Mechanism of anti-inflammatory activity of umbelliferone 6-carboxylic acid isolated from Angelica decursiva

Aims of the study

We recently reported the potential antioxidant and anti-inflammatory activities of umbelliferone 6-carboxylic acid (UMC) isolated from the whole plants of Angelica decursiva. In this study, we elucidated the anti-inflammatory mechanisms of UMC in vitro and in vivo.

Methods

The inhibitory effects of UMC on the production of nitric oxide (NO), prostaglandin E₂ (PGE₂), and tumor necrosis factor-α (TNF-α), the expression of nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), the activation of nuclear factor kappa B (NF-κB) were evaluated using lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. The reactive oxygen species (ROS) generation inhibitory activity of UMC was evaluated using t-butyl hydroperoxide (t-BHP)-induced RAW 264.7 cells. Furthermore, the in vivo anti-inflammatory activity of UMC was evaluated using carrageenan induced mouse paw edema model.

Results

UMC dose-dependently inhibited NO and PGE₂ production by down-regulating iNOS and COX-2 protein expression in LPS-stimulated RAW 264.7 macrophages. UMC also suppressed the production of the proinflammatory cytokine TNF-α in LPS stimulated RAW 264.7 cells in a concentration dependent manner. In addition, UMC dose-dependently prevented LPS-induced nuclear translocation of NF-κB in RAW 264.7 macrophages. Furthermore, UMC exhibited the inhibitory activity against t-BHP-induced ROS generation in RAW 264.7 cells with an IC₅₀ value of 705.1 μg/ml. Moreover, UMC inhibited λ-carrageenan induced mouse paw edema by 70.40 and 60.20% at doses of 50 and 25 mg/kg body weight, respectively.

Conclusion

The combined results of this study indicate that UMC is an important anti-inflammatory constituent of A. decursiva and its anti-inflammatory effect was due to its ability to inhibit the production of inflammatory mediators via inhibition of NF-κB activation pathway.     

Screening for anti-inflammatory and bronchorelaxant activities of 12 commonly used Chinese herbal medicines

The use of health supplements derived from medicinal herbs as self‐medication for the relief of respiratory tract pathology symptoms is increasing in Chinese communities as air pollution is worsening. Twelve herbs from two formulae of our previous studies were evaluated for their anti‐inflammatory, immunomodulatory and bronchorelaxant activities in this study. Among the extracts tested, those of Herba Schizonepetae and Radix Glycyrrhizae showed significant inhibitory effects on LPS‐induced nitric oxide production (p < 0.05) in mouse macrophage RAW264.7 cells, suggesting their anti‐inflammatory activities. Radix Scutellariae and Radix Glycyrrhizae extracts showed significant inhibitory effects on phytohaemagglutinin‐induced proliferation in human peripheral blood mononuclear cells (p < 0.05). These extracts also showed inhibition of TNF‐α, IFN‐γ and IL‐10 production. For the bronchorelaxant assay, Rhizoma Cynanchi Stauntonii and Radix Glycyrrhizae extracts showed potent attenuation of the acetylcholine‐ and carbachol‐induced contractions in rat trachea (p < 0.05), implying their relaxant activities. In conclusion, Herba Schizonepetae, Radix Glycyrrhizae, Radix Scutellariae and Rhizoma Cynanchi Stauntonii extracts were demonstrated to exert anti‐inflammatory, immunomodulatory and bronchorelaxant activities, which may help to ameliorate the symptoms of respiratory tract pathologies. The findings have thus provided some scientific evidence on the efficacy and mechanisms of action of these herbs, which are useful for the further development of clinical applications. Copyright © 2011 John Wiley & Sons, Ltd.     

