Characterization and antitumor effect of a novel polysaccharide from Grifola frondosa

A newly discovered glycosyltransferase gene UGT88A1 affects growth and polysaccharide synthesis of Grifola frondosa

Grifola frodosa polysaccharides, especially β-D-glucans, possess significant anti-tumor, antioxidant and immunostimulatory activities. However, the synthesis mechanism remains to be elucidated. A newly discovered glycosyltransferase UGT88A1 was found to extend glucan chains in vitro. However, the role of UGT88A1 in the growth and polysaccharide synthesis of G. frondosa in vivo remains unclear. In this study, the overexpression of UGT88A1 improved mycelial growth, increased polysaccharide production, and decreased cell wall pressure sensitivity. Biomass and polysaccharide production decreased in the silenced strain, and the pressure sensitivity of the cell wall increased. Overexpression and silencing of UGT88A1 both affected the monosaccharide composition and surface morphology of G. frondosa polysaccharides and influenced the antioxidant activity of polysaccharides from different strains. The messenger RNA expression of glucan synthase (GLS), UTP-glucose-1-phosphate uridylyltransferase (UGP), and UDP-xylose-4-epimerase (UXE) related to polysaccharide synthesis, and genes related to cell wall integrity increased in the overexpression strain. Overall, our study indicates that UGT88A1 plays an important role in the growth, stress, and polysaccharide synthesis of G. frondosa, providing a reference for exploring the pathway of polysaccharide synthesis and metabolic regulation. KEY POINTS: •UGT88A1 plays an important role in the growth, stress response, and polysaccharide synthesis in G. frondosa. •UGT88A1 affected the monosaccharide composition, surface morphology and antioxidant activity of G. frondosa polysaccharides. •UGT88A1 regulated the mRNA expression of genes related to polysaccharide synthesis and cell wall integrity.

Grifola frondosa polysaccharides: A review on structure/activity, biosynthesis and engineering strategies

Polysaccharides are the main polymers in edible fungi Grifola frondosa, playing a crucial role in the physiology and representing the healthy benefits for humans. Recent efforts have well elucidated the fine structures and biological functions of G. frondosa polysaccharides. The recently-rapid developments and increasing availability in fungal genomes also accelerated the better understanding of key genes and pathways involved in biosynthesis of G. frondosa polysaccharides. Herein, we provide a brief overview of G. frondosa polysaccharides and their activities, and comprehensively outline the complex process, genes and proteins corresponding to G. frondosa polysaccharide biosynthesis. The regulation strategies including strain improvement, process optimization and genetic engineering were also summarized for maximum production of G. frondosa polysaccharides. Some remaining unanswered questions in describing the fine synthesis machinery were also pointed out to open up new avenues for answering the structure-activity relationship and improving polysaccharide biosynthesis in G. frondosa. The review hopefully presents a reasonable full picture of activities, biosynthesis, and production regulation of polysaccharide in G. frondosa.

Therapeutic Potential of Bioactive Compounds from Edible Mushrooms to Attenuate SARS-CoV-2 Infection and Some Complications of Coronavirus Disease (COVID-19)

The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a highly infectious positive RNA virus, has spread from its epicenter to other countries with increased mortality and morbidity. Its expansion has hampered humankind's social, economic, and health realms to a large extent. Globally, investigations are underway to understand the complex pathophysiology of coronavirus disease (COVID-19) induced by SARS-CoV-2. Though numerous therapeutic strategies have been introduced to combat COVID-19, none are fully proven or comprehensive, as several key issues and challenges remain unresolved. At present, natural products have gained significant momentum in treating metabolic disorders. Mushrooms have often proved to be the precursor of various therapeutic molecules or drug prototypes. The plentiful bioactive macromolecules in edible mushrooms, like polysaccharides, proteins, and other secondary metabolites (such as flavonoids, polyphenols, etc.), have been used to treat multiple diseases, including viral infections, by traditional healers and the medical fraternity. Some edible mushrooms with a high proportion of therapeutic molecules are known as medicinal mushrooms. In this review, an attempt has been made to highlight the exploration of bioactive molecules in mushrooms to combat the various pathophysiological complications of COVID-19. This review presents an in-depth and critical analysis of the current therapies against COVID-19 versus the potential of natural anti-infective, antiviral, anti-inflammatory, and antithrombotic products derived from a wide range of easily sourced mushrooms and their bioactive molecules.

Microbial polysaccharides: An emerging family of natural biomaterials for cancer therapy and diagnostics

Microbial polysaccharides (MPs) offer immense diversity in structural and functional properties. They are extensively used in advance biomedical science owing to their superior biodegradability, hemocompatibility, and capability to imitate the natural extracellular matrix microenvironment. Ease in tailoring, inherent bio-activity, distinct mucoadhesiveness, ability to absorb hydrophobic drugs, and plentiful availability of MPs make them prolific green biomaterials to overcome the significant constraints of cancer chemotherapeutics. Many studies have demonstrated their application to obstruct tumor development and extend survival through immune activation, apoptosis induction, and cell cycle arrest by MPs. Synoptic investigations of MPs are compulsory to decode applied basics in recent inclinations towards cancer regimens. The current review focuses on the anticancer properties of commercially available and newly explored MPs, and outlines their direct and indirect mode of action. The review also highlights cutting-edge MPs-based drug delivery systems to augment the specificity and efficiency of available chemotherapeutics, as well as their emerging role in theranostics.

