Na Chen

Jilin University, Jilin, Jilin Sheng, China

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Publications (21)41.55 Total impact

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    ABSTRACT: We investigated whether p-synephrine exerts potent anti-inflammatory effects against acute lung injury (ALI) induced by lipopolysaccharide (LPS) in vivo, and we further investigated the inhibitory mechanism of p-synephrine in LPS-induced ALI. Lipopolysaccharide (0.5 mg/kg) was instilled intranasally in phosphate-buffered saline to induce acute lung injury, and 6, 24, and 48 h after LPS was given, bronchoalveolar lavage fluid was obtained to measure pro-inflammatory mediator. We also evaluated the effects of p-synephrine on LPS-induced the severity of pulmonary injury. The phosphorylation of nuclear factor-κB (NF-κB) p65 protein was analyzed by Western blotting. Our data showed that p-synephrine significantly reduced the amount of inflammatory cells, the lung wet-to-dry weight (W/D) ratio, reactive oxygen species, myeloperoxidase activity and enhanced superoxide dismutase (SOD) in mice with LPS-induced ALI. Tumor necrosis factor α and interleukin (IL)-6 concentrations decreased significantly while the concentration of IL-10 was significantly increased after p-synephrine pretreatment. In addition, p-synephrine suppressed not only the phosphorylation of NF-κB but also the degradation of its inhibitor (IκBα). These results suggested that the inhibition of NF-κB activation and the regulation of SOD are involved in the mechanism of p-synephrine's protection against ALI.
    Agents and Actions 02/2014; · 1.59 Impact Factor
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    ABSTRACT: Bornyl acetate is a bicyclic monoterpene present in numerous conifer oils. In this study, we aimed at clarifying the potential anti-inflammatory function and mechanism of bornyl acetate by using lipopolysaccharide (LPS)-induced acute lung injury murine model and RAW 264.7 cells. RAW 264.7 cells were pretreated with bornyl acetate 1 h before LPS stimulation and cell-free super supernatants were collected to measure cytokine concentrations. To induce acute lung injury, BALB/c mice were injected intranasally with LPS and treated with bornyl acetate 1 h before LPS stimulation. Seven hours after administration, the bronchoalveolar lavage fluid (BALF) was collected for measuring the cell count and cytokine production. We collected lungs for assaying wet-to-dry weight ratio, myeloperoxidase activity, and histologic changes. The extent of phosphorylation of mitogen-activated protein kinases and nuclear factor κB was detected by Western blot. Our results showed that bornyl acetate downregulated the levels of proinflammatory cytokines in vitro and in vivo; reduced the number of total cells, neutrophils, and macrophages in BALF; attenuated the histologic alterations in the lung; decreased the wet-to-dry weight ratio in BALF; and suppressed NF-kappa-B inhibitor alpha, extracellular regulated protein kinases, c-JunN-terminal kinase, p38 mitogen-activated protein kinase activation. These findings suggested that bornyl acetate may be developed as a preventive agent for lung inflammatory diseases.
    Journal of Surgical Research 09/2013; · 2.02 Impact Factor
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    ABSTRACT: Abstract Context: Acute lung injury (ALI), characterized by severe hypoxemia, pulmonary edema and neutrophil accumulation in the lung, is a common clinical problem associated with significant morbidity and mortality in shock, sepsis, ischemia reperfusion, etc. Objective: In this study, we aimed at investigating the protective effect of tubeimoside-1 (TBMS1) on inflammation in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells and a LPS-induced in vivo lung injury model. Materials and methods: We evaluated the effect of TBMS1 on LPS-induced production of tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-1β in the culture supernatants of RAW 264.7 cells by enzyme-linked immunosorbent assay. LPS (0.5 mg/kg) was instilled intranasally in phosphate-buffered saline to induce ALI, and the severity of pulmonary injury was evaluated 6 h after LPS challenge. Results: TBMS1 significantly inhibited the production of the pro-inflammatory cytokines, TNF-α, IL-6 and IL-1β in vitro and in vivo. Pretreatment with TBMS1 markedly attenuated the development of pulmonary edema, histological severities and inflammatory cells infiltration in mice with ALI. In addition, we further demonstrated that TBMS1 exerts an anti-inflammatory effect in vivo model of ALI through suppression of IκB activation and p38/extracellular signal-regulated kinase mitogen-activated protein kinases signaling in a dose-dependent manner. Discussion and conclusion: Overall, our data suggest that TBMS1 inhibits inflammation both in vitro and in vivo, and may be a potential therapeutic candidate for the prevention of inflammatory diseases.
