异丙酚对内毒素诱导人单核细胞系THP-1细胞TREM-1表达的影响

【摘要】目的 探讨异丙酚对内毒素诱导人单核细胞系THP-1细胞髓样细胞触发性受体-1（TREM-1）表达的影响。方法 培养THP-1细胞,分成7组,分别对应：Control组,单纯无血清培养基培养;内毒素（LPS）组,单纯LPS100μg/L刺激;Pro组,单纯加入异丙酚100μmol/L;P1组,LPS+异丙12.5μmol/L;P2组,LPS+异丙酚25μmol/L;P3组,LPS+异丙酚50μmol/L;P4组,LPS+异丙酚100μmol/L。观察16h后收集细胞培养上清液采用ELISA测定肿瘤坏死因子（TNF）-α水平;收集细胞采用流式细胞术检测TREM-1蛋白表达水平;收集细胞采用实时定量PCR检测TREM-1mRNA表达水平。结果 与LPS组相比,P3组与P4组的细胞表面TREM-1蛋白表达水平明显增高（P<0.05）,细胞上清液中TNF-α水平明显下降（P<0.05）;与Control组比较,LPS组TREM-1mRNA表达明显增加（P<0.05）;与LPS组比较,P4组细胞TREM-1mRNA表达水平降低（P<0.05）。结论 异丙酚可使LPS诱导的THP-1细胞表面TREM-1蛋白表达水平增加,细胞TNF-α的释放减少,TREM-1mRNA的表达量下降。     

褪黑素对内毒素血症大鼠血清炎性因子的影响

目的探讨褪黑素(MT)对脂多糖(LPS)诱导的内毒素血症大鼠炎性因子肿瘤坏死因子-α(TNF-α)、白介素-6(IL-6)和抗炎因子IL-10表达的影响。方法雄性SD大鼠48只,分为溶剂对照组、LPS组、LPS+MT组、MT组,每组12只。检测各组大鼠血清超氧化物歧化酶(SOD)和丙二醛(MDA)的含量;应用酶联免疫吸附法(ELISA)检测血清TNF-α、IL-6和IL-10含量。结果 LPS+MT组的血清SOD活性较LPS组明显增高(P<0.01),MDA含量较LPS组明显降低(P<0.01);LPS组大鼠血清TNF-α,IL-6含量明显上升,与对照组比较差异有统计学意义(P<0.01),而给予LPS前后应用MT干预治疗,可显著降低血清TNF-α、IL-6含量,与同时间点LPS组比较均差异有统计学意义(P<0.01)。结论 MT可以降低内毒素血症大鼠血清炎性因子水平。     

TNF-αsiRNA表达载体的构建及其对胶原性关节炎大鼠TNF-α及IL-1的影响

目的观察肿瘤坏死因子（TNF）-α的小干扰RNA（siRNA）真核表达载体对胶原性关节炎（CIA）大鼠的治疗作用。方法构建TNF-α的siRNA真核表达载体并注射CIA大鼠,随机分为模型组、空载体组、TNF-α-siRNA1组和TNF-α-siRNA2组,每组6只,各组分别尾静脉注射磷酸盐缓冲液（PBS）、pGFP-V-RS空载体、TNF-α-siRNA1真核表达载体和TNF-α-siRNA2真核表达载体。另设6只未造CIA模型只注射PBS的大鼠为空白组。于注射后1、5、9和13 d采血,ELISA检测血清中IL-1的变化;注射后13 d处死大鼠,RT-PCR检测TNF-αmRNA的表达水平。结果注射第1、5、9和13天模型组大鼠血清中IL-1的表达水平高于空白组（P<0.05）,注射第1、5和9天TNF-α-siRNA1组和TNF-α-siRNA2组IL-1的表达水平低于模型组和空载体组（P<0.05）;注射后第13天模型组大鼠全血中TNF-αmRNA的表达水平明显高于空白组（P<0.05）,TNF-α-siRNA1组和TNF-α-siRNA2组mRNA表达水平低于模型组和空载体组（P<0.05）。结论 TNF-α的特异性siRNA能抑制TNF-αmRNA和IL-1的表达水平,从而为类风湿关节炎的基因治疗提供实验依据。     

