Protective effects of β-glucan extracted from Agaricus brasiliensis against chemically induced DNA damage in human lymphocytes

Agaricus blazei Polysaccharide Alleviates DSS-Induced Colitis in Mice by Modulating Intestinal Barrier and Remodeling Metabolism

Ulcerative colitis (UC) is a chronic noninfectious intestinal disease that severely affects patients' quality of life. Agaricus blazei Murrill polysaccharide (ABP) is an effective active ingredient extracted from Agaricus blazei Murrill (ABM). It has good efficacy in inhibiting tumor cell growth, lowering blood pressure, and improving atherosclerosis. However, its effect on colitis is unclear. The aim of this study was to analyze the protective effects and potential mechanisms of ABP against dextran sulfate sodium (DSS)-induced acute colitis in mice. The results showed that dietary supplementation with ABP significantly alleviated DSS-induced colitis symptoms, inflammatory responses, and oxidative stress. Meanwhile, ABP intervention was able to maintain the integrity of the intestinal mechanical barrier by promoting the expression of ZO-1 and Occludin tight junction proteins and facilitating mucus secretion. Moreover, 16S rRNA sequencing results suggested that ABP intervention was able to alleviate DSS-induced gut microbiota disruption, and nontargeted metabolomics results indicated that ABP was able to remodel metabolism. In conclusion, these results demonstrate that dietary supplementation with ABP alleviated DSS-induced acute colitis by maintaining intestinal barrier integrity and remodeling metabolism. These results improve our understanding of ABP function and provide a theoretical basis for the use of dietary supplementation with ABP for the prevention of ulcerative colitis.

Genetic engineering of complex feed enzymes into barley seed for direct utilization in animal feedstuff

Currently, feed enzymes are primarily obtained through fermentation of fungi, bacteria, and other microorganisms. Although the manufacturing technology for feed enzymes has evolved rapidly, the activities of these enzymes decline during the granulating process and the cost of application has increased over time. An alternative approach is the use of genetically modified plants containing complex feed enzymes for direct utilization in animal feedstuff. We co-expressed three commonly used feed enzymes (phytase, β-glucanase, and xylanase) in barley seeds using the Agrobacterium-mediated transformation method and generated a new barley germplasm. The results showed that these enzymes were stable and had no effect on the development of the seeds. Supplementation of the basal diet of laying hens with only 8% of enzyme-containing seeds decreased the quantities of indigestible carbohydrates, improved the availability of phosphorus, and reduced the impact of animal production on the environment to an extent similar to directly adding exogenous enzymes to the feed. Feeding enzyme-containing seeds to layers significantly increased the strength of the eggshell and the weight of the eggs by 10.0%-11.3% and 5.6%-7.7% respectively. The intestinal microbiota obtained from layers fed with enzyme-containing seeds was altered compared to controls and was dominated by Alispes and Rikenella. Therefore, the transgenic barley seeds produced in this study can be used as an ideal feedstuff for use in animal feed.

Evaluation of the genotoxic and antigenotoxic effects of exopolysaccharide pullulan in human lymphocytes in vitro

Pullulan is a biocompatible and water-soluble exo-polysaccharide produced by primary strains of the fungus Aureobasidium pullulans. It is frequently used in the pharmaceutical and food industries. In this study, possible cytotoxic effect of pullulan was assessed using the MTT assay in the human breast cancer (MCF-7) cell line. Micronucleus (MN), micronucleus-FISH (MN-FISH), random amplified polymorphic DNA (RAPD-PCR), and comet assays were used to investigate genotoxic and antigenotoxic effects of pullulan against mitomycin C (MMC) (at MN assay) and hydrogen peroxide (at comet assay) in human lymphocytes. Antigenotoxicity was determined using two different applications: 1 h pretreatment and simultaneous treatment. In the MTT assay, pullulan significantly reduced the cell viability at 15.6-2000 μg/mL compared to the control. No significant alterations in MN rates were found in human lymphocytes treated with different concentrations of pullulan compared to the control. In contrast, co-treatment of pullulan and MMC decreased the frequency of MN in almost all the treatment concentrations and durations compared to the MMC. No significant change was observed in the frequency of the centromere-positive C + or negative C- MNi compared to the positive control. In comet assay, pullulan did not affect comet tail intensity compared to the negative control. On the contrary, pullulan in combination with H₂O₂ significantly decreased tail intensity at almost all the concentrations compared to the positive control. The changes occurring in RAPD-PCR profiles following pullulan treatments included an increase or decrease in band intensity and gain or loss of bands. These results indicate that exopolysaccharide Pullulan is not genotoxic; moreover, it possesses a protective effect against MMC and H₂O₂ induced genotoxicity. In breast cancer cells, pullulan induced cytotoxic/anti-proliferative effect.

