Effects of budesonide and N-acetylcysteine on acute lung hyperinflation, inflammation and injury in rats

Poly(malic acid)-budesonide nanoconjugates embedded in microparticles for lung administration

To improve the therapeutic activity of inhaled glucocorticoids and reduce potential side effects, we designed a formulation combining the advantages of nanoparticles, which have an enhanced uptake by alveolar cells, allow targeted delivery and sustained drug release, as well as limited drug systemic passage, with those of microparticles, which display good alveolar deposition. Herein, a polymer-drug conjugate, poly(malic acid)-budesonide (PMAB), was first synthesized with either 11, 20, 33, or 43 mol% budesonide (drug:polymer from 1:8 to 3:4), the drug creating hydrophobic domains. The obtained conjugates self-assemble into nanoconjugates in water, yielding excellent drug loading of up to 73 wt%, with 80-100 nm diameters. In vitro assays showed that budesonide could be steadily released from the nanoconjugates, and the anti-inflammatory activity was preserved, as evidenced by reduced cytokine production in LPS-activated RAW 264.7 macrophages. Nanoconjugates were then embedded into microparticles through spray-drying with L-leucine, forming nano-embedded microparticles (NEMs). NEMs were produced with an aerodynamic diameter close to 1 µm and a density below 0.1 g.cm-3, indicative of a high alveolar deposition. NEMs spray-dried with the less hydrophobic nanoconjugates, PMAB 1:4, were readily dissolved in simulated lung fluid and were chosen for in vivo experiments to study pharmacokinetics in healthy rats. As it was released in vivo from NEMs, sustained distribution of budesonide was obtained for 48 h in lung tissue, cells, and lining fluid. With high loading rates, modulable release kinetics, and low cytotoxicity, these nanoconjugates delivered by NEMs are promising for the more efficient treatment of pulmonary inflammatory diseases.

Budesonide and N-acetylcysteine inhibit activation of the NLRP3 inflammasome by regulating miR-381 to alleviate acute lung injury caused by the pyroptosis-mediated inflammatory response

Background

The anti-inflammatory effects of budesonide (BUN) and N-acetylcysteine (NAC) attenuate acute lung injury (ALI). The aim of this study was to investigate the effects of combination therapy consisting of BUN and NAC on ALI and the underlying mechanisms.

Methods

In vitro and in vivo models of ALI were generated by LPS induction. Western blotting was used to detect the expression levels of pyroptosis-related proteins and inflammation-related factors, and RT-qPCR was used to detect the expression of miR-381. Cell proliferation and apoptosis were detected by CCK-8 and flow cytometry, respectively. ELISA was used to detect the levels of inflammation-related factors. HE staining was used to detect lung injury.

Results

The results showed that LPS effectively induced pyroptosis in cells and promoted the expression of pyroptosis-related proteins (Caspase1, Gasdermin D and NLRP3) and inflammatory cytokines (TNF-α, IL-6 and IL-1β). The combination of BUN and NAC significantly alleviated LPS-induced pyroptosis and inflammation. In addition, the combination of BUN and NAC effectively promoted miR-381 expression. Transfection of miR-381 mimics effectively alleviated LPS-induced pyroptosis and inflammation, while transfection of miR-381 inhibitors had the opposite effect. miR-381 negatively regulates NLRP3 expression. Treatment with a miR-381 inhibitor or pc-NLRP3 reversed the effects of the combination of BUN and NAC. In a mouse model of ALI, the combination of BUN and NAC effectively improved lung injury, while treatment with a miR-381 inhibitor or pc-NLRP3 effectively reversed this effect.

Conclusion

Overall, this study revealed that BUN + NAC inhibits the activation of NLRP3 by regulating miR-381, thereby alleviating ALI caused by pyroptosis-mediated inflammation.

Inhaled Corticosteroids Use Before Hospitalization May Be Protective in Children With Direct Lung Injury

BACKGROUND

Systemic corticosteroid use in acute respiratory failure has yielded uncertain benefits, partially because of off-target side effects. Inhaled corticosteroids (ICSs) confer localized antiinflammatory benefits and may protect adults with direct lung injury (DLI) from developing respiratory failure. To our knowledge, this relationship has not been studied in children.

RESEARCH QUESTION

Do children with DLI who are prescribed ICSs before hospitalization have lower odds of progressing to respiratory failure?

STUDY DESIGN AND METHODS

This retrospective, single-center cohort identified children seeking treatment at the ED with DLI and medication records before hospitalization. The primary outcome was intubation; secondary outcomes included noninvasive respiratory support (NRS). We tested the association of ICSs with intubation and NRS, adjusting for confounders. We stratified analyses on history of asthma and performed a sensitivity analysis adjusting for systemic corticosteroid use to account for status asthmaticus.

RESULTS

Of 35,220 patients, 17,649 patients (50%) were prescribed ICSs. Intubation occurred in 169 patients (73 patients receiving ICSs) and NRS was used in 3,582 patients (1,336 patients receiving ICS). ICS use was associated with lower intubation (adjusted OR, 0.46; 95% CI, 0.31-0.67) and NRS (aOR, 0.45; 95% CI, 0.40-0.49). The association between ICS and NRS differed according to history of asthma (P = .04 for interaction), with ICS exposure remaining protective only for patients with a history of asthma. Results held true in sensitivity analyses.

INTERPRETATION

ICS use prior to hospitalization may protect children with DLI from progressing to respiratory failure, with possible differential efficacy according to history of asthma.

Combination therapy with budesonide and acetylcysteine alleviates LPS-induced acute lung injury via the miR-381/NLRP3 molecular axis

BACKGROUND

Acute lung injury (ALI) usually has a high morbidity and mortality rate, but the current treatment is relatively scarce. Both budesonide (Bud) and N-acetylcysteine (NAC) exhibit protective effects in ALI, so we further investigated whether they have a synergistic effect on ALI when used together.

METHODS

Establishment of a rat model of ALI with Lipopolysaccharide (LPS). Bud and NAC were administered by nebulized inhalation alone or in combination. Subsequently, HE staining was performed to observe the pathological changes in lungs of rat. Evans blue staining was implemented to assess alveolar permeability, and the pulmonary edema was assessed by measuring the ratio of wet to dry weight of the lung. Moreover, a TUNEL kit was served to test apoptosis in lung tissues. Western blot and immunohistochemistry were analyzed for expression of scorch-related proteins and NLRP3 in lung tissue, respectively. ELISA was implemented to detect inflammatory factor levels in BALF. and RT-qPCR was utilized to assess the expression level of miR-381. After stable transfection of miR-381 inhibitor or OE-NLRP3 in BEAS-2B treated with LPS, Bud and NAC, miR-381 expression was assessed by RT-qPCR, scorch death-related protein expression was measured by western blot, cell proliferation/viability was assayed by CCK-8, apoptosis was measured by flow cytometry, and ELISA was implemented to assess inflammatory factor levels. Furthermore, the Dual-luciferase assay was used to verify the targeting relationship.

RESULTS

Bud and NAC treatment alone or in combination with nebulized inhalation attenuated the increased alveolar permeability, pulmonary edema, inflammatory response and scorching in LPS-induced ALI rats, and combined treatment with Bud and NAC was the most effective. In addition, combined treatment with Bud and NAC upregulated miR-381 expression and inhibited NLRP3 expression in cellular models and LPS-induced ALI rats. Transfection of the miR-381 inhibitor and OE-NLRP3 partially reversed the protective effects of Bud and NAC combination treatment on BEAS-2B cell proliferation inhibition, apoptosis, focal death and the inflammatory response.

CONCLUSION

Combined Bud and NAC nebulization therapy alleviates LPS-induced ALI by modulating the miR-381/NLRP3 molecular axis.

Inhaled ciclesonide in adults hospitalised with COVID-19: a randomised controlled open-label trial (HALT COVID-19)

OBJECTIVE

To assess the efficacy of inhaled ciclesonide in reducing the duration of oxygen therapy (an indicator of time to clinical improvement) among adults hospitalised with COVID-19.

