Nilotinib ameliorates lipopolysaccharide-induced acute lung injury in rats

The present study aimed to investigate the effect of the new tyrosine kinase inhibitor, nilotinib on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in rats and explore its possible mechanisms. Male Sprague-Dawley rats were given nilotinib (10 mg/kg) by oral gavage twice daily for 1 week prior to exposure to aerosolized LPS. At 24 h after LPS exposure, bronchoalveolar lavage fluid (BALF) samples and lung tissue were collected. The lung wet/dry weight (W/D) ratio, protein level and the number of inflammatory cells in the BALF were determined. Optical microscopy was performed to examine the pathological changes in lungs. Malondialdehyde (MDA) content, superoxidase dismutase (SOD) and reduced glutathione (GSH) activities as well as nitrite/nitrate (NO₂⁻/NO₃⁻) levels were measured in lung tissues. The expression of inflammatory cytokines, tumor necrosis factor-α (TNF-α), transforming growth factor-β₁ (TGF-β₁) and inducible nitric oxide synthase (iNOS) were determined in lung tissues. Treatment with nilotinib prior to LPS exposure significantly attenuated the LPS-induced pulmonary edema, as it significantly decreased lung W/D ratio, protein concentration and the accumulation of the inflammatory cells in the BALF. This was supported by the histopathological examination which revealed marked attenuation of LPS-induced ALI in nilotinib treated rats. In addition, nilotinib significantly increased SOD and GSH activities with significant decrease in MDA content in the lung. Nilotinib also reduced LPS mediated overproduction of pulmonary NO₂⁻/NO₃⁻ levels. Importantly, nilotinib caused down-regulation of the inflammatory cytokines TNF-α, TGF-β₁ and iNOS levels in the lung. Taken together, these results demonstrate the protective effects of nilotinib against the LPS-induced ALI. This effect can be attributed to nilotinib ability to counteract the inflammatory cells infiltration and hence ROS generation and regulate cytokine effects.     

Role of inducible nitric oxide synthase-derived nitric oxide in lipopolysaccharide plus interferon-gamma-induced pulmonary inflammation

Exposure of mice to lipopolysaccharide (LPS) plus interferon-gamma (IFN-gamma) increases nitric oxide (NO) production, which is proposed to play a role in the resulting pulmonary damage and inflammation. To determine the role of inducible nitric oxide synthase (iNOS)-induced NO in this lung reaction, the responses of inducible nitric oxide synthase knockout (iNOS KO) versus C57BL/6J wild-type (WT) mice to aspirated LPS + IFN-gamma were compared. Male mice (8-10 weeks) were exposed to LPS (1.2 mg/kg) + IFN-gamma (5000 U/mouse) or saline. At 24 or 72 h postexposure, lungs were lavaged with saline and the acellular fluid from the first bronchoalveolar lavage (BAL) was analyzed for total antioxidant capacity (TAC), lactate dehydrogenase (LDH) activity, albumin, tumor necrosis factor-alpha (TNF-alpha), and macrophage inflammatory protein-2 (MIP-2). The cellular fraction of the total BAL was used to determine alveolar macrophage (AM) and polymorphonuclear leukocyte (PMN) counts, and AM zymosan-stimulated chemiluminescence (AM-CL). Pulmonary responses 24 h postexposure to LPS + IFN-gamma were characterized by significantly decreased TAC, increased BAL AMs and PMNs, LDH, albumin, TNF-alpha, and MIP-2, and enhanced AM-CL to the same extent in both WT and iNOS KO mice. Responses 72 h postexposure were similar; however, significant differences were found between WT and iNOS KO mice. iNOS KO mice demonstrated a greater decline in total antioxidant capacity, greater BAL PMNs, LDH, albumin, TNF-alpha, and MIP-2, and an enhanced AM-CL compared to the WT. These data suggest that the role of iNOS-derived NO in the pulmonary response to LPS + IFN-gamma is anti-inflammatory, and this becomes evident over time.     

