Chan-Mi Jeon

Melatonin attenuates neutrophil inflammation and mucus secretion in cigarette smoke-induced chronic obstructive pulmonary diseases via the suppression of Erk-Sp1 signaling.

The incidence of chronic obstructive pulmonary disease (COPD) has substantially increased in recent decade. Cigarette smoke (CS) is the most important risk factor in the development of COPD. In this study, we investigated the effects of melatonin on the development of COPD using a CS and lipopolysaccharide (LPS)‐induced COPD model and cigarette smoke condensate (CSC)‐stimulated NCI‐H292 cells, a human mucoepidermoid carcinoma cell. On day 4, the mice were treated intranasally with LPS. The mice were exposed to CS for 1 hr per day (8 cigarettes per day) from day 1 to day 7. Melatonin (10 or 20 mg/kg) was injected intraperitoneally 1 hr before CS exposure. Melatonin markedly decreased the neutrophil count in the BALF, with reduction in the proinflammatory mediators and MUC5AC. Melatonin inhibited Erk phosphorylation and Sp1 expression induced by CS and LPS treatment. Additionally, melatonin decreased airway inflammation with a reduction in myeloperoxidase expression in lung tissue. In in vitro experiments, melatonin suppressed the elevated expression of proinflammatory mediators induced by CSC treatment. Melatonin reduced Erk phosphorylation and Sp1 expression in CSC‐stimulated H292 cells. In addition, cotreatment of melatonin and Erk inhibitors significantly limited the proinflammatory mediators with greater reductions in Erk phosphorylation and Sp1 expression than that observed in H292 cells treated with Erk inhibitor alone. Taken together, melatonin effectively inhibited the neutrophil airway inflammation induced by CS and LPS treatment, which was closely related to downregulation of Erk phosphorylation. These findings suggest that melatonin has a therapeutic potential for the treatment of COPD.

Diallyl-disulfide, an organosulfur compound of garlic, attenuates airway inflammation via activation of the Nrf-2/HO-1 pathway and NF-kappaB suppression

Diallyl disulfide (DADS) is a major organosulfur compound found in garlic oil that is widely used as a flavoring agent. In this study, we evaluated the effects of DADS on airway inflammation using an ovalbumin-induced model of allergic asthma and RAW264.7 cells. DADS decreased nitric oxide production with a reduction in the levels of interleukins (IL)-1β and IL-6 in RAW264.7 cells stimulated with LPS. DADS also reduced the expression of proinflammatory proteins including inducible nitric oxide synthase (iNOS), nuclear factor (NF)-κB, and matrix metalloproteinase (MMP)-9, and it enhanced the expression of antioxidant proteins including Nrf-2 and hemeoxygenase (HO)-1. In in vivo experiments, DADS decreased the inflammatory cell count in the bronchoalveolar lavage fluid (BALF) with IL-4, IL-5, IL-13, and immunoglobulin (Ig) E. These results were consistent with the histological analysis. DADS attenuated the airway inflammation and mucus hypersecretion induced by OVA challenge. In addition, DADS induced the activation of Nrf-2 and the expression of HO-1. In contrast, DADS reduced the activation of NF-κB, iNOS and MMP-9. In conclusion, DADS reduced the airway inflammation via regulation of Nrf-2/HO-1 and NF-κB. These results suggest that DADS might represent a useful new oral therapy to treat allergic asthma.