DESIGN

Multicentre, randomised, controlled, open-label trial.

SETTING

9 hospitals (3 academic hospitals and 6 non-academic hospitals) in Sweden between 1 June 2020 and 17 May 2021.

PARTICIPANTS

Adults hospitalised with COVID-19 and receiving oxygen therapy.

INTERVENTION

Inhaled ciclesonide 320 µg two times a day for 14 days versus standard care.

MAIN OUTCOME MEASURES

Primary outcome was duration of oxygen therapy, an indicator of time to clinical improvement. Key secondary outcome was a composite of invasive mechanical ventilation/death.

RESULTS

Data from 98 participants were analysed (48 receiving ciclesonide and 50 receiving standard care; median (IQR) age, 59.5 (49-67) years; 67 (68%) men). Median (IQR) duration of oxygen therapy was 5.5 (3-9) days in the ciclesonide group and 4 (2-7) days in the standard care group (HR for termination of oxygen therapy 0.73 (95% CI 0.47 to 1.11), with the upper 95% CI being compatible with a 10% relative reduction in oxygen therapy duration, corresponding to a <1 day absolute reduction in a post-hoc calculation). Three participants in each group died/received invasive mechanical ventilation (HR 0.90 (95% CI 0.15 to 5.32)). The trial was discontinued early due to slow enrolment.

CONCLUSIONS

In patients hospitalised with COVID-19 receiving oxygen therapy, this trial ruled out, with 0.95 confidence, a treatment effect of ciclesonide corresponding to more than a 1 day reduction in duration of oxygen therapy. Ciclesonide is unlikely to improve this outcome meaningfully.

TRIAL REGISTRATION NUMBER

NCT04381364.

Bioactive fraction from Plumeria obtusa L. attenuates LPS-induced acute lung injury in mice and inflammation in RAW 264.7 macrophages: LC/QToF-MS and molecular docking

In this study, the anti-inflammatory effects of the methanolic extract (TE) of Plumeria obtusa L. (aerial parts) and its fractions were evaluated in vitro, and active fraction was evaluated in vivo. Among tested extracts, dichloromethane fraction (DCM-F) exhibited the strongest inhibition of lipopolysaccharide (LPS)-induced nitric oxide (NO) in RAW 264.7 macrophages. The effect of DCM-F on LPS-induced acute lung injury (ALI) in mice was studied. The animals were divided into five groups (n = 7) randomly; Gp I: negative control, GP II: positive control (LPS group), GP III: standard (dexamethasone, 2 mg/kg b.wt), GP IV and V: DCM-F (100 mg/kg), and DEM-F (200 mg/kg), respectively. DCM-F at a dose of 200 mg/kg suppressed the ability of LPS to increase the levels of nitric oxide synthase (iNOS), NO, tumor necrosis factor-α (TNF-α), and interleukin 6 (IL-6), as measured by ELISA. In addition, the expression of cyclooxygenase-2 (COX-2) was reduced (determined by immunohistochemistry) and the level of malondialdehyde (MDA) was decreased while that of catalase was restored to the normal values. Furthermore, the histopathological scores of inflammation induced by LPS were reduced. Twenty-two compounds were tentatively identified in DCM-F using LC/ESI-QToF with iridoids, phenolic derivatives and flavonoids as major constituents. Identified compounds were subjected to two different molecular docking processes against iNOS and prostaglandin E synthase-1 target receptors. Notably, protoplumericin A and 13-O-coumaroyl plumeride were the most promising members compared to the co-crystallized inhibitor in each case. These findings suggested that DCM-F attenuates the LPS-induced ALI in experimental animals through its anti-inflammatory and antioxidant potential.

Crosstalk between Inflammation and Hemorrhage/Coagulation Disorders in Primary Blast Lung Injury

Primary blast lung injury (PBLI), caused by exposure to high-intensity pressure waves from explosions in war, terrorist attacks, industrial production, and life explosions, is associated with pulmonary parenchymal tissue injury and severe ventilation insufficiency. PBLI patients, characterized by diffused intra-alveolar destruction, including hemorrhage and inflammation, might deteriorate into acute respiratory distress syndrome (ARDS) with high mortality. However, due to the absence of guidelines about PBLI, emergency doctors and rescue teams treating PBLI patients rely on experience. The goal of this review is to summarize the mechanisms of PBLI and their cross-linkages, exploring potential diagnostic and therapeutic targets of PBLI. We summarize the pathophysiological performance and pharmacotherapy principles of PBLI. In particular, we emphasize the crosstalk between hemorrhage and inflammation, as well as coagulation, and we propose early control of hemorrhage as the main treatment of PBLI. We also summarize several available therapy methods, including some novel internal hemostatic nanoparticles to prevent the vicious circle of inflammation and coagulation disorders. We hope that this review can provide information about the mechanisms, diagnosis, and treatment of PBLI for all interested investigators.

Combination therapy with budesonide and N-acetylcysteine ameliorates LPS-induced ALI by attenuating neutrophil recruitment through the miR-196b-5p/Socs3 molecular axis

Background

Neutrophil infiltration accelerates the inflammatory response and is highly correlated to the development of acute lung injury (ALI). Budesonide (BUD) and N-acetylcysteine (NAC) both inhibit the inflammatory response to alleviate ALI, so we further investigated whether their combination is better for ALI.

Methods

In this study, we investigated the effect and mechanism of Combined BUD and NAC therapy on LPS-induced ALI. Rat ALI model and neutrophil abnormal activation model were established by lipopolysaccharide (LPS). BUD and NAC were treated alone or in combination, or cells were transfected with miR-196b-5p mimic or si-Socs3 to evaluate the efficacy and mechanism of BUD and NAC alone or in combination. Histopathological observation of lungs was performed by Hematoxylin Eosin (HE) staining. The quantity of neutrophils and inflammatory factors level in bronchoalveolar lavage fluid (BALF) were determined by Richter-Gimza complex stain and Enzyme-Linked Immunosorbnent Assay (ELISA), respectively. ReverseTranscription-PolymeraseChainReaction (RT–qPCR) was utilized to assess miR-196b-5p and inflammatory factor mRNA levels. The expression level of Socs3 was detected by immunohistochemistry or Western Blot.

Results

BUD and NAC combined treatment had a better effect on neutrophil recruitment and inflammatory response in LPS-induced ALI than did BUD and NAC alone. Transfection of the miR-196b-5p mimic reversed the effect of combined BUD and NAC. In conclusion, the combination of BUD and NAC is a better treatment for ALI.

Conclusions

Combination therapy with BUD and NAC ameliorates LPS-induced ALI by attenuating neutrophil recruitment through the miR-196b-5p/Socs3 molecular axis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-02185-7.

Bioactive phenolics fraction of Hedera helix L. (Common Ivy Leaf) standardized extract ameliorates LPS-induced acute lung injury in the mouse model through the inhibition of proinflammatory cytokines and oxidative stress

Hedera helix L. (family Araliaceae) is classified as a conventional plant used as a medicinal product in the cure and prevention of upper respiratory tract inflammation and infection due to its secretolytic and broncholytic effects. Our research was conducted to authenticate the anti-inflammatory effect of ivy leaves extract in the prevention of acute lung injury (ALI) caused by intranasal administration of lipopolysaccharides (LPS). In-vitro antimicrobial, anti-inflammatory, and anti-oxidant were evaluated, in addition to the in-vivo acute lung inflammation model induced by LPS in mice. The animals were divided into seven groups randomly (each group containing 10 mice): control negative (saline only), control positive (LPS group), standard (Dexamethasone 2 mg/kg), ethanolic ivy leaves extract (EIE, 100 mg/kg), ethanolic ivy leaves extract (EIE, 200 mg/kg), saponin rich fraction (SRF, 100 mg/kg) and phenolic rich fraction (PRF, 100 mg/kg). Right lungs were homogenized to determine the levels of SOD, MDA, catalase, IL-10, TNF-α, NO, IL-1β, IL-6, PGE2, and MPO. Left lungs were excised for histopathology and histomorphometry. Immunohistochemistry of Cox-2 and TNF-α levels were measured. Additionally, Western blotting was used to determine the levels of phosphorylated MAPK. Also, the ethanolic extract was also standardized through HPLC analysis for its content of rutin.The data showed that the oral supplementation with EIE, 200 mg/kg significantly (P < 0.05) decreased the pro-inflammatory mediators, and oxidative stress biomarkers induced by LPS. Interestingly, the phenolics showed promising activity, therefore they are responsible for the action. In conclusion, the standardized ivy leaf extract could be advised for acute lung injury for its antimicrobial, anti-oxidant, and anti-inflammatory activities.

