Praeruptorin a inhibits lipopolysaccharide‐induced inflammatory response in murine macrophages through inhibition of NF‐κB pathway activation

Praeruptorin A (PA) is a pyranocoumarin compound isolated from the dried root of Peucedanum praeruptorum Dunn (Umbelliferae). However, the antiinflammatory effect of PA has not been reported. The present study investigated the antiinflammatory effect of PA in lipopolysaccharide (LPS)‐stimulated RAW 264.7 macrophage cells. PA significantly inhibited the LPS‐induced production of nitric oxide (NO), interleukin‐1β (IL‐1β) and tumor necrosis factor‐α (TNF‐α). The mRNA and protein expressions of inducible nitric oxide synthase (iNOS), IL‐1β and TNF‐α were also suppressed by this compound. Further study showed that PA decreased the cytoplasmic loss of inhibitor κB‐α (IκB‐α) protein and inhibited the translocation of NF‐κB from cytoplasm to nucleus. Taken together, the results suggest that PA may exert antiinflammatory effects in vitro in LPS‐stimulated RAW 264.7 macrophages through inhibition of NF‐κB signal pathway activation. Copyright © 2010 John Wiley & Sons, Ltd.     

Down‐regulatory effect of usnic acid on nuclear factor‐κB‐dependent tumor necrosis factor‐α and inducible nitric oxide synthase expression in lipopolysaccharide‐stimulated macrophages RAW 264.7

The purpose of this study was to investigate the molecular mechanisms that are responsible for the antiinflammatory effect of usnic acid (UA). UA is one of the most common and abundant lichen metabolites. The present study examined the effects of UA on the tumor necrosis factor‐α (TNF‐α) and nitric oxide (NO) production induced by lipopolysaccharide (LPS) in RAW264.7 macrophages and the underlying molecular mechanisms. UA decreased the TNF‐α level in LPS‐stimulated RAW264.7 macrophages in dose‐dependent manner, the IC₅₀ value was 12.8 µM. RT‐PCR analysis indicated that it inhibited TNF‐α mRNA expression. Furthermore, it inhibited NO production in LPS‐activated RAW264.7 macrophages, the IC₅₀ value was 4.7 µM. Western blot analysis showed that UA attenuated LPS‐induced synthesis of iNOS protein and nuclear translocation of NF‐κB p65 in the macrophages, in parallel. UA also inhibited LPS‐mediated I‐κBα degradation. Taken together, this suggests that UA has an antiinflammatory effect by inhibiting TNF‐α and iNOS expression, possibly through suppression of nuclear translocation of NF‐κB p65 and I‐κBα degradation. Copyright © 2008 John Wiley & Sons, Ltd.     

Myrislignan Attenuates Lipopolysaccharide‐induced Inflammation Reaction in Murine Macrophage Cells Through Inhibition of NF‐κB Signalling Pathway Activation

Myrislignan is a new kind of lignan isolated from Myristica fragrans Houtt. Its antiinflammatory effects have not yet been reported. In the present study, the antiinflammatory effects and the underlying mechanisms of myrislignan in lipopolysaccharide (LPS)‐induced inflammation in murine RAW 264.7 macrophage cells were investigated. Myrislignan significantly inhibited LPS‐induced production of nitric oxide (NO) in a dose‐dependent manner. It inhibited mRNA expression and release of interleukin‐6 (IL‐6) and tumour necrosis factor‐α (TNF‐α). This compound significantly inhibited mRNA and protein expressions of inducible NO synthase (iNOS) and cyclooxygenase‐2 (COX‐2) dose‐dependently in LPS‐stimulated macrophage cells. Further study showed that myrislignan decreased the cytoplasmic loss of inhibitor κB‐α (IκB‐α) protein and the translocation of NF‐κB from cytoplasm to the nucleus. Our results suggest that myrislignan may exert its antiinflammatory effects in LPS‐stimulated macrophages cells by inhibiting the NF‐κB signalling pathway activation. Copyright © 2012 John Wiley & Sons, Ltd.     

Anti-inflammatory effects of Scutellaria baicalensis water extract on LPS-activated RAW 264.7 macrophages

Aim of the study

The root of Scutellaria baicalensis Georgi (Labiatae), also known as Scutellariae Radix, possesses anticancer, antiviral, and anti-inflammatory properties. And it is one of the most widespread herbal remedies used in Oriental medicine. In the present study, we investigated the effects of Scutellariae Radix water extract (SR) on proinflammatory mediators secreted from lipopolysaccharide (LPS)-induced RAW 264.7 macrophages.

