Beta-glucan extracted from the medicinal mushroom Agaricus blazei prevents the genotoxic effects of benzo[a]pyrene in the human hepatoma cell line HepG2

Dietary Intake of Yeast-Derived β-Glucan and Rice-Derived Arabinoxylan Induces Dose-Dependent Innate Immune Priming in Mice

Beta-glucans and arabinoxylans are known for their immunostimulatory properties. However, in vivo these have been documented almost exclusively following parenteral administration, underemphasizing oral intake. C57BL/6 mice are fed either a control diet or a diet supplemented with yeast-derived whole β-glucan particle (yWGP) or with rice-derived arabinoxylan (rice bran-1) at a concentration of 1%, 2.5%, or 5% weight/weight (w/w) for 2 weeks. Thereafter, cells from blood, bone marrow, and spleen are collected for ex vivo stimulation with various microbial stimuli. Dietary intake of yWGP for 2 weeks at concentrations of 1% and 2.5% w/w increases ex vivo cytokine production in mouse blood and bone marrow, whereas 5% w/w yWGP shows no effect. In the spleen, cytokine production remains unaffected by yWGP. At a concentration of 1% w/w, rice bran-1 increases ex vivo cytokine production by whole blood, but 2.5% and 5% w/w cause inhibitory effects in bone marrow and spleen. This study demonstrates that dietary yWGP and rice bran-1 induce immune priming in mouse blood and bone marrow, with the strongest effects observed at 1% w/w. Future human trials should substantiate the efficacy of dietary β-glucans and arabinoxylans to bolster host immunity, focusing on dose optimization.

Research progress on the mechanisms underlying poultry immune regulation by plant polysaccharides

With the rapid development of poultry industry and the highly intensive production management, there are an increasing number of stress factors in poultry production. Excessive stress will affect their growth and development, immune function, and induce immunosuppression, susceptibility to a variety of diseases, and even death. In recent years, increasing interest has focused on natural components extracted from plants, among which plant polysaccharides have been highlighted because of their various biological activities. Plant polysaccharides are natural immunomodulators that can promote the growth of immune organs, activate immune cells and the complement system, and release cytokines. As a green feed additive, plant polysaccharides can not only relieve stress and enhance the immunity and disease resistance of poultry, but also regulate the balance of intestinal microorganisms and effectively alleviate all kinds of stress faced by poultry. This paper reviews the immunomodulatory effects and molecular mechanisms of different plant polysaccharides (Atractylodes macrocephala Koidz polysaccharide, Astragalus polysaccharides, Taishan Pinus massoniana pollen polysaccharide, and alfalfa polysaccharide) in poultry. Current research results reveal that plant polysaccharides have potential uses as therapeutic agents for poultry immune abnormalities and related diseases.

Polysaccharides and extracts from Agaricus brasiliensis Murill - A comprehensive review

Edible mushrooms have been increasingly introduced into the human diet, which has driven research into their functional properties. Thus, Agaricus brasiliensis Murill or Agaricus blazei Murill (ABM) is a species native to the Brazilian biome, whose fruiting body has been used not only for dietary purposes, but also in the development of functional foods or as source of molecules of pharmacological interest. The bioactivity of ABM has been related to the presence of polysaccharides, although the contribution of other metabolites cannot be discharged. This work describes the polysaccharides isolation methodology and preparation of the extracts of ABM and their biological activities. Furthermore, it presents a general outline of its characterizations regarding composition, chemical structure and properties in solution. The ABM and its chemical constituents exhibit several biological activities that support their potential use for prevention or treatment of diseases with inflammatory background, such as cancer, diabetes and atherosclerosis. The mechanism of action of the extracts and polysaccharides from ABM is mainly related to a modulation of immune system response or reduction of inflammatory response. This review shows that the ABM has great potential in the pharmaceutical, biotechnological and food sectors that deserves additional research using standardized products.

Assessment of Antioxidant Effect of Beta-Glucan on the Whole Blood Oxidative DNA Damage with the Comet Assay in Colorectal Cancer

OBJECTIVE

The present study aims to evaluate the antioxidant effect of beta glucan on oxidative DNA damage by comet assay.