Structural Characteristics of Rehmannia glutinosa Polysaccharides Treated Using Different Decolorization Processes and Their Antioxidant Effects in Intestinal Epithelial Cells

Polysaccharide decolorization is a key determinant of polysaccharide structure. In this study, two purified Rehmannia glutinosa polysaccharides, RGP−1−A and RGP−2−A, were obtained after decolorization using the AB-8 macroporous resin and H₂O₂, respectively. RGP−1−A (molecular weight (Mw) = 18,964 Da) and RGP−2−A (Mw = 3305 Da) were acidic and neutral heteropolysaccharides, respectively, and were both polycrystalline in structure. FTIR analysis revealed that RGP−1−A was a sulfate polysaccharide, while RGP−2−A had no sulfate group. Experiments on IPEC-1 cells showed that RGPs alleviated oxidative stress by regulating the Nrf2/Keap1 pathway. These findings were confirmed by the upregulation of Nrf2, NQO1, and HO-1; the subsequent increase in the levels of antioxidant indicators (SOD, LDH, CAT, and MDA); and the restoration of mitochondrial membrane potential. Overall, the antioxidant capacity of RGP−1−A was significantly higher than that of RGP−2−A. These results suggest that RGPs may be a potential natural antioxidant and could be developed into functional foods.

Antitumor activities of Grifola frondosa (Maitake) polysaccharide: A meta-analysis based on preclinical evidence and quality assessment

ETHNOPHARMACOLOGICAL RELEVANCE

The antitumor effects of Grifola frondosa/maitake polysaccharide (GFP) have been reported in many preclinical studies, especially in vivo experiments. The present meta-analysis aimed to provide an in vivo evidence and theoretical basis for future clinical trials by assessing the efficacy and underlying mechanisms of GFP in tumor treatment.

MATERIALS AND METHODS

English and Chinese databases were examined to include animal experiments to study the antitumor activity of GFP. Literature screening, data extraction, and meta-analysis were conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. In addition, the Systematic Review Center for Laboratory animal Experimentation (SYRCLE) risk of bias (RoB) tool was used to assess the risk of bias of the included animal studies.

RESULTS

Potentially relevant studies (442) were identified, and finally 24 eligible studies (all in English) were included. The meta-analysis revealed that GFP has significant effects in inhibiting tumor growth (high dose: mean difference (MD) = -1.34, 95% confidence interval (CI) = [-1.73, -0.95]; low dose: MD = -5.68, 95% CI = [-7.27, -4.09]), improving tumor remission rate (odds ratio = 25.59, 95% CI = [9.08, 72.11]), and enhancing immune function in both cellular (CD4⁺ T cell percentage: MD = 3.03, 95% CI = [1.16, 4.90]; CD8⁺ T cell percentage: MD = 1.10, 95% CI = [-0.29, 2.49]) and humoral immunity (MD and [95% CI] of interleukin (IL)-2, IL-12 and tumor necrosis factor-α were 7.86 [6.29, 9.44], 35.95 [5.18, 66.72], and 10.03 [8.71, 11.36], respectively), and the differences between the two groups of the above indicators were statistically significant (all P < 0.01) except CD8⁺ T cell percentage. Additionally, the quality of the included studies was not high, and the risk of bias mainly concentrated on selection, detection, and reporting biases.

CONCLUSION

GFP is a potential candidate for tumor treatment and clinical trials.

TRIAL REGISTRATION

The review protocol for this study was registered with the PROSPERO database before beginning the review process (CRD42018108897).

Effects of Medicinal Fungi-Derived β-Glucan on Tumor Progression

β-Glucans have been studied in animal species, from earthworms to humans. They form a heterogenous group of glucose polymers found in fungi, plants, bacteria, and seaweed. β-Glucans have slowly emerged as an important target for the recognition of pathogens. In the current review, we highlight the major roles of mushroom-derived β-glucans on cancer progression.

Bioactive Ingredients and Medicinal Values of Grifola frondosa (Maitake)

Grifola frondosa (G. frondosa), generally known as hen-of-the-woods or maitake in Japanese and hui-shu-hua in Chinese, is an edible mushroom with both nutritional and medicinal properties. This review provides an up-to-date and comprehensive summary of research findings on its bioactive constituents, potential health benefits and major structural characteristics. Since the discovery of the D-fraction more than three decades ago, many other polysaccharides, including β-glucans and heteroglycans, have been extracted from the G. frondosa fruiting body and fungal mycelium, which have shown significant antitumor and immunomodulatory activities. Another class of bioactive macromolecules in G. frondosa is composed of proteins and glycoproteins, which have shown antitumor, immunomodulation, antioxidant and other activities. A number of small organic molecules such as sterols and phenolic compounds have also been isolated from the fungus and have shown various bioactivities. It can be concluded that the G. frondosa mushroom provides a diverse array of bioactive molecules that are potentially valuable for nutraceutical and pharmaceutical applications. More investigation is needed to establish the structure–bioactivity relationship of G. frondosa and to elucidate the mechanisms of action behind its various bioactive and pharmacological effects.