•

Ivy leaf is a traditional perennial edible herb used as an anti-inflammatory agent for respiratory disorders.

•

The plant significantly reduced the serum oxidative stress biomarkers and inflammatory cytokines in the in-vivo acute lung inflammation model induced by LPS.

•

Also, it had antimicrobial activity.

•

Phenolics not saponins are responsible for the activity of the plant.

Adjuvant Inhaled Corticosteroids in Community-Acquired Pneumonia: A Review Article

Community-acquired pneumonia is still a major cause of morbidity and mortality worldwide. Since the inflammatory response induced by the immune system is often a major contributor to the lung injury, it becomes reasonable to assess the potential benefit of anti-inflammatory agents in treating community-acquired pneumonia. The role of corticosteroids as adjunct anti-inflammatory agents in treating community-acquired pneumonia is still controversial. Several studies have assessed the benefit of their use in patients with community-acquired pneumonia. In most of those studies, the route of corticosteroids administration was systemic. The aim of this article is to provide a concise review of the role of corticosteroids in treating community-acquired pneumonia when administered via inhalational route, with the potential benefit of avoiding systemic side effects of corticosteroids while exerting the same anti-inflammatory effects on the lungs. Conclusion: the use of inhaled corticosteroids may be of benefit in certain patient subsets with community-acquired pneumonia. Further randomized controlled trials are needed for better determination of such patient subsets.

Modulation of bleomycin-induced oxidative stress and pulmonary fibrosis by N-acetylcysteine in rats via AMPK/SIRT1/NF-κβ

The efficacy of bleomycin (BLM) as an antineoplastic drug is limited to the development of dose and time-dependent pulmonary fibrosis. This study was intended to investigate the effect of N-acetylcysteine (NAC) on BLM-induced pulmonary fibrosis in rats. Twenty rats were randomly divided to the following four groups: Group one served as control; group two received BLM (15 mg/kg, intraperitoneal (ip)) for five consecutive days; group three received NAC (200 mg/kg, ip) for five consecutive days; and group four received NAC 1 hour before BLM for 5 days. The expression of connective tissue growth factor (CTGF), platelet-derived growth factor (PDGF), silent information regulator l (SIRT1), AMP-activated protein kinase (AMPK) were determined by qRT-PCR in lung tissues. The changes in transforming growth factor-beta1 (TGF-β1), tumour necrosis factor-α (TNF-α), interleukin-β1 (IL-β1) and nuclear factor kappa-β (NF-κβ) in serum were measured by ELISA. The tissue antioxidant status was determined biochemically. BLM administration caused pulmonary fibrosis as evidenced by increased levels of inflammatory mediators (TGF-β1, TNF-α, IL-β1 and NF-κβ) in serum (P < .05), elevated lipid peroxidation and nitric oxide and depleted endogenous antioxidants in lung tissue (P < .05). The expression levels of SIRT1 and AMPK were significantly decreased (P < .05), while the expression levels of CTGF and PDGF were increased significantly in the BLM group as compared to the control group (P < .05). These alterations were normalized by NAC intervention. NAC markedly attenuated the lung histopathological changes and reduced collagen deposition. These results suggest that NAC exerted an ameliorative effect against BLM-induced oxidative damage and pulmonary fibrosis via SIRT1/ AMPK/ NF-κβ pathways.

Corticosteroids in Acute Lung Injury: The Dilemma Continues

Acute lung injury (ALI) represents a serious heterogenous pulmonary disorder with high mortality. Despite improved understanding of the pathophysiology, the efficacy of standard therapies such as lung-protective mechanical ventilation, prone positioning and administration of neuromuscular blocking agents is limited. Recent studies have shown some benefits of corticosteroids (CS). Prolonged use of CS can shorten duration of mechanical ventilation, duration of hospitalization or improve oxygenation, probably because of a wide spectrum of potentially desired actions including anti-inflammatory, antioxidant, pulmonary vasodilator and anti-oedematous effects. However, the results from experimental vs. clinical studies as well as among the clinical trials are often controversial, probably due to differences in the designs of the trials. Thus, before the use of CS in ARDS can be definitively confirmed or refused, the additional studies should be carried on to determine the most appropriate dosing, timing and choice of CS and to analyse the potential risks of CS administration in various groups of patients with ARDS.

Budesonide instillation immediately after reperfusion ameliorates ischemia/reperfusion-induced injury in the transplanted lung of rat

PURPOSE

Lung ischemia-reperfusion injury (LIRI) after lung transplantation can lead to primary graft dysfunction. Budesonide can improve endothelial function to reduce lung injury. This study was aimed to examine the effects of budesonide on LIRI and potential mechanisms.

METHODS

Wistar rats were randomized and transplanted with syngeneic left lung or received the sham surgery. The recipients were instilled with saline or budesonide immediately after reperfusion. The mean arterial pressure (MAP), blood gas, and lung histology were analyzed. The ratios of wet to dry lung weights, the levels of total proteins, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and IL-10, and neutrophil elastase in bronchoalveolar lavage fluid (BALF) were measured. The levels of malondialdehyde (MDA), myeloperoxidase (MPO), and xanthine oxidase (XO) in the lung, and the levels of plasma lymphocyte function-associated antigen (LFA)-1 and P-selectin were determined.

RESULTS

Compared with the saline group, treatment with budesonide significantly increased blood PaO₂, but reduced PaCO₂, and mitigated lung damages after reperfusion, the levels of BALF proteins, and the ratios of wet to dry lung weights in rats. Furthermore, treatment with budesonide significantly decreased the levels of MDA, MPO, and XO in the lung and the levels of TNF-α, IL-1β, IL-6, and neutrophil elastase, but increased IL-10 in the BALF, accompanied by significantly reduced levels of serum P-selectin and LFA-1 in rats.

CONCLUSIONS

Budesonide effectively mitigated LIRI and ameliorated the lung function by attenuating oxidative stress and inflammation following syngeneic lung transplantation.

Fifty Years of Research in ARDS. Is Acute Respiratory Distress Syndrome a Preventable Disease?

Despite significant advances in our understanding and management of patients with acute respiratory distress syndrome (ARDS), the morbidity and mortality from ARDS remains high. Given the limited number of effective treatments for established ARDS, the strategic focus of ARDS research has shifted toward identifying patients with or at high risk of ARDS early in the course of the underlying illness, when strategies to reduce the development and progression of ARDS and associated organ failures can be systematically evaluated. In this review, we summarize the rationale, current evidence, and future directions in ARDS prevention.

Budesonide Attenuates Ventilator-induced Lung Injury in a Rat Model of Inflammatory Acute Respiratory Distress Syndrome

BACKGROUND AND AIMS

Patients with acute respiratory distress syndrome (ARDS) are particularly susceptible to ventilator-induced lung injury (VILI). This study investigated the effect of budesonide on VILI in a rat model of inflammatory ARDS.