透明质酸钠对兔心脏术后心包粘连炎性因子影响

目的观察透明质酸钠在兔心脏术后心包粘连对血清中肿瘤坏死因子α(TNF-α)、白细胞介素-1β(IL-1β)、白细胞介素-6(IL-6)含量的影响。方法采用兔心脏术后心包粘连模型。用药各组分别给予:①术后心包腔灌注透明质酸钠(5mg/只),每日1次,共7天;②;模型组及假手术组给予等容积的生理盐水。各组动物于术后6h、24h、3d、5d共4个时间点静脉取血,测定IL-1β、IL-6、TNF-α炎性细胞因子的含量。结果SHA组IL-1β、IL-6、TNF-α含量与Model组相比均在高峰期明显降低(P<0.01)。结论透明质酸钠对兔心脏术后心包粘连的形成有干预作用;其干预作用可能与降低血清中IL-1β、IL-6、TNF-α的含量有关。     

黄金牡丹合剂对内毒素血症小鼠细胞因子的影响

目的:研究黄金牡丹合剂(HJM)对内毒素血症小鼠细胞因子的影响。方法:腹腔注射内毒素(LPS)以复制小鼠内毒素血症模型。实验分为空白(等容无菌水)、模型对照(等容无菌水)、地塞米松(DEXA,0.80mL.kg-1)和HJM高、中、低剂量(1.00、0.50、0.25mL.kg-1)组,灌胃给药,每天2次,连续3d,观察以上6组小鼠72h死亡率。采用相同给药方式,以酶联免疫吸附法(ELISA)测定复制模型后空白、模型对照、DEXA和HJM中剂量组6、12、18、24、48、72h血清肿瘤坏死因子α(TNF-α)、白细胞介素(IL)-4、IL-6含量。结果:与模型对照组比较,HJM中剂量组死亡率显著降低(P<0.01)。HJM组TNF-α、IL-6含量显著降低(P<0.01或P<0.05),IL-4含量显著升高(P<0.05)。结论:HJM能显著降低内毒素血症小鼠死亡率,其机制可能与降低血清中TNF-α、IL-6的含量,促进IL-4释放,抑制过度炎症反应有关。     

血必净对急性百草枯中毒大鼠炎性因子影响的实验研究

目的 观察血必净对百草枯急性中毒大鼠炎性因子的抑制作用.方法 72只SD大鼠随机分为对照组、中毒组和血必净组,分别在给药后6h、2h、72h三个时间点,每个时间点每组8只大鼠,中毒组和血必净组一次性以120mg/kg百草枯灌胃,2h后血必净组腹腔注射血必净10ml/kg,对照组和中毒组腹腔注射等体积0.9%氯化钠注射液,1次/d.于给药后6h、24h、72h取大鼠眼眶血,用酶联免疫(ELISA)检测血清肿瘤坏死因子-α(TNF-α)、白介素-1β(IL-1β)和IL-2.结果 给药后6h中毒组血清TNF-α、IL-1β和IL-2较其他组明显升高(P<0.05),而血必净组较中毒组明显降低(P<0.05);给药后24h中毒组血清TNF-α、和IL-1β较其他组明显升高(P<0.05),而血必净组TNF-α、IL-1β较中毒组明显降低(P<0.05);给药后72h中毒组血清TNF-α仍较其他组明显升高(P<0.05),血必净组TNF-α较中毒组明显降低(P<0.05),而且IL-1β和IL-2已降至对照组水平(P0.05).结论 血必净可以明显抑制急性百草枯中毒大鼠血清TNF-α、IL-1β和IL-2的释放,对急性百草枯中毒大鼠炎性反应具有一定的抑制作用.     

慢性牙周炎患者血清炎性因子水平的变化

目的探讨慢性牙周炎患者血清IL-8、IL-6、IL-1β和TNF-α的变化规律。方法应用酶联免疫吸附法（ELISA）对60例慢性牙周炎患者治疗前后进行血清IL．8、IL-6、IL-1β和TNF-α水平检测,并与同期健康体检者60例作比较。结果慢性牙周炎患者治疗前血清IL-8、IL-6、IL-1β和TNF—Q水平分别为（836．5±23．7）（、7．2±1．0）、（1156．8±58．5）和（76．5±7．2）ng／L,均显著高于健康体检组（409．8±22．5）、（1．9±1．0）、（582．4±38．6）、（55．8±6．3）（均P〈0．01）;治疗3个月后,IL-8、IL-6、IL-1β和TNF-α水平分别为（443．6±16．6）、（2．2±0．9）、（605．4±42．2）和（58．2±6．5）ng/L,与健康体检者比较差异无统计学意义（P〉0．05）。结论在慢性牙周炎的发生发展中,IL-8、IL-6、IL-1β和TNF-α发挥了重要的致炎作用,其水平的变化可从一定程度上反映疾病的情况,为预防和指导临床用药提供参考。     

