The adjuvant effects of high-molecule-weight polysaccharides purified from Antrodia cinnamomea on dendritic cell function and DNA vaccines

The biological activity of the edible basidiomycete Antrodia cinnamomea (AC) has been studied extensively. Many effects, such as anti-cancer, anti-inflammatory, and antioxidant activities, have been reported from either crude extracts or compounds isolated from AC. However, research addressing the function of AC in enhancing immunity is rare. The aim of the present study is to investigate the active components and the mechanism involved in the immunostimulatory effect of AC. We found that polysaccharides (PS) in the water extract of AC played a major role in dendritic cell (DC) activation, which is a critical leukocyte in initiating immune responses. We further size purified and identified that the high-molecular weight PS fraction (greater than 100 kDa) exhibited the activating effect. The AC high-molecular weight PSs (AC hmwPSs) promoted pro-inflammatory cytokine production by DCs and the maturation of DCs. In addition, DC-induced antigen-specific T cell activation and Th1 differentiation were increased by AC hmwPSs. In studying the molecular mechanism, we confirmed the activation of the MAPK and NF-κB pathways in DCs after AC hmwPSs treatment. Furthermore, we demonstrated that TLR2 and TLR4 are required for the stimulatory activity of AC hmwPSs on DCs. In a mouse tumor model, we demonstrated that AC hmwPSs enhanced the anti-tumor efficacy of the HER-2/neu DNA vaccine by facilitating specific Th1 responses. Thus, we conclude that hmwPSs are the major components of AC that stimulate DCs via the TLR2/TLR4 and NF-κB/MAPK signaling pathways. The AC hmwPSs have potential to be applied as adjuvants.

Transfection efficiency and internalization of the gene carrier prepared from a triple-helical β-glucan and polydeoxyadenylic acid in macrophage RAW264.7 cells

The stability and gene transfection efficiency of poly(dA)–s-LNT complexes strongly depend on the base length of poly(dA) in the target DNA sequence.

Isolation and antitumor efficacy evaluation of a polysaccharide from Nostoc commune Vauch

A polysaccharide from Nostoc commune Vauch. (NVPS) was characterized and its antitumor efficacy was elucidated.

A high throughput colorimetric assay of β-1,3-D-glucans by Congo red dye

Mushroom strains contain complex nutritional biomolecules with a wide spectrum of therapeutic and prophylactic properties. Among these compounds, β-d-glucans play an important role in immuno-modulating and anti-tumor activities. The present work involves a novel colorimetric assay method for β-1,3-d-glucans with a triple helix tertiary structure by using Congo red. The specific interaction that occurs between Congo red and β-1,3-d-glucan was detected by bathochromic shift from 488 to 516 nm (>20 nm) in UV-Vis spectrophotometer. A micro- and high throughput method based on a 96-well microtiter plate was devised which presents several advantages over the published methods since it requires only 1.51 μg of polysaccharides in samples, greater sensitivity, speed, assay of many samples and very cheap. β-D-Glucans of several mushrooms (i.e., Coriolus versicolor, Ganoderma lucidum, Pleurotus ostreatus, Ganoderma carnosum, Hericium erinaceus, Lentinula edodes, Inonotus obliquus, Auricularia auricular, Polyporus umbellatus, Cordyseps sinensis, Agaricus blazei, Poria cocos) were isolated by using a sequence of several extractions with cold and boiling water, acidic and alkaline conditions and quantified by this microtiter plate method. FTIR spectroscopy was used to study the structural features of β-1,3-D-glucans in these mushroom samples as well as the specific interaction of these polysaccharides with Congo red. The effect of NaOH on triple helix conformation of β-1,3-D-glucans was investigated in several mushroom species.

The TLR2 agonist in polysaccharide-K is a structurally distinct lipid which acts synergistically with the protein-bound β-glucan

