Intranasal Instillation Of Lipopolysaccharide Research Articles

Retinoids stored locally in the lung are required to attenuate the severity of acute lung injury in male mice

Retinoids are potent transcriptional regulators that act in regulating cell proliferation, differentiation, and other cellular processes. We carried out studies in male mice to establish the importance of local cellular retinoid stores within the lung alveolus for maintaining its health in the face of an acute inflammatory challenge induced by intranasal instillation of lipopolysaccharide. We also undertook single cell RNA sequencing and bioinformatic analyses to identify roles for different alveolar cell populations involved in mediating these retinoid-dependent responses. Here we show that local retinoid stores and uncompromised metabolism and signaling within the lung are required to lessen the severity of an acute inflammatory challenge. Unexpectedly, our data also establish that alveolar cells other than lipofibroblasts, specifically microvascular endothelial and alveolar epithelial cells, are able to take up lipoprotein-transported retinoid and to accumulate cellular retinoid stores that are directly used to respond to an acute inflammatory challenge.

Protective effect of Palmijihwanghwan in a mouse model of cigarette smoke and lipopolysaccharide-induced chronic obstructive pulmonary disease

BackgroundPalmijihwanghwan (PJH) is a traditional medicine and eight constituents derived from PJH possess anti-inflammatory activities. However, the scientific evidence for its potential as a therapeutic agent for inflammatory lung disease has not yet been studied. In this study, we examined the protective effect of PJH in a mouse model of chronic obstructive pulmonary disease (COPD) induced by cigarette smoke (CS) with lipopolysaccharide (LPS).MethodsMice received CS exposure for 8 weeks and intranasal instillation of LPS on weeks 1, 3, 5 and 7. PJH (100 and 200 mg/kg) was administrated daily 1 h before CS treatment for the last 4 weeks.ResultsCompared with CS plus LPS-exposed mice, mice in the PJH-treated group showed significantly decreased inflammatory cells count and reduced inflammatory cytokines including interleukin-1 beta (IL-1β), IL-6 and tumor necrosis factor alpha (TNF-α) levels in broncho-alveolar lavage fluid (BALF) and lung tissue. PJH also suppressed the phosphorylation of nuclear factor kappa B (NF-κB) and extracellular signal-regulated kinase1/2 (ERK1/2) caused by CS plus LPS exposure. Furthermore, CS plus LPS induced increases in matrix metallopeptidase (MMP)-7, MMP-9, and transforming growth factor-β (TGF-β) expression and collagen deposition that were inhibited in PJH-treated mice.ConclusionsThis study demonstrates that PJH prevents respiratory inflammation and airway remodeling caused by CS with LPS exposure suggesting potential therapy for the treatment of COPD.

Echinacoside attenuates lipopolysaccharide-induced acute lung injury in newborn mice via inactivation of NF- κB/NLRP3 signaling pathway

Purpose: To investigate the effect of echinacoside (ECH) on acute lung injury (ALI) and the underlying mechanism of action.Methods: The ALI model was established through intranasal instillation of lipopolysaccharide (LPS). Lung tissue damage was determined using hematoxylin and eosin (H&E) staining and lung wet-to-dry–weight ratio. Bronchoalveolar lavage fluid (BALF) protein concentration, cell count, and cytokine level were evaluated. Western blotting was used to determine protein expression level.Results: ECH attenuated lung tissue injury and lung wet-to-dry–weight ratio in the ALI model (p < 0.01). The total protein content and number of total cells, neutrophils, and macrophages increased in BALF of mice treated with LPS, but these increases were reversed by ECH treatment (p < 0.01). The levels of TNF-α and IL-1β increased in BALF and lung tissue of LPS-treated mice; however, ECH treatment decreased these changes (p < 0.01). In addition, ECH inhibited the activation of the nuclear factor-κB (NF-κB)/NLR family pyrin domain containing 3 (NLRP3) pathway in LPS-treated mice (p < 0.01).Conclusion: Echinacoside attenuates LPS-induced ALI via inactivation of the NF-κB/NLRP3 pathway, making echinacoside a potential drug for the treatment of ALI.
 Keywords: Echinacoside, Acute lung injury, Lipopolysaccharide, Nuclear factor-κB, NLR family pyrin domain containing 3

