Experimental evidences and signal transduction pathways involved in the activation of NF-kappa B/Rel by angelan in murine macrophages

Angelica gigas: Signature Compounds, In Vivo Anticancer, Analgesic, Neuroprotective and Other Activities, and the Clinical Translation Challenges

Angelica gigas Nakai (AGN) root is a medicinal herbal widely used in traditional medicine in Korea. AGN root ethanolic extract dietary supplements are marketed in the United States for memory health and pain management. We comprehensively reviewed the anticancer, analgesic, pro-memory and other bio-activities of AGN extract and its signature phytochemicals decursin, decursinol angelate, and decursinol a decade ago in 2012 and updated their anticancer activities in 2015. In the last decade, significant progress has been made for understanding the pharmacokinetics (PK) and metabolism of these compounds in animal models and single dose human PK studies have been published by us and others. In addition to increased knowledge of the known bioactivities, new bioactivities with potential novel health benefits have been reported in animal models of cerebral ischemia/stroke, anxiety, sleep disorder, epilepsy, inflammatory bowel disease, sepsis, metabolic disorders, osteoporosis, osteoarthritis, and even male infertility. Herein, we will update PK and metabolism of pyranocoumarins, review in vivo bioactivities from animal models and human studies, and critically appraise the relevant active compounds, the cellular and molecular pharmacodynamic targets, and pertinent mechanisms of action. Knowledge gaps include whether human pyranocoumarin PK metrics are AGN dose dependent and subjected to metabolic ceiling, or metabolic adaptation after repeated use. Critical clinical translation challenges include sourcing of AGN extracts, product consistency and quality control, and AGN dose optimization for different health conditions and disease indications. Future research directions are articulated to fill knowledge gaps and address these challenges.

Polysaccharides from Polygonatum sibiricum Delar. ex Redoute induce an immune response in the RAW264.7 cell line via an NF-κB/MAPK pathway

The aim of this study was to examine the effect of polysaccharides from Polygonatum sibiricum (PSP) on RAW 264.7 cells together with the underlying signaling pathways. Water-soluble polysaccharides were extracted from Polygonatum sibiricum and the immunological activity/mechanism was explored in depth in RAW 264.7 cells. Our results demonstrated that PSP induced dendritic-like morphological changes in RAW 264.7 cells, and increased the production of nitric oxide, TNF-α and IL-6 in a dose-dependent manner. Mechanistic studies revealed that PSP promoted the accumulation of TNF-α and IL-6 mRNA and caused IκB-α degradation and NF-κB p65 translocation into the nucleus at both the transcriptional and translational levels. The expression of iNOS, COX-2, NF-κB and phosphorylated p38 MAPK was upregulated in PSP-treated RAW 264.7 cells. Water-soluble polysaccharides possess immunological activity and the immunostimulatory mechanism may be attributed to the NF-κB and p38 MAPK pathways similar to the mechanism of lipopolysaccharides.

Anti-cancer activity of Angelica gigas by increasing immune response and stimulating natural killer and natural killer T cells

Background

The polysaccharide component of Angelica gigas induces immuno-stimulatory effects on innate immune cells. However, it is unclear whether A. gigas’ adjuvant activity on the immune system can elicit anti-cancer responses.

Methods

A water-soluble immuno-stimulatory component of A. gigas was prepared. How this ISAg modulated the activation of innate immune cells such as dendritic cells (DCs) was examined. ISAg-induced cytotoxic activity via natural killer (NK) and NKT cells was also tested using a tumor-bearing mouse model.

Results

ISAg treatment induced nitric oxide (NO) production and cytokine gene expression involved in innate immune responses. ISAg activated macrophages and DCs to secrete cytokine IL-12, through the TLR4 signaling pathway. IL-12 plays a crucial role in ISAg-mediated NK and NKT cell activation. Thus, the anti-cancer activity of NK and NKT cells induced ISAg-mediated cytotoxicity of B16 melanoma cells in mice.

Conclusions

These results indicated that the natural ingredient, ISAg, has adjuvant activity to induce strong anti-cancer activity of NK and NKT cells in vivo.

