Shinha Han

Immunomodulatory activity of betulinic acid by producing pro-inflammatory cytokines and activation of macrophages.

Betulinic acid (BA), a pentacyclic triterpene isolated fromLycopus lucidus, has been reported to be a selective inducer of apoptosis in various human cancer and shown anti-inflammatory and immunomodulatory properties. We postulated that BA modulates the immunomodulatory properties at least two groups of protein mediators of inflammation, interlukin-1β (IL-1β) and the tumor necrosis factor-a (TNF-α) on the basis of the critical role of the monocytes and tissue macrophages in inflammatory and immune responses. TNF-α and IL-1β were produced by BA in a dose dependent manner at concentration of 0.625 and 10 μg/mL. The production of NO associated withiNOS was inhibited when treated with LPS at the concentration of 2.5 to 20 μg/mL of BA whereas COX-2 expression was decreased at 2.5 to 20 μg/mL. These modulations of inflammatory mediators were examined in LPS-stimulated RAW 264.7 cells and peritoneal macrophages. The morphology of macrophage was also examined and enhanced surface CD 40 molecule was expressed when treated BA at 0.625–5 ¼g/mL with or without LPS. Furthermore, BA (20 μg/mL) enhanced apoptosis by producing DNA ladder in the RAW 264.7 cells. Our results indicated that BA induced activation of macrophage and pro-inflammatory cytokines. This may provide a molecular basis for the ability of BA to mediate macrophage, suppress inflammation, and modulate the immune response.

Anti-inflammatory function of arctiin by inhibiting COX-2 expression via NF-κB pathways

BackgroundArctiin, isolated from Forsythia suspensa has been reported to have anti-inflammatory, anti-oxidant, antibacterial, and antiviral effects in vitro. However, there has been a lack of studies regarding its effects on immunological activity. The aim of this study is to investigate the anti-inflammatory potential and possible mechanisms of arctiin in LPS-induced macrophages.MethodsWe investigated the mRNA and protein levels of proinflammatory cytokines through RT-PCR and western blot analysis, followed by a FACS analysis for surface molecule changes.ResultsArctiin dose dependently decreased the production of NO and proinflammatory cytokines such as IL-1β, IL-6, TNF-α, and PGE2, and it reduced the gene and protein levels as determined by RT-PCR and western blot analysis, respectively. The expression of co-stimulatory molecules such as B7-1 and B7-2 were also inhibited by arctiin. Furthermore, the activation of the nuclear transcription factor, NF-κB in macrophages was inhibited by arctiin.ConclusionTaken together these results provide evidence of the bioactivity of arctiin in inflammatory diseases and suggest that arctiin may exert anti-inflammatory effect by inhibiting the pro-inflammatory mediators through the inactivation of NF-kB.

The effect of linarin on LPS-induced cytokine production and nitric oxide inhibition in murine macrophages cell line RAW264.7.

The herb,Chrysanthemum zawadskii var,latilobum commomly known as Gu-Jul-Cho in Korea, used in traditional medicine to treat pneumonia, bronchitis, cough, common cold, pharyngitis, bladder-related disorders, gastroenteric disorders, and hypertension. Linarin is the main active compound and the biological mechanisms of its activity are unclear. It is believed that effects of this herb may be exerted through the pluripotent effectors of linarin due to its ability to treat a variety of afflictions. In this study, the effects of linarin on the mouse macrophages cell line, RAW 264.7, were investigated. It was found that linarin could activate macrophages by producing cytokines. Monocytes and tissue macrophages produce at least two groups of protein mediators of inflammation, interleukin 1 (IL-1) and the tumor necrosis factor (TNF). Recent studies have shown that TNF and IL-1 modulate the inflammatory function of endothelial cells, leukocytes, and fibroblasts. TNF-α production by macrophages treated with linarin occured in a dose dependent manner. However, IL-1 production was largely unaffected by this natural product. This study demonstrated the ability of linarin to activate macrophages both directly and indirectly. Linarin also affect both cytokine production and nitric oxide inhibition, in addition to the expression of some surface molecules. Nitric oxide (NO), derived from L-argin-ine, is produced by two forms(constitutive and inducible) of nitric oxide synthase (NOS). The NO produced in large amounts by inducible NOS is known to be responsible for the vasodilation and hypotension observed in septic shock. Linarin was found to inhibit NO production in the LPS-activated RAW 264.7 cells. Linarin may be a useful candidate as a new drug for treating endotoxemia and the inflammation accompanied by NO overproduction. The linarin-treated total lymphocytes exhibited cytotoxicity in a dose dependent manner between 20 ng/ml and 40 (üg/ml. These results suggest that linarin may function through macrophage activation.

