Linagliptin ameliorates tacrolimus-induced renal injury: role of Nrf2/HO-1 and HIF-1α/CTGF/PAI-1.

BACKGROUND: Tacrolimus (TAC) is a frequently used immunosuppressive medication in organ transplantation. However, its nephrotoxic impact limits its long-term usage. This study aims to investigate the effect of linagliptin (Lina) on TAC-induced renal injury and its underlying mechanisms. METHODS AND RESULTS: Thirty-two Sprague Dawley rats were treated with TAC (1.5 mg/kg/day, subcutaneously) and/or Lina (5 mg/kg/day, orally) for 4 weeks. Histological examination was conducted, and serum and urinary biomarkers were measured to assess kidney function and integrity. Furthermore, ELISA, Western blot analysis and immunohistochemical assay were employed to determine signaling molecules of oxidative stress, profibrogenic, hypoxic, and apoptotic proteins. Tacrolimus caused renal dysfunction and histological deterioration evidenced by increased serum creatinine, blood urea nitrogen (BUN), urinary cystatin C, and decreased serum albumin as well as elevated tubular injury and interstitial fibrosis scores. Additionally, TAC significantly increased the expression of collagen type-1, alpha-smooth muscle actin (α-SMA), plasminogen activator inhibitor-1 (PAI-1), and transforming growth factor-beta1 (TGF-ß1) renal content. Moreover, TAC decreased the expression of nuclear factor erythroid-2-related factor2 (Nrf2), heme oxygenase 1 (HO-1), and mitochondrial superoxide dismutase (SOD2). In addition, TAC increased protein expression of hypoxia-inducible factor1-alpha (HIF-1α), connective tissue growth factor (CTGF), inducible nitric oxide synthase (iNOS), 8-hydroxy-2-deoxyguanosine (8-OHdG), as well as nitric oxide (NO), 4-hydroxynonenal, caspase-3 and Bax renal contents. Furthermore, TAC decreased Bcl-2 renal contents. The Lina administration markedly attenuated these alterations. CONCLUSION: Lina ameliorated TAC-induced kidney injury through modulation of oxidative stress, hypoxia, and apoptosis related proteins.

Shizukaol C alleviates trimethylamine oxide-induced inflammation through activating Keap1-Nrf2-GSTpi pathway in vascular smooth muscle cell.

BACKGROUND: Cardiovascular disease is one of the main causes of global mortality, and there is an urgent need for effective treatment strategies. Gut microbiota-dependent metabolite trimethylamine-N-oxide (TMAO) promotes the development of cardiovascular diseases, and shizukaol C, a natural sesquiterpene isolated from Chloranthus multistachys with various biological activities, might exhibit beneficial role in preventing TMAO-induced vascular inflammation. PURPOSE: The purpose of this study was to investigate the anti-inflammatory effects and the underlying mechanisms of shizukaol C on TMAO-induced vascular inflammation. METHODS: The effect and underlying mechanism of shizukaol C on TMAO-induced adhesion molecules expression, bone marrow-derived macrophages (BMDM) adhesion to VSMC were evaluated by western blot, cell adhesion assay, co-immunoprecipitation, immunofluorescence assay, and quantitative Real-Time PCR, respectively. To verify the role of shizukaol C in vivo, TMAO-induced vascular inflammation model were established using guidewire-induced injury on mice carotid artery. Changes in the intima area and the expression of GSTpi, VCAM-1, CD68 were examined using haematoxylin-eosin staining, and immunofluorescence assay. RESULTS: Our data demonstrated that shizukaol C significantly suppressed TMAO-induced adhesion molecule expression and the bone marrow-derived macrophages (BMDM) adhesion in vascular smooth muscle cells (VSMC). Mechanically, shizukaol C inhibited TMAO-induced c-Jun N-terminal kinase (JNK)-nuclear factor-kappa B (NF-κB)/p65 activation, and the JNK inhibition was dependent on the shizukaol C-mediated glutathione-S-transferase pi (GSTpi) expression. By further molecular docking and protein-binding analysis, we demonstrated that shizukaol C directly binds to Keap1 to induce Nrf2 nuclear translocation and upregulated GSTpi expression. Consistently, our in vivo experiment showed that shizukaol C elevated the expression level of GSTpi in carotid arteries and alleviates TMAO-induced vascular inflammation. CONCLUSION: Shizukaol C exerts anti-inflammatory effects in TMAO-treated VSMC by targeting Keap1 and activating Nrf2-GSTpi signaling and resultantly inhibits the downstream JNK-NF-κB/p65 activation and VSMC adhesion, and alleviates TMAO-induced vascular inflammation in vivo, suggesting that shizukaol C may be a potential drug for treating TMAO-induced vascular diseases.