    Immunopharmacology and Immunotoxicology 07/2013; · 1.36 Impact Factor
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    ABSTRACT: Abstract Natural products have been used as potentially important sources of anti-inflammatory drugs. This study examined the effects of pinocembrin against lipopolysaccharide (LPS)-induced endotoxemia to ascertain whether pinocembrin could protect mice from ensuing death. Cytokine responses were also assessed in serum isolated from blood collected at 0, 2, 4, 6, 8, and 24 h after LPS administration of the mice (with or without drug treatment). The results showed that there was a lower production of TNFα, IL-6, and IL-1β in the serum of LPS-challenged mice that had been pre-treated with pinocembrin. In addition, pre-treatment with pinocembrin improved host survival against the LPS-induced lethal endotoxemia. These results suggest that this new flavonoid could potentially be a novel candidate for preventing development/mitigation progression of septic shock.
    Journal of Immunotoxicology 05/2013; · 1.57 Impact Factor
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    International Immunopharmacology. 05/2013; 16(1):122.
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    ABSTRACT: Prime-O-glucosylcimifugin is an active chromone isolated from Saposhnikovia root which has been reported to have various activities, such as anti-convulsant, anticancer, anti-inflammatory properties. The purpose of this study was to evaluate the effect of prime-O-glucosylcimifugin on acute lung injury (ALI) induced by lipopolysaccharide in mice. BALB/c mice received intraperitoneal injection of Prime-O-glucosylcimifugin 1h before intranasal instillation (i.n.) of lipopolysaccharide (LPS). Concentrations of tumor necrosis factor (TNF)-α, interleukin (IL)-1β and interleukin (IL)-6 in bronchoalveolar lavage fluid (BALF) were measured by enzyme-linked immunosorbent assay (ELISA). Pulmonary histological changes were evaluated by hematoxylin-eosin, myeloperoxidase (MPO) activity in the lung tissue and lung wet/dry weight ratios were observed. Furthermore, the mitogen-activated protein kinases (MAPK) signaling pathway activation and the phosphorylation of IκBα protein were determined by Western blot analysis. Prime-O-glucosylcimifugin showed promising anti-inflammatory effect by inhibiting the activation of MAPK and NF-κB signaling pathway.
    International immunopharmacology 04/2013; · 2.21 Impact Factor
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    ABSTRACT: AIMS: Natural products have been used as potentially important sources of novel antibacterials in combating pathogenic Staphylococcus aureus isolates, a major problem around the world. In the present study, we aimed to investigate the antibacterial effects of pinocembrin (PNCB) against S. aureus pneumonia in a murine model, and its influence on the production of S. aureus α-hemolysin (Hla). METHODS AND RESULTS: The in vitro activities of PNCB on α-hemolysin production were determined using hemolysis, western blot, and real-time RT-PCR assays. The viability and cytotoxicity assays were performed to evaluate the influence of PNCB on α-toxin-mediated injury of human alveolar epithelial cells. Moreover, through histopathologic analysis, we further determined the in vivo effects of PNCB on S. aureus pneumonia in a mouse model. In vitro, PNCB at low concentrations exhibited inhibitory activity against α-hemolysin production and attenuated α-haemolysin-mediated cell injury. Furthermore, the in vivo findings demonstrated that PNCB protected mice from S. aureus pneumonia. CONCLUSIONS: We have provided new evidence of the effects of pinocembrin, which suggest that PNCB attenuated α-haemolysin-mediated cell injury and protected mice from S. aureus pneumonia. SIGNIFICANCE AND IMPACT OF THE STUDY: The findings indicate that pinocembrin may be used as a basis for anti-Staphylococcus agent. This article is protected by copyright. All rights reserved.