Sitagliptin exerts anti-inflammatory and anti-allergic effects in ovalbumin-induced murine model of allergic airway disease

Sitagliptin, a new oral glucose lowering medication, is used for treatment of type 2 diabetes mellitus. The anti-inflammatory property of sitagliptin is reported, yet no studies have been done on asthma. In the present study, the effect of sitagliptin on allergic asthma was investigated using ovalbumin (OVA)-induced asthma model in mice. Swiss male albino mice sensitized and challenged to ovalbumin were treated with sitagliptin (8?mg/kg administered orally twice a day). Drug treatment was done on each day from days 16 to 23, 1?h before the challenge on the days of challenge. Sitagliptin treatment markedly decreased inflammatory cell accumulation in bronchoalveolar lavage (BAL) fluid and in the lungs, as revealed by histopathological examination. Furthermore, the levels of interleukin (IL)-13 in BAL fluid, total and OVA specific immunoglobulins (Ig)-E in serum, were significantly reduced as compared to the OVA group. In addition, sitagliptin significantly increased superoxidase dismutase (SOD) and reduced glutathione (GSH) activities with significant decrease in malondialdehyde (MDA) content in the lung. Importantly, sitagliptin decreased mRNA expression of the inflammatory cytokines tumor necrosis factor-α (TNF-α) and transforming growth factor-β(1) (TGF-β(1)) in lung tissues as compared to the OVA group. Moreover, nitric oxide content as well as the mRNA expression of inducible nitric oxide synthase (iNOS) was remarkably decreased by sitagliptin treatment. Sitagliptin attenuates the allergic airway inflammation suggesting that sitagliptin may have applications in the treatment of bronchial asthma.     

Tempol and perindopril protect against lipopolysaccharide-induced cognition impairment and amyloidogenesis by modulating brain-derived neurotropic factor,neuroinflammation and oxido-nitrosative stress

We aim to evaluate the protective role of the central angiotensin-converting enzyme (ACE) inhibitor perindopril, compared with the standard reactive oxygen species (ROS) scavenger tempol, against lipopolysaccharide (LPS)-induced cognition impairment and amyloidogenesis in a simulation to Alzheimer’s disease (AD). Mice were allocated into a control group, an LPS control group (0.8 mg/kg, i.p., once), a tempol (100 mg/kg/day, p.o., 7 days) treatment group, and two perindopril (0.5 and 1 mg/kg/day, p.o., 7 days) treatment groups. A behavioral study was conducted to evaluate spatial and nonspatial memory in mice, followed by a biochemical study involving assessment of brain levels of Aβ and BDNF as Alzheimer and neuroplasticity markers; tumor necrosis factor-alpha (TNF-α), nitric oxide end-products (NOx), neuronal nitric oxide synthase (nNOS), and inducible nitric oxide synthase (iNOS) as inflammatory markers; and superoxide dismutase (SOD), malondialdehyde (MDA), glutathione reduced (GSH), and nitrotyrosine (NT) as oxido-nitrosative stress markers. Finally, histopathological examination of cerebral cortex, hippocampus, and cerebellum sections was performed using both routine and special staining. Tempol and perindopril improved spatial and nonspatial memory in mice without affecting locomotor activity; decreased brain Aβ deposition and BDNF depletion; decreased brain TNF-α, NOx, nNOS, iNOS, MDA, and NT levels; and increased brain SOD and GSH contents, parallel to confirmatory histopathological findings. Tempol and perindopril may be promising agents against AD progression via suppression of Aβ deposition and BDNF decline, suppression of TNF-α production, support of brain antioxidant status, and amelioration of oxido-nitrosative stress and NT production.     

Response of alveolar macrophages from inducible nitric oxide synthase knockout or wild-type mice to an in vitro lipopolysaccharide or silica exposure

