S-allylmercaptocysteine ameliorates lipopolysaccharide-induced acute lung injury in mice by inhibiting inflammation and oxidative stress via nuclear factor kappa B and Keap1/Nrf2 pathways

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.     

Hydroxysafflor yellow A ameliorates lipopolysaccharide-induced acute lung injury in mice via modulating toll-like receptor 4 signaling pathways

Hydroxysafflor yellow A (HSYA) is a main bio-active compound important of a traditional Chinese medicine named Carthamus tinctorius L. and has been shown to possess various effects, especially anti-inflammatory benefits and potential protections against acute lung injury (ALI) in previous studies. Therefore, in this present study, we aimed to evaluating effects of HSYA on lipopolysaccharide (LPS)-induced ALI in mice. ALI was induced by intratracheal instillation of LPS into lung, and dexamethasone was used as a positive control. Results demonstrated that HSYA abated LPS-induced pathological change and attenuated lung vascular permeability and edema. HSYA down-regulated both the ability of myeloperoxidase (MPO) in lung tissues and levels of inflammatory mediators including tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6 and IFN(interferon)-β in serum. Moreover, HSYA prevented toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88) and TIR-domain-containing adapter-inducing interferon-β (TRIF) protein up-expressions. In addition, the activations of mitogen-activated protein kinases including p38, extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK) were blocked by HSYA. And also, the phosphorylations of interferon regulatory factor 3 (IRF3), translocation of nuclear factor kappa B (NF-κB)/p65 and inhibitory kappa B (IκB)-α were inhibited by HSYA. In conclusion, HSYA attenuated inflammatory response in ALI mice through inhibition of TLR 4-dependent signaling pathways.     

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

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

Hyaluronan ameliorates LPS-induced acute lung injury in mice via Toll-like receptor (TLR) 4-dependent signaling pathways

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.     

Hyperin inhibits nuclear factor kappa B and activates nuclear factor E2-related factor-2 signaling pathways in cisplatin-induced acute kidney injury in mice

Hyperin, a flavonoid compound found in Ericaceae, Guttiferae, and Celastraceae, has been reported to have anti-inflammatory effects. In the present study, we investigated the effects of hyperin on cisplatin-induced acute kidney injury (AKI) in mice. The renal tissue damage induced by cisplatin was detected by H&E staining. Blood urea nitrogen (BUN), creatinine, reactive oxygen species (ROS), and malondialdehyde (MDA) were also detected. Further, the effects of hyperin on cisplatin-induced TNF-α, IL-1β and IL-6 were detected by ELISA. In addition, the phosphorylation of nuclear factor kappa B (NF-κB) and the expression of nuclear factor E2-related factor-2 (Nrf2) and HO-1 were detected by western blot analysis. The results showed that hyperin attenuated histological changes of kidney induced by cisplatin. The levels of BUN, creatinine, ROS, MDA, TNF-α, IL-1β and IL-6 induced by cisplatin were also inhibited by hyperin. Cisplatin-induced NF-κB activation was inhibited by hyperin. Additionally, hyperin was found to up regulate the expression of Nrf2 and HO-1. In conclusion, the results suggest that hyperin protects against cisplatin-induced AKI by inhibiting inflammatory and oxidant response.     

甘草酸单铵对脂多糖致小鼠急性肺损伤的保护作用

采用脂多糖(lipopolysaccharide，LPS)气道滴入诱导小鼠急性肺损伤(acute lung injury，ALI)模型，研究甘草酸单铵(monoammonium glycyrrhizinate，MAG)对ALI的防治作用及其机制。雄性ICR小鼠随机分为生理盐水(NS)对照组、MAG 3、10 及30 mg·kg^-1组、LPS组、地塞米松(dexamethasone，DXM) 5 mg·kg^-1组。MAG各组气道滴入LPS前1 h及滴入后3 h各给药1次，DXM组气道滴入LPS前1 h给药1次。LPS气道滴入后6 h处死动物，测定各组的肺湿重/干重比、肺通透性、肺组织中性粒细胞髓过氧化物酶(myeloperoxidase，MPO)含量、ELISA法检测肺组织匀浆TNF-α、IL-10含量，常规细胞形态学检测中性粒细胞在支气管肺泡灌洗液(bronchoalveolar lavage fluid，BALF)中的比例和肺组织病理改变。结果表明，MAG剂量依赖性减轻气道内滴入LPS诱导的小鼠ALI程度，降低肺湿重/干重比及肺组织伊文斯蓝的渗出，降低BALF中白细胞总数和中性粒细胞数比例，抑制组织MPO的释放，降低肺组织匀浆TNF-α的含量，增加肺组织IL-10的释放。以上结果提示，MAG可能通过调节TNF-α/IL-10的平衡而有效保护脂多糖诱导的急性肺损伤。     

