Anti-inflammatory effects of Dendrobium nobile derived phenanthrenes in LPS-stimulated murine macrophages.

Dendrobium nobile belongs to the Orchidaceae family and is one of the medicinal herbs used in traditional Chinese medicine as a therapeutic agent for gastrointestinal and cardiovascular diseases. In this study, we separated three phenanthrenes (ephemeranthol A (EA), 1,5,7-trimethoxyphenanthren-2-ol (TP), dehydroorchinol (DO)) from D. nobile, and compared their anti-inflammatory activities. TP is a new phenanthrene compound and its structure was determined from (1)H, (13)C NMR and HR-ESI-MS data. To analyze the anti-inflammatory activities of the phenanthrenes, Raw 264.7 cells were used, since they are immature-macrophages and easily matured by LPS stimulation. EA and DO showed anti-inflammatory activities in the activated Raw 264.7 cells. That is, we showed that EA is a potent inhibitor of the production of nitric oxide and pro-inflammatory cytokines. The inhibitory activities of phenanthrenes were found to be caused by blockage of NF-κB activation and the phosphorylation of MAP kinases in the macrophages. These results are expected to serve as a guide for future studies on the ability of phenanthrenes to inhibit acute and chronic inflammatory diseases.

Anti-inflammatory effects of dehydrogeijerin in LPS-stimulated murine macrophages.

In this study, we investigated whether Heracleum (H) moellendorffii Hance-derived dehydrogeijerin and geijerin could be used to suppress lipopolysaccharide (LPS)-induced inflammatory responses in murine macrophage cell lines, Raw 264.7 cells. Dehydrogeijerin reduced nitric oxide (NO) and inducible nitric oxide synthase (iNOS) production from LPS-stimulated Raw 264.7 cells, but on the other hand, geijerin did not reduce NO production. Dehydrogeijerin, unlike geijerin, has a double bond at C2'-C3' with an oxo function at C1'. Pre-treatment of Raw 264.7 cells with dehydrogeijerin reduced the production of cyclooxigenase-2 (COX-2) and pro-inflammatory cytokines. These inhibitory effects were associated with decreases in the phosphorylation of mitogen-activated protein (MAP) kinases. Our results indicate that dehydrogeijerin significantly inhibits the inflammatory activity of activated macrophages, suggesting that dehydrogeijerin could be a potential candidate for the treatment of inflammatory disease.

A polyacetylene from Gymnaster koraiensis exerts hepatoprotective effects in vivo and in vitro.

In the present study, we isolated a polyacetylene, gymnasterkoreayne B (GKB), from Gymnaster koraiensis and investigated the effect of GKB on the protection from oxidative stress-induced cytotoxicity through induction of the expression of cellular defense enzymes. GKB induced mRNA expression and enzyme activity of NAD(P)H:quinone oxidoreductase (NQO1) in vitro and in vivo, and potently increased expression of many cellular defense genes including glutathione-S-transferases, UDP-glucuronosyltransferase, and glutathione reductase (GSR) in normal rat liver. The nuclear factor erythroid 2-related factor 2 (Nrf2) which is known to induce various antioxidant and cytoprotective genes, and the genes containing the antioxidant response element (ARE), including NQO1, hemeoxygenease-1, GSR were induced by GKB in HepG2 human hepatocarcinoma cells. Pre-treatment of the cells with GKB accelerated the production of glutathione and mitigated menadione-induced cytotoxicity in HepG2 cells. Taken together, we found that GKB was a novel inducer of phase II detoxification enzymes and cellular defense enzymes, resulting in protection of the cells from oxidative stress and hepatotoxicity through regulation of detoxifying and antioxidant systems.

Anti-inflammatory effects of gomisin N, gomisin J, and schisandrin C isolated from the fruit of Schisandra chinensis.

Schiandra chinensis is a well-known Chinese traditional medicine for the treatment of hepatic disease. In this study, we investigated whether the nine major compounds of Schiandra chinensis could be applied to suppress lipopolysaccharide (LPS)-induced inflammatory responses in murine macrophages (Raw 264.7 cells). Among the nine lignans, three, gomisin J, gomisin N, and schisandrin C, were found to reduce nitric oxide (NO) production from LPS-stimulated Raw 264.7 cells. These three lignans showed low cytotoxic effects in Raw 264.7 cells. Pre-treatment of Raw 264.7 cells with gomisin J, gomisin N, or schisandrin C reduced the expression of mRNA and the secretion of pro-inflammatory cytokines. These inhibitory effects were found to be caused by blockage of p38 mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinases 1 and 2 (ERK 1/2), and c-Jun N-terminal kinase (JNK) phosphorylation.

