Relationship between selenium accumulation and mycelial cell composition in Lentinula edodes (Berk.) cultures

Effect of Supplementation with the Combination of Se-Enriched Lentinula edodes Mycelium, Exogenous Enzymes, Acidifiers, Sodium Butyrate and Silicon Dioxide Nanoparticle Feed Additives on Selected Parameters in Calves

During the initial months of calves’ lives, the young animals are exposed to bacterial and viral infections, and during this period, crucial physiological changes take place in their organisms. Offering calves feed additives that will have a beneficial influence on their organisms and improve their growth while reducing the morbidity rate is the optimal task of feeding. This is the first study to investigate the effect of experimental supplementation for calves with the combination of two feed additives—one containing Lentinula edodes enriched with selenium (Se), and the second containing pancreatic-like enzymes, fat-coated organic acids, sodium butyrate, and silicon dioxide nanoparticles—on the serum Se concentration, selected immune parameters, and the average daily gains in the calves. During the study, the serum Se concentration was examined by means of inductively coupled plasma mass spectrometry, and the immunoglobulin and cytokine concentrations with ELISA assays. The white blood cell (WBC) count with leukocyte differentiation was examined with the use of a hematological analyzer, and the percentages of subpopulations of T lymphocytes and monocytes, phagocytic activity, and oxidative burst of monocytes and granulocytes with the use of a flow cytometer. The average daily gains of the calves were also evaluated. In summary, the supplementation of the experimental calves with the combination of two feed additives resulted in significantly higher serum Se concentrations, and the immune systems of the calves were not suppressed while the examined feed additives were being delivered. Although not statistically significant, some positive effects on the calves were seen: a tendency towards the improvement of some of the immune parameters evaluated, and a tendency for higher average daily gains in the calves.

Selenium-Containing Exopolysaccharides Isolated from the Culture Medium of Lentinula edodes: Structure and Biological Activity

In continuation of our research on the influence of selenium incorporation on the biosynthesis, structure, and immunomodulatory and antioxidant activities of polysaccharides of fungal origin, we have isolated from a post-culture medium of Lentinula edodes a selenium (Se)-containing exopolysaccharide fraction composed mainly of a highly branched 1-6-α-mannoprotein of molecular weight 4.5 × 10⁶ Da, with 15% protein component. The structure of this fraction resembled mannoproteins isolated from yeast and other mushroom cultures, but it was characterized by a significantly higher molecular weight. X-ray absorption fine structure spectral analysis in the near edge region (XANES) suggested that selenium in the Se-exopolysaccharide structure was present mainly at the IV oxidation state. The simulation analysis in the EXAFS region suggested the presence of two oxygen atoms in the region surrounding the selenium. On the grounds of our previous studies, we hypothesized that selenium-enriched exopolysaccharides would possess higher biological activity than the non-Se-enriched reference fraction. To perform structure-activity studies, we conducted the same tests of biological activity as for previously obtained mycelial Se-polyglucans. The Se-enriched exopolysaccharide fraction significantly enhanced cell viability when incubated with normal (human umbilical vein endothelial cells (HUVEC)) cells (but this effect was absent for malignant human cervical HeLa cells) and this fraction also protected the cells from oxidative stress conditions. The results of tests on the proliferation of human peripheral blood mononuclear cells suggested a selective immunosuppressive activity, like previously tested Se-polyglucans isolated from L. edodes mycelium. The Se-exopolysaccharide fraction, in concentrations of 10-100 µg/mL, inhibited human T lymphocyte proliferation induced by mitogens, without significant effects on B lymphocytes. As with previously obtained Se-polyglucans, in the currently tested Se-polymannans, the selenium content increased the biological activity. However, the activity of selenium exopolysaccharides in all tests was significantly lower than that of previously tested mycelial isolates, most likely due to a different mode of selenium binding and its higher degree of oxidation.