METHODS

A total of 19 adult females and males diagnosed with stage 3-4 colorectal cancer and a control group of 20 age-matched healthy subjects were enrolled in the study. Blood samples of the participants were analyzed using Comet Assay for the parameters of DNA damage.

RESULTS

Significantly increased DNA damage was observed in patients versus control group as indicated by greater values of tail moment, tail percent DNA and tail length. Following incubation with β-glucan, a substantial reduction was found in the aforementioned parameters of DNA damage. Comet assay revealed significant levels of endogenous DNA damage in patients as shown by remarkable increases in the tail moment, the percentage of DNA in the tail and the tail length values, in comparison with the control group. Following treatment of fresh whole blood with β-glucan incubation, DNA damages were significantly reduced but lower values were observed after β-glucan incubation in the patient group versus control group.

CONCLUSION

β-Glucan was found to reduce DNA damage substantially in colorectal cancer patients and show antimutagenic effects. Our results suggested that dietary β-glucan intake might be important in the genesis of colorectal cancer tumors.

Agaricus brasiliensis Mushroom Protects Against Sepsis by Alleviating Oxidative and Inflammatory Response

Sepsis is characterized by the host's dysregulated immune response to an infection followed by a potentially fatal organ dysfunction. Although there have been some advances in the treatment of sepsis, mainly focused on broad-spectrum antibiotics, mortality rates remain high, urging for the search of new therapies. Oxidative stress is one of the main features of septic patients, so antioxidants can be a good alternative treatment. Agaricus brasiliensis is a nutraceutical rich in bioactive compounds such as polyphenols and polysaccharides, exhibiting antioxidant, antitumor, and immunomodulatory activities. Here, we investigated the immunomodulatory and antioxidant effects of A. brasilensis aqueous extract in the cecal ligation and puncture (CLP) sepsis model. Our data showed that aqueous extract of A. brasiliensis reduced systemic inflammatory response and improved bacteria clearance and mice survival. In addition, A brasiliensis decreased the oxidative stress markers in serum, peritoneal cavity, heart and liver of septic animals, as well as ROS production (in vitro and in vivo) and tert-Butyl hydroperoxide-induced DNA damage in peripheral blood mononuclear cells from healthy donors in vitro. In conclusion, the aqueous extract of A. brasiliensis was able to increase the survival of septic animals by a mechanism involving immunomodulatory and antioxidant protective effects.

Natural Products Mediated Targeting of Virally Infected Cancer

The role of viral infection in developing cancer was determined in the start of 20th century. Until now, 8 different virus-associated cancers have been discovered and most of them progressed in immunosuppressed individuals. The aim of the present study is to look into the benefits of natural products in treating virally infected cancers. The study focuses on bioactive compounds derived from natural sources. Numerous pharmaceutical agents have been identified from plants (vincristine, vinblastine, stilbenes, combretastatin, and silymarin), marine organisms (bryostatins, cephalostatin, ecteinascidins, didemnin, and dolastatin), insects (cantharidin, mastoparan, parectadial, and cecropins), and microorganisms (vancomycin, rhizoxin, ansamitocins, mitomycin, and rapamycin). Beside these, various compounds have been observed from fruits and vegetables which can be utilized in anticancer therapy. These include curcumin in turmeric, resveratrol in red grapes, S-allyl cysteine in allium, allicin in garlic, catechins in green tea, and β-carotene in carrots. The present study addresses various types of virally infected cancers, their mechanism of action, and the role of different cell surface molecules elicited during viral binding and entry into the target cell along with the anticancer drugs derived from natural products by targeting screening of bioactive compounds from natural sources.

Clinical and Physiological Perspectives of β-Glucans: The Past, Present, and Future

β-Glucans are a group of biologically-active fibers or polysaccharides from natural sources with proven medical significance. β-Glucans are known to have antitumor, anti-inflammatory, anti-obesity, anti-allergic, anti-osteoporotic, and immunomodulating activities. β-Glucans are natural bioactive compounds and can be taken orally, as a food supplement, or as part of a daily diet, and are considered safe to use. The medical significance and efficiency of β-glucans are confirmed in vitro, as well as using animal- and human-based clinical studies. However, systematic study on the clinical and physiological significance of β-glucans is scarce. In this review, we not only discuss the clinical and physiological importance of β-glucans, we also compare their biological activities through the existing in vitro and animal-based in vivo studies. This review provides extensive data on the clinical study of β-glucans.