Anticancer and Immunomodulatory Effects of Polysaccharides

Cancer is one of the leading causes of death and one of the most important public health problems in the world. And every year, millions of new cancers and hundreds of thousands of cancer-related deaths are reported worldwide. In recent decades, a number of biologically active polysaccharides and polysaccharide-protein complexes have been isolated from plants, lichen, algae, yeast, fungi and mushroom, and due to their antitumor and immunomodulatory properties, these compounds have received considerable attention. Overall, the two key mechanisms by which polysaccharides act on tumor cells are direct action (inhibition of cancer cell growth and induction of programmed cell death/apoptosis) and indirect action (stimulation of immunity). Immunosuppressive effects are recognizable in both cancer patients and tumor bearing animals, suggesting that the immune system plays an important role in the immune surveillance of cancer cells. Thus, enhancement of the host immune response has been evaluated as a possible way of inhibiting tumor growth without damaging the host. In addition to their therapeutic and prophylactic properties, the polysaccharides are effective and less toxic than chemotherapy. The anticancer activity and immunomodulatory effects of most polysaccharides have shown the promising and real potential for the benefits of human health.

Antitumor, Anti-Inflammatory and Antiallergic Effects of Agaricus blazei Mushroom Extract and the Related Medicinal Basidiomycetes Mushrooms, Hericium erinaceus and Grifola frondosa: A Review of Preclinical and Clinical Studies

Since the 1980s, medicinal effects have been documented in scientific studies with the related Basidiomycota mushrooms Agaricus blazei Murill (AbM), Hericium erinaceus (HE) and Grifola frondosa (GF) from Brazilian and Eastern traditional medicine. Special focus has been on their antitumor effects, but the mushrooms' anti-inflammatory and antiallergic properties have also been investigated. The antitumor mechanisms were either direct tumor attack, e.g., apoptosis and metastatic suppression, or indirect defense, e.g., inhibited tumor neovascularization and T helper cell (Th) 1 immune response. The anti-inflammatory mechanisms were a reduction in proinflammatory cytokines, oxidative stress and changed gut microbiota, and the antiallergic mechanism was amelioration of a skewed Th1/Th2 balance. Since a predominant Th2 milieu is also found in cancer, which quite often is caused by a local chronic inflammation, the three conditions-tumor, inflammation and allergy-seem to be linked. Further mechanisms for HE were increased nerve and beneficial gut microbiota growth, and oxidative stress regulation. The medicinal mushrooms AbM, HE and GF appear to be safe, and can, in fact, increase longevity in animal models, possibly due to reduced tumorigenesis and oxidation. This article reviews preclinical and clinical findings with these mushrooms and the mechanisms behind them.

Immunomodulatory Effect of Structurally Characterized Mushroom Sclerotial Polysaccharides Isolated from Polyporus rhinocerus on Bone Marrow Dendritic Cells

This study evaluated the immunomodulatory effects of two high-molecular-weight and structurally different mushroom polysaccharides, an alkali-soluble polysaccharide (mPRSon) and a water-soluble polysaccharide-protein complex (PRW), isolated previously from the sclerotia of Pleurotus rhinocerus, on the maturation of murine bone-marrow-derived dendritic cells (BMDCs). The effects of mPRSon and PRW on the expression of morphological change, surface molecules, phagocytic activity, and cytokine release in BMDCs were determined by flow cytometry and a mouse cytokine array. The results showed that both mPRSon and PRW could induce phenotypic and functional maturation of BMDCs. At the same time, mPRSon upregulated the expression of membrane phenotypic marker CD86 and PRW markedly upregulated CD40, CD80, and CD86. In addition, mPRSon could bind to the dectin-1 receptor and stimulate the release of MIP-1α, MIP-2, and IL-2, while PRW could bind to complement receptor 3 and toll-like receptor 2 with an upregulation of the expression of IL-2, IL-6, MIP-1α, MIP-2, RANTES, IL-12p40p70, IL-12p70, TIMP-1, IFN-γ, KC, MCP-1, and GCSF. The study provides additional information on how structural differences in sclerotial polysaccharides influence their immunomodulatory activities on BMDCs involving different PAMP receptors. It is anticipated that more understanding of the interactions between the sclerotial polysaccharides and their receptors in immune cells can facilitate their future application for cancer immunotherapy.

