麻黄碱对脂多糖诱导的小胶质细胞功能损伤的修复作用及机制

目的 研究麻黄碱对脂多糖（LPS）诱导的小胶质细胞功能损伤的修复作用及机制。方法 以人小胶质细胞HMC3为研究对象,考察不同质量浓度麻黄碱（75、150、300、600μg/mL）对HMC3细胞活力和凋亡的影响。然后将HMC3细胞分为对照组（不受药物干预）、LPS组（1μg/mL）、麻黄碱组（1μg/mL LPS+300μg/mL麻黄碱）、BAY11-7082组[1μg/mL LPS+5μmol/L核因子κB(NF-κB)信号通路抑制剂BAY11-7082]、抑制剂组（1μg/mL LPS+300μg/mL麻黄碱+5μmol/L BAY11-7082）和激活剂组（1μg/mL LPS+300μg/mL麻黄碱+1μmol/L NF-κB信号通路激活剂Prostratin）,加入相应药物作用24 h后,检测细胞迁移能力和细胞中可溶性白细胞介素6(s IL-6)、白细胞介素10(IL-10)、超氧化物歧化酶（SOD）、丙二醛（MDA）水平以及NF-κB信号通路相关蛋白表达水平。结果 300μg/mL的麻黄碱可使HMC3细胞活力显著升高、凋亡率显著降低（P<0.05）。与对照组相比,LP...     

三叶青黄酮经p38MAPK和NF-κB途径抑制老年小鼠急性肺损伤

目的探讨三叶青总黄酮(RTFs)对老年小鼠急性肺损伤(ALI)的保护作用及可能机制。方法采用老年C57BL/6J小鼠支气管滴注脂多糖(LPS)诱导ALI模型,三叶青黄酮灌胃给药3 d。取支气管肺泡灌洗液(BALF),瑞氏-吉姆萨染色计算白细胞数,ELISA检测炎症因子水平;ELISA和Western blot分析肺组织MAPKs、NF-κB蛋白表达,Trans AM检测核蛋白NF-κB活性。结果支气管滴注LPS成功诱导ALI模型,三叶青黄酮可明显减少BALF中白细胞和中性粒细胞数(P<0.01),降低IL-1β、IL-6、IL-12p40、TNF-α和s TNF-R1的分泌水平(P<0.01),改善肺组织病理损伤。三叶青黄酮明显抑制肺组织p38MAPK、NF-κB的磷酸化及NF-κB的DNA结合活性(P<0.01)。结论三叶青黄酮抑制p38MAPK、NF-κB炎症通路,保护LPS诱导的老年小鼠ALI。     

三叶青黄酮经p38MAPK和NF-κB途径抑制老年小鼠急性肺损伤北大核心CSCD

目的探讨三叶青总黄酮(RTFs)对老年小鼠急性肺损伤(ALI)的保护作用及可能机制。方法采用老年C57BL/6J小鼠支气管滴注脂多糖(LPS)诱导ALI模型,三叶青黄酮灌胃给药3 d。取支气管肺泡灌洗液(BALF),瑞氏-吉姆萨染色计算白细胞数,ELISA检测炎症因子水平;ELISA和Western blot分析肺组织MAPKs、NF-κB蛋白表达,Trans AM检测核蛋白NF-κB活性。结果支气管滴注LPS成功诱导ALI模型,三叶青黄酮可明显减少BALF中白细胞和中性粒细胞数(P<0.01),降低IL-1β、IL-6、IL-12p40、TNF-α和s TNF-R1的分泌水平(P<0.01),改善肺组织病理损伤。三叶青黄酮明显抑制肺组织p38MAPK、NF-κB的磷酸化及NF-κB的DNA结合活性(P<0.01)。结论三叶青黄酮抑制p38MAPK、NF-κB炎症通路,保护LPS诱导的老年小鼠ALI。     

