首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
2.
The acute respiratory distress syndrome (ARDS) is a severe form of acute lung injury (ALI). Its pathogenesis is closely linked with reactive oxygen species (ROS). Antioxidation has been considered as an efficient treatment. Besides, liposomes are widely investigated as potential drug carriers due to their ability to protect and carry drug molecules to the target organ such as the lung. The present study was undertaken to investigate whether dipyridamole (DIP), delivered as a liposomal preparation, can ameliorate the lipopolysaccharides (LPS)-induced ALI due to the changes of its biodistribution. First, the liposomes entrapping DIP were prepared by film hydration for treating ARDS. Subsequently, the characterizations including entrapment efficiency, size, span and micrograph of DIP liposomes were measured. The concentration change of DIP in tissues and plasma of mice after intravenous administration of DIP injection and DIP liposomes was determined by RP-HPLC and calculated to lung targeting parameters. To prove the therapeutic efficiency, the effects of DIP liposomes on LPS-induced ALI were studied compared with DIP injection. The results showed DIP liposomes have the relative high entrapment efficiency and satisfying particle size. Compared with DIP injection, the liposomes increased the accumulation of DIP in the lung on a vast scale. Furthermore, DIP liposomes alleviated the ALI induced by LPS significantly. All of the results suggested that DIP liposomes have the potential efficacy in treating ALI/ARDS due to their obvious lung targeting.  相似文献   

3.
The acute respiratory distress syndrome (ARDS) is a severe form of acute lung injury (ALI). Its pathogenesis is closely linked with reactive oxygen species (ROS). Antioxidation has been considered as an efficient treatment. Besides, liposomes are widely investigated as potential drug carriers due to their ability to protect and carry drug molecules to the target organ such as the lung. The present study was undertaken to investigate whether dipyridamole (DIP), delivered as a liposomal preparation, can ameliorate the lipopolysaccharides (LPS)-induced ALI due to the changes of its biodistribution. First, the liposomes entrapping DIP were prepared by film hydration for treating ARDS. Subsequently, the characterizations including entrapment efficiency, size, span and micrograph of DIP liposomes were measured. The concentration change of DIP in tissues and plasma of mice after intravenous administration of DIP injection and DIP liposomes was determined by RP-HPLC and calculated to lung targeting parameters. To prove the therapeutic efficiency, the effects of DIP liposomes on LPS-induced ALI were studied compared with DIP injection. The results showed DIP liposomes have the relative high entrapment efficiency and satisfying particle size. Compared with DIP injection, the liposomes increased the accumulation of DIP in the lung on a vast scale. Furthermore, DIP liposomes alleviated the ALI induced by LPS significantly. All of the results suggested that DIP liposomes have the potential efficacy in treating ALI/ARDS due to their obvious lung targeting.  相似文献   

4.
Wang H  Xu DX  Lu JW  Zhao L  Zhang C  Wei W 《Acta pharmacologica Sinica》2007,28(11):1803-1809
Aim: To investigate the effects of N-acetylcysteine on D-galactosamine (GAIN)/ lipopolysaccharide (LPS)-induced apoptotic liver injury in mice. Methods: When given together with a low dose of LPS, GaIN highly sensitizes animals to produce apoptotic liver injury with severe hepatic congestion, resulting in rapid death. In the GalN/LPS model, TNF-α is the major mediator leading to apoptotic liver injury. Reactive oxygen species (ROS) are involved in GaiN-induced sensitization to TNF-α-evoked hepatocyte apoptosis. N-acetylcysteine (NAC) is an antioxidant and a glutathione (GSH) precursor. In this study, we investigated the effects of NAC on LPS-induced apoptotic liver injury in GaiN-sensitized mice. Results: Pretreatment with NAC significantly reduced GalN/LPS-induced elevation of serum alanine aminotransferase levels. In parallel, GalN/LPS-induced hepatic necrosis and congestion were obviously improved by NAC. Furthermore, NAC pretreatment significantly alleviated GalN/LPS-induced hepatic apoptosis, measured by the inhibition of hepatic caspase-3 activity and attenuation of DNA laddering. NAC pretreatment had no effect on LPS-evoked nitric oxide production in GaiN-sensitized mice. Increases in serum TNF-α concentration, which were observed in GalN/LPS-treated mice, were not significantly reduced by NAC. Although NAC pretreatment significantly alleviated LPS-induced hepatic GSH depletion, DL-buthionine-(SR)-sulfoximine, an inhibitor of GSH synthesis, did not influence the protective effect of NAC on GalN/LPS-induced apoptotic liver injury. Conclusion: NAC attenuates GalN/LPS-induced apoptotic liver injury via its strong ROS scavenging and anti-apoptotic effects.  相似文献   

