Young-Gab Yun

Inhibitory effects of methanol extract of Cyperus rotundus rhizomes on nitric oxide and superoxide productions by murine macrophage cell line, RAW 264.7 cells.

The rhizomes of Cyperus rotundus (C. rotundus) have been used in oriental traditional medicines for the treatment of stomach and bowel disorders, and inflammatory diseases. Nitric oxide (NO) and superoxide (O2-) are important mediators in the pathogenesis of inflammatory diseases. This study was undertaken to address whether the metanol (MeOH) extract of rhizomes of C. rotundus could modulate NO and O2- productions by murine macrophage cell line, RAW 264.7 cells. The MeOH extract of rhizomes of C. rotundus showed the inhibition of NO production in a dose-dependent manner by RAW 264.7 cells stimulated with interferon-gamma plus lipopolysaccharide. The inhibition of NO production by the extract was due to the suppression of iNOS protein, as well as iNOS mRNA expression, determined by Western and Northern blotting analyses, respectively. In addition, the MeOH extract suppressed the production of O2- by phorbol ester-stimulated RAW 264.7 cells in dose- and time-dependent manners. Collectively, these results suggest that the MeOH extract of rhizomes of C. rotundus could be developed as anti-inflammatory candidate for the treatment of inflammatory diseases mediated by overproduction of NO and O2-.

Induction of granulocytic differentiation in acute promyelocytic leukemia cells (HL-60) by water-soluble chitosan oligomer.

Water-soluble chitosan oligomer (WSCO) has been reported to have anticancer activity, immuno-enhancing effect and antimicrobial activity. However, other biological activities are unknown. Herein, we have shown that WSCO is able to inhibit proliferation of human leukemia HL-60 cells and induce these cells to differentiate. Treatment with WSCO for 4 days resulted in a concentration-dependent reduction in HL-60 cell growth as measured by cell counting and MTT assay. This effect was accompanied by a marked increase in the proportion of G(0)/G(1) cells as measured by flow cytometry. WSCO also induced differentiation of the cells as measured by phorbol ester-dependent reduction of NBT, morphological changes as examined by Wright-Giemsa staining and expression of CD11b but not of CD14 as analysed by flow cytometry, indicating differentiation of HL-60 cells toward granulocyte-like cells. A combination of low dose of WSCO with all-trans retinoic acid, a differentiating agent toward granulocyte-like cells, exhibited a synergistic effect on the differentiation. In addition, treatment of HL-60 cells with WSCO for 6 or 8 days resulted in the induction of apoptosis as assayed qualitatively by agarose gel electrophoresis and quantitatively by Annexin V technique using flow cytometry. Collectively, there is a potential for WSCO in the treatment of myeloid leukemia.

Methanol extract of Cordyceps pruinosa inhibits in vitro and in vivo inflammatory mediators by suppressing NF-κB activation

Cordyceps pruinosa has been used in traditional folk medicine to treat numerous diseases. The molecular mechanism of C. pruinosa pharmacological and biochemical actions of macrophages in inflammation has not been clearly elucidated. We examined how the methanol extract of C. pruinosa regulates production of IL-1beta, TNF-alpha, nitric oxide (NO), and prostaglandin E(2) (PGE(2)) in vitro and in vivo. The extract inhibits these inflammatory mediators in LPS-stimulated murine macrophage cell line RAW264.7 and primary macrophages, by suppressing gene expression of IL-1beta, TNF-alpha, inducible nitric oxide synthase, and cyclooxygenase-2. Moreover, the extract suppresses the nuclear transcription factor NF-kappaB activation in LPS-stimulated RAW264.7 cells. Administration of the extract significantly decreases the plasma levels of these inflammatory mediators in LPS-injected mice. These results suggest that the C. pruinosa methanol extract suppresses inflammation through suppression of NF-kappaB-dependent inflammatory gene expression, suggesting that the C. pruinosa extract may be beneficial for treatment of endotoxin shock or sepsis.

In vitro anti-proliferative effect of 1,2,3,4,6-penta-O-galloyl-beta-D-glucose on human hepatocellular carcinoma cell line, SK-HEP-1 cells.

The root of Paeonia suffruticosa ANDREWS is an important Chinese crude drug used in many traditional prescriptions. 1,2,3,4,6-penta-O-galloyl-beta-D-glucose (PGG), a major component of this crude drug, was found to exhibit in vitro growth-inhibiting effect on human hepatocellular carcinoma cell line, SK-HEP-1 cells. The growth-inhibitory effect was related to the ability of PGG not only to cause a G(0)/G(1) phase arrest but also to suppress the activation of nuclear factor-kappa B. Neither apoptosis nor necrosis was observed in the cells treated with PGG. These findings suggest that PGG could be a candidate for developing a low-toxic anticancer agent.

Scoparone from Artemisia capillaris inhibits the release of inflammatory mediators in RAW 264.7 cells upon stimulation cells by interferon-γ 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-γ/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-γ/ LPS stimulated RAW 264.7 cells. Moreover, scoparone also attenuated the production of tumor necrosis factor (TNF)-α, interleukin (IL)-1β 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.