Activation of murine macrophage cell line RAW 264.7 by Korean propolis.

Monocytes and macrophages play a major role in defense mechanism of the host response to tumor, in part through the secretion of several potent products and macrophage cytokines. Monocytes and tissue macrophages produce at least two groups of protein mediators of inflammation, interleukin 1 (IL-1) and tumor necrosis factor (TIMF). Recent studies emphasizes that TNF and IL-1 modulate the inflammatory function of endothelial cells, leukocytes, and fibroblasts. In this study, our work is directed toward studying thein vitro effects of Korean propolis on the ability to induce cellular and secretory responses in murine macrophage cell line, RAW 264.7. It was found that Water Extract of Korean Propolis (WEP) could activate macrophages by producing cytokines. The production of the macrophage cytokines, IL-1 and TNF-α, by RAW 264.7 treated with WEP was examined from 2.5 μg/ml up to 25 μg/ml with dose dependent manner. Nitric oxide (NO) production was also increased when cells were exposed to combination of LPS and WEP from 2.5 μg/ml up to 25 μg/ml. At high dose of WEP (50 to 100 μg/ml) used to prescribe for anti-inflammatory and analgesic medicine showed inhibition of NO production in LPS-stimulated macrophage. Besides cytokine production, NO release, surface molecule expression and cell morphologic antigen expression were increased in response to the stimulation by WEP. These results suggested WEP may function through macrophage activation.

Immunomodulatory Effects of Dioscoreae Rhizome Against Inflammation through Suppressed Production of Cytokines Via Inhibition of the NF-κB Pathway

Dioscoreae Rhizome (DR) has been used in traditional medicine to treat numerous diseases and is reported to have anti-diabetes and anti-tumor activities. To identify a bioactive traditional medicine with anti-inflammatory activity of a water extract of DR (EDR), we determined the mRNA and protein levels of proinflammatory cytokines in macrophages through RT-PCR and western blot analysis and performed a FACS analysis for measuring surface molecules. EDR dose-dependently decreased the production of NO and pro-inflammatory cytokines such as IL-1β, IL-6, TNF-α, and PGE2, as well as mRNA levels of iNOS, COX-2, and pro-inflammatory cytokines, as determined by western blot and RT-PCR analysis, respectively. The expression of co-stimulatory molecules such as B7-1 and B7-2 was also reduced by EDR. Furthermore, activation of the nuclear transcription factor, NF-κB, but not that of IL-4 and IL-10, in macrophages was inhibited by EDR. These results show that EDR decreased pro-inflammatory cytokines via inhibition of NF-κB-dependent inflammatory protein level, suggesting that EDR could be a useful immunomodulatory agent for treating immunological diseases.

Cordyceps militaris Enhances MHC-restricted Antigen Presentation via the Induced Expression of MHC Molecules and Production of Cytokines.

Background Cordyceps militarys water extract (CME) has been reported to exert antitumor and immunomodulatory activities in vivo and in vitro. However, the therapeutic mechanism has not yet been elucidated. In this study, we examined the effects of CME on the antigen presenting function of antigen presenting cells (APCs). Methods Dendritic cells (DCs) were cultured in the presence of CME, and then allowed to phagocytose microspheres containing ovalbumin (OVA). After washing and fixing the efficacy of OVA, peptide presentation by DCs were evaluated using CD8 and CD4 T cells. Also, we confirmed the protein levels of proinflammatory cytokines through western blot analysis. Results CME enhanced both MHC class I and class II-restricted presentation of OVA in DCs. In addition, the expression of both MHC class I and II molecules was enhanced, but there was no changes in the phagocytic activity of exogenous OVA. Furthermore, CME induced the protein levels of iNOS, COX-2, proinflammatory cytokines, and nuclear p65 in a concentration-dependent manner, as determined by western blot. Conclusion These results provide an understanding of the mechanism of the immuno-enhancing activity of CME on the induction of MHC-restricted antigen presentation in relation to their actions on APCs.