乌司他丁通过干预p38MAPK/ERK信号通路减轻脓毒症性肺损伤

目的探讨乌司他丁(ulinastatin,UTI)对脓毒症性急性呼吸窘迫综合征(acute respiratory distress syndrome,ARDS)大鼠的肺保护作用及可能机制。方法 56只Wistar大鼠按随机数字表法分为对照组、模型(LPS 6、12、24 h)组、乌司他丁(UTI 6、12、24 h)组,每组8只。采用腹腔注射细菌脂多糖(lipopolysaccharide,LPS,10 mg·kg~(-1))的方法制备大鼠ARDS模型,乌司他丁组在左侧腹腔注射LPS后1 h后,在右侧腹腔注射乌司他丁20 000 U·kg~(-1),对照组、注射同等剂量的生理盐水,各组大鼠在不同时间点留取肺组织及血浆标本。计算肺组织湿/干质量(W/D)比值;光镜下观察肺组织病理改变;用ELISA法检测各组血浆中肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)、白细胞介素~(-1)8(interleukin~(-1)8,IL~(-1)8)、肺表面活性物质A((surfactant protein A,SPA)含量,检测各组肺匀浆中丙二醛(malondialdehyde,MDA)、超氧化物歧化酶(superoxide Dismutase,SOD)和一氧化氮(nitric oxide,NO)含量;免疫组化法检测p38丝裂原活化蛋白激酶(mitogen activated protein kinase,p38MAPK)、细胞外信号调节蛋白激酶(extracellular-signal regulated protein kinase,ERK)蛋白表达情况;Western blot法检测肺组织中磷酸化p38MAPK(p-p38MAPK)及磷酸化ERK(p-ERK)蛋白表达的变化。结果光镜下观察对照组肺组织结构完整,肺泡腔清晰;LPS组肺泡壁增厚,渗出明显,肺组织出现损伤性变化,以12h组变化最明显;UTI组各组病理改变较LPS组明显减轻。与对照组比较,LPS组W/D比值、血浆TNF-α、IL~(-1)8含量,肺匀浆MDA、NO含量均明显升高(P<0.05),而肺匀浆SOD含量明显降低;与LPS组比较,UTI各组肺组织W/D比值、血浆TNF-α、IL~(-1)8含量,肺匀浆MDA含量均明显降低,而肺匀浆SOD含量明显增高,差异有统计学意义;免疫组化结果显示:与对照组比较,LPS组p38MAPK、ERK蛋白在胞质和胞核表达均明显增加,而UTI组较LPS组表达均明显减少;Western blot检测结果显示:与对照组比较,LPS组肺组织p-p38MAPK/ERK蛋白表达均明显增高,而UTI干预组蛋白表达均明显受抑制。结论乌司他丁通过干预p38MAPK/ERK信号通路、抗氧化作用而减轻炎症反应,发挥对LPS致脓毒性大鼠ARDS的保护作用。     

Shikonin exerts anti-inflammatory effects in a murine model of lipopolysaccharide-induced acute lung injury by inhibiting the nuclear factor-kappaB signaling pathway

Shikonin, an analog of naphthoquinone pigments isolated from the root of Lithospermum erythrorhyzon, was recently reported to exert beneficial anti-inflammatory effects both in vivo and in vitro. The present study aimed to investigate the potential therapeutic effect of shikonin in a murine model of lipopolysaccharide (LPS)-induced acute lung injury (ALI). Dexamethasone was used as a positive control to evaluate the anti-inflammatory effect of shikonin in the study. Pretreatment with shikonin (intraperitoneal injection) significantly inhibited LPS-induced increases in the macrophage and neutrophil infiltration of lung tissues and markedly attenuated myeloperoxidase activity. Furthermore, shikonin significantly reduced the concentrations of TNF-α, IL-6 and IL-1β in bronchoalveolar lavage fluid induced by LPS. Compared with the LPS group, lung histopathologic changes were less pronounced in the shikonin-pretreated mice. Additionally, Western blotting results showed that shikonin efficiently decreased nuclear factor-kappaB (NF-κB) activation by inhibiting the degradation and phosphorylation of IκBα. These results suggest that shikonin exerts anti-inflammatory properties in LPS-mediated ALI, possibly through inhibition of the NF-κB signaling pathway, which mediates the expression of pro-inflammatory cytokines. Shikonin may be a potential agent for the prophylaxis of ALI.     

