Identification of intracellular activation mechanism of rhamnogalacturonan-I type polysaccharide purified from Panax ginseng leaves in macrophages and roles of component sugar chains on activity.

This study aimed to investigate the mechanisms underlying intracellular signaling pathways in macrophages in relation to the structural features of rhamnogalacturonan (RG) I-type polysaccharide (PGEP-I) purified from Panax ginseng leaves. For this investigation, we used several specific inhibitors and antibodies against mitogen-activated protein kinase (MAPK), nuclear factor-kappa B (NF-κB), and pattern recognition receptors (PRRs). Furthermore, we investigated the roles of component sugar chains on immunostimulating activity through a sequential enzymatic and chemical degradation steps. We found that PGEP-I effectively induced the phosphorylation of several MAPK- and NF-κB-related proteins, such as p38, cJun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK), and p65. Particularly, immunocytochemistry analysis confirmed the PGEP-I-induced translocation of p65 into the nucleus. Furthermore, the breakdown of PGEP-I side chains and main chain during sequential enzymatic and chemical degradation reduced the PGEP-I-induced macrophage cytokine secretion activity. IL-6, TNF-α, and NO secreted by macrophages are associated with several signaling pathway proteins such as ERK, JNK, and NF-κB and several PRRs such as dectin-1, CD11b, CD14, TLR2, TLR4, and SR. Thus, these findings suggest that PGEP-I exerts potent macrophage-activating effects, which can be attributed to its typical RG-I structure comprising arabinan, type II arabinogalactan, and rhamnose-galacturonic acid repeating units in the main chain.

Red Ginseng Extract and γ-Aminobutyric Acid Synergistically Enhance Immunity Against Cancer Cells and Antitumor Metastasis Activity in Mice.

The effects of combined administration of red ginseng (RG) extracts and gamma-aminobutyric acid (GABA) on immunostimulatory activity and tumor metastasis inhibition were investigated in mice. For the immunostimulatory activity, splenocyte proliferation, natural killer (NK) cell activity, including the production of granzyme B (GrB) and interferon gamma (IFN-γ), and serum level of cytokine such as IFN-γ, interleukin (IL)-17, and IL-21 were assessed. Peyer's patch cells obtained from mice administered with RG+GABA were cultured, and the cytokine level in the culture supernatant and bone marrow (BM) cell proliferation activity were examined. The proliferative activity of splenocytes was significantly higher in the RG-GABA treatment group than in RG or GABA alone (P < .05). In the experimental tumor metastasis model, oral administration of RG+GABA showed a higher antitumor metastatic effect compared to that of RG or GABA alone. Oral administration of RG+GABA significantly augmented NK cell-mediated cytotoxicity against YAC-1 tumor cells. In addition, the production of GrB and IFN-γ was stimulated in the culture supernatant of NK cells and YAC-1 cells. Serum concentrations of IFN-γ, IL-17, and IL-21 in mice with RG+GABA were significantly higher compared to the corresponding blood levels in mice administered with RG or GABA alone. The RG+GABA group showed significant BM cell proliferation and increased production of IL-6 and granulocyte-macrophage colony-stimulating factor compared to that in the monotherapy groups. Therefore, RG may have a synergistic effect with GABA for enhancing the host defense system such as BM proliferation and NK cell activity in a tumor metastasis model.

Tumor inhibitory effect via immunostimulating activities of a rhamnogalacturonan-I-rich polysaccharide isolated from turmeric (Curcuma longa L.).

