Effect Of Raw Research Articles

Inhibitory effects of constituents from Morus alba var. multicaulis on differentiation of 3T3-L1 cells and nitric oxide production in RAW264.7 cells.

A new arylbenzofuran, 3′,5′-dihydroxy-6-methoxy-7-prenyl-2-arylbenzofuran (1), and 25 known compounds, including moracin R (2), moracin C (3), moracin O (4), moracin P (5), artoindonesianin O (6), moracin D (7), alabafuran A (8), mulberrofuran L (9), mulberrofuran Y (10), kuwanon A (11), kuwanon C (12), kuwanon T (13), morusin (14), kuwanon E (15), sanggenon F (16), betulinic acid (17), uvaol (18), ursolic acid (19), β-sitosterol (20), oxyresveratrol 2-O-β-d-glucopyranoside (21), mulberroside A (22), mulberroside B (23), 5,7-dihydroxycoumarin 7-O-β-d-glucopyranoside (24), 5,7-dihydroxycoumarin 7-O-β-d-apiofuranosyl-(1→6)-O-β-d-glucopyranoside (25) and adenosine (26), were isolated from Morus alba var. multicaulis Perro. (Moraceae). Their structures were determined by spectroscopic methods. The prenyl-flavonoids 11–14, 16, triterpenoids 17,18 and 20 showed significant inhibitory activity towards the differentiation of 3T3-L1 adipocytes. The arylbenzofurans 1–10 and prenyl-flavonoids 11–16 also showed significant nitric oxide (NO) production inhibitory effects in RAW264.7 cells.

A potent sphingomyelinase inhibitor from Cordyceps mycelia contributes its cytoprotective effect against oxidative stress in macrophages

A novel water-soluble polysaccharide fraction, CME-1, with a molecular mass of 27.6 kDa and containing mannose and galactose in a respective ratio of 4:6, was prepared from Cordyceps sinensis mycelia and identified by NMR and GC-MS. In the current study, we examined whether CME-1 has anti-inflammatory effects in RAW264.7 cells. The ability of CME-1 to inhibit H(2)O(2)-induced cell death in RAW264.7 cells was assessed by using an MTT assay and annexin V/propidium iodide double staining; we found that CME-1 protected cells against H(2)O(2)-induced injury. H(2)O(2)-induced intracellular oxidative stress and mitochondrial membrane depolarization were also diminished with CME-1 treatment. We evaluated the hydroxyl radical scavenging ability of CME-1 by using the DMPO-electron spin resonance technique, which indicated that CME-1 acts as an intracellular antioxidant in a concentration-dependent manner through a mechanism other than its scavenging activity. Activities of both neutral and acid sphingomyelinases (SMases) were assessed in vitro, and results showed that the CME-1 inhibited activities of both neutral and acid SMases in a concentration-dependent manner. CME-1 reduced H(2)O(2) treatment-elevated C16- and C18-ceramide levels measured by LC/MS/MS in RAW264.7 cells. Results suggest that CME-1 protects RAW264.7 cells against oxidative stress through inhibition of SMase activity and reduction of C16- and C18-ceramide levels.

Heparin changes the conformation of high-mobility group protein 1 and decreases its affinity toward receptor for advanced glycation endproducts in vitro

High-mobility group protein 1 (HMGB1) has been identified as a late-acting mediator of inflammation. The receptor for advanced glycation end products (RAGE) is the main receptor and mediates the cytokine activity of HMGB1. Since HMGB1 also exhibits heparin-binding activity, we investigated whether heparin interferes with HMGB1/RAGE interaction and prevents the cytokine activity. We used fluorescence spectrometry, circular dichroism spectrometry and SPR biosensor technique to evaluate the effect. After treatment of HMGB1 with different concentrations of heparin (0, 50, 100 and 1000U/L), the fluorescence peak values of HMGB1 increased and the emission wavelength showed red shifts; further, the secondary structure of HMGB1 showed a marked change in that the content of β-pleated sheet reduced while that of α-helix increased. The equilibrium dissociation constants (KD) were determined by SPR technique; KD=4.5×10−9mol/L for heparin and HMGB1 and KD=9.77×10−8mol/L for HMGB1 and RAGE, respectively. Heparin and RAGE had no interaction. The amount of HMGB1 and RAGE bound forms reduced after treatment with heparin. ELISA revealed that addition of heparin inhibited the TNF-α and IL-6 released by macrophages RAW264.7 and HUVEC; 10U/L and 50U/L of heparin showed the most marked inhibitory effect in RAW264.7 cells and in HUVEC, respectively. In conclusion, heparin can combine with HMGB1 and affect the affinity of HMGB1/RAGE by changing the conformation of HMGB1. And this effect was independent of heparin concentration, so that a low dose of heparin was sufficient to achieve the best anti-inflammatory effect in our test.