基于cGAS-STING通路探讨知母皂苷元对脂多糖诱导的小鼠急性肺损伤保护作用

目的 研究知母皂苷元对脂多糖（LPS）诱导的小鼠急性肺损伤的保护作用。方法 将昆明小鼠随机分为对照组、模型组、地塞米松（0.5 mg/kg）组、知母皂苷元（50、100、200 mg/kg）组。知母皂苷元50、100、200 mg/kg组小鼠ig相应剂量知母皂苷元溶液,地塞米松组小鼠ip地塞米松磷酸钠注射液,对照组和模型组小鼠ig等体积生理盐水,1次/d,连续7 d。末次给药1 h后,其余各组小鼠除对照组外均ip 10 mg/kg LPS溶液复制小鼠急性肺损伤模型。6 h后取各组小鼠左肺组织,计算肺湿/干质量比（W/D）;采用苏木精-伊红（HE）染色法观察肺组织病理形态学变化;采用酶联免疫吸附测定法（ELISA）检测血清中肿瘤坏死因子-α（TNF-α）、白细胞介素-6（IL-6）水平;采用Western blotting法检测肺组织中鸟苷酸-腺苷酸合成酶（cGAS）、干扰素基因刺激因子（STING）的蛋白表达。结果 与模型组相比,知母皂苷元组小鼠左肺W/D值、血清中IL-6和TNF-α水平、肺组织中cGAS和STING的蛋白表达均显著降低（P<0.05）,肺组织病理学损伤均有所改善。结论 知母皂苷元可能通过抑制cGAS-STING通路,减少炎症因子TNF-α、IL-6的分泌,从而保护LPS诱导的急性肺损伤。     

The novel N-methyl-d-aspartate receptor antagonist MN-08 ameliorates lipopolysaccharide-induced acute lung injury in mice

Acute lung injury (ALI) is a clinically severe respiratory disorder, and effective therapy is urgently needed. MN-08, a novel synthetic N-methyl-d-aspartate receptor (NMDAR) antagonist, was investigated for its effect on lipopolysaccharide (LPS)-induced ALI. In vitro, the protective effect of MN-08 on inflammatory response, oxidative stress, and tight junctions (TJs) structure was explored in LPS-induced RAW 264.7 cells and A549 cells. MN-08 markedly decreased (p < 0.001) the levels of pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), and reactive oxygen species (ROS), whereas it moderately upregulated (p < 0.05) heme oxygenase (HO)-1 protein expression in LPS-induced RAW 264.7 cells. Moreover, MN-08 significantly inhibited (p < 0.001) cell apoptosis and improved (p < 0.001) protein expression of TJs in LPS-induced A549 cells. In vivo, the therapeutic effect of MN-08 was evaluated in the LPS-induced ALI model through intratracheal instillation in BALB/c mice. MN-08 administration dramatically attenuated (p < 0.001) pulmonary pathological changes and reduced (p < 0.001) the levels of glutamate, myeloperoxidase (MPO), malondialdehyde (MDA), and number of cells in BALF, whereas it increased (p < 0.05) superoxide dismutase (SOD) and glutathione (GSH) activities in ALI mice. Furthermore, MN-08 markedly blocked the mitogen-activated protein kinases (MAPKs)/nuclear translocation of nuclear factor-κB (NF-κB) signaling pathways in RAW 264.7 cells and lung tissues. These results indicate that MN-08 exhibits lung protection in an LPS-induced ALI model via anti-inflammatory and anti-oxidative activities.     

