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.

3-(4-(tert-Octyl)phenoxy)propane-1,2-diol suppresses inflammatory responses via inhibition of multiple kinases.

Novel anti-inflammatory compounds were synthesised by derivatization of militarin, a compound isolated from Cordyceps militaris that is an ethnopharmacologically well-known herbal medicine with multiple benefits such as anti-cancer, anti-inflammatory, anti-obesity, and anti-diabetic properties. In this study, we explored the in vitro and in vivo anti-inflammatory potencies of these compounds during inflammatory responses, their inhibitory mechanisms, and acute toxicity profiles. To do this, we studied inflammatory conditions using in vitro lipopolysaccharide-treated macrophages and several in vivo inflammatory models such as dextran sodium sulphate (DSS)-induced colitis, EtOH/HCl-induced gastritis, and arachidonic acid-induced ear oedema. Methods used included real-time PCR, immunoblotting analysis, immunoprecipitation, reporter gene assays, and direct kinase assays. Of the tested compounds, compound III showed the highest nitric oxide (NO) inhibitory activity. This compound also inhibited the production of prostaglandin (PG)E(2) at the transcriptional level by suppression of Syk/NF-κB, IKKɛ/IRF-3, and p38/AP-1 pathways in lipopolysaccharide (LPS)-activated RAW264.7 cells and peritoneal macrophages. Consistent with these findings, compound III strongly ameliorated inflammatory symptoms in colitis, gastritis, and ear oedema models. In acute toxicity tests, there were no significant differences in body and organ weights, serum parameters, and stomach lesions between the untreated and compound III-treated mice. Therefore, this compound has the potential to be served as a lead chemical for developing a promising anti-inflammatory drug candidate with multiple kinase targets.

In vitro and in vivo anti-inflammatory activities of Polygonum hydropiper methanol extract.

ETHNOPHARMACOLOGICAL RELEVANCE: Polygonum hydropiper L. (Polygonaceae) has been traditionally used to treat various inflammatory diseases such as rheumatoid arthritis. However, no systematic studies on the anti-inflammatory actions of Polygonum hydropiper and its inhibitory mechanisms have been reported. This study is therefore aimed at exploring the anti-inflammatory effects of 99% methanol extracts (Ph-ME) of this plant. MATERIALS AND METHODS: The effects of Ph-ME on the production of inflammatory mediators in RAW264.7 cells and peritoneal macrophages were investigated. Molecular mechanisms underlying the effects, especially inhibitory effects, were elucidated by analyzing the activation of transcription factors and their upstream signalling, and by evaluating the kinase activities of target enzymes. Additionally, a dextran sulphate sodium (DSS)-induced colitis model was employed to see whether this extract can be used as an orally available drug. RESULTS: Ph-ME dose-dependently suppressed the release of nitric oxide (NO), tumour necrosis factor (TNF)-α, and prostaglandin (PG)E(2), in RAW264.7 cells and peritoneal macrophages stimulated by lipopolysaccharide (LPS). Ph-ME inhibited mRNA expression of pro-inflammatory genes such as inducible NO synthase (iNOS), cyclooxygenase (COX)-2, and TNF-α by suppressing the activation of nuclear factor (NF)-κB, activator protein (AP-1), and cAMP responsive element binding protein (CREB), and simultaneously inhibited its upstream inflammatory signalling cascades, including cascades involving Syk, Src, and IRAK1. Consistent with these findings, the extract strongly suppressed the kinase activities of Src and Syk. Based on HPLC analysis, quercetin, which inhibits NO and PGE(2) activities, was found as one of the active ingredients in Ph-ME. CONCLUSION: Ph-ME exerts strong anti-inflammatory activity by suppressing Src/Syk/NF-κB and IRAK/AP-1/CREB pathways, which contribute to its major ethno-pharmacological role as an anti-gastritis remedy.

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.

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.

Inhibition of 2,4-dinitrofluorobenzene-induced atopic dermatitis by topical application of the butanol extract of Cordyceps bassiana in NC/Nga mice.