Antioxidant and antigenotoxic potential of Ramaria largentii Marr & D. E. Stuntz, a wild edible mushroom collected from Northeast Romania

Ramaria largentii Marr & D. E. Stuntz (orange coral mushroom) is a wild edible mushroom whose chemical composition and bioactivity have not been investigated. Herein, we present a study on the phenolic constituents, antioxidant and antigenotoxic effects of a hydromethanolic extract of the fruiting bodies. Total phenolic content, estimated by Folin-Ciocalteu assay, was found to be 42.33 ± 0.18 mg GAE/g. Protocatechuic and vanillic acids were detected by HPLC-DAD-ESI-MS. The extract showed good free radical scavenging and reducing capacities (EC₅₀ = 64.3 ± 0.2 and 61.54 ± 0.46 μg/mL, respectively). In normal Vero cells, the extract (100, 200 and 300 μg/mL) showed no genotoxic potential and moreover, almost completely protected DNA against H₂O₂-induced damage (2.09-7.91% tail DNA) (24 and 48 h pre-treatment). Taken together, the results of our study show that Ramaria largentii extract is devoid of genotoxicity and has a remarkable DNA protective activity against H₂O₂-induced damage.

Evidence of Some Natural Products with Antigenotoxic Effects. Part 1: Fruits and Polysaccharides

Cancer is one of the leading causes of deaths worldwide. The agents capable of causing damage to genetic material are known  as genotoxins and, according to their mode of action, are classified into mutagens, carcinogens or teratogens. Genotoxins are  involved in the pathogenesis of several chronic degenerative diseases including hepatic, neurodegenerative and cardiovascular  disorders, diabetes, arthritis, cancer, chronic inflammation and ageing. In recent decades, researchers have found novel bioactive  phytocompounds able to counteract the effects of physical and chemical mutagens. Several  studies  have  shown potential antigenotoxicity in a variety of fruits. In this review (Part 1), we present an overview of research conducted on some fruits (grapefruit, cranberries, pomegranate, guava, pineapple, and mango) which are frequentl consumed by humans, as well as  the  analysis of some phytochemicals extracted from fruits and yeasts which have demonstrated antigenotoxic capacity in various  tests, including the Ames assay, sister chromatid exchange, chromosomal aberrations, micronucleus and comet assay.

Mesenchymal stem cell therapy promotes the improvement and recovery of renal function in a preclinical model

Acute renal failure (ARF) is an extremely important public health issue in need of novel therapies. The present study aimed to evaluate the capacity of mesenchymal stem cell (MSC) therapy to promote the improvement and recovery of renal function in a preclinical model. Wistar rats were used as the experimental model, and our results show that cisplatin (5mg/kg) can efficiently induce ARF, as measured by changes in biochemical (urea and creatinine) and histological parameters. MSC therapy performed 24h after the administration of chemotherapy resulted in normalized plasma urea and creatinine levels 30 and 45d after the onset of kidney disease. Furthermore, MSC therapy significantly reduced histological changes (intratubular cast formation in protein overload nephropathy and tubular hydropic degeneration) in this ARF model. Thus, considering that current therapies for ARF are merely palliative and that MSC therapy can promote the improvement and recovery of renal function in this model system, we suggest that innovative/alternative therapies involving MSCs should be considered for clinical studies in humans to treat ARF.

Protective effects of the exopolysaccharide Lasiodiplodan against DNA damage and inflammation induced by doxorubicin in rats: Cytogenetic and gene expression assays