Role of Salvia miltiorrhiza for Modulation of Th2-derived Cytokines in the Resolution of Inflammation

Background Salvia miltiorrhiza (SM) has been used to treat inflammatory diseases including edema and arthritis; however, the anti-inflammatory mechanism of SM action remains unresolved. Methods The effects of an ethanol extract of SM (ESM) on pro-inflammatory cytokines such as TNF-α, IL-1β, IL-6, and NO, on anti-inflammatory cytokines including IL-4, IL-10, TGF-β, and IL-1Ra have been studied in an attempt to elucidate the anti-inflammatory mechanism in murine macrophages. Results ESM inhibited the production of pro-inflammatory cytokines via down-regulation of gene and protein expression whereas it increased the anti-inflammatory cytokines. Furthermore, ESM inhibited the expression of the chemokines, RANTES and CX3CL1, as well as of inflammatory mediators such as TLR-4 and 11β-HSD1. Conclusion These results indicated that the regulatory effects of ESM may be mediated though the suppression of pro-inflammatory cytokines as well as the induction of anti-inflammatory cytokines. Consequently, we speculate that ESM has therapeutic potential for inflammation-associated disorders.

Auranofin, an immunosuppressive drug, inhibits MHC class I and MHC class II pathways of antigen presentation in dendritic cells

Auranofin (AF), an orally administered, gold-based, anti-arthritic agent, has emerged as a clinically useful therapeutic drug for the treatment of rheumatoid arthritis. In the present study, we examined the effects of AF on major histocompatibility complex (MHC)-restricted antigen presentation in dendritic cells (DCs), which are the most important accessory cells for the induction of T cell responses. A mouse dendritic cell line, DC2.4 cells, and DCs that were generated from mouse bone marrow cells by culturing with granulocyte macrophage-colony stimulating factor (GM-CSF) and interleukin (IL)-4 were each pretreated with AF for 2 hr, and then incubated with ovalbumin (OVA). After the 2-hr incubation, the DCs were fixed, and the amounts of OVA peptide-H-2Kb complexes were assessed using OVa-specific CD8+ T cells. AF inhibited MHC class I-restricted presentation of exogenous OVA. This inhibitory activity of AF appeared to be due not only to the inhibition of the phagocytic activity of DCs, but also to the suppression of MHC molecule expression on DCs. AF also inhibited MHC class II-restricted presentation of exogenous OVA. These results show that AF exerts immunosuppressive activity at least in part by inhibiting MHC-restricted antigen presentation in professional antigen-presenting cells.

Effects of mizoribine on MHC-restricted exogenous antigen presentation in dendritic cells

Mizoribine (MZR) has been shown to possess immunosuppressive activity that selectively inhibits the proliferation of lymphocytes by interfering with inosine monophosphate dehydrogenase. The efficacy of MZR is not only in patients who have had renal transplantation, but also in patients with rheumatoid arthritis (RA), lupus nephritis, and primary nephritic syndrome. Because the exact mechanism of its immunosuppressive action is not clear, the object of this study was to examine the ability of MZR to regulate the antigen presenting cells (APCs), dendritic cells (DCs). In this work, we tested whether MZR (1∼10 μg/mL) could inhibit the crosspresentation of DCs. DC2.4 cells (H-2Kb) or bone marrow-derived DCs (BM-DCs) generated from BM cells of C57BL/6 mouse (H-2Kb) were cultured in the presence of MZR with OVA-microspheres, and the amount of OVA peptide-class I MHC complexes was measured by a T cell hybridoma, B3Z, that recognizes OVA (257–264: SIINFEKL)-H-2Kb complex and expresses-galactosidase. MZR profoundly inhibited the expression of SIINFEKL-H-2Kb complexes. This inhibitory activity of MZR appeared to affect the phagocytic activity of DCs. MZR also decreased IL-2 production when we examined the effects of MZR on CD4+ T cells. These results provide an understanding of the mechanism of immunosuppressive activity of MZR on the inhibition of MHC-restricted antigen presentation and phagocytic activity in relation to their actions on APCs.