Lipid lowering effects of oyster mushroom (Pleurotus ostreatus) in humans

Role of thymol on hyperglycemia and hyperlipidemia in high fat diet-induced type 2 diabetic C57BL/6J mice

Thymol is a monoterpene phenol with many pharmacological activities, but their anti- hyperglycemic and anti-hyperlipidemic activities are not yet explored. This study evaluates the beneficial effects of thymol on plasma, hepatic lipids and hyperglycaemic effects in high-fat diet (HFD) induced type 2 diabetes in C57BL/6J mice. These mice were fed continuously with high fat diet (fat- 35.8%) for 10 weeks and subjected to intragastric administration of various doses (10mg, 20mg and 40mg/kg body weight (BW)) of thymol daily for the subsequent 5 weeks. Body weight (BW), food intake, plasma glucose, insulin, insulin resistance, HbA1c, leptin and adiponectin were significantly decreased and there was an increase in food efficacy ratio. Thymol supplementation were significantly lowered the concentration of plasma triglyceride (TG), total cholesterol (TC), free fatty acids (FFAs), low density lipoprotein (LDL) and increased high density lipoprotein (HDL) cholesterol as compared to the HFD induced diabetic group due to lipid enzymatic activity. Also, the hepatic lipid contents such as triglycerides, total cholesterol, free fatty acid and phospholipids (PL) were significantly lowered in the thymol supplemented groups. As compared to other two tested doses of 10mg and 20mg, thymol (40mg/kg BW) were showed significant protective effect on the parameters studied. Thus, indicate thymol protects C57BL/6J mice against HFD due to its anti-hyperglycaemic and anti-hyperlipidemic activity. The above outcome concludes that thymol may exhibit promising anti-diabetic activity.

Extraction of a soluble polysaccharide from Auricularia polytricha and evaluation of its anti-hypercholesterolemic effect in rats

Mushroom extracts are a new source of supplements for health and pharmaceutical due to their bioactivities. This study was to optimize the extraction parameters of a soluble polysaccharide from Auricularia polytricha (SPAP) by response surface methodology. The practical optimum parameters were an extraction time of 4h, an extraction temperature of 95 °C and a ratio of water to fruiting bodies of 28 mL/g, and the highest extraction rate was 19.77%. In vivo, male Sprague-Dawley (SD) rats were diet-induced hypercholesterolemic models and oral administration of SPAP to evaluate anti-hypercholesterolemic effects. The results showed that SPAP decreased the serum concentrations of blood lipid, made them close to the normal level. The total cholesterol in the SPAP consumption groups was significantly decreased 34.6 ± 7.6% and 33.3 ± 7.9% with dose of 4.5 and 9.0mg/kg BW in the 29th day. This study suggested that SPAP was a suitable natural agent and may be applied in therapy.

Efficient synthesis and characterization of ergosterol laurate in a solvent-free system

Ergosterol and its derivatives have attracted much attention for a variety of health benefits, such as anti-inflammatory and antioxidant activities. However, ergosterol esters are advantageous because this compound has better solubility than the free ergosterol. In this work, ergosterol laurate was efficiently synthesized for the first time by direct esterification in a solvent-free system. The desired product was purified, characterized by Fourier transform infrared spectroscopy, mass spectrometry, and nuclear magnetic resonance, and finally confirmed to be ergosterol laurate. Meanwhile, the effect of various catalysts, catalyst dose, reaction temperature, substrate molar ratio, and reaction time were studied. Both the conversion of ergosterol and the selectivity of the desired product can reach above 89% under the selected conditions: sodium dodecyl sulfate + hydrochloric acid as the catalyst, 2:1 molar ratio of lauric acid/ergosterol, catalyst dose of 4% (w/w), 120 °C, and 2 h. The oil solubility of ergosterol and its laurate was also compared. The results showed that the solubility of ergosterol in oil was significantly improved by direct esterification with lauric acid, thus greatly facilitating the incorporation into a variety of oil-based systems.