The lasiodiplodan (LS) is a β-(1→6)-d-glucan produced by the fungus Lasiodiplodia theobromae and some of the biological activities of LS were reported as hypoglycemic, anticoagulant, anti-proliferative and anticancer action; however, its effects on DNA instability and modulation of gene expression are still unclear. Aims of study were investigate the genotoxic effects of lasiodiplodan, and its protective activity against DNA damage induced by doxorubicin (DXR) and its impact on the expression of genes associated with DNA damage and inflammatory response pathways. Therefore, Wistar rats were treated (15 days) orally with LS (5.0; 10 and 20mg/kg bw) alone and in combination with DXR (15mg/kg bw; administrated intraperitoneally on 14th day) as well as their respective controls: distilled water and DXR. Monitoring of DNA damage was assessed by comet and micronucleus (MN) assays and gene expression was evaluated by PCR-Arrays. Treatments with LS alone did not induce disturbances on DNA; when LS was given in combination with DXR, comet and MN formations were reduced to those found in the respective controls. Moreover, LS was able to reduce the disturbances on gene expressions induced by DXR treatment, since the animals that receive LS associated with DXR showed no alteration in the expression of genes related to DNA damage response. Also, DXR induced several up- and down-regulation of several genes associated to inflammatory process, while the animals that received LS+DXR had their gene expression patterns similar to those found in the control group. In conclusion, our results showed that LS did not induce disturbances on DNA stability and significantly reduce the DNA damage and inflammation caused by DXR exposure. In addition, we give further information concerning the molecular mechanisms associated to LS protective effects which seems to be a promising nutraceutical with chemopreventive potential.

Dietary Natural Products for Prevention and Treatment of Liver Cancer

Liver cancer is the most common malignancy of the digestive system with high death rate. Accumulating evidences suggests that many dietary natural products are potential sources for prevention and treatment of liver cancer, such as grapes, black currant, plum, pomegranate, cruciferous vegetables, French beans, tomatoes, asparagus, garlic, turmeric, ginger, soy, rice bran, and some edible macro-fungi. These dietary natural products and their active components could affect the development and progression of liver cancer in various ways, such as inhibiting tumor cell growth and metastasis, protecting against liver carcinogens, immunomodulating and enhancing effects of chemotherapeutic drugs. This review summarizes the potential prevention and treatment activities of dietary natural products and their major bioactive constituents on liver cancer, and discusses possible mechanisms of action.

Prevention of Aflatoxin B₁-Induced DNA Breaks by β-D-Glucan

Aflatoxins are a group of naturally-occurring carcinogens that are known to contaminate different human and animal foodstuffs. Aflatoxin B1 (AFB1) is the most genotoxic hepatocarcinogenic compound of all of the aflatoxins. In this report, we explore the capacity of β-D-glucan (Glu) to reduce the DNA damage induced by AFB1 in mouse hepatocytes. For this purpose, we applied the comet assay to groups of animals that were first administered Glu in three doses (100, 400 and 700 mg/kg bw, respectively) and, 20 min later, 1.0 mg/kg of AFB1. Liver cells were obtained at 4, 10 and 16 h after the chemical administration and examined. The results showed no protection of the damage induced by AFB1 with the low dose of the polysaccharide, but they did reveal antigenotoxic activity exerted by the two high doses. In addition, we induced a co-crystallization between both compounds, determined their fusion points and analyzed the molecules by UV spectroscopy. The data suggested the formation of a supramolecular complex between AFB1 and β-D-glucan.

In vivo evaluation of the antimutagenic and antigenotoxic effects of β-glucan extracted from Saccharomyces cerevisiae in acute treatment with multiple doses

Ample evidence suggests that cancer is triggered by mutagenic damage and diets or supplements capable of reducing such incidences can be related to the prevention of neoplasy development or to an improvement in life quality of patients who undergo chemotherapy. This research aimed to evaluate the antimutagenic and antigenotoxic activity of β-glucan. We set up 8 experimental groups: control (Group 1), cyclophosphamide (Group 2), Groups 3–5 to assess the effect of β-glucan administration, and Groups 6–8 to evaluate the association between cyclophosphamide and β-glucan. The intraperitonial concentrations of β-glucan used were 100, 150 and 200 mg/kg. Micronucleus and comet assays showed that within the first week of treatment β-glucan presented a damage reduction rate between 100–62.04% and 94.34–59.52% for mutagenic and genotoxic damages, respectively. This activity decreased as the treatment was extended. During the sixth week of treatment antimutagenicity rates were reduced to 59.51–39.83% and antigenotoxicity was not effective. This leads to the conclusion that the efficacy of β-glucan in preventing DNA damage is limited when treatment is extended, and that its use as a chemotherapeutic adjuvant need to be better clarified.

