Oxidative Stress In Lung Tissue Research Articles

Combined Treatment with Tauroursodeoxycholic Acid and SCD Probiotics Reduces Oxidative Stress in Lung Tissue of Aged Rats

Aging is associated with an increased level of oxidative stress, resulting from an elevated production of reactive oxygen species, which can lead to cellular and tissue damage, particularly in the lungs. This study examined the effects of Tauroursodeoxycholic acid (TUDCA) and SCD Probiotics, both individually and in combination, on oxidative stress markers in the lung tissue of aged Sprague-Dawley rats. The primary objective was to assess the potential of these agents in reducing malondialdehyde (MDA), advanced oxidation protein products (AOPP), and myeloperoxidase (MPO) levels, which are indicative of oxidative damage and inflammation. The results showed that TUDCA significantly decreased MDA and AOPP levels, suggesting its role in maintaining mitochondrial stability and inhibiting apoptotic pathways. SCD Probiotics also demonstrated a reduction in AOPP levels, highlighting their immunomodulatory and antioxidant effects. Furthermore, the combined treatment of TUDCA and SCD Probiotics led to a more pronounced decrease in both MDA and AOPP levels, along with a significant reduction in MPO activity. This suggests a synergistic interaction that enhances the antioxidative and anti-inflammatory properties of the individual treatments. These findings support the therapeutic potential of TUDCA and SCD Probiotics in mitigating oxidative damage in aging lung tissues, proposing that their concurrent use could be an effective strategy against age-related oxidative stress. Further research is warranted to explore these effects across different models and long-term applications.

A novel Saclayvirus Acinetobacter baumannii phage genomic analysis and effectiveness in preventing pneumonia

Acinetobacter baumannii, which is resistant to multiple drugs, is an opportunistic pathogen responsible for severe nosocomial infections. With no antibiotics available, phages have obtained clinical attention. However, since immunocompromised patients are often susceptible to infection, the appropriate timing of administration is particularly important. During this research, we obtained a lytic phage vB_AbaM_P1 that specifically targets A. baumannii. We then assessed its potential as a prophylactic treatment for lung infections caused by clinical strains. The virus experiences a period of inactivity lasting 30 min and produces approximately 788 particles during an outbreak. Transmission electron microscopy shows that vB_AbaM_P1 was similar to the Saclayvirus. Based on the analysis of high-throughput sequencing and bioinformatics, vB_AbaM_P1 consists of 107537 bases with a G + C content of 37.68%. It contains a total of 177 open reading frames and 14 tRNAs. No antibiotic genes were detected. In vivo experiments, using a cyclophosphamide-induced neutrophil deficiency model, tested the protective effect of phage on neutrophil-deficient rats by prophylactic application of phage. The use of phages resulted in a decrease in rat mortality caused by A. baumannii and a reduction in the bacterial burden in the lungs. Histologic examination of lung tissue revealed a decrease in the presence of immune cells. The presence of phage vB_AbaM_P1 had a notable impact on preventing A. baumannii infection, as evidenced by the decrease in oxidative stress in lung tissue and cytokine levels in serum. Our research offers more robust evidence for the early utilization of bacteriophages to mitigate A. baumannii infection.Key points•A novel Saclayvirus phage infecting A. baumannii was isolated from sewage.•The whole genome was determined, analyzed, and compared to other phages.•Assaying the effect of phage in preventing infection in neutrophil-deficient models.

Dynamics of Inflammatory and Pathological Changes Induced by Single Exposure of Particulate Matter (PM2.5) in Mice: Potential Implications in COPD.