METHODS

Forty eight rats were randomized into three groups (n = 16 each): sham group (S), endotoxin/ventilation group (LV), endotoxin/ventilation/budesonide group (LVB). Rats in the S group received anesthesia only. Rats in the LV and LVB groups received endotoxin to simulate ARDS and were mechanically ventilated for 4 h (tidal volume 30 mL/kg). Rats in the LVB group received budesonide 1 mg, and rats in the LV group received saline in airway. PaO2/FiO2, lung wet-to-dry weight ratios, inflammatory factors in serum and bronchoalveolar lavage fluid (BALF), histopathologic analysis of lung tissue, and survival were examined.

RESULTS

PaO2/FiO2 was significantly increased in rats in the LVB group compared to the LV group. Total cell count, macrophages, and neutrophils in BALF, and levels of intercellular adhesion molecule (ICAM)-1, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-8 in BALF and serum were significantly decreased in rats in the LVB group compared to the LV group, whereas levels of IL-10 in BALF and serum were significantly increased. Histopathological changes of lung injury and apoptosis were reduced, and survival was increased in rats in the LVB group compared to the LV group.

CONCLUSIONS

Budesonide ameliorated VILI in a rat model of inflammatory ARDS.

Inhalation therapies in acute respiratory distress syndrome

The defining features of acute respiratory distress syndrome (ARDS) are an excessive inflammatory respiratory response associated with high morbidity and mortality. Treatment consists mainly of measures to avoid worsening lung injury and cannot reverse the underlying pathophysiological process. New pharmacological agents have shown promising results in preclinical studies; however, they have not been successfully translated to patients with ARDS. The lack of effective therapeutic interventions has resulted in a recent interest in strategies to prevent ARDS with treatments delivering medications directly to the lungs by inhalation and nebulization, hopefully minimizing systemic adverse events. We analyzed the effect of different aerosolized drugs such as bronchodilators, corticosteroids, pulmonary vasodilators, anticoagulants, mucolytics and surfactant. New therapeutic strategies and ongoing trials using carbon monoxide (CO) and AP301 peptide are also briefly reviewed.

Randomized Clinical Trial of a Combination of an Inhaled Corticosteroid and Beta Agonist in Patients at Risk of Developing the Acute Respiratory Distress Syndrome

OBJECTIVES

Effective pharmacologic treatments directly targeting lung injury in patients with the acute respiratory distress syndrome are lacking. Early treatment with inhaled corticosteroids and beta agonists may reduce progression to acute respiratory distress syndrome by reducing lung inflammation and enhancing alveolar fluid clearance.

DESIGN

Double-blind, randomized clinical trial (ClinicalTrials.gov: NCT01783821). The primary outcome was longitudinal change in oxygen saturation divided by the FIO2 (S/F) through day 5. We also analyzed categorical change in S/F by greater than 20%. Other outcomes included need for mechanical ventilation and development of acute respiratory distress syndrome.

SETTING

Five academic centers in the United States.

PATIENTS

Adult patients admitted through the emergency department at risk for acute respiratory distress syndrome.

INTERVENTIONS

Aerosolized budesonide/formoterol versus placebo bid for up to 5 days.

MEASUREMENTS AND MAIN RESULTS

Sixty-one patients were enrolled from September 3, 2013, to June 9, 2015. Median time from presentation to first study drug was less than 9 hours. More patients in the control group had shock at enrollment (14 vs 3 patients). The longitudinal increase in S/F was greater in the treatment group (p = 0.02) and independent of shock (p = 0.04). Categorical change in S/F improved (p = 0.01) but not after adjustment for shock (p = 0.15). More patients in the placebo group developed acute respiratory distress syndrome (7 vs 0) and required mechanical ventilation (53% vs 21%).

CONCLUSIONS

Early treatment with inhaled budesonide/formoterol in patients at risk for acute respiratory distress syndrome is feasible and improved oxygenation as assessed by S/F. These results support further study to test the efficacy of inhaled corticosteroids and beta agonists for prevention of acute respiratory distress syndrome.

Effect of nebulized budesonide on respiratory mechanics and oxygenation in acute lung injury/acute respiratory distress syndrome: Randomized controlled study

Background:

We tested the hypothesis that nebulized budesonide would improve lung mechanics and oxygenation in patients with early acute lung injury (ALI) and/or acute respiratory distress syndrome (ARDS) during protective mechanical ventilation strategy without adversely affecting systemic hemodynamics.

Methods:

Patients with ALI/ARDS were included and assigned into two groups; budesonide group (30 cases) in whom 1 mg–2 ml budesonide suspension was nebulized through the endotracheal tube and control group (30 cases) in whom 2 ml saline (placebo) were nebulized instead of budesonide. This regimen was repeated every 12 h for three successive days alongside with constant ventilator settings in both groups. Hemodynamics, airway pressures, and PaO₂/FiO₂ were measured throughout the study period (72 h) with either nebulized budesonide or saline. Furthermore, tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), and interleukin-6 (IL-6) were analyzed serologically as markers of inflammation at pre- and post-nebulization sessions.

Results:

We found a significant difference between the two groups regarding PaO₂/FiO₂ (P = 0.023), peak (P = 0.021), and plateau (P = 0.032) airway pressures. Furthermore, TNF-α, IL-1β, and IL-6 were significantly reduced after budesonide nebulizations. No significant difference was found between the two groups regarding hemodynamic variables.

Conclusion:

Nebulized budesonide improved oxygenation, peak, and plateau airway pressures and significantly reduced inflammatory markers (TNF-α, IL-1β and IL-6) without affecting hemodynamics.

Trial Registry:

Australian New Zealand Clinical Trial Registry (ANZCTR) at the number: ACTRN12615000373572.

Budesonide ameliorates lung injury induced by large volume ventilation

Background

Ventilation-induced lung injury (VILI) is a health problem for patients with acute respiratory dysfunction syndrome. The aim of this study was to investigate the effectiveness of budesonide in treating VILI.

Methods

Twenty-four rats were randomized to three groups: a ventilation group, ventilation/budesonide group, and sham group were ventilated with 30 ml/kg tidal volume or only anesthesia for 4 hor saline or budesonide airway instillation immediately after ventilation. The PaO₂/FiO₂and wet-to-dry weight ratios, protein concentration, neutrophil count, and neutrophil elastase levels in bronchoalveolar lavage fluid (BALF) and the levels of inflammation-related factors were examined. Histological evaluation of and apoptosis measurement inthe lung were conducted.

Results

Compared with that in the ventilation group, the PaO₂/FiO₂ ratio was significantly increased by treatment with budesonide. The lung wet-to-dry weight ratio, total protein, neutrophil elastase level, and neutrophilcount in BALF were decreased in the budesonide group. The BALF and plasma tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, intercellular adhesion molecule (ICAM)-1, and macrophage inflammatory protein (MIP)-2 levels were decreased, whereas the IL-10 level was increased in the budesonide group. The phosphorylated nuclear factor (NF)-kBlevels in lung tissue were inhibited by budesonide. The histological changes in the lung and apoptosis were reduced by budesonide treatment. Bax, caspase-3, and cleaved caspase-3 were down-regulated, and Bcl-2 was up-regulated by budesonide.

Conclusions

Budesonide ameliorated lung injury induced by large volume ventilation, likely by improving epithelial permeability, decreasing edema, inhibiting local and systemic inflammation, and reducing apoptosis in VILI.

N-acetylcysteine advancement of surfactant therapy in experimental meconium aspiration syndrome: possible mechanisms

Meconium aspiration syndrome (MAS) is meconium-induced respiratory failure of newborns associated with activation of inflammatory and oxidative pathways. For severe MAS, exogenous surfactant treatment is used which improves respiratory functions but does not treat the inflammation. Oxidative process can lead to later surfactant inactivation; hence, surfactant combination with antioxidative agent may enhance the therapeutic effect. Young New Zealand rabbits were instilled by meconium suspension and treated by surfactant alone, N-acetylcysteine (NAC) alone or by their combination and oxygen-ventilated for 5 h. Blood samples were taken before and 30 min after meconium application and 30 min, 1, 3 and 5 h after the treatment for evaluating of oxidative damage, total leukocyte count, leukocyte differential count and respiratory parameters. Leukocyte differential was assessed also in bronchoalveolar lavage fluid. NAC alone had only mild therapeutic effect on MAS. However, the combination of NAC and surfactant facilitated rapid onset of therapeutic effect in respiratory parameters (oxygenation index, PaO(2)/FiO(2)) compared to surfactant alone and was the only treatment which prevented neutrophil migration into the lungs, oxidative damage and lung edema. Moreover, NAC suppressed IL-8 and IL-beta formation and thus seems to be favorable agent for improving surfactant therapy in MAS.