Effects of β-glucan polysaccharide revealed by the dominant lethal assay and micronucleus assays, and reproductive performance of male mice exposed to cyclophosphamide

β-glucan is a well-known polysaccharide for its chemopreventive effect. This study aimed to evaluate the chemopreventive ability of β-glucan in somatic and germ cells through the dominant lethal and micronucleus assays, and its influence on the reproductive performance of male mice exposed to cyclophosphamide. The results indicate that β-glucan is capable of preventing changes in DNA in both germ cells and somatic ones. Changes in germ cells were evaluated by the dominant lethal assay and showed damage reduction percentages of 46.46% and 43.79% for the doses of 100 and 150 mg/kg. For the somatic changes, evaluated by micronucleus assay in peripheral blood cells in the first week of treatment, damage reduction percentages from 80.63–116.32% were found. In the fifth and sixth weeks, the percentage ranged from 10.20–52.54% and −0.95–62.35%, respectively. Besides the chemopreventive efficiency it appears that the β-glucan, when combined with cyclophosphamide, is able to improve the reproductive performance of males verified by the significant reduction in rates of post-implantation losses and reabsorption in the mating of nulliparous females with males treated with cyclophosphamide.

Effects of β-glucan extracted from Agaricus blazei on the expression of ERCC5, CASP9, and CYP1A1 genes and metabolic profile in HepG2 cells

The polysaccharide β-glucan has biological properties that stimulate the immune system and can prevent chronic pathologies, including cancer. It has been shown to prevent damage to DNA caused by the chemical and physical agents to which humans are exposed. However, the mechanism of β-glucan remains poorly understood. The objective of the present study was to verify the protective effect of β-glucan on the expression of the genes ERCC5 (involved in excision repair of DNA damage), CASP9 (involved in apoptosis), and CYP1A1 (involved in the metabolism of xenobiotics) using real-time polymerase chain reaction and perform metabolic profile measurements on the HepG2 cells. Cells were exposed to only benzo[a]pyrene (B[a]P), β-glucan, or a combination of B[a]P with β-glucan. The results demonstrated that 50 µg/mL β-glucan significantly repressed the expression of the ERCC5 gene when compared with the untreated control cells in these conditions. No change was found in the CASP9 transcript level. However, the CYP1A1 gene expression was also induced by HepG2 cells exposed to B[a]P only or in association with β-glucan, showing its effective protector against damage caused by B[a]P, while HepG2 cells exposed to only β-glucan did not show CYP1A1 modulation. The metabolic profiles showed moderate bioenergetic metabolism with an increase in the metabolites involved in bioenergetic metabolism (alanine, glutamate, creatine and phosphocholine) in cells treated with β-glucan and to a lesser extent treated with B[a]P. Thus, these results demonstrate that the chemopreventive activity of β-glucan may modulate bioenergetic metabolism and gene expression.

β-Glucans are involved in immune-modulation of THP-1 macrophages

SCOPE

We aimed to examine different immunological aspects of β-glucans derived from different food sources (oat, barley and shiitake) on phorbol myristate acetate (PMA)-differentiated THP-1 macrophages. Commercially purified barley β-glucan (commercial BG) and lentinan were included to compare β-glucans from the same origin but different degree of purity and processing.

METHODS AND RESULTS

Chemical composition and molecular weight distribution of β-glucan samples were determined. Inflammation-related gene expression kinetics (IL-1β, IL-8, nuclear factor kappa B [NF-κB] and IL-10) after 3, 6 and 24 h of stimulation with 100 μg/mL β-glucan were investigated. All tested β-glucans mildly upregulated the observed inflammation-related genes with differential gene expression patterns. Similar gene expression kinetics, but different fold induction values, was found for the crude β-glucan extracts and their corresponding commercial forms. Pre-incubation of THP-1 macrophages with β-glucans prior to lipopolysaccharide (LPS) exposure decreased the induction of inflammation-related genes compared to LPS treatment. No production of nitric oxide (NO) and hydrogen peroxide (H₂O₂) was detected in β-glucan stimulated THP-1 macrophages. Phagocytic activity was not different after stimulation by β-glucan samples.