Anti-inflammatory and protective effects of D-carvone on lipopolysaccharide (LPS)-induced acute lung injury in mice

Lung inflammation is a common cause of health problem and death among adults and children. Antioxidant compounds have the capability to overcome this complication. This study targets to examine the anti-inflammatory and defensive role of D-carvone on lipopolysaccharide (LPS)-initiated lung damage in mice. Male BALB/c mice (n = 8) received intragastric feeding of D-carvone (25 and 50 mg/kg b.w.) or dexamethasone (5 mg/kg b.w.) an hour before intranasal instillation of LPS (20 µg). Seven hours after LPS instillation, the bronchoalveolar lavage fluid (BALF), blood serum, and tissue samples of lung were studied for the levels of inflammatory cells, antioxidant enzymes, pro-inflammatory cytokines, and histopathological changes. D-carvone significantly alleviated (p < 0.05) the lung damage caused by LPS by reducing the lung wet-to-dry (W/D) ratio along with the amount of total cells, macrophages, and neutrophils in BALF (p < 0.05). The serum TNF-α, IL-1β, and IL-6 were remarkably reduced (p < 0.05) in D-carvone treated mice. Histopathological derangements because of LPS-initiated lung damage were altered by D-carvone. The results of D-carvone were comparable with the positive control dexamethasone. Pre-treatment of D-carvone significantly provided anti-inflammatory and protective effect in LPS-instigated lung damage. Together, these findings acknowledge the use of D-carvone as preventive agent for lung damage and inflammation. Further research on the pharmacokinetics, pathway and mechanism of action of D-carvone are necessary to promote D-carvone as a commercial anti-inflammatory drug.

Effect of Intranasal Instillation of Lipopolysaccharide on Lung Development and Its Related Mechanism in Newborn Mice.

Premature infants are prone to repeated lung infections after birth, which can disrupt the development of lung structure and function. However, the effects of postnatal pulmonary inflammation on lung development in newborn mice have not been reported and may play an important role in the development of bronchopulmonary dysplasia (BPD). This study aimed to establish a BPD model of postnatal pulmonary inflammation in premature infants and to explore its role and possible mechanisms in the pathogenesis of BPD. We exposed postnatal day 1 mice to lipopolysaccharide (LPS) and normal saline for 14 days. Pulmonary inflammation and alveolar microvascular development were assessed by histology. In addition, we also examined the expression of vascular endothelial growth factor (VEGF), VEGFR2, nuclear factor-kappa-B (NF-κB) and related inflammatory mediators [interleukin-1β (IL-1β), tumor necrosis factor-alpha (TNF-α), macrophage inflammatory protein-1α (MIP-1α), monocyte chemoattractant protein-1 (MCP-1)] in the lungs. Lung histology revealed inflammatory cell infiltration, alveolar simplification, and decreased microvascular density in LPS-exposed lungs. VEGF and VEGFR2 expression was decreased in the lungs of LPS-exposed neonatal mice. Furthermore, we detected elevated levels of the inflammatory mediators IL-1β, TNF-α, MIP-1α, and MCP-1 in the lungs, which are associated with the activation of NF-κB. Intranasal instillation of LPS inhibits lung development in newborn mice, and postnatal pulmonary inflammation may participate in the pathogenesis of BPD. The mechanism is related to the inhibition of VEGF and VEGFR2 and the upregulation of inflammatory mediators through activation of NF-κB.

Protective Effects of Isoliquiritigenin on LPS-Induced Acute Lung Injury by Activating PPAR-γ.

Isoliquiritigenin (ILG), a major ingredient of licorice, has been reported to have anti-oxidative and anti-inflammatory effects. The aim of this study was to investigate the protective effects of ILG on lung injury using an animal model of lipopolysaccharide (LPS)-induced acute lung injury (ALI). Male BALB/c mice were conditioned with ILG 1h before intranasal instillation of LPS. The effects of ILG on lung injury were assessed by measuring lung histopathological examination, MPO assay, wet/dry (W/D) ratio, and inflammatory cytokine production. The results showed that ILG significantly inhibited LPS-induced lung histopathological changes and the MPO activity. Meanwhile, it attenuated the wet/dry (W/D) ratio in the lung tissues. The results also indicated that ILG inhibited LPS-induced ALI in the expression of inflammatory cytokines in the BALF. Furthermore, ILG can decrease the activity of NF-κB and can increase the expression of PPAR-γ. These findings suggested that ILG inhibited the inflammatory of LPS-induced lung injury by activating PPAR-γ and inhibiting NF-κB activation.