Chronic Obstructive Pulmonary Disease (COPD) is a progressive disorder of lungs marked by chronic bronchitis and emphysema. Particulate matter (PM2.5), a major component of air pollution has been correlated with COPD incidence. The present work aimed to understand dynamics of cellular/molecular players behind PM2.5-mediated COPD pathogenesis in mice by conducting dose and time-course studies. Single intratracheal exposure of PM2.5 at a dose of either 100 or 200 μg induced inflammatory response in lungs at 4 days. Time course studies showed that inflammation once triggered by PM2.5 is progressive in nature as reflected by data on BALF inflammatory cells at 7/14 days. Similarly, various cytokines/chemokines (KC/IL-6/TNF-α/IL-1β/G-CSF/MCP-1) peak at either 7 or 14 days. However, inflammation declined sharply at 21 days. Data on LPO/GSH and activities of SOD/Catalase show induction of continuous oxidative stress in lung tissue. Next, enhanced mtROS in the CD11b+ inflammatory cells confirms the redox imbalance in neutrophils/macrophages. A continuous decline in lung function was observed till 28 days. Further, histological analysis of lung tissues at 28 days confirmed the presence of emphysematous lesions, validating the potency of PM2.5 to cause irreversible damage to lungs through complex interplay of various cellular/molecular players which may be exploited as potential preventive/therapeutic targets.

Antioxidant Activity of Baby Java Citrus Peel Extract Promotes Lung Tissue Repair in Mice Challenged by Lipopolysaccharides

Acute lung injury tends to be induced by infection or sepsis that disrupts alveolar and vascular permeability, neutrophil influx, and edema. Those impairments are worsened by the increase of oxidative stress along with hyperinflammation response. Oxidative stress in lung tissue could be indicated by malondialdehyde (MDA) and nuclear fac-tor erythroid 2-related factor 2 (Nrf2) expression. This research aimed to evaluate the efficacy of Baby Java citrus peel extract (BJE) in suppressing oxidative stress and preventing lung injury in lipopolysaccharides (LPS)-induced mice. Twenty-five male BALB/c mice were divided into five groups consisting of untreated (N), LPS (A), and LPS-induced followed by treatment using BJE at various doses: 75 mg/kg BW (BJE-1), 105 mg/kg BW (BJE-2), and 150 mg/kg BW (BJE-3). Lungs were isolated for histopathological analysis also detection of MDA and Nrf2 using flow cytometry. BJE at the dose of 105 mg/kg BW could inhibit the alteration of lung histology following LPS challenge including alveolar and interstitial neutrophil infiltration, proteinaceous debris, and septal thickening. The same dose also showed good potency in suppressing MDA and Nrf2 levels as oxidative stress indicators. Our findings demonstrated the protective effects of Baby Java citrus peel in acute lung injury and oxidative stress prevention after LPS exposure

Protective Effects of Tunisian Orange Co-Product Extract and Oleuropein-Hesperidin Combination on Bleomycin-Induced Pulmonary Fibrosis in Rats.

Idiopathic pulmonary fibrosis (IPF) is a chronic interstitial pneumonia that leads to acute lung damage, deterioration of lung function, and increased mortality risk. In this study, we investigated the effects of the orange coproduct extract (OCE) and the combination of pure hesperidin and oleuropein (HO) on an experimental model of pulmonary fibrosis induced by bleomycin (BLM) in Wistar rats. Rats were divided into six groups: the control group (G1), the BLM group (G2), three groups (G3, G4, G5) receiving a single dose of BLM combined with OCE extract at 100, 200, and 300 mg/kg, and group 6 (G6) receiving a single dose of BLM combined with HO: both pure major phenolic compounds of OCE (hesperidin at 50 mg/kg) and olive leaves (oleuropein at 2.5 mg/kg). Oxidative stress in lung tissues was investigated using catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPX) assays and the measurement of malondialdehyde (MDA) and lactate dehydrogenase (LDH) levels. Treatment with OCE and HO normalized the disturbance in oxidative markers' levels and showed a significant reduction in fibrosis score with no renal or hepatic toxic effects. In conclusion, OCE and HO exhibit antifibrotic effects on a rat model of pulmonary fibrosis.