TLR7在结核分枝杆菌感染中的作用研究

目的 将TLR7激活基序ssRNA加入结核分枝杆菌感染的小鼠巨噬细胞,研究TLR7被激活后在结核分枝杆菌感染中的作用。方法 结核分枝杆菌感染RAW264.7细胞,感染后加入化学合成的TLR7激活基序ssRNA,RT-PCR法检测感染不同时间之后细胞对细菌的吞噬率;无菌TritonX-100裂解细胞,罗氏培养基培养计数活细菌;电镜观察细胞内自噬小体;ELISA检测细胞上清中IL-12、TNF-α与IL-4的含量。结果 感染3 h后RAW264.7细胞吞噬率最高(P>0.05);处理3 h后电镜观察,ssRNA组细胞状态明显好于对照组;36 h后ssRNA组IL-12(P < 0.05)、IL-4(P < 0.05)水平高于对照组,细胞内活菌数量ssRNA组低于对照组(P < 0.05),48 h后IL-4(P <0.05)水平下降,TNF-α的含量上升(P < 0.05)。结论 TLR7能通过诱导细胞自噬、调节细胞因子产生等机制增强细胞杀结核分枝杆菌的能力,TLR7激活基序ssRNA可以用于治疗结核分枝杆菌感染。     

牛蒡低聚果糖对脂多糖诱导下RAW264.7细胞炎症模型的抗炎作用

目的 观察牛蒡低聚果糖（BFOS）对RAW264.7炎症细胞模型的抗炎作用。方法 用脂多糖（LPS）处理巨噬细胞系RAW264.7细胞,建立炎症模型,并用不同浓度BFOS处理。采用定量PCR检测环氧合酶2（COX-2）、一氧化氮合成酶（iNOS）、单核细胞趋化蛋白1（MCP-1）、白细胞介素6（IL-1）等炎性因子的表达水平,ELISA检测BFOS处理前后MCP-1、IL-6的分泌量。Western blot法检测COX-2、iNOS、κB抑制因子（IκB）、核转录因子κB p65（NF-κBp65）、细胞外信号调节激酶（Erk）、P38、c-Jun氨基末端激酶（JNK）的磷酸化蛋白表达水平。结果 与对照组相比,经BFOS处理后,细胞iNOS、COX-2、MCP-1及IL-6的水平表达显著下降(P<0.01)。BFOS处理组p-IκB、p-NF-κBp65、p-Erk、p-P38、p-JNK等蛋白表达较LPS单独处理组显著下降(P<0.01)。结论 BFOS对LPS 诱导的RAW264.7细胞炎症模型具有抗炎作用。     

楤木单体的结构改造及抗炎活性研究

目的对楤木Aralia elata中的单体成分金盏花苷E进行结构改造,并对其结构改造后的类似物进行体外抗炎活性研究。方法以天然易得的齐墩果酸为起始原料,经苷元28位羧基保护、3位糖苷化、28位羧基脱保护、28位羧基酰胺化、胺基侧链酰胺化、糖基苯甲酰基脱保护、甲叉基脱保护共7步反应制得目标化合物,利用巨噬细胞RAW264.7模型评价化合物的抗炎活性。结果设计并合成了10个金盏花苷E的结构类似物G1~G5和H1~H5,均经谱学技术确证结构。生物活性实验结果表明,10个化合物对RAW264.7细胞呈现不同程度的抗炎活性,其中化合物G1~G4、H1~H3的抗炎活性优于先导物。结论化合物G1~G5和H1~H5均为未见文献报道的新化合物,具有潜在的抗炎活性,值得深入研究。     