In Vitro Anti-proliferative and Anti-invasive Effect of Polysaccharide-rich Extracts from Trametes Versicolor and Grifola Frondosa in Colon Cancer Cells

Colorectal cancer (CRC) is one of leading causes of mortality in western countries and novel treatment strategies are required. The medicinal application of mushrooms has been used in traditional medicine in many oriental countries. Polysaccharide-rich extracts obtained from certain medicinal mushroom species have shown antitumor effects in different experimental models. In the present study, we have developed polysaccharide-rich extracts from Trametes versicolor (TV) and Grifola frondosa (GF) fruit bodies. We aim to evaluate the anticancer effects of these polysaccharide-rich extracts in LoVo and HT-29 human colon cancer cells. The in vitro effects were determined by cytotoxicity assay, proliferation assay, wound healing assay and invasion assay. Moreover, the effect on anchorage independent-cell growth was also determined. Our results showed that TV and GF extracts did inhibit human colon cell proliferation and induce cytotoxicity. Furthermore, both fungal extracts significantly inhibited oncogenic potential, cell migration and invasion in colon cancer cells. In addition, extracts induce a more epithelial phenotype, observed by phase contrast images, together with an increase expression of the E-cadherin epithelial marker, detected by western-blotting analyses. Moreover, by using gelatin zymography assays, it was detected a decrease of MMP-2 enzyme activity, a crucial metalloproteinase important for the degradation of the extracellular matrix. Finally, the combination of the extracts with one the most clinical used agents for colorectal cancer, 5-fluorouracil, increases cell cytotoxicity. Taken together our results underscore a potential antitumor effect of polysaccharide-rich extracts obtained from TV and GF in human colon cancer cells lines. These finding may contribute to the reported health effects of fungal extracts.

Correlation of serum levels of IL-4, IFN-γ and TNF-α with clinicopathologic features in patients with gastric cancer

AIM

To detect the serum levels of interleukin-4 (IL-4), interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α) in gastric cancer (GC) patients and analyze their correlation with clinicopathologic features.

METHODS

A total of 50 GC patients and 50 healthy subjects were included in this study. We detected their serum levels of IL-4, IFN-γ and TNF-α by enzyme-linked immunosorbent assay and collected their clinicopathological data. Then we analyzed the correlation between the serum levels of IL-4, IFN-γ, TNF-α and the clinicopathologic features by spearman correlation analysis.

RESULTS

Compared to healthy subjects, serum levels of IL-4 and TNF-α significantly increased (57.62 pg/mL vs 42.63 pg/mL, P < 0.05; 315.08 pg/mL vs 34.21 pg/mL, P < 0.05), but serum level of IFN-γ significantly decreased (14.95 pg/mL vs 24.92 pg/mL, P < 0.05) in GC patients. There was a positive correlation between serum level of IL-4 and the depth of tumor invasion(r = 0.571, P < 0.05), but there was a negative correlation between serum level of IFN-γ and the number of metastatic lymph nodes (r = -0.526, P < 0.05) and depth of tumor invasion (r = -0.671, P < 0.05). Serum level of TNF-α was positively correlated with tumor differentiation (r = 0.816, P < 0.05).

CONCLUSION

GC patients have altered serum levels of IL-4, IFN-γ and TNF-α, and they may be related to the occurrence and development of GC, and have certain clinical value in predicting the biological behavior of GC and in developing treatment strategies.

Structural elucidation and antioxidant activity a novel Se-polysaccharide from Se-enriched Grifola frondosa

Se-GFP-22, a heteropolysaccharide, with a weight-average M_w of 4.13×10⁶Da, was purified from the crude Se-polysaccharide (Se-GFP) isolated from fruit bodies of Se-enriched Grifola frondosa. Selenium was accumulated efficiently in Grifola frondosa during cultivation with Na₂SeO₃. The structure was investigated through FT-IR, GC, GC-MS, NMR, HPSEC-MALL-RI, particle size, Conge-red test, CD, AFM and SEM. Se-GFP-22 was deduced as a backbone chain of 1,4-α-d-Glcp units with a branched point at C6 of both 1,3,6-β-d-Manp and 1,4,6-α-d-Galp units. A typical absorption for selenium ester was existed in Se-GFP-22. Se-GFP-22 adopted as a spherical conformation with random coils. A novel Se-polysaccharide of different monosaccharide constituents, molecular weight, linkage types and high content of selenium has been isolated from G. frondosa. The antioxidant effect of Se-GFP-22 was more potent than that of G. frondosa polysaccharide (GFP-22), which may be influenced by the co-effect of polysaccharide and Se, molecular weight, degree of branching and configuration.