Triptolide‐Loaded Mesenchymal Stem Cell–Derived Exosomes Ameliorates Lipopolysaccharide‐Induced Acute Lung Injury via Induction of Nrf‐2/HO‐1 Signaling Pathway–Dependent Autophagy and Mitigation of MAPK Signaling Pathway

Acute lung injury (ALI) is a severe disease characterized by a pulmonary inflammatory response and oxidative stress. Triptolide has been demonstrated to have anti‐inflammatory and antioxidant properties. Herein, we present triptolide‐loaded mesenchymal stem cell–derived exosomes (MSC‐Exos) as a multifunctional biomimetic delivery system (Tri‐Exos) for targeting injured lung tissue. The therapeutic effect of Tri‐Exos on ALI was evaluated by measuring inflammatory cytokines content, the expression of myeloperoxidase (MPO), the number of immune cells in bronchoalveolar lavage fluid, malondialdehyde (MDA) content, and superoxide dismutase (SOD) activity. Subsequently, immunohistochemistry and Western blotting were used to assess the expression levels of critical proteins in the nuclear factor erythroid 2‐related factor 2 (Nrf‐2) signaling pathway, autophagy pathway, apoptosis, and MAPK signaling pathway. The experimental results showed that LPS significantly increased pathological damage, secretion of inflammatory cytokines, and oxidative stress in lung tissue. However, treatment with Tri‐Exos significantly alleviated this series of pathological changes. Tri‐Exos significantly upregulated the expression of Nrf‐2 signaling pathway–related proteins, autophagy, and apoptosis and inhibited the expression of MAPK signaling pathway‐related proteins in the ALI model. Our study showed that Tri‐Exos exerted a therapeutic effect on LPS‐induced ALI by regulating the Nrf‐2 signaling pathway–dependent autophagy and MAPK signaling pathway.

Amelioration of Oxidative Stress in Rats with Chronic Obstructive Pulmonary Disease through Shenqi Huatan Decoction Activation of Peroxisome Proliferator‐Activated Receptor Gamma‐Mediated Activated Protein Kinase/Forkhead Transcription Factor O3a Signaling Pathway

Background. Chronic obstructive pulmonary disease (COPD) is a common respiratory disease. Currently, no specific treatment strategy has been established; therefore, finding new treatment methods is essential. Clinically, Shenqi Huatan Decoction (SQHT) is a traditional Chinese medicinal formula for COPD treatment; however, its mechanism of action in treatment needs to be clarified. Methods. The COPD rat model was replicated by cigarette smoking and tracheal injection using the LPS method. The control group and the SQHT groups were treated with dexamethasone and SQHT by gavage, respectively. After treatment, superoxide dismutase (SOD) serum levels, total antioxidant capacity (TAOC), lipid peroxidation, and malondialdehyde (MDA) were detected by enzyme‐linked immunosorbent assay (ELISA). Activated protein kinase alpha (AMPK‐α), forkhead transcription factor O3a (FOXO3a), manganese SOD (MnSOD), and peroxisome proliferator‐activated receptor gamma (PPARγ) were detected using reverse transcriptase quantitative polymerase chain reaction (RT‐qPCR) and Western blot. Microribonucleic acid and protein expression levels were measured, and pathological changes in lung tissue were observed using hematoxylin and eosin staining. Results. The pathological findings suggested that SQHT substantially affects COPD treatment by enhancing alveolar fusion and reducing emphysema. ELISA results showed that SQHT could lower the blood levels of MDA and lipid peroxide and raise SOD and TAOC levels, suggesting that it could lessen oxidative stress. In the lung tissue of rats with COPD, large doses of SQHT intervention dramatically increased AMPK protein expression, AMPK‐α, FOXO3a, MnSOD, and PPARγ, indicating that SQHT may reduce oxidative stress by activating the PPARγ‐mediated AMPK/FOXO3a signaling pathway. Similar results were obtained using RT‐qPCR. Conclusion. SQHT is effective for COPD treatment. The mechanism of action may be related to the activation of the PPARγ‐mediated AMPK/FOXO3a signaling pathway to improve oxidative stress in lung tissue.

Bisdemethoxycurcumin alleviates LPS-induced acute lung injury via activating AMPKα pathway

