Adjuvant activities of saponins from traditional Chinese medicinal herbs

Enhanced immune responses of chickens to oral vaccination against infectious bursal disease by ginseng stem-leaf saponins

Infectious bursal disease (IBD), caused by infectious bursal disease virus (IBDV), is an immunosuppressive infectious disease of global economic importance in poultry. This study was designed to evaluate the effect of oral administration of ginseng stem-leaf saponins (GSLS) on humoral and gut mucosal immunity in chickens vaccinated with live IBDV vaccine, and furthermore, to test its protective efficacy against virulent IBDV challenge following vaccination. In experiment 1, chickens were orally administered with GSLS at 5 mg/kg of BW for 7 d, and then immunized with live IBDV vaccine via the oral route. Serum was sampled on 0, 1, 2, 3, 4, and 5 wk postvaccination for detecting antibody titers by ELISA, and intestinal tissues were collected on 0, 1, 3, and 5 wk postvaccination for measurement of IgA-positive cells and intestinal intraepithelial lymphocytes by immunohistochemical and hematoxylin-eosin staining, respectively. Result showed that antibody titers, IgA-positive cells and intestinal intraepithelial lymphocytes were significantly higher in chickens drinking GSLS than the control, suggesting an enhanced effect of GSLS on humoral and gut mucosal immune responses. In experiment 2, chickens were delivered with GSLS and then vaccinated in the same way as in experiment 1. The birds were challenged with virulent IBDV at wk 3 postvaccination. Then the birds were weighed, bled, and necropsied at d 3 postchallenge and the bursae were sampled for gross and histopathological examination. Results demonstrated that GSLS provided a better protection against virulent IBDV challenge following vaccination than the control. In conclusion, oral administration of GSLS enhances both humoral and gut mucosal immune responses to IBDV and offers a better protection against virulent IBDV challenge. Considering its immunomodulatory properties to IBDV vaccine, GSLS might be a promising oral adjuvant for vaccination against infectious diseases in poultry.

Single immunization with an inactivated vaccine protects sheep from Schmallenberg virus infection

The arthropod-borne Schmallenberg virus (SBV), family Orthobunyaviridae, emerged in Europe in 2011. SBV is associated with a mild disease in adult ruminants but fetal malformation after an infection during a critical phase of pregnancy. A number of inactivated vaccines have been developed; their efficacy after two injections was demonstrated. To make the vaccination of sheep more efficient and economic the effect of a single immunization with one of these vaccines was investigated in the present study. Five vaccinated sheep and five additional control sheep were inoculated with SBV three weeks after vaccination and the results of a competitive ELISA, a standard microneutralization test and an SBV-specific real-time RT-PCR confirmed vaccine efficacy by demonstrating complete inhibition of viral replication in immunized animals.

Effects of radix ginseng on microbial infections: a narrative review

OBJECTIVE

To summarized the antimicrobial-like effects of Radix Ginseng, which provide important information to the relevant researchers and clinicians, and will benefit the clinical treatment of infectious diseases.

METHODS

PubMed and Google were used to search for and collect scientific publications related to Radix Ginseng and microbial infections. The authors read, classified, and discussed the associated scientific results or evidences, and summarized the corresponding results.

RESULTS

In this review, recent studies on the beneficial effects of Radix Ginseng extracts on microbial and biofilm infections were reviewed. The importance and significance of Radix Ginseng's beneficial effects are discussed. Evidence for the favorable effects of Radix Ginseng extracts on viral, bacterial, fungal, and parasitic infections and the possible underlying mechanisms are summarized.

CONCLUSION

Radix Ginseng might be a promising supplemental remedy for the prevention and treatment of infectious diseases.

