The expression profiles of Aß metabolism-associated enzymes and the Keap1/Nrf2/ARE signaling pathway were determined by Western blot. RESULTS: A total of 20 principal compounds in QFY were identified. QFY mitigated memory deficits of APP/PS1 mice, including reducing escape latency and search distance and increasing the time and distance spent in the target quadrant. In addition, QFY increased platform crossings of APP/PS1 mice in the probe trial of MWM tests. TEM analysis showed that QFY increased synapse number in the CA1 region of APP/PS1 mice. Further studies indicated that QFY elevated the expression levels of Post synaptic density protein 95 (PSD95) and synaptophysin, and mitigated the loss of dendritic spine density in the hippocampus of APP/PS1 mice. QFY has been shown to ameliorated the structural abnormalities of mitochondria, including mitochondrial dissolution and degradation, up-regulate ATP synthesis and membrane potential in the hippocampus of APP/PS1 mice. Moreover, QFY activated the Keap1/Nrf2/ARE signaling pathway in the hippocampus of APP/PS1 mice, which might contribute to the neuroprotective effects of QFY. CONCLUSION: QFY activates the Keap1/Nrf2/ARE signaling, and protects against synaptic and mitochondrial dysfunction in APP/PS1 mice, proposing a potential alternative therapeutic strategy for AD management.

Pharmacotherapeutic potential of malvidin to cure imidacloprid induced hepatotoxicity via regulating PI3K/AKT, Nrf-2/Keap-1 and NF-κB pathway.

Imidacloprid (IMI) is one of the top-notch insecticides that adversely affects the body organs including the liver. Malvidin (MAL) is a natural flavonoid which exhibits a wide range of pharmacological properties. This research was designed to evaluate the protective ability of MAL to counteract IMI instigated liver toxicity in rats. Thirty-two rats were divided into four groups including control, IMI (5mg/kg), IMI (5mg/kg) + MAL (10mg/kg) and MAL (10mg/kg) alone treated group. The recommended dosages were administrated through oral gavage for 4 weeks. It was revealed that IMI intoxication disrupted the PI3K/AKT and Nrf-2/Keap-1 pathway. Furthermore, the activities of catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD), heme-oxygenase-1 (OH-1) and glutathione reductase (GSR) were reduced while upregulating reactive oxygen species (ROS) and malondialdehyde (MDA) levels after IMI treatment. Moreover, IMI poisoning increased the levels of ALT (Alanine aminotransferase), AST (Aspartate transaminase), and ALP (Alkaline phosphatase) while reducing the levels of total proteins and albumin in hepatic tissues of rats. Besides, IMI administration escalated the expressions of Bcl-2-associated protein x (Bax) and cysteine-aspartic acid protease-3 (Caspase-3) while downregulating the expressions of B-cell lymphoma 2 (Bcl-2). Similarly, IMI intoxication, increased the levels of Interleukin-6 (IL-6), Nuclear factor kappa-B (NF-κB), Interleukin-1ß (IL-1ß), tumor necrosis factor-α (TNF-α), and the activity of cyclooxygenase-2 (COX-2). Furthermore, IMI disrupted the normal architecture of hepatic tissues. However, MAL treatment remarkably protected the liver tissues via regulating abovementioned disruptions.

Armillariella tabescens-derived polysaccharides alleviated â±°-Gal-induced neuroinflammation and cognitive injury through enterocerebral axis and activation of keap-1/Nrf2 pathway.

The early symptoms of neurodegenerative diseases include oxidative stress disorder and accelerated inflammation levels. Edible fungi polysaccharides play essential roles in anti-neuroinflammation. We analyzed the regulatory mechanisms of polysaccharides from extracellular Armillariella tabescens (ATEP) in alleviating neuroinflammation in mice. Mice were induced with d-galactose and aluminum chloride to establish an animal model of Alzheimer's disease, then intragastrically treated with ATEP, which had been previously analyzed for its physicochemical properties. We assessed the critical characteristics of mice treated for neuroinflammation, including cognitive behavior, the anti-inflammatory potential of ATEP in hippocampal pathology and critical protein expression, and changes in fecal microbial composition and metabolites. ATEP intervened in oxidative stress by enhancing antioxidant enzyme activities and suppressing the Keap-1/Nrf2 signaling pathway. Changing the Nrf2 content in the nucleus led to changes in the downstream oxidation-related enzymes, HO-1, NQO-1, iNOS, and COX-2, and the neuronal morphology in CA3 region of the hippocampus. Microbiome analysis revealed that ATEP remodeled the gut microbiotas and regulated the short-chain fatty acids-producing bacteria. Early intervention with ATEP via active dietary supplementation may promote neuroprotection.