Protective Role of Dioscin against Doxorubicin-Induced Chronic Cardiotoxicity: Insights from Nrf2-GPX4 Axis-Mediated Cardiac Ferroptosis.

Recent evidence suggests that ferroptosis, an iron-facilitated cell death with excessive lipid peroxidation, is a critical mechanism underlying doxorubicin (DOX)-induced cardiotoxicity (DIC). Although dioscin has been reported to improve acute DIC, direct evidence is lacking to clarify the role of dioscin in chronic DIC and its potential mechanism in cardiac ferroptosis. In this study, we used chronic DIC rat models and H9c2 cells to investigate the potential of dioscin to mitigate DIC by inhibiting ferroptosis. Our results suggest that dioscin significantly improves chronic DIC-induced cardiac dysfunction. Meanwhile, it significantly inhibited DOX-induced ferroptosis by reducing Fe2+ and lipid peroxidation accumulation, maintaining mitochondrial integrity, increasing glutathione peroxidase 4 (GPX4) expression, and decreasing acyl-CoA synthetase long-chain family 4 (ACSL4) expression. Through transcriptomic analysis and subsequent validation, we found that the anti-ferroptotic effects of dioscin are achieved by regulating the nuclear factor-erythroid 2-related factor 2 (Nrf2)/GPX4 axis and Nrf2 downstream iron metabolism genes. Dioscin further downregulates nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX4) and upregulates expression of frataxin (FXN) and ATP-binding cassette B8 (ABCB8) to limit mitochondrial Fe2+ and lipid peroxide accumulation. However, Nrf2 inhibition diminishes the anti-ferroptotic effects of dioscin, leading to decreased GPX4 expression and increased lipid peroxidation. This study is a compelling demonstration that dioscin can effectively reduce DIC by inhibiting ferroptosis, which is dependent on the Nrf2/GPX4 pathway modulation.

Neuroprotective role of Carvacrol via Nrf2/HO-1/NLRP3 axis in Rotenone-induced PD mice model.

Parkinson's disease (PD) is a multifactorial neurodegenerative disorder whose cause is unclear. Neuroinflammation is recognized as one of the major pathogenic mechanisms involved in the development and progression of PD. NLRP3 inflammasome is the most widely studied inflammatory mediator in various diseases including PD. Several phytoconstituents have shown neuroprotective role in PD. Carvacrol is a phenolic monoterpene commonly found in the essential oils derived from plants belonging to Lamiaceae family. It is well known for its anti-inflammatory and antioxidant properties and has been widely explored in several diseases. In this study, we explored the role of Carvacrol in suppressing neuroinflammation by regulating NLRP3 inflammasome through Nrf2/HO-1 axis and subsequently, inflammatory cytokines like IL-1ß, IL-18 in Rotenone induced PD mice model. Three doses (25 mg/kg, 50 mg/kg, 100 mg/kg p.o.) of Carvacrol were administered to, respectively, three groups (LD, MD, HD), one hour after administration of Rotenone (1.5 mg/kg, i.p.), every day, for 21 days. Treatment with Carvacrol ameliorated the motor impairment caused by Rotenone. It alleviated neurotoxicity and reduced inflammatory cytokines. Further, Carvacrol also alleviated oxidative stress and increased antioxidant enzymes. From these results, we show that Carvacrol exerts neuroprotective effects in PD via anti-inflammatory and antioxidant mechanisms and could be a potential therapeutic option in PD.

Cinnamaldehyde protects cardiomyocytes from oxygen-glucose deprivation/reoxygenation-induced lipid peroxidation and DNA damage via activating the Nrf2 pathway.

Rapid restoration of perfusion in ischemic myocardium is the most direct and effective treatment for coronary heart disease but may cause myocardial ischemia/reperfusion injury (MIRI). Cinnamaldehyde (CA, C9H8O), a key component in the well-known Chinese medicine cinnamomum cassia, has cardioprotective effects against MIRI. This study aimed to observe the therapeutic effect of CA on MIRI and to elucidate its potential mechanism. H9C2 rat cardiomyocytes were pretreated with CA solution at 0, 10, and 100 µM, respectively and subjected to oxygen-glucose deprivation/reoxygenation (OGD/R). Then the cell viability, the NF-κB and caspase3 gene levels, the reduced glutathione (GSH)/oxidized glutathione (GSSG) ratio, superoxide dismutase (SOD) level, reactive oxygen species (ROS) generation, 4-hydroxynonenal (4-HNE), and malondialdehyde (MDA) were detected. The severity of DNA damage was assessed by tail moment (TM) values using alkaline comet assay. Besides, the DNA damage-related proteins and the key proteins of the Nrf2 pathway were detected by western blot. CA treatment increased the cell viability, GHS/GSSG ratio, SOD level, PARP1, Nrf2, PPAR-γ, and HO-1 protein levels of H9C2 cardiomyocytes, while reducing NF-κB, caspase3, ROS level, 4-HNE and MDA content, γ-H2AX protein level, and TM values. Inhibition of the Nrf2 pathway reversed the effect of CA on cell viability and apoptosis of OGD/R induced H9C2 cardiomyocytes. Besides, 100 µM CA was more effective than 10 µM CA. In the OGD/R-induced H9C2 cardiomyocyte model, CA can protect cardiomyocytes from MIRI by attenuating lipid peroxidation and repairing DNA damage. The mechanism may be related to the activation of the Nrf2 pathway.