The role of nitric oxide (NO) in pulmonary disease has been controversial with both antiinflammatory (scavenging radicals and inhibiting NF-êB activation) and proinflammatory (forming highly reactive peroxynitrite and augmenting NF-êB activation by inflammatory agents) actions reported. Therefore, a study has been initiated to determine whether deletion of the inducible nitric oxide synthase (iNOS) gene in the C57BL/6J mouse alters the pulmonary macrophage response to lipopolysaccharide (LPS) or silica. The objective of the initial phase of this study was to determine the difference in responsiveness of alveolar macrophages (AMs), harvested from naive wild-type (WT) or iNOS knockout (iNOS KO) mice, to an in vitro LPS or silica exposure. Primary AMs were obtained by bronchoalveolar lavage (BAL) from age- and weight-matched iNOS KO and WT mice. The cells were treated with interferon-gamma (IFN-?) (50 U/ml), IFN-? (50 U/ml) + LPS (1 microg/ml), LPS (0.01-100 microg/ml), or silica (25-250 microg/ml). The following parameters were measured: nitrate and nitrite (NOx), tumor necrosis factor-á (TNF-á), macrophage inflammatory protein-2 (MIP-2), intracellular generation of the reactive oxygen species (ROS) hydrogen peroxide (H(2)O(2) and superoxide (O(*-2)), and basal (unstimulated) total antioxidant capacity. Data show a significant increase in NOx production upon exposure to IFN-? +/- LPS in the WT but not iNOS KO AMs. NOx production by iNOS KO or WT AMs was not altered by in vitro exposure to LPS or silica alone. LPS, but not silica, induced TNF-á and MIP-2 production in both iNOS KO and WT AMs. Statistical analysis of concentration response curves found a significant tendency for greater mediator production in the iNOS KO versus WT AMs. Basal intracellular production of H(2)O(2) and O(*- 2) was significantly greater in the iNOS KO compared to WT AMs. In contrast, LPS- (10 microg/ml) or silica- (100 microg/ml) stimulated intracellular oxidant production was lower in iNOS KO AMs, but overall (basal + stimulated) inflammatory capacity was similar between the cell types. The basal total antioxidant production of the iNOS KO AMs was approximately twofold higher than the WT AMs. In conclusion, certain compensatory changes appear to occur in AMs from iNOS KO mice. In response to the inability to induce NO production, iNOS KO AMs exhibit significantly higher basal generation of H(2)O(2) and (O(*- 2)) as well as higher total antioxidant levels. In addition, LPS induced TNF-á and MIP-2 production tend to be higher in AMs from iNOS KO mice. Such compensatory changes in the AM response may affect the response of iNOS KO mice to inflammatory exposures.     

Protective effects of endothelin-A receptor antagonist BQ123 against LPS-induced oxidative stress in lungs

The aim of this study was to assess whether endothelin-A receptor (ET(A)-R) blocker, BQ123, influences lung edema, lipid peroxidation TBARS), hydrogen peroxide (H(2)O(2)), TNF-α concentration or the glutathione redox system in the lung homogenates obtained from LPS-induced endotoxic shock rats. The study was performed on male Wistar rats (n = 6 per group) divided into groups: (1) saline, (2) LPS (15 mg/kg)-saline, (3) BQ123 (0.5 mg/kg)-LPS, (4) BQ123 (1 mg/kg)-LPS. The ET(A)-R antagonist was injected intravenously 30 min before LPS administration. Five hours after saline or LPS administration, animals were sacrificed and lungs were isolated for indices of lung edema, oxidative stress and TNF-α concentration. Injection of LPS alone resulted in lung edema development and a marked increase in TNF-α (p < 0.02), TBARS (p < 0.02), and H(2)O(2) (p < 0.01) concentrations as well as a depletion of total glutathione (p < 0.01). Administration of BQ123 (1 mg/kg), before LPS challenge, led to a significant reduction in TNF-α and H(2)O(2) concentrations (p < 0.05) and elevation of both total glutathione and the GSH/GSSG ratio (p < 0.05). However, it did not prevent LPS-induced TBARS increase and lung edema formation. Interestingly, a lower dose of BQ123 was much more effective in decreasing H(2)O(2), TBARS, as well as TNF-α levels (p < 0.02, p < 0.05, p < 0.05, respectively). That dose was also effective in prevention of lung edema development (p < 0.01). Taken together, the obtained results indicate that BQ123 is highly effective in decreasing LPS-induced oxidative stress in lungs. Moreover, the dose of 0.5 mg/kg of the antagonist showed to be more effective in decreasing free radical generation and lung edema in endotoxemic rats.     