Toll-like receptor 4-related immunostimulatory polysaccharides: Primary structure, activity relationships, and possible interaction models

Toll-like receptor (TLR) 4 is an important polysaccharide receptor; however, the relationships between the structures and biological activities of TLR4 and polysaccharides remain unknown. Many recent findings have revealed the primary structure of TLR4/MD-2-related polysaccharides, and several three-dimensional structure models of polysaccharide-binding proteins have been reported; and these models provide insights into the mechanisms through which polysaccharides interact with TLR4. In this review, we first discuss the origins of polysaccharides related to TLR4, including polysaccharides from higher plants, fungi, bacteria, algae, and animals. We then briefly describe the glucosidic bond types of TLR4-related heteroglycans and homoglycans and describe the typical molecular weights of TLR4-related polysaccharides. The primary structures and activity relationships of polysaccharides with TLR4/MD-2 are also discussed. Finally, based on the existing interaction models of LPS with TLR4/MD-2 and linear polysaccharides with proteins, we provide insights into the possible interaction models of polysaccharide ligands with TLR4/MD-2. To our knowledge, this review is the first to summarize the primary structures and activity relationships of TLR4-related polysaccharides and the possible mechanisms of interaction for TLR4 and TLR4-related polysaccharides.

Decursin inhibits osteoclastogenesis by downregulating NFATc1 and blocking fusion of pre-osteoclasts

Bone sustains its structure through dynamic interaction between osteoblastic cells and osteoclastic cells. But imbalance may lead to osteoporosis caused by overactivated osteoclast cells that have bone-resorbing function. Recently, herbs have been researched as major sources of medicines in many countries. In vitro and in vivo anti-osteoclastogenic activity of Angelica gigas NAKAI have been reported, but the biological activity of decursin, its major component in osteoclast differentiation is still unknown. Therefore, in this study, we explored whether decursin could affect RANKL-mediated osteoclastogenesis. The results showed that decursin efficiently inhibited RANKL-activated osteoclast differentiation by inhibiting transcriptional and translational expression of NFATc1, a major factor in RANKL-mediated osteoclastogenesis. Furthermore, decursin decreased fusion and migration of pre-osteoclasts by downregulating mRNA expression levels of DC-STAMP and β3 integrin, respectively. In addition, decursin prevents lipopolysaccharide (LPS)-induced bone erosion in vivo. In summary, decursin could prevent osteoclastogenesis and inflammatory bone loss via blockage of NFATc1 activity and fusion and migration of pre-osteoclasts, and it could be developed as a potent phytochemical candidate for treating pathologies of bone diseases.

Cancer Chemoprevention with Korean Angelica: Active Compounds, Pharmacokinetics, and Human Translational Considerations

Angelica gigas Nakai (AGN) is a major medicinal herb used in Korea and several other Asian countries. Traditionally, its dried root has been used to treat anemia, pain, infection and articular rheumatism, most often through boiling in water to prepare the dosage forms. AGN extract or AGN-containing herbal mixtures are sold in the US and globally as dietary supplements for pain killing, memory enhancement and post-menopausal symptom relief. Decursin (D) and its isomer decursinol angelate (DA) are the major chemicals in the alcoholic extracts of the root of AGN. The anti-cancer activity of AGN alcoholic extract has been established in a number of animal cancer models, including a transgenic model of prostate carcinogenesis. Cell culture structure-activity studies have uncovered distinct cellular and molecular effects of D and DA vs. their pyranocoumarin core decursinol (DOH) with respect to cancer cells and those associated with their microenvironment. Pharmacokinetic (PK) study by us and others in rodent models indicated that DOH is the major and rapid in vivo first-pass liver metabolite of D and DA. Cognizant of metabolic differences among rodents and humans, we carried out a first-in-human PK study of D/DA to inform the translational relevance of efficacy and mechanism studies with rodent models. The combined use of vigorous animal tests and human PK studies can provide stronger scientific rationale to inform design and execution of translational studies to move AGN toward evidence-based herbal medicine.

