Identification and preparation of selenium-containing peptides from selenium-enriched Pleurotus eryngii and their protective effect on lead-induced oxidative damage in NCTC1469 hepatocytes.

BACKGROUND: Lead (Pb) is a highly toxic and persistent substance that easily accumulates in living organisms, eliciting cellular toxicity and oxidative stress. Some selenium-containing proteins and peptides prepared from plant extracts are beneficial for protecting the body's health and resisting external disturbances. In the present study, selenium-containing peptide species were prepared from selenium-enriched Pleurotus eryngii protein hydrolysates and to evaluate the benefits of selenium-containing peptides on Pb-induced oxidative stress in NCTC1469 hepatocytes. RESULTS: Trypsin was selected as primary enzyme to hydrolyze the selenium-enriched protein (SPH). The optimal hydrolysis conditions were: hydrolysis time, 1.5 h; initial pH 8.0. The SPH was digested by trypsin and then purified by ultrafiltration, gel filtration chromatography and reversed-phase HPLC to obtain the selenium-containing peptides SPH-I-2. Furthermore, SPH-I-2 was analyzed and a number of total 12 selenium-containing peptides were identified by liquid chromatography-tandem mass spectroscopy. The NCTC1469 cell culture study showed that selenium-containing peptides were capable of reducing reactive oxygen species levels and regulating the Keap1/Nrf2 pathway by upregulating Nrf2, HO-1, GCLC, GCLM and NQO1 genes and downregulating Keap1 genes. Moreover, selenium-containing peptides were also able to suppress Pb-induced elevated levels of nitric oxide (NO), lactate dehydrogenase (LDH), malondialdehyde (MDA), increase antioxidant enzyme activity and alleviate cell apoptosis. CONCLUSION: The present study indicated that the selenium-containing peptides could protect cells from Pb2+ -induced oxidative stress. © 2023 Society of Chemical Industry.

Biosynthesis, behavior and fate of volatile organic sulfide in Lentinus edodes (Berk.) upon hot-air drying treatment.

This study elucidated the biosynthesis and changing behaviors of organic sulfide in shiitake mushrooms upon hot-air drying treatment. The changes of aw, moisture migration, contours of taste and flavor, organic sulfide, and 4 key enzyme activities were monitored throughout three drying procedures (CT/ST1/ST2). Results showed that drying rate was related to the moisture migration. Key enzymes of γ-GTase, ASFase and CS lyase were heat-resistant proteases, while C-Dase exhibited low thermal stability with the activity decreased during treatment. A total of 17 organic sulfides were identified and PLS analyses suggested 6 cyclic polysulfides were formed by C-Dase desulfurization, while 5 thioethers generation were related to the thermal cleavage of direct precursors (straight-chain di/tris/tetrasulfonyl esters) and Maillard reaction. These results indicated that ST2 drying procedures had a positive effect on the formation of cyclic polysulfides at the end of drying pried and the achievement of premium flavor qualities.

Zwitterionic meso-silica/polypeptide hybrid nanoparticles for efficient azithromycin delivery and photodynamic therapy for synergistic treatment of drug-resistant bacterial infection.

The treatment of drug-resistant bacterial infections attributed to the overuse of antibiotics still remains a serious challenge globally. Herein, zwitterionic charge switchable meso-silica/polypeptide hybrid nanoparticles (MSPNs) were prepared for the synergistic chemo-photodynamic therapy in the treatment of drug-resistant bacterial infections. Subsequently, azithromycin (AZT) and methylene blue (MB) were loaded in the MSPNs to form the combined chemo-photodynamic therapeutic nanoparticles (MSPNs-AZT/MB) for the treatment of methicillin-resistant Staphylococcus aureus (MRSA). Remarkably, the as-prepared MSPNs-AZT/MB exhibited a negative surface charge of -5.2 mV at physiological pH while switching into positive surface charge of 24.7 mv in an acidic environment, leading to enhanced binding with bacterial surface. The lipase-triggered AZT release up to 77.9 % was achieved, and the loaded MB demonstrated efficient singlet oxygen (1O2) generation for photodynamic therapy. The in vitro experimental results displayed an excellent antibacterial effect against MRSA in both planktonic and biofilm phenotypes. Additionally, the as-prepared MSPNs-AZT/MB exhibited synergistic and enhanced antibacterial infection effect up to 94 % comparing to monotherapy in a mice model. Considering the above advantages, the as-prepared combined chemo-photodynamic therapeutic nanoparticles showed promising biocompatibility and clinical potential for the efficient therapy of drug-resistant bacteria.