银杏内酯B对脂多糖刺激的小鼠腹腔巨噬细胞TNFα生成及大鼠胸腔多形核白细胞NF-кB活化的影响

目的研究银杏内酯B对脂多糖刺激的小鼠腹腔巨噬细胞TNFα生成及大鼠胸腔多形核白细胞NF-κB活化的影响.方法用L929细胞结晶紫染色法检测TNFα的含量,用电泳迁移率改变检测法检测NF-κB的结合活性.结果1和10 μmol·L-1银杏内酯R能够显著抑制LPS刺激的小鼠腹腔巨噬细胞TNFα的生成,其IC50为0.26μmol·L-1:1 mg·L-1LPS和1 nmol·L-1PAF均可活化大鼠胸腔多形核白细胞NF-κB;银杏内酯B能够抑制LPS或PAF刺激的NF-κR活化.结论银杏内酯B能够抑制LPS刺激的小鼠腹腔巨噬细胞TNFα生成及大鼠胸腔多形核白细胞NF-κB的活化.PAF参与LPS激活NF-κB的过程.     

可溶性晚期糖基化终末产物受体对脂多糖肺损伤小鼠肺内细胞因子的干预作用

目的探讨应用重组可溶性晚期糖基化终末产物受体(sRAGE)对脂多糖(LPS)介导的急性肺损伤(ALI)小鼠肺内细胞因子水平的影响。方法健康雄性BALB/C小鼠随机分为磷酸盐缓冲液(PBS)组、LPS组和sRAGE组。LPS组和sRAGE组通过气管内滴注LPS(3mg/kg体质量)建立ALI模型,造模后1hsRAGE组腹腔注射100μg重组小鼠sRAGE,各组于24h留取标本,采用Bio-Plex悬浮芯片技术检测支气管肺泡灌洗液(BALF)中8种细胞因子含量,并计数炎症细胞数量和蛋白(TP)含量,对肺组织进行病理学评估。观察sRAGE干预对造模后4h肺组织核因子(NF)-κB P65DNA结合活性的影响。结果 LPS滴注24h后,BALF中8种细胞因子含量均显著升高,白细胞(WBC)总数和中性粒细胞(NEU)数量显著增加,TP含量升高,肺组织出现典型的ALI病理损害。sRAGE干预显著降低了BALF中肿瘤坏死因子(TNF)-α、巨噬细胞炎症蛋白(MIP)-1β和MIP-1α水平,减少了BALF中WBC、NEU数量及TP含量,减轻了LPS引起的肺组织病理改变,并对造模后4hLPS介导的肺内NF-κB活化有抑制作用。结论应用重组sRAGE阻止RAGE信号能调控LPS介导的肺内细胞因子的表达,这构成了sRAGE抑制肺内炎症的重要机制之一。     

三甲氧基二苯乙烯对小鼠巨噬细胞产肿瘤坏死因子-α及细胞核因子-κB活性的作用研究

目的研究三甲氧基二苯乙烯（BTM）对小鼠巨噬细胞经脂多糖（LPS）诱导后产生肿瘤坏死因子-α（TNF-α）及细胞核因子-κB（NF-κB）活化的调控作用。方法培养RAW246．7小鼠巨噬细胞,加入不同浓度的BTM或白藜芦醇,再加入LPS活化细胞,收集细胞上清液用L929细胞结晶紫染色法检测TNF-α的活性,制作细胞爬片用免疫细胞化学法检测巨噬细胞中NF-κB的表达。结果BTM和白藜芦醇本身对L929细胞无细胞毒性;经不同浓度BTM和白藜芦醇处理后巨噬细胞产生TNF-α的水平及表达NF-κB的阳性率呈剂量依赖性减少,BTM抑制巨噬细胞产生TNF-α及表达NF-κB的能力大于白藜芦醇,巨噬细胞产生TNF-α的活性及NF-κB的阳性细胞率均与药物浓度呈负相关,TNF-α的活性和NF-κB的阳性细胞率呈正相关。结论BTM和白藜芦醇在浓度为5～80μmol／L范围内,呈浓度依赖性地通过抑制NF-κB的活化来抑制TNF-α的产生,且BTM抑制巨噬细胞产生TNF-α和NF-κB活化的能力犬于白藜芦醇。     

