Raf inhibition protects cortical cells against beta-amyloid toxicity

Alzheimer's disease (AD) is the main cause of dementia in the elderly. The discovery of new targets of therapeutic intervention is fundamental to the development of new drugs against AD pathology. Upregulation of cRaf-1 has been found post-mortem in the brains of AD patients. cRaf-1 is a cytosolic protein kinase that regulates neuronal survival and senescence. In this study, we investigated cRaf-1 in the brains of aged APPswe mice presenting AD-like pathology and whether Raf inhibitors protected cultured cortical cells against amyloid beta toxicity (Abeta). We found a dysregulation of cRaf-1 in the cortex of APPswe mice, which showed a 147% increase in the active form phosphorylated at serine 338 and a 40% decrease in the levels of the inactive form of cRaf-1, phospho-cRaf-1[Ser259]. Furthermore, treatment of primary cortical neurons with the cRaf-1 inhibitors, GW5074 or ZM336372, and the nuclear factor kappa B (NFkappaB) inhibitor SN50, protected cortical neurons against Abeta toxicity. Since Raf stimulates NFkappaB, we studied the effect of Raf inhibition on its activation by studying changes in NFkappaB phosphorylation at serine 276. Our results suggest that Raf inhibition with GW5074 is neuroprotective against Abeta toxicity through a mechanism that involves NFkappaB inhibition.     

Suppression of nuclear factor kappa B ameliorates astrogliosis but not amyloid burden in APPswe/PS1dE9 mice

Neuroinflammation has been linked to the pathologies of Alzheimer's disease (AD), however, its effects on beta-amyloid (Aβ) burden are unclear. This study investigated the role of nuclear factor kappa B (NF-κB) in regulating neuroinflammation and Aβ deposition in a transgenic mouse model of AD. The APPswe/PS1dE9 mice and their wild-type controls received either the NF-κB inhibitor pyrrolidine dithiocarbamate (PDTC, i.p. 50 mg/kg daily) or saline starting at 7 months of age for 5 months. Expression of cyclooxygenase-2 (COX-2), tissue necrosis factor alpha (TNFα) precursor protein and microtubule-associated protein 2 was determined, and astrogliosis was assessed. Hippocampal and cortical levels of Aβ_1-40 and Aβ_1-42 were measured using ELISA. PDTC treatment effectively suppressed NF-κB signaling in APPswe/PS1dE9 mice as evidenced by the abolishment of COX-2 and TNFα induction. Inhibition of NF-κB further attenuated astrogliosis in the transgenic AD mice, yet markedly increased cerebral Aβ_1-42 burden. Our findings suggest that NF-κB can mediate induction of COX-2, TNFα and astrogliosis in APPswe/PS1dE9 mice. Additionally, these results support the idea that neuroinflammation contributes to the clearance of Aβ.     

Voluntary Running Attenuates Memory Loss,Decreases Neuropathological Changes and Induces Neurogenesis in a Mouse Model of Alzheimer's Disease

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by loss of memory and cognitive abilities, and the appearance of amyloid plaques composed of the amyloid‐β peptide (Aβ) and neurofibrillary tangles formed of tau protein. It has been suggested that exercise might ameliorate the disease; here, we evaluated the effect of voluntary running on several aspects of AD including amyloid deposition, tau phosphorylation, inflammatory reaction, neurogenesis and spatial memory in the double transgenic APPswe/PS1ΔE9 mouse model of AD. We report that voluntary wheel running for 10 weeks decreased Aβ burden, Thioflavin‐S‐positive plaques and Aβ oligomers in the hippocampus. In addition, runner APPswe/PS1ΔE9 mice showed fewer phosphorylated tau protein and decreased astrogliosis evidenced by lower staining of GFAP. Further, runner APPswe/PS1ΔE9 mice showed increased number of neurons in the hippocampus and exhibited increased cell proliferation and generation of cells positive for the immature neuronal protein doublecortin, indicating that running increased neurogenesis. Finally, runner APPswe/PS1ΔE9 mice showed improved spatial memory performance in the Morris water maze. Altogether, our findings indicate that in APPswe/PS1ΔE9 mice, voluntary running reduced all the neuropathological hallmarks of AD studied, reduced neuronal loss, increased hippocampal neurogenesis and reduced spatial memory loss. These findings support that voluntary exercise might have therapeutic value on AD.     