Characterization of polysaccharide from longan pulp as the macrophage stimulator

A 44.7-kDa polysaccharide LPIIa from longan pulp was mainly composed of →6)-Glc-(1→, →5)-Ara-(1→, →4)-Man-(1→ and →6)-Gal-(1→. It stimulated macrophage activation partlyviaTLR4 and TLR2, followed by p38 MAPK- and NF-κB-dependent signaling pathways.

Corn Silk Induced Cyclooxygenase-2 in Murine Macrophages

Stimulation of murine macrophages with corn silk induced cyclooxygenase (COX)-2 with secretion of PGE2. Expression of COX-2 was inhibited by pyrolidine dithiocarbamate (PDTC), and increased DNA binding by nuclear factor kappa B (NF-kappaB), indicating that COX-2 induction proceeds also via the NF-kappaB signaling pathway. A specific inhibitor of COX-2 decreased the expression level of inducible nitric oxide synthase (iNOS) stimulated by corn silk. PGE2 elevated the expression level of iNOS, probably via EP2 and EP4 receptors on the surface of the macrophages.

Immune-stimulatory and anti-inflammatory activities of Curcuma longa extract and its polysaccharide fraction

Background:

While curcuminoids have been reported to possess diverse biological activities, the anti-inflammatory activity of polar extracts (devoid of curcuminoids) of Curcuma longa (C. longa) has seldom been studied. In this study, we have investigated immune-stimulatory and anti-inflammatory activities of an aqueous based extract of C. longa (NR-INF-02) and its fractions in presence and absence of mitogens.

Materials and Methods:

Effects of NR-INF-02 (Turmacin™, Natural Remedies Pvt. Ltd., Bangalore, India) on proliferation, nitric oxide (NO), monocyte chemotactic protein-1 (MCP-1), interleukins (ILs) and prostaglandin (PGE₂) levels of mouse splenocytes and mouse macrophage (RAW264.7) cells were determined.

Results:

NR-INF-02 increased splenocytes number in presence and absence of lipopolysaccharide (LPS) or concanavalin A. Treatment of NR-INF-02 showed a significant increase of NO, IL-2, IL-6, IL-10, IL-12, interferon (IFN) gamma, tumor necrosis factor (TNF) alpha and MCP-1 production in unstimulated mouse splenocytes and mouse macrophages. Interestingly, NR-INF-02 showed potent inhibitory effect towards release of PGE₂ and IL-12 levels in LPS stimulated mouse splenocytes. Further, NR-INF-02 was fractionated into polysaccharide fraction (F1) and mother liquor (F2) to study their immune-modulatory effects. F1 was found to be more potent than F2 toward inhibiting PGE₂ and IL-12 in LPS stimulated splenocytes.

Conclusion:

Present findings revealed the novel anti-inflammatory property of NR-INF-02 and its polysaccharide fraction by inhibiting the secretion of IL-12 and PGE₂in vitro.

Early effects triggered by Larrea divaricata Cav. on murine macrophages at apoptotic concentrations

Decoction and infusion of Larrea divaricata were tested at apoptotic concentrations (1 and 4 mg/ml) on peritoneal murine macrophages. Consistent changes were observed after incubation with 4 mg/ml decoction. Phagocytosis of zymosan, lysosomal enzyme activity, nitric oxide production, TNF-alpha release, and expression of CD14, TLR4, and CR3 increased significantly. Decoction at 1 and 4 mg/ml increased the binding of LPS-FITC. Apoptosis triggered by L. divaricata decoction is consequence of cell activation. The effects are independent of nordihydroguaiaretic acid. This "activation and death" could be the mechanism of L. divaricata to exert the antituberculosis effect known in folk medicine.

