Hydroquinone Exhibits In Vitro and In Vivo Anti-Cancer Activity in Cancer Cells and Mice.

Hydroquinone (HQ, 1,4-benzenediol) is a hydroxylated benzene metabolite with various biological activities, including anti-oxidative, neuroprotective, immunomodulatory, and anti-inflammatory functions. However, the anti-cancer activity of HQ is not well understood. In this study, the in vitro and in vivo anti-cancer activity of HQ was investigated in various cancer cells and tumor-bearing mouse models. HQ significantly induced the death of A431, SYF, B16F10, and MDA-MB-231 cells and also showed a synergistic effect on A431 cell death with other anti-cancer agents, such as adenosine-2',3'-dialdehyde and buthionine sulfoximine. In addition, HQ suppressed angiogenesis in fertilized chicken embryos. Moreover, HQ prevented lung metastasis of melanoma cells in mice in a dose-dependent manner without toxicity and adverse effects. HQ (10 mg/kg) also suppressed the generation of colon and reduced the thickness of colon tissues in azoxymethane/dextran sodium sulfate-injected mice. This study strongly suggests that HQ possesses in vitro and in vivo anti-cancer activity and provides evidence that HQ could be developed as an effective and safe anti-cancer drug.

p53-derived host restriction of HIV-1 replication by protein kinase R-mediated Tat phosphorylation and inactivation.

UNLABELLED: Tumor suppressor p53 has been suggested to be a host restriction factor against HIV-1 replication, but the detailed molecular mechanism has remained elusive for decades. Here, we demonstrate that p53-mediated HIV-1 suppression is attributed to double-stranded RNA (dsRNA)-dependent protein kinase (PKR)-mediated HIV-1 trans-activator (Tat) phosphorylation and inactivation. p53 silencing significantly enhanced HIV-1 replication in infected cells. Ectopic expression of p53 suppressed Tat activity, which was rescued by PKR silencing. In addition, ectopic expression of PKR abolished Tat activity in p53(-/-) and eIF2α(CA) cells. Finally, we found that HIV-1 infection activates p53, followed by the induction and activation of PKR. PKR directly interacted with HIV-1 Tat and phosphorylates the first exon of Tat exclusively at five Ser/Thr residues (T23, T40, S46, S62, and S68), which inhibits Tat-mediated provirus transcription in three critical steps: (i) phosphorylation near the arginine-rich motif (ARM) inhibits Tat translocation into the nucleus, (ii) accumulation of Tat phosphorylation abolishes Tat-Tat-responsive region (TAR) binding, and (iii) Tat phosphorylation at T23 and/or T40 obliterates the Tat-cyclin T1 interaction. These five Ser/Thr sites on Tat were highly conserved in HIV-1 strains prevalent in Europe and the United States. Taken together, our findings indicate that p53-derived host restriction of HIV-1 replication is likely attributable, at least in part, to a noncanonical p53/PKR/Tat phosphorylation and inactivation pathway in HIV-1 infection and AIDS pathogenesis. IMPORTANCE: HIV-1-mediated disease progression to AIDS lasts for years to decades after primary infection. Host restriction and associated viral latency have been studied for several decades. p53 has been suggested as an important host restriction factor against HIV-1 replication. However, the detailed molecular mechanism is still unclear. In the present study, we found that the p53-mediated HIV-1 restriction is attributed to a p53/PKR/Tat-inactivation pathway. HIV-1 infection activated p53, which subsequently induced PKR expression and activation. PKR directly phosphorylated Tat exclusively at five specific Ser/Thr residues, which was accompanied by significant suppression of HIV-1 replication. Accumulation of Tat phosphorylation at these sites inhibited Tat function by blocking Tat nuclear localization, Tat binding to TAR, and Tat-cyclin T1 interaction. Our findings provide a better understanding of the p53-derived host restriction mechanism against HIV-1 replication in AIDS pathogenesis and may contribute to further research focusing on the investigation of potential therapeutic targets for HIV-1.

Egr2 induced during DC development acts as an intrinsic negative regulator of DC immunogenicity.