Protein-bound polysaccharide-K (Krestin; PSK) is a hot-water extract of Trametes versicolor with immune stimulatory activity. It has been used for the past 30 years and has demonstrated anti-tumor efficacy in multiple types of cancer. The ability of PSK to activate dendritic cells and T cells is dependent on its ability to stimulate Toll-like receptor 2 (TLR2), yet it remains unknown which structural component within PSK activates TLR2. The purpose of this study was to identify the TLR2 agonist within PSK and understand its role in the overall mechanism of PSK's immunogenic activity. TLR2 activity was eliminated by treatment with lipoprotein lipase but not by trypsin or lyticase. Rapid centrifugation of PSK can separate the fraction with TLR2 agonist activity from the soluble β-glucan fraction. To study the potential interaction between the β-glucan component and the lipid component, we labeled the soluble β-glucan with fluorescein. Uptake of the labeled β-glucan by J774A macrophages and JAWSII dendritic cells was inhibited by anti-Dectin-1 antibody but not by anti-TLR2 antibody, confirming that Dectin-1 is the receptor for β-glucan. Interestingly, pre-treatment of JAWSII cells with the TLR2-active lipid fraction significantly enhanced the uptake of the soluble β-glucan, indicating the synergy between the TLR2 agonist component and the β-glucan component. Altogether, these results present evidence that PSK has two active components-the well-characterized protein-bound β-glucan and a previously unreported lipid-which work synergistically via the Dectin-1 and TLR2 receptors.

Lentinan reduces tumor progression by enhancing gemcitabine chemotherapy in urothelial bladder cancer

It has been shown that chemotherapy has limited antitumor activity against advanced urothelial bladder cancer (UBC). Consequently, there is an urgent need to develop effective therapeutic methods for patients with advanced UBC. In the present study, the inhibitory effects of lentinan alone, gemcitabine alone, or lentinan combined with gemcitabine on the proliferation of the UBC cell line, T24, were investigated. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay, annexin V fluorescein isothiocyanate/propidium iodide staining, and flow cytometry were used to determine the proliferation and apoptosis of T24 cells in each treatment group. Survival-related protein expression was analyzed by western blotting. Increased concentrations of lentinan, or lentinan combined with gemcitabine, positively correlated with decreased T24 cell proliferation. Lentinan combined with gemcitabine chemotherapy significantly inhibited UBC cell proliferation. Gemcitabine has the ability to induce T24 cell apoptosis, and this effect is enhanced when it is combined with lentinan.

Possible mechanisms of action of mushroom-derived glucans on inflammatory bowel disease and associated cancer

Since ancient times, medicinal mushrooms have been traditionally used as a health food or supplement for the prevention and cure of a range of health-statuses or diseases, such as overt inflammation, atherosclerosis, cancer, hypertension, diabetes and others. We concentrate in this review on the effect and putative mechanism of action of glucans harvested from fungi on inflammatory bowel disease (IBD) and colitis associated cancer. Many scientists including our own group have examined the immunomodulating effect of isolated polysaccharides-glucans in general and specifically in inflammation associated with cancer. In this manuscript we reviewed the sources, the chemical composition and medicinal properties of polysaccharides extracted from edible mushrooms. In addition we brought insights into their putative mechanisms of action behind each health-promoting activity of these interesting biomolecules. The preventive and therapeutic effects of the medicinal mushrooms and their components have been well documented in mouse and rat model systems and in cancer cell lines being the most striking effects reported to their anti-inflammatory and antitumor effect. Their anticancer effects were demonstrated mainly in in vitro and in vivo experimental systems but a very limited number of studies have been conducted in human populations. We can summarize that oral consumption of several mushrooms glucans is an efficient treatment to prevent colitis-associated dysplasias through modulation of mucosal inflammation and cell proliferation. Identifying new food-derived isolates and understanding their mechanisms of action are the main challenges in using mushrooms glucans for therapeutic purposes in the field of IBD and associated cancer. Only an in-depth understanding of the mechanism of action and cross-talk between the inflammatory cell, epithelial cell and fungi derived glucans on which we have a based structural knowledge will lead to well designed intervention clinical human studies to test the efficacy of these molecules on intestinal inflammation and colitis associated cancer.

A polysaccharide from Ganoderma atrum inhibits tumor growth by induction of apoptosis and activation of immune response in CT26-bearing mice

Ganoderma atrum is one species of edible and pharmaceutical mushroom with various biological activities. Recently, a novel polysaccharide, PSG-1, was purified from G. atrum. The antitumor activity and its mechanism of action were studied. In vitro, PSG-1 has little effect on inhibiting proliferation of CT26 tumor cells. However, the tumor size was significantly decreased in PSG-1-treated mice. The results showed that PSG-1 induced apoptosis in CT26 cells. Moreover, the intracellular cyclic AMP (cAMP) level and protein kinase A (PKA) activity were markedly increased in PSG-1-treated mice. In contrast, the contents of cyclic GMP and DAG and the PKC activity were decreased. Similarly, the expression of PKA protein was upregulated, while PKC protein expression in PSG-1-treated group was lowered. Additionally, PSG-1 increased the immune organ index and serum biochemistry parameter. In general, PSG-1 enhances the antitumor immune response, induces apoptosis in CT26-bearing mice, and could be a safe and effective adjuvant for tumor therapy or functional food.