Anti-inflammatory effect of So-Pung-Tang, a Korean traditional prescription for cerebral infarction patients

So-Pung-Tang (Sopung), a prescription composed of 14 herbal mixtures, has been widely used in the treatment of cerebral infarction in Oriental Medicine. However, the mechanisms by which the formula affects on the production of pro-inflammatory cytokines in cerebral infarction patients remain unknown yet. The levels of secretory protein of pro-inflammatory cytokines, including tumor necrosis factor (TNF)-alpha, interlukin (IL)-1beta, and IL-6, were significantly increased in both THP-1 differentiated macrophage-like cells (THP-1/M) and peripheral blood mononuclear cells (PBMCs) from cerebral infarction patients after stimulation. However, pretreatment with Sopung markedly inhibited the secretion of TNF-alpha and IL-6, but not IL-1beta, in lipopolysaccharide (LPS)-stimulated THP-1/M cells and PBMCs treated with LPS and phytohemagglutinin (PHA). Furthermore, Sopung significantly inhibited LPS-induced phosphorylation of extracellular signal-regulated kinase (ERK1/2) and c-jun N-terminal kinase (JNK), but not p38 in THP-1/M cells. These data indicate that Sopung may be beneficial in the cessation of inflammatory processes of cerebral infarction through suppression of ERK1/2 and JNK activation.

Immunostimulating activity of crude polysaccharide extract isolated from Curcuma xanthorrhiza Roxb

Curcuma xanthorrhiza Roxb., commonly known as Javanese turmeric, has been reported to possess a variety of biological activities, including anti-inflammatory effects, anticarcinogenic effects, wound healing effects, and serum cholesterol-lowering effects. CPE, crude polysaccharide extract isolated from the rhizome of C. xanthorrhiza using 0.1 N NaOH, consisted of arabinose (18.69%), galactose (14.0%), glucose (50.67%), mannose (12.97%), rhamnose (2.73%), and xylose (0.94%), with an average molecular weight of 33,000 Da. In the present study, we investigated the effect of CPE on nitric oxide (NO), hydrogen peroxide (H2O2), tumor necrosis factor-alpha (TNF-alpha), and prostaglandin E2 (PGE2) production in RAW 264.7 cells. The uptake of fluorescein-labeled Escherichia coli was measured to determine whether CPE stimulates the phagocytic activity of RAW 264.7 cells. CPE significantly increased the phagocytosis of macrophages and the release of NO, H2O2, TNF-alpha, and PGE2 in a dose-dependent manner, and showed a similar activity to lipopolysaccharide (LPS). To study the mechanisms of CPE, we examined induction of iNOS and COX-2. NO and PGE2 were produced as a result of stimulation of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) respectively. Both modulations of iNOS and COX-2 expression by CPE were evaluated by Western immunoblotting and RT-PCR. Since transcription of these enzymes is under the control of nuclear factor-kappa B (NF-kappaB), we assessed the phosphorylation of inhibitor kappaBalpha (IkappaBalpha) through Western immunoblotting. CPE clearly induced phosphorylation of IkappaBalpha, suggesting a role as an NF-kappaB activator. Taking all this together, we conclude that CPE isolated from Curcuma xanthorrhiza stimulates the immune functions of macrophages, which is mediated in part by specific activation of NF-kappaB.

Botanical polysaccharides: macrophage immunomodulation and therapeutic potential

Botanical polysaccharides exhibit a number of beneficial therapeutic properties, and it is thought that the mechanisms involved in these effects are due to the modulation of innate immunity and, more specifically, macrophage function. In this review, we summarize our current state of understanding of the macrophage modulatory effects of botanical polysaccharides isolated from a wide array of different species of flora, including higher plants, mushrooms, lichens and algae. Overall, the primary effect of botanical polysaccharides is to enhance and/or activate macrophage immune responses, leading to immunomodulation, anti-tumor activity, wound-healing and other therapeutic effects. Furthermore, botanical and microbial polysaccharides bind to common surface receptors and induce similar immunomodulatory responses in macrophages, suggesting that evolutionarily conserved polysaccharide structural features are shared between these organisms. Thus, the evaluation of botanical polysaccharides provides a unique opportunity for the discovery of novel therapeutic agents and adjuvants that exhibit beneficial immunomodulatory properties.