AcSDKP体外抑制脂多糖诱导的小鼠RAW264.7巨噬细胞促炎功能研究*

目的 探讨N-乙酰-丝氨酰-天门冬酰-赖氨酰-脯氨酸（AcSDKP）对小鼠RAW264.7巨噬细胞促炎功能的影响。方法 取小鼠RAW264.7巨噬细胞体外培养,分为对照组、脂多糖（LPS）组和LPS加不同浓度的AcSDKP（1 nmol/L、10 nmol/L和100 nmol/L）处理组。采用荧光定量PCR法检测细胞肿瘤坏死因子（TNF）-α、白细胞素（IL）-1β、IL-6和诱导型一氧化氮合成酶（iNOS）mRNA相对水平;使用Transwell小室检测RAW264.7细胞的趋化能力;采用Western blot法检测细胞iNOS、磷酸化的蛋白激酶复合体抑制物(p-IKK)、磷酸化的κB抑制蛋白(p-IκB)和磷酸化的P65（p-P65）蛋白表达水平。结果 LPS处理组TNF-α、IL-1β和IL-6 mRNA水平显著高于对照组【分别高出（41±2.1）倍、（1073±80.8）倍和（1726±110.2）倍,P<0.01】;AcSDKP（10 nmol/L和100 nmol/L）处理组TNF-α水平显著低于LPS处理组【分别降低19.0% 和39.3%,P<0.01】;AcSDKP（1 nmol/L、10 nmol/L和100 nmol/L）处理组IL-1β水平显著低于LPS处理组【分别降低22.08%、35.8%和38.2%,P<0.01】;AcSDKP（1 nmol/L、10 nmol/L和100 nmol/L）处理组IL-6水平显著低于LPS处理组【分别降低15.8%、35.7%和43.3%,P<0.01】;LPS处理组穿过小室的细胞数为（136±5.3）个/HP,显著高于对照组【（64±5.3）个/HP,P<0.01】,而AcSDKP处理组穿过小室的细胞数【分别为（105±4.8）、（85.3±5.0）和（73.7±5.6）个/HP】,显著低于LPS组【（136±5.3）个/HP,P<0.05】;LPS处理组iNOS mRNA和蛋白表达水平显著高于对照组【分别为（21±2.5）倍和（5.9±0.4）倍,P<0.01】,而AcSDKP处理组iNOS mRNA显著低于LPS处理组【分别降低37.8%、23.3%和33.1%,P<0.05】;在10 nmol/L和100 nmol/L浓度AcSDKP处理组,两种蛋白水平显著低于LPS处理组【分别降低27.0%和40.2%,P<0.05】;LPS处理组p-IKK、p-IκB和p-P65表达量均显著高于对照组【分别为（25.9±4.8）倍、（9.5±0.6）倍和（2.1±0.2）倍,P<0.01】,而AcSDKP（10 nmol/L）处理组三者水平较LPS处理组显著下降【分别为42.5%、17.8%和29.7%,P<0.05】。结论 AcSDKP可抑制LPS诱导的小鼠RAW264.7巨噬细胞的炎症反应,这一效应可能与阻断IKK/ IκB/NF-κB通路有关。     

灯盏乙素对LPS诱导的RAW264.7细胞炎症介质分泌的影响

[目的]研究灯盏乙素对脂多糖(LPS)诱导的RAW264.7细胞炎症的影响,初步探讨其抗炎作用机制。[方法]用噻唑蓝(MTT)法检测灯盏乙素对RAW264.7细胞活力的影响;用Griess法检测灯盏乙素对LPS诱导的RAW264.7细胞中一氧化氮(NO)生成的影响;用荧光素酶报告质粒法检测灯盏乙素对LPS诱导的核转录因子(NF-κB)转录活性的影响;用实时定量聚合酶链反应(PCR)法检测灯盏乙素对LPS诱导的RAW264.7细胞中NF-κB靶基因肿瘤坏死因子-α(TNF-α)、白介素-1β(IL-1β)、白介素-6(IL-6)m RNA表达的影响。[结果]0.01~10μmol/L的灯盏乙素处理24 h后对RAW264.7活力无显著影响;1、10μmol/L的灯盏乙素可以显著抑制LPS诱导的NO的生成及NF-κB转录活性;灯盏乙素可以不同程度的抑制LPS诱导的RAW264.7细胞NF-κB靶基因TNF-α、IL-1β、IL-6m RNA的上调作用。[结论]灯盏乙素可能通过抑制NF-κB的活化及炎症因子的表达发挥一定的抗炎作用。     