糖皮质激素对内毒素耐受的影响

目的应用地塞米松(dexamethasone,Dex)干预小鼠内毒素耐受的形成,研究糖皮质激素对内毒素耐受的影响。方法以昆明鼠为实验对象进行分组,ⅠA组为健康对照组,ⅠB组为单次直接致死剂量脂多糖(lipopolysaccharide,LPS)(2LD50=8 mg/kg)对照组,Ⅱ组为标准内毒素耐受组,ⅢA组为初始LPS刺激前高剂量Dex(10 mg/kg)干预组,ⅢB组为终末致死量LPS前高剂量Dex干预组,ⅣA组为初始LPS刺激前低剂量Dex(1mg/kg)干预组,ⅣB组为终末致死量LPS前低剂量Dex干预组。完成实验处置后3 h取血标本,应用ELISA方法检测血清TNF-α和IL-10水平。结果①ⅠA组TNF-α、IL-10水平极低,ⅠB组TNF-α、IL-10水平较ⅠA组显著增高(P<0.05,P<0.01),Ⅱ组TNF-α、IL-10水平较ⅠB组显著下降(P<0.05,P<0.01),但仍高于ⅠA组。②各Dex干预组TNF-α水平与Ⅱ组比较:ⅢA、ⅣA组TNF-α水平与Ⅱ组TNF-α水平差异无统计学意义(P>0.05),ⅢB、ⅣB组TNF-α水平低于Ⅱ组,差异有统计学意义(P<0.05)。③各Dex干预组IL-10水平与Ⅱ组比较:ⅢA、ⅣA组IL-10水平高于Ⅱ组,差异有统计学意义(P<0.05),ⅢB、ⅣB组IL-10水平与Ⅱ组比较差异无统计学意义(P>0.05)。结论①LPS刺激可导致小鼠体内TNF-α水平、IL-10水平升高。内毒素耐受时,小鼠体内TNF-α、IL-10水平升高的程度明显降低。②终末LPS前一定时间内予以Dex干预可以促进内毒素耐受的形成,Dex剂量过高可能不会带来更多受益。③IL-10对内毒素耐受的形成可能不具有决定作用。     

山药、银杏叶提取物对体外oxLDL诱导单核巨噬细胞炎性因子释放的抑制作用研究

目的:研究山蒟提取物(EPH)、银杏叶提取物(EGB)对氧化低密度脂蛋白(oxLDL)诱导单核巨噬细胞U937细胞炎性因子白细胞介素-1β(IL-1β)、肿瘤坏死因子-α(TNF-α)释放的抑制作用。方法:以80 mg·L~(-1)的oxLDL刺激U937细胞,通过酶联免疫吸附法(ELISA)测定各时间点IL-1β、TNF-α释放量,绘制释放曲线,并考察EPH、EGB对其释放的影响。结果: oxLDL刺激U937细胞释放IL-1β、TNF-α;在24 h时,IL-1β与TNF-α释放量均极显著性增加(P<0.01),EPH、EGB均在100、10 mg·L~(-1)浓度下对IL-1β有显著性抑制作用(P<0.05);EPH在100、10 mg·L~(-1)浓度和EGB在100 mg·L~(-1)浓度下均对TNF-α释放有显著性抑制作用。结论:oxLDL(80 mg·L~(-1))在体外可显著诱导U937细胞释放炎性因子IL-1β、TNF-α, EGB、EPH对炎性因子释放有抑制作用,且在100 mg·L~(-1)浓度下EPH的体外抗炎作用更为显著。     