Tectorigenin inhibits IFN-gamma/LPS-induced inflammatory responses in murine macrophage RAW 264.7 cells.

Tectorigenin (Tg) and tectoridin (Td) are the major compounds isolated from the rhizomes of iridaceous plant Belamcanda chinensis which is well known as a chinese traditional medicine for the treatment of inflammatory diseases. In this study we investigated whether tectorigenin and tectoridin can be applied to the suppression of interferon-gamma and lipopolysaccharide (IFN-gamma/LPS)-induced inflammatory responses in macrophages. Anti-inflammatory activities of tectorigenin and tectoridin were compared with genistein (Ge), well known isoflavonoid as a phytoestrogen and regarded as an emerging anti-inflammatory agent. Both compounds showed low cytotoxic effect. In Raw 264.7 cells activated with IFN-gamma/LPS, pre-treated tectorigenin was found to inhibit the expression of inducible nitric oxide synthase (iNOS), the production of nitric oxide (NO) and the secretion of interleukin (IL)-1beta dose-dependently. Tectorigenin also decreased the expression of cyclooxigenase (COX)-2 and the production of prostaglandin E(2) (PGE(2)) in dose-dependent manner. These inhibitory effects of tectorigenin were found to be caused by the blocking of nuclear factor kappa-B (NF-kappaB) activation. Compared with genistein and tectoridin, tectorigenin showed significant inhibitory effect for almost anti-inflammatory tests in this study. All these results clearly demonstrated that tectorigenin appears to have the potential to prevent inflammation.

Biotransformation of Korean Panax ginseng by Pectinex.

Ginsenosides comprise the major component of ginseng exhibit various types of biological activity, including antiinflammatory and antitumor effects. In these pharmacological actions, it is thought that these activities are carried out by the metabolites of ginsenosides metabolized by human intestinal microflora. It has also been reported that their clinical efficacy varies with the hydrolyzing potential of the components of the intestinal microflora. We tried to develop a process for metabolizing ginsenosides to compound K using food-grade enzymes, which can be used commercially. Among these, Pectinex proved to be the most effective mediator of the catabolism of ginsenosides to compound K. The optimal conditions for this biotransformation were determined to be as follows: 10 to 15% rootlet ginseng, pH 5, 50 degrees C, and 2 to 3 d of incubation, to yield 20.0 mg of compound K/g of rootlet ginseng. We suggest that the metabolism of ginseng to compound K in the presence of Pectinex has many advantages over previous methods, in respects of use of raw, non-extracted rootlet ginseng, which do not require more organic solvents and evaporation apparatus. Potential metabolites PG1, PG2, PG3, and PG4 were detected in Pectinex-treated rootlet ginseng using by TLC and HPLC and, among them, PG4 was identified as compound K by TLC, HPLC, and MS. Additional studies will be carried out to determine the structure of these metabolites of ginseng and to understand the relationship between their structures and activities.

Differences in signaling pathways by IL-1beta and IL-18.

IL-1 and IL-18 are members of the IL-1 family of ligands, and their receptors are members of the IL-1 receptor family. Although several biological properties overlap for these cytokines, differences exist. IL-18 uniquely induces IFN-gamma from T lymphocytes and natural killer cells but does not cause fever, whereas fever is a prominent characteristic of IL-1 in humans and animals. In the present study, human epithelial cells were stably transfected with the IL-18 receptor beta chain and responded to IL-18 with increased production of IL-1alpha, IL-6, and IL-8. Five minutes after exposure to either cytokine, phosphorylation of mitogen activated protein kinase (MAPK) p38 was present; specific inhibition of p38 MAPK reduced IL-18 activity to background levels. Whereas IL-1beta induced the expression of the NF-kappaB-reporter gene and was suppressed by competitive inhibition of NF-kappaB binding, IL-18 responses were weak or absent. In contrast to IL-1beta, IL-18 also did not activate degradation of the NF-kappaB inhibitor. After 4 h, both cytokines induced comparable levels of mRNA for the chemokine IL-8 but, in the same cells, steady-state levels of cyclooxygenase (COX)-2 mRNA were high after IL-1beta but low or absent after IL-18. After 30 h, IL-18-induced COX-2 appeared in part to be IL-1 dependent. Similarly, low levels of prostaglandin E2 were measured in IL-18-stimulated A549 cells and freshly obtained primary human monocytes and mouse macrophages. We conclude that in epithelial cells, IL-18 signal transduction is primarily via the MAPK p38 pathway rather than NF-kappaB, which may explain the absence of COX-2 and the failure of IL-18 to cause fever.