Ginsenoside Re as an adjuvant to enhance the immune response to the inactivated rabies virus vaccine in mice

The inactivated rabies virus vaccine (RV) is a relatively expensive vaccine, prone to failure in some cases. Ginsenoside Re (Re) is a saponin isolated from Panax ginseng, and has an adjuvant property. Here the adjuvant effect of Re to improve the immune response to the RV is evaluated in mice. ICR mice were immunized with saline, 2.50mg/kg Re, 20μl RV, 100μl RV, or 20μl of RV adjuvanted with Re (1.25, 2.50 or 5.00mg/kg). Different time points after boosting, we measured serum antibodies in blood samples and separated splenocytes to detect lymphocyte proliferation and the production of IL-4, IL-10, IL-12, and IFN-γ in vitro. We also compared immunizations containing 20μl RV and 20μl RV adjuvanted with Re (5.00mg/kg) for the expression of CD4(+) and CD8(+) T-cell subsets at different time points. Results indicated that co-administration of Re significantly enhanced serum antibody titers, increased the CD4(+):CD8(+) ratio, and enhanced both proliferation responses and IL-4, IL-10, IL-12 and IFN-γ secretions. Both Th1 and Th2 immune responses were activated. The supplementation of the Re (5.00mg/kg) to 20μl of RV significantly amplified serum antibody responses and Th1/Th2 responses inducing similar protection as did 100μl of RV. This suggests that Re could be used to reduce the dose, and therefore the cost, of the RV to achieve the same effective protection. Re merits further studies for use with vaccines of mixed Th1/Th2 immune responses.

Target network differences between western drugs and Chinese herbal ingredients in treating cardiovascular disease

Background

Western drugs have achieved great successes in CVDs treatment. However, they may lead to some side effects and drug resistance. On the other hand, more and more studies found that Traditional Chinese herbs have efficient therapeutic effects for CVDs, while their therapeutic mechanism is still not very clear. It may be a good view towards molecules, targets and network to decipher whether difference exists between anti-CVD western drugs and Chinese herbal ingredients.

Results

Anti-CVD western drugs and Chinese herbal ingredients, as well as their targets were thoroughly collected in this work. The similarities and the differences between the herbal ingredients and the western drugs were deeply explored based on three target-based perspectives including biochemical property, regulated pathway and disease network. The biological function of herbal ingredients' targets is more complex than that of the western drugs' targets. The signal transduction and immune system associated signaling pathways, apoptosis associated pathways may be the most important pathway for herbal ingredients, however the western drugs incline to regulate vascular smooth muscle contraction associated pathways. Chinese herbal ingredients prefer to regulate the downstream proteins of apoptosis associated pathway; while the western drugs incline to regulate the upstream proteins of VECC (Vascular Epidermal Cells Contraction) related pathways.

Conclusion

In summary, the characteristics identified in this study would be valuable for designing new network-based multi-target CVD drugs or vaccine adjuvants.

Effects of Korean Red Ginseng and HAART on vif Gene in 10 Long-Term Slow Progressors over 20 Years: High Frequency of Deletions and G-to-A Hypermutation

To investigate if Korean red ginseng (KRG) affects vif gene, we determined vif gene over 20 years in 10 long-term slowly progressing patients (LTSP) who were treated with KRG alone and then KRG plus HAART. We also compared these data with those of 21 control patients who did not receive KRG. Control patient group harbored only one premature stop codon (PSC) (0.9%), whereas the 10 LTSP revealed 78 defective genes (18.1%) (P < 0.001). The frequency of small in-frame deletions was found to be significantly higher in patients who received KRG alone (10.5%) than 0% in the pre-KRG or control patients (P < 0.01). Regarding HAART, vif genes containing PSCs were more frequently detected in patients receiving KRG plus HAART than patients receiving KRG alone or control patients (P < 0.01). In conclusion, our current data suggest that the high frequency of deletions and PSC in the vif gene is associated with KRG intake and HAART, respectively.

The immunological adjuvant activity of gypenosides liposome against Newcastle disease vaccine

The adjuvant activity of gypenosides liposome (GPSL) encapsulated with liposome was investigated in vitro and in vivo. In vitro, different concentrations of GPSL were added into chicken's peripheral blood lymphocytes and splenic lymphocyte. The results showed that GPSL could significantly enhance T and B lymphocytes proliferation singly or synergistically with PHA and LPS and the efficacy were superior to those of gypenosides (GPS) and blank liposome (BL) at most of concentrations. In vivo, three hundred and fifty 14-day-old chickens were assigned to 7 groups randomly and vaccinated with Newcastle disease (ND) vaccine. Simultaneously, the chickens in experimental groups were, respectively, oral administration with the GPSL at three doses, GPS and BL. The results showed that GPSL could significantly enhance lymphocyte proliferation, increase antibody titer, and promote cytokine secretion in vitro and in vivo, moreover, the adjuvant activity of GPSL was better than those of GPS and BL. These indicated that formulations of GPS and liposome can further enhance the immune response against ND vaccine compared with the adjuvant alone.