Nobiletin-Ameliorated Lipopolysaccharide-Induced Inflammation in Acute Lung Injury by Suppression of NF-κB Pathway In Vivo and Vitro.

Nobiletin (NOB), a citrus polymethoxy flavonoid, has been reported to exhibit anti-inflammatory, anti-cancer, and anti-insulin resistance activities. Although the anti-inflammatory activity of NOB already reported, its involvement in lung protection has not been reported. Thus, this study aimed to investigate the anti-inflammatory response of NOB in lipopolysaccharide (LPS)-stimulated A549 cells and LPS-induced acute lung injury (ALI) in mice. The animals were pre-treated with NOB (5, 10, and 20mg/kg) or DEX (5mg/kg) at 12 and 1h before intranasal instillation of LPS. The severity of pulmonary injury was evaluated 6h after LPS administration. Results suggested that treatment with NOB dramatically attenuated lung histopathological changes, wet-to-dry (W/D) ratio, myeloperoxidase (MPO) activity, the numbers of inflammatory cells, and TNF-α, IL-6, and NO in BALF induced by LPS. Furthermore, NOB also significantly inhibited the expression of iNOS and the phosphorylation of NF-κBp65 and IκBα. In vitro, NOB inhibited NF-κB activation and TNF-α, IL-6 production in LPS-stimulated A549 cells. Taken together, these results indicated that NOB exhibited a protective effect on ALI, and the possible mechanism is involved in inhibiting NF-κB activation, subsequently inhibiting LPS-induced inflammatory response.

4-Hydroxycinnamic acid protects mice from cigarette smoke-induced pulmonary inflammation via MAPK pathways

Cigarette smoke (CS) is the main etiological cause of chronic obstructive pulmonary disease, the prevalence of which has continuously increased in recent years. 4-Hydroxycinnamic acid (HA) is a plant phenolic acid that has anti-inflammatory activities. In this study, we explored the therapeutic effects of HA on airway inflammation caused by CS and lipopolysaccharide (LPS) in mice. The animals received 1 h of CS exposure for 7 days and intranasal instillation of LPS on day 4. HA (10 and 20 mg/kg) was administered to animals via oral gavage 1 h before CS exposure. HA treatment significantly decreased the accumulation of inflammatory cells and production of cytokines, including tumor necrosis factor-α, interleukin (IL)-6, and IL-1β, caused by CS and LPS exposure. After histological examination, we observed that HA treatment significantly reduced the infiltration of inflammatory cells into lung tissue caused by CS and LPS exposure. Furthermore, HA-treated groups showed significantly decreased phosphorylation of extracellular signal-regulated kinase, c-Jun N-terminal kinase, p38, and nuclear factor-κB, and activity of cytochrome c oxidase subunit-2 caused by CS and LPS. In conclusion, HA effectively suppresses the airway inflammatory response induced by CS and LPS exposure, and is closely associated with the downregulation of mitogen-activated protein kinases signaling.

Saikosaponin a Ameliorates LPS-Induced Acute Lung Injury in Mice.

The purpose of this study was to investigate the protective effects of Saikosaponin a (SSa), a triterpene saponin derived from Radix bupleuri, on lipopolysaccharide (LPS)-induced acute lung injury (ALI) using a murine model. The mice were given SSa 1h after intranasal instillation of LPS. Then, lung histopathological examination, the wet/dry (W/D) ratio, myeloperoxidase (MPO), and inflammatory cytokines in bronchoalveolar lavage fluid (BALF) were detected in this study. The results showed that SSa reduced lung pathological injury induced by LPS. Furthermore, LPS-induced lung W/D ratio, MPO activity, and inflammatory cytokines TNF-α and IL-1β in BALF were significantly inhibited by SSa. In addition, SSa suppressed LPS-induced NF-κB activation and NLRP3 inflammasome expression. In conclusion, we found that SSa played a critical anti-inflammatory effect through inhibition of NF-κB and NLRP3 signaling pathways and protected against LPS-induced ALI.