5.
6.
Lipopolysaccharide (LPS), a component of the cell wall of Gram-negative bacteria, stimulates phagocytes to generate metabolites that play an important role in the pathogenesis of acute lung injury. In this study, the prophylactic effect of liposome-entrapped dexamethasone (L-DEX) was evaluated in an animal acute lung injury model. Rats were pretreated intratracheally with L-DEX or dexamethasone phosphate (DEX) at a dose of 800 microg dexamethasone/kg body weight; 1 hr later, pretreated animals were challenged i.v. with LPS (Escherichia coli 0111:B4, 1 mg/kg body weight) and killed 24 hr later. Challenge of saline-pretreated animals with LPS resulted in lung injury, as evidenced by increases in wet lung weight and decreases in lung angiotensin-converting enzyme and alkaline phosphatase activities, injury markers of pulmonary capillary endothelial and alveolar type II epithelial cells, respectively. Also, LPS injection resulted in significant increases in plasma phospholipase A(2), thromboxane B(2), and leukotriene B(4) concentrations. The LPS challenge also increased pulmonary myeloperoxidase and elastase activities as well as chloramine concentrations, suggestive of neutrophil infiltration and activation of the inflammatory response. Pretreatment of animals with L-DEX was significantly more effective than pretreatment with the free drug in reducing lung inflammation and other lung injuries, as indicated by the appropriate injury markers used in this study. Our results suggested that the pulmonary delivery of liposome-entrapped anti-inflammatory drugs such as dexamethasone improves prophylactic efficacy in counteracting LPS-induced lung injury.  相似文献   

7.
Acute lung injury (ALI) is a complex clinical syndrome with high morbidity and mortality rates. Autophagy is an adaptive process that plays a complex role in ALI. The aim of this study was to investigate the effects of autophagy on lipopolysaccharide (LPS)-induced lung injury by establishing a rat ALI model and to further explore the possible mechanisms involved. Rats were pretreated with the autophagy inhibitor 3-methyladenine (3-MA) or the autophagy activator rapamycin before they were challenged with the intratracheal instillation of LPS (5 mg/kg). The level of autophagy in the lung tissue was detected. Lung injury and vascular permeability were assessed. The role of the mechanistic target of rapamycin (mTOR)-mediated Unc-51-like kinase 1 (ULK1) and the class III PI3 kinase VPS34 in autophagy regulation was examined. LPS challenge induced autophagy and rapamycin pretreatment enhanced autophagy activity in LPS-induced ALI rats. LPS caused severe lung injury and high pulmonary vascular permeability, which could be alleviated by enhancing autophagy. In addition, the inhibition of mTOR upregulated the expression of ULK1 and VPS34 and thus increased LPS-induced autophagy. Autophagy plays a protective role in LPS-induced ALI, and enhancing autophagy via the inhibition of mTOR alleviates lung injury and pulmonary barrier function. Moreover, mTOR negatively mediates ULK1 and VPS34 to regulate LPS-induced autophagy in rats.  相似文献   