Emerging therapies for the prevention of acute respiratory distress syndrome

The development of acute respiratory distress syndrome (ARDS) carries significant risk of morbidity and mortality. To date, pharmacological therapy has been largely ineffective for patients with ARDS. We present our personal review aimed at outlining current and future directions for the pharmacological prevention of ARDS. Several available risk-stratification or prediction score strategies for identification of patients at risk of ARDS have been reported. Although not ready for clinical everyday use, they are and will be instrumental in the ongoing and future trials of pharmacoprevention of ARDS.Several systemic medications established the potential role in ARDS prevention based on the preclinical studies and observational data. Due to potential for systemic adverse effects to neutralize any pharmacological benefits of systemic therapy, inhaled medications appear particularly attractive candidates for ARDS prevention. This is because of their direct delivery to the site of proposed action (lungs), while the pulmonary epithelial surface is still functional.We postulate that overall morbidity and mortality rates from ARDS in the future will be contingent upon decreasing the overall incidence of ARDS through effective identification of those at risk and early application of proven supportive care and pharmacological interventions.

Budesonide inhalation ameliorates endotoxin-induced lung injury in rabbits

Acute respiratory distress syndrome (ARDS) is a serious clinical problem that has a 30-50% mortality rate. Budesonide has been used to reduce lung injury. This study aims to investigate the effects of nebulized budesonide on endotoxin-induced ARDS in a rabbit model. Twenty-four rabbits were randomized into three groups. Rabbits in the control and budesonide groups were injected with endotoxin. Thereafter, budesonide or saline was instilled, ventilated for four hours, and recovered spontaneous respiratory. Peak pressure, compliance, and PaO2/FiO2 were monitored for 4 h. After seven days, PaO2/FiO2 ratios were measured. Wet-to-dry weight ratios, total protein, neutrophil elastase, white blood cells, and percentage of neutrophils in BALF were evaluated. TNF-α, IL-1β, IL-8, and IL-10 in BALF were detected. Lung histopathologic injury and seven-day survival rate of the three groups were recorded. Peak pressure was downregulated, but compliance and PaO2/FiO2 were upregulated by budesonide. PaO2/FiO2 ratios significantly increased due to budesonide. Wet-to-dry weight ratios, total protein, neutrophil elastase, white blood cells and percentage of neutrophils in BALF decreased in the budesonide group. TNF-α, IL-1β, and IL-8 levels decreased in BALF, while IL-10 levels increased in the budesonide group. Lung injuries were reduced and survival rate was upregulated by budesonide. Budesonide effectively ameliorated respiratory function, attenuated endotoxin-induced lung injury, and improved the seven-day survival rate.

Disruption of cytochrome P4501A2 in mice leads to increased susceptibility to hyperoxic lung injury

Hyperoxia contributes to acute lung injury in diseases such as acute respiratory distress syndrome. Cytochrome P450 (CYP) 1A enzymes have been implicated in hyperoxic lung injury, but the mechanistic role of CYP1A2 in pulmonary injury is not known. We hypothesized that mice lacking the gene Cyp1a2 (which is predominantly expressed in the liver) will be more sensitive to lung injury and inflammation mediated by hyperoxia and that CYP1A2 will play a protective role by attenuating lipid peroxidation and oxidative stress in the lung. Eight- to ten-week-old WT (C57BL/6) or Cyp1a2(-/-) mice were exposed to hyperoxia (>95% O2) or maintained in room air for 24-72 h. Lung injury was assessed by determining the ratio of lung weight/body weight (LW/BW) and by histology. Extent of inflammation was determined by measuring the number of neutrophils in the lung as well as cytokine expression. The Cyp1a2(-/-) mice under hyperoxic conditions showed increased LW/BW ratios, lung injury, neutrophil infiltration, and IL-6 and TNF-α levels and augmented lipid peroxidation, as evidenced by increased formation of malondialdehyde- and 4-hydroxynonenal-protein adducts and pulmonary isofurans compared to WT mice. In vitro experiments showed that the F2-isoprostane PGF2-α is metabolized by CYP1A2 to a dinor metabolite, providing evidence for a catalytic role for CYP1A2 in the metabolism of F2-isoprostanes. In summary, our results support the hypothesis that hepatic CYP1A2 plays a critical role in the attenuation of hyperoxic lung injury by decreasing lipid peroxidation and oxidative stress in vivo.

Preventing ARDS: progress, promise, and pitfalls

Advances in critical care practice have led to a substantial decline in the incidence of ARDS over the past several years. Low tidal volume ventilation, timely resuscitation and antimicrobial administration, restrictive transfusion practices, and primary prevention of aspiration and nosocomial pneumonia have likely contributed to this reduction. Despite decades of research, there is no proven pharmacologic treatment of ARDS, and mortality from ARDS remains high. Consequently, recent initiatives have broadened the scope of lung injury research to include targeted prevention of ARDS. Prediction scores have been developed to identify patients at risk for ARDS, and clinical trials testing aspirin and inhaled budesonide/formoterol for ARDS prevention are ongoing. Future trials aimed at preventing ARDS face several key challenges. ARDS has not been validated as an end point for pivotal clinical trials, and caution is needed when testing toxic therapies that may prevent ARDS yet potentially increase mortality.

The discovery of potent and selective non-steroidal glucocorticoid receptor modulators, suitable for inhalation

We report the discovery of highly potent and selective non-steroidal glucocorticoid receptor modulators with PK properties suitable for inhalation. A high throughput screen of the AstraZeneca compound collection identified sulfonamide 3 as a potent non-steroidal glucocorticoid receptor ligand. Further optimization of this lead generated indazoles 30 and 48 that were progressed to characterization in in vivo models. X-ray crystallography was used to gain further insight into the binding mode of selected ligands.

Prehospital use of inhaled steroids and incidence of acute lung injury among patients at risk

PURPOSE

Inhaled corticosteroids (ICSs) attenuated lung injury in animal studies. We investigated the association between prehospital ICS and incidence of acute lung injury (ALI) among patients at risk.

METHODS

In this ancillary analysis of the large multicenter Lung Injury Prediction Study cohort, we developed a propensity score for prehospital ICS use followed by matching, for all patients and for a subgroup of patients with at least 1 risk factor for direct pulmonary injury. The primary outcome was ALI; secondary outcomes included acute respiratory distress syndrome, need for invasive mechanical ventilation, and hospital mortality.

RESULTS

Of the 5126 patients, 401 (8%) were using ICS. Acute lung injury developed in 343 (7%). The unadjusted incidence of ALI was 4.7% vs 6.9% (P = .12) among those in ICS compared with non-ICS group. In the "direct" lung injury subgroup, the unadjusted incidence of ALI was 4.1% vs 10.6% (P = 0.006). After propensity matching, the estimated effect for ALI in the whole cohort was 0.69 (95% confidence interval, 0.39-1.2; P = .18), and that in the direct subgroup was 0.56 (95% confidence interval, 0.22-1.46; P = .24).

CONCLUSIONS

Preadmission use of ICS in a hospitalized population of patients at risk for ALI was not significantly associated with a lower incidence of ALI once controlled by comprehensive propensity-matched analysis.

Effects of phosphoinositide 3-kinase on protease-induced acute and chronic lung inflammation, remodeling, and emphysema in rats

BACKGROUND

Phosphoinositide 3-kinase (PI3K) plays an important role in tissue inflammatory reactions and fibrotic processes. The objective of this study was to evaluate the potential mechanism and therapeutic effects of PI3K inhibitor on pancreatic elastase (PE)-induced acute and chronic lung inflammation, edema, and injury.