Subcritical Water Extracts from Agaricus blazei Murrill's Mycelium Inhibit the Expression of Immune Checkpoint Molecules and Axl Receptor

Agaricus blazei Murrill or Himematsutake is an edible and medicinal mushroom. Agaricus blazei Murrill’s fruiting body extracts have anticancer properties, although the mechanism is unknown. Basic or organic solvents, which are hazardous for human health, are generally used to prepare Agaricus blazei Murrill’s extracts. The inhibition of immune checkpoint molecules and Axl receptor is an effective therapy in cancer. This study assessed whether subcritical water extracts of the Agaricus blazei Murrill’s fruiting body or mycelium affect the expression of Axl and immune checkpoint molecules in lung cancer cells. We used A549 cells and mouse bone marrow-derived dendritic cells in the experiments. We prepared subcritical water extracts from the Agaricus blazei Murrill’s fruiting body or mycelium. The subcritical water extracts from the Agaricus blazei Murrill’s fruiting body or mycelium significantly inhibited the expression of immune checkpoint molecules and Axl compared to saline-treated cells. Additionally, the hot water extract, subcritical water extract, and the hot water extraction residue subcritical water extract from the Agaricus blazei Murrill’s mycelium significantly enhanced the expression of maturation markers in dendritic cells. These observations suggest that the subcritical water extract from Agaricus blazei Murrill’s mycelium is a promising therapeutic tool for stimulating the immune response in cancer.

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.

Optimization of Liquid Culture Condition of a Novel Fungus Hygrophoropsis sp. and Antioxidant Activity of Extracts

To evaluate pharmacological activities of a novel fungus Hygrophoropsis sp., the influence of aeration rate on the production of mycelial biomass, exopolysaccharides (EPS), and intrapolysaccharides (IPS) in the fungus Hygrophoropsis sp. was investigated. And the water extracts of cultured Hygrophoropsis sp. mycelia and the fermentation broth were analyzed for their antioxidation activity by using four different assay methods such as hydroxyl radical scavenging, superoxide radical scavenging, hydrogen peroxide scavenging, and reducing power. The Hygrophoropsis sp. was cultivated under various aeration rates in a 7 l bioreactor. The highest mycelial biomass (3.98 mg/mL) and IPS production (19.63 mg/g) were obtained at aeration rate 4.5 v.v.m. The results showed that Hygrophoropsis sp., in general, possesses a strong antioxidation activity in all assays tested. The deproteinized extracts had stronger antioxidation activity as compared to the un-deproteinized extracts by using superoxide radical scavenging, hydrogen peroxide scavenging, and reducing power. Besides, the un-deproteinized extracts had stronger antioxidation activity as compared to the deproteinized extracts by using hydroxyl radical scavenging. Thus, the polysaccharide extractions from the Hygrophoropsis sp. studied have antioxidant activities in vitro, which may be a good source of natural antioxidants or further investigation as potential natural antioxidants.

