Microanalysis Characterization and Immunomodulatory Effect for Selenium-Enriched Polysaccharide from Morchella esculenta (L.) Pers.

Morchella esculenta (L.) Pers., referred to as Morel, is a medicinal and edible homologous fungus, which contains many bioactive substances. In Morel, polysaccharides are the most abundant and have various bioactivities. In the present work, two novel polysaccharides, Se-MPS and MPS, were prepared and purified from selenium-enriched (Se-enriched) and common Morel mycelia, respectively, and their structural and immunomodulatory properties were evaluated. The results show that Se-enriched treatment significantly changed the polysaccharides' chemical composition, molecular weight, and sugar chain configuration. In addition, the Se-enriched treatment also improved the polysaccharides' fragmentation and thermal stability. Importantly, Se-enriched Morel polysaccharide (Se-MPS) could significantly enhance phagocytosis of RAW 264.7 macrophage cells and, remarkably, activate their immune response via activating the TLR4-TRAF6-MAPKs-NF-κB cascade signaling pathway, finally exerting an immunomodulatory function. Based on these findings, selenium-enriched Morel polysaccharide appears to have more potential for development and utilization in functional foods or medicines than ordinary Morel polysaccharide.

Jasmonic Acid Plays a Pivotal Role in Pollen Development and Fertility Regulation in Different Types of P(T)GMS Rice Lines.

Two-line hybrid rice systems represent a new technical approach to utilizing the advantages of rice hybrids. However, the mechanism underlying the male sterile-line fertility transition in rice remains unclear. Peiai 64S (PA64S) is a photoperiod- and thermo-sensitive genic male sterile (PTGMS) line in which male sterility manifests at an average temperature above 23.5 °C under long-day (LD) conditions. Nongken 58S (NK58S) is a LD-sensitive genic male sterile (PGMS) rice that is sterile under LD conditions (above 13.75 h-day). In contrast, D52S is a short-day (SD)-PGMS line that manifests male sterility under SD conditions (below 13.5 h-day). In this study, we obtained fertile and sterile plants from all three lines and performed transcriptome analyses on the anthers of the plants. Gene ontology (GO) analysis suggested that the differentially expressed genes identified were significantly enriched in common terms involved in the response to jasmonic acid (JA) and in JA biosynthesis. On the basis of the biochemical and molecular validation of dynamic, tissue-specific changes in JA, indole-3-acetic acid (IAA) levels, gibberellin (GA) levels, and JA biosynthetic enzyme activities and expression, we proposed that JA could play a pivotal role in viable pollen production through its initial upregulation, constant fluctuation and leaf-spikelet signaling under certain fertility-inducing conditions. Furthermore, we also sprayed methyl jasmonate (MEJA) and salicylhydroxamic acid (SHAM) on the plants, thereby achieving fertility reversal in the PGMS lines NK58S and D52S, with 12.91-63.53% pollen fertility changes. Through qPCR and enzyme activity analyses, we identified two key enzymes-allene oxide synthase (AOS) and allene oxide cyclase (AOC)-that were produced and upregulated by 20-500-fold in PGMS in response to spraying; the activities of these enzymes reversed pollen fertility by influencing the JA biosynthetic pathway. These results provide a new understanding of hormone interactions and networks in male-sterile rice based on the role of JA that will help us to better understand the potential regulatory mechanisms of fertility development in rice in the future.

Advances in the knowledge of adaptive mechanisms mediating abiotic stress responses in Camellia sinensis.

Abiotic stresses are wide-ranging environmental factors that adversely affect the yield and quality of tea plants (Camellia sinensis). As perennial woody economic plants, various environmental factors affect its growth and development. To survive under stress conditions, plants adapt to or withstand these adverse external environments by regulating their growth and morphological structure. Recently, there have been knowledges regarding the significant progress in the mechanisms of abiotic stresses (including cold and heat, drought, salt and heavy metal stresses) tolerance in tea plants. Many evidences suggest that several phytohormones are in response to various environmental stresses, and regulate plant stress adaptation. However, the regulatory mechanisms of plant abiotic stress responses and resistance remain unclear. In this review, we mainly summarize the studies on the adaptive physiological and molecular mechanisms of tea plants under abiotic stress, and discuss the direction for tea plant resistance and breeding strategies.