自主跑轮运动对阿尔兹海默病模型小鼠认知、情绪以及杏仁核炎性因子表达的影响

目的:探讨自主跑轮运动对阿尔茨海默病(Alzheimer’s disease,AD)模型小鼠空间记忆能力、情绪,以及小鼠脑内杏仁核NF-κB、TNF-α和IL-10表达的影响。方法:将18只3月龄的雄性昆明小鼠随机分为:二甲基亚砜(DMSO)对照组(n=6)和AD模型组(n=12)。AD模型组小鼠通过侧脑室内注射Aβ_(1-42)进行造模,造模一周后采用Y迷宫新异臂实验验证造模是否成功,并将造模成功的AD小鼠随机分成AD安静组(n=6)和AD运动组(n=6)。AD运动组进行为期6周的自主跑轮运动,AD安静组与DMSO对照组在同等环境下正常饲养6周。运动结束后,采用Y迷宫新异臂实验、高架十字迷宫实验、强迫游泳实验分别检测三组小鼠的空间记忆能力、焦虑、抑郁情绪,并统计分析。行为学实验结束后,用蛋白免疫印迹(Western Blot)实验检测三组小鼠杏仁核NF-κB、TNF-α和IL-10的表达变化。结果:(1)Y迷宫新异臂实验结果显示:造模一周后,AD模型组在新异臂中停留的时间(88.2 s±8.19 s)显著低于DMSO对照组(135.48 s±8.63 s,P﹤0.01);运动结束后,AD运动组在新异臂中停留的时间是AD安静组的1.7倍(P﹤0.01),但与DMSO对照组无统计学差异。(2)高架十字迷宫实验结果显示:AD运动组在开放臂中停留的时间较AD安静组显著升高(P﹤0.01),但与DMSO对照组无统计学差异。(3)强迫游泳实验结果显示:AD运动组的不动时间(88.64 s±5.23 s)明显低于AD安静组(236.13s±7.04 s,P﹤0.001),但与DMSO对照组无统计学差异。(4)蛋白免疫印迹结果显示:促炎因子TNF-α和NF-κB在AD安静组的表达均显著高于AD运动组和DMSO对照组(P﹤0.05),而抗炎因子IL-10的表达与之相反,低于AD运动组和DMSO组(P﹤0.05),各检测因子在AD运动组和DMSO组的表达无明显差异。结论:自主跑轮运动可有效改善AD模型小鼠的空间记忆以及焦虑抑郁情绪,并且改善杏仁核内炎性细胞因子的表达,从而发挥其脑保护作用。     

Anti-inflammatory activity of ethylacetate fraction of Cliona celata

We evaluated the ability of the ethylacetate fraction of marine sponge, Cliona celata (ECC), harvested from Korean seaside to regulate the expression of inducible nitric oxide synthase (iNOS) in lipopolysaccharide (LPS)-stimulated murine macrophage-like RAW264.7 cells. ECC dose-dependently inhibited both the expression of iNOS protein and mRNA, resulting in decreased production of nitric oxide (NO), with an IC(50) of 80.5 μg/mL. To investigate action mechanism by which ECC inhibits NO production and iNOS expression, we examined the activation of IκB in LPS-stimulated RAW264.7 cells. ECC clearly inhibited translocation of nuclear factor-κB (NF-κB) p65 subunits from cytosol to nucleus, which correlated with its inhibitory effects on IκB-α phosphorylation and degradation. Furthermore, ECC potently suppressed both the reporter gene expression and DNA-binding activity of NF-κB, which was associated with decreased p65 protein levels in the nucleus. Here, we show for the first time that ECC inhibits NF-κB activation through the inhibition of IκB degradation.     

Callosal agenesis and absence of primary visual cortex induced by prenatal X rays impair navigation's strategy and learning in tasks involving visuo-spatial working but not reference memory in mice

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by cognitive and memory deterioration. Production and accumulation of β-amyloid peptide (Aβ) is central to the pathogenesis of AD. Recent studies have demonstrated that PKA/CREB-dependent signaling pathway and long-term potentiation are inhibited by sublethal concentrations of Aβ_1–42 in cultured hippocampus neurons. Here, we examined the effects of nobiletin on the Aβ-induced inhibition of CREB phosphorylation in cultured rat hippocampus neurons. A sublethal concentration of Aβ_1–42 or Aβ_1–40 decreased glutamate-induced CREB phosphorylation, whereas pretreatment with nobiletin reversed the Aβ-induced decrease in CREB phosphorylation. The effects of nobiletin on impairment of learning ability were also examined in chronically Aβ_1–40 infused AD model rats using the eight-arm radial maze. In the AD model rats, nobiletin showed protective effects on Aβ_1–40-induced impairment of learning ability. These results suggest that nobiletin has the potential for becoming a novel lead compound for drug development for AD.     