Therapeutic effects of silibinin on LPS-induced acute lung injury by inhibiting NLRP3 and NF-κB signaling pathways.

Silibinin, a natural product extracted from Silybum marianum (milk thistle), has been reported to have anti-inflammatory effect. The aim of this study was to explore the therapeutic effects and potential mechanisms of silibinin on lipopolysaccharide (LPS)-stimulated inflammatory responses in acute lung injury (ALI). Male BALB/c mice were conditioned with silibinin 1h after intranasal instillation of LPS. After 12h, the myeloperoxidase (MPO) level in lung tissues, the wet/dry (W/D) ratio, inflammatory cytokines in the bronchoalveolar lavage fluid (BALF), and histopathological examination of lung were detected. Our results showed that silibinin inhibited LPS-induced histopathological changes and MPO activity, as well as the wet/dry (W/D) ratio in the lung tissues. Furthermore, silibinin significantly inhibited LPS-induced inflammatory cytokines production in the BALF. In addition, silibinin suppressed LPS-induced NF-κB activation and the expression of NLRP3 inflammasome. These results indicate that silibinin exerts its anti-inflammatory effect by inhibiting NF-κB and NLRP3 signaling pathways.

Amphiregulin suppresses epithelial cell apoptosis in lipopolysaccharide-induced lung injury in mice

Background and objectiveAs a member of the epidermal growth factor family, amphiregulin contributes to the regulation of cell proliferation. Amphiregulin was reported to be upregulated in damaged lung tissues in patients with chronic obstructive pulmonary disease and asthma and in lung epithelial cells in a ventilator-associated lung injury model. In this study, we investigated the effect of amphiregulin on lipopolysaccharide (LPS)-induced acute lung injury in mice. MethodsAcute lung injury was induced by intranasal instillation of LPS in female C57BL/6 mice, and the mice were given intraperitoneal injections of recombinant amphiregulin or phosphate-buffered saline 6 and 0.5 h before and 3 h after LPS instillation. The effect of amphiregulin on apoptosis and apoptotic pathways in a murine lung alveolar type II epithelial cell line (LA-4 cells) were examined using flow cytometry and western blotting, respectively. ResultsRecombinant amphiregulin suppressed epithelial cell apoptosis in LPS-induced lung injury in mice. Western blotting revealed that amphiregulin suppressed epithelial cell apoptosis by inhibiting caspase-8 activity. ConclusionAmphiregulin signaling may be a therapeutic target for LPS-induced lung injury treatment through its prevention of epithelial cell apoptosis.

Salidroside Protects Lipopolysaccharide-Induced Acute Lung Injury in Mice.

Salidroside (SDS) has been reported to have anti-inflammatory properties. The objective of this study was to investigate the protective effect of SDS on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice. BALB/c mice were pretreated with SDS 1 hour before intranasal instillation of LPS. Seven hours after LPS administration, the myeloperoxidase in histology of lungs, lung wet/dry ratio, and inflammatory cells in the bronchoalveolar lavage fluid (BALF) were determined. The levels of pro-inflammatory cytokines, tumor necrosis factor α (TNF-α), interleukin-1β (IL 1β), and IL-6 in the BALF were measured by enzyme-linked immunosorbent assay. The expression of Toll-like receptor 4 (TLR4), inhibitor of nuclear factor-kappa B (IκB-α), and nuclear factor-kappa B (NF-κB) p65 was detected by Western blot. The SDS reduced the inflammatory cells in BALF, decreased the wet/dry ratio of lungs, attenuated the LPS-induced histological alterations in the lung, and inhibited the production of TNF-α, IL-1β, and IL-6. Western blot showed that SDS efficiently inhibited the phosphorylation of IκB-α, p65 NF-κB, and the expression of TLR4. These data show that the anti-inflammatory effects of SDS (at least 20 mg/kg) against LPS-induced ALI due to its ability to inhibit TLR4 mediated the NF-κB signaling pathways. The SDS may represent a novel strategy for treating LPS-induced ALI.

The Effect of Bone Marrow Mononuclear Cells on Lung Regeneration and Apoptosis in a Simple Model of Pulmonary Emphysema.