右美托咪定对LPS诱导大鼠肺泡Ⅱ型上皮细胞NF-κB及AQP-5表达的影响

目的研究右美托咪定(DEX)对脂多糖(LPS)诱导的大鼠肺泡Ⅱ型上皮(AT-Ⅱ)细胞核转录因子-κB(NF-κB)及水通道蛋白5(AQP-5)的影响。方法原代培养大鼠AT-Ⅱ细胞,建立LPS诱导急性肺损伤细胞(ALI)模型,实验分为对照组、LPS组(1μg·mL^-1)、LPS+DEX(0.1 ng·mL^-1、1 ng·mL^-1、10 ng·mL^-1)组。对照组置于正常条件下培养,LPS+DEX组在加入LPS前1 h分别加入相应浓度的右美托咪定,培养24 h后,MTT检测AT-Ⅱ细胞存活率,采用试剂盒测定各细胞上清液中乳酸脱氢酶(LDH)的含量,Real-time qPCR、Western blotting分别检测各组NF-κB及AQP-5的mRNA和蛋白表达水平。结果LPS可导致AT-Ⅱ细胞损伤,降低细胞存活率,增加LDH释放;右美托咪定可在0.1~10 ng·mL^-1内以浓度依赖性提高损伤细胞的存活率,减少LDH的释放,抑制LPS诱导的AT-Ⅱ细胞中NF-κB的活化,上调AQP-5的表达。结论右美托咪定对LPS所致AT-Ⅱ细胞损伤具有保护作用,其作用机制可能是下调NF-κB表达以及上调AQP-5表达。     

DATS通过NF-κB抑制LPS诱导小鼠肺泡巨噬细胞促炎细胞因子表达

目的探讨二烯丙基三硫(DATS)抑制脂多糖(LPS)诱导小鼠肺泡巨噬细胞肿瘤坏死因子-α(TNF-α)及白介素-1β表达的信号转导机制。方法体外培养MH-S细胞,用DATS和(或)LPS进行干预。反转录PCR检测细胞中TNF-α、IL-1β mRNA表达,电泳迁移率改变分析(EMSA)检测细胞核因子-κB(NF-κB)活性,Western blot检测细胞磷酸化(p-IκB)及非磷酸化IκB的表达。结果LPS刺激MH-S细胞可导致TNF-α、IL-1β mRNA、p-IκB表达增加及NF-κB活性升高。用DATS(0.1、0.5、2.5、5.0mg.L-1)预处理细胞30min后再给予LPS刺激,可使TNF-α、IL-1β mRNA表达降低,并呈剂量依赖性;升高的NF-κB活性及p-IκB表达均显不同程度的抑制。单独DATS对TNF-α、IL-1β mRNA表达及NF-κB活性无影响。结论DATS可通过抑制IκB磷酸化及NF-κB活化,进而下调LPS诱导小鼠肺泡巨噬细胞TNF-α、IL-1β mRNA表达。     

氯胺酮对内毒素大鼠体外血单核细胞的作用

目的 研究氯胺酮对内毒素诱导的大鼠外周单个核细胞（PBMC）NF-κB激活和TNF-α产生的影响。方法 PBMC分为对照组、内毒素刺激组（LPS10μg／ml）、氯胺酮治疗组（PLS10μg／ml＋氯胺酮1、10、100、1000、5000μM／ml）。用凝胶电迁移（EMSA）方法测定1h的细胞内NF-κB的水平,用蛋白免疫印迹（Western blot）方法测定1h细胞浆内NF-κB抑制因子IκBa的水平。用酶联免疫吸附实验（ELISA）分别测定1、4、6h时TNF-α的水平。结果 LPS在体外刺激大鼠PBMC后可显著性增加TNF-α的产生和细胞核内NF-κB的激活水平,同时降低胞浆内IκBa的含量。应用氯胺酮后可明显降低PBMC细胞核内NF-κB的激活水平,并抑制TNF-α的产生,但无明显的剂量依赖效应。结论 氯胺酮可抑制LPS所诱导的大鼠PBMC中NF-κB的激活和TNF-α的产生。     