Ginseng, the 'Immunity Boost': The Effects of Panax ginseng on Immune System

Thousands of literatures have described the diverse role of ginseng in physiological processes such as cancer, neurodegenerative disorders, insulin resistance, and hypertension. In particular, ginseng has been extensively reported to maintain homeostasis of the immune system and to enhance resistance to illness or microbial attacks through the regulation of immune system. Immune system comprises of different types of cells fulfilling their own specialized functions, and each type of the immune cells is differentially influenced and may be simultaneously controlled by ginseng treatment. This review summarizes the current knowledge on the effects of ginseng on immune system. We discuss how ginseng regulates each type of immune cells including macrophages, natural killer cells, dendritic cells, T cells, and B cells. We also describe how ginseng exhibits beneficial effects on controlling inflammatory diseases and microbial infections.

Protective effect of ginsenoside-Rb2 from Korean red ginseng on the lethal infection of haemagglutinating virus of Japan in mice

Korean red ginseng has been shown to possess a variety of biological activities. However, little is known about antiviral activity of ginsenosides of Korean red ginseng. Here, we investigated the protective effect by oral administration of various ginsenosides on the lethal infection of haemagglutinating virus of Japan (HVJ) in mice. In a lethal infection model in which almost all mice infected with HVJ died within 15 days, the mice were administered orally (per os) with 1 mg/mouse of dammarane-type (ginsenoside-Rb1, -Rb2, -Rd, -Re, and -Rg2) or oleanolic acid-type (ginsenoside-Ro) ginsenosides 3, 2, and 1 d before virus infection. Ginsenoside-Rb2 showed the highest protective activity, although other dammarane-type and oleanolic acid-type ginsenosides also induced a significant protection against HVJ. However, neither the consecutive administration with a lower dosage (300 μg/mouse) nor the single administration of ginsenoside-Rb2 (1 mg/mouse) was active. In comparison of the protective activity between ginsenoside-Rb2 and its two hydrolytic products [20(S)- and 20(R)-ginsenoside-Rg3], 20(S)-ginsenoside-Rg3, but not 20(R)-ginsenoside-Rg3, elicited a partial protection against HVJ. The protective effect of ginsenoside-Rb2 and 20(S)-ginsenoside-Rg3 on HVJ infection was confirmed by the reduction of virus titers in the lungs of HVJ-infected mice. These results suggest that ginsenoside-Rb2 is the most effective among ginsenosides from red ginseng to prevent the lethal infection of HVJ, so that this ginsenoside is a promising candidate as a mucosal immunoadjuvant to enhance antiviral activity.

Frequent Genetic Defects in the HIV-1 5' LTR/gag Gene in Hemophiliacs Treated with Korean Red Ginseng: Decreased Detection of Genetic Defects by Highly Active Antiretroviral Therapy

We investigated whether Korean red ginseng (KRG) and highly active antiretroviral therapy (HAART) affect the frequency of gross deletion in 5’LTR/gag in 20 hemophiliacs. This study is a prospective study in 20 hemophiliacs who were infected with Korean subclade B of HIV-1 from two cash-paid plasma donors in 1990. Over a 13-year period, we obtained 436 amplicons of 5’LTR/gag genes by nested polymerase chain reaction using 147 peripheral blood mononuclear cells. Of the 436 amplicons, 92 (21.1%) showed gross deletion in 5’LTR/gag. Despite of a 2.3-fold higher monthly dose of KRG intake, the frequency of gross deletion in 5’LTR/gag (16.4%) was significantly decreased during HAART compared with 28.1% prior to HAART (p<0.01). Gross deletion in 5’LTR/gag was 10% more detected on KRG-therapy than prior to KRG-therapy (p<0.05). In addition, we also obtained 28 amplicons containing premature stop codon or isoleucine at initiation codon of 254 amplicons sequenced on KRG intake (7.5%) or HAART (13.6%) compared with 0% before KRG intake. These findings indicate that high frequency of gross deletion in 5’LTR/gag and genetic defects prior to HAART are significantly associated with KRG intake and the detection of gross deletion in 5’LTR/gag is decreased by HAART.