Effect of anthocyanins contained in a blackberry extract on the circulatory failure and multiple organ dysfunction caused by endotoxin in the rat

Anthocyanins are a group of naturally occurring phenolic compounds related to the colouring of plants, flowers and fruits. These pigments are important as quality indicators, chemotaxonomic markers and for their antioxidant activities. Here we have investigated the therapeutic efficacy of anthocyanins contained in a blackberry extract on (i) circulatory failure, (ii), multiple organ dysfunction and (iii) activity of the inducible isoforms of nitric oxide (NO) synthase (iNOS) and cyclooxygenase (COX-2) in anaesthetised rats with endotoxic shock. In a model of endotoxic shock induced by lipopolysaccharide (LPS, E. coli, 10 mg/kg, i.v.) in the rat, pretreatment with anthocyanins present in the blackberry extract (5 mg/kg, i. v. 30 min before LPS) prevented the hypotension induced by LPS. Endotoxaemia also caused rises in the serum levels of (i) glutamyl oxaloacetic transaminase (GOT), glutamyl pyruvic transaminase (GPT), alkaline phosphates and bilirubin (hepatic dysfunction) (ii) creatinine (renal dysfunction), (iii) amylase and lipase (pancreatic injury), (iii) NOx and 6-keto-PGF1 alpha. Anthocyanins attenuated the hepatic and pancreatic injury, the renal dysfunction and decreased NOx and 6-keto-PGF1 alpha levels. Endotoxaemia for 6 h resulted in a substantial increase in iNOS and COX activity in rat lung, which was attenuated in rats pretreated with anthocyanins. Moreover, anthocyanins (0.02 - 0.32 mg/mL) inhibited in vitro iNOS and COX activity from lung of LPS-treated rats. Polymorphonuclear (PMN) infiltration (myeloperoxidase activity), lipid peroxidation (malondialdehyde levels), as well as tissue injury (histological examination) induced by LPS in rat lung and ileum was reduced by anthocyanins (5 mg/kg, i. v. 30 min before LPS). Furthermore, endotoxaemia induced the formation of nitrotyrosine and poly(ADP-ribose) synthetase (PARS) activation as determined by immunohistochemical analysis of lung and ileum tissues. The degree of staining was lowered by anthocyanin treatment. These results indicate that the anthocyanins contained in the blackberry extract exert multiple protective effects in endotoxic shock.     

Comparative evaluation of anti-inflammatory properties of thymoquinone and curcumin using an asthmatic murine model

This study was designed to compare the inhibitory effects of thymoquinone (TQ) and curcumin (CMN) on the biological changes associating asthma. TQ appeared to exhibit greater inhibitory effects on the aggregation of inflammatory cells in bronchoalveolar lavage (BAL) fluid and in lung tissues. We also measured the effects of the two agents on serum IgE and the changes in the mRNA levels of inducible nitric oxide synthase (iNOS), tumor necrosis factor-α (TNF-α) and transforming growth factor-β1 (TGF-β1). Serum IgE was significantly decreased by TQ and CMN with TQ being more potent. Also, TQ showed superior inhibitory effects on iNOS and TGF-β1. Meanwhile, CMN was more potent in inhibiting mRNA expression of TNF-α. These results suggest that TQ is more potent in inhibiting the inflammatory changes associating asthma. On the other hand, CMN was a less potent inhibitor of all measured parameters, despite its superior inhibitory effect on TNF-α mRNA levels.     

Comparative evaluation of anti-inflammatory properties of thymoquinone and curcumin using an asthmatic murine model

This study was designed to compare the inhibitory effects of thymoquinone (TQ) and curcumin (CMN) on the biological changes associating asthma. TQ appeared to exhibit greater inhibitory effects on the aggregation of inflammatory cells in bronchoalveolar lavage (BAL) fluid and in lung tissues. We also measured the effects of the two agents on serum IgE and the changes in the mRNA levels of inducible nitric oxide synthase (iNOS), tumor necrosis factor-α (TNF-α) and transforming growth factor-β1 (TGF-β1). Serum IgE was significantly decreased by TQ and CMN with TQ being more potent. Also, TQ showed superior inhibitory effects on iNOS and TGF-β1. Meanwhile, CMN was more potent in inhibiting mRNA expression of TNF-α. These results suggest that TQ is more potent in inhibiting the inflammatory changes associating asthma. On the other hand, CMN was a less potent inhibitor of all measured parameters, despite its superior inhibitory effect on TNF-α mRNA levels.     