核因子-κB特异性抑制剂小白菊内酯在大鼠心肌组织的药效时间

目的观察核因子-κB(NF-κB)特异性抑制剂小白菊内酯(PTN)在大鼠心肌组织中的药效作用时间。方法健康雄性SD大鼠40只随机分为5组:空白对照组、PTN组、二甲亚砜(DMSO)组、脂多糖(LPS)组和PTN+LPS组。第1天:PTN组、DMSO组和PTN+LPS组大鼠分别腹腔内注射PTN(500μg/kg)和PTN溶剂DMSO(相等容量);其余各组腹腔内注射相等容量的生理盐水。第2天(即PTN注射后24 h):LPS组和PTN+LPS组大鼠经皮下注射LPS(12.5 mg/kg);其余各组经皮下注射相等容量的生理盐水。每组在相当于注射LPS后1 h时取出心脏,采用Westernblot法分析心肌细胞细胞核内NF-κB p50和细胞浆中抑制蛋白(IκBα)、磷酸化抑制蛋白(p-IκBα)表达变化。结果与空白对照相比,PTN组和DMSO组NF-κB p50I、κBα和p-IκBα表达差异无统计学意义,而LPS组和PTN+LPS组NF-κBp50表达上调(P<0.05),IκBα表达下调(P<0.05),p-IκBα表达上调(P<0.05)。结论LPS刺激可在1 h内激活NF-κB,PTN(500μg/kg)在大鼠体内代谢24 h后未见明显药效。     

丙泊酚对体外内毒素激活人中性粒细胞NF-κB亚单位p65蛋白的影响

目的观察丙泊酚对内毒素(LPS)激活后人体中性粒细胞(PMN)NF-κB p65的表达及对PMN凋亡的影响。方法采集20例健康志愿者外周静脉血,分离PMN后分为五组:C组,加入生理盐水作为对照;LPS组,加入LPS 100ng/L);P1组,LPS+丙泊酚2μg/ml;P2组,LPS+丙泊酚4μg/ml;P3组,LPS+丙泊酚8μg/ml。孵育2.5h后,提取RNA;用RT-PCR法检测p65mRNA,Western blot检测p65蛋白含量,流式细胞术检测PMN凋亡。结果 LPS 100ng/L可以显著激活PMN,使p65表达大量增加。实验剂量的丙泊酚均可不同程度抑制LPS激活后PMN p65的表达(P<0.05);2-8μg/ml浓度的丙泊酚可剂量依赖性增加LPS导致的PMN凋亡(P<0.05或P<0.01)。结论丙泊酚2-8μg/ml可抑制PMN p65的激活,促进LPS激活后的PMN凋亡。     

Ketamine attenuates sepsis-induced acute lung injury via regulation of HMGB1-RAGE pathways

High mobility group box protein 1 (HMGB1) and receptor for the advanced glycation end product (RAGE) play important roles in the development of sepsis-induced acute lung injury (ALI). Ketamine is considered to confer protective effects on ALI during sepsis. In this study, we investigated the effects of ketamine on HMGB1-RAGE activation in a rat model of sepsis-induced ALI. ALI was induced in wild type (WT) and RAGE deficient (RAGE^−/−) rats by cecal ligation and puncture (CLP) or HMGB1 to mimic sepsis-induced ALI. Rats were randomly divided to six groups: sham-operation + normal saline (NS, 10 mL/kg), sham-operation + ketamine (10 mg/kg), CLP/HMGB1 + NS (10 mL/kg), CLP/HMGB1 + ketamine (5 mg/kg), CLP/HMGB1 + ketamine (7.5 mg/kg), and CLP/HMGB1 + ketamine (10 mg/kg) groups. NS and ketamine were administered at 3 and 12 h after CLP/HMGB1 via intraperitoneal injection. Pathological changes of lung, inflammatory cell counts, expression of HMGB1and RAGE, and concentrations of various inflammatory mediators in bronchoalveolar lavage fluids (BALF) and lung tissue were then assessed. Nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinases (MAPK) signaling pathways in the lung were also evaluated. CLP/HMGB1 increased the wet to dry weight ratio and myeloperoxidase activity in lung, the number of total cells, neutrophils, and macrophages in the BALF, and inflammatory mediators in the BALF and lung tissues. Moreover, expression of HMGB1and RAGE in lung tissues was increased after CLP. Ketamine inhibited all the above effects. It also inhibited the activation of IκB-α, NF-κB p65, and MAPK. Ketamine protects rats against HMGB1-RAGE activation in a rat model of sepsis-induced ALI. These effects may partially result from reductions in NF-κB and MAPK.     