Early growth response gene 2 (Egr2), which encodes a zinc finger transcription factor, is rapidly and transiently induced in various cell types independently of de novo protein synthesis. Although a role for Egr2 is well established in T-cell development, Egr2 expression and its biological function in dendritic cells (DCs) have not yet been described. Here, we demonstrate Egr2 expression during DC development, and its role in DC-mediated immune responses. Egr2 is expressed in the later stage of DC development from BM precursor cells. Even at steady state, Egr2 is highly expressed in mouse splenic DCs. Egr2-knockdown (Egr2-KD) DCs showed increased levels of major histocompatability complex (MHC) class I and II and co-stimulatory molecules, and enhanced antigen uptake and migratory capacities. Furthermore, Egr2-KD abolished SOCS1 expression and signal transducer and activator of transcription 5 (STAT5) activation during DC development, probably resulting in the enhancement of IL-12 expression and Th1 immunogenicity of a DC vaccine. DC-mediated cytotoxic T lymphocyte (CTL) activation and antitumor immunity were significantly enhanced by Egr2-KD, and impaired by Egr2 overexpression in antigen-pulsed DC vaccines. These data suggest that Egr2 acts as an intrinsic negative regulator of DC immunogenicity and can be an attractive molecular target for DC vaccine development.

8-(Tosylamino)quinoline inhibits macrophage-mediated inflammation by suppressing NF-κB signaling.

AIM: The macrophage-mediated inflammatory response may contribute to the development of cancer, diabetes, atherosclerosis and septic shock. This study was to characterize several new compounds to suppress macrophage-mediated inflammation. METHODS: Peritoneal macrophages from C57BL/6 male mice and RAW264.7 cells were examined. Anti-inflammatory activity was evaluated in the cells exposed to lipopolysaccharide (LPS). The mechanisms of the anti-inflammatory activity were investigated via measuring transcription factor activation in response to specific signals and via assaying the activities of the target kinases. RESULTS: Of 7 candidate compounds tested, 8-(tosylamino)quinoline (8-TQ, compound 7) exhibited the strongest activities in suppressing the production of NO, TNF-α, and PGE(2) in LPS-activated RAW264.7 cells and peritoneal macrophages (the IC(50) values=1-5 µmol/L). This compound (1.25-20 µmol/L) dose-dependently suppressed the expression of the pro-inflammatory genes for iNOS, COX-2, TNF-α, and the cytokines IL-1ß and IL-6 at the level of transcription in LPS-activated RAW264.7 cells. 8-TQ (20 µmol/L) significantly suppressed the activation of NF-κB and its upstream signaling elements, including inhibitor of κB (IκBα), IκBα kinase (IKK) and Akt in LPS-activated RAW264.7 cells. In in vivo experiments, oral administration of 20 and 40 mg/kg 8-TQ for 3 d significantly alleviated the signs of LPS-induced hepatitis and HCl/EtOH-induced gastritis, respectively, in ICR mice. CONCLUSION: 8-TQ (compound 7) exerts significant anti-inflammatory activity through the inhibition of the Akt/NF-κB pathway, thus may be developed as a novel anti-inflammatory drug.

The role of Src kinase in macrophage-mediated inflammatory responses.

Src kinase (Src) is a tyrosine protein kinase that regulates cellular metabolism, survival, and proliferation. Many studies have shown that Src plays multiple roles in macrophage-mediated innate immunity, such as phagocytosis, the production of inflammatory cytokines/mediators, and the induction of cellular migration, which strongly implies that Src plays a pivotal role in the functional activation of macrophages. Macrophages are involved in a variety of immune responses and in inflammatory diseases including rheumatoid arthritis, atherosclerosis, diabetes, obesity, cancer, and osteoporosis. Previous studies have suggested roles for Src in macrophage-mediated inflammatory responses; however, recently, new functions for Src have been reported, implying that Src functions in macrophage-mediated inflammatory responses that have not been described. In this paper, we discuss recent studies regarding a number of these newly defined functions of Src in macrophage-mediated inflammatory responses. Moreover, we discuss the feasibility of Src as a target for the development of new pharmaceutical drugs to treat macrophage-mediated inflammatory diseases. We provide insights into recent reports regarding new functions for Src that are related to macrophage-related inflammatory responses and the development of novel Src inhibitors with strong immunosuppressive and anti-inflammatory properties, which could be applied to various macrophage-mediated inflammatory diseases.