8.
N-acetylcysteine abrogates acute lung injury induced by endotoxin   总被引:5,自引:0,他引:5  
1. Acute lung injury (ALI) or acute respiratory distress syndrome is a serious clinical problem with high mortality. N-Acetylcysteine (NAC) is an anti-oxidant and a free radical scavenger. It has been reported recently that NAC ameliorates organ damage induced by endotoxin (lipopolysaccharide; LPS) in conscious rats. The present study was designed to evaluate the effects of NAC on LPS-induced ALI and other changes in anaesthetized rats. 2. Sprague-Dawley rats were anaesthetized with pentobarbital (40 mg/kg, i.p.). Endotracheal intubation was performed to provide artificial ventilation. Arterial pressure and heart rate were monitored. The extent of ALI was evaluated with the lung weight (LW)/bodyweight ratio, LW gain, exhaled nitric oxide (NO) and protein concentration in bronchoalveolar lavage (PCBAL). Haematocrit, white blood cells, plasma nitrate/nitrite, methyl guanidine (MG), tumour necrosis factor (TNF)-alpha and interleukin (IL)-1b were measured. Pathological changes in the lung were examined and evaluated. 3. Endotoxaemia was produced by injection of 10 mg/kg, i.v., LPS (Escherichia coli). Animals were randomly divided into three groups. In the vehicle group, rats received an i.v. drip of physiological saline solution (PSS) at a rate of 0.3 mL/h. The LPS group received an i.v. drip of PSS for 1 h, followed by LPS (10 mg/kg by slow blous injection, i.v., over 1-2 min). Rats in the LPS + NAC group received NAC by i.v. drip at a rate of 150 mg/kg per h (0.3 mL/h) for 60 min starting 10 min before LPS administration (10 mg/kg by slow blous injection, i.v., over 1-2 min). Each group was observed for a period of 6 h. 4. N-Acetylcysteine treatment improved the LPS-induced hypotension and leukocytopenia. It also reduced the extent of ALI, as evidenced by reductions in LW changes, exhaled NO, PCBAL and lung pathology. In addition, NAC diminished the LPS-induced increases in nitrate/nitrite, MG, TNF-a and IL-1b. 5. In another series of experiments, LPS increased the mortality rate compared with the vehicle group (i.v. drip of PSS at a rate of 0.3 mL/h) during a 6 h observation period. N-Acetylcysteine, given 10 min prior to LPS, significantly increased the survival rate. 6. The results of the present study suggest that NAC exerts a protective effect on the LPS-induced ALI. The mechanisms of action may be mediated through the reduction of the production of NO, free radicals and pro-inflammatory cytokines.  相似文献   

9.
The activation of NLRP3 inflammasome and NF-κB pathway, associating with oxidative stress, have been implicated in the development of acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). NecroX-5 has been reported to exhibit the effects of anti-oxidation and anti-stress in various diseases. However, the role of NecroX-5 in ALI has not been explicitly demonstrated. The aim of this study was to explore the therapeutic effects and potential mechanism action of NecroX-5 on ALI. Here, we found that NecroX-5 pretreatment dramatically diminished the levels of IL-1β, IL-18 and ROS in in RAW264.7 cells challenged with LPS and ATP. Furthermore, NecroX-5 suppressed the activation of NLRP3 inflammasome and NF-κB signal pathway. In addition, NecroX-5 also inhibited the thioredoxin-interacting protein (TXNIP) expression. In vivo, NecroX-5 reduced the LPS-induced lung histopathological injury, the number of TUNEL-positive cells, lung wet/dry (W/D) ratio, levels of total protein and inflammatory cytokines in the bronchoalveolar lavage fluid (BALF) in mice. Additionally, LPS-induced upregulation of myeloperoxidase (MPO), ROS production and malondialdehyde (MDA) were inhibited by NecroX-5 administration. Thus, our results demonstrate that NecroX-5 protects against LPS-induced ALI by inhibiting TXNIP/NLRP3 and NF-κB.  相似文献   

10.
顾红军  孙沁莹  李强 《中国药房》2006,17(22):1702-1704
目的研究代谢性抗氧化剂硫辛酸(LA)对急性肺损伤/急性呼吸窘迫综合征(ALI/ARDS)模型大鼠的保护作用,为ALI/ARDS药物治疗提供新的途径。方法将ALI/ARDS大鼠分为正常对照组(生理盐水(NS)组)、ALI/ARDS模型组(脂多糖(LPS)组)、LA干预组(LA组)和谷胱甘肽干预组(GSH组),LPS注射30min后分别尾静脉注射LA和GSH。并于注射LPS和NS1、2、4、6h后动态观察血清α-干扰素(TNF-α)水平,6h处死大鼠,观察光镜和电镜下肺组织的病理改变,测定动脉血氧分压(PaO2)、血清脂过氧化物(LPO)水平、肺湿干比(W/D)、肺泡灌洗液(BALF)中蛋白浓度和TNF-α水平。结果LA组光镜和电镜下病理表现较LPS组均有好转;与LPS组比较,LA组和GSH组PaO2水平明显升高(P<0·01),LPO、W/D、BALF中蛋白浓度明显下降(P<0·01);LA和GSH能明显抑制BALF中TNF-α水平;血清中TNF-α水平进行性下降,第1、4、6h时有统计学意义(P<0·01)。结论LA对LPS诱发大鼠ALI/ARDS有保护作用。  相似文献   