In this study, a turmeric polysaccharide (TP-0) was isolated through hot water extraction and ethanol precipitation to produce a novel active polysaccharide from turmeric other than curcuminoids. TP-0 was found to be primarily composed of eight different monosaccharides, such as galactose (15.9%), galacturonic acid (15.2%), arabinose (11.4%), and rhamnose (9.7%), which are typical rhamnogalacturonan (RG)-I sugars. When stimulated with TP-0, peritoneal macrophages secreted a variety of immunostimulatory cytokines. In addition, intravenous and oral administration of TP-0 significantly enhanced the natural killer (NK) cells and cytotoxic T lymphocyte (CTL)-mediated cytotoxicity against tumor cells. In an assay for lung cancer induced by Colon26-M3.1 carcinoma, prophylactic intravenous and oral administration of TP-0 effectively inhibited lung cancer. These findings reveal that TP-0, a typical RG-I-type polysaccharide that is isolated from turmeric, has potent anti-metastatic activities, and these activities are linked to various immunological factors such as macrophages, NK cells, and CTL. PRACTICAL APPLICATIONS: Many studies related with turmeric have only focused that a curcuminoid of turmeric has beneficial effects on human health system. Nevertheless, in this study, it was confirmed that polysaccharide isolated from turmeric showed potent anti-cancer effects via activities of various immunological factors such as macrophages, NK cells, and CTL. These results suggest the high potential for development value of turmeric as a new candidate for immunostimulating-related health functional food ingredients.

Immunostimulating and intracellular signaling pathways mechanism on macrophage of rhamnogalacturonan-I type polysaccharide purified from radish leaves.

In this study, the intracellular signaling pathways involved in macrophage activation through the RG-I-type polysaccharide (REP-I) purified from radish leaves were elucidated. The gene expression and secretion of immune-related factors such as interleukin (IL)-6, tumor necrosis factor (TNF)-α, and nitrogen oxide (NO) from macrophages were enhanced by the addition of REP-I. Moreover, immunoblotting and immunocytochemistry analyses indicated that REP-I dose-dependently phosphorylated the mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) pathways. An investigation using different inhibitors revealed that the effect of REP-I on NO secretion was mostly promoted by c-Jun N-terminal kinase (JNK) and NF-κB. Furthermore, the secretion of IL-6 was mostly induced via extracellular-signal-regulated kinase (ERK), JNK, and NF-κB. TNF-α secretion was mostly induced via NF-κB. In contrast, an investigation using anti-pattern recognition receptor (PRR) antibodies revealed that the effect of REP-I on the secretion of NO was mostly related with dectin-1, scavenger receptor (SR), toll-like receptor (TLR)2, TLR4, CD14, and CD11b. Furthermore, the secretion of IL-6 was mostly involved with SR, and the secretion of TNF-α was mostly relevance to TLR2. In conclusion, it is affirmed that immunostimulatory activation of macrophage of REP-I purified from radish leaves was deeply associated with several PRR and phosphorylating MAPK and NF-κB.

Clarification of the structural features of Rhamnogalacturonan-I type polysaccharide purified from radish leaves.

Determining the structure of REPI, an immunostimulatory polysaccharide fraction from radish leaves, is an important health objective. Herein, we show that REP-I contains nine different monosaccharides, including GalA (22.2%), Gal (32.6%), Ara (27.5%), and Rha (10.2%) as main sugars. REP-I was also reacted with ß-glucosyl Yariv reagent (29.8%), suggesting the presence of the arabino-ß-3,6-galactan. Furthermore, methylated-product analysis revealed that REP-I contains 13 different glycosyl linkages, including 4-linked GalpA (21.0%), 2,4-linked Rhap (7.0%), 4-linked Galp (5.8%), 5-linked Araf (10.1%), and 3,6-linked Galp (7.9%), which are characteristic of RG-I. Microstructural information was obtained by sequential degradation using four linkage-specific glycosylases and ß-elimination, with fragments analyzed on the basis of sugar composition, methylation, and MS/MS spectra. The results show that the immunostimulatory activity of REP-I is possibly due to the structure of RG-I, which is composed of a main chain with repeating [→2)-Rhap-(1 â†’ 4)-GalpA-(1→] linkage units and three side-chains: a branched α(1 â†’ 5)arabinan, a ß(1 â†’ 4)galactan, and arabino-ß-3,6-galactan, which are branched at the C(O)4 position of each Rha residue in the REP-I main chain.