Gomisin A decreases the LPS-induced expression of iNOS and COX-2 and activation of RIP2/NF-κB in mouse peritoneal macrophages

Gomisin A (GA), a lignan component contained in the fruit of Schisandra chinensis Baillon, improves hepatic cell degeneration, vasodilatory activity and insulin sensitivity. These effects also impact the immune system, including various inflammatory mediators and cytokines. In this study, the anti-inflammatory effect of GA on lipopolysaccharide-stimulated mouse peritoneal macrophages was studied. Pretreatment with GA attenuated the expression of receptor-interacting protein 2 (RIP2) and IκB kinase-β (IKK-β) as well as IKK-β phosphorylation. The activation of nuclear factor-kappa B (NF-κB) in the nucleus, the phosphorylation of IκBα and degradation of IκBα in the cytosol were suppressed by GA. GA decreased the production and mRNA expression of the inflammatory cytokines tumor necrosis factor-alpha (TNF-α) and interleukin (IL)-6. In addition, expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) and production of nitric oxide were decreased by pretreatment with GA. In conclusion, these results show that the anti-inflammatory properties of GA potentially result from the inhibition of COX-2, iNOS, IL-6, TNF-α and NO through the down-regulation of RIP2 and NF-κB activation. These results impact the development of potential health products for preventing and treating inflammatory diseases.     

孕酮抑制大鼠脑损伤后炎症反应诱导的神经细胞凋亡

目的:研究孕酮(progesterone,PROG)对大鼠脑损伤后皮质COX-2、iNOS、NF-κB和caspase-3表达的影响,以探讨PROG脑保护作用的可能机制。方法:雄性SD大鼠45只,随机分为假手术组、脑损伤组和PROG治疗组,按照改良的Feeney自由落体损伤装置制作大鼠脑损伤模型。PROG治疗组伤后1,6h腹腔注射PROG16mg/kg,各组于伤后24h取材。用免疫组织化学法及免疫蛋白印迹法,观察大鼠皮质COX-2、iNOS、NF-κB和caspase-3的免疫阳性细胞数和蛋白表达水平变化。结果:与假手术组大鼠相比,脑损伤组大鼠皮质COX-2、iN-OS、NF-κB和caspase-3阳性细胞数和蛋白表达水平较假手术组COX-2、iNOS、NF-κB和caspase-3显著增加(P0.05);PROG治疗组与脑损伤组比较,大鼠皮质COX-2、iNOS、NF-κB和caspase-3阳性细胞数和蛋白表达水平明显减少(P0.05)。结论:PROG可通过抑制NF-κB的活化,阻断NF-κB和iNOS自身强化的炎症反应过程,降低COX-2、caspase-3的表达,抑制脑损伤后的炎症反应和细胞凋亡,从而发挥脑保护作用。     

Stevioside Protects LPS-Induced Acute Lung Injury in Mice

Stevioside, a diterpene glycoside component of Stevia rebaudiana, has been known to exhibit anti-inflammatory properties. To evaluate the effect and the possible mechanism of stevioside in lipopolysaccharide (LPS)-induced acute lung injury, male BALB/c mice were pretreated with stevioside or dexamethasone 1 h before intranasal instillation of LPS. Seven hours later, tumor necrosis factor-α, interleukin-1β, and interleukin-6 in bronchoalveolar lavage fluid (BALF) were measured by using enzyme-linked immunosorbent assay. The number of total cells, neutrophils, and macrophages in the BALF were also determined. The right lung was excised for histological examination and analysis of myeloperoxidase activity and nitrate/nitrite content. Cyclooxygenase 2 (COX-2), inducible NO synthase (iNOS), nuclear factor-kappa B (NF-κB), inhibitory kappa B protein were detected by western blot. The results showed that stevioside markedly attenuated the LPS-induced histological alterations in the lung. Stevioside inhibited the production of pro-inflammatory cytokines and the expression of COX-2 and iNOS induced by LPS. In addition, not only was the wet-to-dry weight ratio of lung tissue significantly decreased, the number of total cells, neutrophils, and macrophages in the BALF were also significantly reduced after treatment with stevioside. Moreover, western blotting showed that stevioside inhibited the phosphorylation of IκB-α and NF-κB caused by LPS. Taken together, our results suggest that anti-inflammatory effect of stevioside against the LPS-induced acute lung injury may be due to its ability of inhibition of the NF-κB signaling pathway. Stevioside may be a promising potential therapeutic reagent for acute lung injury treatment.     