Selenium biofortification in Pleurotus eryngii and its effect on lead adsorption of gut microbiota via in vitro fermentation.

It is of great significance to develop safe and efficient dietary selenium sources to improve lead toxicity. In this study, selenate, selenite, SeMet and Se-yeast were supplied to investigate the Se biofortification and bioaccessibility in Pleurotus eryngii. The effects of Se-enriched P. eryngii on lead binding bacteria were investigated via in vitro fermentation. With 40 mg/kg Se in the substrate, the total Se contents of P. eryngii treated with selenite and Se-yeast were 145.22 ± 8.00 mg/kg and 90.01 ± 7.01 mg/kg, respectively. Compared with selenite, Se-yeast treatment significantly increased the organic Se proportion in P. eryngii (SeCys2 2.85 ± 0.17%, MeSeCys 2.33 ± 0.21% and SeMet 78.19 ± 1.58%), which led to higher bioaccessibility. With 1 mg/L lead treatment during in vitro fermentation, Se-enriched P. eryngii promoted the growth of Desulfovibrio, which contributed to the increase of gut microbiota lead adsorption. Se-enriched P. eryngii cultivated with Se-yeast could be used as dietary Se sources for lead toxicity improvement.

Gold nanorods conjugated with biocompatible zwitterionic polypeptide for combined chemo-photothermal therapy of cervical cancer.

Combined chemo-photothermal therapy of gold nanorods (GNRs) for cancer treatment shows better therapeutic efficiency than mono-chemotherapy, which has gained worldwide interests of scientists and clinician in both laboratory and clinic application. However, high cytotoxicity, declined delivery efficiency, and unsatisfactory therapy effect of the GNRs are still challenging in anti-cancer treatment. Herein, a series of pH-sensitively zwitterionic polypeptide conjugated GNRs were synthesized via a gold-thiol interaction for combination of chemo-photothermal therapy in cervical cancer treatment. The acid-labile hydrazone bond was utilized to incorporate the doxorubicin (DOX) for pH-sensitive drug release under tumoral environment. The as prepared GNRs conjugates demonstrated pH-triggered surface charge conversion from negative to positive when transporting from blood circulation to tumor extracellular environment, which can facilitate the cellular uptake via electrostatic interaction. After cellular internalization, the drug release was promoted by cleavage of the hydrazone in GNRs conjugates under cancer intracellular acid environment. As the effective near-infrared (NIR) photothermal materials, the as prepared GNRs conjugates can absorb NIR photo energy and convert it into heat under irradiation, which can efficiently kill the tumor cells. In cell assay, the GNRs conjugates displayed excellent biocompatibility against normal cell, enhanced cancer cell uptake, and remarkable cancer cell killing effects. In HeLa tumor-bearing mice, the GNRs conjugates demonstrated enhanced tumor inhibition efficacy by combination of chemo-photothermal therapy.

Comparison of effects on colitis-associated tumorigenesis and gut microbiota in mice between Ophiocordyceps sinensis and Cordyceps militaris.