半边旗有效成分5F体内外的抗炎作用

目的:通过建立体内外炎症模型,观察半边旗有效成分5F的抗炎作用。方法:建立脂多糖(LPS)诱导的RAW264.7细胞炎症模型,并用不同浓度5F处理,CCK-8法检测5F的细胞毒性,采用Griess法检测上清液中一氧化氮(NO)含量,ELISA法检测肿瘤坏死因子-α(TNF-α)、白细胞介素-1β(IL-1β)、白细胞介素-6(IL-6)和前列腺素E2(PGE2)含量,Western blot法检测诱导型一氧化氮合酶(i NOS)和环氧酶-2(COX-2)表达水平。雄性ICR小鼠60只,建立巴豆油和花生四烯酸诱导的耳肿胀模型,造模后随机分为模型组、阳性组和5F组,每组10只,5F组给予100 mg·kg-15F溶液,阳性组给予地塞米松0.8 mg·kg-1或吲哚美辛1 mg·kg-1,模型组给予同体积生理盐水。各组均连续给药7 d。观察5F对小鼠耳肿胀的抑制作用。结果:5F在0~40 mg·L-1的剂量内对RAW264.7细胞无明显毒性作用,10,20,40 mg·L-1的5F可依赖性抑制LPS诱导的NO释放(P<0.01),20,40 mg·L-1的5F可以降低PGE2含量(P<0.01),40 mg·L-1的5F显著性抑制i NOS和COX-2蛋白表达(P<0.05),10,20,40 mg·L-1的5F显著降低TNF-α和IL-1β含量(P<0.01),20,40 mg·L-1的5F显著降低IL-6含量(P<0.01),100 mg·kg-1的5F对巴豆油和花生四烯酸诱导的耳肿胀都有显著抑制作用(P<0.05)。结论:5F可以抑制LPS诱导的RAW264.7细胞炎症反应,抑制巴豆油和花生四烯酸诱导的耳肿胀,其抗炎作用与抑制i NOS和COX-2表达,减少炎症因子TNF-α,IL-1β,IL-6,NO和PGE2含量有关。     

地乌三萜皂苷W1对破骨细胞分化和骨吸收功能的影响

目的探讨地乌三萜皂苷类成分W1对体外破骨细胞分化及骨吸收功能的影响。方法3个不同浓度（0．0625,0．125,0．25μg／ml）的W1与核因子-κB受体活化因子配体（receptor activator of nuclear factor kB ligand,RANKL）诱导的小鼠单核／巨噬细胞RAW264．7共孵育7天,抗酒石酸酸性磷酸酶（tartrate resistant acid phosphatase,TRAP）染色观察TRAP阳性多核细胞的形成,甲苯胺蓝染色及扫描电镜观察骨吸收陷窝的形成,图像分析计算骨吸收陷窝面积百分比;同3个浓度的W1与RANKL诱导的RAW264．7细胞共孵育24小时后收集细胞上清液,放射免疫法检测肿瘤坏死因子α（tumor necrosis factor-α,TNF-α）的含量;甲基噻唑基四唑（methyl thiazolyl tetrazolium,MTT）法检测W1对RAW264．7细胞毒性影响。结果RANKL组诱导RAW264．7细胞形成多量TRAP阳性多核细胞,形成明显的骨吸收陷窝,并诱导TNF-α在RAW264．7细胞上清中异常高表达;与RANKL组相比,3个浓度的W1均能显著减少TRAP阳性细胞数（P〈0．01）,显著减少骨吸收陷窝面积（P〈0．01,P〈0．001,P〈0．001）,明显降低TNF-α的表达量（P〈0．05,P〈0．01,P〈0．01）,且未观察到对RAW264．7的细胞毒性。结论W1对由RANKL诱导的体外破骨细胞分化和骨吸收功能有一定的负调节作用。