METHODS

Rats were terminated at 7 or 28 days after an intratracheal challenge with PE and intranasal instillation with a PI3K inhibitor, SHBM1009. Alterations of airway epithelial cells and myofibroblasts were studied in vitro.

MEASUREMENTS

Lung inflammation, edema, and injury; emphysema; and tissue remodeling were measured after PE instillation with or without treatment with PI3K inhibitor and budesonide. Cellular biologic functions were monitored.

RESULTS

SHBM1009 could prevent PE-induced acute lung inflammation, edema, and injury, and chronic lung inflammation, remodeling, and emphysema. Different patterns of inhibitory effects of SHBM1009 and BEZ235, a dual PI3K/mechanistic target of rapamycin inhibitor, on PE-challenged epithelial cells were observed. PE per se reduced epithelial cell proliferation and stability through the inhibition of cell division rather than promoting cell death, in dose- and time-dependent patterns. Effects of PI3K inhibitors on cells were associated with the severity of PE challenges.

CONCLUSIONS

PI3K plays a critical role in the development of acute and chronic lung injury, including the process of tissue remodeling and emphysema. PI3K inhibitors could be new therapeutic alternatives for chronic lung diseases.

Insulin up-regulates epithelial sodium channel in LPS-induced acute lung injury model in rats by SGK1 activation

Activity of the epithelial sodium channels (ENaCs) in the lung tissue plays a critical role on sodium/fluid homeostasis and the lung fluid clearance. The serum- and glucocorticoid-inducible kinase-1 (SGK1), one of the critical regulation proteins of ENaC, is activated by insulin and growth factors possibly through 3-phosphoinositide-dependent kinase PDK1 or/and phosphatidylinositol 3-kinase (PI3K). However, it is uncertain whether insulin shows its stimulatory action on ENaC by activation of SGK1 in lipopolysaccharide (LPS)-induced acute lung injury (ALI) condition. In our study, Wistar rats were injected with LPS to induce ALI. Evans blue dye albumin (EBA) concentration was used to measure pulmonary oedema. For detecting the ratio of phospho-SGK1/SGK1 and α-ENaC protein, Western blot was performed. Real-time polymerase chain reaction (RT-PCR) was used to assess α-ENaC messenger RNA (mRNA). Immunohistochemistry was used to locate and quantitate α-ENaC expression. The EBA concentration was markedly increased by LPS alone but significantly reduced in rats that also received insulin injection. The ratio of phospho-SGK1/SGK1 was raised significantly in the insulin group and insulin+LPS group, compared with the control group and the LPS group, respectively. Furthermore, α-ENaC was up-regulated by insulin treatment. Simultaneously, injection with LPS significantly reduced α-ENaC expression. These findings demonstrated that insulin up-regulates ENaC in vivo possibly resulting from activation of SGK1.

N-acetylcysteine attenuates ventilator-induced lung injury in an isolated and perfused rat lung model

N-acetylcysteine (NAC) suppresses the generation of reactive oxygen species (ROS) that are implicated in ventilator-induced lung injury (VILI). We thus hypothesised that NAC attenuates VILI. VILI was induced by mechanical ventilation with a tidal volume (Vt) of 15mlkg(-1) in isolated and perfused rat lung. NAC was administered in the perfusate prior to the onset of mechanical ventilation. A group ventilated with low Vt of 5mlkg(-1) served as control. Haemodynamics, lung injury indices, inflammatory responses and activation of apoptotic pathways were determined upon completion of the mechanical ventilation. There was an increase in lung permeability and lung weight gain after mechanical ventilation with high Vt, compared to low Vt. The levels of inflammatory cytokines including interleukin-1β (IL-1β), tumour necrosis factor-α (TNF-α) and macrophage inflammatory protein-2 (MIP-2) increased in lung lavage fluids; the concentrations of H(2)O(2) were higher in lung lavage fluids, and the expression of myeloperoxidase (MPO), JNK, P38, pAKT and caspase-3 in lung tissue was greater in the high Vt than in the low Vt group. The concentrations of glutathione (GSH) in lung tissue were higher in low Vt than those in high Vt. The administration of NAC increased GSH, attenuated ROS, cytokines, MPO, JNK, pAKT and caspase-3 and lung permeability associated with decreased activation of nuclear factor-κB. VILI is associated with inflammatory responses including the generation of ROS, cytokines and the activation of mitogen-activated protein kinase cascade. The administration of NAC attenuates the inflammatory responses, apoptosis and VILI in the isolated, perfused rat lung model.

Effects of Schisandra chinensis Baillon (Schizandraceae) on lipopolysaccharide induced lung inflammation in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Schisandra chinensis Baillon (Sc), an anti-inflammatory herb that has been used in traditional Chinese medicine for thousands of years, is frequently used to treat upper respiratory tract infections.

AIM OF THE STUDY

This study was conducted to evaluate the ability of a water extract of Sc to prevent airway inflammation both in vitro and in vivo.

MATERIALS AND METHODS

Human lung alveolar epithelial-derived A549 cells were stimulated with to interleukin-1β, tumor necrosis factor-α, and interferon-γ (IL-1β, TNF-α, and INF-γ; cytokine mixture; CM) and treated with Sc extracts. They were then evaluated using nitric oxide (NO), IL-8 and monocyte chemotactic protein-1 (MCP-1) secretions. In the in vivo study, BALB/c mice were challenged with lipopolysaccharide (LPS) to induce acute airway inflammation. After this challenge, the mice were treated with Sc extracts (10, 50 and 100mg/kg) by oral administration, and inflammatory cells in the bronchoalveolar lavage (BAL) fluid were counted. IL-6 and TNF-α secretions were measured using an enzyme-linked immunosorbent assay. Lung tissues of the LPS treated mice were prepared and stained with hematoxylin and eosin (HE) for histological examination.

RESULTS

In the A549 cells, Sc extracts dose-dependently and significantly inhibited CM-induced NO production and reduced IL-8 and MCP-1 secretions. Sc extracts efficiently suppressed neutrophil and macrophage infiltrations of lung tissues and increased IL-6 and TNF-α levels in BAL fluid in LPS-instilled BALB/c mice. In addition, Sc extracts treatment inhibited pathologic progress in the lung tissues, as confirmed by H&E staining. These findings indicate that Sc extracts could be potentially useful for the treatment of acute lung inflammation and acute lung injury.

Efficacy of budesonide and interleukin-10 in an experimental rat model with isolated bilateral pulmonary contusion created by blunt thoracic trauma

OBJECTIVES

In our study, we aimed to investigate the anti-inflammatory mediator effects of budesonide (BS), an inhaled corticosteroid and interleukin-10 (IL-10) on a pulmonary contusion in an experimental rat model in which an isolated bilateral pulmonary contusion was created by blunt thoracic trauma.

METHODS

Fifty-five male Sprague-Dawley rats were used in the study. Sham, control, BS and IL-10 groups were created. A pulmonary contusion was created by performing isolated blunt thoracic trauma in all groups except for the sham group. The trauma's severity was determined as 1.45 J. BS and IL-10 were administered orogastrically to the respective groups 30 min before trauma, and orogastrically and intraperitoneally, respectively, on the first and second days after the trauma. Only the blunt thoracic trauma was performed for the control group. SatO(2), PaO(2) and PaCO(2), blood glutathione, malondialdehyde (MDA) and tumour necrosis factor-α (TNFα) values were recorded on the zeroth, first, second and third days. The histopathological examination and the bronchoalveolar lavage cell count were performed on pulmonary tissues.