免疫球蛋白静脉滴注对重症手足口病患儿血清炎性因子水平的影响

目的 研究静脉滴注免疫球蛋白对重症手足口病患儿血清炎性因子水平的影响.方法 将2009年4至6月收治的手足口病患儿40例,根据病情分为普通病例组(20例)和重症病例组(20例),单纯隐睾或斜疝儿童20例为对照组.20例手足口病重症病例组出现神经系统受累,但无心肺功能损害.重症病例组入院第1天及第2天分别予静脉滴注免疫球蛋白1g/(kg·d),用酶联免疫吸附试验分别检测血清肿瘤坏死因子(TNF)-α、白细胞介素(IL)-6和IL-10含量.结果 普通病例组、重症病例组治疗前,重症病例组治疗后及对照组TNF-α含量分别为(71.70±12.35)、(152.20±59.99)、(150.95±61.77)、(36.65±10.46)ng/L,IL-6含量分别为(14.50±3.83)、(59.35±13.27)、(25.30±7.58)、(16.40±6.63) ng/L,IL-10 含量分别为(9.82±2.20)、(38.19±8.54)、(23.30±5.21)、(9.32±2.08)ng/L.重症病例组血清TNF-α、IL-6和IL-10含量均高于普通病例组和对照组(P＜0.01),静脉滴注免疫球蛋白治疗后重症病例组血清IL-6和IL-10明显降低(P＜0.01),但血清TNF-α水平治疗前后差异无统计学意义(P＞0.05).普通病例组血清TNF-α含量高于对照组(P＜0.01),普通病例组血清IL-6和IL-10含量与对照组比较,差异无统计学意义(P＞0.05).结论 静脉滴注免疫球蛋白可明显降低重症手足口病患儿血清IL-6和IL-10水平.     

髓样细胞表达的触发受体-1分子的功能与信号转导机制研究进展

髓样细胞表达的触发受体-1（TREM-1）是新近发现的一种与炎症级联放大密切相关的免疫球蛋白超家族成员,主要表达于中性粒细胞及成熟的单核细胞、巨噬细胞表面。多种细菌性成分以及创伤等能使其表达增加,并能与其位于血小板表面的内源性配体一起激活该受体,从而激发炎症因子、趋化因子的产生及中性粒细胞的脱颗粒、呼吸暴发和吞噬作用。TREM-1分子在脂多糖（LPS）所致的内毒素血症中尤其具有显著放大炎症反应的作用,近年来对其信号转导机制的研究取得了大量新的进展。另外,TREM-1与Toll样受体-4（TLR4）在LPS所致炎症反应的放大中存在协同作用,但具体机制目前还不太明确。血浆中还存在TREM-1的可溶性形式,由金属蛋白酶使膜上TREM-1分子外功能区脱落而形成,可作为炎症性疾病早期诊断和预后判断的新指标。     

包含CDR1在内的小鼠TREM-1分子保守区基因的克隆和原核表达

目的为研究包含CDR1在内的小鼠TREM—1分子保守区功能及TREM—1分子的活化方式奠定基础。方法从正常成年昆明小鼠组织中提取细胞基因组DNA，利用PCR技术扩增出包含CDRl在内的小鼠TREM—1分子保守区基因片断。构建PET-30a（＋）-CDR1原核表达载体，并转化到BL21（DE3）plysS大肠杆菌中通过IPTG诱导表达，将表达产物进行Tricine—SDS—PAGE电泳分析和Western blot检测分析。结果从小鼠组织中成功获得包含CDRl在内的小鼠TREM—1分子保守区的目的基因片断并定向克隆到原核表达载体中。克隆菌表达的蛋白电泳分析见一新的条带，相对分子质量在1．0×10^4左右，WestenBlot检测显示其有与Anti—His单克隆抗体特异性结合的能力。结论成功构建了包含CDR1在内的小鼠TREM—1保守区基因的原核表达载体，并在BL21（DE3）plysS大肠杆菌中稳定大量表达。     

Protection against lipopolysaccharide-induced sepsis and inhibition of interleukin-1beta and prostaglandin E2 synthesis by silymarin

Silymarin is known to have hepatoprotective and anticarcinogenic effects. Recently, anti-inflammatory effect of silymarin is attracting an increasing attention, but the mechanism of this effect is not fully understood. Here, we report that silymarin protected mice against lipopolysaccharide (LPS)-induced sepsis. In this model of sepsis, silymarin improved the rate of survival of LPS-treated mice from 6 to 38%. To further investigate the mechanism responsible for anti-septic effect of silymarin, we examined the inhibitory effect of silymarin on interleukin-1beta (IL-1beta) and prostaglandin E2 (PGE2) production in macrophages. Silymarin dose-dependently suppressed the LPS-induced production of IL-1beta and PGE2 in isolated mouse peritoneal macrophages and RAW 264.7 cells. Consistent with these results, the mRNA expression of IL-1beta and cyclooxygenase-2 was also completely blocked by silymarin in LPS-stimulated RAW 264.7 cells. Moreover, the LPS-induced DNA binding activity of nuclear factor-kappaB/Rel was also inhibited by silymarin in RAW 264.7 cells. Taken together, these results demonstrate that silymarin has a protective effect against endotoxin-induced sepsis, and suggest that this is mediated, at least in part, by the inhibitory effect of silymarin on the production of IL-1beta and PGE2.     