Nanostructured, self-assembling peptide K5 blocks TNF-α and PGE2 production by suppression of the AP-1/p38 pathway.

Nanostructured, self-assembling peptides hold promise for a variety of regenerative medical applications such as 3D cell culture systems, accelerated wound healing, and nerve repair. The aim of this study was to determine whether the self-assembling peptide K5 can be applied as a carrier of anti-inflammatory drugs. First, we examined whether the K5 self-assembling peptide itself can modulate various cellular inflammatory responses. We found that peptide K5 significantly suppressed the release of tumor-necrosis-factor- (TNF-) α and prostaglandin E2 (PGE2) from RAW264.7 cells and peritoneal macrophages stimulated by lipopolysaccharide (LPS). Similarly, there was inhibition of cyclooxygenase- (COX-) 2 mRNA expression assessed by real-time PCR, indicating that the inhibition is at the transcriptional level. In agreement with this finding, peptide K5 suppressed the translocation of the transcription factors activator protein (AP-1) and c-Jun and inhibited upstream inflammatory effectors including mitogen activated protein kinase (MAPK), p38, and mitogen-activated protein kinase kinase 3/6 (MKK 3/6). Whether this peptide exerts its effects via a transmembrane or cytoplasmic receptor is not clear. However, our data strongly suggest that the nanostructured, self-assembling peptide K5 may possess significant anti-inflammatory activity via suppression of the p38/AP-1 pathway.

Molecular mechanism of macrophage activation by red ginseng acidic polysaccharide from Korean red ginseng.

Red ginseng acidic polysaccharide (RGAP), isolated from Korean red ginseng, displays immunostimulatory and antitumor activities. Even though numerous studies have been reported, the mechanism as to how RGAP is able to stimulate the immune response is not clear. In this study, we aimed to explore the mechanism of molecular activation of RGAP in macrophages. RGAP treatment strongly induced NO production in RAW264.7 cells without altering morphological changes, although the activity was not strong compared to LPS-induced dendritic-like morphology in RAW264.7 cells. RGAP-induced NO production was accompanied with enhanced mRNA levels of iNOS and increases in nuclear transcription factors such as NF-κB, AP-1, STAT-1, ATF-2, and CREB. According to pharmacological evaluation with specific enzyme inhibitors, Western blot analysis of intracellular signaling proteins and inhibitory pattern using blocking antibodies, ERK, and JNK were found to be the most important signaling enzymes compared to LPS signaling cascade. Further, TLR2 seems to be a target surface receptor of RGAP. Lastly, macrophages isolated from RGS2 knockout mice or wortmannin exposure strongly upregulated RGAP-treated NO production. Therefore, our results suggest that RGAP can activate macrophage function through activation of transcription factors such as NF-κB and AP-1 and their upstream signaling enzymes such as ERK and JNK.

Cyclic adenosine monophosphate (cAMP)-induced histone hyperacetylation contributes to its antiproliferative and differentiation-inducing activities.

Histone acetylation is linked to the control of chromatin remodeling, which is involved in cell growth, proliferation, and differentiation. It is not fully understood whether cyclic adenosine monophosphate (cAMP), a representative differentiation-inducing molecule, is able to modulate histone acetylation as part of its anticancer activity. In the present study, we aimed to address this issue using cell-permeable cAMP, i.e. dibutyryl cAMP (dbcAMP) and C6 glioma cells. As reported previously, under the conditions of our studies, treatment with dbcAMP clearly arrested C6 cell proliferation and altered their morphology. Its antiproliferative and differentiation-inducing activity in C6 glioma cells involved upregulation of p219WAF/CIP), p27(kip1), glial fibrillary acidic protein (GFAP), and Cx43, as well as downregulation of vimentin. Furthermore, dbcAMP modulated the phosphorylation of ERK and Akt in a time-dependent manner and altered the colocalization pattern of phospho-Src and the actin cytoskeleton. Interestingly, dbcAMP upregulated the enzyme activity of histone acetyltransferase (HAT) and, in parallel, enhanced cellular acetyllysine levels. Finally, the hyperacetylation-inducing compound, sodium butyrate (NaB), a histone deacetylase (HDAC) inhibitor, displayed similar anticancer activity to dbcAMP. Therefore, our data suggest that antiproliferative and differentiation-inducing activities of dbcAMP may be generated by its enhanced hyperacetylation function.