Baicalin inhibits IL-1ß-induced ferroptosis in human osteoarthritis chondrocytes by activating Nrf-2 signaling pathway.

BACKGROUND: Osteoarthritis (OA) is a common degenerative disease involving articular cartilage, in which ferroptosis of chondrocytes plays an important role. Baicalin (BAI) exerts regulatory effects in a wide range of orthopedic diseases including OA, but its effect on ferroptosis of chondrocytes (CHs) is still unclear. The purpose of this study was to determine the effect of BAI on ferroptosis in human OA chondrocytes (OACs), and to explore its possible mechanism. METHODS: CHs were treated with IL-1ß (10 ng/mL) to simulate inflammation in vitro. Immunofluorescence, quantitative RT-PCR, Western blotting and cell viability assay were performed to evaluate the impacts of BAI on Fe2+ level, mitochondrial dysfunction, ferroptosis-related proteins, oxidative stress and cytotoxicity in CHs. Additionally, siRNA was made use of to knock out nuclear factor E2-related factor 2 (Nrf2) to analyze the role played by Nrf2 in BAI-induced CH ferroptosis. RESULTS: BAI eliminated IL-1ß-induced Fe2+ accumulation, changes in mitochondrial membrane potential and ferroptosis-related protein GPX4, SLC7A11, P53 and ACSL4 levels, as well as reactive oxygen species (ROS), lipid peroxidation (LPO) and malondialdehyde (MDA) accumulation in CHs. Besides, BAI reversed IL-1ß-induced decrease of Collagen II and increase of MMP13 in CHs. Meanwhile, BAI attenuated IL-1ß-induced CH toxicity and promoted Nrf2 antioxidant system activation. When Nrf2 was knocked down by siRNA, the effects of BAI on IL-1ß-induced ferroptosis-related proteins and antioxidant stress in CHs were significantly weakened. CONCLUSIONS: This study demonstrates that IL-1ß can induce CH ferroptosis. BAI is able to inhibit IL-1ß-induced CH ferroptosis and ECM degradation, and the specific mechanism may be that it can inhibit IL-1ß-induced CH ferroptosis by activating Nrf2 antioxidant system to attenuate the accumulation of intracellular ROS and lipid ROS.

Xanthohumol attenuates collagen synthesis in scleroderma skin fibroblasts by ROS/Nrf2/TGFß1/Smad3 pathway.

Skin fibrosis, the most obvious clinical manifestation of systemic sclerosis (SSc), has a high unmet need for treatment. Xanthohumol (Xn) has been shown to have beneficial effects on fibrotic diseases, but its efficacy in SSc remains unreported. This study aims to elucidate the effects and mechanisms of Xn on collagen synthesis in SSc skin fibroblasts (SScF). We found increased collagen production in SScF cultured in vitro, accompanied by dysregulated levels of oxidative stress. Cell experiments showed that Xn inhibited cell proliferation and promoted apoptosis. In addition, Xn was shown for the first time to upregulate reactive oxygen species (ROS) and nuclear factor erythroid 2-related factor 2 (Nrf2)levels in SScF, and when combined with the ROS scavenger N-acetylcysteine (NAC), Nrf2 expression was decreased. Importantly, we demonstrated that Xn significantly attenuated collagen synthesis by blocking the fibrotic classical transforming growth factor beta 1 (TGFß1)/Smad3 pathway, which interestingly was upregulated when combined with the Nrf2 inhibitor 385. Taken together, Xn suppressed the TGFß1/Smad3 pathway to ameliorate collagen overproduction by promoting ROS-induced oxidative stress damage and activating Nrf2, suggesting that Xn administration may be an emerging therapeutic strategy for skin fibrosis in SSc.

Mitigative potential of kaempferide against polyethylene microplastics induced testicular damage by activating Nrf-2/Keap-1 pathway.