ObjectiveInflammation and oxidative stress contribute to the pathogenesis of acute lung injury (ALI), and subsequently result in rapid deterioration in health. Considering the indispensable role of bisdemethoxycurcumin (BDMC) in inflammation and oxidative stress, the present study aims to examine the effect of BDMC on sepsis-related ALI.MethodsC57BL/6 mice were administered with BDMC (100 mg/kg) or an equal volume of vehicle, and then injected with lipopolysaccharides (LPS) to induce ALI. We assessed the parameters of lung injury, inflammatory response and oxidative stress in lung tissues. Consistently, the macrophages with or without BDMC treatment were exposed to LPS to verify the effect of BDMC in vitro.ResultsBDMC suppressed LPS-induced lung injury, inflammation and oxidative stress in vivo and in vitro. Mechanistically, BDMC increased the phosphorylation of AMPKα in response to LPS stimulation, and AMPK inhibition with Compound C almost completely blunted the protective effect of BDMC in LPS-treated mice and macrophages. Moreover, we demonstrated that BDMC activated AMPKα via the cAMP/Epac pathway.ConclusionOur study identifies the protective effect of BDMC against LPS-induced ALI, and the underlying mechanism may be related to the activation of cAMP/Epac/AMPKα signaling pathway.

Paroxetine protects against bleomycin-induced pulmonary fibrosis by blocking GRK2/Smad3 pathway.

G protein-coupled receptor kinase-2 (GRK2) is involved in TGF-β1-induced activation of lung fibroblasts, which could give rise to the pathogenesis of pulmonary fibrosis. Paroxetine (PRXT) serves as a selective GRK2 inhibitor which is widely used to treat anxiety and depression for several decades. However, whether PRXT could inhibit TGF-β1-induced activation of lung fibroblasts and combat bleomycin-induced pulmonary fibrosis remains unclear. Here, we investigated the effects of PRXT on pulmonary fibrosis in C57/BL6 caused by bleomycin as well as on the activation of murine primary lung fibroblasts stimulated with TGF-β1. The results demonstrated that PRXT markedly improved the pulmonary function and 21-day survival in bleomycin-induced mice. Meanwhile, PRXT significantly decreased collagen deposition, inflammation, and oxidative stress in lung tissues from bleomycin-induced mice. Furthermore, we found that PRXT could inhibit the protein and mRNA expression of GRK2 and Smad3 in lung tissues from bleomycin-induced mice. In vitro experiments also PRXT could inhibit cell activation and collagen synthesis in a concentration-dependent manner in TGF-β1-induced lung fibroblasts. In addition, we found that Smad3 overexpression by adenovirus transfection could offset anti-fibrotic and antioxidative effects from PRXT in TGF-β1-induced lung fibroblasts, which showed no effects on the protein expression of GRK2. In conclusion, PRXT mediates the inhibition of GRK2, which further blocks the transcription of Smad3 in TGF-β1-induced lung fibroblasts, providing an attractive therapeutic target for pulmonary fibrosis.

Plumbagin alleviates obesity-related asthma: Targeting inflammation, oxidative stress, and the AMPK pathway.

Obesity-related asthma, a specific type of asthma, tends to have more severe symptoms and more frequent exacerbations, and it is insensitive to standard medications. Plumbagin (PLB) has many positive effects on human health. However, it remains unclear whether PLB protects against obesity-related asthma. The study investigated the effect of PLB on obesity-related asthma. Four-week-old male C57BL6/J mice were fed either standard-chow diet or high-fat diet (HFD). The mice were sensitized to 100 μg ovalbumin (OVA) once a week and intraperitoneally injected with 1 mg/kg PLB once daily from Week 10 to 11 and then challenged with 10 μg OVA twice a day on Week 12. The lung tissue and bronchoalveolar lavage fluid (BALF) were collected 48 h after the first OVA challenge. HFD enhanced inflammatory cell infiltration within the airways and increased total inflammatory cell and eosinophil counts, levels of eosinophil-related inflammatory cytokines, including interleukin-4 (IL-4), IL-5, and eotaxin in BALF, and oxidative stress in the lung tissues of asthmatic mice. PLB reduced inflammatory cell infiltration in the airway walls, levels of eosinophil-related inflammatory cytokines in BALF, and oxidative stress in lung tissues of obese asthmatic mice. In addition, PLB restored HFD-induced decreases in adenosine monophosphate-activated protein kinase (AMPK) phosphorylation. The study suggested that HFD exacerbated inflammation and oxidative stress, while PLB probably alleviated inflammation and oxidative stress and activated AMPK pathway to attenuate obesity-associated asthma. Thus, PLB likely had the potential to treat obesity-related asthma.