Effect of Characterized Green Tea Extraction Methods and Formulations on Enzymatic Starch Hydrolysis and Intestinal Glucose Transport.

The purpose of the current study was to investigate the effect of various characterized green tea extracts (GTEs) according to extraction methods on enzymatic starch hydrolysis and intestinal glucose transport. Codigestion of wheat starch with water extract (WGT) or ethanol extract formulated with green tea polysaccharides and flavonols (CATEPLUS) produced 3.4-3.5 times higher resistant starch (RS) than wheat starch only. Its microstructures were changed to spherical shapes and smooth surfaces as shown by scanning electron microscopy (SEM) results. According to Fourier transform infrared (FT-IR) spectra, the absorption peak of O-H stretching was red-shifted in WGT or CATEPLUS. The results confirmed that hydrogen bonds were formed between starch granules and polysaccharides in WGT or CATEPLUS. Intestinal glucose transport subsequently measured after in vitro digestion was mostly suppressed in CATEPLUS. Gene expression of the glucose transporter protein, particularly SGLT1, was significantly inhibited by addition of CATEPLUS (p < 0.05). Results from the current study suggest that co-intake of green tea extracts formulated with green tea polysaccharides and flavonols could be a potentially useful means to delay blood glucose absorption when consuming starchy foods.

Layers of Uranium Phosphate Nanorods and Nanoplates Encrusted on Fungus Cladosporium sp. Strain F1 Hyphae.

The hyphae of Cladosporium sp. strain F1 (CFGR 2020-301-00084) were heavily encrusted with pre-synthesized uranium phosphate minerals under a wide range of pH conditions. SEM and TEM images showed that nanorods and nanoplates of uranium phosphate minerals at pH 4 and 5 and at pH 6, 7, and 8, respectively, were tightly adsorbed along the hyphae of Cladosporium sp. strain F1, while only a few uranium phosphate minerals were observed on the hyphae of Aspergillus niger VKMF 1119. Based on the physical mobility and chemical stability of uranium phosphate minerals under in situ oxidizing environmental conditions, the application of Cladosporium sp. strain F1 has potential as a novel strategy for the remediation of uranium contamination in sediments and aquifers under a wide range of pH conditions where larger amounts of phosphate are present in the environment.

Characterized Polysaccharides from Green Tea Inhibited Starch Hydrolysis and Glucose Intestinal Uptake by Inducing Microstructural Changes of Wheat Starch.

The purpose of the current study was to investigate the effect of green tea ethanol extract (GTE) and polysaccharide fractions from green tea (PFGs) on the hydrolysis of wheat starch, microstructural changes, and intestinal transport of glucose. The amount of resistant starch (RS) was significantly lowered in the water-soluble polysaccharide (WSP), water-soluble polysaccharide-pectinase (WSP-P), and water-insoluble polysaccharide-alkali soluble (WISP-Alk-Soluble; p < 0.05). The microstructures of gelatinized wheat starch granules with WSP, WSP-P, and WISP-Alk-Soluble were spherical with small cracks. The amount of intestinal transported glucose from digested wheat starch was 2.12-3.50 times lower than the control group. The results from the current study suggest that water- and alkali-soluble PFGs could be potential ingredients to lower starch hydrolysis as well as to control the postprandial blood glucose level when foods that contain starch are consumed.

Anti-asthma and antitussive effects of a fermented extract of a mixture of Ramulus mori, Anthriscus sylvestris, and Salvia plebeian.