氨基胍对内毒素性肺损伤炎症反应和NF-κB信号通路的影响

目的观察选择性一氧化氮合酶抑制剂氨基胍(aminogunidine,AG)对大鼠内毒素性肺损伤(acute lung injury,ALI)NF-κB相关信号通路和炎症反应的影响,探讨AG对肺损伤组织的保护作用及其机制。方法健康♂SD大鼠随机分为对照组、模型组和AG治疗组。模型组、AG治疗组静脉注射脂多糖(lipopolysaccharide,LPS)复制内毒素性肺损伤模型。各组按治疗时间又分为给LPS3h后治疗3h(3h+3h)组和给LPS6h后治疗3h(6h+3h)组,分别于给LPS3h和6h后腹腔注射生理盐水(对照组及LPS组)和AG(100mg.kg-1,AG治疗组)。每组8只动物。免疫组化染色分析肺组织中核因子-κB(NF-κB)的核移位和粘附分子-1(ICAM-1)表达;放射免疫法分别测定肺组织中肿瘤坏死因子α(TNF-α)和白介素6(IL-6)的含量;光镜、电镜观察肺组织病理变化。结果与对照组比较,大鼠肺损伤后NF-κB活化,明显从细胞质移位于细胞核,表达量也明显增加;ICAM-1蛋白表达增加;肺组织中TNF-α、IL-6含量明显升高。肺损伤3h用AG治疗3h后,NF-κB从细胞质向细胞核的移位被明显限制,NF-κB的表达量、ICAM-1蛋白表达和肺组织中TNF-α、IL-6含量明显低于相应的LPS组,肺组织病理改变减轻;肺损伤6h用AG治疗3h后,治疗效果较差。结论AG于LPS3h后给药可减轻内毒素性肺损伤,可能与减弱诱导型一氧化氮合酶(iNOS)mRNA表达、抑制核因子的活化,在一定程度上阻断NF-κB相关信号通路的传导,下调炎症因子和ICAM-1的表达有关。     

西地那非对脂多糖诱导的小鼠急性肺损伤的作用

目的明确西地那非对急性肺损伤(ALI)的治疗作用及可能机制。方法采用脂多糖(LPS,4 mg·kg~(-1))气道滴入诱导的小鼠ALI模型。随机分为生理盐水组、LPS模型组、西地那非3,10及30 mg·kg~(-1)组、地塞米松5 mg·kg~(-1)组。测定肺干/湿重比值,常规细胞形态学检测支气管肺泡灌洗液(BALF)中白细胞,肺组织切片观察病理改变;测定肺组织匀浆髓过氧化酶(MPO)活性、NO含量、NOS活性及TNF-α含量。结果LPS诱导的ALI小鼠肺干/湿重比值明显下降;BALF中白细胞总数及中性粒细胞比例明显增加;肺毛细血管通透性明显增加;肺组织间隙大量中性粒细胞浸润和红细胞渗出;肺组织匀浆TNF-α含量和MPO活性明显增加,NO含量、总NOS活性及iNOS活性明显增加。同时腹腔注射西地那非可剂量依赖性地降低ALI小鼠肺干/湿重比值;减少BALF中的白细胞总数及中性粒细胞的比例;降低肺毛细血管通透性;改善肺组织病理变化;抑制肺组织匀浆TNF-α含量、MPO活性及NO含量、总NOS活性及iNOS活性的增加。结论西地那非对LPS诱导的ALI有保护作用,提示NO- cGMP途径可能在ALI中起重要作用。     

Ethyl ferulate protects against lipopolysaccharide-induced acute lung injury by activating AMPK/Nrf2 signaling pathway

Ethyl ferulate (EF) is abundant in Rhizoma Chuanxiong and grains (e.g.,rice and maize) and possesses antioxidative,antiapoptotic,antirheumatic,and anti-inflamma...     

地昔帕明对小鼠内毒素急性肺损伤的影响

目的探讨地昔帕明(DP)对脂多糖(LPS)引起的急性肺损伤的作用并初步探讨其作用机制。方法昆明种小鼠随机分为生理盐水对照组(NS组)、地昔帕明对照组(DP组)、模型组(LPS组)及地昔帕明处理组(DP+LPS组)。腹腔注射LPS建立小鼠急性肺损伤模型。造模6h后测定肺湿/干重比值(W/D)、肺泡灌洗液(BALF)中白细胞数和蛋白含量、肺组织匀浆中髓过氧化物酶(MPO)活性和丙二醛(MDA)水平,同时用ELISA法检测肺匀浆中肿瘤坏死因子-α(TNF-α)含量。结果LPS可提高小鼠肺W/D、BALF中白细胞数和蛋白含量、肺匀浆MPO活性、MDA和TNF-α含量(P<0.01),DP处理组可有效减轻LPS所引起的上述变化(P<0.05)。结论DP对LPS导致的小鼠急性肺损伤有保护作用,其保护机制可能与抑制肺TNF-α的产生,进而减轻中性粒细胞的肺部扣押和肺组织脂质过氧化损伤的程度有关。     