Differential Cell Sensitivity between OTA and LPS upon Releasing TNF-α

The release of tumor necrosis factor α (TNF-α) by ochratoxin A (OTA) was studied in various macrophage and non-macrophage cell lines and compared with E. coli lipopolysaccharide (LPS) as a standard TNF-α release agent. Cells were exposed either to 0, 2.5 or 12.5 μmol/L OTA, or to 0.1 μg/mL LPS, for up to 24 h. OTA at 2.5 μmol/L and LPS at 0.1 μg/mL were not toxic to the tested cells as indicated by viability markers. TNF-α was detected in the incubated cell medium of rat Kupffer cells, peritoneal rat macrophages, and the mouse monocyte macrophage cell line J774A.1: TNF-α concentrations were 1,000 pg/mL, 1,560 pg/mL, and 650 pg/mL, respectively, for 2.5 μmol/L OTA exposure and 3,000 pg/mL, 2,600 pg/mL, and 2,115 pg/mL, respectively, for LPS exposure. Rat liver sinusoidal endothelial cells, rat hepatocytes, human HepG2 cells, and mouse L929 cells lacked any cytokine response to OTA, but showed a significant release of TNF-α after LPS exposure, with the exception of HepG2 cells. In non-responsive cell lines, OTA lacked both any activation of NF-κB or the translocation of activated NF-κB to the cell nucleus, i.e., in mouse L929 cells. In J774A.1 cells, OTA mediated TNF-α release via the pRaf/MEK 1/2-NF-κB and p38-NF-κB pathways, whereas LPS used pRaf/MEK 1/2-NF-κB, but not p38-NF-κB pathways. In contrast, in L929 cells, LPS used other pathways to activate NF-κB. Our data indicate that only macrophages and macrophage derived cells respond to OTA and are considered as sources for TNF-α release upon OTA exposure.     

Hyaluronan inhibits Akt, leading to nuclear factor-κB down-regulation in lipopolysaccharide-stimulated U937 macrophages

Hyaluronan (HA) of high molecular weight is used in the treatment of osteoarthritis and rheumatoid arthritis by intra-articular injection. While HA has been shown to suppress nuclear factor (NF)-κB activation by proinflammatory cytokines and lipopolysaccharide (LPS), intracellular upstream events that cause NF-κB down-regulation in response to HA remain unclear. Thus, this study was performed to investigate the involvement of phosphoinositide-3-OH kinase (PI3K)/Akt in the inhibition of the LPS-activated NF-κB pathway by HA in U937 macrophages. In adherent U937 macrophage cultures, pretreatment with HA of 2700 kDa (1 mg/ml, 1 h) significantly inhibited interleukin-6 (IL-6) production by LPS (200 ng/ml, 24 h)-stimulated U937 cells. LPS (200 ng/ml) activated Akt and NF-κB, whereas HA (1 mg/ml) down-regulated LPS-stimulated phosphorylation of Akt and NF-κB. Inhibition studies using LY294002 (20 μM) revealed the requirement of the PI3K/Akt pathway for LPS-stimulated IL-6 production and NF-κB activation. Pretreatment with anti-intercellular adhesion molecule-1 (ICAM-1) antibody (20 μg/ml) reversed the inhibitory effects of HA on LPS-induced production of IL-6 and activation of Akt and NF-κB. Herein, we provided the first evidence that HA suppresses the LPS-activated PI3K/Akt pathway, leading to down-regulation of NF-κB with diminished IL-6 production through interaction with ICAM-1.     