Cereal B-Glucans: The Impact of Processing and How It Affects Physiological Responses

Cereal β-glucans are dietary fibres primarily found in oats and barley, and have several positive effects on health, including lowering the postprandial glucose response and the improvement of blood cholesterol levels. Cereal β-glucans have a specific combination of β-(1→4) and β-(1→3) linkages into linear long-chain polysaccharides of high molecular weight. Due to their particular structure, cereal β-glucans generate viscosity within the intestinal tract, which is thought to be the main mechanism of action responsible for their positive health effects. However, cereal grains are rarely consumed raw; at least one cooking step is generally required before they can be safely eaten. Cooking and processing methods more generally will modify the physicochemical characteristics of β-glucans, such as molecular weight, extractability and the resulting viscosity. Therefore, the health impact of β-glucans will depend not only on the dose administered, but also on the ways they are processed or converted into food products. This review aims at summarizing the different parameters that can affect β-glucans efficacy to improve glucose and lipid metabolism in humans.

Protective effect of β-D-glucan and glutamine on the genomic instability induced by Cytarabine/Ara-C in BALB/c mice

Prophylactic antibiotics and growth promoters have been substituted, mainly for livestock, by immunomodulators and intestinal health promoters - such as β-D-glucans and glutamine. The aim of this study was to verify the beneficial effects of β-D-glucans and glutamine against Cytarabine/Ara-C, evaluating the DNA damage in leukocytes, the leukogram, and the mitotic index of intestinal crypts cells. Balb/C mice received treatment with β-D-glucan (80 mg/Kg), glutamine (150 mg/Kg), or both, for 21 days. On the last two days of this period, Ara-C was administered (1.8 mg/animal) by intraperitoneal injection every 12 h. The animals submitted to the treatment with Ara-C presented the highest genotoxic index, a significant leukopenia, and a decrease in the mitotic index of the intestinal crypts cells. Treatment with β-D-glucan protected the leukocytes against DNA fragmentation induced by Ara-C. Glutamine alone promoted maintenance of the mitotic index and, in association with β-Dglucan, reduced leukopenia. Thus, the use of β-D-glucan and glutamine proved to be beneficial to intestinal tropism. This can happen once the damage to the genetic material, prevented by the treatments with β-D-glucan and glutamine, can result in genotoxicity. Not only this, but it might be capable of turning into a mutagenesis, with consequential physiopathological alterations.

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.

Structure elucidation and antitumor activity of a new polysaccharide from Maerkang Tricholoma matsutake

A new heteropolysaccharide was isolated from the fruiting bodies of Tricholoma matsutake which had a molecular weight of 12078 Da. The results of structural features analysis showed that T. matsutake polysaccharide, here named TMP-B, was mainly composed of α - D - glucose and α - D - galactose which ratios were 7:2 and had a backbone of 1, 4 - linked α - D - glucose which branches were mainly composed of two 6 - linked α - D - galactose residue, and the α - D - galactose was 1, 6 - linked. Antitumor activity results showed that heteropolysaccharide TMP-B could inhibit the growth of S180 tumor in vivo and promote the apoptosis of L929 cells in vitro. Immunoregulatory activity results showed that TMP-B could promote the proliferation of macrophages by affecting G0/G1 phase, S phases and G2/M phases and promote cytokines release and gene expression. The result of this study introduced Maerkang T. matsutake as a possible valuable source which helped to exhibit unique antitumor and immunoregulatory properties.

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.

In vitro protective effects of botryosphaeran, a (1→3;1→6)-β-d-glucan, against mutagens in normal and tumor rodent cells

Botryosphaeran (BOT) is an exocellular β-d-glucan (carbohydrate biopolymer) of the (1→3;1→6)-linked type produced by Botryosphaeria rhodina MAMB-05. The cytotoxic, mutagenic, genotoxic, and protective effects of this substance were evaluated in Chinese hamster lung fibroblasts (V79) and rat hepatocarcinoma cells (HTC) by the micronucleus test (MN) and the comet assay. BOT was not genotoxic in either cell line; it decreased the clastogenic effects of doxorubicin, H₂O₂, and benzo[a]pyrene. These results indicate that BOT may have potential as a therapeutic agent.