1, 25-Dihydroxyvitamin D3 activates Apelin/APJ system and inhibits the production of adhesion molecules and inflammatory mediators in LPS-activated RAW264.7 cells

Background1, 25-Dihydroxyvitamin D3 (1, 25(OH)₂D₃), an active form of vitamin D3, plays a crucial role in the mitigation of inflammation damage. Recent studies have revealed that apelin and its receptor (apelin/APJ system) could significantly ameliorate LPS-induced inflammation-response. This investigation aimed to appraise the effects of 1, 25(OH)₂D₃ on the apelin/APJ system and production of adhesion molecules and inflammatory mediators in LPS–activated RAW264.7 macrophage cells.MethodsMurine RAW264.7 cells were pretreated with 1, 25(OH)₂D₃, followed stimulation with LPS (1 μg/mL) for 24 h. The effect of 1, 25(OH)₂D₃ on LPS-induced cell injury was determined by MTT assay, whereas, enzyme-linked immunosorbent assay (ELISA), qPCR and western blotting were used to evaluate cytokine production and apelin/APJ system expression. Intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) protein expression were measured by flow cytometry.ResultsThe levels of IL-1β, IL-6, and TNF-α cytokines were significantly increased by incubation with LPS. LPS also increased the protein expression of adhesion molecules, including VCAM-1 and ICAM-1. However, pretreatment with 1, 25(OH)₂D₃ markedly inhibited LPS-induced production of inflammatory cytokines and adhesion molecules. Moreover, we found that 1, 25(OH)₂D₃ could induced the apelin/APJ system expression. Further experiments demonstrated the significant increase of apelin/APJ system expression at both the protein and mRNA levels in LPS-activated cells when pretreated with 1, 25(OH)₂D₃.ConclusionTaken together, our results indicated that 1, 25(OH)₂D₃ confers an anti-inflammatory effect through a likely mechanism involving a reduction in pro-inflammatory mediators and adhesion molecules via up-regulation of the apelin/APJ system in RAW264.7 cells.     

Preventive effect of Coptis chinensis and berberine on intestinal injury in rats challenged with lipopolysaccharides

Coptis chinensis has been used in traditional Chinese medicine to treat inflammatory symptoms. Berberine is the main alkaloid compound of C. chinensis. This study utilized a typical lipopolysaccharide (LPS) injured model to investigate the effects of C. chinensis aqueous extract (CCAE) and berberine (major active ingredient in CCAE) in the gut-derived sepsis. In rats, pretreatment with different doses of berberine (30 or 120 mg/kg bw, i.g.; BBR30 or BBR120) or CCAE (containing 9.9% berberine; 300 mg/kg bw, i.g.; CCAE300) prior to the administration of LPS (20 mg/kg bw, i.p.) significantly suppressed the increased tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and nitrite oxide (NO) in plasma as well as the activation of toll-like receptor 4 (TLR4) and nuclear factor-κB (NF-κB) in ileum. In addition, CCAE300 and BBR30 markedly elevated the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px); significantly prevented the increased malondialdehyde (MDA), NO and villi injury in ileum compared with the negative control. Collectively, CCAE300 and BBR30 reduced the LPS-induced intestinal damage by elevating the activities of SOD and GSH-Px and by suppressing the activation of TLR4 and NF-κB in ileum. These results indicate that CCAE and berberine are promising agents for preventing sepsis and its complications.     

Effects of a selective cyclooxygenase-2 inhibitor, celecoxib, on bone resorption and osteoclastogenesis in vitro