Limonin, a novel AMPK activator, protects against LPS-induced acute lung injury

AMP-activated protein kinase (AMPK) activation plays crucial roles in the treatment of many oxidative stress- and inflammation-induced diseases, including acute lung injury (ALI). Limonin is a naturally occurring tetracyclic triterpenoid extracted from the plants of Rutaceae and Meliaceae. Limonin also serves as an AMPK activator with anti-inflammatory and anti-oxidation effects. However, the potential beneficial effects of limonin on ALI and the possible mechanisms have never been disclosed till now. Here, the effects of limonin on lipopolysaccharide (LPS)-induced ALI in C57 BL/6 mice, plus bone marrow-derived macrophages (BMDM) stimulated with LPS to induce in vitro ALI model were investigated. Limonin significantly improved pulmonary function and alleviated lung pathological injury in LPS-induced mice. Meanwhile, limonin also markedly decreased inflammation and oxidative stress in lung tissues from LPS-treated mice. In vitro experiments also unveiled that limonin could decrease inflammation and oxidative stress in LPS-induced BMDM in a concentration-dependent manner. Mechanically, limonin could promote the activation of AMPKα and upregulate the expression of nuclear factor erythroid 2-related factor 2 (NRF2) in lung tissues and BMDM. Pharmacological inhibition of AMPKα by Compound C or AMPKα knockout could abolish the pulmonary protection from limonin during ALI. In conclusion, limonin mediates the activation of AMPKα/NRF2 pathway, providing an attractive therapeutic target for ALI in the future.

The efficacy of caffeic acid phenethyl ester (CAPE) in the protection against radiation-induced oxidative stress in the lung as a distant organ

ObjectiveThe objective of this study is to measure the parameters of oxidative stress in the lungs of rats exposed to cranial radiation and to assess the potential radioprotective effectiveness of Caffeic acid phenethyl ester (CAPE). MethodsIn this study, 32 Sprague-Dawley rats were divided into four equal groups. The sham group received only non-radiation sham irradiation, the control group received dimethyl sulfoxide for ten days (1 ml/kg/day), the radiation group received a single dose of 5 Gy total cranial radiation and saline solution (1 ml/kg/day) for ten days, and the radiation plus CAPE group received a single dose of 5 Gy total cranial radiation and CAPE at a dose of 80 mg/kg/day, dissolved in 1 ml/kg/day of dimethyl sulfoxide for ten days. Oxidative and antioxidant parameters were measured in the lung tissue of rats. ResultsThe oxidative parameters, total oxidant status, oxidative stress index, and lipid hydroperoxide in the radiation group were significantly higher compared to the radiation plus CAPE group (p < 0.0001 for all). On the other hand, the antioxidative parameter, total antioxidant status, was significantly higher in the radiation plus CAPE group than in the other groups (p < 0.0001 for all). The levels of paraoxonase were also significantly higher in the radiation plus CAPE group compared to the other groups (p < 0.0001 for all). Ceruloplasmin was found to be higher in the control group than in the radiation group (p = 0.001). Additionally, arylesterase levels were significantly lower in the radiation group than in the other groups (p = 0.014, p = 0.002, p = 0.011). Thiol levels were lower in the radiation group compared to the sham and radiation plus CAPE groups (p = 0.013 and p = 0.004, respectively). ConclusionsThis study suggests that cranial radiation induces oxidative stress in lung tissue, and CAPE provides protection against oxidative damage by reducing oxidant parameters and increasing antioxidant parameters. These findings highlight the potential radioprotective effects of CAPE and its potential use as a therapeutic agent for mitigating the harmful effects of radiation-induced oxidative stress.

Glutamine inhibits inflammation, oxidative stress, and apoptosis and ameliorates hyperoxic lung injury.