Epigallocatechin gallate stimulates the neuroreactive salivary secretomotor system in autoimmune sialadenitis of MRL-Faslpr mice via activation of cAMP-dependent protein kinase A and inactivation of nuclear factor κB

Abstract

The water channel aquaporin 5 (AQP5) plays a crucial role in regulating salivary flow rates. Xerostomia is often observed in patients with Sjögren's syndrome, and this is attributed to reduced AQP5 expression in the salivary glands. Recently, anti-type 3 muscarinic cholinergic receptors (M₃R) autoantibodies and nuclear factor κB (NF-κB) have been found to be negative regulators of AQP5 expression in the salivary gland. Anti-M₃R autoantibodies desensitize M₃R to salivary secretagogues in Sjögren's syndrome, while activated NF-κB translocates to nuclei and binds to the AQP5 gene promoter, resulting in the suppression of AQP5 expression. We previously documented that epigallocatechin gallate (EGCG), which is a robust antioxidant contained in green tea, ameliorates oxidative stress-induced tissue damage to the salivary glands of MRL/MpJ-lpr/lpr (MRL-Fas^lpr) mice, which are widely used as a model of Sjögren's syndrome. Reactive oxygen species (ROS) can activate NF-κB and inactivate protein kinase A (PKA), which is a key driver of AQP5 expression. In this study, we examined the effects of administering EGCG to MRL-Fas^lpr mice with autoimmune sialadenitis on the levels of AQP5, activated NF-κB p65 subunit, activated PKA, activated c-Jun N-terminal kinase (JNK) (an activator of NF-κB), inhibitor κB (IκB) and histone deacetylase 1 (HDAC1) (an inhibitor of NF-κB). In EGCG-treated mice, intense aster-like immunostaining for AQP5 was observed on the apical plasma membranes (APMs) of submandibular gland acinar cells. Likewise, PKA, IκB and HDAC1 were highly expressed in salivary gland tissues, whereas the expression of JNK and NF-κB p65 was negligible. Rank correlation and partial correlation analyses revealed that treatment with EGCG upregulated AQP5 expression on the APM of acinar cells through activation of PKA and inactivation of NF-κB, while IκB and HDAC1 played a pivotal role in the induction of AQP5 expression by PKA. Our study indicates that EGCG may have therapeutic potential for Sjögren's syndrome patients.     

Molecular Basis of the Anti-Inflammatory Property Exhibited by Cyclo-Pentano Phenanthrenol Isolated from Lippia nodiflora

The objective of this study was to assess the anti-inflammatory potential of the active molecule isolated from Lippia nodiflora and to understand its molecular dynamics in Vitro inflammation models. Human Peripheral Blood Mononuclear Cells were used as models to study mitogen induced lymphocyte proliferation, cytokine mRNA expression (TNF-α, IL-1β and IL-6) and intracellular protein levels of pro-inflammatory mediators (MAPK and NF-κB). The NO release levels, on treatment with the extract and molecule, were correlated with the underlying iNOS mRNA expression in the murine macrophage cell line RAW 264.7. RT-PCR for COX-2, MMP2 and MMP9 were also performed in the cell line. The rat basophilic leukemia cell line RBL-2H3 was used as an in Vitro model for PLA2 activity. Then, 20 μg/ml of Lippia nodiflora crude methanol extract and 10 μg/ml of the purified CPP were used for subsequent studies based on the IC50 values obtained in the proliferation assay. Results demonstrate that the isolated Cyclo-pentano phenanthrenol inhibits TNF-α, IL-1β and IL-6 expression, NO release via iNOS suppression, prostaglandin biosynthesis via PLA2 and COX-2 inhibition and the activation of intracellular targets, MAPK and NF-κB. We conclude, cyclo-pentano phenanthrenol exerts its anti-inflammatory effect via inhibition of MAPK phosphorylation and NF-κB translocation.     