Quercetin, but not rutin and quercitrin, prevention of H 2O 2-induced apoptosis via anti-oxidant activity and heme oxygenase 1 gene expression in macrophages

In the present study, we examine the protective mechanism of quercetin (QE) on oxidative stress-induced cytotoxic effect in RAW264.7 macrophages. Results of Western blotting show that QE but not its glycoside rutin (RUT) and quicitrin-induced HO-1 protein expression in a time- and dose-dependent manner, and HO-1 protein induced by QE was blocked by an addition of cycloheximide or actinomycin D. Induction of HO-1 gene expression by QE was accompanied by inducing ERKs, but not JNKs or p38, proteins phosphorylation. Addition of PD98059, but not SB203580 or SP600125, significantly attenuates QE-induced HO-1 protein and mRNA expression associated with blocking the expression of phosphorylated ERKs proteins. H 2O 2 addition reduces the viability of cells by MTT assay, and appearance of DNA ladders, hypodiploid cells, and an increase in intracellular peroxide level was detected. Addition of QE, but not QI or RUT, significantly reduced the cytotoxic effect induced by H 2O 2 associated with blocking the production of intracellular peroxide, DNA ladders, and hypodiploid cells. QE protection of cells from H 2O 2-induced apoptosis was significantly suppressed by adding HO inhibitor SnPP or ERKs inhibitor PD98059. Additionally, QE protects cells from H 2O 2-induced a decrease in the mitochondrial membrane potential and a release of cytochrome c from mitochondria to cytosol by DiOC6 and Western blotting assay, respectively. Activation of apoptotic proteins including the caspase 3, caspase 9, PARP, D4-GDI proteins was identified in H 2O 2-treated cells by Western blotting and enzyme activity assay, and that was significantly blocked by an addition of QE, but not RUT and QI. Furthermore, HO-1 catalytic metabolites carbon monoxide (CO), but not Fe 2+, Fe 3+, biliverdin or bilirubin, performed protective effect on cells from H 2O 2-induced cell death with an increase in HO-1 protein expression and ERKs protein phosphorylation. These data suggest that induction of HO-1 protein may participate in the protective mechanism of QE on oxidative stress (H 2O 2)-induced apoptosis, and reduction of intracellular ROS production and mitochondria dysfunction with blocking apoptotic events were involved. Differential anti-apoptotic effect between QE and its glycosides RUT and QI via distinct HO-1 protein induction was also delineated.

Effect of wood acidity and catalyst on UF resin gel time

Abstract Knowledge of pH and buffering capacity of raw fiber materials is important for understanding the effects of raw material on the curing rate of urea formaldehyde (UF) resin, used for panel manufacturing, especially with some less-desirable wood materials such as bark, top, and commercial thinnings. The effects of pH and buffering capacity as well as catalyst content on the gel time of UF resin were investigated. The results obtained from this study indicate that bark has a lower pH value as well as higher acid and alkaline buffering capacities than wood of the same species due to their extractives. The pH values of the raw fiber materials studied decrease with increased absolute and relative acid buffering capacity due to the increased absolute acidity mass in the solution. At lower levels of added catalyst, the effect of raw material pH on UF resin gel time is significant, while it is insignificant at higher catalyst contents. This may be due to the acidity of wood, which is the main acid catalyst source of the mixture at lower levels of added catalyst, while at higher levels, catalyst is the main source. With higher catalyst contents, all studied raw materials mixed with UF resin result in a longer gel time than does UF resin alone.