Inhibitor of apoptosis stimulating protein of p53 protects against MPP+-induced neurotoxicity of dopaminergic neurons.

Inhibitor of apoptosis stimulating protein of p53 (iASPP) is related to the pathogenesis of several neurological disorders by affecting the oxidative stress and survival of neurons. However, whether iASPP has a role in Parkinson disease (PD) remains to be determined. This work explored the potential regulatory effect of iASPP in an in vitro model of PD based on 1-methyl-4-phenylpyridinium (MPP+)-evoked neurotoxicity of dopaminergic neurons in culture. MN9D neurons were treated with MPP+ at 200 µM in the culture media for 24 h to induce neurotoxicity. Overexpression and silencing of iASPP in neurons were achieved by infecting recombinant adenovirus expressing iASPP and sh-iASPP, respectively. Protein expression was examined by immunoblotting. MPP+-evoked neurotoxicity of dopaminergic neurons was determined by cell viability, TUNEL, and flow cytometric assays. The transcriptional activity of nuclear erythroid factor 2-like 2 (Nrf2) was assessed by luciferase reporter assay. Kelch-like ECH-associated protein 1 (Keap1)-knockout neurons were generated by lentiCRISPR/Cas9-Keap1 constructs. Expression levels of iASPP declined in MPP+-stimulated neurons. Overexpression of iASPP in neurons exhibited inhibitory effects on MPP+-evoked apoptosis, α-synuclein accumulation, and oxidative stress, while iASPP-deficient neurons were more sensitive to MPP+-induced neurotoxicity. Overexpression of iASPP led to an enhancing effect on Nrf2 activation in MPP+-stimulated neurons. Mechanism research revealed that iASPP may contribute to the activation of Nrf2 by competing with Nrf2 in binding with Keap1. Notably, the regulatory effect of iASPP on Nrf2 was diminished in Keap1-knockout neurons. The chemical inhibition of Nrf2 or knockdown of Nrf2 abrogated the protective effects of iASPP on MPP+-induced neurotoxicity. To conclude, iASPP protects dopaminergic neurons against MPP+-induced neurotoxicity through modulation of the Keap1/Nrf2 axis. Therefore, iASPP may play a crucial role in mediating the loss of dopaminergic neurons in PD, and targeting the iASPP-Nrf2 axis could be a promising strategy for treating PD.

Targeting TRIM40 signaling reduces esophagus cancer development: A mechanism involving in protection of oroxylin A.

Oroxylin A (OA), a naturally active O-methylated flavone derived from Scutellaria baicalensis, is regarded as a potential drug with strong anticancer effects. Unfortunately, our understanding of the antineoplastic mechanism of oral exposure to such flavonoids is inadequate. Growing evidence has confirmed the important role of OA in the regulation of oxidative stress- and inflammatory-response-induced tissue injury. However, it remains unknown whether OA is capable of mitigating esophagus cancer (EC) progression and its potential molecular mechanism. Furthermore, the tripartite motif containing 40 (TRIM40) is a ubiquitin ligase that mediates the immune response. The potential molecular function of TRIM40 in regulating EC is largely unknown. We confirmed that OA-triggered oxidative stress markedly upregulates TRIM40. During the OA challenge, increased TRIM40 reduced oxidative stress and promoted the ER stress response. Inversely, deletion of TRIM40 facilitated oxidative stress and blocked cancer cell growth in vivo and in vitro. Mechanistically, in response to OA treatment, TRIM40 directly interacts with Keap1 and promotes ubiquitin-proteasome degradation, thus leading to the promotion of Nrf2 nuclear translocation and its downstream cascade activation, which increases antioxidant defense and cell survival. TRIM40 expression was positively correlated with Nrf2 expression and negatively associated with Keap1 expression in EC xenografts and human specimens. In addition, high TRIM40 expression correlates with poor patient survival in EC. The findings suggested that oral exposure to OA significantly mitigates EC development by targeting TRIM40 activity. These findings further elucidated the potential role of TRIM40 in EC progression by mediating Keap1 degradation, which could be considered a therapeutic target for the treatment of such a disease.