Kaempferol regulates MAPKs and NF-κB signaling pathways to attenuate LPS-induced acute lung injury in mice

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.     

Therapeutic effect of methyl salicylate 2-O-β-d-lactoside on LPS-induced acute lung injury by inhibiting TAK1/NF-kappaB phosphorylation and NLRP3 expression

Acute lung injury (ALI), characterized by pulmonary edema and inflammatory cell infiltration, is a common syndrome of acute hypoxemic respiratory failure. Methyl salicylate 2-O-β-d-lactoside (MSL), a natural derivative of salicylate extracted from Gaultheria yunnanensis (Franch.) Rehder, was reported to have potent anti-inflammatory effects on the progression of collagen or adjuvant-induced arthritis in vivo and in vitro. The aim of this study is to investigate the therapeutic effect of MSL on lipopolysaccharide (LPS)-induced acute lung injury and reveal underlying molecular mechanisms. Our results showed that MSL significantly ameliorated pulmonary edema and histological severities, and inhibited IL-6 and IL-1β production in LPS-induced ALI mice. MSL also reduced MPO activity in lung tissues and the number of inflammatory cells in BALF. Moreover, we found that MSL significantly inhibited LPS-induced TAK1 and NF-κB p65 phosphorylation, as well as the expression of NLRP3 protein in lung tissues. Furthermore, MSL significantly inhibited LPS-induced TAK1 and NF-κB p65 phosphorylation in Raw264.7 cells. In addition, MSL significantly inhibited nuclear translocation of NF-κB p65 in cells treated with LPS in vitro. Taken together, our results suggested that MSL exhibited a therapeutic effect on LPS-induced ALI by inhibiting TAK1/NF-κB phosphorylation and NLRP3 expression.     

Anti-inflammatory effect of Yam Glycoprotein on lipopolysaccharide-induced acute lung injury via the NLRP3 and NF-κB/TLR4 signaling pathway

Acute lung injury (ALI) is a common lung disease accompanied by acute and persistent pulmonary inflammatory response syndrome, which leads to alveolar epithelial cells and capillary endothelial cell damage. Yam glycoprotein, separated from traditional Chinese yam, has been shown to have anti-inflammatory and immunomodulatory effects. In this experiment, we mainly studied the therapeutic effect and mechanism of a glycoprotein on the lipopolysaccharide (LPS)-induced ALI mice. An oral glycoprotein method was used to treat the mouse ALI model induced by LPS injection in the peritoneal cavity. Afterward, we measured the wet/dry (W/D) ratio, the activity of myeloperoxidase (MPO), the oxidative index superoxide dismutase (SOD), malondialdehyde (MDA), glutathione peroxidase (GSH-PX) and the production of inflammatory cytokines interleukin-1β (IL-1β), tumour necrosis factor-α (TNF-α), and interleukin-6 (IL-6) to evaluate the effect of yam glycoprotein on lung tissue changes. We examined the protein expression of TLR4, ASC, NF-κBp65, p-NF-κBp65, Caspase-1, IκB, NLRP3, p-IκB, and β-actin by western blot analysis. Immunohistochemical analyses of NLRP3 and p-p65 in lung tissue were carried out to assess the mechanism of glycoprotein action. This result suggests that glycoprotein markedly depressed LPS-induced lung W/D ratio, MPO activity, MDA content SOD and GSH-Px depletion, and the contents of inflammatory cytokines IL-1β, IL-6, and TNF-α. Moreover, glycoprotein blocked TLR4/NF-κBp65 signaling activation and NLRP3inflammasome expression in LPS-induced ALI mice. As this particular study shows, glycoprotein has a safeguarding effects on LPS-induced ALI mice, possibly via activating NLRP3inflammasome and TLR4/NF-κB signaling pathways.     