Knock-down of protein L-isoaspartyl O-methyltransferase increases ß-amyloid production by decreasing ADAM10 and ADAM17 levels.

AIM: To examine the role of protein L-isoaspartyl O-methyltransferase (PIMT; EC 2.1.1.77) on the secretion of Aß peptides. METHODS: HEK293 APPsw cells were treated with PIMT siRNA or adenosine dialdehyde (AdOX), a broad-spectrum methyltransferase inhibitor. Under the conditions, the level of Aß secretion and regulatory mechanism by PIMT were examined. RESULTS: Knock-down of PIMT and treatment with AdOX significantly increased Aß(40) secretion. Reductions in levels of PIMT decreased the secretion of soluble amyloid precursor protein alpha (sAPPα) without altering the total expression of APP or its membrane-bound C83 fragment. However, the levels of the C99 fragment generated by ß-secretase were enhanced. Moreover, the decreased secretion of sAPPα resulting from PIMT knock-down seemed to be linked with the suppression of the expression of α-secretase gene products, α-disintegrin and metalloprotease 10 (ADAM10) and ADAM17, as indicated by Western blot analysis. In contrast, ADAM10 was not down-regulated in response to treatment with the protein arginine methyltransferase (PRMT) inhibitor, AMI-1. CONCLUSION: This study demonstrates a novel role for PIMT, but not PRMT, as a negative regulator of Aß peptide formation and a potential protective factor in the pathogenesis of AD.

p38-targeted inhibition of interleukin-12 expression by ethanol extract from Cordyceps bassiana in lipopolysaccharide-activated macrophages.

Cordyceps species have been known as ethnopharmacologically valuable mushroom in Korea, China, and Japan. This plant has been reported to exhibit a variety of pharmacological activities such as antioxidative, anticancer, anti-inflammatory, antidiabetic, and antiobesity effects. Although numerous pharmacological potentials of Cordyceps spp. have been demonstrated, immunomodulatory effect of Cordyceps bassiana has not been published yet. To evaluate its immunomodulatory activity, macrophages activated by lipopolysaccharide (LPS) were employed and the production of interleukin-12 (IL-12) was explored in terms of understanding its molecular inhibitory mechanism. Seventy percent of ethanol extract from Cordyceps bassiana (Cb-EE) was able to suppress the expression of IL-12, a cytokine regulating interferon-γ (IFN-γ)-producing T helper type 1 (Th1) polarization response, at the transcriptional levels. The inhibitory effect of Cb-EE seemed to be due to activator protein-1 (AP-1) translocation inhibition, according to immunoblotting analysis with nuclear fraction and luciferase assay. In agreement with this, Cb-EE strongly suppressed the phosphorylation of p38, a prime signal to stimulate AP-1 translocation and IL-12 production, strongly suppressed by SB203580, a p38 inhibitor. Furthermore, this extract also suppressed IFN-γ production in both phytohemaglutinin A and LPS-activated splenocytes. Our results suggest that Cb-EE can be applied as a Th1 response regulatory herbal medicine.

The TRIF/TBK1/IRF-3 activation pathway is the primary inhibitory target of resveratrol, contributing to its broad-spectrum anti-inflammatory effects.