Structure and antioxidant activity of a novel polysaccharide derived from Amanita caesarea

A heteropolysaccharide was isolated from the fruiting bodies of Amanita caesarea using a diethylaminoethyl-cellulose column, Sephacryl S‑300 gel column and Sephadex G‑200 column. The Amanita caesarea polysaccharide was predominantly composed of α-D-glucose and α-D-lyxose at a ratio of 2:1, and it had a molecular weight of 19,329 Da. The structural features of the Amanita caesarea polysaccharide were investigated by a combination of total hydrolysis, methylation analysis, gas chromatography-mass spectrometry, and infrared spectra and nuclear magnetic resonance spectroscopy. The results showed that Amanita caesarea polysaccharide (termed AC‑1) had a backbone of 1,4‑linked α‑D‑glucose and 1,3,6‑linked α‑D‑glucose, with branches of one 1‑linked α‑D‑lyxose residue. The antioxidant activity of AC‑1 was evaluated by two biochemical methods, 2,2-azino-bis diammonium (ABTS+) radical scavenging activity and 1,1-diphenyl-2-picrylhydrazyl (DPPH-) radical scavenging activity. The uncontrolled production of free radicals is involved in various diseases, including cancer, atherosclerosis and degenerative aging processes. The results indicated that the Amanita caesarea polysaccharide exhibits strong antioxidant activity, thus, it may be a useful natural product antioxidant.

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.

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.

Structure elucidation, anticancer and antioxidant activities of a novel polysaccharide from Gomphus clavatus Gray

A novel heteropolysaccharide from the fruiting bodies of Gomphus clavatus Gray was isolated through Sephadex G-200 and DEAE-cellulose columns. The Gomphus clavatus Gray polysaccharide (GCG-1) was mainly composed of β-D-glucosepyranose (β-D-Glu) and α-D-galactopyranose (α-D-Gal) in a ratio of 3:2 and had a molecular weight of ~50,000 Da. The structure of GCG-1 was investigated by a combination of total hydrolysis, gas chromatography-mass spectrometry, methylation analysis, nuclear magnetic resonance spectroscopy and infrared spectra. The results indicated that GCG-1 had a backbone of (1 → 4)-β-D-glucosepyranose residues with branches at O-6 and the branches consisted of two with (1 → 3)-α-D-galactopyranose residue. Antioxidation test in vitro showed that it possessed strong free radical scavenging activity, which may be comparable to vitamin C and butylated hydroxytoluene. GCG-1 also induced the apoptosis of HepG-2 cells and affected the mRNA expression of various housekeeping genes in the HepG-2 cells. The results indicated that Gomphus clavatus Gray may be an ideal sources for antioxidant and anticancer agents.

Immunostimulant Activity of a Novel Polysaccharide Isolated from Lactarius deliciosus (L. ex Fr.) Gray

More and more fungal polysaccharides have been reported to exhibit a variety of biological activities, including antitumor, antioxidant and immunostimulant activity. The non-starch polysaccharides have emerged as an important class of bioactive natural products. In this study, the immune activities of a novel polysaccharide (LDG-A) isolated from Lactarius deliciosus (L. ex Fr.) Gray were investigated at 20, 40 and 80 mg/kg dose levels. The inhibitory rate in mice treated with 80 mg/kg LDG-A can reach 68.422%, being the highest in the three doses, which may be comparable to mannatide. Histology of immune organs showed that the tissues were arranged in more regular and firm pattern, but the tumor tissue arranged looser in LDG-A group than those in control group. Meanwhile, there was no obvious damage to other organs, such as heart, lung, and kidney. The antitumor activity of the LDG-A was usually believed to be a consequence of the stimulation of the cell-mediated immune response because it can significantly promote the lymphocyte and macrophage cells in the dose range of 50-200 μg/ml and 100-400 μg/ml in vitro, respectively. The level of cytokines (IL-6, TNF-α, and NO) of macrophage cells induced by LDG-A treatment was similar to lipopolysaccharides at different concentrations. The expression of all these genes studied (TNF-α, IL-6, and iNOS mRNA) in the untreated macrophage was little, but increased dramatically in a dose-dependent manner in the LDG-A-treated cells. The results obtained in the present study indicated that the purified polysaccharide of L. deliciosus (L. ex Fr.) Gray is a potential source of natural immune-stimulating substances.

