Anti-Inflammatory Effect of Mangostenone F in Lipopolysaccharide-Stimulated RAW264.7 Macrophages by Suppressing NF-κB and MAPK Activation

Mangostenone F (MF) is a natural xanthone isolated from Garcinia mangostana. However, little is known about the biological activities of MF. This study was designed to investigate the anti-inflammatory effect and underlying molecular mechanisms of MF in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. MF dose-dependently inhibited the production of NO, iNOS, and pro-inflammatory cytokines (TNF-α, IL-6, and IL-1β) in LPS-stimulated RAW264.7 macrophages. Moreover, MF decreased the NF-κB luciferase activity and NF-κB DNA binding capacity in LPS-stimulated RAW264.7 macrophages. Furthermore, MF suppressed the NF-κB activation by inhibiting the degradation of IκBα and nuclear translocation of p65 subunit of NF-κB. In addition, MF attenuated the AP-1 luciferase activity and phosphorylation of ERK, JNK, and p38 MAP kinases. Taken together, these results suggest that the anti-inflammatory effect of MF is associated with the suppression of NO production and iNOS expression through the down-regulation of NF-κB activation and MAPK signaling pathway in LPS-stimulated RAW264.7 macrophages.     

Anti-neuroinflammatory Activity of a Novel Cannabinoid Derivative by Inhibiting the NF-κB Signaling Pathway in Lipopolysaccharide-Induced BV-2 Microglial Cells

Microglial-mediated neuroinflammation has recently been implicated as one of the important mechanisms responsible for the progression of neurodegenerative diseases. Activated microglia cells produce various neurotoxic factors that are harmful to neurons. Therefore, suppression of the inflammatory response elicited by activated microglia is considered a potential therapeutic target for neurodegenerative diseases. The cannabinoid (CB) system is widespread in the central nervous system and is very crucial for modulating a spectrum of neurophysiological functions such as pain, appetite, and cognition. In the present study, we synthesized and investigated a novel CB derivative (CD-101) for its ability to suppress lipopolysaccharide (LPS)-mediated activation of BV-2 microglial cells and subsequent release of various inflammatory mediators. CD-101 significantly inhibited the production of inflammatory markers such as nitric oxide, cyclooxygenase-2, and pro-inflammatory cytokines such as tumor necrosis factor-α, interleukin-1β, and interleukin-6. The anti-neuroinflammatory effect of this novel cannabinoid derivative occurred by inhibiting p38MAPK phosphorylation and by decreasing nuclear translocation of p65 subunit of nuclear factor kappa-B in LPS-stimulated BV-2 microglial cells. These results suggest that the use of the cannabinoid derivative CD-101 might be a potential therapeutic target against neuroinflammatory disorders.     

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.     

Cloricromene in endotoxemia: role of NF-κB

In this study we investigated, for the first time in vivo, the effect of cloricromene, a cumarine derivative, on NF-B activation in endotoxin-treated rats. Endotoxemia was induced in male rats by the intravenous injection of Salmonella typhosa lipopolysaccharide (LPS; 2 mg/kg/i.v.). In vivo treatment with cloricromene (2 mg/kg/i.v.) 30 min before lipopolysaccharide administration reversed the LPS-induced loss in tone of the aortic rings, improved their reactivity to phenylephrine, decreased both nitric oxide (NO) and TNF- serum levels by inhibiting LPS-induced inducible NO synthase and TNF- mRNA expression, and interestingly inhibited LPS-induced NF-B activation. Our data suggest that cloricromene protects rats from LPS by blocking LPS-induced NF-B activation, leading to inhibition of NO and TNF- overproduction and thereby reversing the LPS-induced vascular hyporeactivity.     

NF-κB的研究进展

核因子κB(NF-κB)是一种广泛存在于真核细胞内的基因多向性转录因子,属于Rel家族,于1986年首次在小鼠B淋巴细胞的核抽提物中发现,因能与免疫球蛋白κ链基因的     

Sophoricoside isolated from Sophora japonica ameliorates contact dermatitis by inhibiting NF-κB signaling in B cells

Sophoricoside (SOPH) is an isoflavone isolated from Sophora japonica (Leguminosae). In this study, the inhibitory effect of SOPH on contact dermatitis was investigated. At dosages of 3 and 10 mg/kg, SOPH ameliorated 2,4-dinitrochlorobenzene-induced acute and chronic contact dermatitis by 50–70%. As cellular targets, SOPH mainly affected the functions of B cells rather than T cells, macrophages and dendritic cells. As signaling targets, SOPH inhibited the phosphorylation and degradation of IκBα/β and the nuclear translocation of NF-κB p65 in B cells, but not in dendritic cells and macrophages. SOPH did not affect the phosphorylation of ERK, p38, and JNK MAPKs, in B cells, dendritic cells, and macrophages. Taken together, these results suggest that SOPH ameliorates contact dermatitis by inhibiting mainly NF-κB signaling in B cells.     

Sugar-Modified Poly(propylene imine) Dendrimers Stimulate the NF-κB Pathway in a Myeloid Cell Line

Purpose

Fourth-generation poly(propylene imine) dendrimers fully surface-modified by maltose (dense shell, PPI-m DS) were shown to be biocompatible in cellular models, which is important for their application in drug delivery. We decided to verify also their inherent bioactivity, including immunomodulatory activity, for potential clinical applications. We tested their effects on the THP-1 monocytic cell line model of innate immunity effectors.