An insight into the possible protective effect of pyrrolidine dithiocarbamate against lipopolysaccharide-induced oxidative stress and acute hepatic injury in rats

Lipopolysaccharide (LPS) is a major cell wall molecule of Gram-negative bacteria known to stimulate the synthesis and secretion of several toxic metabolites, such as reactive oxygen species. In this study, the effect of pyrrolidine dithiocarbamate (PDTC), an antioxidant with nuclear factor-κB inhibitor activity, was evaluated in LPS-induced oxidative stress and acute hepatic injury in rats. Animals were pretreated for 3 consecutive days with PDTC (200 mg/kg/day, i.p.) or saline and animals were then challenged with LPS (6 mg/kg, i.p.) or saline. Six hours after LPS injection, animals were decapitated and blood and liver samples were collected to assess the chosen biochemical parameters. Saline-pretreated animals challenged with LPS revealed extensive liver damage, as evidenced by increases in serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma glutamyl transferase (γ-GT). Also, LPS treatment resulted in significant increases in serum lactate dehydrogenase (LDH), tumor necrosis factor-alpha (TNF-α) and nitrite levels. Furthermore, LPS challenge caused oxidative stress as indicated by an increase in hepatic lipid peroxidation measured as thiobarbituric acid reactive substances (TBARS) and a decrease in hepatic reduced glutathione concentration (GSH) as well as decreased activities of superoxide dismutase (SOD) and catalase in hepatic tissues. The administration of PDTC prior to LPS challenge resulted in improved liver functions as evidenced by the decline in serum AST, ALT, γ-GT levels and reduction in serum LDH, TNF-α and nitrite levels. Moreover, PDTC reduced the chosen lipid peroxidation marker, TBARS and increased GSH concentration, and SOD and catalase activities in hepatic tissues. These results indicate that PDTC may be a useful pharmacological agent in alleviating LPS-induced oxidative stress and acute hepatic injury.     

Escin attenuates acute lung injury induced by endotoxin in mice

Endotoxin causes multiple organ dysfunctions, including acute lung injury (ALI). The current therapeutic strategies for endotoxemia are designed to neutralize one or more of the inflammatory mediators. Accumulating experimental evidence suggests that escin exerts anti-inflammatory and antiedematous effects. The aim of this study was to evaluate the effect of escin on ALI induced by endotoxin in mice. ALI was induced by injection of lipopolysaccharide (LPS) intravenously. The mice were given dexamethasone or escin before injection of LPS. The mortality rate was recorded. Tumor necrosis factor-α (TNF-α), interleukin 1β (IL-1β) and nitric oxide (NO) were measured. Pulmonary superoxide dismutase (SOD), glutathione peroxidase (GPx) activity, glutathione (GSH), malondialdehyde (MDA) contents, and myeloperoxidase (MPO) activity were also determined. The expression of glucocorticoid receptor (GR) level was detected by Western blotting. Pretreatment with escin could decrease the mortality rate, attenuate lung injury resulted from LPS, down-regulate the level of the inflammation mediators, including NO, TNF-α, and IL-1β, enhance the endogenous antioxidant capacity, and up-regulating the GR expression in lung. The results suggest that escin may have potent protective effect on the LPS-induced ALI by inhibiting of the inflammatory response, and its mechanism involves in up-regulating the GR and enhancing the endogenous antioxidant capacity.     