CONCLUSION

Based on these in vitro analyses, it can be concluded that the analysed β-glucans have varying levels of immunomodulating properties, which are likely related to structure, molecular weight and compositional characteristic of β-glucan.

Agaricus subrufescens: A review

Medicinal mushrooms have currently become a hot issue due to their various therapeutic properties. Of these, Agaricus subrufescens, also known as the "almond mushroom", has long been valued by many societies (i.e., Brazil, China, France, and USA). Since its discovery in 1893, this mushroom has been cultivated throughout the world, especially in Brazil where several strains of A. subrufescens have been developed and used as health food and alternative medicine. This article presents up-to-date information on this mushroom including its taxonomy and health promoting benefits. Medicinal properties of A. subrufescens are emphasized in several studies which are reviewed here. In addition, safety issues concerning the use of this fungus will be discussed.

Evaluating the possible genotoxic, mutagenic and tumor cell proliferation-inhibition effects of a non-anticoagulant, but antithrombotic algal heterofucan

Fucan is a term used to denominate a family of sulfated polysaccharides rich in L-fucose. They are extracted mainly from brown seaweeds and echinoderms. The brown seaweed Spatoglossum schröederi (Dictyotaceae) synthesizes three heterofucans named A, B and C. Our research group purified a non-anticoagulant heterofucan (fucan A) which displays antithrombotic activity in vivo. However, its in vitro toxicity has yet to be determined. This work presents the evaluation of the potential cytotoxicity, mutagenicity and genotoxicity of this fucan. After 48 h incubation fucan A cytotoxicity was determinate using MTT assay. Tumor-cell (HeLa, PC3, PANC, HL60) proliferation was inhibited 2.0-43.7%; at 0.05-1 mg ml⁻¹ of the heterofucan, the 3T3 non-tumor cell line proliferation was also inhibited (3.3-22.0%). On the other hand, the CHO tumorigenic and RAW non-tumor cell lines proliferation were not affected by this molecule (0.05-1 mg ml⁻¹). We observed no mutagenic activity in Salmonella reversion assay when bacterial strains TA97a, TA98, TA100 and TA102 (with and without S9) were used.Comet assay showed that fucan A had no genotoxic effect (from 20 to 1000 mg ml⁻¹) on CHO cells. In conclusion, this study indicates that the S. schröederi fucan A was not found to be genotoxic or mutagenic compound; thus it could be used in new antithrombotic drug development.

Amelioration of streptozotocin-induced diabetes by Agrocybe chaxingu polysaccharide

The aim of this study was to investigate the preventive effect of Agrocybe chaxingu polysaccharide on streptozocin (STZ)-induced pancreatic beta-cells destruction. Agrocybe chaxingu polysaccharide markedly reduced nitric oxide (NO) production and iNOS expression levels in RINm5F cells in a dose-dependent manner. In addition, Agrocybe chaxingu polysaccharide significantly inhibited iNOS expression and blood glucose levels in STZ-induced diabetic mice. Moreover, immunohistochemical analysis revealed that it enhanced pancreatic beta-cells resistance to destruction by STZ. These results suggest that Agrocybe chaxingu polysaccharide may have value as a therapeutic agent against diabetes mellitus.

Investigation on the protective effect of α-mannan against the DNA damage induced by aflatoxin B₁in mouse hepatocytes

Aflatoxin B(1) is a contaminant of agricultural and dairy products that can be related to mutagenic and carcinogenic effects. In this report we explore the capacity of alpha-mannan (Man) to reduce the DNA damage induced by AFB(1) in mouse hepatocytes. For this purpose we applied the comet assay to groups of animals which were first administered Man (100, 400 and 700 mg/kg, respectively) and 20 min later 1.0 mg/kg of AFB(1). Liver cells were obtained at 4, 10, and 16 h after the chemical administration and examined. The results showed no protection of the damage induced by AFB(1) with the low dose of the polysaccharide, but they did reveal antigenotoxic activity exerted by the two high doses. In addition, we induced a co-crystallization between both compounds, determined their fusion points and analyzed the molecules by UV spectroscopy. The obtained data suggested the formation of a supramolecular complex between AFB(1) and Man.