    Journal of Applied Microbiology 04/2013; · 2.20 Impact Factor
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    Inflammation 03/2013; · 2.46 Impact Factor
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    ABSTRACT: Paeonol (2'-hydroxy-4'-methoxyacetophenone) is the main phenolic compound of the radix of Paeonia suffruticosa which has been used as traditional Chinese medicine. In this study, we primarily investigated the anti-inflammatory effects and the underlying mechanisms of paeonol in RAW macrophage cells; and based on these effects, we assessed the protective effects of paeonol on lipopolysaccharide-induced endotoxemia in mice. The in vitro study showed that paeonol regulated the production of TNF-α, IL-1β, IL-6, and IL-10 via inactivation of IκBα, ERK1/2, JNK, and p38 MAPK. In mouse model of lipopolysaccharide-induced endotoxemia, pro- and anti-inflammatory cytokines are significantly regulated, and thus the survival rates of lipolysaccharide-challenged mice are improved by paeonol (150, 200, or 250 mg/kg). Therefore, paeonol has a beneficial activity against lipopolysaccharide-induced inflammation in RAW 264.7 cell and mouse models.
    Fundamental and Clinical Pharmacology 02/2013; · 1.99 Impact Factor
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    ABSTRACT: The present study was designed to investigate the effects of p-cymene on lipopolysaccharide (LPS)-induced inflammatory cytokine production both in vitro and in vivo. The production of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), and interleukin-10 (IL-10) in LPS-stimulated RAW 264.7 cells and C57BL/6 mice was evaluated by sandwich ELISA. Meanwhile, the mRNA levels of cytokine genes were examined in vitro by semiquantitative RT-PCR. In a further study, we analyzed the activation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways by western blotting. We found that p-cymene significantly regulated TNF-α, IL-1β, and IL-6 production in LPS-stimulated RAW 264.7 cells. Furthermore, the levels of relative mRNAs were also found to be downregulated. In in vivo trail, p-cymene markedly suppressed the production of TNF-α and IL-1β and increased IL-10 secretion. We also found that p-cymene inhibited LPS-induced activation of extracellular signal receptor-activated kinase 1/2, p38, c-Jun N-terminal kinase, and IκBα. These results suggest that p-cymene may have a potential anti-inflammatory action on cytokine production by blocking NF-κB and MAPK signaling pathways.
    Inflammation 12/2012; · 2.46 Impact Factor
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    ABSTRACT: Imperatorin is a type of coumarin compound with antibacterial and antiviral activities. In the present study, we examined the anti-inflammatory effects of imperatorin in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages by investigating its impact on the production and expression of cytokines and the major signal-transduction pathways. We found that imperatorin downregulated LPS-induced levels of TNF-α, IL-1β, and IL-6 in RAW 264.7 macrophages in a concentration-dependent manner, and it significantly inhibited expression of TNF-α and IL-6 (P < 0.05 or P < 0.01). The phosphorylation of mitogen-activated protein kinases and nuclear factor-kappaB (NF-κB) p65 protein were analyzed by western blotting. In RAW 264.7 macrophages treated with 1 mg/L of LPS, imperatorin significantly inhibited p38 and Jun N-terminal kinase phosphorylation protein expression. However, there was no significant change in p-ERK. Furthermore, imperatorin also inhibited NF-κB translocation into the nucleus through blockage of IκBα phosphorylation and degradation.
    Inflammation 08/2012; · 2.46 Impact Factor
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    ABSTRACT: Imperatorin, a linear furanocoumarin, has many pharmacological effects such as antibacterial, anti-inflammatory and antiviral effects. The purpose of this study was to investigate the effect of Imperatorin on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice. BALB/c mice were pretreated with Imperatorin 1h before LPS challenge. We found that the levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6) in the bronchoalveolar lavage fluid (BALF) were decreased significantly, and the level of interleukin-10 (IL-10) was up-regulated 8h after Imperatorin treatment. Pretreatment with Imperatorin (15 or 30mg/kg) decreased lung wet-to-dry weight (W/D) ratio, the number of inflammatory cells and myeloperoxidase (MPO) activities. Additionally, Imperatorin attenuated lung histopathological changes and significantly inhibited the phosphorylation of IκB, JNK, ERK and p38/MAPK. These findings demonstrate that Imperatorin protects against LPS-induced ALI in mice.
    International immunopharmacology 08/2012; 14(4):369-374. · 2.21 Impact Factor
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    ABSTRACT: Salidroside is a major component extracted from Rhodiola rosea. In this study, we investigated protective effects of salidroside on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice. In the mouse model, we found that pretreatment with a single 120 mg/kg dose of salidroside prior to the administration of intratracheal LPS induced a significant decrease in the W/D ratio and mouse myeloperoxidase activity of lung, reduction protein concentration, the number of total cells, neutrophils and macrophages in the bronchoalveolar lavage fluid. In addition, salidroside also inhibited the production of several inflammatory cytokines, including tumor necrosis factor-α, interleukin-6 (IL-6) and IL-1β, and the NF-κB DNA-binding activation after LPS challenge. These results indicated that salidroside possess a protective effect on LPS-induced ALI in mice.