Respiratory immunity is getting more important recently due to outbreak of respiratory diseases and increasing the concentration of fine dust. The aim of this study was to investigate respiratory protection effect of a fermented extract of medicinal plants (FEMP) containing Ramulus mori, Salvia plebeia, and Anthriscus sylvestris. The expression levels of IL-8 and IL-17 in LPS/poly-L-arginine (PLA) and FEMP-cotreated A549 cells were lower than those in LPS/PLA only-treated cells. The levels of IgE, IL-17, and IL-4 in the bronchoalveolar lavage fluid (BALF) and serum of FEMP-treated mice with ovalbumin/LPS-induced asthma were lower than the control levels. The lung inflammation score and the number of inflammatory cells in the BALF decreased by FEMP treatment. In the citric acid-induced coughing guinea pig, the FEMP treatment decreased the number of coughs. Therefore, FEMP shows anti-asthmatic and antitussive activities without hepatotoxicity and can be used as a compound aiming to improve respiratory health. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10068-021-00955-3.

Elucidation of the microstructure of an immuno-stimulatory polysaccharide purified from Korean red ginseng using sequential hydrolysis.

The elucidation of the structural characteristics of polysaccharides from natural sources is generally difficult owing to their structural complexity and heterogeneity. In our previous study, an immuno-stimulatory polysaccharide (RGP-AP-I) was isolated from Korean red ginseng (Panax ginseng C.A. Meyer). The present study aims to elucidate the structural characteristics of RGP-AP-I. Sequential enzyme hydrolysis was performed using four specific glycosylases, and chemical cleavage via ß-elimination was carried out to determine the fine structure of RGP-AP-I. The degraded fragments were chemically identified using various chromatographic and spectrometric analyses, including HPLC-UVD, GC-MS, and tandem mass spectrometry. The results indicated that RGP-AP-I comprises a rhamnogalacturonan I (RG-I) backbone with repeating disaccharide units [→2)-Rhap-(1 â†’ 4)-GalAp-(1→] and three side chains substituted at the C(O)4 position of the rhamnose residue in the backbone. The three side chains were identified as a highly branched α-(1 â†’ 5)-arabinan, a branched ß-(1 â†’ 4)-galactan, and an arabino-ß-3,6-galactan. Our results represent the first findings regarding the fine structure of the immuno-stimulatory polysaccharide RG-AP-I isolated from red ginseng.

Immunostimulatory Activity of Polysaccharides Extracted from Celosia cristata Flowers.

Macrophages play a major role in innate immune responses by producing a variety of immune mediators and cytokines. The stimulation of macrophages by natural products may lead to an enhanced innate immune system. This study evaluated the immunostimulatory effects of a polysaccharide-rich crude fraction of Celosia cristata L. flowers (CCP) on murine macrophages. CCP treatment induced the production of inducible nitric oxide synthase, cyclooxygenase-2, and cytokines by macrophages. Mechanistically, the activation of mitogen-activated protein kinases, NF-κB and toll-like receptor 4 were found to be associated with the stimulatory functions of CCP. CCP was found to be primarily composed of galacturonic acid and glucose in addition to small amounts of arabinose and galactose. This study demonstrated that CCP may enhance the innate immune responses and potentially improve the immune functions in the body.

Characterization, prebiotic and immune-enhancing activities of rhamnogalacturonan-I-rich polysaccharide fraction from molokhia leaves.

Plant-derived polysaccharides possess potential health benefits that improve intestinal health and the immune system. Molokhia leaves have a large amount of mucilage polysaccharide; in the present study, crude polysaccharide extract was prepared from molokhia leaves. The molecular weight of molokhia leaf polysaccharide fraction (MPF) was estimated to be 51.2 × 103 Da. Polysaccharide was methylated and the structure of MPF was mainly composed of rhamnogalacturonan-I structure with side chains, such as galactans and linear glucan (starch), as shown by GC-MS analysis. To study the biofunctional effects of MPF, its prebiotic and intestinal immune-enhancing activities were assayed in vitro. MPF exhibited good prebiotic activity, as shown by its high prebiotic scores, and increased contents of total short-chain fatty acids on five probiotic strains. In addition, MPF showed immune-enhancing activity on Peyer's patches, as revealed by the high bone marrow cell proliferating activity and production of immunoglobulin A and cytokines. These results demonstrate that MPF may be a potential beneficial prebiotic and intestinal immune-enhancer, which may have wide implications in the food industry.