Hesperetin Suppresses Inflammatory Responses in Lipopolysaccharide-Induced RAW 264.7 Cells via the Inhibition of NF-κB and Activation of Nrf2/HO-1 Pathways

Hesperetin (Hesp), a common flavanone glycoside, was extracted from the fruit peel of Citrus aurantium L. (Rutaceae). Hesp has been shown to possess various biological properties, including antioxidant, neuroprotective, and anti-inflammatory properties. In this study, we investigated the protective effect of Hesp on inflammatory responses in lipopolysaccharide (LPS)-induced RAW 264.7 cells. Our results indicated that Hesp treatment dramatically suppressed secretion of tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-1β; reduced inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) gene expression; inhibited NF-κB (p65) phosphorylation; and blocked IκBα phosphorylation and degradation. Further studies revealed Hesp markedly enhanced the heme oxygenase (HO)-1 and nuclear factor erythroid 2-related factor 2 (Nrf2) expression, which were involved with inducing Nrf2 nuclear translocation and decreasing Keap1 protein expression. Together, these results indicated that the anti-inflammatory effect of Hesp may be associated with NF-κB inhibition and Nrf2/HO-1 activation.     

糖尿病大鼠心肌NF-κB、iNOS、COX-2表达的研究

目的：观察核因子-κＢ（ＮＦ-κＢ）、诱导型一氧化氮合酶（iNOS）以及环氧化酶-2（COX-2）3种炎症因子在糖尿病大鼠心肌组织的表达。方法:30只SD大鼠随机分为正常对照组和糖尿病组，糖尿病组大鼠按60 mg/kg的剂量1次性腹腔注射链脲菌素。实验于24周末结束，观察2组大鼠的体重、平均血糖浓度、心重指数。并取心肌组织石蜡切片分别行NF-κＢ、iNOS和COX-2免疫组化染色。同时用凝胶电泳迁移率（EMSA）的方法测定心肌组织ＮＦ-κＢ活性。结果:(1)糖尿病大鼠心肌组织ＮＦ-κＢ阳性表达细胞明显多于对照组；（2）EMSA方法显示，糖尿病大鼠心肌组织ＮＦ-κＢ表达强度明显高于对照组；（3）对照组大鼠心肌组织未见iNOS的表达，糖尿病大鼠见明显iNOS的表达；（4）对照组大鼠心肌组织偶见COX-2的表达，糖尿病大鼠见明显COX-2的表达。结论:NF-κＢ、iNOS和COX-2在糖尿病大鼠心肌组织中表达活性明显增强。     

Oleamide suppresses lipopolysaccharide-induced expression of iNOS and COX-2 through inhibition of NF-κB activation in BV2 murine microglial cells

Oleamide (cis-9-octadecenamide) is an endogenous sleep-inducing fatty acid amide that accumulates in the cerebrospinal fluid of the sleep-deprived animals. Microglia are the major immune cells involved in neuroinflammation causing brain damage during infection, ischemia, and neurodegenerative disease. In this study, we examined the effects of oleamide on LPS-induced production of proinflammatory mediators and the mechanisms involved in BV2 microglia. Oleamide inhibited LPS-induced production of NO and prostaglandin E2 as well as expression of iNOS and COX-2. We showed that oleamide blocked LPS-induced NF-κB activation and phosphorylation of inhibitor κB kinase (IKK). We also showed that oleamide inhibited LPS-induced phosphorylation of Akt, p38 MAPK, and ERK, activation of PI 3-kinase, and accumulation of reactive oxygen species (ROS). Finally, we showed that a specific antagonist of the CB2 receptor, AM630, blocked the inhibitory effects of oleamide on LPS-induced production of proinflammatory mediators and activation of NF-κB. Taken together, our results suggest that oleamide shows an anti-inflammatory effect through inhibition of NF-κB activation in LPS-stimulated BV2 microglia.     

Inhibition of NLRP3 Inflammasome Prevents LPS-Induced Inflammatory Hyperalgesia in Mice: Contribution of NF-κB,Caspase-1/11, ASC,NOX, and NOS Isoforms