Ameliorating Effect of Mycoleptodonoides aitchisonii on High-fat Diet-induced Obese Mice

The present study investigated the anti-obesity effects of Mycoleptodonoides aitchisonii (MA) in mice fed a high-fat (HF) diet. Two groups were fed either a normal control diet or an HF (45% kcal fat) diet for 12 weeks and three groups were fed an HF diet supplemented with powdered MA (MAP, 1%, 3%, and 5%) for 12 weeks. The anti-obesity effects of MAP supplementation on body weight, fat mass development, and lipid-related markers were assessed. Consumption of an HF diet resulted in increased body weight, serum lipids, relative adipose tissues weight, and liver fat accumulation. However, administration of MAP significantly decreased body weight gain, food intake, food efficiency ratio, hepatic cholesterol level, and adipose tissue weight in a dose-dependent manner. In addition, treatment with MAP significantly reduced the occurrence of fatty liver deposits and steatosis, and inhibited an HF diet-induced increase in adipocyte size. These results suggest that dietary supplementation with MAP exerts anti-obesity effects and indicate that MAP could be used as a functional food to control obesity.

Effects of UV-B Radiation Levels on Concentrations of Phytosterols, Ergothioneine, and Polyphenolic Compounds in Mushroom Powders Used As Dietary Supplements

Compositional changes of powder dietary supplements made from mushrooms exposed to different levels of UV-B irradiation were evaluated for the bioactive naturally occurring mushroom antioxidant, ergothioneine; other natural polyphenolic compounds, e.g., flavonoids, lignans, etc.; and selected phytosterols. Four types of mushroom powder consisting of white, brown (Agaricus bisporus), oyster (Pleurotus ostreatus), and shiitake (Lentinula edodes) mushrooms from three different treatment groups (control, low and high UV-B exposures) were evaluated. Ergothioneine concentrations found in mushroom powders were 0.4-10.4 mg/g dry weight (dw) and were not appreciably affected by UV-B radiation. No individual polyphenols were detected above 0.1 μg/g. Phytosterols ergosterol (2.4-6.2 mg/g dw) and campesterol (14-43 μg/g dw) were measured in mushroom powder samples. Ergosterol concentrations decreased significantly with the increased level of UV-B treatment for all mushroom powder types, except for white. These results provide some new information on effects of UV-B radiation on these important natural bioactive compounds in mushrooms.

Dynamics of sterols and fatty acids during UV-B treatment of oyster mushroom

Fruiting bodies of the oyster mushroom Pleurotus ostreatus were illuminated with UV-B with a light intensity maximum at 310-320 nm and 11.5 W/m² for 60 min at 20 °C. Changes of the sterol and fatty acid spectrum were quantified. The onset of ergocalciferol (vitamin D₂) formation was immediate in fruiting bodies illuminated from the lamella side, in sliced fruiting bodies, and in the stipes. Saturation concentrations above 100 μg/g of dry matter were reached after 1h. At the same time, the concentrations of the photo-isomers lumisterol₂, tachysterol₂ and previtamin D₂ increased in this order. 22-Dihydroergocalciferol (vitamin D₄), showed the same course of increase and reached a maximum concentration of around 20 μg/g dry matter. With the exception of linoleic acid in cut fruiting bodies, fatty acid concentrations remained almost constant. One serving of UV-B pretreated sliced oyster mushroom covered the weekly demand of vitamin D of an adult.

Study on the 3-hydroxy-3-methyl-glutaryl CoA reductase inhibitory properties of Agaricus bisporus and extraction of bioactive fractions using pressurised solvent technologies

BACKGROUND

Agaricus bisporus mushrooms were able to lower cholesterol levels in hypercholesterolaemic rats and it was suggested that dietary fibre might inhibit cholesterol absorption. However, A. bisporus extracts were also able to inhibit the 3-hydroxy-3-methyl-glutaryl CoA reductase (HMGCR, the key enzyme in the cholesterol biosynthetic pathway) and this might also contribute to the observed lowering of cholesterol levels in serum.