In Vitro Effects of Some Botanicals with Anti-Inflammatory and Antitoxic Activity

Several extrinsic factors, like drugs and chemicals, can foster autoimmunity. Tetracyclines, in particular oxytetracycline (OTC), appear to correlate with the emergence of immune-mediated diseases. Accumulation of OTC, the elective drug for gastrointestinal and respiratory infectious disease treatment in broiler chickens, was reported in chicken edible tissues and could represent a potential risk for pets and humans that could assume this antibiotic as residue in meat or in meat-derived byproducts. We investigated the in vitro anti-inflammatory properties of a pool of thirteen botanicals as a part of a nutraceutical diet, with proven immunomodulatory activity. In addition, we evaluated the effect of such botanicals in contrasting the in vitro proinflammatory toxicity of OTC. Our results showed a significant reduction in interferon- (INF-) γ production by human and canine lymphocytes in presence of botanicals ((⁎) p < 0.05). Increased INF-γ production, dependent on 24-hour OTC-incubation of T lymphocytes, was significantly reduced by the coincubation with Haematococcus pluvialis, with Glycine max, and with the mix of all botanicals ((⁎) p < 0.05). In conclusion, the use of these botanicals was shown to be able to contrast OTC-toxicity and could represent a new approach for the development of functional foods useful to enhance the standard pharmacological treatment in infections as well as in preventing or reducing the emergence of inflammatory diseases.

Cold-water extracts of Grifola frondosa and its purified active fraction inhibit hepatocellular carcinoma in vitro and in vivo

Mushrooms are used in traditional Chinese medicine to treat a variety of diseases. Grifola frondosa (GF) is an edible mushroom indigenous to many Asian countries with a large fruiting body characterized by overlapping caps. In particular, GF is known for its anti-tumor activity, which has been targeted by scientific and clinical research. This study aimed to investigate the effects of the cold-water extract of GF (GFW) and its active fraction (GFW-GF) on autophagy and apoptosis, and the underlying mechanisms in vitro and in vivo Our results revealed that GFW and GFW-GF inhibited phosphatidylinositol 3-kinase (PI3K) and stimulated c-Jun N-terminal kinase (JNK) pathways, thereby inducing autophagy. We also demonstrated that GFW and GFW-GF inhibited proliferation, induced cell cycle arrest, and apoptosis in Hep3B hepatoma cells. GFW and GFW-GF markedly arrested cells in S phase and promoted cleavage of caspase-3 and -9. In addition, GFW and GFW-GF decreased the expression levels of the anti-apoptotic proteins protein kinase B and extracellular signal-regulated kinase. We also found that GFW significantly inhibited tumor growth in nude mice implanted with Hep3B cells. Our work demonstrates that GF and its active fraction inhibit hepatoma growth by inducing autophagy and apoptosis.

Soluble β-glucan from Grifola frondosa induces tumor regression in synergy with TLR9 agonist via dendritic cell-mediated immunity

The maturation of dendritic cells into more-immunostimulatory dendritic cells by stimulation with different combinations of immunologic agents is expected to provide efficient, adoptive immunotherapy against cancer. Soluble β-glucan maitake D-fraction, extracted from the maitake mushroom Grifola frondosa, acts as a potent immunotherapeutic agent, eliciting innate and adoptive immune responses, thereby contributing to its antitumor activity. Here, we evaluated the efficacy of maitake D-fraction, in combination with a Toll-like receptor agonist, to treat tumors in a murine model. Our results showed that maitake D-fraction, in combination with the Toll-like receptor 9 agonist, cytosine-phosphate-guanine oligodeoxynucleotide, synergistically increased the expression of dendritic cell maturation markers and interleukin-12 production in dendritic cells, but it did not increase interleukin-10 production, generating strong effector dendritic cells with an augmented capacity for efficiently priming an antigen-specific, T helper 1-type T cell response. Maitake D-fraction enhances cytosine-phosphate-guanine oligodeoxynucleotide-induced dendritic cell maturation and cytokine responses in a dectin-1-dependent pathway. We further showed that a combination therapy using cytosine-phosphate-guanine oligodeoxynucleotide and maitake D-fraction was highly effective, either as adjuvants for dendritic cell vaccination or by direct administration against murine tumor. Therapeutic responses to direct administration were associated with increased CD11c(+) dendritic cells in the tumor site and the induction of interferon-γ-producing CD4(+) and CD8(+) T cells. Our results indicate that maitake D-fraction and cytosine-phosphate-guanine oligodeoxynucleotide synergistically activated dendritic cells, resulting in tumor regression via an antitumor T helper cell 1-type response. Our findings provide the basis for a potent antitumor therapy using a novel combination of immunologic agents for future clinical immunotherapy studies in patients.

Polysaccharides from Cymbopogon citratus with antitumor and immunomodulatory activity

Abstract Context: Most of the present studies on the antitumor efficiency of Cymbopogon citratus (DC.) Stapf (Gramineae) are limited to its low-mass compounds, and little information about the antitumor activity of polysaccharides from this plant is available.

OBJECTIVES

This study focused on the potential antitumor and immunomodulatory activities of polysaccharides (CCPS) from C. citratus.