BACKGROUND: Gut microbiota plays an indispensable role in the treatment of inflammatory bowel disease (IBD) and colitis-associated cancer (CAC). As traditional medicinal fungi, previous studies have shown that Ophiocordyceps sinensis could better maintain intestinal health via promoting the growth of probiotics in vitro compared with Cordyceps militaris. However, the detailed pharmacological activities and clinical efficacy of O. sinensis and C. militaris are still elusive. PURPOSE: We aimed to evaluate the different actions of O. sinensis and C. militaris on colitis-associated tumorigenesis in Azoxymethane (AOM)/Dextran Sulfate Sodium (DSS)-treated mice and explore the potential gut microbiota-dependent mechanisms. METHODS: C57BL/6 mice (Male, 4 weeks old) were used to construct the AOM/DSS-induced CAC mice model. The mice were administered with 0.6 mg/g/d O. sinensis or C. militaris for 12 weeks. It's worth noting that fecal microbiota transplantation (FMT) and antibiotic treatment were used to investigated the complex interactions between the medicinal fungi, gut microbiota and colonic tumorigenesis. RESULTS: O. sinensis treatment significantly increased the body weight and survival rate, reduced the number of colon tumors, improved the damage of colon epithelial tissue, restored the crypt structure and alleviate the colonic inflammation in AOM/DSS-treated mice. RT-qPCR results indicated that O. sinensis partly regulated the Wnt/ß-catenin signaling via alleviating the overexpression of ß-catenin, TCF4 and c-Myc genes in adjacent noncancerous tissues. Compared with C. militaris, O. sinensis showed better anti-tumor activity. Gut microbiota analysis revealed that O. sinensis reversed the decline of gut microbiota diversity and the structural disorder induced by AOM/DSS. Spearman's correlation analysis showed that O. sinensis promoted the growth of Parabacteroides goldsteinii and Bifidobacterium pseudolongum PV8-2, which were positively correlated with the anti-tumor activity and the production of SCFAs. FMT combined with antibiotic treatment showed that horizontal fecal transfer derived from O. sinensis-treated mice improved the intestinal inflammation and alleviated the colitis-associated tumorigenesis, which was consistent with the direct ingestion of O. sinensis. CONCLUSION: O. sinensis could better attenuate colitis-associated tumorigenesis compared with C. militaris. These effects might be at least partially due to the increased abundance of probiotics, especially P. goldsteinii and B. pseudolongum PV8-2.

Polysaccharide from Flammulina velutipes attenuates markers of metabolic syndrome by modulating the gut microbiota and lipid metabolism in high fat diet-fed mice.

Natural biological macromolecules with putative functions of gut microbiota regulation possess the advantage of improving metabolic syndrome (MS). In this research, we aimed to determine the effects of Flammulina velutipes polysaccharide (FVP) (Expt. 1) and fecal microbiota transplantation (FMT) (Expt. 2) on MS-related disorders, gut microbiota structure changes and their underlying mechanisms in a murine model fed with high-fat diet (HFD). In Expt. 1, six-week-old male C57BL/6J mice were fed with a control diet (10% calories from fat) or a high fat diet (45% calories from fat), administered with saline or FVP (0.4 mg per g b.w.) by gavage over a 12-week period. In Expt. 2, mice were fed with a HFD, administered with fecal supernatants from healthy and FVP-fed donor mice for 12 weeks simultaneously. The body mass, blood lipid levels and blood glucose homeostasis of mice were analyzed, and total RNA from mouse liver and adipose tissue were extracted by TRIzol and the lipid metabolism-related gene expressions were calculated by qRT-PCR. Gut microbiota changes were evaluated by high-throughput sequencing. Results indicated that FVP and FMT supplementations showed an attenuation effect on mouse obesity, hyperlipidemia and insulin resistance. Up-regulated expressions of Ampkα1 and Ppara were found both in FVP and FMT treatment groups. Different changes were found in the gut microbiota caused by FVP and FMT, respectively. PICRUSt analysis indicated that compared with FVP supplementation, FMT showed a significant effect on regulating lipid metabolism in HFD-fed mice. The findings from this study indicated that oral administrations of FVP or FMT could significantly attenuate MS-related obesity, hyperlipidemia and insulin resistance in HFD-fed mice, and the beneficial effects may be mediated through lipid metabolism and gut microbiota regulation in different ways. These results improve the understanding of the functional activity of FVP as prebiotics.

Inhibitory effects of ß-type glycosidic polysaccharide from Pleurotus eryngii on dextran sodium sulfate-induced colitis in mice.