BackgroundIn severe chronic stages of emphysema the only treatment is lung transplantation. SO, an urgent need exists for the development of effective treatments. Stem cells therapy arises as a new therapeutic approach.Aim of the WorkTo investigate whether bone marrow mononuclar cells (BMMNCs) can promote lung regeneration and decrease apoptosis in lipopolysaccharide (LPS) induced pulmonary emphysema in C57Bl/6 mice.Material and Methods14 weeks old female mice (C57Bl/6), weighing around 25 g were used in this study. The mice were divided into 4 groups (10 in each group): group A: mice received no treatment, group B: mice received intranasal instillation of LPS with no further treatment, group C: mice received intranasal instillation of LPS then given a dose of BMMNCs and evaluated 21 days later and group D: the mice that received intranasal instillation of LPS then given a dose of Dulbecco’s Modified Eagle’s Medium (DMEM) and evaluated 21 days later. Imaging analysis was done using imagej program. To measure apoptotic index, Anti–caspase 3 polyclonal antibody staining was done.ResultsAnalysis of the mean of airspace equivalent diameters (D0) and its statistical distribution (D1) for the different groups allowed to observe that group treated with BMMNCs (group C) showed the significant improvement in D0 and D1 than the group received LPS only (group B). Analysis of apoptotic index showed significant difference between BMMNCs treated group (group C) and that received LPS only (group B).ConclusionsBMMNCs effectively promote lung regeneration and reduction of apoptosis in pulmonary emphysema.

Trapa japonica Pericarp Extract Reduces LPS-Induced Inflammation in Macrophages and Acute Lung Injury in Mice.

In this study, we found that chloroform fraction (CF) from TJP ethanolic extract inhibited lipopolysaccharide (LPS)-induced production of nitric oxide (NO) and intracellular ROS in RAW264.7 cells. In addition, expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) genes was reduced, as evidenced by western blot. Our results indicate that CF exerts anti-inflammatory effects by down-regulating expression of iNOS and COX-2 genes through inhibition of MAPK (ERK, JNK and p38) and NF-κB signaling. Similarly we also evaluated the effects of CF on LPS-induced acute lung injury. Male Balb/c mice were pretreated with dexamethasone or CF 1 h before intranasal instillation of LPS. Eight hours after LPS administration, the inflammatory cells in the bronchoalveolar lavage fluid (BALF) were determined. The results indicated that CF inhibited LPS-induced TNF-α and IL-6 production in a dose dependent manner. It was also observed that CF attenuated LPS-induced lung histopathologic changes. In conclusion, these data demonstrate that the protective effect of CF on LPS-induced acute lung injury (ALI) in mice might relate to the suppression of excessive inflammatory responses in lung tissue. Thus, it can be suggested that CF might be a potential therapeutic agent for ALI.

Epidermal growth factor receptor inhibitor AG1478 inhibits mucus hypersecretion in airway epithelium.

Mucus hypersecretion and neutrophil infiltration are important characteristics of airway inflammation. Epidermal growth factor receptor (EGFR) transactivation induces mucus and inflammatory cytokine secretion from airway epithelial cells. To elucidate the roles of EGFR in airway inflammation, the in vitro effects on mucin production and interleukin (IL) 8 secretion from cultured airway epithelial cells and the in vivo effects on mucus hypersecretion and neutrophil infiltration in rat nasal mucosa of the EGFR tyrosine kinase inhibitor AG1478 were examined. The in vitro effects of AG1478 treatment of cultured NCI-H292 cells on lipopolysaccharide (LPS) induced or tumor necrosis factor (TNF) α induced MUC5AC mucin and IL-8 secretion were evaluated. Hypertrophic and metaplastic changes of goblet cells, mucus production and neutrophil infiltration in rat nasal epithelium were induced by intranasal instillation of LPS in vivo, and the inhibitory effects of AG1478 by intraperitoneal injection or intranasal instillation were examined. AG1478 (1-1000 nM) significantly inhibited both LPS-induced and TNF-α-induced secretion of MUC5AC and IL-8 from cultured NCI-H292 cells in a dose-dependent manner. The expression of MUC5AC and IL-8 messenger RNAs was also significantly inhibited. Intranasal instillation of AG1478 one hour after intranasal LPS instillation significantly inhibited LPS-induced goblet cell metaplasia, mucus production, and neutrophil infiltration in rat nasal epithelium, as did intraperitoneal injection of AG1478 one hour before LPS instillation. These results indicated that EGFR transactivation plays an important role in mucin and IL-8 secretion from airway epithelial cells. Intranasal instillation of an EGFR tyrosine kinase inhibitor may be a new therapeutic approach for the treatment of upper airway inflammation.