RESULTS

The methanol-water extracts obtained from A. bisporus were able to inhibit up to 60% the HMGCR activity using an in vitro assay. The HMGCR inhibitory capacities depended on cultivation conditions, strains, etc. The potential inhibitors were not statins, they might be β-glucans able to scavenge the substrate and impair the enzymatic reaction. They were present during all mushroom developmental stages and similarly distributed through all the tissues including the parts discarded as a by-product. Accelerated solvent extractions using 1:1 ethanol-water as pressurised solvent (10.7 MPa, 25°C, five cycles of 5 min) were more effective in the extraction of the HMGCiR inhibitor(s) than supercritical fluid extractions (9 MPa, 40°C) using CO2 with 10% ethanol.

CONCLUSION

A mushroom cultivation and two extraction procedures were optimised to obtain fractions from A. bisporus with high HMGCR inhibitory activities to design novel ingredients for hypocholesterolaemic functional foodstuffs.

Chemical properties of a polysaccharide purified from solid-state fermentation of Auricularia auricular and its biological activity as a hypolipidemic agent

A water-soluble crude polysaccharide was extracted by hot water from Auricularia auricular mycelium grown under solid-state fermentation (SSF). The crude polysaccharide was purified by DEAE Sephadex A-50 and Sephadex G-200 chromatography. Fourier transform infrared spectroscopy and nuclear magnetic resonance ((1) H NMR) spectroscopy were used to investigate the structure of the purified A. auricular polysaccharide (AAP-I) and revealed that it is α-glycosidically linked. After 14 and 28 days of AAP-I orally administered, the AAP-I significantly decreased the levels of total cholesterol, triglyceride, and low-density lipoprotein cholesterol in mice in which hyperlipidemia had been induced by a high fat diet (P < 0.05). The results revealed that AAP-I from SSF of A. auricular mycelium possesses potent hypolipidemic properties. The polysaccharide may be useful as a functional food additive and a hypolipidemic agent.

Beta-Glucan-Rich Extract from Pleurotus sajor-caju (Fr.) Singer Prevents Obesity and Oxidative Stress in C57BL/6J Mice Fed on a High-Fat Diet

Mushrooms have been used in folk medicine for thousands of years. In this study, the effect of β-glucan-rich extract of P. sajor-caju (GE) on lipid lowering and antioxidant potential was assessed in C57BL/6J mice fed on a high-fat diet. Obesity was induced in C57BL/6J mice by feeding a high-fat diet. The control groups in this study were ND (for normal diet) and HFD (for high-fat diet). The treated groups were ND240 (for normal diet) (240 mg/kg b.w) and HFD60, HFD120, and HFD240 (for high-fat diet), where the mice were administrated with three dosages of GE (60, 120, and 240 mg GE/kg b.w). Metformin (2 mg/kg b.w) served as positive control. GE-treated groups showed significantly reduced body weight, serum lipid, and liver enzymes levels. GE also attenuated protein carbonyl and lipid hydroperoxide levels by increasing the enzymic antioxidants (SOD, CAT, and GPx) activities in the mice. GE-treated groups induced the expression of hormone sensitive lipase (HSL) and adipose triglyceride lipase (ATGL) while downregulated the expression of peroxisome proliferator-activated receptor gamma (PPAR-γ), sterol regulatory binding protein-1c (SREBP-1c), and lipoprotein lipase (LPL). Hence, GE prevented weight gain in the mice by inducing lipolysis and may be valuable in the formulation of adjuvant therapy for obesity.

Glucan-rich polysaccharides from Pleurotus sajor-caju (Fr.) Singer prevents glucose intolerance, insulin resistance and inflammation in C57BL/6J mice fed a high-fat diet

Background

Pleurotus sajor-caju (P. sajor-caju) has been extremely useful in the prevention of diabetes mellitus due to its low fat and high soluble fiber content for thousands of years. Insulin resistance is a key component in the development of diabetes mellitus which is caused by inflammation. In this study, we aimed to investigate the in vivo efficacy of glucan-rich polysaccharide of P. sajor-caju (GE) against diabetes mellitus and inflammation in C57BL/6J mice fed a high-fat diet.