11.
Ginsenoside Rg3 (GRg3), one of the major active saponins isolated from ginseng (the root of Panax ginseng C.A. Meyer, Araliaceae), has been reported with many health benefits. Currently, the protective effect of GRg3 on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice was investigated. The results indicated that GRg3 treatment could greatly attenuate LPS-induced histopathological alterations in the lung in a concentration-dependent manner. LPS-induced increase of lung wet-to-dry weight ratio (W/D ratio) was also dose-dependently reduced by GRg3 treatment. LPS-induced increases of the total cells, neutrophils and macrophages in the bronchoalveolar lavage fluids (BALFs) were significantly inhibited by GRg3 treatment in a dose-dependent fashion. The levels of pro-inflammatory cytokines including TNF-α, IL-1β and IL-6 in BALFs increased after LPS-induced ALI, which was inhibited by GRg3. Western blot results showed that during ALI LPS activated NF-κB pathway in the lung tissues by upregulating NF-κB p65 phosphorylation and its downstream COX-2 expression; however, these effects of LPS were inhibited by GRg3 treatment. Taken together, these findings in present study suggested that GRg3 provided protective effects against LPS-induced ALI in animal model and might harbor the potential to be considered as drug for the treatment of ALI in clinic.  相似文献   

12.
The garlic-derived organosulfur compound S-allylmercaptocysteine (SAMC) has been reported to exhibit anti-inflammatory and anti-oxidative activities, whereas its potential therapeutic effect on lipopolysaccharide (LPS)-induced acute lung injury (ALI) is unknown. In this study, we focused on exploring the therapeutic effects of SAMC on LPS-induced ALI mice and the involvement of underlying molecular mechanisms. BalB/c mice were treated with SAMC (10, 30 and 60 mg/kg) or positive control N-acetylcysteine (NAC, 500 mg/kg) by gavage after intratracheal instillation of LPS for 30 min and were sacrificed 24 h after LPS administration. Our results indicate that the treatment with SAMC not only ameliorated the histological changes but also decreased LPS-triggered lung edema. Moreover, SAMC displayed an anti-inflammatory effect through reducing inflammatory cells infiltration, myeloperoxidase (MPO) formation and inhibiting pro-inflammatory cytokines/mediator production including tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX2) via suppressing the activation of nuclear factor-kappaB (NF-κB) signaling pathway. Furthermore, SAMC attenuated oxidative stress evoked by LPS via diminishing malondialdehyde (MDA) formation and reversing glutathione (GSH) and superoxide dismutase (SOD) depletion. Meanwhile, SAMC up-regulated expressions of endogenous antioxidant/detoxifying proteins including heme oxygenase-1 (HO-1) and NAD(P)H: quinone oxidoreductase 1(NQO1) through reversing the suppression of Kelch-like ECH-associated protein 1 (Keap1)/nuclear factor erythroid-2 related factor 2 (Nrf2) signaling pathway. Our results demonstrate that SAMC effectively attenuated LPS-induced ALI which was largely dependent upon inhibition of inflammation and oxidative stress via NF-κB and Keap1/Nrf2 signaling pathways.  相似文献   