Glutamine (Gln) is the most widely acting and abundant amino acid in the body and has anti-inflammatory properties, regulates body metabolism, and improves immune function. However, the mechanism of Gln's effect on hyperoxic lung injury in neonatal rats is unclear. Therefore, this work focused on examining Gln's function in lung injury of newborn rats mediated by hyperoxia and the underlying mechanism. We examined body mass and ratio of wet-to-dry lung tissue weights of neonatal rats. Hematoxylin and eosin (HE) staining was performed to examine histopathological alterations of lung tissues. In addition, enzyme-linked immunoassay (ELISA) was conducted to measure pro-inflammatory cytokine levels within bronchoalveolar lavage fluid (BALF). Apoptosis of lung tissues was observed using TUNEL assay. Western blotting was performed for detecting endoplasmic reticulum stress (ERS)-associated protein levels. The results showed that Gln promoted body weight gain, significantly reduced pathological damage and oxidative stress in lung tissue, and improved lung function in neonatal rats. Gln reduced pro-inflammatory cytokine release as well as inflammatory cell production in BALF and inhibited apoptosis in lung tissue cells. Furthermore, we found that Gln could downregulate ERS-associated protein levels (GRP78, Caspase-12, CHOP) and inhibit c-Jun N-terminal kinase (JNK) and inositol-requiring enzyme 1 alpha (IRE1α) phosphorylation. These results in an animal model of bronchopulmonary dysplasia (BPD) suggest that Gln may have a therapeutic effect on BPD by reducing lung inflammation, oxidative stress, and apoptosis and improving lung function; its mechanism of action may be related to the inhibition of the IRE1α/JNK pathway.

Soy isoflavone reduces LPS-induced acute lung injury via increasing aquaporin 1 and aquaporin 5 in rats.

Acute lung injury (ALI) followed with severe inflammation and oxidative stress. Anti-inflammatory and antioxidant are the properties of aquaporin 1 (AQP1) and aquaporin 5 (AQP5). The goal of this study was to see if soy isoflavone can diminish lipopolysaccharide (LPS)-induced ALI and the underling mechanism. LPS-induced ALI was given to Sprague-Dawley rats 14 days following oophorectomy. One hour before the LPS challenge, estradiol (1 mg/kg) was administered subcutaneously as positive control and soy isoflavone was intragastric administration for 14 days prior to LPS challenge with different doses. Six hours after LPS challenge, the pulmonary edema, pathophysiology, inflammation, and the oxidative stress in lung tissues of rats were discovered. We found that soy isoflavone can reduce pulmonary edema and the lung pathology in a dose-dependent manner. Furthermore, tumor necrosis factor-alpha, interleukin-1β, and interleukin-6 were decreased in rats treated with soy isoflavone. Meanwhile, soy isoflavone reduced pulmonary oxidative stress by decreasing malondialdehyde levels, while increasing superoxide dismutase levels in lung tissues in a dose-dependent manner. Mechanically, we found that the mRNA and protein level of AQP1 and AOP5 were increased in lung tissues of rats treated with soy isoflavone compared the LPS-treated rats. Thus, soy isoflavone alleviates LPS-induced ALI through inducing AQP1 and AQP5.

ROS-sensitive Crocin-loaded chitosan microspheres for lung targeting and attenuation of radiation-induced lung injury

Radiation-induced lung injury (RILI) is one of the major complications in patients exposed to accidental radiation and radiotherapy for thoracic malignancies. However, there is no reliable radioprotector for effective clinical treatment of RILI so far. Herein, a novel Crocin-loaded chitosan microsphere is developed for lung targeting and attenuation of RILI. The chitosan microspheres are modified with 4-carboxyphenylboronic acid and loaded with the natural antioxidant Crocin-I to give the drug-loaded microspheres (~10 μm). The microspheres possess good biocompatibility in vivo and in vitro. In a mouse model, they exhibit effective passive targeting performance and a long retention time in the lung after intravenous administration. Furthermore, they improve the radioprotective effect of Crocin-I for the treatment of RILI by reducing the level of inflammatory cytokines in bronchoalveolar lavage fluid and by regulating oxidative stress in lung tissues. The targeted agents significantly improved the bioavailability and radioprotection of Crocin-I by the outstanding passive targeting effect. This work may provide a promising strategy for efficient radioprotection on RILI using passive lung targeting microspheres.

