The hypocholesterolemic effect of extracellular polysaccharide from the submerged fermentation of mushroom

Effects of in vitro simulated digestion and fecal fermentation of polysaccharides from straw mushroom (Volvariella volvacea) on its physicochemical properties and human gut microbiota

Herein, the fermentation and digestion behavior of Volvariella volvacea polysaccharide (VVP) were examined through the in vitro simulation experiment. The results revealed that succeeding the simulated salivary gastrointestinal digestion, the molecular weight of VVP was reduced by only 8.9 %. In addition, the reducing sugar, uronic acid, monosaccharide composition and Fourier transform infrared spectroscopy characteristics of VVP did not change significantly, which indicate that saliva-gastrointestinal could not digest VVP. However, 48 h of fecal fermentation of VVP dramatically reduced its molecular weight by 40.4 %. Furthermore, the molar ratios of the monosaccharide composition altered considerably due to the degradation of VVP by microorganisms and the metabolysis into different short-chain fatty acids (SCFAs). Meanwhile, the VVP also raised the proportion of Bacteroidetes to Firmicutes and promoted the proliferation of some beneficial bacteria including Bacteroides and Phascolarctobacterium, whereas it inhibited the growth of unfavorable bacteria such as Escherichia-shigella. Therefore, VVP has the potential to have a positive influence on health and hinder diseases by improving the intestinal microbial environment. These findings provide a theoretical foundation to further develop Volvariella volvacea as a healthy functional food.

Concentration of NK cells after β-glucan and vitamin D supplementation in patients with diabetic retinopathy

In our study, we focused on possible effects of supplementation with glucan and vitamin D on total numbers of NK cells in patients with diabetic retinopathy. We evaluated possible relations among nutritional state (BMI), leptin levels, and total numbers of NK cells in patients supplemented with (1) glucan and vitamin D, (2) vitamin D and placebo, and (3) vitamin D alone. Our results show that 3 months of supplementation with both glucan and vitamin D resulted in significant improvements of NK cell numbers. In addition, we found statistically significant correlation between NK cell numbers and leptin levels. Based on these results, we propose that the molecule responsible for these changes is glucan, as vitamin D alone or together with placebo caused no effects.

Optimization of Polysaccharide Production from Cordyceps militaris by Solid-State Fermentation on Rice and Its Antioxidant Activities

Polysaccharides are an important class of bioactive components of medical mushroom and herbs and are now used as natural drugs or dietary supplements on a global scale. In this paper, we aimed to increase the polysaccharide production of Cordyceps militaris and the antioxidant activities of fermented rice by solid-state fermentation. The media components and culture condition were optimized by orthogonal design and mono-factor tests using rice as the raw material. The optimal media consisted of (g/L): rice (50), fructose (7), glycerin (7), peptone (1), MgCl₂ (0.11), VB₁ (0.05), VB₂ (0.05), CaCl₂ (1.5), corn bran (6), and a water-materials ratio of 100%. The fermentation condition was as follows: inoculum volume of 5.5% (v/w), rice weight of 50 g in one bowl with a diameter of 120 mm and a depth of 90 mm, incubation temperature of 26 °C, and incubation time of seven days. Under the optimized condition, the maximal C. militaris polysaccharide content and free radical scavenging ratio were 68.3 mg/g dry substrate and 98.9%, respectively. This study provides a new strategy for the production of healthy food from traditional food.

Phenolic profiles, antioxidant, and anticholinesterase activities of three Gloeophyllum species with chemometric approach