MATERIALS AND METHODS

CCPS was isolated using the water extraction-ethanol precipitation method. The sarcoma 180 (S180) cells-inoculated mice were intraperitoneally administrated with CCPS (30-200 mg/kg/d) for seven consecutive days. The effects of CCPS on tumor growth, thymus and spleen weights, splenocyte proliferation, and cytokine secretion in the tumor-bearing mice were measured. The cytotoxicity of CCPS (50-800 μg/mL) towards S180 cells was also studied.

RESULTS

CCPS significantly inhibited the growth of the transplanted S180 tumors, with the inhibition rates ranging from 14.8 to 37.8%. Simultaneously, CCPS dose-dependently improved the immunity of the tumor-bearing mice. With the highest dose of 200 mg/kg/d, the thymus and spleen indices were increased by 21.9 and 91.9%, respectively; ConA- and LSP-induced splenocyte proliferations were increased by 32.7 and 35.3%, respectively. The secretions of interleukin 2 (IL-2), interleukin 6 (IL-6), interleukin 2 (IL-12), and tumor necrosis factor-α (TNF-α) were increased by 103.2, 40.2, 23.6, and 26.3%, respectively. Nevertheless, almost no toxicity of CCPS towards S180 cells was observed, with the maximal inhibition rate less than 15% at the CCPS concentration of 800 μg/mL.

CONCLUSION

CCPS exhibited antitumor activity in vivo, and this activity might be achieved by immunoenhancement rather than direct cytotoxicity.

A polysaccharide from Salvia miltiorrhiza Bunge improves immune function in gastric cancer rats

A neutral polysaccharide fraction (SMPA) prepared from the roots of Salvia miltiorrhiza by DEAE-cellulose and Sephadex G-100 chromatography was tested for its immune enhancing function in N-methyl-N'-nitro-nitrosoguanidine (MNNG)-induced gastric cancer rats by intragastric administration. SMPA (200mg/kg) treatment not only increased the body weight, but also improved the immune organ indices. Furthermore, studies of various immunological activities in gastric cancer rats revealed that SMPA significantly stimulated splenocyte proliferation, promoted anti-inflammatory cytokines (IL-2, IL-4 and IL-10) production, inhibited pro-inflammatory cytokine (IL-6 and TNF-α) secretion, augmented the killing activity of natural killer (NK) cells and cytotoxic T lymphocytes (CTL), and increased phagocytotic function of macrophages in gastric cancer rats. In addition, SMPA administration evidently elevated total intracellular granzyme-B and IFN-γ levels produced by splenocytes in gastric cancer rats. Taken together, these results suggested that SMPA could act as an effective immunomodulator and might be explored as a potential supplemental source for gastric cancer therapy.

Effects of various heat treatments on phenolic profiles and antioxidant activities of Pleurotus eryngii extracts

Free (FP) and bound phenolics (BP) were extracted from freeze dried (FD), oven dried (OD), as well as boiling treated (BT) Pleurotus eryngii samples. Free, bound, total phenolics were quantified using Folin-Ciocalteau assay. Qualitative and quantitative analysis of phenolic compounds were carried out using high-performance liquid chromatography (HPLC) coupled with diode array detector (DAD), and a total of 8 phenolic compounds were detected. Free phenolic contents followed the order: Freeze-dried free phenolics (FDFP) > Oven-dried free phenolics (ODFP) > Boiling-treated free phenolics (BTFP), and ranged from 95.42 (BTFP) to 442.50 (ODPF) μg gallic acid equivalents (GAE)/g dry weight (DW). Bound and total phenolic contents followed the order: FD > OD > BT, and ranged from 218.33 (BTBP) to 774.17 (FDBP) and 313.75 (BT total phenolics) to 1090.42 (FD total phenolics) μg GAE/g DW. Bound phenolics contributed 49.76% (OD), 69.59% (BT), and 71% (FD) of the total phenolic contents. All free and bound phenolic extracts were investigated for their antioxidant activities by 3 different assays, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, reducing power, and superoxide anion radical scavenging activity. FDFP showed strongest DPPH radical scavenging activity (IC50 at 32.61 μg/mL), ODFP showed strongest reducing power (IC50 at 26.31 μg/mL), and BTBP showed strongest superoxide anion radical scavenging activity (IC50 at 14.07 μg/mL).

Characterization of a novel maitake (Grifola frondosa) protein that activates natural killer and dendritic cells and enhances antitumor immunity in mice

Grifola frondosa, also known as maitake, is a culinary mushroom with immune-enhancing and antitumor effects. Numerous studies have investigated the activity of maitake polysaccharide extracts, but studies of maitake proteins are scarce. In this study, we purified and characterized a new G. frondosa protein, GFP, from maitake fruiting bodies. GFP is a nonglucan heterodimeric 83 kDa protein that consists of two 41 kDa subunits. GFP induced interferon-γ secretion by murine splenocytes and natural killer cells and activated the maturation of bone marrow-derived dendritic cells (BMDCs) via a TLR4-dependent mechanism. GFP-treated BMDCs promoted a Th1 response and exhibited significant antitumor activity when transferred into tumor-bearing mice. In conclusion, we are the first to reveal the critical role of GFP in modulating the immune response and to link the immune-enhancing effects of maitake to its antitumor activities.

