Inhibitory effect of dibutyryl chitin ester on nitric oxide and prostaglandin E2 production in LPS-stimulated RAW 264.7 cells.

Inflammation is a highly complex process that protects against foreign challenge or tissue injury. The ester derivative dibutyryl chitin (DBC) reportedly accelerates wound healing and exerts an anti-inflammatory effect. However, little is known regarding the inhibitory effect of DBC in anti-inflammation. In this study, we investigated the effect of DBC on the inducible nitric oxide synthetase (iNOS) and cyclooxygenage-2 (COX-2) pathways and pro-inflammatory cytokine production in lipopolysaccharide (LPS)-treated RAW 264.7 macrophages. Our results demonstrate that DBC (MW 3,772) significantly inhibits overproduction of NO and PGE(2) as well as pro-inflammatory cytokines, such as tumor necrosis factor-α and interleukin-1ß, in LPS-stimulated RAW 264.7 macrophages. Inhibition of NO and PGE(2) overproduction in LPSstimulated RAW 264.7 macrophages by DBC was mediated through the down-regulation of iNOS and COX-2 expression. These results demonstrate that DBC efficiently inhibits inflammation and has potential as an effective anti-inflammatory and wound healing agent.

The combination of berberine and irradiation enhances anti-cancer effects via activation of p38 MAPK pathway and ROS generation in human hepatoma cells.

Berberine, an isoquinoline plant alkaloid, has been known to generate a wide variety of biochemical and pharmacological effects. In order to elucidate the molecular mechanism for the berberine-induced enhancement of radio-sensitization, the human hepatoma HepG2 cells were treated with berberine combined with irradiation. The anti-tumor effect of gamma radiation was found to be significantly enhanced by berberine. The evidences of apoptosis, such as apoptotic DNA fragmentation and annexin V staining, were observed in the cells treated with the combination of berberine and irradiation. Additionally, the levels of reactive oxygen species (ROS) and nitric oxide (NO) were apparently elevated in the combination system. The activations of p38, Bax, and caspase-3 were also detected in the irradiated cells pretreated with berberine. The productions of ROS and annexin V staining in the cells treated with the combination of berberine and irradiation were significantly inhibited by the specific inhibitor of p38 MAPK, SB203580. The cell death induced by berberine alone or the combination of berberine and irradiation was suppressed by the anti-oxidant, N-acetyl cysteine (NAC). Taken together, the present results clearly indicate that the combination of berberine and gamma-radiation enhance the anti-cancer effects through the p38 MAPK pathway and ROS generation.

Gliotoxin enhances radiotherapy via inhibition of radiation-induced GADD45a, p38, and NFkappaB activation.

The purpose of the study was to elucidate the mechanism underlying the enhancement of radiosensitivity to 60Co gamma-irradiation in human hepatoma cell line HepG2 pretreated with gliotoxin. Enhancement of radiotherapy by gliotoxin was investigated in vitro with human hepatoma HepG2 cell line. Apoptosis related proteins were evaluated by Western blotting. Annexin V/PI and reactive oxygen species (ROS) were quantified by Flow Cytometric (FACS) analysis. Gliotoxin (200 ng/ml) combined with radiation (4 Gy) treated cells induced apoptosis. Cells treated with gliotoxin (200 ng/ml) prior to irradiation at 4 Gy induced the expression of bax and nitric oxide (NO). The gliotoxin-irradiated cells also increased caspase-3 activation and ROS. Gadd45a, p38, and nuclear factor kappa B (NFkappaB) activated in irradiated cells was inhibited by Gliotoxin. Specific inhibitors of p38 kinase, SB203580, significantly inhibited NFkappaB activation and increased the cytotoxicity effect in cells exposed to gliotoxin combined with irradiation. However, SB203580 did not suppress the activation of Gadd45a in irradiated cells. Gliotoxin inhibited anti-apoptotic signal pathway involving the activation of Gadd45a-p38-NFkappaB mediated survival pathway that prevent radiation-induced cell death. Therefore, gliotoxin, blocking inflammation pathway and enhancing irradiation-induced apoptosis, is a promising agent to increase the radiotherapy of tumor cells.

InhA-like protease secreted by Bacillus sp. S17110 inhabited in turban shell.

A strain producing a potent protease was isolated from turban shell. The strain was identified as Bacillus sp. S17110 based on phylogenetic analysis. The enzyme was purified from culture supernatant of Bacillus sp. S17110 to homogeneity by ammonium sulfate precipitation, SP-Sepharose, and DEAE-Sepharose anion exchange chromatography. Protease activity of the purified protein against casein was found to be stable at pH 7 to pH 10 and around 50 degrees . Approximately 70% of proteolytic activity of the enzyme was detected either in the presence of 100 mM SDS or Tween 20. The enzyme activity was enhanced in the presence of Ca2+, Zn2+, Mg2+, but was inhibited by EDTA, indicating that it requires metal for its activity. The purified enzyme was found to be a monomeric protein with a molecular mass of 75 kDa, as estimated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and gel filtration chromatography. The purified enzyme was analyzed through peptide fingerprint mass spectra generated from matrix-assisted laser desorption ionization-time-of-flight-mass spectrometry (MALDI-TOF-MS) and a BLAST search, and identified as immune inhibitor A (inhA) deduced from nucleotide sequence of B. cereus G9241. Since InhA was identified as protease that cleave antibacterial proteins found in insect, inhA-like protease purified from Bacillus sp. S17110 might be pathogenic to sea invertebrates.

Scoparone from Artemisia capillaris inhibits the release of inflammatory mediators in RAW 264.7 cells upon stimulation cells by interferon-gamma Plus LPS.

Scoparone is a major component of the shoot of Artemisia capillaris (Compositae), which has been used for the treatment of hepatitis and biliary tract infection in oriental countries. In the present study we observed that, scorparone exhibited no cytotoxic effect in unstimulated macrophages, but reduced the release of nitric oxide (NO) and prostaglandin E2 (PGE2) upon stimulation by IFN-gamma/LPS or LPS. The inhibitory effects were found to be in conjuction with the suppression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in IFN-gamma/LPS stimulated RAW 264.7 cells. Moreover, scoparone also attenuated the production of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta and IL-6 in LPS-stimulated RAW264.7 cells. These results suggest that scoparone decreases the production of the inflammatory mediators such as NO and PGE2 in macrophages by inhibiting iNOS and COX-2 expression.

Stylopine from Chelidonium majus inhibits LPS-induced inflammatory mediators in RAW 264.7 cells.

Stylopine is a major component of the leaf of Chelidonium majus L. (Papaveraceae), which has been used for the removal of warts, papillomas and condylomas, as well as the treatment of liver disease, in oriental countries. Stylopine per se had no cytotoxic effect in unstimulated RAW 264.7 cells, but concentration-dependently reduced nitric oxide (NO), prostaglandin E2 (PGE2), tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta), and the IL-6 production and cyclooxygenase-2 (COX-2) activity caused by the LPS stimulation. The levels of inducible nitric oxide synthase (iNOS) and COX-2 protein expressions were markedly suppressed by stylopine in a concentration dependent manner. These results suggest that stylopine suppress the NO and PGE2 production in macrophages by inhibiting the iNOS and COX-2 expressions. These biological activities of stylopine may contribute to the anti-inflammatory activity of Chelidonium majus.