Material and methods

Cell viability was assessed by MTT assay and nitric oxide (NO) concentration in the cultured medium was determined by the Griess reaction. Various Cytokines released from LPS-induced Raw 264.7 cells were measured in the cell culture supernatants using a multiplex bead array assay based on xMAP technology.

Results

We found that SR significantly inhibited the production of NO, interleukin (IL)-3, IL-6, IL-10, IL-12p40, IL-17, interferon-inducible protein (IP)-10, keratinocyte-derived chemokine (KC), and vascular endothelial growth factor (VEGF) in LPS-induced RAW 264.7 cells at the concentrations of 25, 50, 100, 200 μg/ml (p < 0.05).

Conclusions

These results suggest that SR has anti-inflammatory activity related with its inhibition of NO, cytokine, chemokine, and growth factor production in macrophages.     

Antioxidant and antiinflammatory activity of pine pollen extract in vitro

To determine the medicinal properties of pine pollen, the antioxidant and antiinflammatory activities of the ethanol extract of pine pollen extract (PPE) were investigated. PPE displayed a strong free radical scavenger activity on 1,1‐diphenyl‐2‐picrylhydrazyl radical and hydrogen peroxide. It was observed also that the antioxidant activity, measured by the ferric thiocyanate method, increased with the addition of PPE to the linoleic acid emulsion system. PPE was also found to inhibit significantly the amount of malondialdehyde and protein carbonyls formed from liver homogenate. Like the antioxidant activity, the reducing power of PPE was excellent. Thereafter, the study investigated the effects of PPE in modulating the production of pro‐inflammatory mediators in lipopolysaccharide (LPS)‐activated RAW 264.7 macrophages, and the effect of PPE on interleukin (IL)‐1β‐induced matrix metalloproteinases (MMPs) production and mitogen‐activated protein kinases (MAPKs) activation in the human synovial sarcoma cell line, SW982. PPE was found to inhibit the production of nitric oxide, tumor necrosis factor‐α, IL‐1 and IL‐6 in LPS‐activated macrophages. Treatment with PPE at 10 µg/mL significantly (p < 0.05) inhibited IL‐1β‐induced MMPs (MMP‐1 and ‐3) production in SW982 cells. IL‐1β‐induced JNK activation was inhibited by PPE (10 µg/mL), whereas p38 and ERK1/2 were not affected. These findings suggest that pine pollen is a potential antioxidant and beneficial for inflammatory conditions through down‐regulation of JNK and MMPs. Copyright © 2008 John Wiley & Sons, Ltd.     

Tectorigenin protects against experimental fulminant hepatic failure by regulating the TLR4/mitogen‐activated protein kinase and TLR4/nuclear factor‐κB pathways and autophagy

Tectorigenin has received attention due to its antiproliferation, anti‐inflammatory, and antioxidant activities. In this study, we investigated the effects of tectorigenin on lipopolysaccharide (LPS)/D‐galactosamine(D‐GalN)‐induced fulminant hepatic failure (FHF) in mice and LPS‐stimulated macrophages (RAW 264.7 cells). Pretreatment with tectorigenin significantly reduced the serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), histological injury, apoptosis, and the mortality of FHF mice, by suppressing the production of inflammatory cytokines such as TNF‐α and IL‐6. Tectorigenin also suppressed the activation of the inflammatory response in LPS‐stimulated RAW 264.7 cells. Tectorigenin‐induced protection is mediated through its mitigation of TLR4 expression, inhibition of mitogen‐activated protein kinase (MAPK) and nuclear factor‐κB (NF‐κB) pathway activation, and promotion of autophagy in FHF mice and LPS‐stimulated RAW 264.7 cells. Therefore, tectorigenin has therapeutic potential for FHF in mice via the regulation of TLR4/MAPK and TLR4/NF‐κB pathways and autophagy.     