13.
目的观察不同浓度的氯胺酮对脂多糖(LPS)诱发的小鼠肺泡巨噬细胞核因子(NF)-κB的活化,进一步探讨氯胺酮对急性肺损伤(ALI)/急性呼吸窘迫综合征(ARDS)的应用前景。方法在小鼠肺泡巨噬细胞(PAM)培养液中加入脂多糖(LPS)10μg/ml得到内毒素肺损伤细胞模型。实验分为LPS刺激组(加LPS10μg/ml)、氯胺酮干预组1(同时加入LPS10μg/ml和氯胺酮10μmol/L)、氯胺酮干预组2(同时加入LPS10μg/ml和氯胺酮100μmol/L)、氯胺酮干预组3(同时加入LPS10μg/ml和氯胺酮1000μmol/L)4组。分别于刺激后0.5,1,4,6h留取细胞,用免疫组织化学染色图像分析法检测细胞核中NF-κB活性。结果①LPS+不同浓度的氯胺酮(10,100,1000μmol/L)后,NF-κBp50活性与LPS组相比在1h和4h处有明显的下降(P<0.05),且有剂量依赖性,氯胺酮浓度越大,NF-κBp50活性下降越明显,各组之间差异有统计学意义(P<0.05)。②NF-κBp65活性的检测与NF-κBp50的检测结果相似。结论氯胺酮通过对PAM内NF-κB活化的抑制,可阻止和延缓LPS诱发的ALI的发生,可能有一定的肺保护作用。  相似文献   

14.
Toll-like receptor-4 (TLR4) signaling has been implicated in innate immunity and acute inflammation following acute lung injury (ALI). As such, modulating inflammatory response through TLR4 represents an attractive therapeutic approach to treat ALI. Increasing evidence demonstrates that hyaluronan (HA) can modulate TLR4 activation and has shown early promise as a therapeutic agent in ALI. However, the mechanism associated with HA has not been fully elucidated. In the current study, we sought to determine the effects of HA on lipopolysaccharide (LPS)-induced inflammatory response and gain insights into the mechanism of action in mice with intratracheal instillation of LPS. Our results demonstrate that in contrast to mice challenged with LPS, pretreatment with HA significantly inhibited inflammatory cell recruitment, attenuated lung injury and suppressed the level of cytokine/chemokine in bronchial alveolar lavage fluid (BALF). Investigation of the mechanism responsible for inhibition of LPS activation showed HA treatment significantly inhibited the nuclear translocation of NF-κB p65 and protein expression of myeloid differentiation primary response protein (MyD88) and TIR-domain-containing adapter-inducing interferon-β (TRIF) and p38 MAPK, JNK and ERK activation in lung tissue. Furthermore, we compared the protection effect of HA in TLR4-deficient mice with those of genetically matched wild type (WT) mice in an acute model of lung injury. However, in TLR4-deficient mice, HA pretreatment before LPS instillation fail to affect the LPS response. Therefore, our findings suggest that HA pretreatment attenuated LPS-induced ALI and the anti-inflammatory function of HA was partial dependent on TLR4, which shed new light on potential elements that regulate the lung injury response.  相似文献   

15.
Recent studies show that mitogen-activated protein kinases (MAPKs) and nuclear factor-kappa B (NF-κB) signaling pathways are two pivotal roles contributing to the development of lipopolysaccharide (LPS)-induced acute lung injury (ALI). The present study aimed to investigate the protective effect of kaempferol (Kae), a naturally occurring flavonoid compound, on ALI and explore its possible mechanisms. Male BALB/c mice with ALI, induced by intranasal instillation of LPS, were treated or not with Kae (100mg/kg, intragastrically) 1h prior to LPS exposure. Kae treatment attenuated pulmonary edema of mice with ALI after LPS challenge, as it markedly decreased the lung W/D ratio of lung samples, protein concentration and the amounts of inflammatory cells in BALF. Similarly, LPS mediated overproduction of proinflammatory cytokines in BALF, including TNF-α, IL-1β and IL-6, was strongly reduced by Kae. Histological studies demonstrated that Kae substantially inhibited LPS-induced alveolar wall thickness, alveolar hemorrhage and leukocytes infiltration in lung tissue with evidence of reduced myeloperoxidase (MPO) activity. Kae also efficiently increased superoxide dismutase (SOD) activity of lung sample when compared with LPS group, which was obviously reduced by LPS administration. In addition, Western blot analysis indicated that the activation of MAPKs and NF-κB signaling pathways stimulated by LPS was significantly blocked by Kae. Taken together, our results suggest that Kae exhibits a protective effect on LPS-induced ALI via suppression of MAPKs and NF-κB signaling pathways, which may involve the inhibition of tissue oxidative injury and pulmonary inflammatory process.  相似文献   