Methods

To estimate the cytotoxicity of dendrimers the reasazurin assay was performed. The expression level of NF-κB targets: IGFBP3, TNFAIP3 and TNF was determined by quantitative real-time RT-PCR. Measurement of NF-κB p65 translocation from cytoplasm to nucleus was conducted with a high-content screening platform and binding of NF-κB to a consensus DNA probe was determined by electrophoretic mobility shift assay. The cytokine assay was performed to measure protein concentration of TNFalpha and IL-4.

Results

We found that PPI-m DS did not impact THP-1 viability and growth even at high concentrations (up to 100 μM). They also did not induce expression of genes for important signaling pathways: Jak/STAT, Keap1/Nrf2 and ER stress. However, high concentrations of 4th generation PPI-m DS (25–100 μM), but not their 3rd generation counterparts, induced nuclear translocation of p65 NF-κB protein and its DNA-binding activity, leading to NF-κB-dependent increased expression of mRNA for NF-κB targets: IGFBP3, TNFAIP3 and TNF. However, no increase in pro-inflammatory cytokine secretion was detected.

Conclusion

We conclude that maltose-modified PPI dendrimers of specific size could exert a modest immunomodulatory effect, which may be advantageous in clinical applications (e.g. adjuvant effect in anti-cancer vaccines).

     

Icariin potentiates the antitumor activity of gemcitabine in gallbladder cancer by suppressing NF-κB

Aim:

Gemcitabine has been increasingly prescribed for the treatment of gallbladder cancer. However, the response rate is low. The aim of this study is to determine whether icariin, a flavonoid isolated from Epimedi herba, could potentiate the antitumor activity of gemcitabine in gallbladder cancer.

Methods:

Human gallbladder carcinoma cell lines GBC-SD and SGC-996 were tested. Cell proliferation and apoptosis were analyzed using MTT assay and flow cytometry, respectively. The expression of apoptosis- and proliferation-related molecules was detected with Western blotting. Caspase-3 activity was analyzed using colorimetric assay, and NF-κB activity was measured with ELISA. A gallbladder cancer xenograft model was established in female BALB/c (nu/nu) mice. The mice were intraperitoneally administered gemcitabine (125 mg/kg) in combination with icariin (40 mg/kg) for 2 weeks.

Results:

Icariin (40–160 μg/mL) dose-dependently suppressed cell proliferation and induced apoptosis in both GBC-SD and SGC-996 cells, with SGC-996 cells being less sensitive to the drug. Icariin (40 μg/mL) significantly enhanced the antitumor activity of gemcitabine (0.5 μmol/L) in both GBC-SD and SGC-996 cells. The mice bearing gallbladder cancer xenograft treated with gemcitabine in combination with icariin exhibited significantly smaller tumor size than the mice treated with either drug alone. In GBC-SD cells, icariin significantly inhibited both the constitutive and gemcitabine-induced NF-κB activity, enhanced caspase-3 activity, induced G₀-G₁ phase arrest, and suppressed the expression of Bcl-2, Bcl-xL and surviving proteins.

Conclusion:

Icariin, by suppressing NF-κB activity, exerts antitumor activity, and potentiates the antitumor activity of gemcitabine in gallbladder cancer. Combined administration of gemcitabine and icariin may offer a better therapeutic option for the patients with gallbladder cancer.     

KIF2 mediates the neuroprotection in cerebral ischaemia injury by affecting NF-κB pathway

Stroke is the most common cerebrovascular disease with high morbidity and mortality around the world. However, the underlying mechanisms involved in nerve injury and cerebral ischaemia/reperfusion (I/R) during cerebrovascular disease are still not completely clear. In the present study, we investigate the role of kinesin family member 2 (KIF2) in the neuroprotection after cerebral I/R injury. KIF2 was aberrantly expressed in the cerebral tissues from middle cerebral artery occlusion (MCAO) rat model in a time dependent manner. A similar changing pattern was found in the cultured hypoxic neurons as well as SK-N-SH cells in vitro. Compared to the control, KIF2 inhibition significantly increased the level of malonic dialdehyde (MDA), and reduced the level of superoxide dismutase (SOD) as well as glutathione peroxidase (GSH-px) activity in cerebral tissues of MCAO rat model. The reactive oxygen species (ROS) level was also up-regulated after KIF2 siRNA knockdown in cultured hypoxic SK-N-SH cells. The apoptosis rates of hypoxic neurons and SK-N-SH cells as well as activated-caspase-3 level were obviously increased after KIF2 silencing. Furthermore, we found that the nuclear factor-kappa B (NF-κB) pathway was involved in KIF2-mediated neuroprotection after cerebral I/R injury, and induced apoptosis of hypoxic SK-N-SH cells by KIF2 silencing could be attenuated by the specific inhibitor BAY11-7082 of NF-κB. In conclusion, we demonstrate that KIF2 could mediate the neuroprotection in cerebral I/R injury by inhibiting activation of NF-κB pathway. This might provide a novel therapeutic target for cerebral I/R injury.