Activation of mitogen-activated protein kinases and AP-1 by polysaccharide isolated from the radix of Platycodon grandiflorum in RAW 264.7 cells

The root of Platycodon grandiflorum has been widely used for the treatment of various diseases in oriental medicine. Our previous study showed that the PG, a polysaccharide isolated from P. grandiflorum, activates macrophages via Toll-like receptor 4 (TLR4). However, the associated biological mechanisms are not fully understood. To elucidate the molecular mechanism responsible for the macrophage activation, we investigated the effect of PG on the activity of mitogen-activated protein kinases (MAPKs) and activator protein-1 (AP-1) in RAW 264.7 cells, a murine macrophage cell line. Treatment of RAW 264.7 cells with PG produced a marked induction of AP-1 DNA binding activity. Moreover, all three MAPKs were activated by PG, and PG-induced activation of MAPKs was abrogated by the treatment of PD98059, curcumin, and SB203580, specific inhibitors of MEK-1/2, stress-activated protein kinases/jun N-terminal kinase (SAPK/JNK), and p38 MAP kianse, respectively. The induction of AP-1 DNA binding activity by PG was also inhibited by these MAPK inhibitors. Moreover, supershift analysis identified that JunB and Fra-1 are major components involved in the PG-mediated induction of AP-1 DNA binding. Additionally, curcumin and SB203580 suppressed PG-induced production of nitric oxide (NO) and tumor necrosis factor-alpha (TNF-alpha), whereas PD98059 showed an inhibitory effect only on the TNF-alpha production. Taken together, these results suggest that macrophage activation by PG is mediated, at least in part, by MAPKs and AP-1.

Toll-like receptor 4-dependent activation of macrophages by polysaccharide isolated from the radix of Platycodon grandiflorum

Platycodon grandiflorum, a traditional oriental herbal medicine, is known to have immunostimulatory and antitumor effects. PG, a polysaccharide isolated from P. grandiflorum, has been reported to activate macrophages and B cells. Here, we investigated the membrane receptor and intracellular signaling responsible for the activation of macrophages by PG. PG induced the production of nitric oxide (NO) and the mRNA expression of iNOS in RAW 264.7 cells. To investigate the membrane receptor involved in the activation of NO production, we examined the effect of PG on the production of NO in mouse peritoneal macrophages isolated from wild type C3H/HeN and functional Toll-like receptor 4 (TLR4)-deficient C3H/HeJ mice. PG induced NO production by macrophages isolated from C3H/HeN mice, but had no effect on NO production by macrophages isolated from C3H/HeJ mice. Moreover, monoclonal antibodies directed to TLR4 blocked PG-mediated induction of NO production. In addition, LBP and sCD14 was also found to be involved in the activation of NO production by PG. To further investigate, we examined the effect of PG on the activation of DNA binding of NF-kappa B, which is a downstream transcriptional regulator of TLR4. PG caused degradation of I kappa B and activation of DNA binding of NF-kappa B. In addition, TPCK, a specific NF-kappa B inhibitor, abolished PG-mediated induction of DNA binding of NF-kappa B, production of NO and mRNA expression of iNOS, demonstrating the involvement of NF-kappa B in PG-mediated macrophage activation. Taken together, these results suggest that PG-mediated induction of NO production and iNOS mRNA expression in macrophages is mediated, at least in part, by TLR4/NF-kappa B signaling pathway.

Mitogen-activated protein (MAP) kinases mediate PMMA-induction of osteoclasts

Inflammatory osteolysis induced by implant-derived wear debris is associated with infiltration of various cell-types to the implant-bone interface leading to abundant secretion of pro-inflammatory cytokines and activation of proteinases that together lead to propagation of the localized inflammatory response and periprosthetic bone erosion. Tumor necrosis factor family members are considered to be direct mediators of inflammation and osteolysis. These cytokines exert their osteoclastic effects via activation of the transcription factor NF-kappaB and certain MAP kinases, including c-Jun, Erks and p38, all known to be essential for the development of osteoclasts. We have recently documented that the osteoclastogenic cytokines TNF and RANKL play a pivotal role in the development of inflammatory osteolysis. We have also found that PMMA particles stimulate osteoclastogenesis, at least in part, by induction of RANKL, TNF, and by activation of the transcription factor NF-kappaB. More importantly, our data indicate that inhibitors of the osteoclastogenic factors, TNF and RANKL abrogate particle-induced osteoclastogenesis. In the current study, we investigated if PMMA particles activate MAP kinases, and the potential role of these kinases as mediators of osteolysis. Using kinase assays, we show that in osteoclast precursors, PMMA particles markedly and rapidly activate p38 and ERK MAP kinases. This activation was specific, evident by complete blockade with specific inhibitory compounds. Similarly, we show that PMMA particles activate the JNK pathway, which is known to be involved in inflammatory and osteoclastogenic events. We also show that p38 MAP kinase regulates PMMA-activation of NF-kappaB, thus providing a possible mechanism for particle action in osteoclast precursors. Finally, we provide evidence that specific inhibitors of MAP kinases are capable of inhibiting PMMA-stimulated osteoclastogenesis. These data provide evidence that MAP kinases are potent mediators of particle-induced osteoclastogenesis.