    Immunopharmacology and Immunotoxicology 08/2012; 34(4):667-72. · 1.36 Impact Factor
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    ABSTRACT: Pinocembrin or 5, 7-dihydroxyflavanone is a flavanone, a type of flavonoid. In the present study, we first assessed the anti-inflammatory effects of pinocembrin in RAW macrophage cells; and based on these effects, we investigated the therapeutic effects of pinocembrin in murine model of endotoxin-induced acute lung injury. We found that in vitro pretreatment with pinocembrin remarkably regulated the production of TNF-α, IL-1β, IL-6 and IL-10 via inhibiting the phosphorylation of IκBα, ERK1/2, JNK and p38MAPK. In the mouse model of LPS-induced acute lung injury, pinocembrin (20 or 50 mg/kg, i.p.) attenuated the development of pulmonary edema, histological severities, as well as neutrophil, lymphocyte and macrophage infiltration, which were increased by LPS administration. Additionally, TNF-α, IL-1β and IL-6 concentrations decreased significantly while the concentration of IL-10 was significantly increased after pinocembrin pretreatment. Our results also showed that pinocembrin attenuated LPS-induced lung injury through suppression of IκBα, JNK and p38MAPK activation. These findings suggest that pinocembrin may represent a novel candidate for the modulation of inflammatory responses.
    International immunopharmacology 06/2012; 14(1):66-74. · 2.21 Impact Factor
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    ABSTRACT: Astragalin (AG), a flavonoid from many traditional herbs and medicinal plants, has been described to exhibit in vitro anti-inflammatory activity. The present study aimed to determine the protective effects and the underlying mechanisms of astragalin on lipopolysaccharide-induced endotoxemia and lung injury in mice. Mice were injected intraperitoneally (i.p.) with lipopolysaccharide (LPS) (dose range: 5-40 mg/kg). We observed mice on mortality for 7 days twice a day and recorded survival rates. In drug testing, we examined the therapeutic effects of astragalin (25, 50 or 75 mg/kg) on LPS- induced endotoxemia by dosing orally astragalin 1 hour before LPS challenge. Using an experimental model of LPS-induced acute lung injury (ALI), we examined the effect of astragalin in resolving lung injury. The investigations revealed that pretreatment with astragalin can improve survival during lethal endotoxemia and attenuate inflammatory responses in a murine model of lipopolysaccharide-induced acute lung injury. The mechanisms by which Astragalin exerts its anti-inflammatory effect are correlated with inhibition of tumor necrosis factor-α (TNF-α), interleukin-1 (IL-1), and interleukin-6 (IL-6) production via inactivation of NF-κB.
    Biochemical and Biophysical Research Communications 02/2012; 419(2):256-61. · 2.41 Impact Factor
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    ABSTRACT: 7-O-Methylnaringenin, extracted from Rhododendron speciferum, belongs to the flavanone class of polyphenols. In the present study, we investigated the anti-inflammatory effects of 7-O-methylnaringenin on cytokine production by lipopoly-saccharide (LPS)-stimulated RAW 264.7 macrophages in vitro. The results showed that pretreatment with 10, 20 or 40 μg/mL of 7-O-methylnaringenin could downregulate tumour necrosis factor (TNF-α), interleukin (IL-6) and interleukin (IL-1β) in a dose-dependent manner. Furthermore, we investigated the signal transduction mechanisms to determine how 7-O-methylnaringenin affects RAW 264.7 macrophages. The activation of mitogen-activated protein kinases (MAPK) and IκBα were measured by Western blotting. The data showed that 7-O-methylnaringenin could downregulate LPS-induced levels of phosphorylation of ERK1/2, JNK and IκBα. These observations indicated that 7-O-methylnaringenin modulated inflammatory cytokine responses by blocking NF-қB, ERK1/2 and JNK/MAPKs activation.