谷氨酰胺对内毒素诱导大鼠肺组织氧化应激反应的影响

目的探讨谷氨酰胺对内毒素(LPS)诱导大鼠肺组织氧化应激反应的影响。方法雄性SD大鼠50只,随机分为5组(n=10):对照组(A组);LPS组(B组),股静脉注射LPS 5 mg/kg;C、D、E组为谷氨酰胺+LPS组,分别于LPS注入前1 h时,LPS注入同时,LPS注入后1 h时,均静脉注射谷氨酰胺0.75 g/kg。于注射LPS后4 h时处死大鼠,测定肺组织超氧化物歧化酶(SOD)活性、丙二醛(MDA)、一氧化氮(NO)、总一氧化氮合酶(tNOS)水平,诱导型一氧化氮合酶(iNOS)活性及iNOS mRNA表达。结果与A组比较,B组肺组织SOD活性下降,MDA、NO、tNOS水平、iNOS活性及iNOS mRNA表达均升高(P<0.05及P<0.01);与B组比较,C、D组肺组织SOD活性升高,MDA、NO、tNOS水平、iNOS活性及iNOS mRNA表达降低(P<0.05及P<0.01),E组上述各项指标比较差异无统计学意义(P>0.05)。结论谷氨酰胺早期给药可减轻LPS诱导肺组织氧化应激反应。     

Role of inducible nitric oxide synthase-derived nitric oxide in silica-induced pulmonary inflammation and fibrosis

Inhalation of crystalline silica can produce lung inflammation and fibrosis. Inducible nitric oxide synthase (iNOS)-derived nitric oxide (NO) is believed to be involved in silica-induced lung disease. To investigate the role of iNOS-derived NO in this disease, the responses of iNOS knockout (KO) versus C57Bl/6J wild-type (WT) mice to silica were compared. Male mice (8-10 wk old, mean body weight 24.0 g) were anesthetized and exposed, by aspiration, to silica (40 mg/kg) or saline. At 24 h and 42 d postexposure, lungs were lavaged with saline. The first bronchoalveolar lavage (BAL) fluid supernatant was analyzed for lactate dehydrogenase (LDH) activity, levels of albumin, tumor necrosis factor-alpha (TNF-alpha), and macrophage inflammatory protein-2 (MIP-2), as well as total antioxidant capacity (TAC). The cellular fraction of the total BAL was used to determine alveolar macrophage (AM) and polymorphonuclear leukocyte (PMN) counts, and zymosanstimulated AM chemiluminescence (AM-CL). In separate mice, lung histopathological changes were evaluated 42 d postexposure. Acute (24-h) silica exposure decreased AMs, increased PMNs, increased LDH activity and levels of albumin, TNF-alpha, and MIP-2 in BAL fluid, and enhanced AM-CL in both iNOS KO and WT mice. However, iNOS KO mice exhibited less AM activation (defined as increased AM-CL and decreased AM yield) than WT. Furthermore, TAC following acute silica decreased in WT but was maintained in iNOS KO mice. Pulmonary reactions to subchronic (42 d) silica exposure were similar to acute. However, histopathological and BAL fluid indices of lung damage and inflammation, AM activation, and lung hydroxyproline levels were significantly less in iNOS KO compared to WT mice. These results suggest that iNOS-derived NO contributes to the pathogenesis of silica-induced lung disease in this mouse model.     

Niacinamide abrogates the organ dysfunction and acute lung injury caused by endotoxin

Poly (ADP-ribose) synthabse (PARS) or polymerase (PARP) is a cytotoxic enzyme causing cellular damage. Niacinamide inhibits PARS or PARP. The present experiment tests the effects of niacinamide (NCA) on organ dysfunction and acute lung injury (ALI) following lipopolysaccharide (LPS). LPS was administered to anesthetized rats and to isolated rat lungs. In anesthetized rats, LPS caused systemic hypotension and increased biochemical factors, nitrate/nitrite (NOx), methyl guanidine (MG), tumor necrosis factoralpha (TNFalpha), and interleukin-1beta (IL-1beta). In isolated lungs, LPS increased lung weight (LW) to body weight ratio, LW gain, protein and dye tracer leakage, and capillary permeability. The insult also increased NOx, MG, TNFalpha, and IL-1beta in lung perfusate, while decreased adenosine triphosphate (ATP) content with an increase in PARP activity in lung tissue. Pathological examination revealed pulmonary edema with inflammatory cell infiltration. These changes were abrogated by posttreatment (30 min after LPS) with NCA. Following LPS, the inducible NO synthase (iNOS) mRNA expression was increased. NCA reduced the iNOS expression. Niacinamide exerts protective effects on the organ dysfunction and ALI caused by endotoxin. The mechanisms may be mediated through the inhibition on the PARP activity, iNOS expression and the subsequent suppression of NO, free radicals, and proinflammatory cytokines with restoration of ATP.     