The aim of the present study was to determine the inhibitory effects and the potential underlying mechanisms of a novel Pleurotus eryngii ß-type glycosidic polysaccharide (WPEP) on colitis. To achieve this, sixty CD-1 (ICR) mice were divided into six groups including healthy and colitic mice treated with or without WPEP at two different doses (n = 10). The results showed that WPEP displayed a significant inhibitory effect on colitis as indicated by the lowered disease activity index in the treated colitic mice compared to the untreated colitic mice (2.78 ± 0.50 to 1.80 ± 0.17). A decrease in pro-inflammatory cytokine concentrations and pro-inflammatory protein expressions and an increase in the colon length (9.31 ± 0.59 cm to 10.89 ± 1.20 cm) along with histological improvements were also observed in the treated colitic mice compared to the untreated colitic mice in the present study. Flow cytometry and western blotting analysis revealed that these anti-colitis effects were associated with decreased accumulation of CD45+ immune cells, CD45 + F4/80+ macrophages and CD45 + Gr1+ neutrophils. Moreover, the 16s rRNA sequencing analysis of the gut microbiota revealed that WPEP partially reversed gut microbiota dysbiosis in the colitic mice including the decreased abundance of Akkermansia muciniphila (35.80 ± 9.10% to 18.24 ± 6.23%) and Clostridium cocleatum (2.34 ± 1.78% to 0.011 ± 0.003%) and the increased abundance of Bifidobacterium pseudolongum (3.48 ± 2.72% to 9.65 ± 3.74%), Lactobacillus reuteri (0.007 ± 0.002% to 0.21 ± 0.12%), Lactobacillus salivarius (1.23 ± 0.87% to 2.22 ± 1.53%) and Ruminococcus bromii (0.009 ± 0.001% to 3.83 ± 1.98%). In summary, our results demonstrated that WPEP could be utilized as a functional food component in colitis management as well as a potential prebiotic agent to improve inflammation-related disorders.

Novel green chitosan-pectin gel beads for the removal of Cu(II), Cd(II), Hg(II) and Pb(II) from aqueous solution.

Chitosan-pectin gel beads (CPBs) were synthesized via a facile and green method and applied to remove heavy metals from aqueous solution. The structural characteristics of CPBs were investigated by SEM and FTIR, the mechanical strength of CPBs was measured by Texture Analyzer and the stability of CPBs was evaluated in acidic solution. To study the adsorption characteristics, the effect of pH, contact time, initial heavy metals concentration, temperature, adsorption mechanism and regeneration were systematically investigated. The adsorption kinetics fitted well pseudo-second-order model, and the adsorption isotherms were well described by Langmuir model. The maximum adsorption capacities of Cu(II), Cd(II), Hg(II) and Pb(II) were 169.4, 177.6, 208.5 and 266.5 mg/g, respectively. The adsorption-desorption experiments revealed that the CPBs exhibited a great reusability. Thus, the synthesized CPBs in this study had the potential to be utilized as an environment-friendly and green adsorbent for the removal of heavy metals.

Potential neuroprotection of wheat alkylresorcinols in hippocampal neurons via Nrf2/ARE pathway.

5-n-Alkylresorcinols (ARs) are abundant in wheat bran and potentially antioxidative, although the neuroprotective mechanism is not fully understood. The neuroprotective effect of wheat bran ARs on H2O2-induced neuronal cells and the relationship between neuroprotection and the nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant-response element (ARE) pathway were investigated in this study. Seven homologs were identified in the purified ARs by high-performance liquid chromatography-tandem mass spectrometry. Pretreatment with 80 µg mL-1 ARs alleviated 23% HT22 cell death and the up-regulation of intracellular reactive oxygen species level and malondialdehyde under H2O2 stimulation. The neuroprotection effect was proved by the increase in the Nrf2 nuclear location and up-regulation of mRNA and protein expressions of heme oxygenase-1, NAD(P)H quinone dehydrogenase 1, glutamate-cysteine ligase catalytic subunit, and glutamate-cysteine ligase modifier subunit l. Wheat bran ARs displayed a neuroprotective function, possibly by promoting the endogenous antioxidant defense system. ARs may be regarded as a functional food ingredient for preventing neurodegenerative diseases in the future.

Preparation of newly identified polysaccharide from Pleurotus eryngii and its anti-inflammation activities potential.

The anti-inflammatory effects of two newly identified Pleurotus eryngii polysaccharides (WPEP, NPEP) were determined in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages in this study. Characterization analysis revealed that molecular weights of WPEP and NPEP were 167 and 274 kDa, and were mainly composed of glucose with ß-type glycosidic linkages. WPEP and NPEP could significantly inhibit LPS-induced inflammatory responses by regulating the production of NO, Protaglandin E2 (PGE2 ), Interleukin-1ß (IL-1ß), Tumor necrosis factor-α (TNF-α), and Interleukin-6 (IL-6). This was through the blocking of the activation of Mitogen-activated protein kinase (MAPK) pathway by inhibiting phosphorylation of p38, extracellular regulation of protein kinases 1/2, and stress-activated protein kinase/jun aminoterminal kinase. Moreover, WPEP and NPEP inhibited NF-κB signaling by reducing nuclear translocation and phosphorylation of p65. Overall, our results, for the first time identified two P. eryngii polysaccharides and demonstrated the related anti-inflammatory effects, which indicated the favorable potential of P. eryngii polysaccharide as specific functional foods. PRACTICAL APPLICATION: This study prepared and characterized newly identified Pleurotus eryngii water-soluble polysaccharide fractions and elucidated the nutritional benefits, mainly the immune response related to anti-inflammatory activities by utilizing lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Collectively, results of this study suggested that the P. eryngii polysaccharide fractions could be considered as potential candidates for exploration in the development of new immunomodulatory agent or functional supplementary foods.