Polyethylene microplastics (PE-MPs) are one of the environmental contaminants that instigate oxidative stress (OS) in various organs of the body, including testes. Kaempferide (KFD) is a plant-derived natural flavonol with potential neuroprotective, hepatoprotective, anti-cancer, anti-oxidant and anti-inflammatory properties. Therefore, the present study was designed to evaluate the alleviative effects of KFD against PE-MPs-prompted testicular toxicity in rats. Fourty eight adult male albino rats were randomly distributed into 4 groups: control, PE-MPs-administered (1.5 mgkg-1), PE-MPs (1.5 mgkg-1) + KFD (20 mgkg-1) co-treated and KFD (20 mgkg-1) only treated group. PE-MPs intoxication significantly (P < 0.05) lowered the expression of Nrf-2 and anti-oxidant enzymes, while increasing the expression of Keap-1. The activities of anti-oxidants i.e., catalase (CAT), glutathione reductase (GSR), superoxide dismutase (SOD), hemeoxygene-1 (HO-1) and glutathione peroxidase (GPx) were reduced, besides malondialdehyde (MDA) and reactive oxygen species (ROS) contents were increased significantly (P < 0.05) following the PE-MPs exposure. Moreover, PE-MPs exposure significantly (P < 0.05) reduced the sperm motility, viability and count, whereas considerably (P < 0.05) increased the dead sperm number and sperm structural anomalies. Furthermore, PE-MPs remarkably (P < 0.05) decreased steroidogenic enzymes and Bcl-2 expression, while increasing the expression of Caspase-3 and Bax. PE-MPs exposure significantly (P < 0.05) reduced the levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH) and testosterone, whereas inflammatory indices were increased. PE-MPs exposure also induced significant histopathological damages in the testes. Nevertheless, KFD supplementation significantly (P < 0.05) abrogated all the damages induced by PE-MPs. The findings of our study demonstrated that KFD could significantly attenuate PE-MPs-instigated OS and testicular toxicity, due to its anti-oxidant, anti-inflammatory, androgenic and anti-apoptotic potential.

A combination of isoliquiritigenin with Artemisia argyi and Ohwia caudata water extracts attenuates oxidative stress, inflammation, and apoptosis by modulating Nrf2/Ho-1 signaling pathways in SD rats with doxorubicin-induced acute cardiotoxicity.

Ohwia caudata (Thunb.) H. Ohashi (Leguminosae) also called as "Evergreen shrub" and Artemisia argyi H.Lév. and Vaniot (Compositae) also named as "Chinese mugwort" those two-leaf extracts frequently used as herbal medicine, especially in south east Asia and eastern Asia. Anthracyclines such as doxorubicin (DOX) are commonly used as effective chemotherapeutic drugs in anticancer therapy around the world. However, chemotherapy-induced cardiotoxicity, dilated cardiomyopathy, and congestive heart failure are seen in patients who receive DOX therapy, with the mechanisms underlying DOX-induced cardiac toxicity remaining unclear. Mitochondrial dysfunction, oxidative stress, inflammatory response, and cardiomyocytes have been shown to play crucial roles in DOX-induced cardiotoxicity. Isoliquiritigenin (ISL, 10 mg/kg) is a bioactive flavonoid compound with protective effects against inflammation, neurodegeneration, cancer, and diabetes. Here, in this study, our aim is to find out the Artemisia argyi (AA) and Ohwia caudata (OC) leaf extract combination with Isoliquiritigenin in potentiating and complementing effect against chemo drug side effect to ameliorate cardiac damage and improve the cardiac function. In this study, we showed that a combination of low (AA 300 mg/kg; OC 100 mg/kg) and high-dose(AA 600 mg/kg; OC 300 mg/kg) AA and OC water extract with ISL activated the cell survival-related AKT/PI3K signaling pathway in DOX-treated cardiac tissue leading to the upregulation of the antioxidant markers SOD, HO-1, and Keap-1 and regulated mitochondrial dysfunction through the Nrf2 signaling pathway. Moreover, the water extract of AA and OC with ISL inhibited the inflammatory response genes IL-6 and IL-1ß, possibly through the NFκB/AKT/PI3K/p38α/NRLP3 signaling pathways. The water extract of AA and OC with ISL could be a potential herbal drug treatment for cardiac hypertrophy, inflammatory disease, and apoptosis, which can lead to sudden heart failure.

Panax quinquefolius saponin inhibits vascular smooth muscle cell calcification via activation of nuclear factor-erythroid 2-related factor 2.