ETHNOPHARMACOLOGICAL SIGNIFICANCE: The Cordyceps species are insect-borne mushrooms that have been ethnopharmacologically used for skin diseases such as eczema and dermatitis. AIM OF THE STUDY: In this study, we investigated the curative effects of the butanol fraction (CBBF) of Cordyceps bassiana on atopic dermatitis. MATERIALS AND METHODS: Dermatitis was induced by repeated application of 2,4-dinitrofluorobenzene (DNFB) in NC/Nga mice. After a topical application of CBBF on the skin lesions, the dermatitis score, epidermal thickness, mast cell number, and interleukin (IL)-4 and interferon (IFN)-γ, as well as the levels of histamine and immunoglobulin E (IgE) in the serum, were measured. Moreover, effect of CBBF on histamine release was examined using RBL-2H3 under stimulation with 2,4-dinitrophenylated bovine serum albumin (DNP-BSA). RESULTS: CBBF inhibited atopic dermatitis symptoms and signs in the DNFB-treated NC/Nga mice. The suppressive activity of topically applied CBBF may be due to the dose-dependent blockade of a series of immunopathological events, including the release of histamine, the production of IgE, and the secretion of IL-4 and IFN-γ. However, this extract did not directly suppress the degranulation process, assessed by measuring ß-hexosaminidase release. CONCLUSIONS: Our results suggest that CBBF can be applied as an effective herbal remedy to treat atopic dermatitis.

In vitro and in vivo anti-inflammatory effects of ethanol extract from Acer tegmentosum.

AIM OF STUDY: Acer tegmentosum has been traditionally used for folk medicine to treat hepatic disorders such as hepatitis, hepatic cancer, and hepatic cirrhosis. In this study, we demonstrate the ethno-pharmacological activity of Acer tegmentosum in in vitro and in vivo inflammatory conditions. RESULTS: The 70% ethanol extract (At-EE) of Acer tegmentosum dose-dependently diminished the production of nitric oxide (NO), tumour necrosis factor (TNF)-alpha, and prostaglandin (PG)E(2), in lipopolysaccharide (LPS)-activated RAW264.7 cells and peritoneal macrophages, by a transcriptional mechanism. At-EE also suppressed the activation of nuclear factor (NF)-kappaB, activator protein (AP)-1, and cAMP-responsive element binding (CREB), and simultaneously blocked their upstream inflammatory signalling cascades, including Akt, p38, and JNK. Furthermore, At-EE protected against LPS-induced cell death induced by reactive oxygen species (ROS) and reactive nitrogen species (RNS) and neutralized reactive species generation. In agreement with the in vitro results, orally administered At-EE strongly ameliorated ear oedema formation induced by arachidonic acid. CONCLUSION: At-EE displays strong anti-inflammatory activities in vitro and in vivo, contributing to its major ethno-pharmacological role such as anti-hepatitis remedy and may be applicable to novel anti-inflammatory therapeutics.

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.

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.

Regulatory effects of Codonopsis lanceolata on gene expression of GM-CSF in macrophage-like cells.

AIM OF THE STUDY: We aimed to demonstrate ethnopharmacological role of Codonopsis lanceolata L., known to be used as a folk qi tonic herb to aid those who are weakened by blood loss or other injury in Korea, by examining the expressional level of hematopoietic cytokines. RESULTS: BuOH fraction strongly up-regulated mRNA expression of granulocyte-macrophage-colony stimulating factor (GM-CSF). Similarly, BuOH fraction also increased the proliferation of splenocytes. According to the analysis of transcription factors and their regulatory signaling enzymes by using reporter gene assay, pharmacological dissection and Western blotting, NF-kappaB and AP-1 were found to be up-regulated by BuOH fraction. Furthermore, ERK and PI3K seemed to be regarded as positive upstream signaling enzymes responsible for activation of these transcription factors. CONCLUSION: These data suggest that the enthopharmacological role of Codonopsis lanceolata on the recovery of blood loss and spleen qi may be due to its up-regulatory effect of GM-CSF expression via activating relevant signaling cascades.

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.

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.

Hinokitiol, a natural tropolone derivative, inhibits TNF-alpha production in LPS-activated macrophages via suppression of NF-kappaB.