阿托伐他汀钙对脂多糖诱导急性肺损伤小鼠核因子E2相关因子2/血红素加氧酶-1通路的影响

目的 探讨阿托伐他汀钙(AVT)对脂多糖(LPS)诱导急性肺损伤(ALI)小鼠核因子E2相关因子2/血红素加氧酶-1(Nrf2/HO-1)通路的影响。方法 2021年9―12月,采用随机数字表法把15只BALB/c雌性小鼠分为NS组(尾静脉注射生理盐水)、LPS组(尾静脉注射LPS诱导ALI模型)、LPS+AVT组(经AVT灌胃治疗的ALI模型),每组各5只。收集动脉血,测定血氧分压(PaO₂)、氧合指数(PaO₂/FiO₂);处死后取出双肺,HE染色观察肺组织,测定湿干重比(W/D),酶联免疫吸附(ELISA)法测肺泡灌洗液(BALF)中白细胞介素-1β(IL-1β)、肿瘤坏死因子-α(TNF-α)含量,蛋白质印迹法(Western blotting)测肺组织中Nrf2、HO-1的表达。结果 NS组、LPS组及LPS+AVT组PaO₂ [(89.66±8.54)、(50.88±6.26)、(67.84±5.76)mmHg]、PaO₂/FiO₂[(426....     

Soyasaponin Ab inhibits lipopolysaccharide-induced acute lung injury in mice

Soyasaponin Ab (SA) has been reported to have anti-inflammatory effect. However, the effects of SA on lipopolysaccharide (LPS)-induced acute lung injury (ALI) have not been reported. The aim of this study was to investigate the anti-inflammatory effects of SA on LPS-induced ALI and clarify the possible mechanism. The mice were stimulated with LPS to induce ALI. SA was given 1 h after LPS treatment. 12 h later, lung tissues were collected to assess pathological changes and edema. Bronchoalveolar lavage fluid (BALF) was collected to assess inflammatory cytokines and nitric oxide (NO) production. In vitro, mice alveolar macrophages were used to investigate the anti-inflammatory mechanism of SA. Our results showed that SA attenuated LPS-induced lung pathological changes, edema, the expression of cycloxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) in lung tissues, as well as TNF-α, IL-6, IL-1β, and NO production in mice. Meanwhile, SA up-regulated the activities of superoxide dismutase (SOD) and catalase decreased by LPS in mice. SA also inhibited LPS-induced TNF-α, IL-6 and IL-1β production as well as NF-κB activation in alveolar macrophages. Furthermore, SA could activate Liver X Receptor Alpha (LXRα) and knockdown of LXRα by RNAi abrogated the anti-inflammatory effects of SA. In conclusion, the current study demonstrated that SA exhibited protective effects against LPS-induced acute lung injury and the possible mechanism was involved in activating LXRα, thereby inhibiting LPS-induced inflammatory response.     