Effects of drying methods on physicochemical and immunomodulatory properties of polysaccharide-protein complexes from litchi pulp

Dried litchi pulp has been used in traditional remedies in China for many years to treat various diseases, and the therapeutic activity has been, at least partly, attributed to the presence of bioactive polysaccharides. Polysaccharide-protein complexes from vacuum freeze-(VF), vacuum microwave-(VM) and heat pump (HP) dried litchi pulp, which were coded as LP-VF, LP-VM and LP-HP, were comparatively studied on the physicochemical and immunomodulatory properties. LP-HP had a predominance of galactose, while glucose was the major sugar component in LP-VF and LP-VM. Compared with LP-VF and LP-VM, LP-HP contained more aspartate and glutamic in binding protein. LP-HP also exhibited a stronger stimulatory effect on splenocyte proliferation at 200 μg/mL and triggered higher NO, TNF-α and IL-6 secretion from RAW264.7 macrophages. Different drying methods caused the difference in physicochemical properties of polysaccharide-protein complexes from dried litchi pulp, which resulted in significantly different immunomodulatory activity. HP drying appears to be the best method for preparing litchi pulp to improve its immunomodulatory properties.

Water extract from Pleurotus pulmonarius with antioxidant activity exerts in vivo chemoprophylaxis and chemosensitization for liver cancer

Chemoprophylaxis and chemosensitization are promising strategies to combat human cancers. Natural antioxidant agents show great promise in cancer therapy, and the use of edible mushrooms against cancer is receiving more interest globally. In this study, the radical scavenging activities including diphenyl-1-picrylhydrazyl, superoxide anion radical, hydroxyl radical, and hydrogen peroxide were compared among hot water extracts from 3 edible mushrooms, among which Pleurotus pulmonarius (Pp) possessed the highest antioxidant potential. Oral administration of Pp 2 wk in advance could markedly inhibit the incidence and size of tumor (Huh7 liver cancer cells) with an inhibition rate of 93.1% in nude mice. No obvious side effect was observed in the Pp-treated mice as indicated by their body weight and histological analysis of major organs. The cancer prevention by Pp treatment might be explained by the inhibition of cancer cell proliferation indicated by reduction of ki-67 staining and the inactivation of phosphoinositide 3-kinase (PI3K)/AKT signaling pathway in the Pp-treated mice. Furthermore, a significant synergistic effect was observed when the mice were treated with a combination of low dose of cisplatin and Pp. Taken together, these results suggest the potential application of Pp as an adjuvant in the chemotherapy of liver cancer.

Influence of culture medium growth variables on Ganoderma lucidum exopolysaccharides structural features

In this work the effect of carbon and nitrogen levels and initial pH of the wheat extract culture medium of submerged culture of Ganoderma lucidum on the amount, purity and structural features of exopolysaccharides (EPS) were studied. A low peptone level (1.65 g L(-1)) favored mycelium biomass, EPS purity, but a higher supply of peptone (4.80 g L(-1)) is needed for maximum EPS production. The carbohydrate composition of the EPS and structural features also changed significantly according to the different growing conditions, being observed significant differences in the (1 → 3)/(1 → 4)-Glcp ratio and also on the branching degree of EPS. As the biological activities of EPS are highly dependent on the polysaccharide structural features, this variability can have implications on the EPS biological activities, but can also be used advantageously to produce tailor made polysaccharides with specific applications.