Nrf2 regulates the expression of NOX1 in TNF-α-induced A549 cells

Acute lung injury causes severe inflammation and oxidative stress in lung tissues. In this study, we analyzed the potential regulatory role of nuclear factor erythroid-2-related factor 2 (Nrf2) on NADPH oxidase 1 (NOX1) in tumor necrosis factor-α (TNF-α)-induced inflammation and oxidative stress in human type II alveolar epithelial cells. In this study, A549 cells were transfected with Nrf2 siRNA and overexpression vectors for 6 h before being induced by TNF-α for 24 h. TNF-α upregulated the expression of NOX1 and Nrf2 in A549 cells. Furthermore, overexpression of Nrf2 could reduce TNF-α-induced NF-κB mRNA and protein expression after transfection with the Nrf2 siRNA vector, and the levels of IL-6, IL-8, ROS, and malondialdehyde (MDA) in TNF-α-induced A549 cells increased, while the level of total antioxidation capability (T-AOC) decreased. On the other hand, the overexpression of Nrf2 decreased the levels of IL-6, IL-8, ROS, and MDA, while increasing T-AOC. The mRNA and protein levels of NOX1 were dramatically increased by TNF-α, while those changes were notably suppressed by Nrf2 overexpression. Further studies demonstrated that Nrf2 suppressed NOX1 transcription by binding to the -1199 to -1189 bp (ATTACACAGCA) region of the NOX1 promoter in TNF-α-stimulated A549 cells. Our study suggests that Nrf2 may bind to and regulate NOX1 expression to antagonize TNF-α-induced inflammatory reaction and oxidative stress in A549 cells.

Attenuation of the Severity of Acute Respiratory Distress Syndrome by Pomiferin through Blocking Inflammation and Oxidative Stress in an AKT/Foxo1 Pathway-Dependent Manner.

Acute respiratory distress syndrome (ARDS) gives rise to uncontrolled inflammatory response and oxidative stress, causing very high mortality globally. Pomiferin is a kind of prenylated isoflavonoid extracted from Maclura pomifera, owning anti-inflammatory and antioxidant properties. However, the functions and possible mechanisms of pomiferin in lipopolysaccharide- (LPS-) induced ARDS remain unknown. C57BL/6 mice were injected with LPS (5 mg/kg) intratracheally to induce an in vivo ARDS model while RAW264.7 macrophages were stimulated with LPS (100 ng/ml) to induce an in vitro model. Our data demonstrated that pomiferin (20 mg/kg) significantly improved pulmonary function and lung pathological injury in mice with ARDS, apart from increasing survival rate. Meanwhile, pomiferin treatment also inhibited LPS-induced inflammation as well as oxidative stress in lung tissues. LPS stimulation significantly activated AKT/Foxo1 signal pathway in lung tissues, which could be reversed after pomiferin treatment. In vitro experiments further showed that 10, 20, and 50 μM of pomiferin could enhance cell viability of RAW264.7 macrophages stimulated with LPS. What is more, 3-deoxysappanchalcone (3-DE), one AKT agonist, was used to active AKT in RAW264.7 macrophages. The results further showed that 3-DE could abolish pomiferin-elicited protection in LPS-treated RAW264.7 macrophages, evidenced by activated inflammation and oxidative stress. Taken together, our study showed that pomiferin could exert an ARDS-protective effect by blocking the AKT/Foxo1 signal pathway to inhibit LPS-induced inflammatory response and oxidative injury, which may serve as a potential candidate for the treatment of ARDS in the future.

Effects of Corilagin on Lipopolysaccharide-Induced Acute Lung Injury via Regulation of NADPH Oxidase 2 and ERK/NF-κB Signaling Pathways in a Mouse Model.

Simple SummaryCorilagin has anti-inflammatory and antioxidant properties. Acute lung injury is a life-threatening disease. This investigated the protective effects and mechanisms of corilagin on acute lung injury. The results show that corilagin can reduce acute lung injury via attenuation of pro-inflammatory mediators and oxidative stress. Corilagin has potential utility as a therapeutic agent for the treatment of this life-threatening respiratory disease.Acute lung injury (ALI) and acute respiratory distress syndrome are clinically life-threatening diseases. Corilagin, a major polyphenolic compound obtained from the herb Phyllanthus urinaria, has anti-inflammatory and antioxidant properties, and in this study, we sought to evaluate the protective effects and mechanisms of corilagin on lipopolysaccharide (LPS)-induced ALI in mice. ALI was induced in the mice by the intratracheal administration of LPS, and following 30 min of LPS challenge, corilagin (5 and 10 mg/kg body weight) was administered intraperitoneally. At 6 h post-LPS administration, lung tissues were collected for analysis. Corilagin treatment significantly attenuated inflammatory cell infiltration, the production of pro-inflammatory cytokines TNF-α, IL-6, and IL-1β, and oxidative stress in lung tissues. In addition, corilagin inhibited the LPS-induced expression of NOX2, ERK, and NF-κB. Corilagin has anti-oxidative and anti-inflammatory effects, and can effectively reduce ALI via attenuation of the NOX2 and ERK/NF-κB signaling pathways.