Intake of korean red ginseng extract and saponin enhances the protection conferred by vaccination with inactivated influenza a virus

Vaccination is the main strategy for preventing influenza infection. However, vaccine efficacy is influenced by several factors, including age and health status. The efficacy of the influenza vaccine is much lower (17% to 53%) in individuals over 65 yr of age compared with young adults (70% to 90%). Therefore, increasing vaccine efficacy remains a challenge for the influenza vaccine field. In this study, we investigated the impact of supplementing vaccination with the dietary intake of Korean red ginseng (RG) extract and RG saponin. Mice were immunized two times intranasally with inactivated influenza A (H1N1) virus. Mice received RG extract or RG saponin orally for 14 d prior to the primary immunization. After the primary immunization, mice continued to receive RG extract or RG saponin until the secondary immunization. Mice vaccinated in combination with dietary intake of RG extract and RG saponin showed elevated serum anti-influenza A virus IgG titers and improved survival rates in lethal influenza A virus infection: 56% and 63% of mice receiving RG extract or RG saponin survived, respectively, while 38% of mice that only received the vaccine survived. Moreover, mice receiving RG extract supplementation recovered their body weight more quickly than those not receiving RG extract supplementation. We propose that the dietary intake of RG extract and RG saponin enhances the vaccine-induced immune response and aids in providing protection against influenza virus infection.

Immunobiologic and antiinflammatory properties of a bark extract from Ampelozizyphus amazonicus Ducke

Ampelozizyphus amazonicus is used in the treatment and prevention of malaria. The effect of an aqueous extract from this plant (SART) on the immune response was investigated by measuring immunoglobulin production induced by immunization with the antigen TNP-Ficoll in Plasmodium chabaudi-infected mice. SART treatment increased antigen-specific IgM and IgG levels in TNP-Ficoll-immunized mice. The B cell response during malarial infection was also modified by SART. There was an increase in total serum IgM and IgG and a decrease in the percentage of splenic plasma cells (CD138+ cells) in P. chabaudi-infected, SART-treated animals. SART (1, 3 or 10 mg/kg, p.o.) and the reference drug dexamethasone (5 mg/kg) were also tested in carrageenan-induced leukocyte migration to the subcutaneous air pouch (SAP). All SART doses significantly reduced leukocyte migration into the SAP. The protein concentration resulting from extravasation into the peritoneum was also significantly reduced. Our data indicate that SART possesses immunomodulatory properties, inducing an in vivo modification of the B lymphocyte response and anti-inflammatory properties, which are partly due to a reduction in cell migration and are most likely due to an inhibition of the production of inflammatory mediators. Preliminary HPLC-ESI-MS/MS analysis of SART shows a complex saponin profile with deprotonated molecule [M-H]⁻ ions in the range of m/z 800–1000.

Developing Phytocompounds from Medicinal Plants as Immunomodulators

Imbalance or malfunction of the immune systems is associated with a range of chronic diseases including autoimmune diseases, allergies, cancers and others. Various innate and adaptive immune cells that are integrated in this complex networking system may represent promising targets for developing immunotherapeutics for treating specific immune diseases. A spectrum of phytochemicals have been isolated, characterized and modified for development and use as prevention or treatment of human diseases. Many cytotoxic drugs and antibiotics have been developed from phytocompounds, but the application of traditional or new medicinal plants for use as immunomodulators in treating immune diseases is still relatively limited. In this review, a selected group of medicinal herbs, their derived crude or fractionated phytoextracts and the specific phytochemicals/phytocompounds isolated from them, as well as categorized phytocompound groups with specific chemical structures are discussed in terms of their immunomodulatory bioactivities. We also assess their potential for future development as immunomodulatory or inflammation-regulatory therapeutics or agents. New experimental approaches for evaluating the immunomodulatory activities of candidate phytomedicines are also discussed.