The nucleotide-binding domain and leucine-rich repeat protein 3 (NLRP3), an intracellular signaling molecule that senses many environmental- and pathogen/host-derived factors, has been implicated in the pathogenesis of several diseases associated with inflammation. It has been suggested that NLRP3 inflammasome inhibitors may have a therapeutic potential in the treatment of NLRP3-related inflammatory diseases. The aim of this study was to determine whether inhibition of NLRP3 inflammasome prevents inflammatory hyperalgesia induced by lipopolysaccharide (LPS) in mice as well as changes in expression/activity of nuclear factor κB (NF-κB), caspase-1/11, nicotinamide adenine dinucleotide phosphate oxidase (NOX), and endothelial/neuronal/inducible nitric oxide synthase (eNOS/nNOS/iNOS) that may regulate NLRP3/apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC)/pro-caspase-1 inflammasome formation and activity by using a selective NLRP3 inflammasome inhibitor, MCC950. Male mice received saline (10 ml/kg; i.p.), LPS (10 mg/kg; i.p.), and/or MCC950 (3 mg/kg; i.p.). Reaction time to thermal stimuli within 1 min was evaluated after 6 h. The mice were killed and the brains, hearts, and lungs were collected for measurement of NF-κB, caspase-1, caspase-11, NLRP3, ASC, NOX subunits (gp91^phox; NOX2), and p47^phox; NOXO2), nitrotyrosine, eNOS, nNOS, iNOS, and β-actin protein expression, NOS activity, and interleukin (IL)-1β levels. LPS-induced hyperalgesia was associated with a decrease in eNOS, nNOS, and iNOS protein expression and activity as well as an increase in expression of NF-κB p65, caspase-1 p20, caspase-11 p20, NLRP3, ASC, gp91^phox, p47^phox, and nitrotyrosine proteins in addition to elevated IL-1β levels. The LPS-induced changes were prevented by MCC950. The results suggest that inhibition of NLRP3/ASC/pro-caspase-1 inflammasome formation and activity prevents inflammatory hyperalgesia induced by LPS in mice as well as changes in NF-κB, caspase-11, NOX2, NOXO2, and eNOS/nNOS/iNOS expression/activity.     

7,8-Dihydroxyflavone exhibits anti-inflammatory properties by downregulating the NF-κB and MAPK signaling pathways in lipopolysaccharide-treated RAW264.7 cells

7,8-Dihydroxyflavone (7,8-DHF), a member of the flavonoid family, has received considerable attention as a selective tyrosine kinase receptor B agonist. Several studies have indicated that 7,8-DHF has neurotrophic and antioxidant activities. However, little is known about the cellular and molecular mechanisms underlying the anti-inflammatory activity of 7,8-DHF. Therefore, we investigated whether 7,8-DHF affects the expression of inflammatory mediators in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Our results indicated that 7,8-DHF significantly attenuated secretion of LPS-induced inflammatory mediators nitric oxide (NO), prostaglandin E? (PGE?) and interleukin-1β (IL-1β) in RAW264.7 cells. Additionally, LPS-induced expression of inducible NO synthase (iNOS), cyclooxygenase (COX)-2 and IL-1β was decreased by pre-treatment with 7,8-DHF. Our results also showed that 7,8-DHF reduces LPS-induced nuclear factor-κB (NF-κB) activity via the suppression of the nuclear translocation of NF-κB p65 and the degradation of inhibitor κB (lκB). In addition, 7,8-DHF inhibited the phosphorylation of mitogen-activated protein kinases (MAPKs) such as extracellular-signal-related kinase (ERK), p38, and c-Jun N-terminal kinase (JNK). These results suggest that the anti-inflammatory property of 7,8-DHF is related to the downregulation of iNOS, COX-2 and IL-1β, due to NF-κB inhibition as well as to the negative regulation of MAPK activation in RAW264.7 cells. Thus, 7,8-DHF may be a novel therapeutic agent for the prevention of various inflammatory diseases.     

大花旋覆花内酯通过抑制NF-κB活化抗血管炎症反应

目的：以离体培养的血管环为研究对象，探讨大花旋覆花内酯（1-O-acetylbritannilactone, ABL）抑制脂多糖（ LPS ）诱导的血管炎症反应效应和分子机制。方法：将体外培养的血管环预先用 ABL孵育后，再用 LPS 刺激，提取组织总蛋白进行 Western blotting 分析。结果：ABL抑制LPS 诱导的 IKK 磷酸化活化和由此引发的 IκBα 的磷酸化降解，降低NF-κB水平，进而抑制NF-κB依赖的炎症因子iNOS、COX-2、ICAM-1和VCAM-1的表达。结论：ABL是一种调节 NF-κB 活性的制剂，具有抑制致炎因子表达，上调抑炎因子水平，维持两者平衡的作用，可消除 LPS 诱导的血管炎症反应。