青蒿琥酯对内毒素诱导的一氧化氮合成的抑制作用

目的 :探讨青蒿琥酯对内毒素诱导的巨噬细胞一氧化氮 (NO)合成的影响。方法 :①用内毒素 (LPS)或LPS合并γ 干扰素作为巨噬细胞 (RAW 264.7)的NO合成诱导剂 ,加入不同浓度的青蒿琥酯 ,培养后取上清液 ,用Griess试剂测定NO产生量。②Balb/c小鼠肌肉注射青蒿琥酯 5 0mg·kg^-1·d^-1×3d ,收集腹腔巨噬细胞 ,测定LPS对细胞的NO诱生能力。结果 :LPS 1.0 ,0.2μg·ml^-1或γ-干扰素 100u合并LPS 1.0 ,0.2 ,0.04μg·ml^-1作用于RAW 264.7细胞 ,均可诱导大量NO合成。青蒿琥酯对LPS或LPS合并干扰素诱导的NO合成均有明显的抑制作用 ,其抑制作用具有明显的量效关系。经青蒿琥酯治疗后的小鼠 ,其腹腔巨噬细胞对LPS的反应性降低 ,其受LPS刺激后产生的NO量明显降低。结论 :青蒿琥酯可降低LPS诱导的炎性因子的产生 ,减轻炎症反应。     

Anti‐inflammatory Activities of Gouania leptostachya Methanol Extract and its Constituent Resveratrol

Gouania leptostachya DC. var. tonkinensis Pitard. Rhamnaceae is a traditional medicinal plant used in Thailand for treating various inflammatory symptoms. However, no systematic studies have been performed concerning the anti‐inflammatory effects or molecular mechanisms of this plant. The immunopharmacological activities of a methanol extract from the leaves and twigs of G. leptostachya (Gl‐ME) were elucidated based on the gastritis symptoms of mice treated with HCl/EtOH and the inflammatory responses, such as nitric oxide (NO) release and prostaglandin E₂ (PGE₂) production, from RAW264.7 cells and peritoneal macrophages. Moreover, inhibitory target molecules were also assessed. Gl‐ME dose‐dependently diminished the secretion of NO and PGE₂ from LPS‐stimulated RAW264.7 cells and peritoneal macrophages. The gastritis lesions of HCl/EtOH‐treated mice were also attenuated after Gl‐ME treatment. The extract (50 and 300 µg/mL) clearly reduced mRNA expression of inducible NO synthase (iNOS) and cyclooxygenase (COX)‐2, nuclear translocation of p65/nuclear factor (NF)‐κB, phosphorylation of p65‐activating upstream enzymes, such as protein kinase B (AKT), inhibitor of κBα kinase (IKK), and inhibitor of κB (IκBα), and the enzymatic activity of Src. By HPLC analysis, one of the major components in the extract was revealed as resveratrol with NO and Src inhibitory activities. Moreover, this compound suppressed NO production and HCl/EtOH‐induced gastric symptoms. Therefore, these results suggest that Gl‐ME might be useful as an herbal anti‐inflammatory medicine through the inhibition of Src and NF‐κB activation pathways. The efficacy data of G. leptostachya also implies that this plant could be further tested to see whether it can be developed as potential anti‐inflammatory preparation. Copyright © 2014 John Wiley & Sons, Ltd.     

羧甲基茯苓多糖对巨噬细胞极化的影响

目的:探讨羧甲基茯苓多糖(carboxymethylpachymaran,CMP)对巨噬细胞活化、吞噬、分泌、一氧化氮(nitric oxide,NO)和炎症因子的影响。方法:体内实验,将Balb/c小鼠分为生理盐水组和CMP组,生理盐水组腹腔注射生理盐水,CMP组腹腔注射CMP溶液100 mg·kg~(-1),5 d后收集小鼠腹腔巨噬细胞,采用流式细胞术检测细胞吞噬功能。体外实验,将巨噬细胞RAW264.7分为空白组、脂多糖(lipopolysaccharides,LPS)组和CMP低、中、高剂量组,并分别加入培养基,LPS(0.1 mg·L-1)和CMP(400,800,1 600 mg·L-1)共孵育48 h。流式细胞术检测巨噬细胞的活化标志分子CD86表达水平和吞噬功能,荧光显微镜观察巨噬细胞吞噬荧光微球情况。收集细胞上清液,Griess法检测NO分泌水平,流式细胞微珠阵列法(cytometric bead array,CBA)检测白细胞介素-6(interleukin-6,IL-6),白细胞介素-10(interleukin-10,IL-10),单核细胞趋化蛋白-1(monocyte chemoattractant protein-1,MCP-1)和肿瘤坏死因子(tumor necrosis factor,TNF)的分泌水平。结果:体内实验结果显示,与生理盐水组比较,CMP组巨噬细胞吞噬率和吞噬指数均显著升高(P0.05)。体外实验结果显示,与空白组比较,CMP各剂量组和LPS组巨噬细胞表达CD86分子水平显著升高(P0.05);荧光显微镜下观察到CMP各剂量组和LPS组巨噬细胞吞噬2个以上荧光微球的数量明显增加,流式检测结果也表明CMP各剂量组和LPS组巨噬细胞吞噬率和吞噬指数显著升高(P0.05);LPS诱导巨噬细胞分泌NO,IL-6,IL-10,MCP-1和TNF,然而CMP未见此效应,且NO,MCP-1和TNF分泌水平均低于空白组。结论:CMP可以刺激巨噬细胞活化,增强其吞噬功能,但不能促进巨噬细胞释放NO和炎症因子,因此推测其促进巨噬细胞向M2型极化。     