Naringenin Improves Ovalbumin-Induced Allergic Asthma in Rats through Antioxidant and Anti-Inflammatory Effects

Asthma is a chronic disease with eosinophilic inflammation and oxidative damages leading to airway obstruction. Naringenin is a phytochemical possessing strong antioxidant and anti-inflammatory activities against chronic destructive conditions. The current study is devoted to evaluating naringenin's effects on the attenuation of inflammation and oxidative stress in lung tissue in a rat model of ovalbumin-induced asthma. Male Wistar rats were allocated to five groups of six: normal control (NC, receiving 1 ml/day of normal saline, orally), asthmatic (AS, receiving ovalbumin (1 mg/mL), and alum (1 mg/mL in saline) on days 0 and 14. Then, on days 21, 22, and 23, they were sensitized with the inhalation of ovalbumin), AS treated with dexamethasone (AS, 1 mg/kg/day, orally) [AS + D1], AS treated with naringenin (20 mg/kg/day, orally) [AS + N20], and AS treated with naringenin (40 mg/kg/day, orally) [AS + N40]. All the groups received associated drugs/agents for 28 days. Finally, bronchoalveolar lavage fluid (BALF) and lung tissue samples were taken off from the animals. The eosinophil count in BALF and malondialdehyde (MDA), glutathione (GSH), interleukin-13 and -4 (IL-13 and IL-4) levels were measured. Besides, the expression of urocortin (UCN) and surfactant protein-D (SP-D) were evaluated in the lung tissue using immunohistochemistry (IHC) and western blotting methods, respectively. Hematoxylin and eosin (H&E) staining were utilized to conduct histopathological analysis. Naringenin treatment significantly reduced MDA, remarkably increased GSH, and meaningfully reduced IL-4 and IL-13 levels in lung tissue. The count of eosinophils in the BALF of AS + N20 and AS + N40 was significantly reduced in comparison with the AS group. The UCN and SP-D protein levels were significantly decreased in the AS + N20 and AS + N40 groups compared to the AS group, using the IHC and western blot methods, respectively. Histopathological analysis data also confirm the results. Naringenin improves the symptoms of allergic asthma through antioxidant and anti-inflammatory effects.

MicroRNA-363-3p/sphingosine-1-phosphate receptor 1 axis inhibits sepsis-induced acute lung injury via the inactivation of nuclear factor kappa-B ligand signaling.

Infection-associated inflammation and coagulation are critical pathologies in sepsis-induced acute lung injury (ALI). This study aimed to investigate the effects of microRNA-363-3p (miR-363-3p) on sepsis-induced ALI and explore the underlying mechanisms. A cecal ligation and puncture-induced septic mouse model was established. The results of this study suggested that miR-363-3p was highly expressed in lung tissues of septic mice. Knockdown of miR-363-3p attenuated sepsis-induced histopathological damage, the inflammation response and oxidative stress in lung tissues. Furthermore, knockdown of miR-363-3p reduced the formation of platelet-derived microparticles and thrombin generation in blood samples of septic mice. Downregulation of miR-363-3p suppressed sphingosine-1-phosphate receptor 1 (S1PR1) expression in lung tissues and subsequently inactivated the nuclear factor kappa-B ligand (NF-κB) signaling. A luciferase reporter assay confirmed that miR-363-3p directly targeted the 3’-untranslated region of the mouse S1pr1 mRNA. Collectively, our study suggests that inactivation of NF-κB signaling is involved in the miR-363-3p/S1PR1 axis-mediated protective effect on septic ALI.