Melatonin inhibits MUC5AC production via suppression of MAPK signaling in human airway epithelial cells

Mucus acts as a primary defense system in the airway against various stimuli. However, excess mucus production causes a reduction in lung function via limitation of the airflow in the airway of patients suffering from asthma or chronic obstructive pulmonary disease (COPD). In this study, we evaluated the effects of melatonin on the production of MUC5AC, a major constituent of the mucin that is secreted from the airway, using epidermal growth factor (EGF)‐stimulated NCI‐H292 cells, a human mucoepidermoid carcinoma cell line, and an ovalbumin (OVA)‐induced asthma murine model. Melatonin treatment significantly reduced the mRNA and protein levels of MUC5AC and reduced interleukin (IL)‐6 production in EGF‐stimulated H292 cells. Melatonin markedly decreased the phosphorylation of MAPKs, including ERK1/2, JNK, and p‐38, induced by EGF stimulation. These findings were consistent with the results using MAPK inhibitors. Particularly, co‐treatment with melatonin and a MAPK inhibitor more effectively suppressed MAPK phosphorylation than treatment with a MAPK inhibitor alone, which resulted in a reduction in MUC5AC expression. In the asthma murine model, melatonin‐treated mice exhibited a marked reduction in MUC5AC expression in the airway compared with the OVA‐induced mice. These reductions were accompanied by reductions in proinflammatory cytokine production and inflammatory cell infiltration. Collectively, these findings indicate that melatonin effectively inhibits MUC5AC expression. These effects may be closely associated with the inhibition of MAPK phosphorylation. Furthermore, our study suggests that melatonin could represent a potential therapeutic for chronic airway diseases, such as asthma and COPD.

Copper oxide nanoparticles aggravate airway inflammation and mucus production in asthmatic mice via MAPK signaling.

Abstract Copper oxide nanoparticles (CuONPs), metal oxide nanoparticles were used in multiple applications including wood preservation, antimicrobial textiles, catalysts for carbon monoxide oxidation and heat transfer fluid in machines. We investigated the effects of CuONPs on the respiratory system in Balb/c mice. In addition, to investigate the effects of CuONPs on asthma development, we used a murine model of ovalbumin (OVA)-induced asthma. CuONPs markedly increased airway hyper-responsiveness (AHR), inflammatory cell counts, proinflammatory cytokines and reactive oxygen species (ROS). CuONPs induced airway inflammation and mucus secretion with increases in phosphorylation of the MAPKs (Erk, JNK and p38). In the OVA-induced asthma model, CuONPs aggravated the increased AHR, inflammatory cell count, proinflammatory cytokines, ROS and immunoglobulin E induced by OVA exposure. In addition, CuONPs markedly increased inflammatory cell infiltration into the lung and mucus secretions, and MAPK phosphorylation was elevated compared to OVA-induced asthmatic mice. Taken together, CuONPs exhibited toxicity on the respiratory system, which was associated with the MAPK phosphorylation. In addition, CuONPs exposure aggravated the development of asthma. We conclude that CuONPs exposure has a potential toxicity in humans with respiratory disease.

Melatonin reduces airway inflammation in ovalbumin-induced asthma

Asthma is a common chronic inflammatory airway disease that is recognized as a major public health problem. In this study, we evaluated the effects of melatonin on allergic asthma using a murine model of ovalbumin (OVA)-induced allergic asthma and BEAS-2B cells. To induce allergic asthma, the mice were sensitized and airway-challenged with OVA. Melatonin was administered by intraperitoneal injection once per day at doses of 10 and 15 mg/kg from days 21 to 23 after the initial OVA sensitization. We investigated the effects of melatonin on proinflammatory cytokines and matrix metalloproteinase-9 (MMP-9) activity and expression in tumor necrosis factor (TNF)-α-stimulated BEAS-2B cells. The administration of melatonin significantly decreased the number of inflammatory cells, airway hyperresponsiveness, and immunoglobulin (Ig) E with reductions in interleukin (IL)-4, IL-5, and IL-13. Melatonin attenuated the airway inflammation and the mucus production in lung tissue and significantly suppressed elevated MMP-9 expression and activity induced by an OVA challenge. In TNF-α-stimulated BEAS-2B cells, treatment with melatonin significantly reduced the levels of proinflammatory cytokines and lowered the expression and activity of MMP-9. These results indicate that melatonin effectively suppressed allergic asthma induced by an OVA challenge. The results suggest a potential role for melatonin in treating asthma.