Analgesic Activity of a Glucan Polysaccharide Isolated from Agaricus blazei Murill

A water soluble polysaccharide and its selective precipitated fractions (F1, F2, and F3) were isolated from hot water extract of fruiting bodies of Agaricus blazei Murril known as Agaricus brasiliensis to evaluate the analgesic activity of the materials in Swiss mice. The isolated material and its fractions were characterized by two-dimensional COSY and HMQC spectra as β-(1→6)-α-(1→4)-glucan-bound-protein polysaccharide constituted mainly by β-(1→6) glucan. The glucan-protein polysaccharide and its fractions were analyzed in relation to the protein, carbohydrate, and mineral elements contents. The analysis of the glucan-protein complex revealed a total carbohydrate content of 36.95% and protein conjugated content of 17.24%. The mineral elements found in larger proportion were K, Na, Ca, P, and Zn. The analgesic activity bioassay of the β-(1→6)-α-(1→4)-glucan bound-protein polysaccharide and its fractions in Swiss mice indicated a significant effect.

Anti-microorganism, anti-tumor, and immune activities of a novel polysaccharide isolated from Tricholoma matsutake

Background:

Many more fungal polysaccharides have been reported to exhibit a variety of biological activities, including anti-tumor, immunostimulation, anti-oxidation, and so on. The non-starch polysaccharides have emerged as an important class of bioactive natural products.

Objective:

To investigate the anti-microorganism, anti-tumor, and immune activities of a novel polysaccharide (TMP-A) isolated from Tricholoma matsutake.

Materials and Methods:

The anti-microorganism activity of purified polysaccharides (TMP-A) was evaluated by the inhibition zone diameter, the anti-tumor activity was evaluated by the S180 tumor cells that were implanted subcutaneously into the Kunming strain male mice in vivo, and the immune activity was evaluated by lymphocyte proliferation and macrophage stimulation, respectively.

Results:

In this study, the most susceptible bacteria of TMP-A at a concentration of 20 mg/ml was Micrococcus lysodeikticus (inhibition zone diameter 24.38 ± 1.19 mm) and the TMP-A did not show any antifungal activity for the tested stains of the fungi. In addition, the inhibitory rate in mice treated with 80 mg/kg TMP-A could reach 68.422%, being the highest in the three doses, which might be comparable to mannatide. The anti-tumor activity of the TMP-A was usually believed to be a consequence of the stimulation of the cell-mediated immune response, because it could significantly promote the lymphocyte and macrophage cells in the dose range of 50–200 μg/mL and in the dose range of 100 – 400 μg/mL in vitro, respectively.

Discussion and Conclusion:

The results obtained in the present study indicate that the purification polysaccharide of Tricholoma matsutake is a potential source of natural broad-spectrum, anti-microorganism, anti-tumor, and immunomodulation.

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.

Dietary supplementation with Agaricus blazei murill extract prevents diet-induced obesity and insulin resistance in rats

OBJECTIVE

Dietary supplement may potentially help to fight obesity and other metabolic disorders such as insulin-resistance and low-grade inflammation. The present study aimed to test whether supplementation with Agaricus blazei murill (ABM) extract could have an effect on diet-induced obesity in rats.

DESIGN AND METHODS

Wistar rats were fed with control diet (CD) or high-fat diet (HF) and either with or without supplemented ABM for 20 weeks.

RESULTS

HF diet-induced body weight gain and increased fat mass compared to CD. In addition HF-fed rats developed hyperleptinemia and insulinemia as well as insulin resistance and glucose intolerance. In HF-fed rats, visceral adipose tissue also expressed biomarkers of inflammation. ABM supplementation in HF rats had a protective effect against body weight gain and all study related disorders. This was not due to decreased food intake which remained significantly higher in HF rats whether supplemented with ABM or not compared to control. There was also no change in gut microbiota composition in HF supplemented with ABM. Interestingly, ABM supplementation induced an increase in both energy expenditure and locomotor activity which could partially explain its protective effect against diet-induced obesity. In addition a decrease in pancreatic lipase activity is also observed in jejunum of ABM-treated rats suggesting a decrease in lipid absorption.