In this study, we examined the modulatory effect of hinokitiol (HK) on the production of tumor necrosis factor (TNF)-alpha, a critical factor involved in skin inflammation and hair follicle apoptosis. HK effectively suppressed TNF-alpha production in lipopolysaccharide (LPS)-activated, macrophage-like (RAW264.7) cells. This compound also diminished mRNA synthesis of TNF-alpha, indicating that HK-mediated inhibition may occur at the transcriptional level. Moreover, this compound down-regulated the phosphorylation of PDK1, Akt/PKB, and ERK, resulting in a loss of nuclear factor (NF)-kappaB activation, which is detectable by immunoblotting and reporter gene assays. Therefore, these results suggest that HK may cure hair loss by suppressing factors that promote follicular apoptosis, such as TNF-alpha, in addition to stimulating new hair growth.

In vitro immunoregulatory effects of Korean mistletoe lectin on functional activation of monocytic and macrophage-like cells.

Korean mistletoe lectin (KML) is one of the major active components in Viscum album var. (coloratum), displaying various biological effects such as anti-tumor and anti-metastatic activities. Even though it has been shown to boost host immune defense mechanisms, the immunomodulatory effects of KML on specific immune responses mediated by macrophages have not been fully elucidated. Therefore, in this study, we aimed to demonstrate KML's regulatory roles on macrophage-mediated immune responses. KML clearly blocked lipopolysaccharide (LPS)-induced events [expression of interleukin (IL)-10, nitric oxide (NO) production and phagocytic uptake], and suppressed the normal expression levels of IL-10 (at 2 ng/ml) and tumor necrosis factor (TNF)-alpha (at 10 ng/ml). In contrast, (1) the expression of cytokine (TNF-alpha) and (2) the generation of reactive oxygen species (ROS) induced by LPS were significantly up-regulated with KML co-treatment. In addition, KML itself increased the mRNA levels of IL-3 and IL-23; phagocytic uptake; the surface levels of co-stimulatory molecules (CD80 and CD86), pattern recognition receptors (PRRs) [such as dectin-1 and toll like receptor (TLR)-2] and adhesion molecules [beta1-integrins (CD29) and CD43]; and CD29-mediated cell adhesion events. Finally, according to co-treatment of D-galactose with KML under LPS-induced NO production conditions, KML inhibition seems to be mediated by binding to proteins with D-galactose. Therefore, these data suggest that KML may participate in regulating various macrophage-mediated innate and adaptive responses via binding to surface protein with D-galactose and that some of these may deserve in KML's therapeutic activities such as anti-tumor and anti-microbial effects.

Immunomodulatory effect of Hibiscus cannabinus extract on macrophage functions.

Hibiscus cannabinus L. (Malvaceae) (known as Kenaf) has long been used as a folk medicine in India and Africa for the treatment of blood and throat disorders, bilious conditions, fever and puerperium. In this study, therefore, we aimed either to demonstrate its ethnopharmacological activity by examining its macrophage function-regulating effects or to expand its therapeutic efficacy into other macrophage-mediated diseases. The total crude extract (EtOH extract) of Hibiscus cannabinus fresh leaves, prepared with 80% ethanol, significantly suppressed TNF-alpha production and the mRNA expression of interleukin (IL)-3 and IL-12 in the RAW264.7 cells, stimulated by lipopolysaccharide (LPS, 2.5 microg/ml). The secretion of inflammatory mediators (i.e., nitric oxide [NO], reactive oxygen species [ROS] and prostaglandin E(2) [PGE(2)]) was diminished by the EtOH extract. The extract induced the expression of heme oxygenase-1 (HO-1) mRNA, a potent cytoprotective molecule. The Kenaf extract suppressed both the phagocytic uptake and the expression of costimulatory molecules (CD80 and CD86) of LPS-activated RAW264.7 cells. It is interesting that Kenaf also down-regulated both the functional activation of beta1-integrin (CD29) and the LPS-induced up-regulation of the surface CD29 level. Taken together, these data suggest that Kenaf may be able to modulate macrophage-mediated responses and that some of the activities may contribute to expand its therapeutic usage.

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.