Selenium and the health status, production results, and product quality in poultry

A Selenium (Se) is an element belonging to the nonmetallic group. It was first discovered in 1817 by J.J. Berzelius. Until the 1950s, it was considered to be toxic to animals. However, with increasing research conducted on laboratory animals, it is now clear that Se is necessary for the proper functioning of both plants and animals. Recent studies indicate that Se is necessary for the proper functioning of metabolic pathways in animals. It was evidenced that Se is a component of about 100 proteins involved in the immune system, antioxidant homeostasis, or release of an inflammatory mediator. Therefore, it is of key interest to find the appropriate dosage for the supplementation of Se in the diet of farm animals and thereby eliminate physiological disorders in the body associated with Se imbalance. In this study, we present a literature review on the importance and appropriate dosage of Se in the diet of poultry concerning their health status, production results, and the quality of animal-origin products.

Influence of Selenium Biofortification on the Growth and Bioactive Metabolites of Ganoderma lucidum

Selenium biofortification of edible and medicinal mushrooms is an effective way to produce selenium-enriched food supplements. Ganoderma lucidum is the typical one with excellent biological activity. This study investigated G. lucidum growth and bioactive metabolites alterations during liquid culture with different concentrations of selenite. Low selenium levels did not affect growth and mycelia morphology, whereas high selenium levels negatively influenced growth, dramatically decreased biomass, caused nucleic acid and protein leakage, damaged cell walls and membranes, and resulted in indicators such as degraded cells, a red color, and an unpleasant odor. Through headspace-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) analysis, ten volatile Se compounds were identified in G. lucidum with 200 ppm selenite, which led to an odor change, whereas only three with 50 ppm selenite. SeMet was the major selenoamino acid in the 50 ppm selenite group by high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS), but more MeSeCys was produced with 200 ppm selenite. Polysaccharide yields were promoted and inhibited with 50 and 200 ppm selenite, respectively. These results provide comprehensive insights into the effects of selenite on G. lucidum in liquid culture and are beneficial for functional selenium-enriched mushroom production and improving nutritive values.

Selenium-Containing Polysaccharides—Structural Diversity, Biosynthesis, Chemical Modifications and Biological Activity

Selenosugars are a group of sugar derivatives of great structural diversity (e.g., molar masses, selenium oxidation state, and selenium binding), obtained as a result of biosynthesis, chemical modification of natural compounds, or chemical synthesis. Seleno-monosaccharides and disaccharides are known to be non-toxic products of the natural metabolism of selenium compounds in mammals. In the case of the selenium-containing polysaccharides of natural origin, their formation is also postulated as a form of detoxification of excess selenium in microorganisms, mushroom, and plants. The valency of selenium in selenium-containing polysaccharides can be: 0 (encapsulated nano-selenium), IV (selenites of polysaccharides), or II (selenoglycosides or selenium built into the sugar ring to replace oxygen). The great interest in Se-polysaccharides results from the expected synergy between selenium and polysaccharides. Several plant- and mushroom-derived polysaccharides are potent macromolecules with antitumor, immunomodulatory, antioxidant, and other biological properties. Selenium, a trace element of fundamental importance to human health, has been shown to possess several analogous functions. The mechanism by which selenium exerts anticancer and immunomodulatory activity differs from that of polysaccharide fractions, but a similar pharmacological effect suggests a possible synergy of these two agents. Various functions of Se-polysaccharides have been explored, including antitumor, immune-enhancement, antioxidant, antidiabetic, anti-inflammatory, hepatoprotective, and neuroprotective activities. Due to being non-toxic or much less toxic than inorganic selenium compounds, Se-polysaccharides are potential dietary supplements that could be used, e.g., in chemoprevention.

Preliminary study on Se-enriched Lentinula edodes mycelium as a proposal of new feed additive in selenium deficiency

The presence of selenium in European soil is low and this causes its deficiency in livestock and, in consequence, in humans. This study aimed to obtain Lentinula (L.) edodes mycelium with the maximum content of selenium. This species was used for experiment based on its documented medicinal properties. Calves were fed with selenium-enriched L. edodes mycelium, and serum selenium concentration, average daily weight gains and selected immune parameters were estimated. The selenium-enriched mushroom was found to be safe based on cytotoxicity tests (MTT and LDH tests) and for this reason it was used for further experiments. The mean quantity of selenium in the serum of calves fed with selenium-enriched L. edodes mycelium was significantly higher than that of control calves. Additionally, the calves fed with selenium-enriched L. edodes mycelium had higher body weight gains than those of control calves. White blood cell counts and subpopulations of lymphocytes in the experimental and control calves were within the reference range. The administration of L. edodes enriched with selenium had a beneficial effect on state of health of the calves.