This study's aim was to determine the antioxidant and anticholinesterase activities of Gloeophyllum odoratum, Gloeophyllum sepiarium, and Gloeophyllum trabeum species with phenolic profiles. The major compound in G. odoratum (101.6 µg/g) and G. sepiarium (92.61 µg/g) mushrooms was fumaric acid, while ferulic acid was found as the main compound in G. trabeum (11.67 μg/g). The methanol extracts of Gloeophyllum species exhibited the highest activity in CUPRAC, DPPH^• , β-carotene-linoleic acid, and ABTS^•+ assays while the n-hexane extracts showed the highest activity in the metal chelating assay. Also, the methanol extract of G. odoratum (IC₅₀ : 32.16 ± 0.28 µg/mL) was found to be highly active than its antioxidant standard α-tocopherol (IC₅₀ : 38.51 ± 0.54 µg/mL) in the ABTS^•+ radical scavenging assay. All the studied Gloeophyllum species extracts were found to be moderate inhibitors against AChE, whereas G. sepiarium n-hexane extract (69.70 ± 1.92%) and G. odoratum n-hexane extract (58.08 ± 1.36%) exhibited potent BChE inhibitory activity. PRACTICAL APPLICATIONS: The results of these studies demonstrated that the methanol and the n-hexane extracts had a potential application as alternative natural products for pharmaceutical, food, and cosmetic industries. In addition, the chemometric analysis by principal component analysis and hierarchical clustering analysis techniques could be used for the classification of the extracts of Gloeophyllum according to their bioactivity results. This is the first comprehensive study on phenolic profiles and bioactivities of G. odoratum, G. sepiarium, and G. trabeum mushroom species.

Isolation and characterization of extracellular polysaccharide Thelebolan produced by a newly isolated psychrophilic Antarctic fungus Thelebolus

The present investigation is on a newly isolated psychrophilic Antarctic filamentous Ascomycetous fungus that has been identified as Thelebolus sp. and given the designation of Thelebolus sp. IITKGP-BT12. The culture was primarily identified through morphological studies, and was further confirmed by 18S rRNA sequencing (GenBank Accession No. KC191572), which revealed its close relatedness with Thelebolus microsporus. The exopolysaccharide (EPS) produced (1.94 g L(-1)) by the fungus was isolated, purified and characterized as glucan having an average molecular mass of 5×10(5)Da. The structure of EPS was determined by gas chromatography with tandem mass spectrometry (GC-MS/MS), Fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance (NMR) studies ((1)H, (13)C and HSQC). NMR analysis indicated the presence of (1→3)-linked β-d-glucan backbone with (1→6)-linked branches of β-d-glucopyranosyl units. Antiproliferative activity of EPS was demonstrated in B16-F0 cells, with IC50 of 275.42 μg m L(-1). Flow cytometry analysis and DNA fragmentation studies revealed that the cytotoxic action of the EPS mediated apoptosis in cancer cells. This is the first ever report on bioactive EPS thelebolan from Thelebolus sp.

Hypoglycemic and Hypocholesterolemic Effects of Botryosphaeran from Botryosphaeria rhodina MAMB-05 in Diabetes-Induced and Hyperlipidemia Conditions in Rats

Botryosphaeran, a water-soluble exopolysaccharide of the β-(1 → 3;1 → 6)-D-glucan type that has been isolated from the culture medium of Botryosphaeria rhodina MAMB-05 grown in submerged fermentation using glucose as the sole carbon source, was previously demonstrated to be non-genotoxic in peripheral blood and bone marrow, and exhibited strong anticlastogenic activity. In the present study, the effects of botryosphaeran were investigated in streptozotocin-induced diabetic rats as well as in high-fat diet-fed hyperlipidemic Wistar rats. The plasma glucose level was reduced by 52% in the diabetic group of rats after administration of 12 mg botryosphaeran/kg body weight of the rats (b.w.)/day by gavage over 15 days. A reduction in the median ration intake was accompanied by an increase in the median body weight gain, as well as the efficiency of food conversion. These results demonstrate that botryosphaeran has protective effects by reducing the symptoms of cachexia in Diabetes mellitus. Botryosphaeran administered by gavage at a concentration of 12 mg botryosphaeran/kg b.w./day over 15 days also reduced the plasma levels of total cholesterol and low density lipoprotein-cholesterol by 18% and 27%, respectively, in hyperlipidemic rats. Based on these findings, we conclude that botryosphaeran possesses hypoglycemic and hypocholesterolemic properties in conditions of diabetes mellitus and hyperlipidemia, respectively, and may be used as an oral anti-diabetic agent.