Attenuation of cysteamine-induced duodenal ulcer with Cochinchina momordica seed extract through inhibiting cytoplasmic phospholipase A2/5-lipoxygenase and activating γ-glutamylcysteine synthetase

BACKGROUND AND AIM

Cysteamine is a reducing aminothiol used for inducing duodenal ulcer through mechanisms of oxidative stress related to thiol-derived H(2)O(2) reaction. Cochinchina momordica saponins have been suggested to be protective against various gastric diseases based on their cytoprotective and anti-inflammatory mechanisms. This study was aimed to document the preventive effects of Cochinchina momordica seed extract against cysteamine-induced duodenal ulcer as well as the elucidation of its pharmacological mechanisms.

METHODS

Cochinchina momordica seed extract (50, 100, 200 mg/kg) was administrated intragastrically before cysteamine administration, after which the incidence of the duodenal ulcer, ulcer size, serum gastrin level, and the ratio of reduced glutathione (GSH)/oxidized glutathione disulfide (GSSG) as well as biochemical and molecular measurements of cytoplasmic phospholipase A(2) (cPLA(2)), cyclooxygenase-2 (COX-2), 5-lipoxygenase and the expression of proinflammatory genes including IL-1β, IL-6, COX-2 were measured in rat model. Additional experiments of electron spin resonance measurement and the changes of glutathione were performed.

RESULTS

Cochinchina momordica seed extract effectively prevented cysteamine-induced duodenal ulcer in a dose-dependent manner as reflected with significant decreases in either duodenal ulcerogenesis or perforation accompanied with significantly decreased in serum gastrin in addition to inflammatory mediators including cPLA(2), COX-2, and 5-lipoxygenase. Cochinchina momordica seed extract induced the expression of γ-glutamylcysteine synthetase (γ-GCS)-related glutathione synthesis as well as significantly reduced the expression of cPLA(2). Cochinchina momordica seed extract preserved reduced glutathione through increased expressions of γ-GCS.

CONCLUSION

Cochinchina momordica seed extracts exerted significantly protective effect against cysteamine-induced duodenal ulcer by either cPLA2 inhibition or glutathione preservation.

Ginsenosides Rg1 and Re act as adjuvant via TLR4 signaling pathway

Previous studies have demonstrated that ginsenosides Rg1 and Re extracted from the root of Panax ginseng C.A. Meyer have adjuvant properties. However, the molecular mechanisms behind their adjuvant activities remain unclear. In the present study, we first investigated the adjuvant effect of Rg1 and Re on the immune responses to a model antigen ovalbumin (OVA) in C3H/HeB mice as well as in C3H/HeJ mice carrying a defective toll-like receptor-4 (TLR4) gene, and then evaluated Rg1 and Re for their stimulation of phosphorylation of nuclear factor-kappa B (NF-κB) p65 in the macrophages from above two different strains of mice. In addition, Rg1 and Re were also evaluated for their induction of NF-κB in RAW-Blue™ cells. The results showed that Rg1 and Re had adjuvant activities in stimulating IgG, splenocyte proliferation, and mRNA expression of cytokines IL-4, IL-10, IL-12 and IFN-γ as well as transcription factors GATA-3 and T-bet by splenocytes in C3H/HeB mice but not in C3H/HeJ mice. Rg1 and Re induced phosphorylation of NF-κB p65 at Ser536 in macrophages from C3H/HeB mice but not from C3H/HeJ mice. Both Rg1 and Re induced expression of NF-κB in RAW-Blue™ cells. These results suggested that TLR4 signaling pathway is involved in the adjuvant activities of Rg1 and Re. Nevertheless, pretreatment with anti-TLR4 antibody suppressed the Re- but not Rg1-induced expression of NF-κB, indicating that Rg1 may trigger both extracellular and intracellular TLR4 by passing through the cell membrane while Re only activate extracellular TLR4 as it fails to enter inside of the cells to stimulate intracellular TLR4.

