氯化镧拮抗内毒素作用的初步研究

用定量鲎基质显色法测定LaCl3结合内毒素（LPS）的能力。通过ELISA，荧光宣RT－PCR方法观察LaCl3对LPS诱导的小鼠腹腔巨噬细胞（Mψ）肿瘤坏死因子－α（TNF－α）分泌及TNF－αmRNA表达的影响。通过小鼠死亡观察LaCl3和LPS毒性的影响。结果显示LaCl3具有结合LPS，抑制TNF－α分泌及TNF－αmRNA表达，降低LPS毒性的作用。     

Removal of lipopolysaccharide and reactive oxygen species using sialic acid immobilized polysulfone dialyzer

Sialic acid (N‐acetylneuraminic acid, NANA) was covalently immobilized onto the surface of a polysulfone (PSF) hollow fiber membrane. Prior to the immobilization, the surface of PSF was treated with ozone, followed by grafting with acrylic acid, and then the esterification of NANA. The surface concentration of NANA was determined by 2‐thiobarbituric acid (TBA) test. Hemocompatibility, the capability of suppressing oxidative stress, and clearance of lipopolysaccharide (LPS) from the resulting hollow fiber membrane were evaluated. The results show that by immobilizing NANA onto PSF hollow fiber, the adhesion of platelet was reduced, while both APTT and PT were little affected. Furthermore, oxidative stress was suppressed by NANA‐immobilized PSF hollow fibers. The level of LPS was also greatly reduced. Copyright © 2009 John Wiley & Sons, Ltd.     

Disruption of lipid rafts impairs the production of nitric oxide in lipopolysaccharide-stimulated murine RAW264.7 macrophages

Upon stimulation with lipopolysaccharide, murine RAW264.7 macrophages generated a high amount of nitric oxide. Pretreatment of macrophages with methyl-β-cyclodextrin, which disrupted the lipid raft microdomains of the plasma membrane, inhibited the generation of nitric oxide by down-regulating the expression of inducible nitric oxide synthase. Methyl-β-cyclodextrin exposure significantly inhibited the degradation of IκB-α, blocked the translocation of p65/RelA into the nuclei and prevented the activation of the NF-κB signaling pathway. The results suggest that the expression of inducible nitric oxide synthase and the consequent production of nitric oxide depend on the integrity of the lipid rafts.     

Inhibitory Effects of 2,6-Di-O-methyl-3-O-acetyl-β-cyclodextrins with Various Degrees of Substitution of Acetyl Group on Macrophage Activation and Endotoxin Shock Induced by Lipopolysaccharide

The effects of 2,6-di-O-methyl-3-O-acetyl-β-cyclodextrins (DMA-β-CyD) with various degrees of substitution (DS) of an acetyl group of 1.5, 3.8, 6.3 and 7, which are abbreviated to DMA2-β-CyD, DMA4-β-CyD, DMA6-β-CyD and DMA7-β-CyD, respectively, on murine macrophage activation and endotoxin shock induced by lipopolysaccharide (LPS) were examined. Of four DMA-β-CyDs used in the present study, cytotoxicity of DMA-β-CyDs in RAW264.7 cells, a murine macrophage-like cell line, decreased with an increase in the DS values of DMA-β-CyD, and DMA7-β-CyD had no cytotoxicity on RAW264.7 cells up to 100 mM. DMA2-β-CyD and DMA7-β-CyD at the concentration of 5 mM had greater inhibitory effects on nitric oxide (NO) production in RAW264.7 cells stimulated with LPS than DMA4-β-CyD and DMA6-β-CyD. In addition, these inhibitory effects of DMA2-β-CyD and DMA7-β-CyD were concentration-dependent. In the in vivo study, all of the mice died within 12 h after intraperitoneal administration of the solution containing LPS and d-galactosamine. When 100 mM DMA7-β-CyD was concomitantly administered with both LPS and d-galactosamine intraperitoneally in mice, the survival rate significantly increased, but DMA4-β-CyD and DMA6-β-CyD did not. In conclusion, we revealed that DS values of DMA-β-CyDs strikingly affect not only the cytotoxic activity but also the inhibitory effects of LPS-induced NO production in RAW264.7 cells and fatality of endotoxin shock mice induced by LPS and d-galactosamine. These results suggest the potential use of DMA7-β-CyD as an antagonist of LPS-induced endotoxin shock.     

Berberine,A Phytoalkaloid,Inhibits Inflammatory Response Induced by LPS through NF-Kappaβ Pathway: Possible Involvement of the IKKα

Berberine (BBR), a plant alkaloid, is known for its therapeutic properties of anticancer, cardioprotective, antidiabetic, hypolipidemic, neuroprotective, and hepatoprotective activities. The present study was to determine the molecular mechanism of BBR’s pharmacological activity in human monocytic (THP-1) cells induced by arachidonic acid (AA) or lipopolysaccharide (LPS). The effect of BBR on AA/LPS activated proinflammatory markers including TNF-α, MCP-1, IL-8 and COX-2 was measured by ELISA or quantitative real-time PCR. Furthermore, the effect of BBR on LPS-induced NF-κB translocation was determined by immunoblotting and confocal microscopy. AA/ LPS-induced TNF-α, MCP-1, IL-6, IL-8, and COX-2 markers were markedly attenuated by BBR treatment in THP-1 cells by inhibiting NF-κB translocation into the nucleus. Molecular modeling studies suggested the direct interaction of BBR to IKKα at its ligand binding site, which led to the inhibition of the LPS-induced NF-κB translocation to the nucleus. Thus, the present study demonstrated the anti-inflammatory potential of BBR via NF-κB in activated monocytes, whose interplay is key in health and in the pathophysiology of atherosclerotic development in blood vessel walls. The present study findings suggest that BBR has the potential for treating various chronic inflammatory disorders.     