Inhibitory effects of Pycnogenol® (French maritime pine bark extract) on airway inflammation in ovalbumin-induced allergic asthma.

Pycnogenol® (PYC) is a standardized extracts from the bark of the French maritime pine (Pinus maritime) and used as a herbal remedy for various diseases. In this study, we evaluated the effects of PYC on airway inflammation using a model of ovalbumin (OVA)-induced allergic asthma and RAW264.7 cells. PYC decreased nitric oxide production and reduced the interleukine (IL)-1β and IL-6 levels in LPS-stimulated RAW264.7 cells. PYC also reduced the expression of inducible nitric oxide synthase (iNOS) and matrix metalloproteinase (MMP)-9 and enhanced the expression of hemeoxygenase (HO)-1. In the in vivo experiment, PYC decreased the inflammatory cell count and the levels of IL-4, IL-5, IL-13, and immunoglobulin (Ig) E in BALF or serum. These results are consistent with the histological analysis findings, which showed that PYC attenuated the airway inflammation and mucus hypersecretion induced by OVA challenge. In addition, PYC enhanced the expression of HO-1. In contrast, PYC inhibited the elevated expression of iNOS and MMP-9 proteins induced by OVA challenge. In conclusion, PYC exhibits protective effects against OVA-induced asthma and LPS-stimulated RAW264.7 cells. These results suggest that PYC has potential as a therapeutic agent for the treatment of allergic asthma.

EC-18, a synthetic monoacetyldiglyceride (1-palmitoyl-2-linoleoyl-3-acetylglycerol), attenuates the asthmatic response in an aluminum hydroxide/ovalbumin-induced model of asthma

EC-18 is a synthetic monoacetyldiaglyceride that is a major constituent in antlers of Sika deer (Cervus nippon Temmenick). In this study, we evaluated the protective effects of EC-18 on Th2-type cytokines, eosinophil infiltration, and other factors in an aluminum hydroxide/ovalbumin (OVA)-induced murine asthma model. Mice were sensitized on days 0 and 14 by intraperitoneal injection of OVA with aluminum hydroxide. On days 21, 22 and 23 after the initial sensitization, the mice received an airway challenge with OVA for 1h using an ultrasonic nebulizer. EC-18 was administered to mice by oral gavage at doses of 30mg/kg and 60mg/kg once daily from day 18 to 23. Methacholine responsiveness was measured 24h after the final OVA challenge, and the bronchoalveolar lavage fluid (BALF) was collected 48h after the final OVA challenge. EC-18 significantly reduced methacholine responsiveness, T helper type 2 (Th2) cytokines, eotaxin-1, immunoglobulin (Ig) E, IgG, and the number of inflammatory cells. In addition, EC-18-treated mice exhibited the reduction in the expression of inducible nitric oxide synthase (iNOS) in lung tissue. In the histological analysis using hematoxylin-eosin stain and periodic acid-Schiff stain, EC-18 attenuated the infiltration of inflammatory cells into the airway and reduced the level of mucus production. Our results showed that EC-18 effectively suppressed the asthmatic response induced by OVA challenge. These effects were considered to be associated with iNOS suppression. In conclusion, this study suggests that EC-18 may be a therapeutic agent for allergic asthma.

Callicarpa japonica Thunb. reduces inflammatory responses: a mouse model of lipopolysaccharide-induced acute lung injury.