Immunoadjuvant activity, toxicity assays, and determination by UPLC/Q-TOF-MS of triterpenic saponins from Chenopodium quinoa seeds

The adjuvant activity of Chenopodium quinoa (quinoa) saponins on the humoral and cellular immune responses of mice subcutaneously immunized with ovalbumin (OVA) was evaluated. Two quinoa saponin fractions were obtained, FQ70 and FQ90, and 10 saponins were determined by UPLC/Q-TOF-MS. Mice were immunized subcutaneously with OVA alone or adjuvanted with Quil A (adjuvant control), FQ70, or FQ90. FQ70 and FQ90 significantly enhanced the amount of anti-OVA-specific antibodies in serum (IgG, IgG1, and IgG2b) in immunized mice. The adjuvant effect of FQ70 was significantly greater than that of FQ90. However, delayed type hypersensitivity responses were higher in mice immunized with OVA adjuvanted with FQ90 than mice treated with FQ70. Concanavalin A (Con A)-, lipopolysaccharide-, and OVA-stimulated splenocyte proliferation were measured, and FQ90 significantly enhanced the Con A-induced splenocyte proliferation. The results suggested that the two quinoa saponin fractions enhanced significantly the production of humoral and cellular immune responses to OVA in mice.

Phytol-derived novel isoprenoid immunostimulants

This review describes the adjuvanticity of novel diterpenoids (synthetic phytol derivatives) compared to some commercially available adjuvants. The efficacy of the phytol-derived immunostimulants was evaluated in terms of their ability to activate innate immunity, amplify various antigen-specific immune responses, and engender immunological memory with no discernible adverse effects in both competent and immune-deficient mice. The profile that emerges out of these studies reveals that the phytol derivatives are excellent immunostimulants, superior to a number of commercial adjuvants in terms of long-term memory induction and activation of both innate and acquired immunity. Additionally, the phytol-derived compounds have no cumulative inflammatory or toxic effects even in immuno-compromised mice.

Phenotypic and functional maturation of murine dendritic cells (DCs) induced by purified Glycyrrhizin (GL)

The aim of this study is to investigate phenotypic and functional modulation of murine dendritic cells (DCs) with use of purified Glycyrrhizin (GL). These impacts of GL on DCs both from bone marrow derived DCs and established DC cell 2.4 were assessed with conventional scanning electron microscopy (SEM), flow cytometry (FCM), transmission electron microscopy (TEM), cytochemistry assay, FITC-dextran, bio-assay and enzyme linked immunosorbent assay (ELISA). We found that the purified GL induced phenotypic maturation as evidenced by increased expression of CD86, CD40, CD80, CD83 and major histocompatibility complex II (MHC II). The functional tests showed the activity of acidic phosphatase (ACP) inside the DCs2.4 cells were down- regulated after treatment with GL (which occurs when phagocytosis of DCs2.4 cells were decreased). Finally, we proved that GL increased the production of IL-12, IL-10 and decreased the production of tumor necrosis factor alpha (TNF-α). These data indicated that GL could promote maturation of DCs and this adjuvant-like activity may have potential therapeutic value. It is therefore concluded that GL could exert positive modulation on murine DCs.

Enhancement of humoral immune responses to inactivated Newcastle disease and avian influenza vaccines by oral administration of ginseng stem-and-leaf saponins in chickens

Newcastle disease (ND) and avian influenza (AI) are common in the poultry industry. The objective of this study was to evaluate the effect of oral administration of ginseng stem-and-leaf saponins (GSLS) on the humoral immune responses of chickens to inactivated ND and AI vaccines. In experiment 1, oral administration of GSLS at a dose of 5 mg/kg of BW for 7 d on the immune response in chickens intramuscularly injected with inactivated ND vaccine was evaluated. Results showed that GSLS significantly increased the antibody level against ND in the serum of chickens. In experiment 2, the same regimen of GSLS was administered to chickens inoculated with inactivated AI vaccines, and an enhanced serum antibody response to AI vaccination was also observed. Considering the safety of GSLS, because no adverse effect was found throughout the experiments, GSLS may be a promising oral adjuvant to improve immunization in poultry.