In vitro and in vivo anti-inflammatory effects of the chloroform fraction from Trapa japonica pericarp

In this study, we found that the chloroform fraction (CF) from Trapa japonica pericarp (TJP) ethanolic extract inhibited lipopolysaccharide (LPS)-induced production of nitric oxide (NO) and intracellular ROS in RAW264.7 cells. In addition, expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) genes were reduced, as evidenced by Western blots. Our results indicate that CF exerts anti-inflammatory effects by down-regulating expression of iNOS and COX-2 genes through inhibition of MAPK (ERK, JNK and p38) and NF-κB signaling. Similarly, we also evaluated the effects of CF on LPS-induced acute lung injury. Male Balb/c mice were pretreated with dexamethasone or CF 1 hr before intranasal instillation of LPS. Eight hours after LPS administration, the inflammatory cells in the bronchoalveolar lavage fluid (BALF) were determined. The results indicated that CF inhibited LPS-induced TNF-α and IL-6 production in a dose dependent manner. It was also observed that CF attenuated LPS-induced lung histopathologic changes. In conclusion, these data demonstrate that the protective effect of CF on LPS-induced acute lung injury (ALI) in mice might relate to the suppression of excessive inflammatory responses in lung tissue. Thus, it can be suggested that CF might be a potential therapeutic agent for ALI.

Effects of chrysin on steroid-resistant asthma in a murine model

To explore the therapeutic effects of chrysin for steroid-resistant asthma in a murine model. Lipopolysaccharide (LPS) was used to induce steroid-resistant asthma in a murine model sensitized and challenged with ovalbumin (OVA). Forty-eight female BALB/c mice were randomly divided into 6 groups of control (A), OVA (B), LPS + OVA (C), LPS + OVA + dexamethasone (D), LPS + OVA + chrysin (E) and LPS + OVA + dexamethasone + chrysin (F) (n = 8 each). At Day 1 and 14, group A received an intraperitoneal injection of phosphate buffered saline (PBS); groups B, C, D, E and F had an intraperitoneal injection of a mixture of OVA (20 µg) and aluminum hydroxide for sensitization. At Day 27, groups A and B were intranasally instilled with PBS while groups C, D, E and F had an intranasal instillation of LPS (10 µg). At Days 28, 29 and 30, groups B, C, D, E and F were challenged via airway with 1% OVA in PBS for 30 min and group A with PBS. Group D was intraperitoneally injected with dexamethasone (3 mg/kg) 30 min pre-challenge and PBS one day pre-challenge; group E received an intraperitoneal injection of chrysin (50 mg/kg) at one day and 1h pre-challenge; group F received dexamethasone (3 mg/kg) 30 min pre-challenge and chrysin (50 mg/kg) at one day and 1 h pre-challenge; groups A, B and C had PBS as above. Hematoxylin-eosin (HE) staining and periodic acid-Schiff (PAS) staining of lung tissues were performed to observe the pathologic changes. The total cells in bronchoalveolar lavage fluid (BALF) were counted under microscope. And enzyme-linked immunosorbent assay (ELISA) was applied for detecting interleukin-4 (IL-4) and interleukin-13 (IL-13) in BALF and IgE in sera. The inflammatory infiltration in lung tissue of group F was obviously suppressed compared with that of group C. The numbers of PAS-positive cells per bronchus divided by the total number of epithelial cells in group D, E, F were markedly lower than that in group C ((54.5 ± 6.9)%, (53.3 ± 8.2)%, (23.8 ± 7.0)% vs (71.3 ± 12.2)%, all P < 0.01). The total cells in BALF of group E and F significantly decreased versus that of group C ((1.22 ± 0.23) × 10⁴/ml, (0.98 ± 0.25) × 10⁴/ml vs (2.56 ± 0.18) × 10⁴/ml, both P < 0.01). The levels of IL-4 in group D and F were significantly less than that of group C ((118 ± 7), (124 ± 5) vs (138 ± 6) pg/ml, both P < 0.01). The levels of IL-13 in BALF of group E and F significantly decreased compared with that of group C ((787 ± 57), (484 ± 32) vs (1 121 ± 132) pg/ml, both P < 0.01). The levels of IgE in sera of group D, E, F were significantly lower those of group C ((10 310 ± 494), (10 771 ± 650), (7 529 ± 485) vs (12 618 ± 595) ng/ml, all P < 0.01). Chrysin could improve the therapeutic efficacies of glucocorticoid for steroid-resistant asthma.