姜黄素抑制HMGB1-NF-κB信号通路减轻脂多糖诱导新生大鼠急性肺损伤实验研究

目的 分析姜黄素抑制高迁移率族蛋白B1（HMGB1）-核转录因子κB（NF-κB）信号通路减轻脂多糖（LPS）诱导新生大鼠急性肺损伤（ALI）的作用。方法 将60只新生SD雄性大鼠随机分为对照组、模型组、地塞米松（阳性药,2 mg·kg^-1）组和姜黄素低、中、高剂量（1.5、3.0、6.0 mg·kg^-1）组,每组10只。除对照组外,所有大鼠采用腹膜内注射LPS （3 mg·kg^-1）建立ALI模型。注射LPS约6 h后开始ip给药,每天1次,连续7 d,模型组和对照组大鼠ip等体积的0.1% DMSO。通过血氧分压（PaO₂）和肺干湿质量比（W/D）评估新生大鼠肺水肿情况;HE染色检测各组大鼠肺组织损伤;ELISA法检测新生大鼠支气管肺泡灌洗液（BALF）氧化应激指标超氧化物歧化酶（SOD）、髓过氧化物酶（MPO）、丙二醛（MDA）和谷胱甘肽（GSH）水平,BALF中白细胞介素-6（IL-6）、肿瘤坏死因子-α（TNF-α）和HMGB1水平;Western blotting法检测大鼠肺组织胞核NF-κB、胞浆NF-κB和磷酸化核因子κB抑制因子α（p-IκBα）蛋白表达。结果 与对照组相比,模型组新生大鼠肺泡腔有渗出、肺组织结构紊乱、细胞核固缩深染、伴随大量的炎性细胞浸润,病理评分显著升高（P<0.01）; PaO₂、BALF中SOD和GSH水平显著降低（P<0.01）;肺W/D,BALF中MPO和MDA水平,BALF中IL-6、TNF-α和HMGB1水平,NF-κB胞核/胞浆比例和胞浆p-IκBα蛋白表达水平显著升高（P<0.01）。与模型组相比,姜黄素高、中剂量组和地塞米松组大鼠肺组织病理损伤减轻,肺泡腔渗出、炎性细胞浸润明显减少,病理评分显著降低（P<0.05、0.01）; PaO₂、BALF中SOD和GSH水平显著升高（P<0.05、0.01）;肺W/D,BALF中MPO、MDA水平,BALF中IL-6、TNF-α和HMGB1水平,NF-κB胞核/胞浆比例和胞浆p-IκBα蛋白表达水平显著降低（P<0.05、0.01）。结论 姜黄素可以通过抑制HMGB1-NF-κB信号通路减轻LPS诱导的新生大鼠ALI。     

Lactoferrin protects against lipopolysaccharide-induced acute lung injury in mice

Lactoferrin (LF) plays various anti-inflammatory roles in inflammation experimentally induced by lipopolysaccharides (LPS). But the protective effects of LF on LPS-induced acute lung injury (ALI) have not been elucidated. In this study, we aimed to study the effects of LF on ALI caused by LPS in mice. At 1h before or after LPS injection, an intraperitoneal injection of LF (5mg/body) was administered. Lung specimens and the bronchoalveolar lavage fluid (BALF) were isolated for histopathological examinations and biochemical analyses 12h after LPS exposure. We found that both prophylactic and therapeutic administration of LF significantly decreased the W/D ratio of the lung and protein concentration in the BALF. LF significantly reduced the pulmonary myeloperoxidase activity and the number of total cells in the BALF 12h after LPS challenge. LF treatment markedly attenuated lung edema, alveolar hemorrhage and inflammatory cells infiltration. Moreover, LF also decreased the production of TNF-α and increased interleukin-10 in the BALF. These results firstly indicate that LF may protect against LPS-induced ALI in mice.     

Hydrogen inhalation ameliorates lipopolysaccharide-induced acute lung injury in mice

Acute lung injury (ALI) is a serious illness, the incidence and mortality of which are very high. Free radicals, such as hydroxyl radicals (OH) and peroxynitrite (ONOO⁻), are considered to be the final causative molecules in the pathogenesis of ALI. Hydrogen, a new antioxidant, can selectively reduce OH and ONOO⁻. In the present study, we investigated the hypothesis that hydrogen inhalation could ameliorate ALI induced by intra-tracheal lipopolysaccharide (LPS, 5 mg/kg body weight). Mice were randomized into three groups: sham group (physiological saline + 2% hydrogen mixed gas), control group (LPS + normal air) and experiment group (LPS + 2% hydrogen mixed gas). Bronchoalveolar lavage fluid (BALF) was performed to determine the total protein concentrations and pro-inflammatory cytokines. Lung tissues were assayed for oxidative stress variables, wet/dry (W/D) ratio, histological, immunohistochemistry and Western blotting examinations. Our experiments exhibited that hydrogen improved the survival rate of mice and induced a decrease in lung W/D ratio. In addition, hydrogen decreased malonaldehyde and nitrotyrosine content, inhibited myeloperoxidase and maintained superoxide dismutase activity in lung tissues and associated with a decrease in the expression of TNF-α, IL-1β, IL-6 and total protein concentrations in the BALF. Hydrogen further attenuated histopathological alterations and mitigated lung cell apoptosis. Importantly, hydrogen inhibited the activation of P-JNK, and also reversed changes in Bax, Bcl-xl and caspase-3. In conclusion, our data demonstrated that hydrogen inhalation ameliorated LPS-induced ALI and it may be exerting its protective role by preventing the activation of ROS–JNK–caspase-3 pathway.