    Molecules 01/2012; 17(3):3574-85. · 2.43 Impact Factor
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    ABSTRACT: The objective of this study was to test the hypothesis that p-cymene can attenuate acute lung injury induced by lipopolysaccharide (LPS) in vivo. In the mouse model of LPS-induced acute lung injury, intraperitoneal preconditioning with p-cymene resulted in a significant reduction of pro-inflammatory cytokines (TNF-α, IL-1β and IL-6), lung water gain, inflammatory cell infiltration, lung tissue myeloperoxidase activity. In addition, p-cymene blocked the phosphorylation of IκBα protein and mitogen-activated protein kinases (MAPK) signaling pathway activation. Histopathologic examination of lung tissue indicated that p-cymene treatment markedly decreased focal thickening, congestion, pulmonary edema, and inflammatory cells infiltration. The results showed that p-cymene had a protective effect on LPS-induced ALI in mice.
    Molecules 01/2012; 17(7):8159-73. · 2.43 Impact Factor
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    ABSTRACT: Alpinetin, one of the main constituents of the seeds of Alpinia katsumadai Hayata, belonging to flavonoids, has been known to exhibit antibacterial, anti-inflammatory and other important therapeutic activities. The purpose of this study was to investigate the protection of alpinetin on inflammation in Lipopolysaccharide (LPS) stimulated Raw 264.7 cells and LPS induced vivo lung injury model. The effects of alpinetin on pro-inflammatory cytokines and signaling pathways were analyzed by enzyme-linked immunosorbent assay and Western blot. The results showed that alpinetin markedly inhibited the LPS- induced TNF-α, IL-6 and IL-1β production both in vitro and vivo. Furthermore, alpinetin blocked the phosphorylation of IκBα protein, p65, p38 and extracellular signal-regulated kinase (ERK) in LPS stimulated RAW 264.7 cells. From in vivo study, it was also observed that alpinetin attenuated lung histopathologic changes in mouse models. These results suggest that alpinetin potentially decreases the inflammation in vitro and vivo, and might be a therapeutic agent against inflammatory diseases.
    International Immunopharmacology 12/2011; 12(1):241-8. · 2.42 Impact Factor
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    ABSTRACT: Salidroside is a major component isolated from the Rhodiola rosea. In the present study, we investigated the anti-inflammatory effects of salidroside on cytokine production by lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages in vitro, and the results showed that salidroside reduced tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β) secretions. This inspired us to further study the effects of salidroside in vivo. Salidroside significantly attenuated TNF-α, IL-1β and IL-6 productions in serum from mice challenged with LPS, and consistent with the results in vitro. In the murine model of endotoxemia, mice were treated with salidroside prior to or after LPS challenge. The results showed that salidroside significantly increased mouse survival. Further studies revealed that salidroside could downregulate LPS-induced nuclear transcription factor-қB (NF-қB) DNA-binding activation and ERK/MAPKs signal transduction pathways production in RAW 264.7 macrophages. These observations indicated that salidroside modulated early cytokine responses by blocking NF-қB and ERK/MAPKs activation, and thus, increased mouse survival. These effects of salidroside may be of potential usefulness in the treatment of inflammation-mediated endotoxemia.
    International immunopharmacology 12/2011; 11(12):2194-9. · 2.21 Impact Factor
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    ABSTRACT: Asthma is an inflammatory disease of the lungs that is characterised by increased inflammatory cell infiltration into the airways and poor respiratory function. Ivermectin is a semi-synthetic derivative of a family of macrocyclic lactones that shows broad-spectrum anti-parasitic activity. This drug has been shown to possess anti-inflammatory activity, but whether it can be used in asthma treatment has not yet been investigated. In this study, we aimed to investigate the inhibitory effects of ivermectin on allergic asthma symptoms in mice. We used a mouse asthma model, in which allergic airway inflammation and airway remodelling were induced by ovalbumin (OVA) sensitisation and challenge. Ivermectin or PBS treatment was administered 1 h before OVA challenge. Ivermectin at 2 mg/kg significantly diminished recruitment of immune cells, production of cytokines in the bronchoalveolar lavage fluids and secretion of OVA-specific IgE and IgG1 in the serum. Histological studies indicated that ivermectin suppressed mucus hypersecretion by goblet cells in the airway. This is the first study to demonstrate that ivermectin is an effective suppressor of inflammation and may be efficacious in the treatment of non-infectious airway inflammatory diseases such as allergic asthma.
    Agents and Actions 01/2011; 60(6):589-96. · 1.59 Impact Factor