BACKGROUND: Panax quinquefolius saponin (PQS) is the main active component of Panax quinquefolius. Emerging evidence suggests that PQS exerts beneficial effects against cardiovascular diseases. However, the role and mechanism of PQS in vascular calcification are not unclear. The present study investigated the effects of PQS on the calcification of vascular smooth muscle cell (VSMCs). METHODS: The present study used calcification medium containing 3 mM inorganic phosphate (Pi) to induce rat VSMCs calcification. We investigated the effects of PQS on VSMCs calcification using alizarin red staining and alkaline phosphatase (ALP) activity assays. The intracellular reactive oxygen species (ROS) levels and the transcriptional activity of nuclear factor-erythroid 2-related factor 2 (Nrf2) were determined. The mRNA and protein expression levels of Nrf2, the antioxidant gene heme oxygenase-1 (HO-1), osteogenic markers, including runt-related transcription factor 2 (Runx2) and bone morphogenetic protein 2 (BMP2), and Kelch-like ECH-associated protein 1 (Keap1) were also measured. RESULTS: Treatment with Pi significantly increased intracellular calcium deposition and ALP activity, which were suppressed by PQS in a concentration-dependent manner. During VSMCs calcification, PQS inhibited the mRNA and protein expression of Runx2 and BMP2. PQS treatment reduced intracellular ROS production and significantly upregulated Nrf2 transcriptional activity and the expression of Nrf2 and its target antioxidant gene HO-1. PQS suppressed the Pi-induced protein expression of Keap1, which is an endogenous inhibitor of Nrf2. Keap1 siRNA treatment induced Nrf2 expression and downregulated Runx2 expression in the presence of Pi and PQS. CONCLUSION: Taken together, these findings suggest that PQS could effectively inhibit VSMCs calcification by ameliorating oxidative stress and regulating osteogenic genes via the promotion of Nrf2 expression.

Gastrodin programs an Arg-1+ microglial phenotype in hippocampus to ameliorate depression- and anxiety-like behaviors via the Nrf2 pathway in mice.

BACKGROUND: Regulating the microglial phenotype is an attractive strategy for treating diseases of the central nervous system such as depression and anxiety. Gastrodin can quickly cross the blood-brain barrier and mitigate microglia-mediated inflammation, which widely used to treat a variety of central nervous system diseases associated with microglial dysfunction. However, the molecular mechanism by which gastrodin regulates the functional phenotype of microglia remains unclear. PURPOSE: Since the transcription factor "nuclear factor erythroid 2-related factor 2″ (Nrf2) is associated with the anti-inflammatory effects of gastrodin, we hypothesized that gastrodin induces Nrf2 expression in microglia and thereby programs an anti-inflammatory phenotype. STUDY DESIGN: Male C57BL/6 mice, treated or not with gastrodin, were given lipopolysaccharide (LPS) at 0.25 mg/kg/d for 10 days to induce chronic neuroinflammation. The effects of gastrodin on microglial phenotypes, neuroinflammation and depression- and anxiety-like behaviors were evaluated. In another experiment, animals were treated with Nrf2 inhibitor ML385 throughout the 13-day gastrodin intervention period. METHODS: The effects of gastrodin on depression- and anxiety-like behaviors were evaluated through the sucrose preference test, forced swimming test, open field test and elevated plus-maze test; as well as its effects on morphology and molecular and functional phenotypes of hippocampal microglia through immunohistochemistry, real-time PCR and enzyme-linked immunosorbent assays. RESULTS: Chronic exposure to LPS caused hippocampal microglia to secrete inflammatory cytokines, their somata to enlarge, and their dendrites to lose branches. These changes were associated with depression- and anxiety-like behaviors. Gastrodin blocked these LPS-induced alterations and promoted an Arg-1+ microglial phenotype that protected neurons from injury. The effects of gastrodin were associated with Nrf2 activation, whereas blockade of Nrf2 antagonized gastrodin. CONCLUSION: These results suggest that gastrodin acts via Nrf2 to promote an Arg-1+ microglial phenotype, which buffers the harmful effects of LPS-induced neuroinflammation. Gastrodin may be a promising drug against central nervous system diseases that involve microglial dysfunction.

Natural Products as Modulators of Nrf2 Signaling Pathway in Neuroprotection.