Effects of a ß-type glycosidic polysaccharide from Flammulina velutipes on anti-inflammation and gut microbiota modulation in colitis mice.

Using the Flammulina velutipes polysaccharide (FVP) extracted from our previous study, herein, we investigated the improvement of this starch-free ß-type glycosidic polysaccharide in alleviating dextran sodium sulfate-induced ulcerative colitis (UC) in mice. The absolute and relative abundance of intestinal microbes in the mouse feces were both determined by 16s RNA gene sequencing. The results from the histological analysis indicate that FVP treatment reduced the symptoms of UC, up- or down-regulated the relative gene expression levels in the colon tissue, and enhanced the capacity of metabolic and biogenesis in the UC mice, as predicted by PICRUSt. 11 species of gut microbes including Lactobacillus, Bifidobacterium, and Clostridium associated with UC symptoms were analyzed by correlation analysis. Our findings suggest that FVP can alleviate the UC symptoms in mice by regulating specific gut microbes, improving the understanding of the functional activity of FVPs as prebiotics.

Gastrointestinal fate and antioxidation of ß-carotene emulsion prepared by oat protein isolate-Pleurotus ostreatus ß-glucan conjugate.

ß-carotene has been often used as a hydrophobic nutrient in many functional foods owning to its excellent antioxidant activity. However, the poor orally bioavailability of ß-carotene limits its utilization. To overcome such limitation, a delivery system was designed for the encapsulation of ß-carotene based on oil-in-water emulsion stabilized by oat protein isolate - Pleurotus ostreatus ß-glucan Maillard conjugate. The results showed that such conjugate protected emulsion against environmental stresses by increasing steric and electrostatic repulsion between droplets, mainly manifesting as their smaller particle size and higher surface charge. Additionally, conjugate promoted lipid digestion and formation of mixed micelles, leading to an improved gastrointestinal fate of encapsulated ß-carotene, especially for its in vitro bioavailability. Such effects could enhance the cellular antioxidant activity of encapsulated ß-carotene in Caco-2 cells. Our findings confirmed that Maillard conjugate can structure an emulsion-based delivery system for the encapsulation of hydrophobic ingredients to improve their utilization.

Isolation and identification of immunomodulatory selenium-containing peptides from selenium-enriched rice protein hydrolysates.

The RAW264.7 cell model was employed to screen immunomodulatory selenium-containing peptides from selenium-enriched rice protein hydrolysates (SPHs). Moreover, the selenium-containing peptides of high-activity protein hydrolysates were purified by Sephadex G-25, and identified by reversed phase ultra performance liquid chromatography coupled with triple quadrupole time-of-flight mass spectrometry. The results showed that 25 peptide sequences containing selenomethionine (SeMet) information above 90% of probability confidence were found in a fraction of alcalase hydrolysates. SeMDPGQQ and TSeMMM of 100% probability confidence were speculated as two novel selenium-containing peptide sequences. The artificially synthesized peptide TSeMMM was subsequently verified by an excellent immunomodulatory activity at a concentration of 80 µg/mL. In conclusion, the immunomodulatory activity of SPHs was correlated to SeMet sequence in the structure of selenium-containing peptides, and TSeMMM with a stronger immunomodulatory activity demonstrated potential as functional food additives for improving human health.

In vitro bioaccessibility and speciation changes of selenium in Pleurotus eryngii during the growing stage.