Methods

Diabetes was induced in C57BL/6J mice by feeding a high-fat diet. The mice were randomly assigned to 7 groups (n=6 per group). The control groups in this study were ND (for normal diet) and HFD (for high-fat diet). The treated groups were ND240 (for normal diet) (240 mg/kg b.w) and HFD60, HFD120 and HFD240 (for high-fat), where the mice were administrated with three dosages of GE (60, 120, 240 mg GE/kg b.w respectively). Metformin (2 mg/kg b.w) served as positive control. The glucose tolerance test, glucose and insulin levels were measured at the end of 16 weeks. Expressions of genes for inflammatory markers, GLUT-4 and adiponectin in the adipose tissue of the mice were assessed. One-way ANOVA and Duncan’s multiple range tests (DMRT) were used to determine the significant differences between groups.

Results

GE treated groups improved the glucose tolerance, attenuated hyperglycemia and hyperinsulinemia in the mice by up-regulating the adiponectin and GLUT-4 gene expressions. The mice in GE treated groups did not develop insulin resistance. GE also down-regulated the expression of inflammatory markers (IL-6, TNF-α, SAA2, CRP and MCP-1) via attenuation of nuclear transcription factors (NF-κB).

Conclusion

Glucan-rich polysaccharide of P. sajor-caju can serve as a potential agent for prevention of glucose intolerance, insulin resistance and inflammation.

Dietary Shiitake Mushroom (Lentinus edodes) Prevents Fat Deposition and Lowers Triglyceride in Rats Fed a High-Fat Diet

High-fat diet (HFD) induces obesity. This study examined the effects of Shiitake mushroom on the prevention of alterations of plasma lipid profiles, fat deposition, energy efficiency, and body fat index induced by HFD. Rats were given a low, medium, and high (7, 20, 60 g/kg = LD-M, MD-M, HD-M) Shiitake mushroom powder in their high-fat (50% in kcal) diets for 6 weeks. The results showed that the rats on the HD-M diet had the lowest body weight gain compared to MD-M and LD-M groups (P < 0.05). The total fat deposition was significantly lower (-35%, P < 0.05) in rats fed an HD-M diet than that of HFD group. Interestingly, plasma triacylglycerol (TAG) level was significantly lower (-55%, P < 0.05) in rats on HD-M than HFD. This study also revealed the existence of negative correlations between the amount of Shiitake mushroom supplementation and body weight gain, plasma TAG, and total fat masses.

Variations and Hybridization Compatibility of Single Basidiospore Isolates of Pleurotus sajor-caju (Fr.) Sings

Pleurotus sajor-caju (Fr.) Sings, a mushroom of the family Pleurotaceae, is gaining popularity due to its high nutrient content and capability of growing on various agricultural wastes. There is a need to breed new strain of P. sajor-caju to meet the rising demands of the increasing human population. Strain improvement is achievable through selection and hybridization. Unfortunately, there is limited information regarding the genetic variations of P. sajor caju in Malaysia. Therefore, this study is of interest to document the morphological variations of single basidiospore isolates and to generate hybrids. A total of 200 single basidiospore isolates (SB) obtained from a commercialized strain of P. sajor-caju were obtained from local supermarket in Kuching, Sarawak, and cultured individually on potato dextrose agar. These 200 SBs were characterized morphologically and divided into three main groups based on colony morphology i.e. scattered, rough and smooth. Variations can still be observed in each main group. From each main group, SBs representing the variations were further categorized based on their colony diameter growth after 7 days of post inoculation (CD-7dpi), i.e. slow growing CD-7dpi (SGCD-7), medium fast growing CD-7dpi (MFGCD-7) and fast growing CD-7dpi (FGCD-7). Ten FGCD-7 and ten SGCD-7 isolates were selected for hybridization. The selected SBs were hybridized in all possible pairings without repetition. Sixteen hybridized isolates were recognized and characterized based on CD-7dpi. For all FGCD-7 pairings, SGCD-7 pairings, and between FGCD-7 and SGCD-7 pairings, hybridized isolates had higher CD-7dpi than at least one of its parents were identified. The new hybridized isolates are interesting materials for future study.