Ethyl acetate extract of the stem bark of Cudrania tricuspidata induces apoptosis in human leukemia HL-60 cells.

Apoptosis is now widely accepted as playing a role in tumorigenesis. An effective compound which can kill tumors via apoptotic pathway appears to be a relevant strategy to suppress various human tumors. The ethyl acetate extract from the stem bark of Cudrania tricuspidata (EACT) showed dose- and time-dependent cytotoxic effects on human leukemia HL-60 cells. DNA fragmentation and morphological changes, accompanied by condensed and fragmented nuclei, were observed in the cells cultured for 6 hr with EACT. These results suggest that the cytotoxicity of the crude extract from Cudrania tricuspidata against HL-60 cells is due to apoptosis.

Inhibitory effect of ethyl acetate fraction from Cudrania tricuspidata on the expression of nitric oxide synthase gene in RAW 264.7 macrophages stimulated with interferon-γ and lipopolysaccharide.

It was found that the production of nitric oxide (NO) by RAW 264.7 macrophages stimulated with interferon-gamma (IFN-gamma) and lipopolysaccharide (LPS) could be markedly inhibited by the ethyl-acetate-soluble fraction of 80% aqueous methanolic extract of stem barks of Cudrania tricuspidata (EACT). Inhibition of NO production was achieved by reducing inducible nitric oxide synthase (iNOS) expression at protein and mRNA levels and by inactivating nuclear factor-kappa B (NF-kappa B), but not by inhibiting iNOS activity. Thus, further phytochemical and pharmacological studies may lead to isolation and structural identification of an inhibitor of iNOS from C. tricuspidata, which has been used as a traditional medicine for curing inflammation.

Inhibitory Effects of Methanol Extract of Seeds of Job's Tears (Coix Lachryma-Jobi L Var. Ma-Yuen) On Nitric Oxide and Superoxide Production in Raw 264.7 Macrophages

Abstract Overproduction of nitric oxide (NO) or superoxide (O2) by activated macrophages is known to be involved in acute or chronic inflammation. The seeds of Jobs Tears (Coix lachryma-jobi L. var. ma-yuen) have been used as anti-inflammatory medicine and health food. However, it is still unclear how the seeds show anti-inflammatory properties. Using murine macrophage-like RAW 264.7 cells, we tried to know whether the overproduction of NO and O2 by activated macrophages could be prevented by the methanol (MeOH) extract of the seeds of Jobs Tears. RAW 264.7 cells were activated with interferon-γ plus lipopolysaccharide to produce NO and with pholbol ester to produce O2. The MeOH extract showed marked inhibition of NO production by activated RAW 264.7 cells in a dose-dependent manner via suppression of inducible NO synthase mRNA expression. The MeOH extract also showed inhibition of O2 production by activated RAW 264.7 cells in dose- and time-dependent manners, possibly by interfering with NADPH oxidase machinery of macrophages. Collectively, these results demonstrate that the MeOH extract of the seeds of Jobs Tears shows anti-inflammatory properties which may, in part, involve an inhibition of NO and O2 production by activated macrophages.

ERK MAP KINASE IS REQUIRED IN 1,25(OH)2D3-INDUCED DIFFERENTIATION IN HUMAN OSTEOBLASTS

ABSTRACT Expression of alkaline phosphatase(ALP)activity represents a key event during the differentiation processes of osteoblasts, and the level of ALP activity has been routinely used as a relative measure of differentiation stages of osteoblasts. In human osteoblasts, we showed that vitamin D3 analogue, 1,25(OH)2D3, had a stimulatory effect on ALP activity after 3 days, compared with control. The treatment of PD098059, an ERK MAP Kinase inhibitor, had a reducing effect on ALP activity, a differentiation marker in 1,25(OH)2D3-treated primary human osteoblasts. However, SB203580, a potent p38 MAP Kinase inhibitor, had no effect on the differentiation in this system. This indicates that ERK, not p38, is directly related to 1,25(OH)2D3 -stimulated ALP activity in primary human osteoblasts. These results also show that the vitamin D3 analogue stimulates ERK1 activation in primary human osteoblasts. This finding provides one of signaling pathways for differentiation in primary human osteoblasts.

Salidroside from Rhodiola sachalinensis Protects Neuronal PC12 Cells Against Cytotoxicity Induced by Amyloid‐β

Abstract The amyloid β‐peptide (Aβ)‐induced oxidative stress is a well‐established pathway of neuronal cell death in Alzheimers disease (AD). Salidroside, one of the major compounds from the roots of Rhodiola species (Crassulaceae), was investigated in vitro for its cytoprotection against Aβ‐induced toxicity on rat neuronal PC12 cells. Salidroside significantly reduced Aβ‐induced cytotoxicity in a dose‐dependent manner. Salidroside also reduced Aβ‐mediated intracellular accumulation of reactive oxygen species and malondialdehyde (MDA), a product of lipid peroxides, by preventing Aβ‐induced decline of antioxidant enzyme activities. These results suggest that salidroside protects neuronal PC12 cells from Aβ‐induced cytotoxicity via its antioxidant pathway.