RESULTS

Blood gas analysis revealed that SatO(2) and PaO(2) values on the first and second days were significantly lower in the control, BS and IL-10 groups compared with the sham group (P < 0.05). The SatO(2) and PaO(2) values on the third day in the BS and IL-10 groups were higher than in the control group (P < 0.05). The mean MDA in the control group was higher than in the sham, BS and IL-10 groups (P < 0.05). The mean TNFα in the control group was higher than in the sham, BS and IL-10 groups (P < 0.05). Pulmonary pathology scoring in the control group was observed to be higher than in the sham, BS and IL-10 groups (P < 0.05).

CONCLUSION

In this rat experiment model in which an isolated pulmonary contusion was created by blunt trauma, BS and IL-10 were observed to reduce contusion severity in the lung and minimize the inflammatory reaction.

Clinical review: Early treatment of acute lung injury--paradigm shift toward prevention and treatment prior to respiratory failure

Acute lung injury (ALI) remains a major cause of morbidity and mortality in critically ill patients. Despite improved understanding of the pathogenesis of ALI, supportive care with a lung protective strategy of mechanical ventilation remains the only treatment with a proven survival advantage. Most clinical trials in ALI have targeted mechanically ventilated patients. Past trials of pharmacologic agents may have failed to demonstrate efficacy in part due to the resultant delay in initiation of therapy until several days after the onset of lung injury. Improved early identification of at-risk patients provides new opportunities for risk factor modification to prevent the development of ALI and novel patient groups to target for early treatment of ALI before progression to the need for mechanical ventilation. This review will discuss current strategies that target prevention of ALI and some of the most promising pharmacologic agents for early treatment of ALI prior to the onset of respiratory failure that requires mechanical ventilation.

Inhalation studies for the safety assessment of nanomaterials: status quo and the way forward

While technical and medical potential offered by nanotechnologies increase, the safety assessment of engineered nanomaterials (NMs) needs to follow this pace. Inhalation is a major route of occupational and environmental exposure, and is most relevant for most of the respective safety assessment studies. Control and generation of aerosol from the test materials for this route of administration are technically demanding, and not surprisingly, there are relatively few NMs tested in toxicokinetic, short-term, and subchronic inhalation studies. These studies were in part adapted to the peculiarities of inhaled NMs, but few were also conducted according to organization for economic co-operation and development (OECD) test guidelines. Inhalation studies on the potential to develop chronic diseases, or studies to check the potential analogy to cardiovascular diseases associated with adverse health effects from ambient air pollution, are largely missing. On the way forward, appropriate inhalation studies need to be performed on a number of NMs to assess their hazards and to provide a sound database for correlation and validation of alternative in vitro methods. Moreover, these studies can potentially aid in the grouping of different NMs based on their biokinetics or biological effects. For carcinogenic and cardiovascular effects, research studies are needed to verify-or disprove-the relevance and the mechanisms by which NMs contribute to these effects.

Anti-inflammatory effects of LASSBio-998, a new drug candidate designed to be a p38 MAPK inhibitor, in an experimental model of acute lung inflammation

We investigated the effects of LASSBio-998 (L-998), a compound designed to be a p38 MAPK (mitogen-activated protein kinase) inhibitor, on lipopolysaccharide (LPS)-induced acute lung inflammation in vivo. BALB/c mice were challenged with aerosolized LPS inhalation (0.5 mg/ml) 4 h after oral administration of L-998. Three hours after LPS inhalation, bronchoalveolar lavage fluid was obtained to measure the levels of the proinflammatory cytokines TNF-α (tumor necrosis factor-α) and IL-1 (interleukin-1) and the chemokines MCP-1 (monocyte chemoattractant protein-1) and KC (keratinocyte chemoattractant). In addition, neutrophil infiltration and p38 MAPK phosphorylation was measured. L-998 inhibited LPS-induced production of TNF-α and IL-1β and did not alter KC and MCP-1 levels. Furthermore, L-998 also significantly decreased neutrophil accumulation in lung tissues. As expected, L-998 diminished p38 MAPK phosphorylation and reduced acute lung inflammation. Inhibition of p38 MAPK phosphorylation by L-998 was also demonstrated in LPS-challenged murine C57BL/6 peritoneal macrophages in vitro, with concentration-dependent effects. L-998 suppressed LPS-induced lung inflammation, most likely by inhibition of the cytokine-p38 MAPK pathway, and we postulate that L-998 could be a clinically relevant anti-inflammatory drug candidate.

Models and mechanisms of acute lung injury caused by direct insults

Acute lung injury (ALI) and its more severe form acute respiratory distress syndrome (ARDS) are life-threatening diseases that are characterized by acute onset, pulmonary inflammation, oedema due to increased vascular permeability and severe hypoxemia. Clinically, ARDS can be divided into ARDS due to direct causes such as pneumonia, aspiration or injurious ventilation, and due to extrapulmonary indirect causes such as sepsis, severe burns or pancreatitis. In order to identify potential therapeutic targets, we asked here whether common molecular mechanisms can be identified that are relevant in different models of the direct form of ALI/ARDS. To this end, we reviewed three widely used models: (a) one based on a biological insult, i.e. instillation of bacterial endotoxins; (b) one based on a chemical insult, i.e. instillation of acid; and (c) one based on a mechanical insult, i.e. injurious ventilation. Studies were included only if the mediator or mechanism of interest was studied in at least two of the three animal models listed above. As endpoints, we selected neutrophil sequestration, permeability, hypoxemia (physiological dysfunction) and survival. Our analysis showed that most studies have focused on mechanisms of pulmonary neutrophil sequestration and models with moderate forms of oedema. The underlying mechanisms that involve canonical inflammatory pathways such as MAP kinases, CXCR2 chemokines, PAF, leukotrienes, adhesions molecules (CD18, ICAM-1) and elastase have been defined relatively well. Further mechanisms including TNF, DARC, HMGB1, PARP, GADD45 and collagenase are under investigation. Such mechanisms that are shared between the three ALI models may represent viable therapeutic targets. However, only few studies have linked these pathways to hypoxemia, the most important clinical aspect of ALI/ARDS. Since moderate oedema does not necessarily lead to hypoxemia, we suggest that the clinical relevance of experimental studies can be further improved by putting greater emphasis on gas exchange.

Preventive and therapeutic effects of phosphoinositide 3-kinase inhibitors on acute lung injury

BACKGROUND

Phosphoinositide 3-kinases (PI3Ks) are involved in a number of biologic responses. Recent preclinical studies demonstrated that the PI3K-dominant signal pathway could play an important role in the development of acute lung injury, although the mechanism remains unclear.

METHODS

CD-1 mice were administered different PI3K inhibitors either intranasally or intragastrically once a day for 3 days before intratracheal instillation of lipopolysaccharide at 4 h and 24 h. Effects of SHBM1009 on lipopolysaccharide-induced capillary permeability, leukocyte distribution and activation, and epithelial cell function were measured. Therapeutic effects of SHBM1009 on pancreatic elastase-induced lung injury were evaluated in rats.

RESULTS

The data demonstrated that the local delivery of PI3K inhibitors played more effective roles in the prevention of endotoxin-induced lung injury than the systemic delivery. The preventive effects of PI3K inhibitors varied most likely because of chemical properties, targeting sites, and pharmacokinetics. The local PI3K inhibitors prevented both endotoxin- and elastase-induced lung injury in mice and rats, possibly through directly inhibiting or inactivating the function of airway epithelial cells, which could not produce chemoattractant factors to activate neutrophils and macrophages.

CONCLUSIONS

PI3K may be a therapeutic target for lung injury, and local delivery of PI3K inhibitors may be one of the optimal approaches for the therapy.

The value of the lipopolysaccharide-induced acute lung injury model in respiratory medicine

Acute lung injury/acute respiratory distress syndrome (ALI/ARDS) is a syndrome characterized by pulmonary edema and acute inflammation. Lipopolysaccharide (LPS), a major component in Gram-negative bacteria, has been used to induce ALI/ARDS. LPS-induced animal models highlight ways to explore mechanisms of multiple diseases and provide useful information on the discovery of novel biomarkers and drug targets. However, each model has its own merits and drawbacks. The goal of this article is to summarize and evaluate the results of experimental findings in LPS-induced ALI/ARDS, and the possible mechanisms and treatments elucidated. Advantages and disadvantages of such models in pulmonary research and new directions for future investigations are also discussed.