Resveratrol, a stilbene type compound identified in wine and fruit juice, has been found to exhibit various pharmacological activities such as anti-oxidative, anti-cancerous, anti-inflammatory and anti-aging effects. Although numerous papers have explored the pharmacology of resveratrol in one particular cellular action, how this compound can have multiple effects simultaneously has not been fully addressed. In this study, therefore, we explored its broad-spectrum inhibitory mechanism using lipopolysaccharide (LPS)-mediated inflammatory responses and reporter gene assays involving overexpression of toll like receptor (TLR) adaptor molecules. Co-transfection of adaptor molecules such as (1) myeloid differentiation primary response gene 88 (MyD88), (2) Toll/4ll-1 Receptor-domain-containing adapter-inducing interferon-beta (TRIF), (3) TRIF-related adaptor molecule (TRAM), or (4) TANK-binding kinase (TBK) 1 strongly enhanced luciferase activity mediated by transcription factors including nuclear factor (NF)-KB, activator protein (AP)-1, and interferon regulatory factor (IRF)-3. Of the adaptor proteins, TRIF and TBK1 but not MyD88 and IKK enhanced luciferase activity mediated by these transcription factors. Resveratrol dose-dependently suppressed LPS-induced NO production in macrophages. It also blocked the increases in levels of mRNA for IFN-1, tumor necrosis factor (TNF)-alpha, and inducible nitric oxide synthase (iNOS) that were induced by LPS. Resveratrol diminished the translocation or activation of IRF-3 at 90min, c-Jun, a subunit of AP-1, and STAT-1 at 120 min, and p50, a subunit of NF-KB, at 60 and 90 min. Resveratrol strongly suppressed the up-regulation of luciferase activity induced by these adaptor molecules with IC50 values of 5 to 65 microM. In particular, higher inhibitory effects of resveratrol were when TRIF or TBK1 were overexpressed following cotransfection of luciferase constructs with IRF-3 binding sequences. Taken together, our data suggest that the suppression of TRIF and TBK1, which mediates transcriptional activation of NF-kappaB, AP-1, and IRF-3, contributes to resveratrol's broad-spectrum inhibitory activity, and that this compound can be further developed as a lead anti-inflammatory compound.

Inhibition of cytokine expression by a butanol extract from Cordyceps bassiana.

Cordyceps species have been known since long as a multi-utility ethnomedicinal herbal in Korea, China and Japan. It has been reported to exhibit a number of properties such as anti-oxidative, anti-cancer, antiinflammatory, anti-diabetic, and anti-obesity effects. In a previously conducted study, we had demonstrated that the ethanol extract of Cordyceps bassiana was able to suppress the production of interleukin (IL)-12 and interferon (IFN)-gamma in macrophages and T lymphocytes. In this study, we were able to further explore the molecular basis of its inhibitory mechanism using a butanol fraction of this herbal (Cb-BF) preparation. Similarly, this fraction also blocked the expression of cytokines such as IL-12 and tumor necrosis factor (TNF)-alpha as well as the proliferation of splenic lymphocytes and their production of IFN-gamma but not IL-4. Cb-BF suppressed the luciferase activities that are mediated by nuclear factor (NF)-kappaB, activator protein (AP)-1, and signal transducers and activators of transcription (STAT)-1. In agreement with this, these fractions diminished the translocation of the transcription factors into the nucleus. The study also demonstrated that the upstream signaling events for the activation of these factors such as spleen tyrosine kinase (Syk), janus kinase (JAK)-2, and extracellular signal-regulated kinase (ERK) were suppressed. Therefore, these results suggest that the butanol extract of Cordyceps bassiana may contain more than one active component capable of inhibiting the inflammatory signaling cascade and this can be considered as a potential candidate for treatment of diseases that require suppression of immune system.

Protective effect of stress-induced liver damage by saponin fraction from Codonopsis lanceolata.

Saponins are valuable principles found in various herbal medicine with pharmaceutical, cosmetical and nutraceutical merits. In this study, we evaluated the protective role of saponin fraction (Cl-SF), prepared from Codonopsis lanceolata, an ethnopharmacologically famous plant in Korea, China and Japan, on water immersion stress-induced liver damage and radical generation. Cl-SF clearly decreased the up-regulated levels of serum glutamate-oxalacetate transaminase and glutamate-pyruvate-transaminase induced by water-immersed stress conditions. Furthermore, Cl-SF seemed to block the stress-induced radicals. Thus, Griess and DPPH assays revealed that Cl-SF significantly suppressed both radical generation in sodium nitroprusside-treated RAW264.7 cells and nitric oxide production in LPS-treated RAW264.7 cells. Therefore, these results suggest that Cl-SF may be considered as a promising stress-regulatory principle with radical scavenging actions.

Functional activation of macrophages, monocytes and splenic lymphocytes by polysaccharide fraction from Tricholoma matsutake.