Effect of an acidic heteropolysaccharide (ARAGAL) from the gum of Anadenanthera colubrina (Angico branco) on peritoneal macrophage functions

Brazilian flora are a source of interesting polysaccharides which, either in their native state or when submitted to structural modifications, might have potential applications as biological response modifiers (BRM). A complex acidic heteropolysaccharide, containing mainly galactose and arabinose (ARAGAL), isolated from the gum of the native leguminous tree Anadenanthera colubrina (Angico branco), was studied for its immunological properties on peritoneal exudate cells, namely their superoxide anion production, phagocytic activity, morphological alterations and percentage content of activated macrophages. Activation of macrophages showing increased cytoplasm, bright and large nuclei, various cytoplasmatic projections and spreading ability, was detected following in vitro cell exposure to ARAGAL or in cells obtained from treated animals. In vitro exposure to ARAGAL increased the occurrence of activated macrophages in a time- and a dose-dependent pattern, since approximately 82% of the cells were activated in the presence of 300 microg/ml of ARAGAL after 24 h of incubation and approximately 91% after 48 h. The occurrence of activated macrophages was also evident in cell preparations from ARAGAL-treated mice, their percentage showing a dose-dependent pattern. There were approximately 60, 75 and 75% following treatment with 100, 250 and 500 mg/kg of ARAGAL, respectively. A phagocytic assay showed that 25 microg/ml ARAGAL was sufficient to impose a maximum phagocytic ability, although this effect was dose-dependent. O(2)(-) production by macrophages from ARAGAL-treated mice was 70% higher than that of cells from untreated mice. Moreover, cells from treated mice responded to PMA, the effect being 25% higher than that of the control using untreated mice. These results thus suggest a possible role of ARAGAL from A. colubrina as a BRM.

Toll-like receptor-mediated activation of B cells and macrophages by polysaccharide isolated from cell culture of Acanthopanax senticosus

We investigated the mechanism of the immunomodulatory action of polysaccharide (ASP) isolated from a cell culture of Acanthopanax senticosus. ASP was found to directly increase the proliferation and differentiation of B cells, and the cytokine production of macrophage, but not the proliferation and cytokine production of T cells. Since ASP cannot penetrate the cell membrane due to its large molecular mass, such cellular activation may be caused by the surface binding of ASP to receptors expressed on B cells and macrophages. The possibility that TLRs, which are known to be involved in immune-related responses, may be the receptor(s) of ASP was investigated. The immunomodulating activities of ASP on the B cells and macrophages of C3H/HeJ mice, expressing a defective toll-like receptor (TLR)-4, were decreased versus the corresponding cells from C3H/HeN mice. In addition, the activities of ASP on B cells and macrophages were significantly reduced by treating the cells with antibodies to TLR4 and TLR2 prior to ASP, suggesting that both of them are the possible receptors of ASP. The ligation of TLRs induced by ASP was able to activate mitogen-activated protein kinases (MAPKs), such as Erk1/2, p38 and JNK, and the transcription factor NF-kappaB. Although ASP was shown to activate the TLR signaling cascades in the same manner as lipopolysaccharide (LPS), these two could be differentiated by the finding that polymyxin B (PMB), a specific inhibitor of LPS, did not significantly affect the activities of ASP on B cells and macrophages. Taken together, our results demonstrate that ASP, isolated from a cell culture of A. senticosus, activates B cells and macrophages by interacting with TLRs and leading to the subsequent activation of mitogen-activated protein kinases and NF-kappaB.