Leukocyte-stimulating effect and phytochemical screening of Trichilia hirta extracts

Trichilia hirta (Family Meliaceae) is a tree traditionally used in the folk medicine of Cuba to treat asthma, cancer, and ulcers. The objective of this study was to determine the phytochemical composition of ethanol extracts obtained from leaves, roots, and stem bark and to evaluate the leukocyte-stimulating effect of T. hirta root extracts on BALB/c mice. The chemical composition of the extracts was determined by phytochemical screening. Saponins, tannins, flavonoids, and coumarins were detected in extracts of T. hirta. The leukocyte-stimulating effect was evaluated by oral application of ethanol extracts (81.8 and 976 mg/kg) in BALB/c mice for 7 days. The application of 976 mg of extract/kg increased the total leukocyte count up to 15-33%; this effect was significant for neutrophil counts compared with control animals (P<.05). In addition, a dose of 82 mg/kg significantly increased total leukocytes at day 4 of the study (P<.05). The results indicated that T. hirta extracts contain phytochemicals reported as immunostimulants. The administration of these extracts to BALB/c mice indicated that ethanol extract could exhibit leukocyte-stimulating properties and makes it a promising alternative for the development of an immunoprotective agent.

Plant immunostimulants--scientific paradigm or myth?

In traditional medicine, numerous plant preparations are used to treat inflammation both topically and systemically. Several anti-inflammatory plant extracts and a few natural product-based monosubstances have even found their way into the clinic. Unfortunately, a number of plant secondary metabolites have been shown to trigger detrimental pro-allergic immune reactions and are therefore considered to be toxic. In the phytotherapy research literature, numerous plants are also claimed to exert immunostimulatory effects. However, while the concepts of plant-derived anti-inflammatory agents and allergens are well established, the widespread notion of immunostimulatory plant natural products and their potential therapeutic use is rather obscure, often with the idea that the product is some sort of "tonic" for the immune system without actually specifying the mechanisms. In this commentary it is argued that the paradigm of oral plant immunostimulants lacks clinical evidence and may therefore be a myth, which has originated primarily from in vitro studies with plant extracts. The fact that no conclusive data on orally administered immunostimulants can be found in the scientific literature inevitably prompts us to challenge this paradigm.

Effects of Panax ginseng on tumor necrosis factor-α-mediated inflammation: a mini-review

Panax ginseng is one of the most commonly used Chinese medicines in China, Asia and Western countries. The beneficial effects of ginseng have been attributed to the biological activities of its constituents, the ginsenosides. In this review, we summarize recent publications on the anti-inflammatory effects of ginseng extracts and ginsenosides on cellular responses triggered by different inducers including endotoxin, tumor necrosis factor-alpha (TNF-α), interferon-gamma and other stimuli. Proinflammatory cytokines, chemokines, adhesion molecules and mediators of inflammation including inducible nitric oxide synthase, cyclooxygenase-2 and nitric oxide orchestrate the inflammatory response. Ginseng extracts and ginsenosides including Rb₁, Rd, Rg₁, Rg₃, Rh₁, Rh₂, Rh₃ and Rp₁ have been reported to have anti-inflammatory properties in different studies related to inflammation. Ginsenosides inhibit different inducers-activated signaling protein kinases and transcription factor nuclear factor-kappaB leading to decreases in the production of cytokines and mediators of inflammation. The therapeutic potential of ginseng on TNF-α-mediated inflammatory diseases is also discussed. Taken together, this summary provides evidences for the anti-inflammatory effects of ginseng extracts and ginsenosides as well as the underlying mechanisms of their effects on inflammatory diseases.