16.
17.
18.
Lipopolysaccharide (LPS) is a major cell wall molecule of Gram-negative bacteria known to stimulate the synthesis and secretion of several metabolites, such as reactive oxygen species, from phagocytes that play an important role in the pathogenesis of tissue injuries. In this study, the prophylactic effect of the antioxidant lipoic acid was evaluated in an animal acute organ injury model. Animals were pre-treated intraperitoneally with lipoic acid (50 mg kg(-1) body weight) or saline; 3 h later, pretreated animals were challenged intravenously with LPS (Escherichia coli 0111:B4, 1.0 mg kg(-1) body weight) or saline and killed 21 h later. Saline-pretreated animals challenged with LPS were extensively damaged in the liver, as evidenced by an increase in plasma alanine and aspartate aminotransferase activities. Also, LPS injection to saline-pretreated animals resulted in significant increases in plasma tumour necrosis factor-alpha (TNFalpha) and nitric oxide (NO) concentrations, suggestive of activation of the proinflammatory response. The LPS challenge to saline-pretreated animals also increased hepatic myeloperoxidase activity as well as protease and chloramine levels, suggestive of neutrophil infiltration and activation of the inflammatory response. In addition, the involvement of oxidative stress was evident, because a significant increase in lipid peroxidation was observed in the livers of saline-pretreated animals challenged with LPS. The administration of lipoic acid prior to LPS challenge resulted in a significant alleviation of liver injuries, evidenced by a general reversal of the altered biochemical indices toward normal among treated animals. These results indicate that lipoic acid may serve as a potentially effective prophylactic pharmacological agent in alleviating LPS-induced tissue injuries.  相似文献   

19.
Micro RNA (miRNA) and mitogen-activated protein kinase (MAPK) are reported as the crucial regulators of inflammatory responses in acute lung injury (ALI). This study will explore the role of the miR-342/MAPK1 axis in regulation of lipopolysaccharide (LPS)-induced ALI. We found that miR-342 was down-regulated in LPS-induced A549 cells compared with the control group with DMSO, accompanied by elevated inflammatory cytokines and apoptosis. Over-expression of miR-342 reduced LPS-induced inflammatory responses and apoptosis in LPS-stimulated A549 cells, and had a protective role in LPS-treated mice with ALI by decreasing levels of inflammatory cytokines, improving survival of mice with ALI, and ameliorating the lung permeability. Dual-luciferase reporter gene assay demonstrated that miR-342 regulated the expression of MAPK1 by directly targeting its 3′ untranslated region (3′-UTR). Mechanistically, MAPK1 silencing abrogated LPS-induced inflammatory injury in A549 cells, and partially enhanced the protective effect of miR-342. Therefore, miR-342 attenuates LPS-induced ALI by targeting MAPK1 expression, thereby protecting against A549 cell injury induced by LPS and lung injury of mice with ALI.  相似文献   

20.
sRAGE对脂多糖介导的小鼠急性肺损伤的保护作用   总被引:1,自引:0,他引:1  
目的探讨可溶性晚期糖基化终末产物受体(sRAGE)对脂多糖(LPS)介导的小鼠急性肺损伤(ALI)的保护作用。方法向小鼠气管内滴注LPS建立ALI模型,造模后1h sRAGE组腹腔注射100μg sRAGE,于24 h留取标本,检测各组动物支气管肺泡灌洗液(BALF)中白细胞及中性粒细胞数量、蛋白浓度和肿瘤坏死因子(TNF)α-水平,并对肺组织进行病理学观察。结果LPS滴注24 h后,BALF中白细胞总数和中性粒细胞数量显著增加,蛋白含量升高,TNFα-释放增多,肺组织出现典型的ALI病理损害,sRAGE干预显著降低了BALF中白细胞及中性粒细胞数量、蛋白含量和TNFα-水平,减轻了LPS引起的肺组织病理改变。结论应用sRAGE阻止RAGE信号通过抑制LPS引起的肺内中性粒细胞聚集、肺毛细血管渗出、炎症因子TNFα-释放,对ALI发挥保护作用。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号