Hypocholesterolemic effect of hot-water extract from mycelia of Cordyceps sinensis

This study was conducted to investigate the hypocholesterolemic effect of the hot-water fraction (HW) from cultured mycelia of Cordyceps sinensis in a 5 l fermenter. The composition of HW was mainly carbohydrate (83.9%) and protein (11.8%) on a dry basis, and the carbohydrate of HW consisted of glucose, mannose, galactose, and arabinose in the molecular ratio of 1.0 : 0.8 : 0.5 : 0.1, respectively. In mice fed a cholesterol-free diet and those fed a cholesterol-enriched diet, body and liver weights were not significantly different from those of the controls. The serum total cholesterol (TC) of all mice groups administered HW (150 and 300 mg/kg/d, respectively) with the cholesterol-enriched diet decreased more than in the control group. Among the mice fed the cholesterol-enriched diet, HW also increased the high-density lipoprotein (HDL) cholesterol level, but decreased the very low-density lipoprotein plus low-density lipoprotein (VLDL+LDL) cholesterol level. The changes in HDL- and VLDL+LDL-cholesterol levels consequently decreased the atherogenic value. The results indicate that HW in rats administered a cholesterol-enriched diet decreased the plasma cholesterol level. The 300 mg/kg dose had a significant effect on the serum TC level.

Production and structural characterization of the exopolysaccharide of the Antarctic fungus Phoma herbarum CCFEE 5080

The filamentous fungus Phoma herbarum CCFEE 5080 isolated from continental Antarctica soil was tested for exopolysaccharide (EPS) production. The fungus grew and produced EPS (up to 13.6 g/l) on a variety of carbon sources among which sorbitol was best, particularly at the concentration of 60 g/l. EPS production was maximum when the nitrogen source was NaNO3 (3 g/l) and the incubation temperature was 28 degrees C. The polysaccharide was purified by repeated precipitation in ethanol and gel filtration and characterized as a homopolymer of glucose having a molecular weight of 7.412 x 10(6); structural analysis indicated the presence of beta-1,3 and beta-1,6 linkages only. After repeated freezing and thawing of the fungal biomass in the presence of EPS, the mycelial growth was much higher than that observed after freezing in the absence of EPS and the difference increased with the number of freeze-thaw cycles. It is hypothesized that the adaptation of P. herbarum CCFEE 5080 to the Antarctic soil microclimatic conditions, characterized by low temperature, high thermal fluctuations and repeated freeze-thaw cycles, might be related to the EPS production ability.

Plasma and hepatic cholesterol levels and fecal neutral sterol excretion are altered in hamsters fed straw mushroom diets

The effect of the fruiting body and mycelium of Volvariella volvacea (straw mushroom) on the concentrations of plasma lipids, liver cholesterol, fecal neutral sterol and bile acid excretions was investigated in male Golden Syrian hamsters. The hamsters were fed a purified hypercholesterolemic diet (0.1% cholesterol, 10% fat) for 4 wk to elevate plasma lipid concentrations. Twelve hamsters with elevated plasma total cholesterol were randomly assigned to each treatment group: control (5% cellulose), mushroom fruiting body (5%) and mushroom mycelium (5%). After 4 wk of mushroom diet consumption, the plasma total cholesterol, HDL cholesterol, and combined VLDL + LDL cholesterol concentrations (mmol/L) were significantly lower than control in the group fed the fruiting body-diet (40, 38 and 43%, respectively) (P < 0.05). The liver cholesterol levels were significantly lower in both the mushroom fruiting body- and the mycelium-fed groups (28 and 21% in terms of concentration; 39 and 30% in terms of total content, respectively) (P < 0.05) than that in the control group. Fecal neutral sterol excretion in the mushroom fruiting body- and mycelium-fed groups was significantly higher (81 and 74%, respectively) (P < 0.05) than that in the control group. Although no significant differences (P > 0.05) in the excretion of fecal bile acids were observed among groups fed the mushroom diets and the control diet, the mushroom fruiting body diet-fed hamsters apparently had less bacterial degradation of cholic acid as indicated by a significantly greater proportion (P < 0.05) of fecal cholic acid than in controls. They also had a significantly lower proportion of fecal deoxycholic acid (P < 0.05). This study suggests that the fruiting body of the straw mushroom lowers elevated plasma cholesterol in hypercholesterolemic hamsters, whereas the mycelium does not.