Protective effect of Jolkinolide B on LPS-induced mouse acute lung injury.

Jolkinolide B (JB), an ent-abietane diterpenoid, isolated from the dried root of Euphorbia fischeriana, has been reported to have potent anti-tumor and anti-inflammatory activities. However, the effects of JB on acute lung injury (ALI) and underlying molecular mechanisms have not been investigated. The present study aimed to investigate the effect of JB on lipopolysaccharide (LPS)-induced ALI. Male C57BL/6 mice were pretreated with dexamethasone or JB 1h before intranasal instillation of LPS. The results showed that JB markedly attenuated LPS-induced histological alterations, lung edema, inflammatory cell infiltration, myeloperoxidase (MPO) activity as well as the production of TNF-α, IL-6 and IL-1β. Furthermore, JB also significantly inhibited LPS-induced the degradation of IκBα and phosphorylation of NF-κB p65 and MAPK. Therefore, our study provides the first line of evidence that pretreatment of JB has a protective effect on LPS-induced ALI in mice. The anti-inflammatory mechanism of JB may be attributed to its suppression of NF-κB and MAPK activation.

Protective effects of scoparone against lipopolysaccharide-induced acute lung injury.

The purpose of this study was to investigate the protective effects and molecular mechanisms of scoparone on lipopolysaccharide (LPS)-induced acute lung injury in mice. Mice model of acute lung injury (ALI), induced by intranasal instillation of LPS, was used to investigate the protective effects of scoparone in vivo. The alveolar macrophages were used to investigate the molecular mechanisms of scoparone in vitro. The results showed that scoparone treatment remarkably attenuated LPS-induced pulmonary edema, histological severities, myeloperoxidase activity, and TNF-α, IL-6 and IL-1β production in vivo. We also found that scoparone inhibited LPS-induced TLR4 expression, NF-κB activation, TNF-α, IL-6 and IL-1β production in alveolar macrophages in vitro. In conclusion, our results suggest that scoparone has a protective effect on LPS-induced ALI via suppression of TLR4-mediated NF-κB signaling pathways.

Protective effect of catalpol on lipopolysaccharide-induced acute lung injury in mice.

Catalpol, an iridiod glucoside isolated from Rehmannia glutinosa, has been reported to have anti-inflammatory properties. Although anti-inflammatory activity of catalpol already reported, its involvement in lung protection has not been reported. Thus, we investigated the role of catalpol on lipopolysaccharide (LPS)-induced acute lung injury in this study. Mice acute lung injury model was induced by intranasal instillation of LPS. Catalpol was administrated 1h prior to or after LPS exposure. The severity of pulmonary injury was evaluated 12h after LPS administration. The results showed that catalpol inhibited lung W/D ratio, myeloperoxidase activity of lung samples, the amounts of inflammatory cells and TNF-α, IL-6, IL-4 and IL-1β in BALF induced by LPS. The production of IL-10 in BALF was up-regulated by catalpol. In vitro, catalpol inhibited TNF-α, IL-6, IL-4 and IL-1β production and up-regulated IL-10 expression in LPS-stimulated alveolar macrophages. Moreover, western blot analysis showed that the activation of NF-κB and MAPK signaling pathways was inhibited by catalpol. Furthermore, catalpol was found to inhibit TLR4 expression induced by LPS. In conclusion, catalpol potently protected against LPS-induced ALI. The protective effect may attribute to the inhibition of TLR4-mediated NF-κB and MAPK signaling pathways.