CONCLUSIONS

Taken together these data highlight a role for ABM to prevent body weight gain and related disorders in peripheral targets independently of effect in food intake in central nervous system.

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.

Preservation of Agaricus subrufescens strains at low temperature by using cultures on sorghum grains

BACKGROUND

One of the main problems for the preservation of genetics resources of Agaricus subrufescens is to maintain the viability of the strains because the mycelium is very sensitive to cooling and therefore it ages rapidly.

AIMS

Evaluate the viability of A. subrufescens strains stored as cultures on sorghum grain (spawn) at different temperatures.

METHODS

Eighteen strains of A. subrufescens and three strains of Agaricus bisporus were studied. Spawn's viability was evaluated under the following conditions: (1) control at 25°C (C), (2) cooling to 4°C (R) and (3) freezing in liquid nitrogen at -196°C (LN). Samples were recovered from week 4 every 2 weeks until week 12 and week 24 in C and R, whereas in LN samples were recovered at 4, 12 and 24 weeks. Viability was evaluated in 50 seeds, by strain and condition, recovering the mycelium in Petri dishes with potato dextrose agar medium (PDA). Mycelium growth was also evaluated on PDA after 14 days of recovery.

RESULTS

Most strains showed 100% viability and they were recovered usually in 1 day. In LN the viability ranged between 84 and 100% depending on the strain, but in some cases recovery took more than 10 days. Mycelial growth decreased gradually over time and although the results show significant differences between treatments C and R, the decline is associated with ageing of the mycelium rather than the treatment itself.

CONCLUSIONS

Culture on sorghum grain and storage at low temperature is an interesting way to preserve genetic resources of A. subrufescens.

Preparation, characterization, and biological properties of β-glucans

β-Glucans are soluble fibers with physiological functions, such as, interference with absorption of sugars and reduction of serum lipid levels. β-glucans are found in different species, such as, Rhynchelytrum repens, Lentinus edodes, Grifola frondosa, Tremella mesenterica, Tremella aurantia, Zea may, Agaricus blazei, Phellinus baummi, Saccharomyces cerevisae (yeast), and Agaricus blazei murell (mushroom). Analysis of the fractions reveals the presence of arabinose, glucose, xylose, and traces of rhamnose and galactose. The presence of β-glucan in these fractions is confirmed by hydrolyzing the polymers with endo-β-glucanase from Bacillus subtilis, followed by high-performance liquid chromatography (HPLC) analysis of the characteristic oligosaccharides produced. The 4 M KOH fractions from different tissues are subjected to gel permeation chromatography on Sepharose 4B, with separation of polysaccharides, with different degrees of polymerization, the highest molecular mass (above 2000 kDa) being found in young leaves. The molecular mass of the leaf blade polymers is similar (250 kDa) to that of the maize coleoptiles β-glucan used for comparison. The 4 M KOH fraction injected into rats with streptozotocin-induced diabetes has shown hypoglycemic activity, reducing blood sugar to normal levels for approximately 24 hours. This performance is better than that obtained with pure β-glucan from barley, which decreases blood sugar levels for about four hours. These results suggest that the activity of β-glucans is responsible for the use of this plant extract as a hypoglycemic drug in folk medicine.

Effect of AndoSan™ on expression of adhesion molecules and production of reactive oxygen species in human monocytes and granulocytes in vivo

BACKGROUND

Oral intake (60 ml daily) over 12 days in eight healthy volunteers of an immunostimulatory extract based on the medicinal mushroom Agaricus blazei Murill (AbM (AndoSan™)), reduced the monocyte and granulocyte release of mainly proinflammatory cytokines in vivo, suggesting an anti-inflammatory effect. In this foremost in vivo study, the aim was to examine the effect of such AndoSan™ consumption on the expression of adhesion molecules CD11b, CD11c and CD62L and production of reactive oxygen species (ROS) in leukocytes.