Neurodegenerative diseases (NDs) affect the West due to the increase in life expectancy. Nervous cells accumulate oxidative damage, which is one of the factors that triggers and accelerates neurodegeneration. However, cells have mechanisms that scavenge reactive oxygen species (ROS) and alleviate oxidative stress (OS). Many of these endogenous antioxidant systems are regulated at the gene expression level by the transcription factor Nrf2 (nuclear factor erythroid 2-related factor 2). In the presence of prooxidant conditions, Nrf2 translocates to the nucleus and induces the transcription of genes containing ARE (antioxidant response element). In recent years, there has been an increase in the study of the Nrf2 pathway and the natural products that positively regulate it to reduce oxidative damage to the nervous system, both in in vitro models with neurons and microglia subjected to stress factors and in vivo models using mainly murine models. Quercetin, curcumin, anthocyanins, tea polyphenols, and other less studied phenolic compounds such as kaempferol, hesperetin, and icariin can also modulate Nrf2 by regulating several Nrf2 upstream activators. Another group of phytochemical compounds that upregulate this pathway are terpenoids, including monoterpenes (aucubin, catapol), diterpenes (ginkgolides), triterpenes (ginsenosides), and carotenoids (astaxanthin, lycopene). This review aims to update the knowledge on the influence of secondary metabolites of health interest on the activation of the Nrf2 pathway and their potential as treatments for NDs.

Hesperidin methylchalcone (HMC) hinders amyloid-ß induced Alzheimer's disease by attenuating cholinesterase activity, macromolecular damages, oxidative stress and apoptosis via regulating NF-κB and Nrf2/HO-1 pathways.

Phytocompounds therapy has recently emerged as an effective strategy to treat Alzheimer's disease. Herein, the protective effect of hesperidin methylchalcone (HMC) was evaluated through Alzheimer's disease models of Neuro-2a cells and Wistar rats. The in vitro results showed that HMC possesses significant ability to inhibit the acetylcholinesterase enzyme and exhibiting anti-aggregation and disaggregation properties. Furthermore, HMC could protect the Neuro-2a cells against Aß-induced neurotoxicity. Simultaneously, HMC treatment significantly improved the cognitive deficits caused by Aß-peptide on spatial memory in Wistar rats. HMC significantly enhanced the cholinergic effects by inhibiting AChE, BuChE, ß-secretase activity, caspase-3 activity, and attenuating macromolecular damages and apoptosis. Notably, HMC reduced the Aß-induced oxidative stress by activating the antioxidative defence enzymes. In addition, the HMC treatment suppressed the expression of immunocytokines such as p-NF-κB p65, p-IκBα, induced by Aß; whereas upregulating Nrf2, HO-1 in brain homogenate. These results suggest that HMC could attenuate Aß-induced neuroinflammation in brain via suppressing NF-κB signalling pathway and activating the Nrf2/HO-1 pathway, thereby improving memory and cognitive impairments in Wistar rats. Overall, the present study reports that HMC can act as a potent candidate with multi-faceted neuroprotective potential against Aß-induced memory dysfunction in Wistar rats for the treatment of Alzheimer's disease.

Alantolactone inhibits oesophageal adenocarcinoma cells through nuclear factor erythroid 2-related factor 2-mediated reactive oxygen species increment.

BACKGROUND: Oesophageal adenocarcinoma (EAC) is a highly lethal cancer associated with a rapidly rising incidence and a poor prognosis. Alantolactone, a sesquiterpene lactone isolated from inula helenium, has anti-inflammatory, antimicrobial, neuroprotective activities, and anticancer properties. OBJECTIVE: In the present study, the anticancer effects of alantolactone on the human EAC cells were investigated in vitro and in vivo. METHODS AND FINDINGS: After treated with alantolactone, the cell viability of KYAE-1, KYAE-2, OE19, and OE33 cells reduced significantly compared with that of the control cells. Alantolactone induced apoptosis of the EAC cell lines by inhibiting the protein expression levels of nuclear factor erythroid2-related factor 2 (Nrf2). Furthermore, the apoptosis-inducing effect of alantolactone was enhanced by Nrf2 knockdown while reduced by overexpression of Nrf2. Antioxidant α-tocopherol and glutathione can protect EAC cell lines against alantolactone. A xenograft nude mice model showed that alantolactone can inhibit EAC growth in vivo. CONCLUSIONS: Alantolactone inhibits oesophageal adenocarcinoma cells through Nrf2-mediated reactive oxygen species (ROS) increment. Alantolactone maybe a potential therapeutical candidate for treating EAC.

Rosmarinic acid mitigates chlorpyrifos-induced oxidative stress, inflammation, and kidney injury in rats by modulating SIRT1 and Nrf2/HO-1 signaling.