Glucocorticoids in the treatment of neonatal meconium aspiration syndrome

Meconium aspiration syndrome is a serious neonatal disease with complex pathophysiology. With respect to the contribution of meconium-induced lung edema, inflammation and vasoconstriction on the course of the disease, glucocorticoids are increasingly used in the treatment of MAS despite the fact that principal questions on the choice of GCs derivative, mode of delivery and dosing have not been answered yet. To bring a complex insight into the topic, this article reviews the pathomechanisms of MAS, mechanisms of action of GCs, as well as the advantages and disadvantages of GCs administration in experimental models and newborns with MAS.

1H and hyperpolarized 3He magnetic resonance imaging clearly detect the preventative effect of a glucocorticoid on endotoxin-induced pulmonary inflammation in vivo

Introduction: Proton (1H) magnetic resonance imaging (MRI) can be utilized to quantify pulmonary edema in endotoxin-induced pulmonary inflammation and hyperpolarized (HP) 3He MRI can assess pulmonary ventilation. Neither of the methods has been applied to assess the impact of a drug on endotoxin-induced pulmonary inflammation in vivo. The aim of the current study was to evaluate the capability of 1H and HP 3He MRI to assess the effects of a glucocorticoid on endotoxin-induced pulmonary inflammation in vivo.

Materials and Methods: Mice were exposed to an aerosol of either saline or endotoxin (5 mg/ml) for 10 min. Half of the endotoxin-exposed mice were pretreated with a glucocorticoid (budesonide 3 mg/kg; 2 times/day) and the other half with vehicle p.o. The first budesonide treatment was administered 1 h prior to the aerosol inhalation. Forty-eight hours after the aerosol exposure, the mice were anaesthetized for subsequent imaging. Hyperpolarized 3He was administered and axial MR images of the lungs obtained. Matching 1H MR images were then acquired. The mice were sacrificed and broncho-alveolar lavage (BAL) samples were harvested to determine total and cell differential counts. Results: The lesion volume on both 1H and 3He MRI, were markedly increased by endotoxin exposure (P<0.001). Budesonide strongly reduced lesion volume ( P<0.001). The BAL cell count correlated strongly with both 3He ( P<0.001; r = 0.96) and 1H lesion volumes ( P<0.001; r = 0.97).

Conclusions: Hyperpolarized 3He MRI and 1H MRI clearly visualized the preventative effect of budesonide on the impact of endotoxin on pulmonary ventilation and edema, respectively. The fact that ventilation defects on 3He MRI corresponded to findings from conventional 1H MRI, as well as to counts of BAL inflammatory cells suggests that these imaging techniques constitute promising tools for non-invasive monitoring of pulmonary inflammation in vivo.

Influência do pneumoperitônio nas funções hepática e renal e na liberação de citocinas pró-inflamatórias em modelo experimental de endotoxemia induzida por lipopolissacarídeo de Escherichia coli

RACIONAL: A videocirurgia pode apresentar complicações inerentes ao método e dentre elas destacam-se as relacionadas ao aumento da pressão na cavidade intra-abdominal. OBJETIVO: Analisar os efeitos do pneumoperitônio em modelo experimental de endotoxemia causada por lipopolissacarídeo. MÉTODO: Foram utilizados 32 ratos Wistar dos quais foi coletado sangue 24 horas prévias para obtenção dos valores de referência nas provas de função renal, hepática e do estado endotóxico (contagens total e diferencial de leucócitos, contagem de plaquetas e dosagens de lipopolissacarídeo, TNFα, IL6). A seguir os ratos foram separados em quatro grupos com oito: grupos controle inoculados com lipopolissacarídeo (10 mg/kg via intraperitoneal) e mantidos por quatro e 11 horas (C-LPS4 e C-LPS11). Grupo C-PP, submetido ao pneumoperitônio por CO2 por uma hora e mantido sob observação por seis horas. Grupo experimento (E) inoculados com 10 mg/kg de lipopolissacarídeo por via intraperitoneal, após quatro horas submetidos ao pneumoperitônio por CO2 por uma hora e mantidos sob observação por seis horas. Ao término destes períodos foram coletadas amostras de sangue para as mesmas avaliações iniciais. Utilizou-se o método de T-Student para as comparações dos resultados, com nível de significância de 0,05. RESULTADOS: Em comparação aos valores iniciais e aos grupos controle, o grupo E apresentou maiores valores nas dosagens de creatinina e uréia, bilirrubina direta, ALT e TAP, aumento nas dosagens de IL6, TNFα e diminuição de plaquetas, aumento de leucócitos e bastonetes e detecção de endotoxina circulante. CONCLUSÃO: O pneumoperitônio por dióxido de carbono induz aumentos na liberação de TNFα, IL6, piora das funções hepática e renal em modelo experimental de endotoxemia induzida por lipopolissacarídeo.

Development of budesonide microparticles using spray-drying technology for pulmonary administration: design, characterization, in vitro evaluation, and in vivo efficacy study

The purpose of this research was to generate, characterize, and investigate the in vivo efficacy of budesonide (BUD) microparticles prepared by spray-drying technology with a potential application as carriers for pulmonary administration with sustained-release profile and improved respirable fraction. Microspheres and porous particles of chitosan (drug/chitosan, 1:2) were prepared by spray drying using optimized process parameters and were characterized for different physicochemical parameters. Mass median aerodynamic diameter and geometric standard deviation for conventional, microspheres, and porous particles formulations were 2.75, 4.60, and 4.30 microm and 2.56, 1.75, and 2.54, respectively. Pharmacokinetic study was performed in rats by intratracheal administration of either placebo or developed dry powder inhalation (DPI) formulation. Pharmacokinetic parameters were calculated (Ka, Ke, T(max), C(max), AUC, and Vd) and these results indicated that developed formulations extended half life compared to conventional formulation with onefold to fourfold improved local and systemic bioavailability. Estimates of relative bioavailability suggested that developed formulations have excellent lung deposition characteristics with extended T(1/2) from 9.4 to 14 h compared to conventional formulation. Anti-inflammatory activity of BUD and developed formulations was compared and found to be similar. Cytotoxicity was determined in A549 alveolar epithelial cell line and found to be not toxic. In vivo pulmonary deposition of developed conventional formulation was studied using gamma scintigraphy and results indicated potential in vitro-in vivo correlation in performance of conventional BUD DPI formulation. From the DPI formulation prepared with porous particles, the concentration of BUD increased fourfold in the lungs, indicating pulmonary targeting potential of developed formulations.

N-acetylcysteine, a thiol antioxidant, decreases alveolar bone loss in experimental periodontitis in rats

BACKGROUND

The purpose of this study was to analyze the morphometric and histopathologic changes associated with experimental periodontitis in rats in response to systemic administration of N-acetylcysteine (NAC).

METHODS

Forty-three Wistar rats were divided into five experimental groups: non-ligated (NL) group (n = 10), ligature only (LO) group (n = 10), and groups that were administered NAC systemically (7, 35, or 70 mg/kg body weight per day [NAC7, NAC35, and NAC70 groups, respectively]; n = 8, 9, and 6). Silk ligatures were placed at the gingival margin of the lower first molars in a mandibular quadrant. The study duration was 11 days, and the animals were sacrificed at the end of this period. Changes in alveolar bone levels were measured clinically and tissues were histopathologically examined to assess the differences among the study groups.

RESULTS

At the end of 11 days, the alveolar bone loss was significantly higher in the LO group compared to NL, NAC7, NAC35, and NAC70 groups (P <0.05). There was no statistically significant difference in the osteoclast numbers among the study groups (P >0.05), whereas the effect of NAC was dose-dependent.

CONCLUSION

NAC prevented alveolar bone loss in the rat model, in a dose-dependent manner, when administered systemically.