The production of Pleurotus eryngii by selenium (Se) biofortification is an effective way to improve the demand for Se in humans. In order to investigate the Se bioaccessibility and speciation of Se-enriched P. eryngii during the growing stage, the Se distribution in biochemical fractions, and the molecular weight and the Se species of Se-containing compounds derived from in vitro simulated gastrointestinal fluids were analyzed by size exclusion and anion exchange-high performance liquid chromatography and inductively coupled plasma mass spectrometry. The results showed that albumin had the highest Se content among biochemical fractions, approximately 34.40% of total Se, followed by glutelin, globulin and gliadins. Selenomethionine that was proved to be the major Se species would increase with P. eryngii growing from 45.85% to 59.32%, while selenocysteine would decrease from 40.68% to 15.17% of total Se. In conclusion, selenocysteine would gradually convert to selenomethionine, and thus the bioaccessibility of Se was greater in mature P. eryngii than in younger mushrooms.

Polyphenols-rich extract from Pleurotus eryngii with growth inhibitory of HCT116 colon cancer cells and anti-inflammatory function in RAW264.7 cells.

Edible mushrooms are rich sources of bioactive components. In this study, a polyphenol-rich extract, designated as PPEP, was isolated from an edible mushroom, Pleurotus eryngii. Using ultra high performance liquid chromatograph combined with triple time-of-flight mass spectrometry (UPLC-TOF/MS/MS), gallic acid monohydrate, 3-(3,4-dihydroxyphenyl)-propionic acid, methyl gallate, syringic acid, ellagic acid and catechin were identified in PPEP. This phenolic-rich extract PPEP exhibited anti-inflammatory effect in lipopolysaccharide-stimulated RAW264.7 macrophages by inhibiting the overproduction of pro-inflammatory mediators including nitric oxide (NO) and reactive oxygen species (ROS). It was demonstrated that the anti-inflammatory effects of PPEP were associated with the inhibition of iNOS expression, suppression of p-IκB protein expression and inhibition of NF-κB and IκB mRNA expression. Next, the inhibitory effect of PPEP against human colon cancer cells was also determined. PPEP suppressed cell proliferation of human colon cancer HCT116 cells in a dose- and time-dependent fashion, while it showed no inhibitory effect on normal human colonic myofibroblasts CCD-18Co cells at the same tested concentrations (0-200 µg mL-1). Moreover, PPEP induced cell cycle arrest and led to extensive cellular apoptosis in human colon cancer cells, which was associated with the downregulation of cell cycle-related signaling protein, e.g. cyclin B and cyclin E, and the upregulation of apoptosis-related signaling protein caspase-3 and cleaved caspase-3. Overall, our results provided a basis for using PPEP as a promising preventive agent against inflammatory disease and colon cancer.

Flammulina velutipes polysaccharides improve scopolamine-induced learning and memory impairment in mice by modulating gut microbiota composition.

Flammulina velutipes polysaccharides (FVP) have been proved to be effective in improving learning and memory impairment in mice. However, their underlying mechanism remains unclear. The aim of this study was to investigate the relationship between memory improvement and gut microbiota regulation of FVP. The results showed a significant decrease in the relative abundances of Clostridia and Bacilli but a significant increase in Bacteroidia, Erysipelotrichia and Actinobacteria in the FVP-treated group versus the control group. Fecal microbiota transplantation of mice with 'FVP microbiota' derived from FVP-fed mice resulted in improved learning and memory function compared to colonization with 'common microbiota' derived from control individuals. FVP and 'FVP microbiota' significantly increased the numbers of platform crossings and the swimming distance of mice in the probe test and decreased the escape latency and total swimming distance of mice in the hidden platform test. Moreover, FVP and 'FVP microbiota' regulated cytokines, such as IL-1ß, TNF-α, IL-6 and IL-10, suggesting a mechanism involving the suppression of neuroinflammation. This study indicated that the regulation of the gut microbiome may have a causal role in improving scopolamine-induced impairment of learning and memory.

Enrichment of Bread with Nutraceutical-Rich Mushrooms: Impact of Auricularia auricula (Mushroom) Flour Upon Quality Attributes of Wheat Dough and Bread.