METHODOLOGY/PRINCIPAL FINDINGS

As shown by flow cytometry, there was a significant increase of CD62L expression on monocytes and granulocytes from before (day 0) compared with 12 days after daily AndoSan™ consumption. However, only minor alterations and no clear trend in the expression of CD11b and CD11c were detected. Intracellular ROS (mainly superoxide ion) were significantly reduced in these cells from days 0 to 12.

CONCLUSIONS/SIGNIFICANCE

These results support that oral intake of AndoSan™ exhibits an anti-inflammatory effect in humans in vivo.

Pleurotus tuber-regium Polysaccharides Attenuate Hyperglycemia and Oxidative Stress in Experimental Diabetic Rats

Pleurotus tuber-regium contains polysaccharides that are responsible for pharmacological actions, and medicinal effects of these polysaccharides have not yet been studied in diabetic rats. We examined the antidiabetic, antihyperlipidemic, and antioxidant properties of P. tuber-regium polysaccharides in experimental diabetic rats. Forty rats were equally assigned as diabetic high-fat (DHF) diet and polysaccharides treated DHF groups (DHF+1P, DHF+2P, and DHF+3P, 20 mg/kg bodyweight/8-week). Diabetes was induced by chronic low-dose streptozotocin injections and a high-fat diet to mimic type 2 diabetes. Polysaccharides (1P, 2P, and 3P) were extracted from three different strains of P. tuber-regium. Fasting blood glucose and glycosylated hemoglobin (HbA1c) levels substantially decreased, while serum insulin levels were restored by polysaccharides treatment compared to DHF. Furthermore, plasma total cholesterol, triglycerides, and low-density lipoprotein levels were significantly (P < 0.01) lower in polysaccharide groups. High-density lipoprotein levels were attenuated with polysaccharides against diabetes condition. Polysaccharides inhibited (P < 0.01) the lipid peroxidation index (malondialdehyde), and restored superoxide dismutase and glutathione peroxidase activities in the liver of diabetic rats. The antihyperglycemic property of polysaccharides perhaps boosts the antioxidant system that attenuates oxidative stress. We emphasize that P. tuber-regium polysaccharides can be considered as an alternative medicine to treat hyperglycemia and oxidative stress in diabetic rats.

Anticlastogenic effect of β-glucan, extracted from Saccharomyces cerevisiae, on cultured cells exposed to ultraviolet radiation

β-glucan is an important polysaccharide due to its medicinal properties of stimulating the immune system and preventing chronic diseases such as cancer. The aim of the present study was to determine the anticlastogenic effect of β-glucan in cells exposed to ultraviolet radiation (UV). Chromosome aberration assay was performed in drug-metabolizing cells (HTC) and non drug-metabolizing cells (CHO-K1 and repair-deficient CHO-xrs5), using different treatment protocols. Continuous treatment (UV + β-glucan) was not effective in reducing the DNA damage only in CHO-xrs5 cells. However, the pre-treatment protocol (β-glucan before UV exposition) was effective in reducing DNA damage only in CHO-K1 cells. In post-treatment (β-glucan after UV exposition) did not show significative anticlastogenic effects, although there was a tendency toward prevention. The data suggest that β-glucan has more than one action mechanism, being capable of exerting desmutagenic as well as bio-antimutagenic action. The findings also suggest that the presence of the xenobiotic metabolizing system can reduce the chemopreventive capacity of β-glucan. Therefore, these results indicate that β-glucan from Saccharomyces cerevisiae can be used in the prevention and/or reduction of DNA damage.

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.