Ginseng berry polysaccharides on inflammation-associated colon cancer: inhibiting T-cell differentiation, promoting apoptosis, and enhancing the effects of 5-fluorouracil.

BACKGROUND: Ginseng is a commonly used herbal medicine in treating various medical conditions. Chronic gut inflammation is a recognized factor for the development of colorectal cancer (CRC). In this project, Asian ginseng berry polysaccharide preparations were used to assess their effects on CRC and related immune regulation mechanisms. METHODS: Ginseng berry polysaccharide extract (GBPE) and purified ginseng berry polysaccharide portion (GBPP) were used to evaluate their activities on human HCT-116 and HT-29 CRC cell proliferation. Interleukin-8 secretion analysis was performed on HT-29 cells. Naive CD4 cell isolation and T-helper cell differentiation were performed and determined using flow cytometry for Th1 and Treg in addition to cell cycle and apoptotic investigation. RESULTS: GBPE and GBPP significantly inhibited interleukin-8 secretion and cancer cell proliferation, inhibited CD4+IFN-γ+ cell (Th1) differentiation, and decreased CD4+FoxP3+ cell (Treg) differentiation. Compared to the GBPE, GBPP showed more potent antiinflammatory activities on the malignant cells. This is consistent with the observation that GBPP can also inhibit Th1-cell differentiation better, suggesting that it has an important role in antiinflammation, whereas Treg cells hinder the body's immune response against malignancies. Supported by cell cycle and apoptosis data, GBPE and GBPP, at various degrees, remarkably enhanced the anticancer activities of 5-fluorouracil. CONCLUSION: Data from this project suggested that Asian ginseng berry potentially has clinical utility in managing enteric inflammation and suppressing CRC through immunomodulation mechanisms.

Signaling pathway and structural features of macrophage-activating pectic polysaccharide from Korean citrus, Cheongkyool peels.

To characterize the immuno-stimulating ingredient from the Korean citrus, Cheongkyool, a crude polysaccharide (CCE-0) was isolated from the pectinase digests of Cheongkyool peels, from which the complex polysaccharide CCE-I was purified to homogeneity by gel filtration. CCE-I highly enhanced the production of IL-6, TNF-α, and NO in RAW 264.7 cell lines. It augmented the mRNA expression of IL-6, TNF-α, and iNOS in a dose-dependent manner. Moreover, CCE-I dose-dependently induced phosphorylation of MAPKs and NF-κB related proteins and led to the nuclear translocation of p65. The effect of CCE-I on NO and IL-6 production was suppressed by treatment with specific antibodies for TLR2, TLR4, and scavenger receptors. Conversely, the primary structure of CCE-I that exhibited potent immunostimulatory activity was characterized by sugar composition, linkage analysis, and oligosaccharide analysis after ß-elimination. The results suggested that CCE-I may be a rhamnogalacturonan-I type, highly branched polysaccharide with short arabinan and galactan side chains.

Immunostimulating and Antimetastatic Effects of Polysaccharides Purified from Ginseng Berry.