Improvement of Biological Activity of Morchella esculenta Protein Hydrolysate by Microwave-Assisted Selenization.

Morchella esculenta protein hydrolysate (MPH) from a valued medicinal and edible fungus M. esculenta (L.) is an excellent material for functional food development. To promote MPH utilization, selenization of MPH was performed by applying a simple and environmentally friendly microwave irradiation procedure. The physicochemical characteristics of selenized MPH (Se-MPH) were investigated by SEM-EDX, FTIR, CD, and amino acid analyzer, and its biological activity were assessed by ABTS, DPPH, H2 O2 scavenging, and reducing power assays, as well as α-glucosidase, α-amylase, and tyrosinase inhibition tests. The results showed that MPH was successfully selenized, Se content in Se-MPH reached 59.0 ± 0.64 mg/g, and amino groups, hydroxyl groups, and sulfur atoms of methionine residues in the MPH molecule may participate in selenization. Furthermore, Se-MPH exhibited significantly enhanced antioxidant, antidiabetic, and tyrosinase inhibitory activities, compared with the native MPH and microwave-irradiated MPH. Thus, the microwave-assisted selenization is a feasible strategy for preparing organic Se and improving the biological activity of MPH. PRACTICAL APPLICATION: In this study, selenized Morchella esculenta protein hydrolysate (Se-MPH) was successfully prepared via conjugation with sodium selenite using the microwave-assisted method. The results showed that Se-MPH, synthesized with the aid of microwave, exhibited favorable selenium content and improved antioxidant, antidiabetic, and tyrosinase inhibitory activities. Therefore, microwave can be employed as an innovative and effective avenue for the production of organic selenium in nutraceutical and functional food industry.

Selenium Polysaccharide SPMP-2a from Pleurotus geesteranus Alleviates H2O2-Induced Oxidative Damage in HaCaT Cells.

Selenium- (Se-) enriched polysaccharide SPMP-2a was extracted and purified from Pleurotus geesteranus. SPMP-2a is a white flocculent polysaccharide and soluble in water, with a molecular weight of 3.32 × 104 Da. Fourier transform infrared spectroscopy spectral analysis indicated that it belongs to an acid Se polysaccharide with α-D-glucopyranoside bond. The effects of Se polysaccharide SPMP-2a in P. geesteranus against hydrogen peroxide- (H2O2-) induced oxidative damage in human keratinocytes (HaCaT) cells were evaluated further. Reduced cell viability and elevated apoptotic rates in H2O2-treated HaCaT cells were proven by MTT and flow cytometry assays. Hoechst 33342 staining revealed chromatin condensations in the nuclei of HaCaT cells. However, with the addition of SPMP-2a, cell viability improved, nuclear condensation declined, and cell apoptotic rates dropped significantly. Ultrastructural observation consistently revealed that treatments with SPMP-2a reduced the number of swollen and vacuolar mitochondria in the H2O2-treated cells compared with the controls. Furthermore, SPMP-2a increased the superoxide dismutase (SOD) and catalase (CAT) activities and reduced reactive oxygen species (ROS) content. Western blot analysis showed that SPMP-2a treatment effectively increased B-cell lymphoma 2 (Bcl-2) protein expression. Therefore, SPMP-2a could improve cellular antioxidant enzyme activities, reduce ROS levels, and increase Bcl-2 protein expression levels, thereby reducing cell apoptosis and protecting HaCaT cells from H2O2-induced oxidative damage.

Protective effects of aucubin on osteoarthritic chondrocyte model induced by hydrogen peroxide and mechanical stimulus.