The effects of an important new anti-inflammatory agent, the selective cyclooxygenase-2 inhibitor celecoxib, on bone resorption and osteoclastogenesis elicited by the inflammatory cytokines interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha), the endotoxin lipopolysaccharide (LPS), and the systemic hormones 1alpha,25-dihydroxyvitamin D(3) and parathyroid hormone were examined in vitro. Bone resorption was evaluated by measuring calcium released into the culture medium in a neonatal mouse calvarial bone organ culture. Osteoclastogenesis was evaluated by measuring tartrate-resistant acid phosphatase activity in the cells in cocultures of bone marrow cells and osteoblastic cells and in macrophage-colony-stimulating factor-dependent bone marrow cell cultures. Celecoxib (0.1 microM) completely inhibited the calcium release induced by IL-1beta, TNF-alpha, and LPS. The resorptive effect of 1alpha,25-dihydroxyvitamin D(3) was inhibited partially by celecoxib. In contrast, celecoxib did not inhibit the calcium release elicited by parathyroid hormone or prostaglandin E(2). Celecoxib (0.1 microM) also markedly inhibited osteoclastogenesis induced by these stimulators of bone resorption except for PGE(2) in the coculture system, whereas it failed to inhibit osteoclastogenesis in macrophage-colony-stimulating factor-dependent bone marrow cell cultures. These results indicate that, under certain conditions, cyclooxygenase-2-dependent prostaglandin synthesis is critical for the bone resorption induced by IL-1beta, TNF-alpha, and LPS, and for the osteoclastogenesis induced by these pro-inflammatory molecules and calciotropic hormones. The prevention of prostaglandin synthesis by inflammatory cytokines in bone cells could contribute to the efficacy of celecoxib in preventing bone loss in rheumatoid arthritis.     

Preventing cleavage of Mer promotes efferocytosis and suppresses acute lung injury in bleomycin treated mice

Mer receptor tyrosine kinase (Mer) regulates macrophage activation and promotes apoptotic cell clearance. Mer activation is regulated through proteolytic cleavage of the extracellular domain. To determine if membrane-bound Mer is cleaved during bleomycin-induced lung injury, and, if so, how preventing the cleavage of Mer enhances apoptotic cell uptake and down-regulates pulmonary immune responses. During bleomycin-induced acute lung injury in mice, membrane-bound Mer expression decreased, but production of soluble Mer and activity as well as expression of disintegrin and metalloproteinase 17 (ADAM17) were enhanced . Treatment with the ADAM inhibitor TAPI-0 restored Mer expression and diminished soluble Mer production. Furthermore, TAPI-0 increased Mer activation in alveolar macrophages and lung tissue resulting in enhanced apoptotic cell clearance in vivo and ex vivo by alveolar macrophages. Suppression of bleomycin-induced pro-inflammatory mediators, but enhancement of hepatocyte growth factor induction were seen after TAPI-0 treatment. Additional bleomycin-induced inflammatory responses reduced by TAPI-0 treatment included inflammatory cell recruitment into the lungs, levels of total protein and lactate dehydrogenase activity in bronchoalveolar lavage fluid, as well as caspase-3 and caspase-9 activity and alveolar epithelial cell apoptosis in lung tissue. Importantly, the effects of TAPI-0 on bleomycin-induced inflammation and apoptosis were reversed by coadministration of specific Mer-neutralizing antibodies. These findings suggest that restored membrane-bound Mer expression by TAPI-0 treatment may help resolve lung inflammation and apoptosis after bleomycin treatment.     

Brazilin selectively disrupts proximal IL-1 receptor signaling complex formation by targeting an IKK-upstream signaling components

The ligation of interleukin-1 receptor (IL-1R) or tumor necrosis factor receptor 1 (TNFR1) induces the recruitment of adaptor proteins and their concomitant ubiquitination to the proximal receptor signaling complex, respectively. Such are upstream signaling events of IKK that play essential roles in NF-κB activation. Thus, the discovery of a substance that would modulate the recruitment of key proximal signaling elements at the upstream level of IKK has been impending in this field of study. Here, we propose that brazilin, an active compound of Caesalpinia sappan L. (Leguminosae), is a potent NF-κB inhibitor that selectively disrupts the formation of the upstream IL-1R signaling complex. Analysis of upstream signaling events revealed that brazilin markedly abolished the IL-1β-induced polyubiquitination of IRAK1 and its interaction with IKK-γ counterpart. Notably, pretreatment of brazilin drastically interfered the recruitment of the receptor-proximal signaling components including IRAK1/4 and TRAF6 onto MyD88 in IL-1R-triggerd NF-κB activation. Interestingly, brazilin did not affect the TNF-induced RIP1 ubiquitination and the recruitment of RIP1 and TRAF2 to TNFR1, suggesting that brazilin is effective in selectively suppressing the proximal signaling complex formation of IL-1R, but not that of TNFR1. Moreover, our findings suggest that such a disruption of IL-1R-proximal complex formation by brazilin is not mediated by affecting the heterodimerization of IL-1R and IL-1RAcP. Taken together, the results suggest that the anti-IKK activity of brazilin is induced by targeting IKK upstream signaling components and subsequently disrupting proximal IL-1 receptor signaling complex formation.