Ginseng root has been used in traditional oriental medicine for the enhancement of immune system function. The immunostimulatory effects of ginseng berry polysaccharides, however, remain unclear. Effects of polysaccharides from ginseng berry on the activation of natural killer (NK) cells and inhibition of tumors are reported. A crude polysaccharide was isolated from ginseng berry as a ginseng berry polysaccharide portion (GBPP) and was further fractionated using gel filtration chromatography to obtain the three polysaccharide fractions GBPP-I, -II and -III. GBPP-I consisted of mainly galactose (46.9%) and arabinose (27.5%). GBPP-I showed a high dose-dependent anticomplementary activity. Stimulation of murine peritoneal macrophages by GBPP-I showed the greatest enhancement of interleukin (IL)-6 and IL-12 and tumor necrosis factor (TNF)- α production. In addition, an ex vivo assay of natural killer (NK) cell activity showed that oral ( p.o.) administration of GBPP-I significantly increased NK cell cytotoxicity in YAC-1 tumor cells and production of granzyme B. Prophylactic intravenous ( i.v.) and p.o. administration of GBPP-I significantly and dose-dependently inhibited lung metastatic activity in B16BL6 melanoma cells. Depletion of NK cells after injection of rabbit anti-asialo GM1 partially abolished the inhibitory effect of GBPP-I on lung metastasis, indicating that NK cells play an important role in anticancer effects. GBPP-I exerts a strong immune-enhancing activity and can prevent cancer metastasis through activation of NK cells and other immune-related cells.

Rhamnogalacturonan-I-Type Polysaccharide Purified from Broccoli Exerts Anti-Metastatic Activities Via Innate Immune Cell Activation.

To examine the anti-metastatic activities of polysaccharides in broccoli, purified polysaccharides (BCE-I, -II, and -III) were isolated by fractionation of broccoli enzyme extracts and subsequent ethanol precipitation. BCE-I mainly consisted of galactose and arabinose, whereas BCE-II mainly consisted of galacturonic acid and rhamnose, and BCE-III mainly consisted of rhamnose and galactose. Of the three fractions, stimulation of murine peritoneal macrophages by BCE-I showed the greatest enhancement of tumor necrosis factor-α, interleukin (IL)-12, and IL-6 secretion. In addition, intravenous (i.v.) administration of BCE-I enhanced the lethal activity of natural killer (NK) cells on YAC-1 tumor cells significantly and dose-dependently in an ex vivo experiment of NK cell activity. In an experimental model using lung metastasis of Colon26-M3.1 carcinoma cells, prophylactic i.v. and oral administration of BCE-I significantly and dose-dependently inhibited lung metastatic activity. Furthermore, the inhibitory activity of BCE-1 on lung metastasis partially disappeared when NK cell function was removed through treatment of rabbit anti-asialo GM1. These results indicated that BCE-I has potent antitumor metastatic activity, and that its anti-metastatic activity has relevance to the stimulation of NK and other immune cells.

Signaling pathways associated with macrophage-activating polysaccharides purified from fermented barley.

Barley is commonly used in many food and health products. We have previously demonstrated the macrophage-stimulating properties of polysaccharides derived from fermented barley. In this study, three polysaccharide fractions (BF-I-III) were purified from fermented barley and their monosaccharide composition was analyzed. Their immune-stimulatory activities and intracellular signaling pathways were also studied in RAW264.7 cells. Among the three fractions, BF-I exhibited enhanced macrophage activation properties, such as inducing the production of IL-6, IL-12, and TNF-α. However, BF-II and BF-III showed moderate effects on RAW 264.7 cells. BF-I treatment led to the phosphorylation of MAPKs, NF-κB, and c-Jun (major component of AP-1 transcription factor) and induced the nuclear translocation of p65 in RAW264.7 cells. In addition, experiments with neutralizing antibodies showed that Dectin-1, toll-like receptor (TLR) 4, scavenge receptor (SR), and CD14 were mainly involved in the stimulation of nitric oxide (NO) production by BF-I which was suppressed by the inhibition of JNK phosphorylation. These findings suggest that BF-I, isolated from fermented barley, has an immune potentiation activity on macrophages, where it activates the JNK signaling pathway via several macrophage receptors including dectin-1, TLR4, SR, and CD14.

Hypoglycemic potential of whole green tea: water-soluble green tea polysaccharides combined with green tea extract delays digestibility and intestinal glucose transport of rice starch.