Beneficial effect of hyperbaric oxygen pretreatment on lipopolysaccharide-induced shock in rats

1. We investigated the effect of hyperbaric oxygenation (HBO2) pretreatment on the production of exhaled nitric oxide (ENO) and the expression of lung inducible nitric oxide synthase (iNOS) by Escherichia coli lipopolysaccharide (LPS)-induced shock in an experimental rat model. 2. Rats were randomized into four groups, anaesthetized, mechanically ventilated with room air and infused with normal saline (2 mL/h) through the jugular vein for 5 h. Group 1 (NS) received only normal saline. Group 2 (HBO2-NS) was pretreated with HBO2 at 2.8 absolute atmospheres for 2 h and then received normal saline. Group 3 (LPS) received LPS, 20 mg/kg, i.v., bolus. Group 4 (HBO2-LPS) was pretreated with HBO2 for 2 h, followed by LPS. 3. Arterial blood gases, blood pressure, blood pH and ENO production were measured every 30 min. Plasma nitrite/nitrate (NOx) concentrations were assessed at the beginning (baseline) and at the end of the study. Lung myeloperoxidase (MPO) activity, iNOS expression and histological scores were measured for the evaluation of lung injury. 4. Administration of LPS was associated with decreased blood pressure and pH, increased ENO production, plasma NOx concentrations, lung iNOS expression and MPO activity. 5. Pretreatment with HBO2 significantly alleviated the LPS-induced hypotension, acidosis and decreased ENO production, plasma NOx concentrations, lung MPO activity and expression of iNOS. Hyperbaric O2 had no effect on control rats. 6. Our data show that HBO2 pretreatment has beneficial haemodynamic effects in rats with endotoxin shock. The beneficial effects of HBO2 may be partially mediated by decreased ENO production via reduced LPS-induced lung iNOS expression.     

Melatonin alleviates lung damage induced by the chemical warfare agent nitrogen mustard

The cytotoxic mechanism of mustards has not been fully elucidated; recently, we reported that reactive oxygen species, nitric oxide [produced by inducible nitric oxide synthase (iNOS)] and peroxynitrite are involved in the pathogenesis and responsible for mustard-induced toxicity. Melatonin, a potent antioxidant molecule, acts as an iNOS inhibitor and a peroxynitrite scavenger. Using the prototypic nitrogen mustard (mechlorethamine/HN2) as a model and based on its known cytotoxic mechanisms, the present study was performed to test melatonin for its capability in protecting the lungs of injured male Wistar rats. Lung mustard toxicity was induced via an intratracheally injection of HN2 (0.5mg/kg) dissolved in saline (100microl). Control animals were injected the same amount of saline only. Melatonin was administered intraperitoneally with two different doses (20mg/kg or 40mg/kg) beginning 1h before HN2 application and continued every 12h for six replications. Forty-eight hours after the last melatonin injection, the animals were sacrificed and their lungs were taken for further assay, i.e., malondialdehyde (MDA) levels, and superoxide dismutase (SOD), glutathione peroxidase (GPx) and iNOS activity. Additionally their urine was collected for nitrite-nitrate (NO(x)) analysis. HN2 injection caused increased iNOS activity and MDA levels in lung tissue and NO(x) values in urine; lung GPx activity was significantly depressed. Melatonin restored all of these oxidative and nitrosative stress markers in a dose-dependent manner. In conclusion, the results of study provide evidence that melatonin may have the ability to reduce mustard-induced toxicity in the lungs.     

Curcumin inhibits lipopolysaccharide (LPS)-induced endotoxemia and airway inflammation through modulation of sequential release of inflammatory mediators (TNF-α and TGF-β1) in murine model

Objective

Curcumin (diferuloylmethane), a major component of turmeric is well known for its anti-inflammatory potential. Present study investigates sequential release of inflammatory mediators post LPS challenge (10 mg/kg,i.p.) causing lung inflammation and its modulation by curcumin through different routes (20 mg/kg, i.p and 10 mg/kg, i.n.) in murine model. Dexamethasone (1 mg/kg, i.p) was used as standard drug.