Mushroom-derived polysaccharides (beta-glucans) are considered as a valuable biopharmaceutical principle without displaying side effects. Although Tricholoma matsutake is well-known mushroom in Korea, Japan and China, the immunoregulatory roles of T. matsutake-derived polysaccharides were not fully elucidated yet. In this study, we continued to evaluate the immunomodulatory effect of T. matsutake-derived polysaccharide fraction (TmC-2) using functional activation models of macrophages, monocytes and splenic lymphocytes. TmC-2 treatment strongly increased the production of NO and TNF-alpha. Phagocytic uptake and ROS generation was also up-regulated by TmC-2. Interestingly, TmC-2 stimulated CD29-mediated cell-cell or cell-finbronectin adhesions in monocytes, while CD43-mediated cell adhesion was down-regulated. Interestingly, the enhancement of proliferation and IFN-gamma production was striking observed in TmC-2-treated splenic lymphocytes. The activation seemed to be mediated by up-regulating intracellular signaling cascades such as PI3K/Akt and MAPK (ERK and p38) and by the involvement of surface receptors (dectin-1 and TLR-2). Therefore, our results suggest that this TmC-2 from T. matsutake can be developed as a promising immunostimulatory principle, applicable to people with lowered immunomodulatory potentials.

Inhibitory effect of saponin fraction from Codonopsis lanceolata on immune cell-mediated inflammatory responses.

Saponin components are known to be pharmaceutically, cosmetically and nutraceutically valuable principles found in various herbal medicine. In this study, we evaluated the inhibitory role of saponin fraction (SF), prepared from C. lanceolata, an ethnopharmacologically famous plant, on various inflammatory responses managed by monocytes, macrophages, lymphocytes and mast cells. SF clearly suppressed the release of nitric oxide (NO) and tumor necrosis factor (TNF)-alpha, but not prostaglandin E(2) (PGE(2)). While this fraction did not scavenge the reactivity of SNP-induced radicals in RAW264. 7 cells, it negatively modulated the phagocytic uptake of macrophages treated with FITC-dextran. Interestingly, SF completely diminished cell-cell adhesion events induced by both CD29 and CD43, but not cell-fibronectin adhesion. Concanavalin (Con) A [as well phytohemaglutinin A (PHA)]-induced proliferation of splenic lymphocytes as well as interferon (IFN)-gamma production were also clearly suppressed by SF treatment. Finally, SF also significantly blocked the degranulation process of mast cell line RBL-2H3 cell as assessed by DNP-BSA-induced beta-hexosaminidase activity. The anti-inflammatory activities of SF on NO production seemed to be due to inhibition of nuclear factor (NF)-kappaB activation signaling, since it blocked the phosphorylation of inhibitor of kappaB (IkappaB)alpha as well as inducible NO synthase (iNOS) expression. Therefore, these results suggest that SF may be considered as a promising herbal medicine with potent anti-inflammatory actions.

In vitro and in vivo anti-inflammatory effects of taheebo, a water extract from the inner bark of Tabebuia avellanedae.

AIM OF STUDY: Tabebuia spp. (Bignoniaceae) are native to tropical rain forests throughout Central and South America and have long been used as a folk medicine to treat bacterial infection, blood coagulation, cancer and inflammatory diseases. In this study, we aimed to demonstrate the ethnopharmacological activity of Tabebuia avellanedae in various in vitro and in vivo inflammatory conditions. MATERIALS AND METHODS: To do this, LPS-stimulated macrophages and arachidonic acid or croton oil-induced mouse ear edema models were employed. RESULTS: The water extract (taheebo) of Tabebuia avellanedae significantly suppressed the production of prostaglandin (PG) E(2) and nitric oxide (NO), and blocked the mRNA expression of their catalyzing enzymes (cyclooxygenase [COX)-II] and inducible NO synthase [iNOS], respectively), in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. The blockade of inflammatory mediators by taheebo seemed to be the result of the interruption of extracellular signal-related kinase (ERK) activation, according to immunoblotting analysis and the NO assay, where LPS strongly induced the phosphorylation (a hallmark of activation) of ERK, and U0126, a selective ERK inhibitor, was found to strongly inhibit PGE(2) production. Similarly, oral administration of taheebo (100mg/kg) for 1 week completely diminished mouse ear edema induced by arachidonic acid, an activator of COX-II, but not croton oil, an activator of lipoxygenase. CONCLUSIONS: These data suggest that the ethnopharmacological action of taheebo may be due to its negative modulation of macrophage-mediated inflammatory responses by suppressing PGE(2) production. Thus, this water extract may be developed as a new therapeutic remedy for various inflammatory diseases such as arthritis and atherosclerosis.