Callicarpa japonica Thunb. (CJT) is traditionally used as an herbal remedy for the treatment of inflammatory diseases. This study aimed to investigate the anti-inflammatory response of CJT in lipopolysaccharide (LPS)-stimulated RAW264.7 cells and LPS-induced acute lung injury (ALI) in mice. The C57BL/6 mice were administered 30 mg/kg of CJT by oral gavage for 3 days. LPS is applied to animals by intranasal administration 1 h after final CJT treatment. LPS is applied to animals by intranasal administration 1h after final CJT treatment. LPS was delivered intranasally 1h after the final CJT treatment. In the LPS-stimulated RAW264.7 cells, CJT significantly decreased nitric oxide (NO) and interleukin (IL)-6 in a concentration-dependent manner by reducing inducible NO synthase (iNOS) and IL-6 mRNA levels. In the ALI model, CJT decreased the inflammatory cell count in the bronchoalveolar lavage fluid (BALF) while IL-6 levels were reduced in CJT-treated mice compared with the ALI control mice. CJT also inhibited airway inflammation by reducing iNOS expression in lung tissue. In conclusion, our results indicate that CJT inhibits inflammatory responses in LPS-stimulated RAW264.7 cells and in the LPS-induced ALI model. Therefore, we suggest that CJT has the potential to treat inflammatory diseases such as pneumonia.

Anti-inflammatory effects of methanol extract of Canarium lyi C.D. Dai & Yakovlev in RAW 264.7 macrophages and a murine model of lipopolysaccharide-induced lung injury

Canarium lyi C.D. Dai & Yakovlev (CL) is a member of the Anacardiaceae family. To the best of our knowledge, no studies on its anti-inflammatory effects have yet been reported. In the present study, we investigated the protective effects of CL on inflammation in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells and LPS-induced acute lung injury (ALI) mice. CL attenuated the production of LPS-stimulated inflammatory mediators such as tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, and interleukin-6 (IL-6). Furthermore, CL suppressed phosphorylation of the inhibitor κB-α (IκB-α), p38, c-Jun terminal kinase (JNK) and extracellular signal-regulated kinase (ERK), as well as the translocation of the nuclear factor-κB (NF-κB) p65 subunit into the nucleus. For the in vivo efficacy, the effect of CL on a mouse model of LPS-induced acute lung injury was assessed. CL treatment of the mice significantly inhibited the inflammatory cell recruitment and pro-inflammatory cytokine production in bronchoalveolar lavage fluids (BALF). CL-treated mice also showed a marked inhibition of cyclooxygenase-2 (COX-2) and phosphorylation of IκB and p65. In addition, CL attenuated lung histopathological changes in LPS-induced ALI mice. In conclusion, our results suggest that CL is a potential therapeutic candidate for the treatment of inflammatory diseases, including pneumonia.

Clausena anisata-mediated protection against lipopolysaccharide-induced acute lung injury in mice

Clausena anisata (Willd.) Hook.f. ex Benth. (CA), which is widely used in traditional medicine, reportedly exerts antitumor, anti-inflammatory and other important therapeutic effects. The aim of the present study was to investigate the potential therapeutic effects of CA in a mouse model of lipopolysaccharide (LPS)-induced acute lung injury (ALI) and in LPS-stimulated RAW 264.7 cells. Male C57BL/6 mice were administered treatments for 3 days by oral gavage. On day 3, the mice were instilled intranasally with LPS or PBS followed 3 h later by oral CA (30 mg/kg) or vehicle administration. In vitro, CA decreased nitric oxide (NO) production and pro-inflammatory cytokines, such as interleukin (IL)-6 and prostaglandin E2 (PGE2), in LPS-stimulated RAW 264.7 cells. CA also reduced the expression of pro-inflammatory mediators, such as cyclooxygenase-2. In vivo, CA administration significantly reduced inflammatory cell numbers in the bronchoalveolar lavage fluid (BALF) and suppressed pro-inflammatory cytokine levels, including tumor necrosis factor-α (TNF-α), IL-6, and IL-1β, as well as reactive oxygen species production in the BALF. CA also effectively reduced airway inflammation in mouse lung tissue of an LPS-induced ALI mouse model, in addition to decreasing inhibitor κB (IκB) and nuclear factor-κB (NF-κB) p65 phosphorylation. Taken together, the findings demonstrated that CA inhibited inflammatory responses in a mouse model of LPS-induced ALI and in LPS-stimulated RAW 264.7 cells. Thus, CA is a potential candidate for development as an adjunctive treatment for inflammatory disorders, such as ALI.