Methods

Lung Inflammation was evaluated by histopathological analysis, myeloperoxidase (MPO) activity followed by inflammatory cell count and total protein content measurements in bronchoalveolar fluid (BALF). Reactive oxygen species (ROS), nitrite and TNF-α levels were measured as markers of endotoxin shock at different time points (1–72 h). The mRNA expression of transforming growth factors-β1 (TGF-β1), iNOS and Toll-like receptor-4 (TLR-4) were measured followed by Masson’s trichrome staining and hydroxyproline levels as collagen deposition marker leading to fibrotic changes in lungs.

Results

We found that LPS-induced lung inflammation and injury was maximum 24-h post LPS challenge shown by MPO and histological analysis which was further supported by elevated nitrite and ROS levels whereas TNF-α level was highest after 1 h. Endotoxin-induced mortality was significantly reduced in curcumin (i.p) pretreatment groups up to 72-h post LPS challenge. Significant inhibition in mRNA expression of iNOS, TGF-β1 and TNF-α level was noted after curcumin treatment along with lowered MPO activity, inflammatory cell count, ROS, nitrite levels and collagen deposition in lungs.

Conclusion

Our results suggest that higher endotoxin dose causes inflammatory mediator release in chronological order which tend to increase with time and reached maximum after 24-h post-endotoxin (LPS) exposure. Intraperitoneal route of curcumin administration was better in modulating inflammatory mediator release in early phase as compared to intranasal route of administration. It can be used as supplementary therapeutic intervention at early stage of endotoxemia, having fewer side effects.

     

Inhibitory effects of honokiol on lipopolysaccharide-induced cellular responses and signaling events in human renal mesangial cells

Honokiol has been shown to possess a lot of pharmacologic benefits, including antioxidative, antiangiogenic and antineoplastic effects. In the present study, we investigated the anti-inflammatory effects of honokiol and the signaling mechanisms involved in lipopolysaccharide (LPS)-induced conditions in human renal mesangial cells (HRMCs). Honokiol did not significantly change HRMC viability when used at a concentration of < 20 μmol/l but markedly altered cell viability at concentrations of > 40 μmol/l. In this study, LPS treatment led to a marked upregulation of the levels of IL-1β, IL-18, TNF-α, TGF-β1, CCL2, CCL3, and CCL5 in HRMCs. The expression of COX-2, iNOS, and their products PGE₂ and NO also increased. The upregulation of these molecules was significantly abolished by honokiol in a dose-dependent manner. Moreover, honokiol almost completely reversed IL-1β, CCL3, and NO expression at 10 μmol/l, and IL-18, TNF-α, TGF-β1, and COX-2 expression at 20 μmol/l. In addition, phospho-NF-κB p65 at Ser536, phospho-Akt, and phospho-p42/44 were dramatically suppressed by honokiol in LPS-treated HRMCs. These results indicate that honokiol can inhibit the LPS-induced expression of inflammatory cytokines and mediators in HRMCs. The anti-inflammatory mechanisms of honokiol are partly due to the suppression of the phospho-NF-κB p65, phospho-Akt and phospho-p42/44 pathways.     

大鼠心肌缺血再灌注诱发肺部炎性纤维化

目的探讨大鼠心肌缺血再灌注损伤是否会诱发肺部炎症以及纤维化。方法 Wistar大鼠16只,随机分为假手术组(S组)、心肌缺血再灌注组(IR组),2组均缺血45 min再灌注3 h。实验结束后放血处死大鼠,取肺组织、支气管肺泡灌洗液和血清,测定血清肌酸激酶同工酶(CK-MB)浓度、蛋白含量以及转化生长因子(TGF)-β1浓度,计算肺通透性指数(PPI)、测定肺组织肿瘤坏死因子(TNF)-α蛋白的表达。结果与假手术组比较,心肌缺血再灌注组血清CK-MB活性及TGF-β1浓度均增高,PPI值升高,肺组织TNF-α蛋白表达上调,差异有统计学意义。结论大鼠心肌缺血再灌注可诱发肺部炎性纤维化。