Recognition of lipopolysaccharide pattern by TLR4 complexes

Lipopolysaccharide (LPS) is a major component of the outer membrane of Gram-negative bacteria. Minute amounts of LPS released from infecting pathogens can initiate potent innate immune responses that prime the immune system against further infection. However, when the LPS response is not properly controlled it can lead to fatal septic shock syndrome. The common structural pattern of LPS in diverse bacterial species is recognized by a cascade of LPS receptors and accessory proteins, LPS binding protein (LBP), CD14 and the Toll-like receptor4 (TLR4)–MD-2 complex. The structures of these proteins account for how our immune system differentiates LPS molecules from structurally similar host molecules. They also provide insights useful for discovery of anti-sepsis drugs. In this review, we summarize these structures and describe the structural basis of LPS recognition by LPS receptors and accessory proteins.     

Optimization of extraction process of Dioscorea nipponica Makino saponins and their UPLC-QTOF-MS profiling,antioxidant, antibacterial and anti- inflammatory activities

Dioscorea nipponica Makino exhibits many biological activities, including relieving cough, eliminating phlegm and preventing asthma. The present study extensively evaluated the extraction process, major components, antioxidant, antibacterial and anti-inflammatory activities of total saponins extraction from Dioscorea nipponica Makino. In this study, the optimal extraction process of total saponins extract was optimized by single-factor test and response surface methodology as follows: extraction time 25 min, ethanol concentration 50 % and liquid to material ratio 55:1 ml/g, and the extraction rate was 1.72 %. Eighteen components were initially analyzed by UPLC-QTOF-MS method. Although total saponins extract exhibited mild antibacterial activities against Escherichia coli, Salmonella, Staphylococcus aureus and Streptococcus, and antioxidant activities against ferric-ion, ABTS and DPPH radicals, the perfect anti-inflammatory activity of TSE was demonstrated by significantly reducing the content of NO and the phagocytic activity in LPS induced RAW 264.7 cells, which provided a theoretical basis for the research and development of new anti-inflammatory Chinese medicine.     

Detection of LPS-induced macrophage activation with single-cell resolution through DC insulator-based electrokinetic devices

Macrophages are considered critical in the initiation, maintenance, and resolution of inflammation. Lipopolysaccharide (LPS)-induced inflammation is often used as a model to understand the cell inflammation responses. Current techniques identifying the LPS-induced inflammation are experiencing cell destruction or cell labeling or are based on the whole cell population information with low identification degree. This limits the detection process with time-consuming cytokine selection, low resolution of population heterogeneity, and unavailability for their next use. Direct current insulator-based electrokinetics (DC-iEK) is introduced to achieve an easier and noninvasive identification of inflamed cells with high resolution. A biophysical scale is also established first time for screening medicine in the treatment of inflammation. The new microfluidic design concentrates cells with applied voltages forming streamline providing more stable cell capture conditions and unique biophysical factors at different capture positions. The average electric field of the cell capture positions is recorded to characterize each cell population. The characterization value of macrophage decreases from to 1.61 × 10⁴ V/m when treated with 0.1 mM LPS and to 1.42 × 10⁴ V/m when treated with 1 mM LPS. By treating the inflamed macrophages with representative effective medicines, healing signals could also be detected by a newly established inflammation scale. The cells showed proliferation and functional activity after extraction. DC-iEK has provided an easy and noninvasive approach to identify inflammation for further fundamental and clinical precision medicine use.     

Foodomics revealed the effects of ultrasonic extraction on the composition and nutrition of cactus fruit (Opuntia ficus-indica) seed oil

Cactus is a tropical fruit with a high nutritional value; however, little information is available regarding the comprehensive utilization of its byproducts. This study aimed to explore the composition and nutritional value of cactus fruit seed oil (CFO) and reveal the effects of ultrasound-assisted extraction and traditional solvent extraction on oil quality. Foodomics analysis showed that CFO extracted using a traditional solvent is rich in linolenic acid (9c12cC18:2, 57.46 ± 0.84 %), α-tocopherol (20.01 ± 1.86 mg/100 g oil), and canolol (200.10 ± 1.21 μg/g). Compared to traditional solvent extraction, ultrasound-assisted extraction can significantly increase the content of lipid concomitants in CFO, whereas excessive ultrasound intensity may lead to the oxidation of oils and the formation of free radicals. Analysis of the thermal properties showed that ultrasound had no effect on the crystallization or melting behavior of CFO. To further demonstrate the nutritional value of CFO, a lipopolysaccharide (LPS)-induced lipid metabolism imbalance model was used. Lipidomics analysis showed that CFO significantly reduced the content of oxidized phospholipids stimulated by LPS and increased the content of highly bioactive metabolites such as ceramides, thus alleviating LPS-induced damage in C. elegans. Hence, CFO is a functional oil with high value, and ultrasound-assisted extraction is advocated. These findings provide new insights into the comprehensive utilization of cactus fruits.