Mushrooms: from nutrition to mycoremediation

Mushrooms are well known as important food items. The uses of mushrooms in the cuisine are manifolds and are being utilized for thousands of years in both Oriental and Occidental cultures. Medicinal properties of mushrooms show an immense potential as drugs for the treatment of various diseases as they are rich in a great variety of phytochemicals. In this review, we attempted to encompass the recent knowledge and scientific advancement about mushrooms and their utilization as food or curative properties, along with their natural ability to accumulate (heavy) metals/radionuclides, which leads to an important aspect of bioremediation. However, accumulation of heavy metals and radionuclides from natural or anthropogenic sources also involves potential nutritional hazards upon consumption. These hazards have been pointed out in this review incorporating a selection of the most recently published literature.

Multi-elemental analysis of Lentinula edodes mushrooms available in trade

The present study investigated the content of 62 elements in the fruiting bodies of Lentinula edodes (Shiitake mushroom) cultivated commercially in Poland on various substrates from 2007-2015. The general mean content (mg kg^-1 dry weight (DW)) of the studied elements ranked in the following order: K (26,335) > P (11,015) > Mg (2,284) > Ca (607) > Na (131) > Zn (112) > Fe (69) > Mn (33) > B (32) > Rb (17) > Cu (14.5) > Al (11.2) > Te (2.9) > As (1.80) > Cd (1.76) > Ag (1.73) > Nd (1.70) > Sr (1.46) > Se (1.41) > U (1.11) > Pt (0.90) > Ce (0.80) > Ba (0.61) > Co (0.59) > Tl (0.58) > Er (0.50) > Pb (0.42) > Li (0.40) > Pr (0.39) > Ir (0.37) > In (0.35) > Mo (0.31) > Cr (0.29) > Ni (0.28) > Sb (0.26) > Re (0.24) > Ti (0.19) > Bi (0.18) > Th (0.12) > La (0.10) = Pd (0.10) > Os (0.09) = Zr (0.09) > Rh (0.08) > Ho (0.07) > Ru (0.06) > Sm (0.04) = Eu (0.04) = Tm (0.04) > Gd (0.03) > Sc (0.02) = Y (0.02) > Lu (0.01) = Yb (0.01) = V (0.01). The contents of Au, Be, Dy, Ga, Ge, Hf, and Tb were below the limits of detection (0.02, 0.02, 0.01, 0.01, 0.01, 0.01, 0.02 mg kg^-1 respectively). The concentrations of Al, As, B, Ba, Ca, Cd, Cr, Er, Fe, In, Lu, Mn, Nd, Sr, Ti, Tm, and Zr were comparable over the period the mushrooms were cultivated. The study revealed that Lentinula edodes contained As and Cd at levels potentially adverse to human health. This highlights the need to monitor these elements in food products obtained from this mushroom species and ensure that only low levels of these elements are present in cultivation substrates.

Elm Tree (Ulmus parvifolia) Bark Bioprocessed with Mycelia of Shiitake (Lentinus edodes) Mushrooms in Liquid Culture: Composition and Mechanism of Protection against Allergic Asthma in Mice