Oral administration of soluble β-glucans extracted from Grifola frondosa induces systemic antitumor immune response and decreases immunosuppression in tumor-bearing mice

Maitake D (MD)-Fraction is a highly purified soluble β-glucan derived from Grifola frondosa (an oriental edible mushroom). Intraperitoneal (i.p.) injection of MD-Fraction has been reported to inhibit tumor growth via enhancement of the host immune system. In this study, we demonstrated that oral administration of MD-Fraction as well as i.p. injection significantly inhibited tumor growth in murine tumor models. After oral administration, MD-Fraction was not transferred to the blood in its free form but was captured by antigen-presenting cells such as macrophages and dendritic cells (DCs) present in the Peyer's patch. The captured MD-Fraction was then transported to the spleen, thereby inducing the systemic immune response. Our study showed that MD-Fraction directly induced DC maturation via a C-type lectin receptor dectin-1 pathway. The therapeutic response of orally administered MD-Fraction was associated with (i) induced systemic tumor-antigen specific T cell response via dectin-1-dependent activation of DCs, (ii) increased infiltration of the activated T cells into the tumor and (iii) decreased number of tumor-caused immunosuppressive cells such as regulatory T cells and myeloid-derived suppressor cells. Our preclinical study suggests that MD-Fraction is a useful oral therapeutic agent in the management of patients with cancer.

Structure and antioxidant activity of polysaccharide POJ-U1a extracted by ultrasound from Ophiopogon japonicus

An ultrasonic technique was employed to extract polysaccharides from Ophiopogon japonicus. The ultrasonic extracted polysaccharides (POJ-U) were purified, and POJ-U1a (a homogeneous fraction) was obtained. The structural characteristics of POJ-U1a were investigated by infrared spectra, gas chromatography, high performance liquid chromatography, periodate oxidation, Smith degradation, methylation analysis, gas chromatography-mass spectrometry and nuclear magnetic resonance spectroscopy. The results indicated that the relative molecular weight of POJ-U1a was 4.02×10(3)Da. POJ-U1a was an α-configuration polysaccharide with a highly branched structure, and consisted of pyranoside and funanside. The backbone of POJ-U1a consisted of 1,6-α-d-glucopyranose and 1,3,6-α-d-glucofuranose in the molar ratio of 7:3, while the branched chains were mainly composed of 1,3-α-d-glucopyranose and 1-α-d-glucopyranose in the molar ratio of 1:3. The branched structure of POJ-U1a was proved intuitively by AFM. Significant antioxidant activity of POJ-U1a has been proved as shown by its DPPH radical scavenging, hydrogen radical scavenging and superoxide anion scavenging activities, which indicated that POJ-U1a showed strong antioxidant activity.

Modulatory effects of the acid polysaccharide fraction from one of anamorph of Cordyceps sinensis on Ana-1 cells

ETHNOPHARMACOLOGICAL RELEVANCE

Cordyceps sinensis has been used as a precious herbal medicine for thousands of years in China. Its polysaccharide fraction has been confirmed possessing immunomodulatory function and we have reported the acid polysaccharide fraction (APSF), from an anamorph of C. sinensis, has stimulating activity on macrophages. The mechanism still needs to be further elucidated.

MATERIALS AND METHODS

In order to investigate the effects of APSF on macrophage's phenotypes, Ana-1 mouse macrophages were polarized to M2 phenotype by culturing the cells with culture supernatant of H22 cells. M2 phenotype was determined by measuring the expression of TNF-α and checking cell surface markers mannose receptor (MR) and scavenger receptor (SR). After cultured with H22 supernatant for 72 h, the TNF-α level of Ana-1 cells was decreased while the SR and MR expressions were up-regulated, suggesting that Ana-1 cells were polarized towards M2 macrophages. Then the effects of APSF on M2 macrophages were investigated by measuring mRNA levels of TNF-α, inducible nitric oxide synthase (iNOS), IL-12 and IL-10. Nuclear NF-κB was detected by Western blotting.

RESULTS

APSF treatment increased the expressions of TNF-α, IL-12 and iNOS, and reduced the expression of IL-10 of Ana-1 cells. Besides, the expressions of SR and MR were down-regulated by APSF. And the result of Western blotting showed NF-κB level was decreased in M2 macrophages and up-regulated after APSF treatment.

CONCLUSIONS

APSF may convert M2 macrophages to M1 phenotype by activating NF-κB pathway.

Anticancer polysaccharides from natural resources: a review of recent research

Taking into account the rising trend of the incidence of cancers of various organs, effective therapies are urgently needed to control human malignancies. However, almost all of the chemotherapy drugs currently on the market cause serious side effects. Fortunately, several previous studies have shown that some non-toxic biological macromolecules, including polysaccharides and polysaccharide-protein complexes, possess anti-cancer activities or can increase the efficacy of conventional chemotherapy drugs. Based on these encouraging observations, a great deal of effort has been focused on discovering anti-cancer polysaccharides and complexes for the development of effective therapeutics for various human cancers. This review focuses on the advancements in the anti-cancer efficacy of various natural polysaccharides and polysaccharide complexes in the past 5 years. Most polysaccharides were tested using model systems, while several involved clinical trials.