Chlorpyrifos (CPF) is a widely used broad-spectrum pesticide with multi-organ toxic effects. Oxidative stress was found to play a role in the deleterious effects of CPF, including nephrotoxicity. This study investigated the protective effect of the antioxidant polyphenol rosmarinic acid (RA) against CPF-induced kidney injury, with an emphasis on oxidative injury, inflammation, SIRT1, and Nrf2/HO-1 signaling. Rats received 10 mg/kg CPF and 25, 50, and 100 mg/kg RA orally for 28 days, and the samples were collected for analysis. CPF increased serum urea and creatinine and kidney Kim-1 and caused several histopathological alterations. ROS, MDA, NO, NF-κB p65, TNF-α, and IL-1ß were elevated in the kidney of CPF-intoxicated rats. RA ameliorated kidney function markers, prevented tissue injury, suppressed ROS, MDA, and NO, and downregulated NF-κB p65, TNF-α, and IL-1ß in CPF-intoxicated rats in a dose-dependent manner. RA decreased Bax, caspase-3, oxidative DNA damage, and Keap1, boosted antioxidant enzymes and Bcl-2, and upregulated Nrf2, HO-1, and SIRT1 in CPF-administered rats. Molecular docking simulation revealed the binding affinity of RA toward NF-κB, Keap1, HO-1, and SIRT1. In conclusion, RA prevented CPF nephrotoxicity by attenuating oxidative stress, inflammation, and apoptosis and upregulating SIRT1 and Nrf2/HO-1 signaling.

Curcumin alleviates ketamine-induced oxidative stress and apoptosis via Nrf2 signaling pathway in rats' cerebral cortex and hippocampus.

AIMS: To investigate curcumin's protective effect on nerve damage caused by ketamine anesthesia via the Nrf2 signaling pathway. Rats and PC12 cells were used in this experiment to investigate the mechanism of nerve injury caused by ketamine anesthesia. Furthermore, our findings suggest that curcumin may affect oxidative stress and apoptosis by targeting the Nrf2 pathway, thereby alleviating the nerve injury caused by ketamine. METHODS: The rat cerebral cortex and hippocampus were stained with Nissl and immunohistochemistry to determine the number of neurons and the expression of Caspase-3, Bcl-2, and Bax. CCK-8 assay was used to determine the optimal concentration of ketamine, curcumin, and H2 O2 in PC12 cells. Flow cytometry was used to detect changes in reactive oxygen species and the rate of apoptosis in each group. To determine whether Nrf2 entered the nucleus, immunofluorescence was used. Both tissues and cells were subjected to RT-PCR and Western blotting detection at the same time. The levels of oxidative stress were determined using a malondialdehyde (MDA) and superoxide dismutase (SOD) assay kit. RESULTS: Ketamine reduced the number of neurons in the cortex and hippocampus of rats. The proteins Bax and Caspase-3 were upregulated, while Bcl-2 was down-regulated in the cortex and hippocampus. The viability of PC12 cells has decreased. MDA content increased while SOD activity decreased in cortex, hippocampus, and PC12 cells. Ketamine had an effect on the expression of some genes in the Nrf2 signaling pathway as well as apoptosis. Curcumin pretreatment may be able to prevent ketamine-induced damage. CONCLUSIONS: The oxidative stress and apoptosis caused by ketamine during growth of the cerebral cortex, hippocampus, and PC12 cells may be decreased by curcumin's activation of the Nrf2 signaling pathway. Our research provides a potential strategy for the secure administration of anesthetics in medical settings.

Melatonin ameliorates bleomycin-induced pulmonary fibrosis via activating NRF2 and inhibiting galectin-3 expression.

Pulmonary fibrosis (PF) is a chronic interstitial lung disease with no effective therapies. Galectin-3 (Gal-3), a marker of oxidative stress, plays a key role in the pathogenesis of PF. Fibroblast-myofibroblast differentiation (FMD) is an important source of fibrotic cells in PF. Previous studies showed that melatonin (MT) exerted anti-fibrotic effect in many diseases including PF through its antioxidant activity. In the present study we investigated the relationships among Gal-3, NRF2, ROS in FMD and their regulation by MT. We established an in vitro model of FMD in TGF-ß1-treated human fetal lung fibroblast1 (HFL1) cells and a PF mouse model via bleomycin (BLM) intratracheal instillation. We found that Gal-3 expression was significantly increased both in vitro and in vivo. Knockdown of Gal-3 in HFL1 cells markedly attenuated TGF-ß1-induced FMD process and ROS accumulation. In TGF-ß1-treated HFL1 cells, pretreatment with NRF2-specific inhibitor ML385 (5 µM) significantly increased the levels of Gal-3, α-SMA and ROS, suggesting that the expression of Gal-3 was regulated by NRF2. Treatment with NRF2-activator MT (250 µM) blocked α-SMA and ROS accumulation accompanied by reduced Gal-3 expression. In BLM-induced PF model, administration of MT (5 mg·kg-1·d-1, ip for 14 or 28 days) significantly attenuated the progression of lung fibrosis through up-regulating NRF2 and down-regulating Gal-3 expression in lung tissues. These results suggest that Gal-3 regulates TGF-ß1-induced pro-fibrogenic responses and ROS production in FMD, and MT activates NRF2 to block FMD process by down-regulating Gal-3 expression. This study provides a useful clue for a clinical strategy to prevent PF. Graphic abstract of the mechanisms. MT attenuated BLM-induced PF via activating NRF2 and inhibiting Gal-3 expression.