Edible mushrooms contain a variety of bioactive molecules that may enhance human health and wellbeing. Consequently, there is increasing interest in fortifying functional foods with these nutraceutical-rich substances. However, incorporation of mushroom-based ingredients into foods should not adversely affect the quality attributes of the final product. In this study, the impact of incorporating powdered Auricularia auricula, a widely consumed edible mushroom, into bread products was examined. The rheological and structural properties of wheat dough and bread supplemented with 0% to 10% (w/w) A. auricula flour were measured. Supplementation of wheat doughs with A. auricula flour increased the peak viscosity and enhanced their water holding capacity. Rapid viscosity analysis showed that peak and final viscosities of the blended flour (wheat flour with A. auricula flour) were higher than wheat flour alone. However, dough stability and elastic modulus were reduced by blending wheat flour with A. auricula flour. SEM observation showed that doughs with up to 5% (w/w) A. auricula flour had acceptable gluten network microstructure. Characterization of the quality attributes of bread indicated that incorporation of A. auricula flour at levels >5% negatively impacted bread volume, height, texture, and appearance.

Evaluation of anti-fatigue property of the extruded product of cereal grains mixed with Cordyceps militaris on mice.

BACKGROUND: Fatigue is a biological phenomenon that involves a feeling of extreme physical or mental tiredness that could potentially cause some severe chronic diseases. Recently, diet therapy has provided a new alternative to alleviate physical fatigue. In our previous study, addition of Cordyceps militaris (C. militaris) into an extruded product was shown to provide high nutrition and unique flavors; however, little is known whether this product has some scientific evidence regarding anti-fatigue property. The purpose of this study was to evaluate the anti-fatigue effects of extruded products of cereal grains (EC) and EC mixed with C. militaris (ECC). METHODS: The mice were divided into seven groups: one group received distilled water (Control group, n = 20), and the other groups received different dosages of EC (5, 10 and 20 g/kg body weight, n = 20 per group) or of ECC (5, 10 and 20 g/kg body weight, n = 20 per group) solution in water. All of the mice were administered with distilled water, EC or ECC continuously for 30 days by gavage and the anti-fatigue activity was evaluated using a weight-loaded swimming test, along with assessments of fatigue-related indicators. The mode of fighting fatigue was investigated by determining changes in exercise endurance and biochemical markers, including exhaustive swimming time, lactate dehydrogenase (LDH), blood lactic acid (BLA), creatine kinase (CK), blood urea nitrogen (BUN), malondialdehyde (MDA), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), catalase (CAT), and hepatic and muscle glycogen levels. RESULTS: EC and ECC prolonged the swimming endurance time of mice compared to the control. The content of BLA at high dose of ECC group (20 g/kg) was significantly lower than that in the negative control group. CK, BUN and MDA levels were significantly reduced by treatment with EC and ECC compared to the negative control, while the low and middle dose of EC had no significant effect on MDA levels. Additionally, only the middle and high dose of EC (10, 20 g/kg) could significantly decrease the BUN level. EC and ECC treatments increased glycogen, LDH, SOD, CAT and GSH-Px levels. Low and middle dose of EC had no significant effects on muscle glycogen. Moreover, low dose of EC could increase the level of SOD but it was not statistically significant. Compared to the EC treatment groups, ECC demonstrated the efficacy of anti-fatigue potential, particularly at a high dose of ECC, the best performance in relieving fatigue. CONCLUSIONS: These results suggest that EC and ECC could prevent exercise-induced fatigue in mice and ECC provided a better effect. In addition, C. militaris in ECC might play a crucial role in the anti-fatigue activity of ECC.

The Correlation Between In Vitro Antioxidant Activity and Immunomodulatory Activity of Enzymatic Hydrolysates from Selenium-Enriched Rice Protein.

The antioxidant and immunomodulatory activities of selenium-enriched rice protein hydrolysates (Se-PH) were evaluated by a cellular antioxidant activity test and macrophage proliferation and phagocytosis assays, respectively. The results showed that trypsin hydrolysate provided the highest proliferation rate of 60.91% at a concentration of 100 µg/mL. Moreover, a remarkable rise in the phagocytosis rates for trypsin hydrolysate (64.1%) and pepsin-trypsin hydrolysate (54.5%) was observed when the sample concentrations were increased to 50 µg/mL. A positive correlation was found between the phagocytic ability of macrophages and both the selenium concentration and the degree of hydrolysis of Se-PH, and the correlation coefficients R obtained were 0.792 and 0.930 (P < 0.05), respectively. The capacity of Se-PH to inhibit the oxidation of dichlorodihydrofluorescein had a significant negative correlation with the phagocytic ability of macrophages (R = -0.840, P < 0.05). In conclusion, a positive correlation was found between the antioxidant activity and the immunomodulatory activity of Se-PH, which could be used as potential functional food additives for improving human health.