A supercritical CO₂ extract from seabuckthorn leaves inhibits pro-inflammatory mediators via inhibition of mitogen activated protein kinase p38 and transcription factor nuclear factor-κB

In the present study, we have demonstrated the anti-inflammatory properties of supercritical CO₂ extract of seabuckthorn leaves (SCE) on mouse alveolar macrophage cell line (MH-S), human peripheral blood mononuclear cells (hPBMCs) in-vitro and in-vivo. Treatment of MH-S cells with SCE (0.5–100 μg/ml) significantly inhibited lipopolysaccharide (LPS)-stimulated nitric oxide (NO) production. It also inhibited the release of LPS-induced pro-inflammatory cytokines IL-6 and TNF-α, which was further confirmed by suppression of LPS induced TNF-α in hPBMCs by ELISPOT assay. In addition, western blot analysis demonstrated that SCE decreased LPS-induced inducible nitric-oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) protein expression in MH-S cells. Furthermore, SCE treatment also reduced nuclear factor-κB (NF-κB) translocation in nucleus induced by LPS in MH-S cells. To elucidate the molecular mechanism for inhibition of pro-inflammatory mediators by SCE (100 μg/ml), we further studied the effect of SCE on LPS-induced p38 mitogen-activated protein kinase (MAPK). It was observed that the phosphorylation of p38 MAPK in LPS-stimulated MH-S cells was significantly inhibited by SCE, which was further proven by suppression of LPS induced CD40 expression. The in-vivo model of AIA mice also showed a significant reduction in the inflammation of paw edema. These data collectively suggest that SCE suppressed the LPS-induced production of NO, IL-6, and TNF-α and expression of CD40, iNOS and COX-2 proteins by inhibiting NF-κB activation and phosphorylation of p38 MAPK. Hence, the SCE has potent anti-inflammatory activity and might be useful in chronic inflammatory diseases.     

Genipin alleviates LPS-induced acute lung injury by inhibiting NF-κB and NLRP3 signaling pathways

Genipin has been reported to have anti-inflammatory effect. However, its role on lipopolysaccharide (LPS)-induced acute lung injury (ALI) has not been explored. This study aimed to evaluate the effect of genipin on murine model of acute lung injury induced by LPS. The mice were treated with genipin 1 h before LPS administration. 12 h later, the myeloperoxidase (MPO) in lung tissues and lung wet/dry ratio were detected. The levels of TNF-α, IL-1β and IL-6 in bronchoalveolar lavage fluid (BALF) were measured by ELISA. Apart from this, we use western blot to detect the protein expression in the NF-κB and NLRP3 signaling pathways. The results showed that the treatment of genipin markedly attenuated the lung wet/dry ratio and the MPO activity. Moreover, it also inhibited the levels of TNF-α, IL-1β, IL-6 in the BALF. In addition, genipin significantly inhibited LPS-induced NF-κB and NLRP3 activation. In conclusion, these results demonstrate that genipin protected against LPS-induced ALI through inhibiting NF-κB and NLRP3 signaling pathways.     

Naringin attenuates acute lung injury in LPS-treated mice by inhibiting NF-κB pathway

Naringin has been reported as an effective anti-inflammatory compound. We previously showed that naringin had antitussive effect on experimentally induced cough in guinea pigs. However, the effects and mechanism of naringin on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice are not fully understood. In this study, our aim was to evaluate the anti-inflammatory activities of naringin on LPS-induced ALI in mice and clarify its underlying mechanisms of action. We found that in vivo pretreatment with naringin markedly decreased the lung wet weight to dry weight ratio, and led to significant attenuation of LPS-induced evident lung histopathological changes. Meanwhile, naringin significantly reduced bronchoalveolar lavage fluid (BALF) total cell and neutrophil (PMN) counts after LPS challenge. Furthermore, naringin inhibited myeloperoxidase (MPO: a marker enzyme of neutrophil granule) and inducible nitric oxide synthase (iNOS) activities in lung tissue and alleviated LPS-induced tumor neurosis factor-α (TNF-α) secretion in BALF in a dose-dependent manner. Additionally, Western blotting showed that naringin efficiently blunt NF-κB activation by inhibiting the degradation of I?B-α and the translocation of p65. Taken together, these results suggest that naringin shows anti-inflammatory effects through inhibiting lung edema, MPO and iNOS activities, TNF-α secretion and pulmonary neutrophil infiltration by blockade of NF-κB in LPS-induced ALI.