The synthesis of novel thioderivative chalcones and their influence on NF-κB, STAT3 and NRF2 signaling pathways in colorectal cancer cells.

This study aimed to synthesize new thioderivative chalcones and analyze their impact on the NF-κB, STAT3, EGFR and Nrf2 signaling pathways in colorectal cancer cells. Among the studied compounds, derivatives 4 and 5 decreased the activation of NF-κB and the expression of the target gene COX-2. In the case of STAT3, we observed the inhibition of activation of this signaling pathway after influencing derivative 4. Increased activation of the Nrf2 signaling pathway was demonstrated for derivatives 5 and 7 in DLD-1 and HCT116 cells. The results of this study indicated that new chalcone derivatives, especially compounds 4, 5, and-to some degree-7, possess potential applications in the prevention of colorectal cancer.

Carveol Promotes Nrf2 Contribution in Depressive Disorders through an Anti-inflammatory Mechanism.

Major depressive disorder (MDD) is a progressive deteriorating mental state with a feeling of worthlessness and frequent mood swings. Several studies reported the favorable effects of natural drug substances on MMD associated oxidative stress and neuroinflammation. The present study is attempted to examine whether carveol could affect lipopolysaccharide- (LPS-) induced depression, and if so, how nuclear factor E2-related factor (Nrf2) contributed to the neuroprotective effects of carveol mechanistically. Two experimental cohorts were used using the SD rats: first to evaluate the promising dose of carveol (whether 20 mg/kg or 50 mg/kg) and secondly to determine the effect of carveol on Nrf2-mediated antidepression. Significant neuronal alterations were noticed in the cortex and hippocampus regions in the LPS-treated group, accompanied by elevated inflammatory cytokine levels such as tumor necrosis factor-alpha (TNF-α), cyclooxygenase (COX-2), and c-Jun N-terminal kinase (p-JNK). Moreover, amassing of free radicals exacerbated lipid peroxidase (LPO) and oxidative stress with a limited antioxidant capacity. Carveol (20 mg/kg) significantly ameliorated these detrimental effects by promoting the antioxidant Nrf2 gene and protein, which critically regulate the downstream antioxidant and anti-inflammatory pathway. To further elaborate our hypothesis, we employed all-trans retinoic acid (ATRA), an Nrf2 inhibitor, and we found that ATRA exaggerated LPS-induced depressive-like effects associated with elevated neuroinflammatory markers. Our results demonstrated that carveol (20 mg/kg) could activate the endogenous antioxidant Nrf2, which regulates the downstream antioxidant signaling pathway, eventually leading to amelioration of LPS-induced neuroinflammation and neurodegeneration.

Protective effect of rosuvastatin pretreatment against acute myocardial injury by regulating Nrf2, Bcl-2/Bax, iNOS, and TNF-α expressions affecting oxidative/nitrosative stress and inflammation.

Cardiovascular disorders are the leading cause of death globally. Rosuvastatin is a member of statins (inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase) with many pleiotropic properties. This study investigated cardioprotective effects of rosuvastatin in isoprenaline-induced myocardial injury. Male rats were given rosuvastatin (1, 5, or 10 mg/kg, oral) daily for 1 week and on seventh and eighth day isoprenaline (150 mg/kg, subcutaneous) was given to induce cardiac injury. On ninth day, rats were euthanized and different samples were harvested for analysis. Isoprenaline administration resulted in increased cardiac mass, increased cardiac injury marker levels (cTnI, CK-MB, ALT, and AST), increased lipid/protein oxidation, and increased cardiac nitrite levels. It also decreased superoxide dismutase, CAT, GST, and glutathione reductase activities, and total antioxidant activity. Isoprenaline also increased TNF-α and IL-6 levels. Decreased mRNA expression of Nrf2 and Bcl-2 along with increased mRNA expression of Bax, eNOS and iNOS genes was observed in isoprenaline treated animals. Histopathological evaluations of rosuvastatin pre-treated groups showed reduction of myocardial necrosis. Pretreatment with rosuvastatin (5 and 10 mg/kg) reduced many of these pathological changes. The current study showed that rosuvastatin significantly reduces myocardial injury induced by isoprenaline.