Structurally characterized arabinogalactan from Anoectochilus formosanus as an immuno-modulator against CT26 colon cancer in BALB/c mice

In this study, the innate immuno-modulatory effects and anti-cancer action of arabinogalactan (AG), a derivative of a well-known orchid, Anoectochilus formosanus, were investigated. The innate immuno-modulatory effects of AG were determined in vitro using RAW 264.7 cells for microarray analysis, and in vivo using BALB/c mice administrated with AG at 5 and 15 mg/kg intra-peritoneally for 3 weeks. The anti-cancer activity of AG was evaluated by CT26 colon cancer-bearing BALB/c mice. The microarray analysis was performed to evaluate the innate immunity and demonstrated that AG significantly induced the expression of cytokines, chemokines, and co-stimulatory receptors, such as IL-1α, CXCL2, and CD69. An intraperitoneal injection of AG in mice increased the spleen weight, but not the body weight. The treatment of mitogen, LPS significantly stimulated splenocyte proliferation in AG treated groups. The AG treatment also promoted splenocyte cytotoxicity against YAC-1 cells and increased the percentage of CD3(+)CD8(+) cytotoxic T cells in innate immunity test. Our experiments revealed that AG significantly decreased both tumour size and tumour weight. Besides, AG increased the percentage of DC, CD3(+)CD8(+) T cells, CD49b(+)CD3(-) NK cells among splenocytes, and cytotoxicity activity in tumour-bearing mice. In addition, the immunohistochemistry of the tumour demonstrated that the AG treatments increased the tumour-filtrating NK and cytotoxic T-cell. These results demonstrated that AG, a polysaccharide derived from a plant source, has potent innate immuno-modulatory and anti-cancer activity. AG may therefore be used for cancer immunotherapy.

Dietary mushroom intake may reduce the risk of breast cancer: evidence from a meta-analysis of observational studies

Epidemiological studies have investigated the potential anticancer effects of mushroom intake. This review aims to clarify the evidence on the association of dietary mushroom intake with breast cancer risk and to quantify its dose-response relationship. Relevant studies were identified by a search of PubMed, Web of Science and Google Scholar up to December 31, 2013. Observational studies with relative risks (RRs) or hazard ratios (HRs) or odd ratios (ORs) and 95% confidence intervals (CIs) of breast cancer for three or more categories of mushroom intake were eligible. The quality of included studies was assessed by using Newcastle-Ottawa Scale. A dose-response meta-analysis was performed by utilizing generalized least squares trend estimation. Eight case-control studies and two cohort studies with a total of 6890 cases were ultimately included. For dose-response analysis, there was no evidence of non-linear association between mushroom consumption and breast cancer risk (P = 0.337) and a 1 g/d increment in mushroom intake conferred an RR of 0.97 (95% CI: 0.96–0.98) for breast cancer risk, with moderate heterogeneity (I² = 56.3%, P = 0.015). Besides, available menopause data extracted from included studies were used to evaluate the influence of menopausal statues. The summary RRs of mushroom consumption on breast cancer were 0.96 (95% CI: 0.91–1.00) for premenopausal women and 0.94 (95% CI: 0.91–0.97) for postmenopausal women, respectively. Our findings demonstrated that mushroom intake may be inversely associated with risk of breast cancer, which need to be confirmed with large-scale prospective studies further.

Hericium erinaceus (Yamabushitake): a unique resource for developing functional foods and medicines

This article provides valuable scientific information for Hericium erinaceus and shows its potential for the development of new functional foods and drugs.

Structure and inducing tumor cell apoptosis activity of polysaccharides isolated from Lentinus edodes

In this study, five novel polysaccharides SLNT1, SLNT2, JLNT1, JLNT2, and JLNT3 were isolated from the fruit body of Lentinus edodes. Chemical and physical analyses showed that the five polysaccharides consist of glucose with the structure of β-(1→3)-d-glucose main chains and β-(1→6)-d-glucose side chains. Moreover, all of them had triple-helical conformation and different molecular weight distributions. Animal studies further demonstrated that the antitumor effects were remarkably improved by SLNT1 and JLNT1 treatments with the inhibitory rates of 65.41% and 61.07% in H22-bearing mice, respectively. Additionally, both of them significantly increased the levels of serum IL-2 and TNF-α production and induced the tumor cell apoptosis. Taken together, our findings revealed that the involved antitumor mechanisms possibly in part were mediated not only by enhancing the immunity but also by directly killing the tumor and the induction of tumor cell apoptosis in H22-bearing mice.

Mushroom immunomodulators: unique molecules with unlimited applications

For centuries, mushrooms have been used as food and medicine in different cultures. More recently, many bioactive compounds have been isolated from different types of mushrooms. Among these, immunomodulators have gained much interest based on the increasing growth of the immunotherapy sector. Mushroom immunomodulators are classified under four categories based on their chemical nature as: lectins, terpenoids, proteins, and polysaccharides. These compounds are produced naturally in mushrooms cultivated in greenhouses. For effective industrial production, cultivation is carried out in submerged culture to increase the bioactive compound yield, decrease the production time, and reduce the cost of downstream processing. This review provides a comprehensive overview on mushroom immunomodulators in terms of chemistry, industrial production, and applications in medical and nonmedical sectors.