Carboxymethyl chitin-glucan (CM-CG) protects human HepG2 and HeLa cells against oxidative DNA lesions and stimulates DNA repair of lesions induced by alkylating agents

A large number of functional foods, including those that contain β-d-glucans, have been shown to prevent human DNA against genotoxic effects and associated development of cancer and other chronic diseases. In this paper, carboxymethyl chitin-glucan (CM-CG) isolated from Aspergillus niger was investigated from two standpoints: (1) DNA-protective effects against oxidative DNA damage induced by H(2)O(2) and alkylating DNA damage induced by MMS and MNNG, and (2) a potential effect on rejoining of MMS- and MNNG-induced single strand DNA breaks. The results obtained by the comet assay in human cells cultured in vitro showed that CM-CG reduced significantly the level of oxidative DNA lesions induced by H(2)O(2) but did not change the level of alkylating DNA lesions induced by MMS or MNNG. On the other side, the efficiency of DNA-rejoining of single strand DNA breaks induced by MMS and MNNG was significantly higher in HepG2 cells pre-treated with CM-CG. The antioxidative activity of carboxymethyl chitin-glucan was confirmed by the DPPH assay.

Purinergic effects of a hydroalcoholic Agaricus brasiliensis (A. blazei) extract on liver functions

The effects of a hydroalcoholic extract of Agaricus brasiliensis (A. blazei) on functional parameters in the perfused rat liver were examined with emphasis on its content of nucleotides and nucleosides. Several nucleosides and nucleotides were identified in the A. brasiliensis extract, which was active on several liver functions. A significant part of the effects is the result of the purinergic action of nucleosides and nucleotides: pressure increment, glycogenolysis stimulation, transient inhibition of oxygen consumption, and redox state changes. Other phenomena such as the stimulation of gluconeogenesis, ureogenesis, and oxygen consumption are more likely consequences of the metabolic transformation of substrates contained within the extract, especially amino acids. It seems apparent that consumption of A. brasiliensis represents not only the ingestion of metabolic precursors but also the ingestion of substances that, even at low concentrations, can exert important signaling functions in the liver as well as in the organism as a whole.

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.

Protective effects of beta-glucan extracted from barley against benzo[a]pyrene-induced DNA damage in hepatic cell HepG2

The aim of the present study was to assess the genotoxic and antigenotoxic effect of beta-glucan (BG) extracted from barley. The genotoxicity of BG was tested in the single-cell gel electrophoresis assays (SCGE)/HepG2 test system. Moreover, the protective effects of BG against the genotoxicity of B[a]P were studied to delineate its mechanism of antigenotoxicity using four different treatment protocols - pre-treatment, simultaneous simple, simultaneous with pre-incubation, and post-treatment. The results showed that the compound itself was devoid of mutagenic activity at the three lower concentrations studied (1, 5, and 25microg/mL); however, genotoxic and cytotoxic effects were seen at 100 and 200microg/mL, respectively. In combination experiments with B[a]P, pronounced inhibition of DNA migration in the SCGE assay was observed in the two simultaneous treatments, and a smaller reduction was observed in the two other treatments. Thus, the data suggest that BG acts through binding to the genotoxic compound or capturing free radicals produced during its activation. However, the protective effects observed with pre-treatment and post-treatment suggest that the BG may be modulating cell metabolism.

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

The mushroom Agaricus blazei is studied for its nutraceutical potential and as a medicinal supplement. The aim of the present study was to investigate the chemoprotective effect of beta-glucan extracted from the mushroom A. blazei against DNA damage induced by benzo[a]pyrene (B[a]P), using the comet assay (genotoxicity) and micronucleus assay with cytokinesis block (mutagenicity) in a human hepatoma cell line (HepG2). To elucidate the possible beta-glucan mechanism of action, desmutagenesis or bioantimutagenesis types, three treatment protocols were tested: simultaneous, pre-treatment, and presimultaneous. The results showed that beta-glucan does not exert genotoxic or mutagenic effect, but that it does protect against DNA damage caused by B[a]P in every protocol tested. The data suggest that beta-glucan acts through binding to B[a]P or the capture of free radicals produced during its activation. On the other hand, the pre-treatment results also suggest the possibility that beta-glucan modulates cell metabolism.