Mushrooms can break down complex plant materials into smaller, more digestible and bioactive compounds. The present study investigated the antiasthma effect of an Ulmus parvifolia bark extract bioprocessed in Lentinus edodes liquid mycelium culture (BPUBE) against allergic asthma in chicken egg ovalbumin (OVA)-sensitized/challenged mice. BPUBE suppressed total IgE release from U266B1 cells in a dose-dependent manner without cytotoxicity. Inhibitory activity of BPUBE against OVA-specific IgE secretion in bronchoalveolar lavage fluid (BALF) was observed in OVA-sensitized/challenged asthmatic mice. BPUBE also inhibited OVA-specific IgG and IgG1 secretion into serum from the allergic mice, suggesting the restoration of a Th2-biased immune reaction to a Th1/Th2-balanced status, as indicated by the Th1/Th2 as well as regulatory T cell (Treg) cytokine profile changes caused by BPUBE in serum or BALF. Inflammatory cell counts in BALF and lung histology showed that leukocytosis and eosinophilia induced by OVA-sensitization/challenge were inhibited by the oral administration of BPUBE. Amelioration of eosinophil infiltration near the trachea was associated with reduced eotaxin and vascular cell adhesion molecule-1 (VCAM-1) levels. Changes in proinflammatory mediator levels in BALF suggest that BPUBE decreased OVA-sensitization-induced elevation of leukotriene C4 (LTC4) and prostaglandin D2 (PGD2). The finding that asthma-associated biomarker levels of OVA-sensitized/challenged mice were much more inhibited with BPUBE treatment than NPUBE (not-bioprocessed Ulmus parvifolia extract) treatment suggested the production of new bioactive compounds by the mushroom mycelia that may be involved in enhancing the observed antiasthmatic properties. The possible relation of the composition determined by proximate analysis and GC/MS to observed bioactivity is discussed. The results suggest that the elm tree (Ulmus parvifolia) bark bioprocessed with mycelia of shiitake (Lentinus edodes) mushrooms has the potential to prevent and/or treat allergic asthma.

Protective effect of vanilloids against chemical stress on the white-rot fungus Ganoderma lucidum

Bioremediation of contaminated sites by biosorption of pollutants onto a wide range of materials has emerged as a promising treatment for recalcitrant aromatic compounds or heavy metals. When adsorption occurs on living white-rot fungi mycelia, the pollutants may be degraded by ligninolytic enzymes. However, the survival of mycelia in harsh conditions is one of the drawbacks of those methodologies. In this study, it was demonstrated that culture media supplemented with several guaiacol derivatives (vanilloids) increased the resistance of Ganoderma lucidum E47 cultures to chemical stress by enhancing the adsorptive capacity of the extracellular mucilaginous material (ECMM). The toxicity of the fungicides gentian violet (GV), malachite green (MG) and clotrimazole, and the heavy metal Cadmium was noticeably diminished in fungal cultures supplemented with the guaiacol derivative vanillic acid (VA). No degradation of the tested compounds was detected. The activity of the oxidative enzymatic systems like laccase, a well-known oxidase associated to dye degradation, was only detectable after complete growth on plates. Extremely low concentrations of VA caused a significant protective effect, radial extension of the growth halo in plates supplemented with 0.0001 mM of VA plus GV was up to 20% to that obtained in control plates (without addition of GV and VA). Therefore, the protective effect could not be attributable to VA per se. ECMM separated from the mycelium exhibited a much higher increase in the adsorptive capacity when isolated from liquid cultures containing VA, while that obtained from unsupplemented cultures showed an almost null adsorptive capacity.

Macro and trace mineral constituents and radionuclides in mushrooms: health benefits and risks

This article reviews and updates data on macro and trace elements and radionuclides in edible wild-grown and cultivated mushrooms. A huge biodiversity of mushrooms and spread of certain species over different continents makes the study on their multi-element constituents highly challenging. A few edible mushrooms are widely cultivated and efforts are on to employ them (largely Agaricus spp., Pleurotus spp., and Lentinula edodes) in the production of selenium-enriched food (mushrooms) or nutraceuticals (by using mycelia) and less on species used by traditional medicine, e.g., Ganoderma lucidum. There are also attempts to enrich mushrooms with other elements than Se and a good example is enrichment with lithium. Since minerals of nutritional value are common constituents of mushrooms collected from natural habitats, the problem is however their co-occurrence with some hazardous elements including Cd, Pb, Hg, Ag, As, and radionuclides. Discussed is also the problem of erroneous data on mineral compounds determined in mushrooms.