Immunostimulatory properties and antitumor activities of glucans (Review)

New foods and natural biological modulators have recently become of scientific interest in the investigation of the value of traditional medical therapeutics. Glucans have an important part in this renewed interest. These fungal wall components are claimed to be useful for various medical purposes and they are obtained from medicinal mushrooms commonly used in traditional Oriental medicine. The immunotherapeutic properties of fungi extracts have been reported, including the enhancement of anticancer immunity responses. These properties are principally related to the stimulation of cells of the innate immune system. The discovery of specific receptors for glucans on dendritic cells (dectin-1), as well as interactions with other receptors, mainly expressed by innate immune cells (e.g., Toll-like receptors, complement receptor-3), have raised new attention toward these products as suitable therapeutic agents. We briefly review the characteristics of the glucans from mycelial walls as modulators of the immunity and their possible use as antitumor treatments.

Immunomodulatory activity of polysaccharides isolated from Alchornea cordifolia

ETHNOPHARMACOLOGICAL RELEVANCE

Extracts of leaves from different species of the genus Alchornea have been used for centuries to treat a variety of medicinal problems in tropical Africa. However, little is known about the high-molecular weight active components conferring therapeutic properties to these extracts.

OBJECTIVE

The aim of this study was to evaluate the immunomodulatory activity of polysaccharides isolated from the leaves of Alchornea cordifolia.

MATERIALS AND METHODS

Water-soluble polysaccharides from leaves of Alchornea cordifolia were extracted and fractionated by DEAE-cellulose, Diaion HP-20, and size-exclusion chromatography. Molecular weight, sugar analysis, and other physical and chemical characterization of the fractions were performed. Immunomodulatory activity of the polysaccharide fractions was evaluated by determining their ability to induce monocyte/macrophage nitric oxide (NO) and cytokine production. Activation of mitogen activated protein kinases (MAPK) was also assessed using a phospho-MAPK array. Activation of nuclear factor κB (NF-κB) was measured using an alkaline phosphatase reporter gene assay in THP1-Blue monocytic cells.

RESULTS

Six polysaccharide fractions from Alchornea cordifolia were isolated. Fractions containing type II arabinogalactan had potent immunomodulatory activity. Particularly, the parent fraction AP-AU and its high-molecular weight sub-fraction AP-AU1 (average M(r) was estimated to be 39.5kDa) induced production of NO and cytokines [interleukin (IL)-1β, -6, -10, tumor necrosis factor (TNF)-α, and granulocyte-macrophage-colony stimulating factor (GM-CSF)] in human peripheral blood mononuclear cells and human and murine monocyte/macrophages cell lines in vitro. Furthermore, treatment with AP-AU1 induced phosphorylation of Akt2, p38δ/p38γ, p70S6K1, RSK2, and mTOR, as well as stimulation of NF-κB transcriptional activity.

CONCLUSION

Our results provide a molecular basis to explain a portion of the beneficial therapeutic properties of water extracts from Alchornea cordifolia leaves in traditional folk medicine of Africa.

Inhibitory effects of medicinal mushrooms on α-amylase and α-glucosidase - enzymes related to hyperglycemia

In Asia, medicinal mushrooms have been popularly used as folk medicine and functional foods. In this study, our aim was to examine the inhibitory effects of six medicinal mushrooms on key enzymes (α-amylase and α-glucosidase) related to hyperglycemia; chemical profiles of bioactive extracts were also examined. The results showed that the n-hexane extract of Coriolus versicolor had the strongest anti-α-amylase activity, while the n-hexane extract of Grifola frondosa showed the most potent anti-α-glucosidase activity. Compared with acarbose, the anti-α-amylase activity of all mushroom extracts was weaker, however a stronger anti-α-glucosidase activity was noted. GC-MS analysis showed that the magnitude of potency of inhibiting α-glucosidase activity varied with the levels of oleic acid and linoleic acid present in the extracts. These findings were consistent with the IC50 values of these free fatty acids on inhibiting α-glucosidase activity. Taken together, this study suggests that oleic acid and linoleic acid could have contributed to the potent anti-α-glucosidase activity of selected medicinal mushrooms.