BACKGROUND: During the onset of osteoarthritis (OA), certain biochemical events have been shown to accelerate cartilage degradation, including the dysregulation of cartilage ECM anabolism, abnormal generation of reactive oxygen species (ROS) and overproduction of proteolytic enzymes and inflammatory cytokines. The potency of aucubin in protecting cellular components against oxidative stress, inflammation and apoptosis effects are well documented, which makes it a potential candidate for OA treatment. In this study, we aimed to evaluate the protective benefits of aucubin against OA using H2O2 and compression induced OA-like chondrocyte models. METHODS: The effects of aucubin were studied in porcine chondrocytes after 1 mM H2O2 stimulation for 30 min or sustained compression for 24 h. Effects of aucubin on cell proliferation and cytotoxicity of chondrocytes were measured with WST-1 and LDH assays. ROS production was evaluated by the Total ROS/Superoxide Detection Kit. Caspase-3 activity was evaluated by the CaspACE assay system. The levels of apoptosis were evaluated by the Annexin V-FITC apoptosis detection kit. OA-related gene expression was measured by reverse transcription quantitative polymerase chain reaction (RT-qPCR). Total DNA quantification was evaluated by the DNeasy Blood and Tissue kit. Sulfated-glycosaminoglycans (sGAGs) production and content were evaluated by DMMB assay and Alcian blue staining. RESULTS: The results showed that the ROS scavenge effects of aucubin appeared after 1 h of pretreatment. Aucubin could reduce the caspase-3 activity induced by H2O2, and reduced the apoptosis cell population in flowcytometry. In RT-qPCR results, aucubin could maintain ACAN and COL2A1 gene expressions, and prevent IL6 and MMP13 gene up-regulation induced by H2O2 and compression stimulations. In the DMMB assay and Alcian blue staining, aucubin could maintain the sGAG content and protect chondrocytes against compressive stress, but not oxidative stress from H2O2. CONCLUSIONS: These results indicated that aucubin has protective effects in an osteoarthritic chondrocyte model induced by H2O2 and mechanical stimulus.

[Study on the extraction of mycelium polysaccharides from selenium-rich Morchella esculenta with neutral proteinase method].

OBJECTIVE: To study the extraction conditions of mycelium polysaccharides from selenium-rich Morchella esculenta with neutral proteinase for increasing of yield. METHODS: On the basis of single factor tests, orthogonal experiment design was applied to analyze the influence of factors including enzyme dosage, enzymolysis time, enzymolysis temperature and material/liquid ratio on the extraction rate of the polysaccharides. RESULTS: The optimal extraction conditions of mycelium polysaccharides from selenium-rich Morchella esculenta was as follows: enzyme dosage was 1.5%, enzymolysis time was 2 h, enzymolysis temperature was 40 degrees C, and material/liquid ratio was 1:15. The extraction rate of polysaccharide was 11.26% under the extraction conditions. CONCLUSION: The process is simple, stable and practicable, and can be used for the extraction of mycelium polysaccharides from selenium-rich Morchella esculenta.

[Purification and analysis of Cimicifuga foetida glycoprotein ( CF- I )].

A kind of glycoprotein ( CF- I ) was extracted from Cimicifuga foetida and purified by DEAE-Cellulose ( DEAE-52) and Sepharose CL-4B. It was identified to be homogeneous glycoprotein complex by electrophoresis and fast protein liquid chromatography (FPLC). alpha-glucosidic bond was detrermined by IR. Typical absorption of polysaccharide was shown in its IR spectrum. It had no typical absorption of nucleic acid or pigment by UV scanning. Glucose, galactose, mannose and arabinose were identified in CF- I with the molar ratio of 11. 94: 2. 18: 1. 38: 1 by GC. Its average MW was estimated to be 5. 8 x 10' by gel filtration. The content of total saccharide, protein and acid polysaccharide was 78% , 14. 4% and 23% respectively. It might be composed of 1-->4 and 1-->6 linked glucopyranose by periodate oxidation and Smith degration.