Modulation of cerulein‐induced pancreatic inflammation by hydroalcoholic extract of curry leaf (Murraya koenigii)

This study was performed to study the in vitro and in vivo efficacy of hydroalcoholic extract of curry leaf (CLE) rich in carbazole alkaloids, against LPS‐induced inflammation in Raw 264.7 macrophages and cerulein‐induced acute pancreatitis, respectively. CLE was characterized by Fourier‐transform infrared (FTIR) and liquid chromatography–mass spectrometry. Raw 264.7 cells were stimulated with LPS (2 μg/ml) and treated with CLE. The animals were treated with two doses of CLE (100 and 300 mg/kg). Plasma biochemistry, tissue lipid peroxidation, cytokines, and histological examination were evaluated. CLE was found to decently scavenge the activity of DPPH radical. It dose dependently suppressed nitrite production and oxidative stress in macrophages. CLE alleviated LPS‐induced inflammation in macrophages as evident from the results of various inflammatory cytokines (IL‐1β, IL‐6, and TNF‐α). In vivo, CLE reduced cerulein‐induced pancreatic edema. CLE significantly abrogated the cerulein‐induced lipid peroxidation, nitrite, MPO, and GSH levels. The inflammatory cytokines and p65‐NFκB activity were significantly reduced by CLE. Mechanistically, CLE reduced the expression of NT, MPO, IL‐1β, ICAM‐1, and COX‐2, and increased the expression of Nrf2. It reduced distant organ damage markers as well. We report for the first time that CLE holds substantial potential for the prevention of acute pancreatitis.     

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.     

Ethanol extract of Prunella vulgaris var. lilacina inhibits HMGB1 release by induction of heme oxygenase-1 in LPS-activated RAW 264.7 cells and CLP-induced septic mice

The ethanol extract of the flower of P. vulgaris var. lilacina (EEPV) has been used traditionally as an antiinflammatory agent in many countries. Inducers of heme oxygenase‐1 (HO‐1) reduce high mobility group box 1 (HMGB1), a late phase cytokine, in sepsis. Although EEPV has been used as an antiinflammatory agent, no report is available as to whether it modifies HMGB1 in sepsis due to HO‐1 induction. It was found that EEPV increased HO‐1 protein expression in RAW 264.7 cells, which was significantly inhibited by LY294002, but not PD98059, SB203580 or SP600125. In addition, EEPV activated NF‐E2‐related factor (Nrf2) to move from the cytosol to the nucleus, and EEPV‐induced HO‐1 and activation of ARE‐luciferase activity were significantly reduced by siNrf2 transfection and LY294002 but not SB203508. EEPV also significantly inhibited NF‐κB luciferase activity, and decreased both iNOS/NO and COX‐2/PGE₂ production in lipopolysaccharide (LPS)‐stimulated macrophages which was reversed by siHO‐1 RNA transfection. Importantly, EEPV inhibited HMGB1 release in LPS‐activated macrophages in a PI3K‐sensitive manner and reduced serum HMGB1 level and lung HMGB1 expression in cecal ligation and puncture (CLP)‐induced septic mice. It is concluded that EEPV induces HO‐1 expression through PI3K/Nrf2 signal pathways, which may be beneficial for the treatment of sepsis due to a reduction of HMGB1 release. Copyright © 2011 John Wiley & Sons, Ltd.