Optimization of culture medium for enhanced production of exopolysaccharide from Aureobasidium pullulans

Polysaccharides produced by microorganisms are utilized for a variety of purposes, including the use in cosmetics and as food additives. More recently, polysaccharides have been exploited by the medical and pharmaceutical industries, and those originated from many species of mushrooms have been especially useful in industrial applications; however, the production and synthesis of these compounds is costly and time consuming. In this study, we developed a method for low-cost production of exopolysaccharide (EPS) that effectively screens components and optimizes medium composition using statistical methods (Plackett-Burman and Box-Behnken design). As a result, we obtained the following optimized medium: sucrose 165.73 g/L, sodium nitrate 3.08 g/L, dipotassium phosphate 1.00 g/L, potassium chloride 0.50 g/L, magnesium sulfate 0.50 g/L, ferrous sulfate 0.01 g/L, and 0.71 g/L of Ashbya gossypii extract. The maximum production of about 29 g/L EPS was achieved in the optimized medium during 84 h batch fermentation.

Antioxidant properties and antioxidant compounds of various extracts from the edible basidiomycete Grifola frondosa (Maitake)

Grifola frondosa is an edible mushroom currently available in Taiwan. Ethanolic, cold-water and hot-water extracts were prepared and their antioxidant properties were investigated. At 1 mg/mL, G. frondosa T1 and T2 cold-water extracts showed high reducing powers of 1.02 and 0.50, respectively. Chelating abilities on ferrous ions of G. frondosa T1 and T2 were higher for cold-water extracts than for ethanolic and hot-water extracts. For the scavenging ability on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, G. frondosa T1 and T2 extracts were effective in the following order: ethanolic > hot-water > cold-water. The G. frondosa hot-water extract showed high scavenging ability on superoxide anions. Total phenols, flavonoids, ascorbic acid and α-tocopherol are the major antioxidant components found in the various G. frondosa extracts. Based on EC₅₀ values (<20 mg/mL) obtained, the various extracts from G. frondosa investigated in this study display potent antioxidative properties.

A polysaccharide extracted from Grifola frondosa enhances the anti-tumor activity of bone marrow-derived dendritic cell-based immunotherapy against murine colon cancer

We previously isolated the novel heteropolysaccharide maitake Z-fraction (MZF) from the maitake mushroom (Grifola frondosa), and demonstrated that MZF significantly inhibited tumor growth by inducing cell-mediated immunity. In this study, we demonstrated that MZF upregulated the expression of CD80, CD86, CD83, and MHC II on bone marrow-derived dendritic cells (DCs) and significantly increased interleukin-12 (IL-12) and tumor necrosis factor-alpha production by DCs in a dose-dependent manner. MZF-treated DCs significantly stimulated both allogeneic and antigen-specific syngenic T cell responses and enhanced antigen-specific interferon-gamma (IFN-gamma) production by syngenic CD4(+) T cells; however, MZF-treated DCs did not affect IL-4 production. Furthermore, the enhancement of IFN-gamma production in CD4(+) T cells, which was induced by MZF-treated DCs, was completely inhibited by the addition of an anti-IL-12 antibody. These results indicate that MZF induced DC maturation and antigen-specific Th1 response by enhancing DC-produced IL-12. We also demonstrated that DCs pulsed with colon-26 tumor lysate in the presence of MZF induced both therapeutic and preventive effects on colon-26 tumor development in BALB/c mice. These results suggest that MZF could be a potential effective adjuvant to enhance immunotherapy using DC-based vaccination.

Extraction optimization and in vivo antioxidant activities of exopolysaccharide by Morchella esculenta SO-01

Response surface methodology was used to optimize extraction parameters for Morchella esculenta SO-01 exopolysaccharide (EPS) produced during submerged culture. The optimum conditions for EPS extraction were predicted to be, concentration at 84.07 degrees C, precipitation for 22.19 h and pH 8.44, and EPS production was estimated at 5.45 g/L. The actual yield of EPS under these conditions was 5.32 g/L. The antioxidant capacity of the EPS was measured in vivo after filling the stomach with different doses of EPS and results showed that the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) of blood, spleen, liver, heart, and kidney were increased by 125%, 46.11%, 23.33%, 12.19%, 41.29%, and 63.24%, 63.12%, 166.54%, 98.01%, 57.68%, respectively, and that malonaldehyde (MDA) of blood, spleen, liver, heart, and kidney were decreased by 21.80%, 67.84%, 28.48%, 56.15%, 41.62%. The results provide a reference for large-scale extraction of EPS by M. esculenta SO-01 in industrial fermentation.