Immunostimulatory activities of polysaccharides from liquid culture of pine-mushroom Tricholoma matsutake.

Mushrooms are regarded as one of the well-known foods and biopharmaceutical materials with a great deal of interest. Polysaccharide beta-glucan is the major component of mushrooms that displays various biological activities such as antidiabetic, anticancer, and antihyperlipidemic effects. In this study, we compared the immunostimulatory potency of polysaccharide fractions, prepared from liquid culture of pinemushroom Tricholoma matsutake, with a potent immunogen lipopolysaccharide (LPS), and their molecular mechanisms on the functional activation of macrophages. We found that fraction II (TMF-II) was able to comparably upregulate or highly enhance the phenotypic functions of macrophages such NO production and cytokine (IL-1beta, IL-6, IL-12, and TNF-alpha) expression, to LPS. TMF-II triggered the phosphorylation of IkappaBalpha, a critical step for NF-kappaB activation and translocation. Of the upstream signaling enzymes tested, Src and Akt were thought to be the responsible upstream signaling components in induction of NO production, although TMF-II strongly upregulated the phosphorylation of all MAPK pathways. Therefore, our data suggest that T. matsutake-derived beta-glucan may exert its immunostimulating activities with similar potency to LPS via activation of multiple signaling pathways linked to NF-kappaB activation.

Surfactin blocks NO production in lipopolysaccharide-activated macrophages by inhibiting NF-kappaB activation.

Surfactin is a natural biosurfactant derived from Bacillus subtilis and has various biological activities such as anticancer, antiplatelet, and anti-inflammatory effects. In this study, the inhibitory mechanism of surfactin in NO production from macrophages was examined. Surfactin downregulated LPSinduced NO production in RAW264.7 cells and primary macrophages with IC50 values of 31.6 and 22.4 microM, respectively. Immunoblotting analysis showed that surfactin strongly blocked the phosphorylation of IKK and IkBa and the nuclear translocation of NF-kappaB (p65). Therefore, these data suggest that surfactin may act as a bacterium-derived antiinflammatory agent with anti-NF-kappaB activity.

Regulatory effects of Codonopsis lanceolata on macrophage-mediated immune responses.

Codonopsis lanceolata L. has long been used as a folk medicine in Korea, Japan and China for the treatment of lung inflammatory diseases. In this study, therefore, we aimed to demonstrate its ethnopharmacological activity by examining macrophage-function regulating effects. The total methanol extracts of fresh leaves (l-TME) or roots (r-TME) of Codonopsis lanceolata L. significantly suppressed the production of pro-inflammatory mediators (nitric oxide [NO] and tumor necrosis factor [TNF-alpha]) without altering mRNA levels. The expression of interleukin (IL)-3 and IL-6, however, was strongly diminished. According to the analysis of signaling enzyme activation by immunoblotting, phospho-IkappaB levels, a representative pro-inflammatory gene activation pathway, were not affected by the TMEs. By contrast, the Raf-ERK signaling pathway, which was involved in regulation of post-translational modification of pro-inflammatory gene products, was strongly blocked after 6-h of exposure. Moreover, l-TME down-regulated LPS-mediated phagocytic uptake and CD29-mediated cell-cell adhesion, while r-TME strongly up-regulated these two cellular events as well as fibronectin-cell adhesion. The surface levels of the costimulatory molecules (CD80 and CD86) of RAW264.7 cells were also enhanced by these extracts. l-TME also diminished functional activation (assessed by NO production) and the surface level of dectin-1, but not toll-like receptor (TLR)-2. Taken together, these data suggest that Codonopsis lanceolata may have the ability to modulate macrophage-mediated immune responses, thus contributing to its anti-inflammatory activity.