Modulation of phenotypic and functional maturation of murine dendritic cells (DCs) by purified Achyranthes bidentata polysaccharide (ABP)

There are a large number of interactions at molecular and cellular levels between the plant polysaccharides and immune system. Plant polysaccharides present an interesting effects as immunomodulators, particularly in the induction of the cells both in innate and adaptive immune systems. Activation of DCs could improve antitumoral responses usually diminished in cancer patients, and natural adjuvants provide a possibility of inducing this activation. ABP is a purified polysaccharide isolated from Achyranthes bidentata, a traditional Chinese medicine (TCM). The aim of this study is to investigate modulation of phenotypic and functional maturation of murine DCs by ABP. Both phenotypic and functional activities were assessed with use of conventional scanning electronic microscopy (SEM) for the morphology of the DC, transmitted electron microscopy (TEM) for intracellular lysosomes inside the DC, cellular immunohistochemistry for phagocytosis by the DCs, flow cytometry (FCM) for the changes in key surface molecules, bio-assay for the activity of acidic phosphatases (ACP), and ELISA for the production of pro-inflammatory cytokine IL-12. In fact, we found that purified ABP induced phenotypic maturation revealed by increased expression of CD86, CD40, and MHC II. Functional experiments showed the down-regulation of ACP inside DCs (which occurs when phagocytosis of DCs is decreased, and antigen presentation increased with maturation). Finally, ABP increased the production of IL-12. These data reveal that ABP promotes effective activation of murine DCs. This adjuvant-like activity may have therapeutic applications in clinical settings where immune responses need boosting. It is therefore concluded that ABP can exert positive modulation to murine DCs.

Intramammary inoculation of Panax ginseng extract in cows at drying off enhances early mammary involution

This study was designed to evaluate the effects of a single intramammary infusion of Panax ginseng extract on cell proliferation and death mechanism in bovine mammary gland during early involution. Eight mammary quarters from six non-pregnant cows in late lactation were infused with 10 ml of ginseng solution (3 mg/ml), six quarters were treated with 10 ml of placebo (vehicle alone) and six quarters were maintained as uninoculated controls. Milking was interrupted after infusion. Animals included in the three groups were slaughtered 7 d after inoculation and samples for histological analysis were taken. Morphometric analysis showed a significant increase in percentages of mammary tissue area occupied by stroma in ginseng-treated quarters compared with controls. A significant increase of immunostained area for bax protein and active caspase-3 was observed in ginseng-treated quarters compared with controls, whereas no differences were observed for bcl-2 immunostaining. Expression of bax mRNA was significantly higher in ginseng-treated quarters than in controls. The bax/bcl-2 ratio indicated a significant predominance of bax over bcl-2 mRNA expression in ginseng-treated quarters compared with controls. The rise of epithelial and stromal cell apoptosis in situ by TUNEL was more marked in quarters treated with ginseng than in controls. Ginseng inoculation had no effect on the number of epithelial and stromal proliferating cells labelled with Ki-67 antibody. Ratio of apoptotic to proliferating cells was higher in quarters treated with ginseng compared with controls, indicating a net loss of cells in parenchymal components. Also, the intramammary inoculation of ginseng extract at drying off increased the rate of mammary cell apoptosis without inhibiting cell proliferation. Taken together, these changes are indicative of mammary regression enhancement during early involution.

Preparation and in vivo study of dry powder microspheres for nasal immunization

The immunoadjuvant potential of alginate microspheres as delivery system, and cross-linked dextran microspheres (CDM) as absorption enhancer and excipient for powder of alginate microspheres, were evaluated. Alginate microspheres were prepared by emulsification method. Microspheres encapsulated with tetanus toxoid (TT) or Quillaja saponin (QS) were nasally administered to rabbits, three times in 2 weeks interval and serum IgG and nasal lavage sIgA titers were determined by ELISA. The mean diameter of microspheres was about 1.5 mum. Release of TT and QS was 13.1 +/- 1.4% and 31.8 +/- 4.3% after 4 h. The serum IgG titer induced with (TT)(ALG) microspheres was higher than TT solution (P<0.001). Addition of QS or CDM adjuvant, in separate, to (TT)(ALG) microspheres could not significantly increase the immune responses (P>0.05), but the highest systemic IgG titers induced with (TT+QS)(ALG)+CDM (P<0.01). The sIgA titer induced with (TT)(ALG) microspheres was higher than TT solution (P<0.05). The highest mucosal sIgA titers were seen in animals immunized with (TT)(ALG)+CDM (P<0.05). Co-encapsulation of QS and TT in microspheres did not increase the sIgA titers. When CDM was added to alginate microspheres encapsulated with TT or TT+QS, the highest mucosal and systemic responses were observed.