Green tea is being studied extensively for its postprandial hypoglycemic effect due to its abundant catechins. Along with catechins, water-soluble green tea polysaccharides are also currently gaining attention due to their natural hypoglycemic properties. The current study investigated the combinational effect of green tea extract (GTE) and crude green tea polysaccharides (CTP) in inhibiting glucose transport after digestion of rice starch, using an in vitro digestion model with a Caco-2 cell. Co-digestion of rice starch with GTE (16.09 ± 1.02 g L-1), CTP (16.83 ± 0.81 g L-1), or GTE + CTP (17.79 ± 0.80 g L-1) hydrolyzed less starch into glucose compared with the control (18.24 ± 0.45 g L-1). Glucose transport from digesta to the Caco-2 cell after 120 min incubation was significantly inhibited with GTE + CTP (53.26 ± 4.34%). Gene expression of intestinal glucose transporters, which included sodium-dependent glucose transporter (SGLT1) and glucose transporter 2 (GLUT2), was not altered by GTE, CTP or GTE + CTP, except for the GTE-mediated upregulation of GLUT2. It is concluded that GTE + CTP lowered digestibility of rice starch with glucose and also delayed glucose uptake to the intestinal epithelium. This finding suggests a potential for green tea polysaccharides as a natural postprandial hypoglycemic substance.

Stimulation of Innate Immune Function by Panax ginseng after Heat Processing.

Panax ginseng Meyer has been used for the treatment of immune diseases and for strengthening the immune function. In this study, we evaluated the innate immune-stimulating functions and action mechanisms of white ginseng (WG) and heat-processed ginseng (HPG) in RAW264.7 cells. According to LC-MS analysis results, WG contained typical ginsenosides, such as Rb1, Rc, Rb2, Rd, and Rg1, whereas HPG contained Rg3, Rk1, and Rg5 as well as typical ginsenosides. HPG, not WG, enhanced NF-κB transcriptional activity, cytokine production (IL-6 and TNF-α), and MHC class I and II expression in RAW264.7 cells. In addition, HPG phosphorylated MAPKs and NF-kB pathways. In experiments with inhibitors, the ERK inhibitor completely suppressed the effect of HPG on IL-6 and TNF-α production. HPG-induced c-Jun activation was suppressed by an ERK inhibitor and partially suppressed by JNK, p38, and IκBα inhibitors. Collectively, these results suggested that HPG containing Rg3, Rg5, and Rk1 increased macrophage activation which was regulated by the ERK/c-Jun pathway in RAW264.7 cells.

Immunoadjuvant activity in mice of polysaccharides isolated from the leaves of Panax ginseng C.A. Meyer.

Our previous study showed polysaccharide (GS-P) isolated from the leaves of Panax ginseng C.A. Meyer possessed anti-tumor metastatic activity in mouse model. In this study, we evaluated the immunoadjuvant effect of GS-P on the induction of humoral and cellular immune responses against ovalbumin (OVA) in mice. When mice were immunized subcutaneously with OVA admixed with or without GS-P, the OVA+GS-P group showed significantly higher antibody production than the group immunized with OVA alone. This suggests that GS-P has the ability to enhance the adaptive immune response. In addition, the OVA+GS-P+FIA (Freund's incomplete adjuvant) group induced higher levels of antigen-specific IgG1 and IgG2b antibodies than the OVA+FIA group. The culture supernatant obtained from the splenocytes of mice immunized with OVA+GS-P+FIA showed higher levels of OVA-specific Th1-type (IL-2, IFN-γ, GM-CSF) and Th2-type (IL-10) cytokines. Following in vitro analysis of T cell proliferation, the splenocytes of mice treated with OVA+GS-P+FIA showed significantly more proliferation than those treated with OVA+FIA. Further, the production of IgE antibody was dramatically reduced when OVA+GS-P+FIA was used to immunize mice rather than OVA+FIA or OVA+FCA (Freund's complete adjuvant). Collectively, these results suggest that GS-P may possess adjuvant activity that potentially enhances humoral as well as cellular immune responses.